Parsimonious model for blood glucose level monitoring in type 2 diabetes patients.

PubMed

Zhao, Fang; Ma, Yan Fen; Wen, Jing Xiao; DU, Yan Fang; Li, Chun Lin; Li, Guang Wei

2014-07-01

To establish the parsimonious model for blood glucose monitoring in patients with type 2 diabetes receiving oral hypoglycemic agent treatment. One hundred and fifty-nine adult Chinese type 2 diabetes patients were randomized to receive rapid-acting or sustained-release gliclazide therapy for 12 weeks. Their blood glucose levels were measured at 10 time points in a 24 h period before and after treatment, and the 24 h mean blood glucose levels were measured. Contribution of blood glucose levels to the mean blood glucose level and HbA1c was assessed by multiple regression analysis. The correlation coefficients of blood glucose level measured at 10 time points to the daily MBG were 0.58-0.74 and 0.59-0.79, respectively, before and after treatment (P<0.0001). The multiple stepwise regression analysis showed that the blood glucose levels measured at 6 of the 10 time points could explain 95% and 97% of the changes in MBG before and after treatment. The three blood glucose levels, which were measured at fasting, 2 h after breakfast and before dinner, of the 10 time points could explain 84% and 86% of the changes in MBG before and after treatment, but could only explain 36% and 26% of the changes in HbA1c before and after treatment, and they had a poorer correlation with the HbA1c than with the 24 h MBG. The blood glucose levels measured at fasting, 2 h after breakfast and before dinner truly reflected the change 24 h blood glucose level, suggesting that they are appropriate for the self-monitoring of blood glucose levels in diabetes patients receiving oral anti-diabetes therapy. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

[Design and implementation of real-time continuous glucose monitoring instrument].

PubMed

Huang, Yonghong; Liu, Hongying; Tian, Senfu; Jia, Ziru; Wang, Zi; Pi, Xitian

2017-12-01

Real-time continuous glucose monitoring can help diabetics to control blood sugar levels within the normal range. However, in the process of practical monitoring, the output of real-time continuous glucose monitoring system is susceptible to glucose sensor and environment noise, which will influence the measurement accuracy of the system. Aiming at this problem, a dual-calibration algorithm for the moving-window double-layer filtering algorithm combined with real-time self-compensation calibration algorithm is proposed in this paper, which can realize the signal drift compensation for current data. And a real-time continuous glucose monitoring instrument based on this study was designed. This real-time continuous glucose monitoring instrument consisted of an adjustable excitation voltage module, a current-voltage converter module, a microprocessor and a wireless transceiver module. For portability, the size of the device was only 40 mm × 30 mm × 5 mm and its weight was only 30 g. In addition, a communication command code algorithm was designed to ensure the security and integrity of data transmission in this study. Results of experiments in vitro showed that current detection of the device worked effectively. A 5-hour monitoring of blood glucose level in vivo showed that the device could continuously monitor blood glucose in real time. The relative error of monitoring results of the designed device ranged from 2.22% to 7.17% when comparing to a portable blood meter.

Blood glucose level reconstruction as a function of transcapillary glucose transport.

PubMed

Koutny, Tomas

2014-10-01

A diabetic patient occasionally undergoes a detailed monitoring of their glucose levels. Over the course of a few days, a monitoring system provides a detailed track of their interstitial fluid glucose levels measured in their subcutaneous tissue. A discrepancy in the blood and interstitial fluid glucose levels is unimportant because the blood glucose levels are not measured continuously. Approximately five blood glucose level samples are taken per day, and the interstitial fluid glucose level is usually measured every 5min. An increased frequency of blood glucose level sampling would cause discomfort for the patient; thus, there is a need for methods to estimate blood glucose levels from the glucose levels measured in subcutaneous tissue. The Steil-Rebrin model is widely used to describe the relationship between blood and interstitial fluid glucose dynamics. However, we measured glucose level patterns for which the Steil-Rebrin model does not hold. Therefore, we based our research on a different model that relates present blood and interstitial fluid glucose levels to future interstitial fluid glucose levels. Using this model, we derived an improved model for calculating blood glucose levels. In the experiments conducted, this model outperformed the Steil-Rebrin model while introducing no additional requirements for glucose sample collection. In subcutaneous tissue, 26.71% of the calculated blood glucose levels had absolute values of relative differences from smoothed measured blood glucose levels less than or equal to 5% using the Steil-Rebrin model. However, the same difference interval was encountered in 63.01% of the calculated blood glucose levels using the proposed model. In addition, 79.45% of the levels calculated with the Steil-Rebrin model compared with 95.21% of the levels calculated with the proposed model had 20% difference intervals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of urine glucose meter based on micro-planer amperometric biosensor and its clinical application for self-monitoring of urine glucose.

PubMed

Miyashita, Mariko; Ito, Narushi; Ikeda, Satoshi; Murayama, Tatsuro; Oguma, Koji; Kimura, Jun

2009-01-01

The highly sensitive urine glucose meter based on amperometric glucose sensor was developed and commercialized. It shows remarkable performances of wide measurement range in 0-2000 mgdl(-1), rapid response time as 6s and robustness against influence by interferents like ascorbic acid or acetaminophen. Correlation between the developed urine glucose meter and commercialized clinical-use urine glucose analyzer showed excellent linear relationship. The monitoring of postmeal blood glucose levels by assess of urine glucose of actual subjects was performed with the developed urine glucose meter. The experimental results suggest the urine glucose level 120 min following the meal should be the appropriate index for diabetes or impaired glucose tolerance to control blood glucose level. The new portable meter was developed, and is expected for flexible use at places other than home or office.

Blood glucose self-monitoring patterns in Mexican Americans: further lessons from the Starr County Border Health Initiative.

PubMed

Cuevas, Heather E; Brown, Sharon A; García, Alexandra A; Winter, Mary; Brown, Adama; Hanis, Craig L

2015-02-01

The purpose was to describe patterns of home self-monitoring of blood glucose (SMBG) in Mexican Americans with type 2 diabetes mellitus enrolled in a diabetes self-management education protocol. Research questions were as follows: (1) What were the patterns and rates of home glucose self-monitoring over the 6-month course of the study? (2) What were the differences in monitoring rates between experimental and control groups? (3) What were the relationships between rates of monitoring and glycosylated hemoglobin (A1C), gender, and years with diabetes? We used a randomized (by group) repeated-measures pretest/posttest control group design. Glucometer data from an experimental group (diabetes self-management education plus nurse case management) and a comparison group (diabetes self-management education only) were analyzed. Data were collected at baseline and at 3 and 6 months. Overall average SMBG rates were low. Experimental and control group monitoring levels were not significantly different. More females than males never monitored glucose values, but more females than males checked at least one time per week. Those participants who checked their glucose levels more than once per week had diabetes for a longer period of time. Rates of monitoring were not strongly associated with A1C levels at 3 and 6 months, but at 6 months A1C levels were statistically significantly different based on whether or not individuals monitored their glucose levels (P=0.03, n=71). SMBG rates were low in this study despite SMBG education and access to free glucometers and test strips. The lower rates of SMBG may reflect the effects of unexpected environmental challenges, but exact causes remain unclear. Reasons for low rates of SMBG need to be explored further, especially in underserved communities.

Comparison of tofogliflozin 20 mg and ipragliflozin 50 mg used together with insulin glargine 300 U/mL using continuous glucose monitoring (CGM): A randomized crossover study.

PubMed

Takeishi, Soichi; Tsuboi, Hiroki; Takekoshi, Shodo

2017-10-28

To investigate whether sodium glucose co-transporter 2 inhibitors (SGLT2i), tofogliflozin or ipragliflozin, achieve optimal glycemic variability, when used together with insulin glargine 300 U/mL (Glargine 300). Thirty patients with type 2 diabetes were randomly allocated to 2 groups. For the first group: After admission, tofogliflozin 20 mg was administered; Fasting plasma glucose (FPG) levels were titrated using an algorithm and stabilized at 80 mg/dL level with Glargine 300 for 5 days; Next, glucose levels were continuously monitored for 2 days using continuous glucose monitoring (CGM); Tofogliflozin was then washed out over 5 days; Subsequently, ipragliflozin 50 mg was administered; FPG levels were titrated using the same algorithm and stabilized at 80 mg/dL level with Glargine 300 for 5 days; Next, glucose levels were continuously monitored for 2 days using CGM. For the second group, ipragliflozin was administered prior to tofogliflozin, and the same regimen was maintained. Glargine 300 and SGLT2i were administered at 8:00 AM. Data collected on the second day of measurement (mean amplitude of glycemic excursion [MAGE], average daily risk range [ADRR]; on all days of measurement) were analyzed. Area over the glucose curve (<70 mg/dL; 0:00 to 6:00, 24-h), M value, standard deviation, MAGE, ADRR, and mean glucose levels (24-h, 8:00 to 24:00) were significantly lower in patients on tofogliflozin than in those on ipragliflozin. Tofogliflozin, which reduces glycemic variability by preventing nocturnal hypoglycemia and decreasing postprandial glucose levels, is an ideal SGLT2i when used together with Glargine 300 during basal insulin therapy.

Generation of an immortalized mesenchymal stem cell line producing a secreted biosensor protein for glucose monitoring

PubMed Central

Weisman, Itamar; Romano, Jacob; Ivics, Zoltán; Izsvák, Zsuzsanna; Barkai, Uriel

2017-01-01

Diabetes is a chronic disease characterized by high levels of blood glucose. Diabetic patients should normalize these levels in order to avoid short and long term clinical complications. Presently, blood glucose monitoring is dependent on frequent finger pricking and enzyme based systems that analyze the drawn blood. Continuous blood glucose monitors are already on market but suffer from technical problems, inaccuracy and short operation time. A novel approach for continuous glucose monitoring is the development of implantable cell-based biosensors that emit light signals corresponding to glucose concentrations. Such devices use genetically modified cells expressing chimeric genes with glucose binding properties. MSCs are good candidates as carrier cells, as they can be genetically engineered and expanded into large numbers. They also possess immunomodulatory properties that, by reducing local inflammation, may assist long operation time. Here, we generated a novel immortalized human MSC line co-expressing hTERT and a secreted glucose biosensor transgene using the Sleeping Beauty transposon technology. Genetically modified hMSCs retained their mesenchymal characteristics. Stable transgene expression was validated biochemically. Increased activity of hTERT was accompanied by elevated and constant level of stem cell pluripotency markers and subsequently, by MSC immortalization. Furthermore, these cells efficiently suppressed PBMC proliferation in MLR transwell assays, indicating that they possess immunomodulatory properties. Finally, biosensor protein produced by MSCs was used to quantify glucose in cell-free assays. Our results indicate that our immortalized MSCs are suitable for measuring glucose concentrations in a physiological range. Thus, they are appropriate for incorporation into a cell-based, immune-privileged, glucose-monitoring medical device. PMID:28949988

Generation of an immortalized mesenchymal stem cell line producing a secreted biosensor protein for glucose monitoring.

PubMed

Siska, Evangelia K; Weisman, Itamar; Romano, Jacob; Ivics, Zoltán; Izsvák, Zsuzsanna; Barkai, Uriel; Petrakis, Spyros; Koliakos, George

2017-01-01

Diabetes is a chronic disease characterized by high levels of blood glucose. Diabetic patients should normalize these levels in order to avoid short and long term clinical complications. Presently, blood glucose monitoring is dependent on frequent finger pricking and enzyme based systems that analyze the drawn blood. Continuous blood glucose monitors are already on market but suffer from technical problems, inaccuracy and short operation time. A novel approach for continuous glucose monitoring is the development of implantable cell-based biosensors that emit light signals corresponding to glucose concentrations. Such devices use genetically modified cells expressing chimeric genes with glucose binding properties. MSCs are good candidates as carrier cells, as they can be genetically engineered and expanded into large numbers. They also possess immunomodulatory properties that, by reducing local inflammation, may assist long operation time. Here, we generated a novel immortalized human MSC line co-expressing hTERT and a secreted glucose biosensor transgene using the Sleeping Beauty transposon technology. Genetically modified hMSCs retained their mesenchymal characteristics. Stable transgene expression was validated biochemically. Increased activity of hTERT was accompanied by elevated and constant level of stem cell pluripotency markers and subsequently, by MSC immortalization. Furthermore, these cells efficiently suppressed PBMC proliferation in MLR transwell assays, indicating that they possess immunomodulatory properties. Finally, biosensor protein produced by MSCs was used to quantify glucose in cell-free assays. Our results indicate that our immortalized MSCs are suitable for measuring glucose concentrations in a physiological range. Thus, they are appropriate for incorporation into a cell-based, immune-privileged, glucose-monitoring medical device.

Cot-side electro-encephalography and interstitial glucose monitoring during insulin-induced hypoglycaemia in newborn lambs.

PubMed

Harris, Deborah L; Battin, Malcolm R; Williams, Chris E; Weston, Philip J; Harding, Jane E

2009-01-01

The optimal approach to detection and management of neonatal hypoglycaemia remains unclear. We sought to demonstrate whether electro-encephalography (EEG) changes could be detected on the amplitude-integrated EEG monitor during induced hypoglycaemia in newborn lambs, and also to determine the accuracy of continuously measured interstitial glucose in this situation. Needle electrodes were placed in the P3-P4, O1-O2 montages. The interstitial glucose sensor was placed subcutaneously. After 30 min baseline recordings, hypoglycaemia was induced by insulin infusion and blood glucose levels were monitored every 5 min. The infusion was adjusted to reduce blood glucose levels by 0.5 mmol/l every 15 min and then maintain a blood glucose level <1.0 mmol/l for 4 h. EEG parameters analysed included amplitude, continuity and spectral edge frequency. The interstitial and blood glucose levels were compared. All lambs (n = 15, aged 3-11 days) became hypoglycaemic, with median blood glucose levels falling from 6.5 to 1.0 mmol/l, p < 0.0001. There were no detectable changes in any of the measured EEG parameters related to hypoglycaemia, although seizures occurred in 2 lambs. There was moderate agreement between the intermittent blood glucose and continuous interstitial glucose measurements in the baseline, decline, and hypoglycaemia periods (mean difference -0.7 mmol/l, 95% confidence interval, CI, -2.8 to 1.4 mmol/l). However, agreement was poor during reversal of hypoglycaemia (mean difference 4.5 mmol/l, 95% CI -1.1 to 10.7 mmol/l). The cot-side EEG may not be a useful clinical tool in the detection of neurological changes induced by hypoglycaemia. However, continuous interstitial glucose monitoring may be useful in the management of babies at risk of hypoglycaemia. (c) 2008 S. Karger AG, Basel.

Evaluation of a minimally invasive system for measuring glucose area under the curve during oral glucose tolerance tests: usefulness of sweat monitoring for precise measurement.

PubMed

Sakaguchi, Kazuhiko; Hirota, Yushi; Hashimoto, Naoko; Ogawa, Wataru; Hamaguchi, Tomoya; Matsuo, Toshihiro; Miyagawa, Jun-ichiro; Namba, Mitsuyoshi; Sato, Toshiyuki; Okada, Seiki; Tomita, Koji; Matsuhisa, Munehide; Kaneto, Hideaki; Kosugi, Keisuke; Maegawa, Hiroshi; Nakajima, Hiromu; Kashiwagi, Atsunori

2013-05-01

We developed a system for measuring glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET). Sweat contamination during interstitial fluid glucose (IG) extraction affects the accuracy of glucose AUC measurement, because this technology uses extracted sodium ion levels as an internal standard. Therefore, we developed a sweat monitoring patch to reduce this effect and investigated its efficacy in volunteers undergoing oral glucose tolerance tests (OGTTs). Fifty diabetes mellitus inpatients and 10 healthy subjects undergoing the 75 g OGTT were included. Two sites on the forearm were pretreated with microneedle arrays, then hydrogels for interstitial fluid extraction were placed on the treated sites. Simultaneously, hydrogels for sweat monitoring were placed on untreated sites near the treated sites. Plasma glucose (PG) levels were measured every 30 min for 2 h to calculate reference AUC values. Using MIET, IG AUC was calculated from extracted glucose and sodium ion levels after attachment of the hydrogel for 2 h. Good correlation between IG AUC measurements using MIET and reference AUCs measured using PG levels was confirmed over a wide AUC range (202-610 mg/h/dl) after correction for the sweat-induced error detected by the hydrogel patches on the nonpretreated skin. Strong correlation between IG AUC and peak glucose levels indicates that glucose spikes can be easily detected by this system. We confirmed the effectiveness of a sweat monitoring patch for precise AUC measurement using MIET. This novel, easy-to-use system has potential for glucose excursion evaluation in daily clinical practice. © 2013 Diabetes Technology Society.

Evaluation of a Minimally Invasive System for Measuring Glucose Area under the Curve during Oral Glucose Tolerance Tests: Usefulness of Sweat Monitoring for Precise Measurement

PubMed Central

Sakaguchi, Kazuhiko; Hirota, Yushi; Hashimoto, Naoko; Ogawa, Wataru; Hamaguchi, Tomoya; Toshihiro, Matsuo; Miyagawa, Jun-ichiro; Namba, Mitsuyoshi; Sato, Toshiyuki; Okada, Seiki; Tomita, Koji; Matsuhisa, Munehide; Kaneto, Hideaki; Kosugi, Keisuke; Maegawa, Hiroshi; Nakajima, Hiromu; Kashiwagi, Atsunori

2013-01-01

Aims: We developed a system for measuring glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET). Sweat contamination during interstitial fluid glucose (IG) extraction affects the accuracy of glucose AUC measurement, because this technology uses extracted sodium ion levels as an internal standard. Therefore, we developed a sweat monitoring patch to reduce this effect and investigated its efficacy in volunteers undergoing oral glucose tolerance tests (OGTTs). Materials and Methods: Fifty diabetes mellitus inpatients and 10 healthy subjects undergoing the 75 g OGTT were included. Two sites on the forearm were pretreated with microneedle arrays, then hydrogels for interstitial fluid extraction were placed on the treated sites. Simultaneously, hydrogels for sweat monitoring were placed on untreated sites near the treated sites. Plasma glucose (PG) levels were measured every 30 min for 2 h to calculate reference AUC values. Using MIET, IG AUC was calculated from extracted glucose and sodium ion levels after attachment of the hydrogel for 2 h. Results: Good correlation between IG AUC measurements using MIET and reference AUCs measured using PG levels was confirmed over a wide AUC range (202–610 mg/h/dl) after correction for the sweat-induced error detected by the hydrogel patches on the nonpretreated skin. Strong correlation between IG AUC and peak glucose levels indicates that glucose spikes can be easily detected by this system. Conclusion: We confirmed the effectiveness of a sweat monitoring patch for precise AUC measurement using MIET. This novel, easy-to-use system has potential for glucose excursion evaluation in daily clinical practice. PMID:23759401

Development of a transcutaneous blood-constituent monitoring method using a suction effusion fluid collection technique and an ion-sensitive field-effect transistor glucose sensor.

PubMed

Ito, N; Kayashima, S; Kimura, J; Kuriyama, T; Arai, T; Kikuchi, M; Nagata, N

1994-05-01

The paper describes a method for the transcutaneous monitoring of blood constituents. It combines the use of a suction effusion fluid (SEF) collecting technique with a silicon on sapphire/ion-sensitive field-effect transistor (SOS/ISFET) biosensor. SEF is directly collected by a weak evacuation through skin from which the stratum corneum has been removed. An SEF collecting cell with a stainless-steel mesh at the bottom is kept in a weak vacuum condition, and SEF is sucked up through the mesh and deposited in a reservoir above. An ISFET glucose sensor is able to detect glucose concentrations in very small SEF samples through the use of two small ISFETs and an immobilised enzyme membrane. The reliability of transcutaneously obtained SEF was first confirmed in an experiment using rabbits. A clinical analyser was used to determine levels of glucose, urea nitrogen and creatinine in SEF obtained transcutaneously; these results are compared with results obtained by the same analyser directly from sera. The ISFET glucose sensor was successfully tested on human subjects for the monitoring of blood glucose levels. During these tests, glucose level changes in the SEF followed actual blood glucose level changes with a slight time delay. Results suggest the feasibility of non-invasive, transcutaneous monitoring of low molecular weight substances in the blood without the use of ordinary blood sampling.

PROFESSIONAL FLASH CONTINUOUS GLUCOSE MONITORING WITH AMBULATORY GLUCOSE PROFILE REPORTING TO SUPPLEMENT A1C: RATIONALE AND PRACTICAL IMPLEMENTATION.

PubMed

Hirsch, Irl B; Verderese, Carol A

2017-11-01

Recent consensus statements strongly advocate downloading and interpreting continuous glucose data for diabetes management in patients with type 1 or 2 diabetes. Supplementing periodic glycated hemoglobin (A1C) testing with intermittent continuous glucose monitoring (CGM) using a standardized report form known as the ambulatory glucose profile (AGP) is an evolving standard of care. The rationale for this approach and its implementation with a recently approved novel monitoring technology are explored. Search of the medical literature, professional guidelines, and real-world evidence guided this introduction of an integrative practice framework that uses AGP in conjunction with intermittent flash continuous glucose monitoring (FCGM) as a supplement to A1C testing. The combination of intermittent continuous glucose pattern analysis, standardized glucose metrics, and a readily interpretable data report has the potential to practically extend the recognized benefits of CGM to more patients and clarify the relationship between A1C and average glucose levels in individual cases. Novel FCGM technologies portend greater use of continuous forms of glucose monitoring and wider adoption of AGP report analysis. Additional formal and empirical evidence is needed to more fully characterize best practice. A1C = glycated hemoglobin; AGP = ambulatory glucose profile; CGM = continuous glucose monitoring; FCGM = flash continuous glucose monitoring; IQR = interquartile range; SMBG = self-monitoring of blood glucose.

Blood Glucose Monitoring Before and After Type 1 Diabetes Clinic Visits.

PubMed

Driscoll, Kimberly A; Johnson, Suzanne Bennett; Wang, Yuxia; Wright, Nancy; Deeb, Larry C

2017-12-23

To determine patterns of blood glucose monitoring in children and adolescents with type 1 diabetes (T1D) before and after routine T1D clinic visits. Blood glucose monitoring data were downloaded at four consecutive routine clinic visits from children and adolescents aged 5-18 years. Linear mixed models were used to analyze patterns of blood glucose monitoring in patients who had at least 28 days of data stored in their blood glucose monitors. In general, the frequency of blood glucose monitoring decreased across visits, and younger children engaged in more frequent blood glucose monitoring. Blood glucose monitoring increased before the T1D clinic visits in younger children, but not in adolescents. It declined after the visit regardless of age. Members of the T1D care team need to consider that a T1D clinic visit may prompt an increase in blood glucose monitoring when making treatment changes and recommendations. Tailored interventions are needed to maintain that higher level of adherence across time. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Evaluation of Parotid Salivary Glucose Level for Clinical Diagnosis and Monitoring Type 2 Diabetes Mellitus Patients

PubMed Central

Wang, Beibei; Du, Juan; Zhu, Zhao; Ma, Zhihong; Wang, Songlin

2017-01-01

Background. To investigate the relationships among blood glucose, mixed saliva glucose, and parotid glucose in type 2 diabetes patients and to evaluate the diagnostic and monitoring value of salivary gland glucose in patients with type 2 diabetes (type 2DM). Material and Methods. Thirty patients with type 2DM and 30 healthy age- and sex-matched individuals were included in this study. Glucose levels in unstimulated mixed saliva and in unstimulated parotid saliva were measured by the glucose oxidase peroxidase method. Results. The blood glucose and parotid salivary glucose levels in type 2DM patients were significantly higher than those in the controls (P < 0.05). The blood glucose, parotid salivary glucose, and mixed salivary glucose were 7.46 ± 1.44 mmol/L, 0.18 ± 0.19 mmol/L, and 3.17 × 10−2 ± 2.84 × 10−2 mmol/L, respectively, in the type 2DM group; the corresponding glucose levels in the control group were 5.56 ± 0.71 mmol/L, 7.70 × 10−2 ± 6.02 × 10−2 mmol/L, and 3.47 × 10−2 ± 2.79 × 10−2 mmol/L. The parotid salivary and blood glucose levels in type 2DM patients were strongly correlated; the linear regression equation for blood glucose and parotid salivary glucose was Y = 6.267X + 6.360, with r = 0.810. However, mixed salivary glucose levels were not significantly different in the type 2 diabetes group compared with the control group. Conclusion. Our results suggest that parotid salivary glucose has potential as a biomarker to monitor type 2DM and as a painless, noninvasive method for the management of type 2DM. PMID:28251153

Development of a nanowire based titanium needle probe sensor for glucose monitoring

NASA Astrophysics Data System (ADS)

Deshpande, Devesh C.

The need for continuous monitoring of various physiological functions such as blood glucose levels, neural functions and cholesterol levels has fostered the research and development of various schemes of biosensors to sense and help control the respective function. The needs of patients for sensors with minimal discomfort, longer life and better performance have necessitated the development towards smaller and more efficient sensors. In addition, the need for higher functionality from smaller sensors has led to the development of sensors with multiple electrodes, each electrode capable of sensing a different body function. Such multi-electrode sensors need to be fabricated using micro-fabrication processes in order to achieve precise control over the size, shape and placement of the electrodes. Multielectrode sensors fabricated using silicon and polymers have been demonstrated. One physiological function that attracts widespread interest is continuous glucose monitoring in our blood, since Diabetes affects millions of people all over the world. Significant deviations of blood glucose levels from the normal levels of 4-8 mM can cause fainting, coma and damage to the eyes, kidneys, nerves and blood vessels. For chronic patients, continuous monitoring of glucose levels is essential for accurate and timely treatment. A few continuous monitoring sensors are available in the market, but they have problems and cannot replace the strip type one-time glucose monitoring systems as yet. To address this need, large scale research efforts have been targeted towards continuous monitoring. The demand for higher accuracy and sensitivity has motivated researchers to evaluate the use of nanostructures in sensing. The large surface area-to-volume ratio of such structures could enable further miniaturization and push the detection limits, potentially enabling even single molecule detection. This research involved the development of a biocompatible titanium needle probe sensor for glucose monitoring. The working electrode of the sensor comprised of vertically aligned, free standing Au nanowires to utilize the advantages of nanostructures. The sensor was fabricated on biocompatible titanium substrate using Micro/Nano fabrication processes such as Plasma Enhanced Chemical Vapor Deposition (PECVD), Electron Beam Evaporation, Lithography, aligned nanowire growth and wet and plasma etching. Arrays of free-standing nanowires were grown at room temperature and pressure using a novel template based growth process. After fabrication of the sensor, immobilization of an enzyme was carried out on the sensing electrode to ensure selectivity of the sensor to glucose. This was achieved by using self-assembled thiol monolayers and entrapment in a conducting polymer matrix. Glucose oxidase was used for this purpose, which catalyzed the conversion of glucose to gluconic acid, producing hydrogen peroxide in the process. Amperometry was used for glucose detection, in which a constant voltage was applied to the sensor. This potential oxidized the hydrogen peroxide and produced changes in the current which were correlated to the glucose concentration. This dissertation will address the importance of continuous glucose monitoring, current technology and problems faced, the design and fabrication of the sensor and electrochemical sensing to detect glucose levels in solution. Finally, the problems encountered during the process will be discussed and the future work will be detailed.

[Recent advances of monitoring and glycaemia control during early postoperative period in patients after pancreas surgery].

PubMed

Lishova, E A; Nikoda, V V; Bondarenko, A V; Ragozin, A K; Skipenko, O G

2013-01-01

Recently new technologies of diagnostics and correction of carbohydrates metabolism disturbances are introduced in the ICU to improve the safety for patients during intensive care. 33 patients after pancreas surgery were included into the study 13 patients (39%) had underlying diabetes mellitus. Glucose level changes in the interstitial liquid of the subcutaneous fat during postoperative period were monitored by system of CGM Medtronic MiniMed Guardian RT, MiniMed Paradigm Real-time. Valid values of glucose were from 4.1 to 10.1 mmol/L. Episodes of glucose level increasing occurred in 94% of patients in postoperative period after pancreas surgery. Average level of glucose was within the limits of valid values. However in 64% of cases patients needed insulin therapy Used systems of continuous glucose monitoring in the ICU allow improving the safety for patients receiving artificial nutrition and intravenous insulin therapy.

Validation of the continuous glucose monitoring sensor in preterm infants.

PubMed

Beardsall, K; Vanhaesebrouck, S; Ogilvy-Stuart, A L; Vanhole, C; VanWeissenbruch, M; Midgley, P; Thio, M; Cornette, L; Ossuetta, I; Palmer, C R; Iglesias, I; de Jong, M; Gill, B; de Zegher, F; Dunger, D B

2013-03-01

Recent studies have highlighted the need for improved methods of monitoring glucose control in intensive care to reduce hyperglycaemia, without increasing the risk of hypoglycaemia. Continuous glucose monitoring is increasingly used in children with diabetes, but there are little data regarding its use in the preterm infant, particularly at extremes of glucose levels and over prolonged periods. This study aimed to assess the accuracy of the continuous glucose monitoring sensor (CGMS) across the glucose profile, and to determine whether there was any deterioration over a 7 day period. Prospectively collected CGMS data from the NIRTURE Trial was compared with the data obtained simultaneously using point of care glucose monitors. An international multicentre randomised controlled trial. One hundred and eighty-eight very low birth weight control infants. Optimal accuracy, performance goals (American Diabetes Association consensus), Bland Altman, Error Grid analyses and accuracy. The mean (SD) duration of CGMS recordings was 156.18 (29) h (6.5 days), with a total of 5207 paired glucose levels. CGMS data correlated well with point of care devices (r=0.94), with minimal bias. It met the Clarke Error Grid and Consensus Grid criteria for clinical significance. Accuracy of single readings to detect set thresholds of hypoglycaemia, or hyperglycaemia was poor. There was no deterioration over time from insertion. CGMS can provide information on trends in glucose control, and guidance on the need for blood glucose assessment. This highlights the potential use of CGMS in optimising glucose control in preterm infants.

Skin-like biosensor system via electrochemical channels for noninvasive blood glucose monitoring.

PubMed

Chen, Yihao; Lu, Siyuan; Zhang, Shasha; Li, Yan; Qu, Zhe; Chen, Ying; Lu, Bingwei; Wang, Xinyan; Feng, Xue

2017-12-01

Currently, noninvasive glucose monitoring is not widely appreciated because of its uncertain measurement accuracy, weak blood glucose correlation, and inability to detect hyperglycemia/hypoglycemia during sleep. We present a strategy to design and fabricate a skin-like biosensor system for noninvasive, in situ, and highly accurate intravascular blood glucose monitoring. The system integrates an ultrathin skin-like biosensor with paper battery-powered electrochemical twin channels (ETCs). The designed subcutaneous ETCs drive intravascular blood glucose out of the vessel and transport it to the skin surface. The ultrathin (~3 μm) nanostructured biosensor, with high sensitivity (130.4 μA/mM), fully absorbs and measures the glucose, owing to its extreme conformability. We conducted in vivo human clinical trials. The noninvasive measurement results for intravascular blood glucose showed a high correlation (>0.9) with clinically measured blood glucose levels. The system opens up new prospects for clinical-grade noninvasive continuous glucose monitoring.

Skin-like biosensor system via electrochemical channels for noninvasive blood glucose monitoring

PubMed Central

Chen, Yihao; Lu, Siyuan; Zhang, Shasha; Li, Yan; Qu, Zhe; Chen, Ying; Lu, Bingwei; Wang, Xinyan; Feng, Xue

2017-01-01

Currently, noninvasive glucose monitoring is not widely appreciated because of its uncertain measurement accuracy, weak blood glucose correlation, and inability to detect hyperglycemia/hypoglycemia during sleep. We present a strategy to design and fabricate a skin-like biosensor system for noninvasive, in situ, and highly accurate intravascular blood glucose monitoring. The system integrates an ultrathin skin-like biosensor with paper battery–powered electrochemical twin channels (ETCs). The designed subcutaneous ETCs drive intravascular blood glucose out of the vessel and transport it to the skin surface. The ultrathin (~3 μm) nanostructured biosensor, with high sensitivity (130.4 μA/mM), fully absorbs and measures the glucose, owing to its extreme conformability. We conducted in vivo human clinical trials. The noninvasive measurement results for intravascular blood glucose showed a high correlation (>0.9) with clinically measured blood glucose levels. The system opens up new prospects for clinical-grade noninvasive continuous glucose monitoring. PMID:29279864

Evaluation of three glucometers for whole blood glucose measurements at the point of care in preterm or low-birth-weight infants.

PubMed

Hwang, Joon Ho; Sohn, Yong-Hak; Chang, Seong-Sil; Kim, Seung Yeon

2015-08-01

We evaluated three blood glucose self-monitoring for measuring whole blood glucose levels in preterm and low-birth-weight infants. Between December 1, 2012 and March 31, 2013, 230 blood samples were collected from 50 newborns, who weighed, ≤2,300 g or were ≤36 weeks old, in the the neonatal intensive care unit of Eulji University Hospital. Three blood glucose self-monitoring (A: Precision Pcx, Abbott; B: One-Touch Verio, Johnson & Johnson; C: LifeScan SureStep Flexx, Johnson & Johnson) were used for the blood glucose measurements. The results were compared to those obtained using laboratory equipment (D: Advia chemical analyzer, Siemens Healthcare Diagnostics Inc.). The correlation coefficients between laboratory equipment and the three blood glucose self-monitoring (A, B, and C) were found to be 0.888, 0.884, and 0.900, respectively. For glucose levels≤60 mg/dL, the correlation coefficients were 0.674, 0.687, and 0.679, respectively. For glucose levels>60 mg/dL, the correlation coefficients were 0.822, 0.819, and 0.839, respectively. All correlation coefficients were statistically significant. And the values from the blood glucose self-monitoring were not significantly different from the value of the laboratory equipment , after correcting for each device's average value (P>0.05). When using laboratory equipment (blood glucose ≤60 mg/dL), each device had a sensitivity of 0.458, 0.604, and 0.688 and a specificity of 0.995, 0.989, and 0.989, respectively. Significant difference is not found between three blood glucose self-monitoring and laboratory equipment. But correlation between the measured values from blood glucose self-monitoring and laboratory equipment is lower in preterm or low-birth-weight infants than adults.

Mean Levels and Variability in Affect, Diabetes Self-Care Behaviors, and Continuously Monitored Glucose: A Daily Study of Latinos With Type 2 Diabetes.

PubMed

Wagner, Julie; Armeli, Stephen; Tennen, Howard; Bermudez-Millan, Angela; Wolpert, Howard; Pérez-Escamilla, Rafael

2017-09-01

This study investigated between- and within-person associations among mean levels and variability in affect, diabetes self-care behaviors, and continuously monitored glucose in Latinos with type 2 diabetes. Fifty participants (M [SD] age = 57.8 [11.7] years, 74% women, mean [SD] glycosylated hemoglobin A1c = 8.3% [1.5%]) wore a "blinded" continuous glucose monitor for 7 days, and they responded to twice daily automated phone surveys regarding positive affect, negative affect, and self-care behaviors. Higher mean levels of NA were associated with higher mean glucose (r = .30), greater percent hyperglycemia (r = .34) and greater percentage of out-of-range glucose (r = .34). Higher NA variability was also related to higher mean glucose (r = .34), greater percent of hyperglycemia (r = .44) and greater percentage of out-of-range glucose (r = .43). Higher positive affect variability was related to lower percentage of hypoglycemia (r = -.33). Higher mean levels of self-care behaviors were related to lower glucose variability (r = -.35). Finally, higher self-care behavior variability was related to greater percentage of hyperglycemia (r = .31) and greater percentage of out-of-range glucose (r = -.28). In multilevel regression models, within-person increases from mean levels of self-care were associated with lower mean levels of glucose (b = -7.4, 95% confidence interval [CI] = -12.8 to -1.9), lower percentage of hyperglycemia (b = -0.04, 95% CI = -0.07 to -0.01), and higher percentage of hypoglycemia (b = 0.02, 95% CI = 0.01 to 0.03) in the subsequent 10-hour period. Near-to-real time sampling documented associations of glucose with affect and diabetes self-care that are not detectable with traditional measures.

Glucose metabolism disorder in obese children assessed by continuous glucose monitoring system.

PubMed

Zou, Chao-Chun; Liang, Li; Hong, Fang; Zhao, Zheng-Yan

2008-02-01

Continuous glucose monitoring system (CGMS) can measure glucose levels at 5-minute intervals over a few days, and may be used to detect hypoglycemia, guide insulin therapy, and control glucose levels. This study was undertaken to assess the glucose metabolism disorder by CGMS in obese children. Eighty-four obese children were studied. Interstitial fluid (ISF) glucose levels were measured by CGMS for 24 hours covering the time for oral glucose tolerance test (OGTT). Impaired glucose tolerance (IGT), impaired fasting glucose (IFG), type 2 diabetic mellitus (T2DM) and hypoglycemia were assessed by CGMS. Five children failed to complete CGMS test. The glucose levels in ISF measured by CGMS were highly correlated with those in capillary samples (r=0.775, P<0.001). However, the correlation between ISF and capillary glucose levels was lower during the first hour than that in the later time period (r=0.722 vs r=0.830), and the ISF glucose levels in 69.62% of children were higher than baseline levels in the initial 1-3 hours. In 79 obese children who finished the CGMS, 2 children had IFG, 2 had IGT, 3 had IFG + IGT, and 2 had T2DM. Nocturnal hypoglycemia was noted during the overnight fasting in 11 children (13.92%). Our data suggest that glucose metabolism disorder including hyperglycemia and hypoglycemia is very common in obese children. Further studies are required to improve the precision of the CGMS in children.

Impact of Ramadan fasting on glucose levels in women with gestational diabetes mellitus treated with diet alone or diet plus metformin: a continuous glucose monitoring study.

PubMed

Afandi, Bachar O; Hassanein, Mohamed M; Majd, Lina M; Nagelkerke, Nico J D

2017-01-01

Women with gestational diabetes mellitus (GDM) are categorized as at high risk for adverse events during Ramadan fasting. However, this is largely based on clinical opinion. In this study, we shed some light on what happens to glucose levels during Ramadan fasting. This is a prospective observational study. A total of 32 patients with GDM were recruited; 10 patients, treated with diet only (group 1), to observe their glucose levels before fasting and 22 patients who insisted on fasting the month of Ramadan, 13 treated with diet only (group 2) and nine treated with diet plus metformin 500 mg twice daily (group 3), to evaluate their glucose levels during fasting. Interstitial glucose was monitored in all by using the iPro2 Professional continuous glucose monitoring (CGM) system. Mean glucose level was 116±21 mg/dL (6.16±1.16 mmol/L), 106±9 mg/dL (5.88±0.49 mmol/L) and 99±7 mg/dL (5.49±0.34 mmol/L) in groups 1, 2 and 3, respectively. Patients in group 1 had the lowest rate of hypoglycemia (50%), followed by patients in group 2 (60%), whereas patients in group 3 had the highest rate of hypoglycemia (78%). CGM data indicates that Ramadan fasting in women with GDM treated with diet alone or with diet plus metformin was associated with lower mean glucose levels and higher rates of hypoglycemia when compared with non-fasting glucose levels. Women with GDM should be advised against fasting during Ramadan until further data is available.

The Relationship Between a Balanced Time Perspective and Self-monitoring of Blood Glucose Among People With Type 1 Diabetes.

PubMed

Baird, Harriet M; Webb, Thomas L; Martin, Jilly; Sirois, Fuschia M

2018-05-10

Self-monitoring of blood glucose helps people with type 1 diabetes to maintain glycemic control and reduce the risk of complications. However, adherence to blood glucose monitoring is often suboptimal. Like many health behaviors, self-monitoring of blood glucose involves exerting effort in the present to achieve future benefits. As such, the present research explored whether individual differences in time perspective-specifically, the extent to which people have a balanced time perspective-are associated with the frequency with which people with type 1 diabetes monitor their blood glucose and, thus, maintain glycemic control. Adults with type 1 diabetes completed measures of time perspective, feelings associated with monitoring, attitudes toward monitoring, and trait self-control. Objective data regarding the frequency with which participants monitored their blood glucose levels and their long-term glycemic control were extracted from their medical records. Hierarchical regression analyses and tests of indirect effects (N = 129) indicated that having a more balanced time perspective was associated with more frequent monitoring of blood glucose and, as a result, better glycemic control. Further analyses (N = 158) also indicated that there was an indirect relationship between balanced time perspective and monitoring of blood glucose via the feelings that participants associated with monitoring and their subsequent attitudes toward monitoring. These findings point to the importance and relevance of time perspective for understanding health-related behavior and may help to inform interventions designed to promote self-monitoring of blood glucose in people with type 1 diabetes.

The performance of flash glucose monitoring in critically ill patients with diabetes.

PubMed

Ancona, Paolo; Eastwood, Glenn M; Lucchetta, Luca; Ekinci, Elif I; Bellomo, Rinaldo; Mårtensson, Johan

2017-06-01

Frequent glucose monitoring may improve glycaemic control in critically ill patients with diabetes. We aimed to assess the accuracy of a novel subcutaneous flash glucose monitor (FreeStyle Libre [Abbott Diabetes Care]) in these patients. We applied the FreeStyle Libre sensor to the upper arm of eight patients with diabetes in the intensive care unit and obtained hourly flash glucose measurements. Duplicate recordings were obtained to assess test-retest reliability. The reference glucose level was measured in arterial or capillary blood. We determined numerical accuracy using Bland- Altman methods, the mean absolute relative difference (MARD) and whether the International Organization for Standardization (ISO) and Clinical and Laboratory Standards Institute Point of Care Testing (CLSI POCT) criteria were met. Clarke error grid (CEG) and surveillance error grid (SEG) analyses were used to determine clinical accuracy. We compared 484 duplicate flash glucose measurements and observed a Pearson correlation coefficient of 0.97 and a coefficient of repeatability of 1.6 mmol/L. We studied 185 flash readings paired with arterial glucose levels, and 89 paired with capillary glucose levels. Using the arterial glucose level as the reference, we found a mean bias of 1.4 mmol/L (limits of agreement, -1.7 to 4.5 mmol/L). The MARD was 14% (95% CI, 12%-16%) and the proportion of measurements meeting ISO and CLSI POCT criteria was 64.3% and 56.8%, respectively. The proportions of values within a low-risk zone on CEG and SEG analyses were 97.8% and 99.5%, respectively. Using capillary glucose levels as the reference, we found that numerical and clinical accuracy were lower. The subcutaneous FreeStyle Libre blood glucose measurement system showed high test-retest reliability and acceptable accuracy when compared with arterial blood glucose measurement in critically ill patients with diabetes.

A glucose oxidase-coupled DNAzyme sensor for glucose detection in tears and saliva.

PubMed

Liu, Chengcheng; Sheng, Yongjie; Sun, Yanhong; Feng, Junkui; Wang, Shijin; Zhang, Jin; Xu, Jiacui; Jiang, Dazhi

2015-08-15

Biosensors have been widely investigated and utilized in a variety of fields ranging from environmental monitoring to clinical diagnostics. Glucose biosensors have triggered great interest and have been widely exploited since glucose determination is essential for diabetes diagnosis. In here, we designed a novel dual-enzyme biosensor composed of glucose oxidase (GOx) and pistol-like DNAzyme (PLDz) to detect glucose levels in tears and saliva. First, GOx, as a molecular recognition element, catalyzes the oxidation of glucose forming H2O2; then PLDz recognizes the produced H2O2 as a secondary signal and performs a self-cleavage reaction promoted by Mn(2+), Co(2+) and Cu(2+). Thus, detection of glucose could be realized by monitoring the cleavage rate of PLDz. The slope of the cleavage rate of PLDz versus glucose concentration curve was fitted with a Double Boltzmann equation, with a range of glucose from 100 nM to 10mM and a detection limit of 5 μM. We further applied the GOx-PLDz 1.0 biosensor for glucose detection in tears and saliva, glucose levels in which are 720±81 μM and 405±56 μM respectively. Therefore, the GOx-PLDz 1.0 biosensor is able to determine glucose levels in tears and saliva as a noninvasive glucose biosensor, which is important for diabetic patients with frequent/continuous glucose monitoring requirements. In addition, induction of DNAzyme provides a new approach in the development of glucose biosensors. Copyright © 2015 Elsevier B.V. All rights reserved.

Nanosensors and nanomaterials for monitoring glucose in diabetes

PubMed Central

Cash, Kevin J.; Clark, Heather A.

2010-01-01

Worldwide, diabetes is a rapidly growing problem that is managed at the individual level by monitoring and controlling blood glucose levels to minimize the negative effects of the disease. Because of limitations in diagnostic methods, significant research efforts are focused on developing improved methods to measure glucose. Nanotechnology has impacted these efforts by increasing the surface area of sensors, improving the catalytic properties of electrodes and providing nanoscale sensors. Herein, we discuss developments in the past several years on both nanosensors that directly measure glucose as well as nanomaterials that improve glucose sensor function. Finally, we discuss challenges that must be overcome to apply these developments in the clinic. PMID:20869318

Evaluation of a Novel Glucose Area Under the Curve (AUC) Monitoring System: Comparison with the AUC by Continuous Glucose Monitoring

PubMed Central

Maegawa, Hiroshi; Morino, Katsutaro; Nishio, Yoshihiko; Sato, Toshiyuki; Okada, Seiki; Kikkawa, Yasuo; Watanabe, Toshihiro; Nakajima, Hiromu; Kashiwagi, Atsunori

2016-01-01

Background Management of postprandial hyperglycemia is a key aspect in diabetes treatment. We developed a novel system to measure glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET) for simple monitoring of postprandial glucose excursions. In this study, we evaluated the relationship between our system and continuous glucose monitoring (CGM) by comparing glucose AUC obtained using MIET with that obtained using CGM for a long duration. Methods Twenty diabetic inpatients wearing a CGM system were enrolled. For MIET measurement, a plastic microneedle array was applied to the skin as pretreatment, and hydrogels were placed on the pretreated area to collect interstitial fluid. Hydrogels were replaced every 2 or 4 hours and AUC was predicted on the basis of glucose and sodium ion levels. Results AUC predicted by MIET correlated well with that measured by CGM (r=0.93). Good performances of both consecutive 2- and 4-hour measurements were observed (measurement error: 11.7%±10.2% for 2 hours and 11.1%±7.9% for 4 hours), indicating the possibility of repetitive measurements up to 8 hours. The influence of neither glucose fluctuation nor average glucose level over the measurement accuracy was observed through 8 hours. Conclusion Our system showed good relationship with AUC values from CGM up to 8 hours, indicating that single pretreatment can cover a large portion of glucose excursion in a day. These results indicated possibility of our system to contribute to convenient monitoring of glucose excursions for a long duration. PMID:27535643

Evaluation of a Novel Glucose Area Under the Curve (AUC) Monitoring System: Comparison with the AUC by Continuous Glucose Monitoring.

PubMed

Ugi, Satoshi; Maegawa, Hiroshi; Morino, Katsutaro; Nishio, Yoshihiko; Sato, Toshiyuki; Okada, Seiki; Kikkawa, Yasuo; Watanabe, Toshihiro; Nakajima, Hiromu; Kashiwagi, Atsunori

2016-08-01

Management of postprandial hyperglycemia is a key aspect in diabetes treatment. We developed a novel system to measure glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET) for simple monitoring of postprandial glucose excursions. In this study, we evaluated the relationship between our system and continuous glucose monitoring (CGM) by comparing glucose AUC obtained using MIET with that obtained using CGM for a long duration. Twenty diabetic inpatients wearing a CGM system were enrolled. For MIET measurement, a plastic microneedle array was applied to the skin as pretreatment, and hydrogels were placed on the pretreated area to collect interstitial fluid. Hydrogels were replaced every 2 or 4 hours and AUC was predicted on the basis of glucose and sodium ion levels. AUC predicted by MIET correlated well with that measured by CGM (r=0.93). Good performances of both consecutive 2- and 4-hour measurements were observed (measurement error: 11.7%±10.2% for 2 hours and 11.1%±7.9% for 4 hours), indicating the possibility of repetitive measurements up to 8 hours. The influence of neither glucose fluctuation nor average glucose level over the measurement accuracy was observed through 8 hours. Our system showed good relationship with AUC values from CGM up to 8 hours, indicating that single pretreatment can cover a large portion of glucose excursion in a day. These results indicated possibility of our system to contribute to convenient monitoring of glucose excursions for a long duration.

Nocturnal hypoglycemia identified by a continuous glucose monitoring system in patients with primary adrenal insufficiency (Addison's Disease).

PubMed

Meyer, Gesine; Hackemann, Annika; Reusch, Juergen; Badenhoop, Klaus

2012-05-01

Hypoglycemia can be a symptom in patients with Addison's disease. The common regimen of replacement therapy with oral glucocorticoids results in unphysiological low cortisol levels in the early morning, the time of highest insulin sensitivity. Therefore patients with Addison's disease are at risk for unrecognized and potentially severe nocturnal hypoglycemia also because of a disturbed counterregulatory function. Use of a continuous glucose monitoring system (CGMS) could help to adjust hydrocortisone treatment and to avoid nocturnal hypoglycemia in these patients. Thirteen patients with Addison's disease were screened for hypoglycemia wearing a CGMS for 3-5 days. In one patient we identified a hypoglycemic episode at 3:45 a.m. with a blood glucose level of 46 mg/dL, clearly beneath the 95% tolerance interval of minimal glucose levels between 2 and 4 a.m. (53.84 mg/dL). After the hydrocortisone replacement scheme was changed, the minimum blood glucose level between 2 and 4 a.m. normalized to 87 mg/dL. Continuous glucose monitoring can detect nocturnal hypoglycemia in patients with primary adrenal insufficiency and hence prevent in these patients an impaired quality of life and even serious adverse effects.

Noninvasive diagnostic devices for diabetes through measuring tear glucose.

PubMed

Zhang, Jin; Hodge, William; Hutnick, Cindy; Wang, Xianbin

2011-01-01

This article reviews the development of a noninvasive diagnostic for diabetes by detecting ocular glucose. Early diagnosis and daily management are very important to diabetes patients to ensure a healthy life. Commercial blood glucose sensors have been used since the 1970s. Millions of diabetes patients have to prick their finger for a drop of blood 4-5 times a day to check blood glucose levels--almost 1800 times annually. There is a strong need to have a noninvasive device to help patients to manage the disease easily and painlessly. Instead of detecting the glucose in blood, monitoring the glucose level in other body fluids may provide a feasible approach for noninvasive diagnosis and diabetes control. Tear glucose has been studied for several decades. This article reviews studies on ocular glucose and its monitoring methods. Attempts to continuously monitor the concentration of tear glucose by using contact lens-based sensors are discussed as well as our current development of a nanostructured lens-based sensor for diabetes. This disposable biosensor for the detection of tear glucose may provide an alternative method to help patients manage the disease conveniently. © 2010 Diabetes Technology Society.

Glucose control and use of continuous glucose monitoring in the intensive care unit: a critical review.

PubMed

De Block, Christophe; Manuel-y-Keenoy, Begoña; Rogiers, Peter; Jorens, Philippe; Van Gaal, Luc

2008-08-01

Stress hyperglycemia recently became a major therapeutic target in the Intensive Care Unit (ICU) since it occurs in most critically ill patients and is associated with adverse outcome, including increased mortality. Intensive insulin therapy to achieve normoglycemia may reduce mortality, morbidity and the length of ICU and in-hospital stay. However, obtaining normoglycemia requires extensive efforts from the medical staff, including frequent glucose monitoring and adjustment of insulin dose. Current insulin titration is based upon discrete glucose measurements, which may miss fast changes in glycemia and which does not give a full picture of overall glycemic control. Recent evidence suggests that continuous monitoring of glucose levels may help to signal glycemic excursions and eventually to optimize insulin titration in the ICU. In this review we will summarise monitoring and treatment strategies to achieve normoglycemia in the ICU, with special emphasis on the possible advantages of continuous glucose monitoring.

Application of optical lens of a CD writer for detecting the blood glucose semi-invasively

NASA Astrophysics Data System (ADS)

Meshram, N. D.; Dahikar, P. B.

2014-10-01

Recent technological advancements in the photonics industry have led to a resurgence of interest in optical glucose sensing and to realistic progress toward the development of an optical glucose sensor. Such a sensor has the potential to significantly improve the quality of life for the estimated 16 million diabetics in this country by making routine glucose measurements more convenient. Currently over 100 small companies and universities are working to develop noninvasive or minimally invasive glucose sensing technologies, and optical methods play a large role in these efforts. It has become overwhelmingly clear that frequent monitoring and tight control of blood sugar levels are requisite for effective management of Diabetes mellitus and reduction of the complications associated with this disease. The pain and trouble associated with current "finger-stick" methods for blood glucose monitoring result in decreased patient compliance and a failure to control blood sugar levels. Thus, the development of a convenient noninvasive blood glucose monitor holds the potential to significantly reduce the morbidity and mortality associated with Diabetes. A method and apparatus for noninvasive measurement of blood glucose concentration based on transilluminated laser beam via the Index Finger has been reported in this paper. This method depends on photodiode based laser operating at 632.8 nm wavelength. During measurement, the index finger is inserted into the glucose sensing unit, the transilluminated optical signal is converted into an electrical signal, compared with the reference electrical signal, and the obtained difference signal is processed by signal processing unit which presents the results in the form of blood glucose concentration. This method would enable the monitoring blood glucose level of the diabetic patient continuously, safely and noninvasively..

Application of optical lens of a CD writer for detecting the blood glucose semi-invasively

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meshram, N. D., E-mail: meshramnileshsd@gmail.com; Dahikar, P. B., E-mail: pbdahikar@rediffmail.com

Recent technological advancements in the photonics industry have led to a resurgence of interest in optical glucose sensing and to realistic progress toward the development of an optical glucose sensor. Such a sensor has the potential to significantly improve the quality of life for the estimated 16 million diabetics in this country by making routine glucose measurements more convenient. Currently over 100 small companies and universities are working to develop noninvasive or minimally invasive glucose sensing technologies, and optical methods play a large role in these efforts. It has become overwhelmingly clear that frequent monitoring and tight control of bloodmore » sugar levels are requisite for effective management of Diabetes mellitus and reduction of the complications associated with this disease. The pain and trouble associated with current “finger-stick” methods for blood glucose monitoring result in decreased patient compliance and a failure to control blood sugar levels. Thus, the development of a convenient noninvasive blood glucose monitor holds the potential to significantly reduce the morbidity and mortality associated with Diabetes. A method and apparatus for noninvasive measurement of blood glucose concentration based on transilluminated laser beam via the Index Finger has been reported in this paper. This method depends on photodiode based laser operating at 632.8 nm wavelength. During measurement, the index finger is inserted into the glucose sensing unit, the transilluminated optical signal is converted into an electrical signal, compared with the reference electrical signal, and the obtained difference signal is processed by signal processing unit which presents the results in the form of blood glucose concentration. This method would enable the monitoring blood glucose level of the diabetic patient continuously, safely and noninvasively.« less

Nano-Engineered Biomimetic Optical Sensors for Glucose Monitoring in Diabetes.

PubMed

Rauf, Sajid; Hayat Nawaz, Muhammad Azhar; Badea, Mihaela; Marty, Jean Louis; Hayat, Akhtar

2016-11-17

Diabetes is a rapidly growing disease that can be monitored at an individual level by controlling the blood glucose level, hence minimizing the negative impact of the disease. Significant research efforts have been focused on the design of novel and improved technologies to overcome the limitations of existing glucose analysis methods. In this context, nanotechnology has enabled the diagnosis at the single cell and molecular level with the possibility of incorporation in advanced molecular diagnostic biochips. Recent years have witnessed the exploration and synthesis of various types of nanomaterials with enzyme-like properties, with their subsequent integration into the design of biomimetic optical sensors for glucose monitoring. This review paper will provide insights on the type, nature and synthesis of different biomimetic nanomaterials. Moreover, recent developments in the integration of these nanomaterials for optical glucose biosensing will be highlighted, with a final discussion on the challenges that must be addressed for successful implementation of these nano-devices in the clinical applications is presented.

Nano-Engineered Biomimetic Optical Sensors for Glucose Monitoring in Diabetes

PubMed Central

Rauf, Sajid; Hayat Nawaz, Muhammad Azhar; Badea, Mihaela; Marty, Jean Louis; Hayat, Akhtar

2016-01-01

Diabetes is a rapidly growing disease that can be monitored at an individual level by controlling the blood glucose level, hence minimizing the negative impact of the disease. Significant research efforts have been focused on the design of novel and improved technologies to overcome the limitations of existing glucose analysis methods. In this context, nanotechnology has enabled the diagnosis at the single cell and molecular level with the possibility of incorporation in advanced molecular diagnostic biochips. Recent years have witnessed the exploration and synthesis of various types of nanomaterials with enzyme-like properties, with their subsequent integration into the design of biomimetic optical sensors for glucose monitoring. This review paper will provide insights on the type, nature and synthesis of different biomimetic nanomaterials. Moreover, recent developments in the integration of these nanomaterials for optical glucose biosensing will be highlighted, with a final discussion on the challenges that must be addressed for successful implementation of these nano-devices in the clinical applications is presented. PMID:27869658

Enzymatic glucose sensor compensation for variations in ambient oxygen concentration

NASA Astrophysics Data System (ADS)

Collier, Bradley B.; McShane, Michael J.

2013-02-01

Due to the increasing prevalence of diabetes, research toward painless glucose sensing continues. Oxygen sensitive phosphors with glucose oxidase (GOx) can be used to determine glucose levels indirectly by monitoring oxygen consumption. This is an attractive combination because of its speed and specificity. Packaging these molecules together in "smart materials" for implantation will enable non-invasive glucose monitoring. As glucose levels increase, oxygen levels decrease; consequently, the luminescence intensity and lifetime of the phosphor increase. Although the response of the sensor is dependent on glucose concentration, the ambient oxygen concentration also plays a key role. This could lead to inaccurate glucose readings and increase the risk of hyper- or hypoglycemia. To mitigate this risk, the dependence of hydrogel glucose sensor response on oxygen levels was investigated and compensation methods explored. Sensors were calibrated at different oxygen concentrations using a single generic logistic equation, such that trends in oxygen-dependence were determined as varying parameters in the equation. Each parameter was found to be a function of oxygen concentration, such that the correct glucose calibration equation can be calculated if the oxygen level is known. Accuracy of compensation will be determined by developing an overall calibration, using both glucose and oxygen sensors in parallel, correcting for oxygen fluctuations in real time by intentionally varying oxygen, and calculating the error in actual and predicted glucose levels. While this method was developed for compensation of enzymatic glucose sensors, in principle it can also be implemented with other kinds of sensors utilizing oxidases.

Nanosensors and nanomaterials for monitoring glucose in diabetes.

PubMed

Cash, Kevin J; Clark, Heather A

2010-12-01

Worldwide, diabetes is a rapidly growing problem that is managed at the individual level by monitoring and controlling blood glucose levels to minimize the negative effects of the disease. Because of limitations in diagnostic methods, significant research efforts are focused on developing improved methods to measure glucose. Nanotechnology has impacted these efforts by increasing the surface area of sensors, improving the catalytic properties of electrodes and providing nanoscale sensors. Here, we discuss developments in the past several years on both nanosensors that directly measure glucose and nanomaterials that improve glucose sensor function. Finally, we discuss challenges that must be overcome to apply these developments in the clinic. Copyright © 2010 Elsevier Ltd. All rights reserved.

Predictive Monitoring for Improved Management of Glucose Levels

PubMed Central

Reifman, Jaques; Rajaraman, Srinivasan; Gribok, Andrei; Ward, W. Kenneth

2007-01-01

Background Recent developments and expected near-future improvements in continuous glucose monitoring (CGM) devices provide opportunities to couple them with mathematical forecasting models to produce predictive monitoring systems for early, proactive glycemia management of diabetes mellitus patients before glucose levels drift to undesirable levels. This article assesses the feasibility of data-driven models to serve as the forecasting engine of predictive monitoring systems. Methods We investigated the capabilities of data-driven autoregressive (AR) models to (1) capture the correlations in glucose time-series data, (2) make accurate predictions as a function of prediction horizon, and (3) be made portable from individual to individual without any need for model tuning. The investigation is performed by employing CGM data from nine type 1 diabetic subjects collected over a continuous 5-day period. Results With CGM data serving as the gold standard, AR model-based predictions of glucose levels assessed over nine subjects with Clarke error grid analysis indicated that, for a 30-minute prediction horizon, individually tuned models yield 97.6 to 100.0% of data in the clinically acceptable zones A and B, whereas cross-subject, portable models yield 95.8 to 99.7% of data in zones A and B. Conclusions This study shows that, for a 30-minute prediction horizon, data-driven AR models provide sufficiently-accurate and clinically-acceptable estimates of glucose levels for timely, proactive therapy and should be considered as the modeling engine for predictive monitoring of patients with type 1 diabetes mellitus. It also suggests that AR models can be made portable from individual to individual with minor performance penalties, while greatly reducing the burden associated with model tuning and data collection for model development. PMID:19885110

Health State Utilities Associated with Glucose Monitoring Devices.

PubMed

Matza, Louis S; Stewart, Katie D; Davies, Evan W; Hellmund, Richard; Polonsky, William H; Kerr, David

2017-03-01

Glucose monitoring is important for patients with diabetes treated with insulin. Conventional glucose monitoring requires a blood sample, typically obtained by pricking the finger. A new sensor-based system called "flash glucose monitoring" monitors glucose levels with a sensor worn on the arm, without requiring blood samples. To estimate the utility difference between these two glucose monitoring approaches for use in cost-utility models. In time trade-off interviews, general population participants in the United Kingdom (London and Edinburgh) valued health states that were drafted and refined on the basis of literature, clinician input, and a pilot study. The health states had identical descriptions of diabetes and insulin treatment, differing only in glucose monitoring approach. A total of 209 participants completed the interviews (51.7% women; mean age = 42.1 years). Mean utilities were 0.851 ± 0.140 for conventional monitoring and 0.882 ± 0.121 for flash monitoring (significant difference between the mean utilities; t = 8.3; P < 0.0001). Of the 209 participants, 78 (37.3%) had a higher utility for flash monitoring, 2 (1.0%) had a higher utility for conventional monitoring, and 129 (61.7%) had the same utility for both health states. The flash glucose monitoring system was associated with a significantly greater utility than the conventional monitoring system. This difference may be useful in cost-utility models comparing the value of glucose monitoring devices for patients with diabetes. This study adds to the literature on treatment process utilities, suggesting that time trade-off methods may be used to quantify preferences among medical devices. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Analytical and Clinical Performance of Blood Glucose Monitors

PubMed Central

Boren, Suzanne Austin; Clarke, William L.

2010-01-01

Background The objective of this study was to understand the level of performance of blood glucose monitors as assessed in the published literature. Methods Medline from January 2000 to October 2009 and reference lists of included articles were searched to identify eligible studies. Key information was abstracted from eligible studies: blood glucose meters tested, blood sample, meter operators, setting, sample of people (number, diabetes type, age, sex, and race), duration of diabetes, years using a glucose meter, insulin use, recommendations followed, performance evaluation measures, and specific factors affecting the accuracy evaluation of blood glucose monitors. Results Thirty-one articles were included in this review. Articles were categorized as review articles of blood glucose accuracy (6 articles), original studies that reported the performance of blood glucose meters in laboratory settings (14 articles) or clinical settings (9 articles), and simulation studies (2 articles). A variety of performance evaluation measures were used in the studies. The authors did not identify any studies that demonstrated a difference in clinical outcomes. Examples of analytical tools used in the description of accuracy (e.g., correlation coefficient, linear regression equations, and International Organization for Standardization standards) and how these traditional measures can complicate the achievement of target blood glucose levels for the patient were presented. The benefits of using error grid analysis to quantify the clinical accuracy of patient-determined blood glucose values were discussed. Conclusions When examining blood glucose monitor performance in the real world, it is important to consider if an improvement in analytical accuracy would lead to improved clinical outcomes for patients. There are several examples of how analytical tools used in the description of self-monitoring of blood glucose accuracy could be irrelevant to treatment decisions. PMID:20167171

Non-invasive, transdermal, path-selective and specific glucose monitoring via a graphene-based platform

NASA Astrophysics Data System (ADS)

Lipani, Luca; Dupont, Bertrand G. R.; Doungmene, Floriant; Marken, Frank; Tyrrell, Rex M.; Guy, Richard H.; Ilie, Adelina

2018-06-01

Currently, there is no available needle-free approach for diabetics to monitor glucose levels in the interstitial fluid. Here, we report a path-selective, non-invasive, transdermal glucose monitoring system based on a miniaturized pixel array platform (realized either by graphene-based thin-film technology, or screen-printing). The system samples glucose from the interstitial fluid via electroosmotic extraction through individual, privileged, follicular pathways in the skin, accessible via the pixels of the array. A proof of principle using mammalian skin ex vivo is demonstrated for specific and `quantized' glucose extraction/detection via follicular pathways, and across the hypo- to hyper-glycaemic range in humans. Furthermore, the quantification of follicular and non-follicular glucose extraction fluxes is clearly shown. In vivo continuous monitoring of interstitial fluid-borne glucose with the pixel array was able to track blood sugar in healthy human subjects. This approach paves the way to clinically relevant glucose detection in diabetics without the need for invasive, finger-stick blood sampling.

Nocturnal Hypoglycemia Identified by a Continuous Glucose Monitoring System in Patients with Primary Adrenal Insufficiency (Addison's Disease)

PubMed Central

Hackemann, Annika; Reusch, Juergen; Badenhoop, Klaus

2012-01-01

Abstract Background Hypoglycemia can be a symptom in patients with Addison's disease. The common regimen of replacement therapy with oral glucocorticoids results in unphysiological low cortisol levels in the early morning, the time of highest insulin sensitivity. Therefore patients with Addison's disease are at risk for unrecognized and potentially severe nocturnal hypoglycemia also because of a disturbed counterregulatory function. Use of a continuous glucose monitoring system (CGMS) could help to adjust hydrocortisone treatment and to avoid nocturnal hypoglycemia in these patients. Methods Thirteen patients with Addison's disease were screened for hypoglycemia wearing a CGMS for 3–5 days. Results In one patient we identified a hypoglycemic episode at 3:45 a.m. with a blood glucose level of 46 mg/dL, clearly beneath the 95% tolerance interval of minimal glucose levels between 2 and 4 a.m. (53.84 mg/dL). After the hydrocortisone replacement scheme was changed, the minimum blood glucose level between 2 and 4 a.m. normalized to 87 mg/dL. Conclusions Continuous glucose monitoring can detect nocturnal hypoglycemia in patients with primary adrenal insufficiency and hence prevent in these patients an impaired quality of life and even serious adverse effects. PMID:22242902

Continuous Glucose Monitoring: Impact on Hypoglycemia.

PubMed

van Beers, Cornelis A J; DeVries, J Hans

2016-11-01

The necessity of strict glycemic control is unquestionable. However, hypoglycemia remains a major limiting factor in achieving satisfactory glucose control, and evidence is mounting to show that hypoglycemia is not benign. Over the past decade, evidence has consistently shown that real-time continuous glucose monitoring improves glycemic control in terms of lowering glycated hemoglobin levels. However, real-time continuous glucose monitoring has not met the expectations of the diabetes community with regard to hypoglycemia prevention. The earlier trials did not demonstrate any effect on either mild or severe hypoglycemia and the effect of real-time continuous glucose monitoring on nocturnal hypoglycemia was often not reported. However, trials specifically designed to reduce hypoglycemia in patients with a high hypoglycemia risk have demonstrated a reduction in hypoglycemia, suggesting that real-time continuous glucose monitoring can prevent hypoglycemia when it is specifically used for that purpose. Moreover, the newest generation of diabetes technology currently available commercially, namely sensor-augmented pump therapy with a (predictive) low glucose suspend feature, has provided more convincing evidence for hypoglycemia prevention. This article provides an overview of the hypoglycemia outcomes of randomized controlled trials that investigate the effect of real-time continuous glucose monitoring alone or sensor-augmented pump therapy with a (predictive) low glucose suspend feature. Furthermore, several possible explanations are provided why trials have not shown a reduction in severe hypoglycemia. In addition, existing evidence is presented of real-time continuous glucose monitoring in patients with impaired awareness of hypoglycemia who have the highest risk of severe hypoglycemia. © 2016 Diabetes Technology Society.

Continuous Glucose Monitoring

PubMed Central

van Beers, Cornelis A. J.; DeVries, J. Hans

2016-01-01

The necessity of strict glycemic control is unquestionable. However, hypoglycemia remains a major limiting factor in achieving satisfactory glucose control, and evidence is mounting to show that hypoglycemia is not benign. Over the past decade, evidence has consistently shown that real-time continuous glucose monitoring improves glycemic control in terms of lowering glycated hemoglobin levels. However, real-time continuous glucose monitoring has not met the expectations of the diabetes community with regard to hypoglycemia prevention. The earlier trials did not demonstrate any effect on either mild or severe hypoglycemia and the effect of real-time continuous glucose monitoring on nocturnal hypoglycemia was often not reported. However, trials specifically designed to reduce hypoglycemia in patients with a high hypoglycemia risk have demonstrated a reduction in hypoglycemia, suggesting that real-time continuous glucose monitoring can prevent hypoglycemia when it is specifically used for that purpose. Moreover, the newest generation of diabetes technology currently available commercially, namely sensor-augmented pump therapy with a (predictive) low glucose suspend feature, has provided more convincing evidence for hypoglycemia prevention. This article provides an overview of the hypoglycemia outcomes of randomized controlled trials that investigate the effect of real-time continuous glucose monitoring alone or sensor-augmented pump therapy with a (predictive) low glucose suspend feature. Furthermore, several possible explanations are provided why trials have not shown a reduction in severe hypoglycemia. In addition, existing evidence is presented of real-time continuous glucose monitoring in patients with impaired awareness of hypoglycemia who have the highest risk of severe hypoglycemia. PMID:27257169

Long-term blood glucose monitoring with implanted telemetry device in conscious and stress-free cynomolgus monkeys.

PubMed

Wang, B; Sun, G; Qiao, W; Liu, Y; Qiao, J; Ye, W; Wang, H; Wang, X; Lindquist, R; Wang, Y; Xiao, Y-F

2017-09-01

Continuous blood glucose monitoring, especially long-term and remote, in diabetic patients or research is very challenging. Nonhuman primate (NHP) is an excellent model for metabolic research, because NHPs can naturally develop Type 2 diabetes mellitus (T2DM) similarly to humans. This study was to investigate blood glucose changes in conscious, moving-free cynomolgus monkeys (Macaca fascicularis) during circadian, meal, stress and drug exposure. Blood glucose, body temperature and physical activities were continuously and simultaneously recorded by implanted HD-XG telemetry device for up to 10 weeks. Blood glucose circadian changes in normoglycemic monkeys significantly differed from that in diabetic animals. Postprandial glucose increase was more obvious after afternoon feeding. Moving a monkey from its housing cage to monkey chair increased blood glucose by 30% in both normoglycemic and diabetic monkeys. Such increase in blood glucose declined to the pre-procedure level in 30 min in normoglycemic animals and >2 h in diabetic monkeys. Oral gavage procedure alone caused hyperglycemia in both normoglycemic and diabetic monkeys. Intravenous injection with the stress hormones, angiotensin II (2 μg/kg) or norepinephrine (0.4 μg/kg), also increased blood glucose level by 30%. The glucose levels measured by the telemetry system correlated significantly well with glucometer readings during glucose tolerance tests (ivGTT or oGTT), insulin tolerance test (ITT), graded glucose infusion (GGI) and clamp. Our data demonstrate that the real-time telemetry method is reliable for monitoring blood glucose remotely and continuously in conscious, stress-free, and moving-free NHPs with the advantages highly valuable to diabetes research and drug discovery.

Disruption in the diabetic device care market

PubMed Central

Mohammed, Raihan

2018-01-01

As diabetes mellitus (DM) has approached pandemic proportions, the pressure for effective glycemic management is mounting. The starting point for managing and living well with DM involves early diagnosis and monitoring blood glucose levels. Therefore, self-monitoring of blood glucose (SMBG) can help patients maintain their blood glucose levels within the appropriate range. The general principle behind the current SMBG method involves a finger prick test to obtain a blood drop, which is applied onto a reagent strip and read by an automated device. Novel techniques are currently under evaluation to create the next generation of painless and accurate glucose monitoring for DM. We began by outlining how the emerging technology of the noninvasive glucose monitoring devices (NIGMDs) provides both economic and clinical benefits for health systems and patients. We further explored the engineering and techniques behind these upcoming devices. Finally, we evaluated how the NIGMDs disrupt the diabetic device care market and drive health care consumerism. We postulated that the NIGMDs play a pivotal role in the implementation of next generation of diabetes prevention strategies. PMID:29440935

Effects of Systemic Metabolic Fuels on Glucose and Lactate Levels in the Brain Extracellular Compartment of the Mouse

PubMed Central

Béland-Millar, Alexandria; Larcher, Jeremy; Courtemanche, Justine; Yuan, Tina; Messier, Claude

2017-01-01

Classic neuroenergetic research has emphasized the role of glucose, its transport and its metabolism in sustaining normal neural function leading to the textbook statement that it is the necessary and sole metabolic fuel of the mammalian brain. New evidence, including the Astrocyte-to-Neuron Lactate Shuttle hypothesis, suggests that the brain can use other metabolic substrates. To further study that possibility, we examined the effect of intraperitoneally administered metabolic fuels (glucose, fructose, lactate, pyruvate, ß-hydroxybutyrate, and galactose), and insulin, on blood, and extracellular brain levels of glucose and lactate in the adult male CD1 mouse. Primary motor cortex extracellular levels of glucose and lactate were monitored in freely moving mice with the use of electrochemical electrodes. Blood concentration of these same metabolites were obtained by tail vein sampling and measured with glucose and lactate meters. Blood and extracellular fluctuations of glucose and lactate were monitored for a 2-h period. We found that the systemic injections of glucose, fructose, lactate, pyruvate, and ß-hydroxybutyrate increased blood lactate levels. Apart for a small transitory rise in brain extracellular lactate levels, the main effect of the systemic injection of glucose, fructose, lactate, pyruvate, and ß-hydroxybutyrate was an increase in brain extracellular glucose levels. Systemic galactose injections produced a small rise in blood glucose and lactate but almost no change in brain extracellular lactate and glucose. Systemic insulin injections led to a decrease in blood glucose and a small rise in blood lactate; however brain extracellular glucose and lactate monotonically decreased at the same rate. Our results support the concept that the brain is able to use alternative fuels and the current experiments suggest some of the mechanisms involved. PMID:28154523

Adaptive Blood Glucose Monitoring and Insulin Measurement Devices for Visually Impaired Persons.

ERIC Educational Resources Information Center

Petzinger, R. A.

1993-01-01

This article describes devices that people with visual impairments and diabetes can use to monitor blood glucose levels and measure insulin. A table lists devices, their manufacturers (including address and telephone number), and comments about the devices. (DB)

Tear glucose detection combining microfluidic thread based device, amperometric biosensor and microflow injection analysis.

PubMed

Agustini, Deonir; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2017-12-15

The tear glucose analysis is an important alternative for the indirect, simple and less invasive monitoring of blood glucose levels. However, the high cost and complex manufacturing process of tear glucose analyzers combined with the need to exchange the sensor after each analysis in the disposable tests prevent widespread application of the tear in glucose monitoring. Here, we present the integration of a biosensor made by the electropolymerization of poly(toluidine blue O) (PTB) and glucose oxidase (GOx) with an electroanalytical microfluidic device of easy assembly based on cotton threads, low cost materials and measurements by microflow injection analysis (µFIA) through passive pumping for performing tear glucose analyses in a simple, rapid and inexpensive way. A high stability between the analyses (RSD = 2.54%) and among the different systems (RSD = 3.13%) was obtained for the determination of glucose, in addition to a wide linear range between 0.075 and 7.5mmolL -1 and a limit of detection of 22.2µmolL -1 . The proposed method was efficiently employed in the determination of tear glucose in non-diabetic volunteers, obtaining a close correlation with their blood glucose levels, simplifying and reducing the costs of the analyses, making the tear glucose monitoring more accessible for the population. Copyright © 2017 Elsevier B.V. All rights reserved.

Blood glucose prediction using neural network

NASA Astrophysics Data System (ADS)

Soh, Chit Siang; Zhang, Xiqin; Chen, Jianhong; Raveendran, P.; Soh, Phey Hong; Yeo, Joon Hock

2008-02-01

We used neural network for blood glucose level determination in this study. The data set used in this study was collected using a non-invasive blood glucose monitoring system with six laser diodes, each laser diode operating at distinct near infrared wavelength between 1500nm and 1800nm. The neural network is specifically used to determine blood glucose level of one individual who participated in an oral glucose tolerance test (OGTT) session. Partial least squares regression is also used for blood glucose level determination for the purpose of comparison with the neural network model. The neural network model performs better in the prediction of blood glucose level as compared with the partial least squares model.

Vitreous Fluid and/or Urine Glucose Concentrations in 1,335 Civil Aviation Accident Pilot Fatalities

DTIC Science & Technology

2008-05-01

glucose, and in those cases wherein glucose levels are elevated, blood hemoglobin A1c ( HbA1c ) is measured. These analyses are conducted to monitor...diabetes. In this study, the prevalence of elevated glucose concentrations in fatally injured civilian pilots is evaluated. Glucose and HbA1c are measured...whom samples were received during 1998–2005 and whose vitreous fluid and/or urine glucose concentrations were measured. HbA1c levels and information

Performance assessment of a glucose control protocol in septic patients with an automated intermittent plasma glucose monitoring device.

PubMed

Umbrello, M; Salice, V; Spanu, P; Formenti, P; Barassi, A; Melzi d'Eril, G V; Iapichino, G

2014-10-01

The optimal level and modality of glucose control in critically ill patients is still debated. A protocolized approach and the use of nearly-continuous technologies are recommended to manage hyperglycemia, hypoglycemia and glycemic variability. We recently proposed a pato-physiology-based glucose control protocol which takes into account patient glucose/carbohydrate intake and insulin resistance. Aim of the present investigation was to assess the performance of our protocol with an automated intermittent plasma glucose monitoring device (OptiScanner™ 5000). OptiScanner™ was used in 6 septic patients, providing glucose measurement every 15' from a side-port of an indwelling central venous catheter. Target level of glucose was 80-150 mg/dL. Insulin infusion and kcal with nutritional support were also recorded. 6 septic patients were studied for 319 h (1277 measurements); 58 [45-65] hours for each patient (measurements/patient: 231 [172-265]). Blood glucose was at target for 93 [90-98]% of study time. Mean plasma glucose was 126 ± 11 mg/dL. Only 3 hypoglycemic episodes (78, 78, 69 mg/dL) were recorded. Glucose variability was limited: plasma glucose coefficient of variation was 11.7 ± 4.0% and plasma glucose standard deviation was 14.3 ± 5.5 mg/dL. The local glucose control protocol achieved satisfactory glucose control in septic patients along with a high degree of safeness. Automated intermittent plasma glucose monitoring seemed useful to assess the performance of the protocol. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Glucose-sensitive silicone hydrogel contact lens toward tear glucose monitoring.

PubMed

Badugu, Ramachandram; Reece, Edward Albert; Lakowicz, Joseph R

2018-05-01

Accurate and reliable monitoring of blood glucose is needed for the treatment of diabetes, which has many challenges, including lack of patient compliance. Measuring tear glucose is an alternative to traditional finger-stick tests used to track blood sugar levels, but glucose sensing using tears has yet to be achieved. We report a methodology for possible tear glucose monitoring using glucose-sensitive silicone hydrogel (SiHG) contact lenses, the primary type of lenses available in today's market. Initially, we assessed the interpenetrating polymer network, with nearly pure silicone and water regions, existing in the SiHGs using a polarity-sensitive probe Prodan. We then synthesized a glucose-sensitive fluorophore Quin-C18 with a hydrophobic side chain for localization of probe at the interfacial region. Using our glucose-sensing contact lens, we were able to measure varying concentrations of glucose in an in-vitro system. The Quin-C18 strongly bound to the lenses with insignificant leaching even after multiple rinses. The lenses displayed a similar response to glucose after three months of storage in water. This study demonstrates that it may be possible to develop a contact lens for continuous glucose monitoring in the near term, using our concept of fluorophore binding at the silicone-water interface. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

The Accuracy of Point-of-Care Glucose Measurements

PubMed Central

Rebel, Annette; Rice, Mark A.; Fahy, Brenda G.

2012-01-01

Control of blood glucose (BG) in an acceptable range is a major therapy target for diabetes patients in both the hospital and outpatient environments. This review focuses on the state of point-of-care (POC) glucose monitoring and the accuracy of the measurement devices. The accuracy of the POC glucose monitor depends on device methodology and other factors, including sample source and collection and patient characteristics. Patient parameters capable of influencing measurements include variations in pH, blood oxygen, hematocrit, changes in microcirculation, and vasopressor therapy. These elements alone or when combined can significantly impact BG measurement accuracy with POC glucose monitoring devices (POCGMDs). In general, currently available POCGMDs exhibit the greatest accuracy within the range of physiological glucose levels but become less reliable at the lower and higher ranges of BG levels. This issue raises serious safety concerns and the importance of understanding the limitations of POCGMDs. This review will discuss potential interferences and shortcomings of the current POCGMDs and stress when these may impact the reliability of POCGMDs for clinical decision-making. PMID:22538154

Hypoglycemia incidence and risk factors assessment in hospitalized neonates.

PubMed

Zhou, Wei; Yu, Jun; Wu, Yiqi; Zhang, Huawei

2015-03-01

To assess the incidence and risk factors of hypoglycemia in hospitalized neonates in China. Blood glucose level in hospitalized neonates was monitored routinely. Also, in high-risk newborns and neonates with abnormal blood glucose levels in initial detection, the blood sugar level was monitored daily until it was back to normal and stable. Hypoglycemia was detected in 113 out of 668 hospitalized neonates, and the incidence of hypoglycemia was 16.9%. The statistical analysis also showed that hypoglycemia always occurred within one week after birth, especially within three days after birth. Neonates with premature birth, low birth weight and perinatal asphyxia were susceptible to hypoglycemia. Active and continuous monitoring of blood glucose level should be performed in the early newborns, especially in high-risk children, and attention should be paid to timely feeding for the early diagnosis and treatment of neonatal hypoglycemia to reduce its impact on the newborns.

Performance of a continuous glucose monitoring system during controlled hypoglycaemia in healthy volunteers.

PubMed

Cheyne, E H; Cavan, D A; Kerr, D

2002-01-01

It has been suggested that the continuous glucose monitoring system may be a useful tool for detecting unrecognised hypoglycaemia, especially at times when finger prick testing is difficult or impossible (e.g., at night). Studies suggest that subcutaneous glucose levels closely mimic blood glucose levels with a lag time of only a few minutes. However, no studies have been published to show how well the sensor performs during sustained or in recovery from hypoglycaemia. This study involved using a hyperinsulinaemic glucose clamp (60 mU/m2) in nine healthy volunteers. Each subject had two sensors inserted the day before the study. Blood glucose levels were maintained at euglycaemia for the first 60 min, then decreased to 45 mg/dL (2.5 mmol/L) for 60 min, and finally restored to euglycaemia. Blood glucose measurements were compared with interstitial values recorded by the sensor. Sensor profiles showed acceptable agreement with blood glucose levels at each of the three plateaus with a correlation coefficient of 0.79, slope of 0.85, and mean absolute error of 7%. The sensor drop closely matched the drop in blood glucose, but the recovery from hypoglycaemia was delayed by an average of 26 min. Continuous glucose sensing provides a useful means of detecting unrecognised hypoglycaemia in type 1 diabetes, although the duration of hypoglycaemia may be overestimated.

Optical glucose monitoring using vertical cavity surface emitting lasers (VCSELs)

NASA Astrophysics Data System (ADS)

Talebi Fard, Sahba; Hofmann, Werner; Talebi Fard, Pouria; Kwok, Ezra; Amann, Markus-Christian; Chrostowski, Lukas

2009-08-01

Diabetes Mellitus is a common chronic disease that has become a public health issue. Continuous glucose monitoring improves patient health by stabilizing the glucose levels. Optical methods are one of the painless and promising methods that can be used for blood glucose predictions. However, having accuracies lower than what is acceptable clinically has been a major concern. Using lasers along with multivariate techniques such as Partial Least Square (PLS) can improve glucose predictions. This research involves investigations for developing a novel optical system for accurate glucose predictions, which leads to the development of a small, low power, implantable optical sensor for diabetes patients.

Clinical value of Flash glucose monitoring in patients with type 1 diabetes treated with continuous subcutaneous insulin infusion.

PubMed

Moreno-Fernandez, Jesus; Pazos-Couselo, Marcos; González-Rodriguez, Maria; Rozas, Pedro; Delgado, Manuel; Aguirre, Miguel; Garcia-Lopez, Jose Manuel

2018-06-12

To analyze the clinical impact of the Flash glucose monitoring system in patients with type 1 diabetes mellitus (T1DM) treated with continuous subcutaneous insulin infusion (CSII). A 24-week retrospective cohort study in CSII-treated T1DM patients exposed (1:1) to the Flash glucose monitoring system vs. self-monitoring of capillary blood glucose (SMBG). The primary outcome was the difference in hemoglobin A1c (HbA1c) levels between both groups at the end of the study. Thirty-six patients with a mean age of 38.2 years (range 22-55) and a mean T1DM duration of 20.9±7.8 years, treated with CSII for 7.1±5.4 years, were enrolled into the study. At the end of the study, mean HbA1c levels improved in patients in the Flash group (7.1±0.7 vs. 7.8±1.0, p=0.04). Only the Flash group showed a significant decrease in HbA1c levels of -0.4% (95% CI, -0.6, -0.2; p=0.004) during follow-up. Flash patients captured 93.9% of data through 17.8±9.9 scans daily. In fact, the Flash cohort showed a three-fold increase in daily self-monitoring of glucose, while daily frequency of SMBG decreased during the study (-1.8 tests/24h (95% CI -3, -0.7; p=0.01). No safety issues related to Flash use were recorded. The Flash glucose monitoring system is a novel approach to improve blood glucose control in CSII-treated T1DM patients. Randomized controlled trials are needed to assess the effectiveness of this system in CSII-treated T1DM patients. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

Clinical Use of Continuous Glucose Monitoring in Adults with Type 1 Diabetes.

PubMed

Slattery, David; Choudhary, Pratik

2017-05-01

With the emphasis on intensive management of type 1 diabetes, data from studies support frequent monitoring of glucose levels to improve glycemic control and reduce glucose variability, which can be related to an increase in macro and microvascular complications. However, few perform capillary blood glucose that frequently. There are currently two available alternatives that this review will discuss, continuous glucose monitoring (CGM) and flash glucose monitoring. CGM has become an important diagnostic and therapeutic option in optimizing diabetes management. CGM systems are now more accurate, smaller, and easier to use compared to original models. Randomized controlled trials (RCTs) have demonstrated that CGM can improve Hemoglobin A1c (HbA1C) and reduce glucose variability in both continuous subcutaneous insulin infusion and multiple daily injection users. When used in an automated "insulin-suspend" system, reduced frequency of hypoglycemia and shorter time spent in hypoglycemic range have been demonstrated. Despite the potential benefits CGM has to offer in clinical practice, concerns exist on the accuracy of these devices and patient compliance with therapy, which may prevent the true clinical benefit of CGM being achieved, as observed in RCTs. Flash glucose monitoring systems FreeStyle ® Libre™ (Abbott Diabetes Care, Alameda, CA) are as accurate as many CGM systems available and have the added benefit of being factory calibrated. Studies have shown that flash glucose monitoring systems are very well tolerated by patients and effectively reduce glucose variability, increasing time in range.

Millimeter-Wave Sensing of Diabetes-Relevant Glucose Concentration Changes in Pigs

NASA Astrophysics Data System (ADS)

Cano-Garcia, Helena; Saha, Shimul; Sotiriou, Ioannis; Kosmas, Panagiotis; Gouzouasis, Ioannis; Kallos, Efthymios

2018-06-01

The paper presents the first in vivo glucose monitoring animal study in a pig, which correlates radio frequency signal transmission changes with changes in blood glucose concentration in the 58-62 GHz frequency range. The presented non-invasive glucose sensing system consists of two opposite facing patch antennas sandwiching glucose-loaded samples. Prior to the animal study, the system was tested using saline solution samples, for which a linear relationship between changes in transmitted signal and glucose concentration was observed. In the animal study, glucose concentration changes were induced by injecting a known glucose solution in the blood stream. The non-invasive transmission measurements were compared to the glucose levels obtained invasively from the animal. Our results suggest that the system can detect spikes in glucose concentration in the blood, which is an important milestone towards non-invasive glucose monitoring.

Assessment of hypoglycaemia awareness using continuous glucose monitoring.

PubMed

Kubiak, T; Hermanns, N; Schreckling, H J; Kulzer, B; Haak, T

2004-05-01

To investigate the possibility of assessing hypoglycaemia awareness in patients with Type 1 diabetes using continuous glucose monitoring. Twenty patients with Type 1 diabetes were investigated. Ten patients with Type 1 diabetes and strongly impaired hypoglycaemia awareness were compared with 10 patients with intact hypoglycaemia awareness regarding quality of hypoglycaemia perception (number of undetected hypoglycaemic episodes per 24 h, glucose level < 3.3 mmol/l). Hypoglycaemia detection was assessed using the event function of the Continuous Glucose Monitoring System (CGMS; Medtronic MiniMed, Northridge, CA, USA). Patients were instructed to enter an event upon suspecting being hypoglycaemic. Satisfactory CGMS performance could be achieved [mean r = 0.893 between calibration measurements and CGMS data, mean absolute difference (MAD) = 20.6%], although artefacts were observable and had to be controlled. Hypoglycaemia unaware patients showed a significantly higher total number of hypoglycaemic episodes (P < 0.05), number of undetected hypoglycaemic episodes (P < 0.01), and mean glucose levels (P < 0.05). Even in aware patients, undetected hypoglycaemia was observable. No significant differences regarding occurrence of nocturnal hypoglycaemia were observable. The possibility of direct assessment of hypoglycaemia awareness using continuous glucose monitoring was demonstrated. Its application in clinical practice could be of use for assessing hypoglycaemia perception and evaluating the impact of treatment changes on hypoglycaemia awareness.

Non-invasive blood glucose monitor based on spectroscopy using a smartphone.

PubMed

Dantu, Vishnu; Vempati, Jagannadh; Srivilliputhur, Srinivasan

2014-01-01

Development of a novel method for non-invasive measurement of blood glucose concentration using smartphone is discussed. Our research work has three major contributions to society and science. First, we modified and extended the Beer-Lambert's law in physics to accommodate for multiple wavelengths. This extension can aid researchers who wish to perform optical spectroscopy. Second, we successfully developed a creative and non-invasive way for diabetic patients to measure glucose levels via a smartphone. Researchers and chemists can now use their smartphones to determine the absorbance and, therefore, concentration of a chemical. Third, we created an inexpensive way to perform optical spectroscopy by using a smartphone. Monitoring blood glucose using a smartphone application that simply uses equipment already available on smartphones will improve the lives of diabetic patients who can continuously check their blood glucose levels while avoiding the current inconvenient, unhygienic, and costly invasive glucose meters.

Pseudohyperglycemia: Effects of Unwashed Hand after Fruit Peeling or Handling on Fingertips Blood Glucose Monitoring Results.

PubMed

Olamoyegun, M A; Oloyede, T; Adewoye, O G; Abdulkarim, S O; Adeleke, A A

2016-01-01

Self-monitoring of blood glucose (SMBG) is an important component of management for diabetes mellitus (DM), especially in T1DM and T2DM patients who are on insulin therapy. Adequate blood glucose monitoring and prompt intervention are necessary to prevent blood glucose (BG) fluctuation and delay long-term diabetes complications. People with DM are advised to clean their hands before SMBG to remove any dirt or food residue that might affect the reading. The study tested the hypothesis that falsely elevated BG levels from fingertip occur after peeling or handling fruits in an unwashed hand. Fifty apparently healthy nondiabetes volunteers were enrolled. Capillary BG samples were collected from the fingertips after peeling or handling apple, orange, banana, watermelon, and pawpaw, followed by no hand washing for 1 h, cleaning the fingertip with alcohol swab once, five times, and washing hand thoroughly with tap water and drying. These samples were then analyzed with two different glucose meters. The mean BG values, measured from fingertip blood samples after peeling, and handling any of the fruits followed by no hand washing were significantly high, even after cleaning fingertip with a swab of alcohol once. However, there were no significant difference in BG levels measured after peeling and handling fruits followed by hand washing and the level of BG before peeling and handling fruits. Handling of peeled fruits with no hand washing with tap water is associated with overestimation of capillary BG (Pseudohyperglycemia) monitored with glucose meters.

Consistency of Continuous Ambulatory Interstitial Glucose Monitoring Sensors.

PubMed

Wu, Pei T; Segovia, David E; Lee, Cathy C; Nguyen, Kim-Lien

2018-05-16

The abdominal region is the most common location for continuous glucose monitor (CGM) sensor insertion. However, a paucity of post-marketing data is available to demonstrate intra-individual consistency of CGM readings at different abdominal insertion sites. Healthy adults (fasting glucose (FG) < 5.5 mmol/L; BMI < 30 kg/m²) were recruited and a CGM sensor was placed on each side of the abdomen. Postprandial and continuous 48-h interstitial glucose levels were analyzed. There was no significant difference in the 3-h postprandial glucose (PPG) level derived from the left versus right CGM, which remained non-significant after adjusting for waist circumference or FG. Among the glucose levels recorded over 48-h, values on the left site were greater in 3.6% of the data points ( p < 0.05). After adjusting for waist circumference, only 0.5% of the glucose values remained significantly greater on the left ( p < 0.05). When adjusted for FG, similar results were observed. For both PPG and 48-h readings, the mean absolute relative difference was not significant between the two abdominal sites. CGM-derived glucose measures were highly consistent between the left and right abdomen during both the postprandial and post-absorptive periods.

Seventy two-hour glucose monitoring profiles in mild gestational diabetes mellitus: differences from healthy pregnancies and influence of diet counseling.

PubMed

Carreiro, Marina Pimenta; Lauria, Márcio W; Naves, Gabriel Nino T; Miranda, Paulo Augusto C; Leite, Ricardo Barsaglini; Rajão, Kamilla Maria Araújo Brandão; de Aguiar, Regina Amélia Lopes Pessoa; Nogueira, Anelise Impeliziere; Ribeiro-Oliveira, Antônio

2016-09-01

To study glucose profiles of gestational diabetes (GDM) patients with 72 h of continuous glucose monitoring (CGM) either before (GDM1) or after (GDM2) dietary counseling, comparing them with nondiabetic (NDM) controls. We performed CGM on 22 GDM patients; 11 before and 11 after dietary counseling and compared them to 11 healthy controls. Several physiological and clinical characteristics of the glucose profiles were compared across the groups, including comparisons for pooled 24-h measures and hourly median values, summary measures representing glucose exposure (area under the median curves) and variability (amplitude, standard deviation, interquartile range), and time points related to meals. Most women (81.8%) in the GDM groups had fasting glucose <95mg/dL, suggesting mild GDM. Variability, glucose levels 1 and 2h after breakfast and dinner, peak values after dinner and glucose levels between breakfast and lunch, were all significantly higher in GDM1 than NDM (P<0.05 for all comparisons). The GDM2 results were similar to NDM in all aforementioned comparisons (P>0.05). Both GDM groups spent more time with glucose levels above 140mg/dL when compared with the NDM group. No differences among the groups were found for: pooled measurements and hourly comparisons, exposure, nocturnal, fasting, between lunch and dinner and before meals, as well as after lunch (P>0.05 for all). The main differences between the mild GDM1 group and healthy controls were related to glucose variability and excursions above 140mg/dL, while glucose exposure was similar. Glucose levels after breakfast and dinner also discerned the GDM1 group. Dietary counseling was able to keep glucose levels to those of healthy patients. © 2016 European Society of Endocrinology.

[Glucose-monitoring neurons of the medial ventrolateral prefrontal (orbitofrontal) cortex are involved in the maintenance of homeostasis].

PubMed

Szabó, István; Hormay, Edina; Csetényi, Bettina; Nagy, Bernadett; Karádi, Zoltán

2017-05-01

The medial orbitofrontal cortex is involved in the regulation of feeding and metabolism. Little is known, however, about the role of local glucose-monitoring neurons in these processes, and our knowledge is also poor about characteristics of these cells. The functional significance of these chemosensory neurons was to be elucidated. Electrophysiology, by the multibarreled microelectrophoretic technique, and metabolic investigations, after streptozotocin induced selective destruction of the chemosensory neurons, were employed. Fifteen percent of the neurons responded to glucose, and these chemosensory cells displayed differential neurotransmitter and taste sensitivities. In acute glucose tolerance test, at the 30th and 60th minutes, blood glucose level in the streptozotocin-treated rats was significantly higher than that in the controls. The plasma triglyceride concentrations were also higher in the streptozotocin-treated group. Glucose-monitoring neurons of the medial orbitofrontal cortex integrate internal and external environmental signals, and monitor metabolic processes, thus, are indispensable to maintain the healthy homeostasis. Orv Hetil. 2017; 158(18): 692-700.

Determinants of hemoglobin A1c level in patients with type 2 diabetes after in-hospital diabetes education: A study based on continuous glucose monitoring.

PubMed

Torimoto, Keiichi; Okada, Yosuke; Sugino, Sachiko; Tanaka, Yoshiya

2017-05-01

We investigated the relationship between blood glucose profile at hospital discharge, evaluated by continuous glucose monitoring (CGM), and hemoglobin A1c (HbA1c) level at 12 weeks after discharge in patients with type 2 diabetes who received inpatient diabetes education. This was a retrospective study. The participants were 54 patients with type 2 diabetes who did not change their medication after discharge. The mean blood glucose (MBG), standard deviation, coefficient of variation, mean postprandial glucose excursion, maximum blood glucose, minimum blood glucose, percentage of time with blood glucose at ≥180 mg/dL (time at ≥180), percentage of time with blood glucose at ≥140 mg/dL, and percentage of time with blood glucose at <70 mg/dL were measured at admission and discharge using CGM. The primary end-point was the relationship between CGM parameters and HbA1c level at 12 weeks after discharge. The HbA1c level at 12 weeks after discharge correlated with MBG level (r = 0.30, P = 0.029). Multivariate analysis showed that MBG level and disease duration were predictors of 12-week HbA1c level. Multivariate logistic regression analysis was carried out considering goal achievement as a HbA1c level <7.0% 12 weeks after discharge. Disease duration and time at ≥180 were associated with goal achievement. The present results suggested that blood glucose profile at discharge using CGM seems useful to predict HbA1c level after discharge in patients with type 2 diabetes who received inpatient diabetes education. Early treatment to improve MBG level, as well as postprandial hyperglycemia, is important to achieve strict glycemic control. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Noninvasive Diagnostic Devices for Diabetes through Measuring Tear Glucose

PubMed Central

Zhang, Jin; Hodge, William; Hutnick, Cindy; Wang, Xianbin

2011-01-01

This article reviews the development of a noninvasive diagnostic for diabetes by detecting ocular glucose. Early diagnosis and daily management are very important to diabetes patients to ensure a healthy life. Commercial blood glucose sensors have been used since the 1970s. Millions of diabetes patients have to prick their finger for a drop of blood 4–5 times a day to check blood glucose levels—almost 1800 times annually. There is a strong need to have a noninvasive device to help patients to manage the disease easily and painlessly. Instead of detecting the glucose in blood, monitoring the glucose level in other body fluids may provide a feasible approach for noninvasive diagnosis and diabetes control. Tear glucose has been studied for several decades. This article reviews studies on ocular glucose and its monitoring methods. Attempts to continuously monitor the concentration of tear glucose by using contact lens-based sensors are discussed as well as our current development of a nanostructured lens-based sensor for diabetes. This disposable biosensor for the detection of tear glucose may provide an alternative method to help patients manage the disease conveniently. PMID:21303640

Twenty-four-hour variations in blood glucose level in Japanese type 2 diabetes patients based on continuous glucose monitoring.

PubMed

Hajime, Maiko; Okada, Yosuke; Mori, Hiroko; Otsuka, Takashi; Kawaguchi, Mayuko; Miyazaki, Megumi; Kuno, Fumi; Sugai, Kei; Sonoda, Satomi; Tanaka, Kenichi; Kurozumi, Akira; Narisawa, Manabu; Torimoto, Keiichi; Arao, Tadashi; Tanaka, Yoshiya

2018-01-01

High fluctuations in blood glucose are associated with various complications. The correlation between glycated hemoglobin (HbA1c) level and fluctuations in blood glucose level has not been studied in Japanese patients with type 2 diabetes. In the present study, blood glucose profile stratified by HbA1c level was evaluated by continuous glucose monitoring (CGM) in Japanese type 2 diabetes patients. Our retrospective study included 294 patients with type 2 diabetes who were divided by HbA1c level into five groups (≥6.0 to <7.0%, ≥7.0 to <8.0%, ≥8.0 to <9.0%, ≥9.0 to <10.0% and ≥10%). The correlation between HbA1c level and CGM data was analyzed. The primary end-point was the difference in blood glucose fluctuations among the HbA1c groups. The mean blood glucose level increased significantly with increasing HbA1c (P trend  < 0.01). The standard deviation increased with increases in HbA1c (P trend  < 0.01). The mean amplitude of glycemic excursions did not vary significantly with HbA1c. The levels of maximum blood glucose, minimum blood glucose, each preprandial blood glucose, each postprandial maximum blood glucose, range of increase in postprandial glucose from pre-meal to after breakfast, the area under the blood concentration-time curve >180 mg/dL and percentage of the area under the blood concentration-time curve >180 mg/dL were higher with higher HbA1c. Mean glucose level and pre-breakfast blood glucose level were significant and independent determinants of HbA1c. In Japanese patients treated for type 2 diabetes, the mean amplitude of glycemic excursions did not correlate with HbA1c, making it difficult to assess blood glucose fluctuations using HbA1c. Parameters other than HbA1c are required to evaluate fluctuations in blood glucose level in patients receiving treatment for type 2 diabetes. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Metrics for glycaemic control - from HbA1c to continuous glucose monitoring.

PubMed

Kovatchev, Boris P

2017-07-01

As intensive treatment to lower levels of HbA 1c characteristically results in an increased risk of hypoglycaemia, patients with diabetes mellitus face a life-long optimization problem to reduce average levels of glycaemia and postprandial hyperglycaemia while simultaneously avoiding hypoglycaemia. This optimization can only be achieved in the context of lowering glucose variability. In this Review, I discuss topics that are related to the assessment, quantification and optimal control of glucose fluctuations in diabetes mellitus. I focus on markers of average glycaemia and the utility and/or shortcomings of HbA 1c as a 'gold-standard' metric of glycaemic control; the notion that glucose variability is characterized by two principal dimensions, amplitude and time; measures of glucose variability that are based on either self-monitoring of blood glucose data or continuous glucose monitoring (CGM); and the control of average glycaemia and glucose variability through the use of pharmacological agents or closed-loop control systems commonly referred to as the 'artificial pancreas'. I conclude that HbA 1c and the various available metrics of glucose variability reflect the management of diabetes mellitus on different timescales, ranging from months (for HbA 1c ) to minutes (for CGM). Comprehensive assessment of the dynamics of glycaemic fluctuations is therefore crucial for providing accurate and complete information to the patient, physician, automated decision-support or artificial-pancreas system.

Continuous glucose monitoring and HbA1c in the evaluation of glucose metabolism in children at high risk for type 1 diabetes mellitus.

PubMed

Helminen, Olli; Pokka, Tytti; Tossavainen, Päivi; Ilonen, Jorma; Knip, Mikael; Veijola, Riitta

2016-10-01

Continuous glucose monitoring (CGM) parameters, self-monitored blood glucose (SMBG), HbA1c and oral glucose tolerance test (OGTT) were studied during preclinical type 1 diabetes mellitus. Ten asymptomatic children with multiple (⩾2) islet autoantibodies (cases) and 10 age and sex-matched autoantibody-negative controls from the Type 1 Diabetes Prediction and Prevention (DIPP) Study were invited to 7-day CGM with Dexcom G4 Platinum Sensor. HbA1c and two daily SMBG values (morning and evening) were analyzed. Five-point OGTTs were performed and carbohydrate intake was assessed by food records. The matched pairs were compared with the paired sample t-test. The cases showed higher mean values and higher variation in glucose levels during CGM compared to the controls. The time spent ⩾7.8mmol/l was 5.8% in the cases compared to 0.4% in the controls (p=0.040). Postprandial CGM values were similar except after the dinner (6.6mmol/l in cases vs. 6.1mmol/l in controls; p=0.023). When analyzing the SMBG values higher mean level, higher evening levels, as well as higher variation were observed in the cases when compared to the controls. HbA1c was significantly higher in the cases [5.7% (39mmol/mol) vs. 5.3% (34mmol/mol); p=0.045]. No differences were observed in glucose or C-peptide levels during OGTT. Daily carbohydrate intake was slightly higher in the cases (254.2g vs. 217.7g; p=0.034). Glucose levels measured by CGM and SMBG are useful indicators of dysglycemia during preclinical type 1 diabetes mellitus. Increased evening glucose values seem to be common in children with preclinical type 1 diabetes mellitus. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Contribution of fasting and postprandial hyperglycemia to hemoglobin A1c in insulin-treated Japanese diabetic patients.

PubMed

Shimizu, Hiroyuki; Uehara, Yutaka; Okada, Shuichi; Mori, Masatomo

2008-08-01

The contribution of fasting and postprandial glucose to hemoglobin A(1c) (HbA(1c)) levels was evaluated in insulin-treated patients. In 57 insulin-treated, diabetic out-patients, fasting glucose (before breakfast (B-FG), lunch (L-FG) and dinner (D-FG)) and postprandial glucose (B-PPG, L-PPG and D-PPG) levels were determined by the patients themselves at home using glucose self-monitoring apparatus over the course of one week. The correlation between HbA(1c) levels and self monitored blood glucose levels were calculated. In the conventionally treated group, there was a significant correlation between HbA(1c) and fasting glucose (FG) levels only before lunch, but at 2 hr after (PPG) all meals. In the intensively treated group, a significant correlation between HbA(1c) levels and FG levels was found before lunch and at 2 hr after breakfast and dinner. In all subjects, only FG levels before lunch correlated significantly with HbA(1c) levels, although PPG levels were significantly correlated with HbA(1c) at all points. The correlation was highest with PPG after breakfast and dinner. The sum of all FG, PPG and FG + PPG levels was significantly correlated with HbA(1c) levels. Postprandial hyperglycemia after breakfast and dinner should be regarded as most important for improving HbA(1c) levels in insulin treated diabetic patients.

Optical biosensor optimized for continuous in-line glucose monitoring in animal cell culture.

PubMed

Tric, Mircea; Lederle, Mario; Neuner, Lisa; Dolgowjasow, Igor; Wiedemann, Philipp; Wölfl, Stefan; Werner, Tobias

2017-09-01

Biosensors for continuous glucose monitoring in bioreactors could provide a valuable tool for optimizing culture conditions in biotechnological applications. We have developed an optical biosensor for long-term continuous glucose monitoring and demonstrated a tight glucose level control during cell culture in disposable bioreactors. The in-line sensor is based on a commercially available oxygen sensor that is coated with cross-linked glucose oxidase (GOD). The dynamic range of the sensor was tuned by a hydrophilic perforated diffusion membrane with an optimized permeability for glucose and oxygen. The biosensor was thoroughly characterized by experimental data and numerical simulations, which enabled insights into the internal concentration profile of the deactivating by-product hydrogen peroxide. The simulations were carried out with a one-dimensional biosensor model and revealed that, in addition to the internal hydrogen peroxide concentration, the turnover rate of the enzyme GOD plays a crucial role for biosensor stability. In the light of this finding, the glucose sensor was optimized to reach a long functional stability (>52 days) under continuous glucose monitoring conditions with a dynamic range of 0-20 mM and a response time of t 90  ≤ 10 min. In addition, we demonstrated that the sensor was sterilizable with beta and UV irradiation and only subjected to minor cross sensitivity to oxygen, when an oxygen reference sensor was applied. Graphical abstract Measuring setup of a glucose biosensor in a shake flask for continuous glucose monitoring in mammalian cell culture.

Analytical Performance Evaluation of Infopia Element™ Auto-coding Blood Glucose Monitoring System for Self-Monitoring of Blood Glucose.

PubMed

Park, Hae-Il; Lee, Seong-Su; Son, Jang-Won; Kwon, Hee-Sun; Kim, Sung Rae; Chae, Hyojin; Kim, Myungshin; Kim, Yonggoo; Yoo, Soonjib

2016-11-01

Element™ Auto-coding Blood Glucose Monitoring System (BGMS; Infopia Co., Ltd., Anyang-si, Korea) was developed for self-monitoring of blood glucose (SMBG). Precision, linearity, and interference were tested. Eighty-four capillary blood samples measured by Element™ BGMS were compared with central laboratory method (CLM) results in venous serum. Accuracy was evaluated using ISO 15197:2013 criteria. Coefficients of variation (CVs; mean) were 2.4% (44.2 mg/dl), 3.7% (100.6 mg/dl), and 2.1% (259.8 mg/dl). Linearity was shown at concentrations 39.25-456.25 mg/l (y = 0.989 + 0.984x, SE = 17.63). Up to 15 mg/dl of galactose, ascorbic acid, and acetaminophen, interference > 10.4% was not observed. Element™ BGMS glucose was higher than CLM levels by 3.2 mg/dl (at 200 mg/dl) to 8.2 mg/dl (at 100 mg/dl). The minimum specification for bias (3.3%) was met at 140 and 200 mg/l glucose. In the Clarke and consensus error grids, 100% of specimens were within zone A and B. For Element™ BGMS values, 92.9% (78/84) to 94.0% (79/84) were within a 15 mg/dl (< 100 mg/dl) or 15% (> 100 mg/dl) of the average CLM value. Element™ BGMS was considered an appropriate SMBG for home use; however, the positive bias at low-to-mid glucose levels requires further improvement. © 2016 Wiley Periodicals, Inc.

Alarm characterization for continuous glucose monitors used as adjuncts to self-monitoring of blood glucose.

PubMed

McGarraugh, Geoffrey

2010-01-01

Continuous glucose monitoring (CGM) devices available in the United States are approved for use as adjuncts to self-monitoring of blood glucose (SMBG). Alarm evaluation in the Clinical and Laboratory Standards Institute (CLSI) guideline for CGM does not specifically address devices that employ both CGM and SMBG. In this report, an alarm evaluation method is proposed for these devices. The proposed method builds on the CLSI method using data from an in-clinic study of subjects with type 1 diabetes. CGM was used to detect glycemic events, and SMBG was used to determine treatment. To optimize detection of a single glucose level, such as 70 mg/dl, a range of alarm threshold settings was evaluated. The alarm characterization provides a choice of alarm settings that trade off detection and false alarms. Detection of a range of high glucose levels was similarly evaluated. Using low glucose alarms, detection of 70 mg/dl within 30 minutes increased from 64 to 97% as alarm settings increased from 70 to 100 mg/dl, and alarms that did not require treatment (SMBG >85 mg/dl) increased from 18 to 52%. Using high glucose alarms, detection of 180 mg/dl within 30 minutes increased from 87 to 96% as alarm settings decreased from 180 to 165 mg/dl, and alarms that did not require treatment (SMBG <180 mg/dl) increased from 24 to 42%. The proposed alarm evaluation method provides information for choosing appropriate alarm thresholds and reflects the clinical utility of CGM alarms. 2010 Diabetes Technology Society.

A Disposable Tear Glucose Biosensor—Part 4

PubMed Central

Engelschall, Erica; Lan, Kenneth; Shah, Pankti; Saez, Neil; Maxwell, Stephanie; Adamson, Teagan; Abou-Eid, Michelle; McAferty, Kenyon; Patel, Dharmendra R.; Cook, Curtiss B.

2014-01-01

Objective: A prototype tear glucose (TG) sensor was tested in New Zealand white rabbits to assess eye irritation, blood glucose (BG) and TG lag time, and correlation with BG. Methods: A total of 4 animals were used. Eye irritation was monitored by Lissamine green dye and analyzed using image analysis software. Lag time was correlated with an oral glucose load while recording TG and BG readings. Correlation between TG and BG were plotted against one another to form a correlation diagram, using a Yellow Springs Instrument (YSI) and self-monitoring of blood glucose as the reference measurements. Finally, TG levels were calculated using analytically derived expressions. Results: From repeated testing carried over the course of 12 months, little to no eye irritation was detected. TG fluctuations over time visually appeared to trace the same pattern as BG with an average lag times of 13 minutes. TG levels calculated from the device current measurements ranged from 4 to 20 mg/dL and correlated linearly with BG levels of 75-160 mg/dL (TG = 0.1723 BG = 7.9448 mg/dL; R2 = .7544). Conclusion: The first steps were taken toward preliminary development of a sensor for self-monitoring of tear glucose (SMTG). No conjunctival irritation in any of the animals was noted. Lag time between TG and BG was found to be noticeable, but a quantitative modeling to correlate lag time in this study is unnecessary. Measured currents from the sensors and the calculated TG showed promising correlation to BG levels. Previous analytical bench marking showed BG and TG levels consistent with other literature. PMID:24876546

Dual-wavelength polarimetric glucose sensing in the presence of birefringence and motion artifact using anterior chamber of the eye phantoms

PubMed Central

Pirnstill, Casey W.; Coté, Gerard L.

2013-01-01

Abstract. Noninvasive glucose monitoring is being investigated as a tool for effectively managing diabetes mellitus. Optical polarimetry has emerged as one such method, which can potentially be used to ascertain blood glucose levels by measuring the aqueous humor glucose levels in the anterior chamber of the eye. The key limitation for realizing this technique is the presence of sample noise due to corneal birefringence, which in the presence of motion artifact can confound the glucose signature in the aqueous humor of the eye. We present the development and characterization of a real-time, closed-loop, dual-wavelength polarimetric system for glucose monitoring using both a custom-built plastic eye phantom (in vitro) and isolated rabbit corneas (ex vivo) mounted in an artificial anterior chamber. The results show that the system can account for these noise sources and can monitor physiologic glucose levels accurately for a limited range of motion-induced birefringence. Using the dual-wavelength system in vitro and ex vivo, standard errors were 14.5  mg/dL and 22.4  mg/dL, respectively, in the presence of birefringence with motion. The results indicate that although dual-wavelength polarimetry has a limited range of compensation for motion-induced birefringence, when aligned correctly, it can minimize the effect of time-varying corneal birefringence for a range of motion larger than what has been reported in vivo. PMID:23299516

Evaluation of MOSFET-type glucose sensor using platinum electrode with glucose oxidase

NASA Astrophysics Data System (ADS)

Ooe, Katsutoshi; Hamamoto, Yasutaro; Hirano, Yoshiaki

2005-02-01

As the population ages, health management will be one of the important issues. The development of a safe medical machine based on MEMS technologies for the human body will be the primary research project in the future. We have developed the glucose sensor, as one of the medical based devices, for use in the Health Monitoring System (HMS). HMS is the device that continuously monitors human health conditions. For example, blood is the monitoring target of HMS. The glucose sensor specifically detects the glucose levels of the blood and monitors the glucose concentration as the blood sugar level. This glucose sensor has a "separated Au electrode", which immobilizes GOx. In our previous work, GOx was immobilized onto Au electrode by the SAMs (Self-Assembled Monolayer) method, and the sensor, using this working electrode, detected the glucose concentration of an aqueous glucose solution. In this report, we used a Pt electrode, which immobilized GOx, as a working electrode. Au electrode, which was used previously, was dissolved by the application of current in the presence of chloride ions. Based on the above-mentioned fact, a new working electrode, which immobilized GOx, was produced using Pt, which did not possess such characteristics. These Pt working electrodes were produced using the covalent binding method and the cross-link method, and both the electrodes displayed a good sensing property. In addition, the electrode using glutaraldehyde (GA) and bovine serum albumin (BSA) as crosslinking agents was produced, and it displayed better characteristics as compared with those displayed by the electrode that used only GA. Based on the above-mentioned techniques, the improvement in performance of the sensor was confirmed.

Wearable/disposable sweat-based glucose monitoring device with multistage transdermal drug delivery module

PubMed Central

Lee, Hyunjae; Song, Changyeong; Hong, Yong Seok; Kim, Min Sung; Cho, Hye Rim; Kang, Taegyu; Shin, Kwangsoo; Choi, Seung Hong; Hyeon, Taeghwan; Kim, Dae-Hyeong

2017-01-01

Electrochemical analysis of sweat using soft bioelectronics on human skin provides a new route for noninvasive glucose monitoring without painful blood collection. However, sweat-based glucose sensing still faces many challenges, such as difficulty in sweat collection, activity variation of glucose oxidase due to lactic acid secretion and ambient temperature changes, and delamination of the enzyme when exposed to mechanical friction and skin deformation. Precise point-of-care therapy in response to the measured glucose levels is still very challenging. We present a wearable/disposable sweat-based glucose monitoring device integrated with a feedback transdermal drug delivery module. Careful multilayer patch design and miniaturization of sensors increase the efficiency of the sweat collection and sensing process. Multimodal glucose sensing, as well as its real-time correction based on pH, temperature, and humidity measurements, maximizes the accuracy of the sensing. The minimal layout design of the same sensors also enables a strip-type disposable device. Drugs for the feedback transdermal therapy are loaded on two different temperature-responsive phase change nanoparticles. These nanoparticles are embedded in hyaluronic acid hydrogel microneedles, which are additionally coated with phase change materials. This enables multistage, spatially patterned, and precisely controlled drug release in response to the patient’s glucose level. The system provides a novel closed-loop solution for the noninvasive sweat-based management of diabetes mellitus. PMID:28345030

Alarm characterization for a continuous glucose monitor that replaces traditional blood glucose monitoring.

PubMed

McGarraugh, Geoffrey

2010-01-01

Continuous glucose monitoring (CGM) devices available in the United States are approved for use as adjuncts to self-monitoring of blood glucose (SMBG); all CGM alarms require SMBG confirmation before treatment. In this report, an analysis method is proposed to determine the CGM threshold alarm accuracy required to eliminate SMBG confirmation. The proposed method builds on the Clinical and Laboratory Standards Institute (CLSI) guideline for evaluating CGM threshold alarms using data from an in-clinic study of subjects with type 1 diabetes. The CLSI method proposes a maximum time limit of +/-30 minutes for the detection of hypo- and hyperglycemic events but does not include limits for glucose measurement accuracy. The International Standards Organization (ISO) standard for SMBG glucose measurement accuracy (ISO 15197) is +/-15 mg/dl for glucose <75 mg/dl and +/-20% for glucose > or = 75 mg/dl. This standard was combined with the CLSI method to more completely characterize the accuracy of CGM alarms. Incorporating the ISO 15197 accuracy margins, FreeStyle Navigator CGM system alarms detected 70 mg/dl hypoglycemia within 30 minutes at a rate of 70.3%, with a false alarm rate of 11.4%. The device detected high glucose in the range of 140-300 mg/dl within 30 minutes at an average rate of 99.2%, with a false alarm rate of 2.1%. Self-monitoring of blood glucose confirmation is necessary for detecting and treating hypoglycemia with the FreeStyle Navigator CGM system, but at high glucose levels, SMBG confirmation adds little incremental value to CGM alarms. 2010 Diabetes Technology Society.

Overcoming Clinical Inertia: A Randomized Clinical Trial of a Telehealth Remote Monitoring Intervention Using Paired Glucose Testing in Adults With Type 2 Diabetes

PubMed Central

Blozis, Shelley A; Young, Heather M; Nesbitt, Thomas S; Quinn, Charlene C

2015-01-01

Background Type 2 diabetes mellitus is a worldwide challenge. Practice guidelines promote structured self-monitoring of blood glucose (SMBG) for informing health care providers about glycemic control and providing patient feedback to increase knowledge, self-efficacy, and behavior change. Paired glucose testing—pairs of glucose results obtained before and after a meal or physical activity—is a method of structured SMBG. However, frequent access to glucose data to interpret values and recommend actions is challenging. A complete feedback loop—data collection and interpretation combined with feedback to modify treatment—has been associated with improved outcomes, yet there remains limited integration of SMBG feedback in diabetes management. Incorporating telehealth remote monitoring and asynchronous electronic health record (EHR) feedback from certified diabetes educators (CDEs)—specialists in glucose pattern management—employ the complete feedback loop to improve outcomes. Objective The purpose of this study was to evaluate a telehealth remote monitoring intervention using paired glucose testing and asynchronous data analysis in adults with type 2 diabetes. The primary aim was change in glycated hemoglobin (A1c)—a measure of overall glucose management—between groups after 6 months. The secondary aims were change in self-reported Summary of Diabetes Self-Care Activities (SDSCA), Diabetes Empowerment Scale, and Diabetes Knowledge Test. Methods A 2-group randomized clinical trial was conducted comparing usual care to telehealth remote monitoring with paired glucose testing and asynchronous virtual visits. Participants were aged 30-70 years, not using insulin with A1c levels between 7.5% and 10.9% (58-96 mmol/mol). The telehealth remote monitoring tablet computer transmitted glucose data and facilitated a complete feedback loop to educate participants, analyze actionable glucose data, and provide feedback. Data from paired glucose testing were analyzed asynchronously using computer-assisted pattern analysis and were shared with patients via the EHR weekly. CDEs called participants monthly to discuss paired glucose testing trends and treatment changes. Separate mixed-effects models were used to analyze data. Results Participants (N=90) were primarily white (64%, 56/87), mean age 58 (SD 11) years, mean body mass index 34.1 (SD 6.7) kg/m2, with diabetes for mean 8.2 (SD 5.4) years, and a mean A1c of 8.3% (SD 1.1; 67 mmol/mol). Both groups lowered A1c with an estimated average decrease of 0.70 percentage points in usual care group and 1.11 percentage points in the treatment group with a significant difference of 0.41 percentage points at 6 months (SE 0.08, t159=–2.87, P=.005). Change in medication (SE 0.21, t157=–3.37, P=.009) was significantly associated with lower A1c level. The treatment group significantly improved on the SDSCA subscales carbohydrate spacing (P=.04), monitoring glucose (P=.001), and foot care (P=.02). Conclusions An eHealth model incorporating a complete feedback loop with telehealth remote monitoring and paired glucose testing with asynchronous data analysis significantly improved A1c levels compared to usual care. Trial Registration Clinicaltrials.gov NCT01715649; https://www.clinicaltrials.gov/ct2/show/NCT01715649 (Archived by WebCite at http://www.webcitation.org/6ZinLl8D0). PMID:26199142

Overcoming Clinical Inertia: A Randomized Clinical Trial of a Telehealth Remote Monitoring Intervention Using Paired Glucose Testing in Adults With Type 2 Diabetes.

PubMed

Greenwood, Deborah A; Blozis, Shelley A; Young, Heather M; Nesbitt, Thomas S; Quinn, Charlene C

2015-07-21

Type 2 diabetes mellitus is a worldwide challenge. Practice guidelines promote structured self-monitoring of blood glucose (SMBG) for informing health care providers about glycemic control and providing patient feedback to increase knowledge, self-efficacy, and behavior change. Paired glucose testing—pairs of glucose results obtained before and after a meal or physical activity—is a method of structured SMBG. However, frequent access to glucose data to interpret values and recommend actions is challenging. A complete feedback loop—data collection and interpretation combined with feedback to modify treatment—has been associated with improved outcomes, yet there remains limited integration of SMBG feedback in diabetes management. Incorporating telehealth remote monitoring and asynchronous electronic health record (EHR) feedback from certified diabetes educators (CDEs)—specialists in glucose pattern management—employ the complete feedback loop to improve outcomes. The purpose of this study was to evaluate a telehealth remote monitoring intervention using paired glucose testing and asynchronous data analysis in adults with type 2 diabetes. The primary aim was change in glycated hemoglobin (A(1c))—a measure of overall glucose management—between groups after 6 months. The secondary aims were change in self-reported Summary of Diabetes Self-Care Activities (SDSCA), Diabetes Empowerment Scale, and Diabetes Knowledge Test. A 2-group randomized clinical trial was conducted comparing usual care to telehealth remote monitoring with paired glucose testing and asynchronous virtual visits. Participants were aged 30-70 years, not using insulin with A1c levels between 7.5% and 10.9% (58-96 mmol/mol). The telehealth remote monitoring tablet computer transmitted glucose data and facilitated a complete feedback loop to educate participants, analyze actionable glucose data, and provide feedback. Data from paired glucose testing were analyzed asynchronously using computer-assisted pattern analysis and were shared with patients via the EHR weekly. CDEs called participants monthly to discuss paired glucose testing trends and treatment changes. Separate mixed-effects models were used to analyze data. Participants (N=90) were primarily white (64%, 56/87), mean age 58 (SD 11) years, mean body mass index 34.1 (SD 6.7) kg/m2, with diabetes for mean 8.2 (SD 5.4) years, and a mean A(1c) of 8.3% (SD 1.1; 67 mmol/mol). Both groups lowered A(1c) with an estimated average decrease of 0.70 percentage points in usual care group and 1.11 percentage points in the treatment group with a significant difference of 0.41 percentage points at 6 months (SE 0.08, t159=-2.87, P=.005). Change in medication (SE 0.21, t157=-3.37, P=.009) was significantly associated with lower A(1c) level. The treatment group significantly improved on the SDSCA subscales carbohydrate spacing (P=.04), monitoring glucose (P=.001), and foot care (P=.02). An eHealth model incorporating a complete feedback loop with telehealth remote monitoring and paired glucose testing with asynchronous data analysis significantly improved A(1c) levels compared to usual care. Clinicaltrials.gov NCT01715649; https://www.clinicaltrials.gov/ct2/show/NCT01715649 (Archived by WebCite at http://www.webcitation.org/6ZinLl8D0).

Can the Accuracy of Home Blood Glucose Monitors be affected by the Received Signal Strength of 900 MHz GSM Mobile Phones?

PubMed Central

Eslami, J.; Ghafaripour, F.; Mortazavi, S.A.R.; Mortazavi, S.M.J.; Shojaei-fard, M.B.

2015-01-01

Background People who use home blood glucose monitors may use their mobile phones in the close vicinity of medical devices. This study is aimed at investigating the effect of the signal strength of 900 MHz GSM mobile phones on the accuracy of home blood glucose monitors. Methods Sixty non-diabetic volunteer individuals aged 21 - 28 years participated in this study. Blood samples were analyzed for glucose level by using a common blood glucose monitoring system. Each blood sample was analyzed twice, within ten minutes in presence and absence of electromagnetic fields generated by a common GSM mobile phone during ringing. Blood samples were divided into 3 groups of 20 samples each. Group 1: exposure to mobile phone radiation with weak signal strength. Group2: exposure to mobile phone radiation with strong signal strength. Group3: exposure to a switched–on mobile phone with no signal strength. Results The magnitude of the changes in the first, second and third group between glucose levels of two measurements (׀ΔC׀) were 7.4±3.9 mg/dl, 10.2±4.5 mg/dl, 8.7±8.4 mg/dl respectively. The difference in the magnitude of the changes between the 1st and the 3rd groups was not statistically significant. Furthermore, the difference in the magnitude of the changes between the 2nd and the 3rd groups was not statistically significant. Conclusion Findings of this study showed that the signal strength of 900 MHz GSM mobile phones cannot play a significant role in changing the accuracy of home blood glucose monitors. PMID:26688798

Can the Accuracy of Home Blood Glucose Monitors be affected by the Received Signal Strength of 900 MHz GSM Mobile Phones?

PubMed

Eslami, J; Ghafaripour, F; Mortazavi, S A R; Mortazavi, S M J; Shojaei-Fard, M B

2015-12-01

People who use home blood glucose monitors may use their mobile phones in the close vicinity of medical devices. This study is aimed at investigating the effect of the signal strength of 900 MHz GSM mobile phones on the accuracy of home blood glucose monitors. Sixty non-diabetic volunteer individuals aged 21 - 28 years participated in this study. Blood samples were analyzed for glucose level by using a common blood glucose monitoring system. Each blood sample was analyzed twice, within ten minutes in presence and absence of electromagnetic fields generated by a common GSM mobile phone during ringing. Blood samples were divided into 3 groups of 20 samples each. Group 1: exposure to mobile phone radiation with weak signal strength. Group2: exposure to mobile phone radiation with strong signal strength. Group3: exposure to a switched-on mobile phone with no signal strength. The magnitude of the changes in the first, second and third group between glucose levels of two measurements (׀ΔC׀) were 7.4±3.9 mg/dl, 10.2±4.5 mg/dl, 8.7±8.4 mg/dl respectively. The difference in the magnitude of the changes between the 1st and the 3rd groups was not statistically significant. Furthermore, the difference in the magnitude of the changes between the 2nd and the 3rd groups was not statistically significant. Findings of this study showed that the signal strength of 900 MHz GSM mobile phones cannot play a significant role in changing the accuracy of home blood glucose monitors.

New technologies in the treatment of type 1 diabetes.

PubMed

Schmidt, Signe

2013-11-01

Type 1 diabetes is a chronic condition characterized by insufficient production of insulin, a hormone needed for proper control of blood glucose levels. People with type 1 diabetes must monitor their blood glucose throughout the day using a glucose meter or a continuous glucose monitor, calculate how much insulin is needed to maintain normal blood glucose levels, and administer the insulin dose by pen injection or insulin pump infusion into the subcutaneous tissue. In recent years, several new technologies for the treatment of type 1 diabetes have been developed. This PhD thesis covers two studies of the effects of commercially available technologies--sensor-augmented pump therapy and automated insulin bolus calculators--when used in clinical practice. Both studies demonstrated that these technologies have the potential to improve diabetes care. In addition, two in-clinic studies related to emerging technologies--closed-loop glucose control and virtual simulation environments--are included in the thesis. The results of these experiments provided proof of concept and will serve as a basis for further research in these fields.

[Current status and recommendations on the use of continuous blood glucose monitoring systems in children and adolescents with type 1 diabetes mellitus].

PubMed

Torres Lacruz, M; Barrio Castellanos, R; García Cuartero, B; Gómez Gila, A; González Casado, I; Hermoso López, F; Luzuriaga Tomás, C; Oyarzabal Irigoyen, M; Rica Etxebarria, I; Rodríguez Rigual, M

2011-08-01

Glucose monitoring methods have made great advances in the last decade with the appearance of the continuous glucose monitoring systems (CGMS) that measure the glucose levels in the interstitial liquid, providing information about glucose patterns and trends, but do not replace the self-monitoring of capillary glucose. Improvement in diabetes control using the CGMS depends on the motivation and training received by the patient and family and on the continuity in its use. Due to the development and widespread use of these systems in clinical practice, the diabetes group of the Sociedad Española de Endocrinología Pediátrica has drafted a document of consensus for their indication and use in children and adolescents. Only a limited number of trials have been performed in children and adolescent populations. More data are needed on the use of this technology in order to define the impact on metabolic control. Copyright © 2010 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Mobile communication using a mobile phone with a glucometer for glucose control in Type 2 patients with diabetes: as effective as an Internet-based glucose monitoring system.

PubMed

Cho, Jae-Hyoung; Lee, Hye-Chung; Lim, Dong-Jun; Kwon, Hyuk-Sang; Yoon, Kun-Ho

2009-01-01

A mobile phone with a glucometer integrated into the battery pack (the 'Diabetes Phone') was launched in Korea in 2003. We compared its effect on management of type 2 diabetes to the Internet-based glucose monitoring system (IBGMS), which had been studied previously. We conducted a randomized trial involving 69 patients for three months. Participants were assigned to an Internet group or a phone group. The phone group communicated with medical staff through the mobile phone only. Their glucose-monitoring data were automatically transferred to individual, web-based charts and they received medical recommendations by short message service. The Internet group used the IBGMS. There were no significant differences between the groups at baseline. After three months' intervention, HbA(1c) levels of both groups had decreased significantly, from 7.6% to 6.9% for the Internet group and from 8.3% to 7.1% for the phone group (P < 0.01). Levels of patient satisfaction and adherence to medical advice were similar. Mobile, bidirectional communication between doctors and patients using the diabetes phone was as effective for glucose control as the previously-studied Internet-based monitoring system and it was good for patient satisfaction and adherence.

Carbon Disulfide (CS2) Interference in Glucose Metabolism from Unconventional Oil and Gas Extraction and Processing Emissions.

PubMed

Rich, Alisa L; Patel, Jay T; Al-Angari, Samiah S

2016-01-01

Carbon disulfide (CS2) has been historically associated with the manufacturing of rayon, cellophane, and carbon tetrachloride production. This study is one of the first to identify elevated atmospheric levels of CS2 above national background levels and its mechanisms to dysregulate normal glucose metabolism. Interference in glucose metabolism can indirectly cause other complications (diabetes, neurodegenerative disease, and retinopathy), which may be preventable if proper precautions are taken. Rich et al found CS2 and 12 associated sulfide compounds present in the atmosphere in residential areas where unconventional shale oil and gas extraction and processing operations were occurring. Ambient atmospheric concentrations of CS2 ranged from 0.7 parts per billion by volume (ppbv) to 103 ppbv over a continuous 24-hour monitoring period. One-hour ambient atmospheric concentrations ranged from 3.4 ppbv to 504.6 ppbv. Using the U.S. Environmental Protection Agency Urban Air Toxic Monitoring Program study as a baseline comparison for atmospheric CS2 concentrations found in this study, it was determined that CS2 atmospheric levels were consistently elevated in areas where unconventional oil and gas extraction and processing occurred. The mechanisms by which CS2 interferes in normal glucose metabolism by dysregulation of the tryptophan metabolism pathway are presented in this study. The literature review found an increased potential for alteration of normal glucose metabolism in viscose rayon occupational workers exposed to CS2. Occupational workers in the energy extraction industry exposed to CS2 and other sulfide compounds may have an increased potential for glucose metabolism interference, which has been an indicator for diabetogenic effect and other related health impacts. The recommendation of this study is for implementation of regular monitoring of blood glucose levels in CS2-exposed populations as a preventative health measure.

Evaluation of Blood Glucose Meter Efficacy in an Antenatal Diabetes Clinic.

PubMed

McGrath, Rachel T; Donnelly, Vanessa C; Glastras, Sarah J; Preda, Veronica A; Sheriff, Nisa; Ward, Peter; Hocking, Samantha L; Fulcher, Gregory R

2016-02-01

The optimal treatment of diabetes in pregnancy requires accurate measurement of blood glucose levels, in order to minimize adverse outcomes for both mother and neonate. Self-monitoring of blood glucose is routinely used to measure glycemic control and to assess whether treatment targets are being met; however, the accuracy of blood glucose meters in pregnancy is unclear. Pregnant women with gestational, type 1, or type 2 diabetes mellitus were eligible to participate. Nonfasting capillary blood glucose levels were measured in duplicate using the BGStar(®) (Sanofi, Sydney, Australia) and FreeStyle Lite(®) (Abbott, Sydney) blood glucose meters. Venous blood samples were collected and analyzed for plasma glucose, hematocrit, and glycated hemoglobin. Capillary blood glucose was compared with plasma glucose and further assessed according to International Organization for Standardization (ISO) 15197:2013 standards. One hundred ten women were recruited, providing 96 samples suitable for analysis. The mean ± SD laboratory plasma glucose level was 4.6 ± 1.4 mmol/L; the BGStar and FreeStyle Lite capillary blood glucose values were 5.3 ± 1.4 mmol/L and 5.0 ± 1.3 mmol/L, respectively. Both meters showed a positive bias (0.42 mmol/L for the FreeStyle Lite and 0.65 mmol/L for the BGStar). Furthermore, neither meter fulfilled the ISO 15197:2013 standards, and there was a nonsignificant improvement in meter performance at blood glucose levels of ≤4.2 mmol/L. Hematocrit did not affect the results of either blood glucose meter. Clarke Error Grid analysis demonstrated that approximately 70% of the results of both meters would lead to appropriate clinical action. The BGStar and FreeStyle Lite blood glucose meters did not meet ISO 15197:2013 recommendations for blood glucose monitoring systems when assessed in a population of women with diabetes in pregnancy. Clinicians should consider this difference in blood glucose readings when making diabetes-related treatment decisions.

Development and Validation of a Rapid (13)C6-Glucose Isotope Dilution UPLC-MRM Mass Spectrometry Method for Use in Determining System Accuracy and Performance of Blood Glucose Monitoring Devices.

PubMed

Matsunami, Risë K; Angelides, Kimon; Engler, David A

2015-05-18

There is currently considerable discussion about the accuracy of blood glucose concentrations determined by personal blood glucose monitoring systems (BGMS). To date, the FDA has allowed new BGMS to demonstrate accuracy in reference to other glucose measurement systems that use the same or similar enzymatic-based methods to determine glucose concentration. These types of reference measurement procedures are only comparative in nature and are subject to the same potential sources of error in measurement and system perturbations as the device under evaluation. It would be ideal to have a completely orthogonal primary method that could serve as a true standard reference measurement procedure for establishing the accuracy of new BGMS. An isotope-dilution liquid chromatography/mass spectrometry (ID-UPLC-MRM) assay was developed using (13)C6-glucose as a stable isotope analogue to specifically measure glucose concentration in human plasma, and validated for use against NIST standard reference materials, and against fresh isolates of whole blood and plasma into which exogenous glucose had been spiked. Assay performance was quantified to NIST-traceable dry weight measures for both glucose and (13)C6-glucose. The newly developed assay method was shown to be rapid, highly specific, sensitive, accurate, and precise for measuring plasma glucose levels. The assay displayed sufficient dynamic range and linearity to measure across the range of both normal and diabetic blood glucose levels. Assay performance was measured to within the same uncertainty levels (<1%) as the NIST definitive method for glucose measurement in human serum. The newly developed ID UPLC-MRM assay can serve as a validated reference measurement procedure to which new BGMS can be assessed for glucose measurement performance. © 2015 Diabetes Technology Society.

Development and Validation of a Rapid 13C6-Glucose Isotope Dilution UPLC-MRM Mass Spectrometry Method for Use in Determining System Accuracy and Performance of Blood Glucose Monitoring Devices

PubMed Central

Matsunami, Risë K.; Angelides, Kimon; Engler, David A.

2015-01-01

Background: There is currently considerable discussion about the accuracy of blood glucose concentrations determined by personal blood glucose monitoring systems (BGMS). To date, the FDA has allowed new BGMS to demonstrate accuracy in reference to other glucose measurement systems that use the same or similar enzymatic-based methods to determine glucose concentration. These types of reference measurement procedures are only comparative in nature and are subject to the same potential sources of error in measurement and system perturbations as the device under evaluation. It would be ideal to have a completely orthogonal primary method that could serve as a true standard reference measurement procedure for establishing the accuracy of new BGMS. Methods: An isotope-dilution liquid chromatography/mass spectrometry (ID-UPLC-MRM) assay was developed using 13C6-glucose as a stable isotope analogue to specifically measure glucose concentration in human plasma, and validated for use against NIST standard reference materials, and against fresh isolates of whole blood and plasma into which exogenous glucose had been spiked. Assay performance was quantified to NIST-traceable dry weight measures for both glucose and 13C6-glucose. Results: The newly developed assay method was shown to be rapid, highly specific, sensitive, accurate, and precise for measuring plasma glucose levels. The assay displayed sufficient dynamic range and linearity to measure across the range of both normal and diabetic blood glucose levels. Assay performance was measured to within the same uncertainty levels (<1%) as the NIST definitive method for glucose measurement in human serum. Conclusions: The newly developed ID UPLC-MRM assay can serve as a validated reference measurement procedure to which new BGMS can be assessed for glucose measurement performance. PMID:25986627

Monitoring nutrition and glucose in acute brain injury.

PubMed

Badjatia, Neeraj; Vespa, Paul

2014-12-01

The metabolic response to injury is well described; however, very little is understood about optimal markers to measure this response. This summary will address the current evidence about monitoring nutritional status including blood glucose after acute brain injury (ABI). An electronic literature search was conducted for English language articles describing the testing, utility, and optimal methods to measure nutritional status and blood glucose levels in the neurocritical care population. A total of 45 articles were included in this review. Providing adequate and timely nutritional support can help improve outcome after ABI. However, the optimal content and total nutrition requirements remain unclear. In addition, how best to monitor the nutritional status in ABI is still being elucidated, and at present, there is no validated optimal method to monitor the global response to nutritional support on a day-to-day basis in ABI patients. Nitrogen balance may be monitored to assess the adequacy of caloric intake as it relates to protein energy metabolism, but indirect calorimetry, anthropometric measurement, or serum biomarker requires further validation. The adverse effects of hyperglycemia in ABI are well described, and data indicate that blood glucose should be carefully controlled in critically ill patients. However, the optimal frequency or duration for blood glucose monitoring after ABI remains poorly defined. There are significant knowledge gaps about monitoring nutritional status and response to nutritional interventions in ABI; these need to be addressed and hence few recommendations can be made. The optimal frequency and duration of blood glucose monitoring need further study.

Insulin Induces an Increase in Cytosolic Glucose Levels in 3T3-L1 Cells with Inhibited Glycogen Synthase Activation

PubMed Central

Chowdhury, Helena H.; Kreft, Marko; Jensen, Jørgen; Zorec, Robert

2014-01-01

Glucose is an important source of energy for mammalian cells and enters the cytosol via glucose transporters. It has been thought for a long time that glucose entering the cytosol is swiftly phosphorylated in most cell types; hence the levels of free glucose are very low, beyond the detection level. However, the introduction of new fluorescence resonance energy transfer-based glucose nanosensors has made it possible to measure intracellular glucose more accurately. Here, we used the fluorescent indicator protein (FLIPglu-600µ) to monitor cytosolic glucose dynamics in mouse 3T3-L1 cells in which glucose utilization for glycogen synthesis was inhibited. The results show that cells exhibit a low resting cytosolic glucose concentration. However, in cells with inhibited glycogen synthase activation, insulin induced a robust increase in cytosolic free glucose. The insulin-induced increase in cytosolic glucose in these cells is due to an imbalance between the glucose transported into the cytosol and the use of glucose in the cytosol. In untreated cells with sensitive glycogen synthase activation, insulin stimulation did not result in a change in the cytosolic glucose level. This is the first report of dynamic measurements of cytosolic glucose levels in cells devoid of the glycogen synthesis pathway. PMID:25279585

A Disposable Tear Glucose Biosensor-Part 4: Preliminary Animal Model Study Assessing Efficacy, Safety, and Feasibility.

PubMed

La Belle, Jeffrey T; Engelschall, Erica; Lan, Kenneth; Shah, Pankti; Saez, Neil; Maxwell, Stephanie; Adamson, Teagan; Abou-Eid, Michelle; McAferty, Kenyon; Patel, Dharmendra R; Cook, Curtiss B

2014-01-01

A prototype tear glucose (TG) sensor was tested in New Zealand white rabbits to assess eye irritation, blood glucose (BG) and TG lag time, and correlation with BG. A total of 4 animals were used. Eye irritation was monitored by Lissamine green dye and analyzed using image analysis software. Lag time was correlated with an oral glucose load while recording TG and BG readings. Correlation between TG and BG were plotted against one another to form a correlation diagram, using a Yellow Springs Instrument (YSI) and self-monitoring of blood glucose as the reference measurements. Finally, TG levels were calculated using analytically derived expressions. From repeated testing carried over the course of 12 months, little to no eye irritation was detected. TG fluctuations over time visually appeared to trace the same pattern as BG with an average lag times of 13 minutes. TG levels calculated from the device current measurements ranged from 4 to 20 mg/dL and correlated linearly with BG levels of 75-160 mg/dL (TG = 0.1723 BG = 7.9448 mg/dL; R 2 = .7544). The first steps were taken toward preliminary development of a sensor for self-monitoring of tear glucose (SMTG). No conjunctival irritation in any of the animals was noted. Lag time between TG and BG was found to be noticeable, but a quantitative modeling to correlate lag time in this study is unnecessary. Measured currents from the sensors and the calculated TG showed promising correlation to BG levels. Previous analytical bench marking showed BG and TG levels consistent with other literature. © 2014 Diabetes Technology Society.

Preventing exercise-induced hypoglycemia in type 1 diabetes using real-time continuous glucose monitoring and a new carbohydrate intake algorithm: an observational field study.

PubMed

Riddell, Michael C; Milliken, Jill

2011-08-01

Real-time (RT) continuous glucose monitoring (CGM) offers the possibility to better manage glucose levels during exercise in active individuals with type 1 diabetes mellitus (T1DM). However, studies have yet to determine the appropriate actions to take when glucose levels are trending toward hypoglycemia. The purpose of this observational field study was to test the effectiveness of RT-GCM and a new carbohydrate intake algorithm designed for maintaining euglycemia during sports. During a 2-week sports camp, 25 adolescents (8-17 years old) with T1DM were fitted with a RT-CGM device and instructed to ingest fast-acting carbohydrates (8-20 g, depending on the concentration of glucose at the time of RT-CGM alert and rates of change in glycemia) when glucose levels were trending toward hypoglycemia. Rates of change in glucose were measured before and after algorithm use, and the incidence of hypoglycemia was documented. With RT-CGM and algorithm use, euglycemia was largely maintained with modest amounts of carbohydrate intake, even when glucose levels were initially dropping at an elevated rate (>0.55 mmol/L per 5 min). Mild biochemical hypoglycemia (3.0-3.9 mmol/L) occurred just twice out of 22 uses of the algorithm (9%) when trend arrows alerted the subjects that glucose levels were dropping. When glucose levels were already below target (<5.0 mmol/L), mild hypoglycemia occurred five times out of 13 events (38%), despite 16 g of carbohydrate being ingested. Average glucose levels during sports in the 60 min following algorithm use were 5.8 ± 1.2 mmol/L, 5.3 ± 1.0 mmol/L, and 6.2 ± 0.8 mmol/L in the 20-, 16-, and 8-g carbohydrate intake protocols when glucose levels were initially on target but dropping toward hypoglycemia. When coupled with RT-CGM, a new carbohydrate intake algorithm prevents hypoglycemia and maintains euglycemia during exercise, particularly if patients ingest carbohydrate when trend arrows alert them of a drop in glycemia.

Continuous Glucose Monitoring

MedlinePlus

... transmit- ter sends information about glucose levels via radio waves from the sensor to a pagerlike wireless ... 703–738–4929 Email: ndep@mail.nih.gov Internet: www.ndep.nih.gov American Diabetes Association 1701 ...

A new application of electrical impedance spectroscopy for measuring glucose metabolism: a phantom study

NASA Astrophysics Data System (ADS)

Dhurjaty, Sreeram; Qiu, Yuchen; Tan, Maxine; Liu, Hong; Zheng, Bin

2015-03-01

Glucose metabolism relates to biochemical processes in living organisms and plays an important role in diabetes and cancer-metastasis. Although many methods are available for measuring glucose metabolism-activities, from simple blood tests to positron emission tomography, currently there is no robust and affordable device that enables monitoring of glucose levels in real-time. In this study we tested feasibility of applying a unique resonance-frequency based electronic impedance spectroscopy (REIS) device that has been, recently developed to measure and monitor glucose metabolism levels using a phantom study. In this new testing model, a multi-frequency electrical signal sequence is applied and scanned through the subject. When the positive reactance of an inductor inside the device cancels out the negative reactance of the capacitance of the subject, the electrical impedance reaches a minimum value and this frequency is defined as the resonance frequency. The REIS system has a 24-bit analog-to-digital signal convertor and a frequency-resolution of 100Hz. In the experiment, two probes are placed inside a 100cc container initially filled with distilled water. As we gradually added liquid-glucose in increments of 1cc (250mg), we measured resonance frequencies and minimum electrical signal values (where A/D was normalized to a full scale of 1V). The results showed that resonance frequencies monotonously decreased from 243kHz to 178kHz, while the minimum voltages increased from 405mV to 793mV as the added amount of glucose increased from 0 to 5cc. The study demonstrated the feasibility of applying this new REIS technology to measure and/or monitor glucose levels in real-time in future.

Precision and costs of techniques for self-monitoring of serum glucose levels.

PubMed Central

Chiasson, J. L.; Morrisset, R.; Hamet, P.

1984-01-01

The poor correlation between serum and urine glucose measurements has led to the development of new techniques for monitoring the blood glucose level in diabetic patients. Either a nurse or the patient can perform these tests, which involve spreading a single drop of blood onto a reagent strip. A colour change that is proportional to the serum glucose level can be read visually or with a reflectance meter. Evaluated against simultaneous serum glucose levels determined by the hospital biochemistry laboratory, those of the new techniques employing reflectance meters all showed excellent correlation (r2 = 0.85 to 0.96). Reagent strips used without meters showed poorer correlation (r2 = 0.69 to 0.90). The instruction given to the patients and one nurse enabled them to obtain more accurate results with one of the meters than nurses not specially trained (r2 = 0.94 and 0.92 v. 0.85 respectively). The mean cost per glucose determination with the new techniques was 75, compared with +1.45 for the laboratory determinations done with automated equipment. It was concluded that the new techniques compared well with the reference method, particularly when reflectance meters were used, and that they were easily applied by the patient, as well as the medical staff, at a reasonable cost. PMID:6689988

Recent Advances in Fluorescent Arylboronic Acids for Glucose Sensing

PubMed Central

Hansen, Jon Stefan; Christensen, Jørn Bolstad

2013-01-01

Continuous glucose monitoring (CGM) is crucial in order to avoid complications caused by change in blood glucose for patients suffering from diabetes mellitus. The long-term consequences of high blood glucose levels include damage to the heart, eyes, kidneys, nerves and other organs, among others, caused by malign glycation of vital protein structures. Fluorescent monitors based on arylboronic acids are promising candidates for optical CGM, since arylboronic acids are capable of forming arylboronate esters with 1,2-cis-diols or 1,3-diols fast and reversibly, even in aqueous solution. These properties enable arylboronic acid dyes to provide immediate information of glucose concentrations. Thus, the replacement of the commonly applied semi-invasive and non-invasive techniques relying on glucose binding proteins, such as concanavalin A, or enzymes, such as glucose oxidase, glucose dehydrogenase and hexokinases/glucokinases, might be possible. The recent progress in the development of fluorescent arylboronic acid dyes will be emphasized in this review. PMID:25586415

A Low-Cost Inkjet-Printed Glucose Test Strip System for Resource-Poor Settings.

PubMed

Gainey Wilson, Kayla; Ovington, Patrick; Dean, Delphine

2015-06-12

The prevalence of diabetes is increasing in low-resource settings; however, accessing glucose monitoring is extremely difficult and expensive in these regions. Work is being done to address the multitude of issues surrounding diabetes care in low-resource settings, but an affordable glucose monitoring solution has yet to be presented. An inkjet-printed test strip solution is being proposed as a solution to this problem. The use of a standard inkjet printer is being proposed as a manufacturing method for low-cost glucose monitoring test strips. The printer cartridges are filled with enzyme and dye solutions that are printed onto filter paper. The result is a colorimetric strip that turns a blue/green color in the presence of blood glucose. Using a light-based spectroscopic reading, the strips show a linear color change with an R(2) = .99 using glucose standards and an R(2) = .93 with bovine blood. Initial testing with bovine blood indicates that the strip accuracy is comparable to the International Organization for Standardization (ISO) standard 15197 for glucose testing in the 0-350 mg/dL range. However, further testing with human blood will be required to confirm this. A visible color gradient was observed with both the glucose standard and bovine blood experiment, which could be used as a visual indicator in cases where an electronic glucose meter was unavailable. These results indicate that an inkjet-printed filter paper test strip is a feasible method for monitoring blood glucose levels. The use of inkjet printers would allow for local manufacturing to increase supply in remote regions. This system has the potential to address the dire need for glucose monitoring in low-resource settings. © 2015 Diabetes Technology Society.

Evaluation of a novel continuous glucose measurement device in patients with diabetes mellitus across the glycemic range.

PubMed

Morrow, Linda; Hompesch, Marcus; Tideman, Ann M; Matson, Jennifer; Dunne, Nancy; Pardo, Scott; Parkes, Joan L; Schachner, Holly C; Simmons, David A

2011-07-01

This glucose clamp study assessed the performance of an electrochemical continuous glucose monitoring (CGM) system for monitoring levels of interstitial glucose. This novel system does not require use of a trocar or needle for sensor insertion. Continuous glucose monitoring sensors were inserted subcutaneously into the abdominal tissue of 14 adults with type 1 or type 2 diabetes. Subjects underwent an automated glucose clamp procedure with four consecutive post-steady-state glucose plateau periods (40 min each): (a) hypoglycemic (50 mg/dl), (b) hyperglycemic (250 mg/dl), (c) second hypoglycemic (50 mg/dl), and (d) euglycemic (90 mg/dl). Plasma glucose results obtained with YSI glucose analyzers were used for sensor calibration. Accuracy was assessed retrospectively for plateau periods and transition states, when glucose levels were changing rapidly (approximately 2 mg/dl/min). Mean absolute percent difference (APD) was lowest during hypoglycemic plateaus (11.68%, 14.15%) and the euglycemic-to-hypoglycemic transition (14.21%). Mean APD during the hyperglycemic plateau was 17.11%; mean APDs were 18.12% and 19.25% during the hypoglycemic-to-hyperglycemic and hyperglycemic-to-hypoglycemic transitions, respectively. Parkes (consensus) error grid analysis (EGA) and rate EGA of the plateaus and transition periods, respectively, yielded 86.8% and 68.6% accurate results (zone A) and 12.1% and 20.0% benign errors (zone B). Continuous EGA yielded 88.5%, 75.4%, and 79.3% accurate results and 8.3%, 14.3%, and 2.4% benign errors for the euglycemic, hyperglycemic, and hypoglycemic transition periods, respectively. Adverse events were mild and unlikely to be device related. This novel CGM system was safe and accurate across the clinically relevant glucose range. © 2011 Diabetes Technology Society.

Evaluation of a Novel Continuous Glucose Measurement Device in Patients with Diabetes Mellitus across the Glycemic Range

PubMed Central

Morrow, Linda; Hompesch, Marcus; Tideman, Ann M; Matson, Jennifer; Dunne, Nancy; Pardo, Scott; Parkes, Joan L; Schachner, Holly C; Simmons, David A

2011-01-01

Background This glucose clamp study assessed the performance of an electrochemical continuous glucose monitoring (CGM) system for monitoring levels of interstitial glucose. This novel system does not require use of a trocar or needle for sensor insertion. Method Continuous glucose monitoring sensors were inserted subcutaneously into the abdominal tissue of 14 adults with type 1 or type 2 diabetes. Subjects underwent an automated glucose clamp procedure with four consecutive post-steady-state glucose plateau periods (40 min each): (a) hypoglycemic (50 mg/dl), (b) hyperglycemic (250 mg/dl), (c) second hypoglycemic (50 mg/dl), and (d) euglycemic (90 mg/dl). Plasma glucose results obtained with YSI glucose analyzers were used for sensor calibration. Accuracy was assessed retrospectively for plateau periods and transition states, when glucose levels were changing rapidly (approximately 2 mg/dl/min). Results Mean absolute percent difference (APD) was lowest during hypoglycemic plateaus (11.68%, 14.15%) and the euglycemic-to-hypoglycemic transition (14.21%). Mean APD during the hyperglycemic plateau was 17.11%; mean APDs were 18.12% and 19.25% during the hypoglycemic-to-hyperglycemic and hyperglycemic-to-hypoglycemic transitions, respectively. Parkes (consensus) error grid analysis (EGA) and rate EGA of the plateaus and transition periods, respectively, yielded 86.8% and 68.6% accurate results (zone A) and 12.1% and 20.0% benign errors (zone B). Continuous EGA yielded 88.5%, 75.4%, and 79.3% accurate results and 8.3%, 14.3%, and 2.4% benign errors for the euglycemic, hyperglycemic, and hypoglycemic transition periods, respectively. Adverse events were mild and unlikely to be device related. Conclusion This novel CGM system was safe and accurate across the clinically relevant glucose range. PMID:21880226

Association between blood glucose level derived using the oral glucose tolerance test and glycated hemoglobin level.

PubMed

Kim, Hyoung Joo; Kim, Young Geon; Park, Jin Soo; Ahn, Young Hwan; Ha, Kyoung Hwa; Kim, Dae Jung

2016-05-01

Glycated hemoglobin (HbA1c) is widely used as a marker of glycemic control. Translation of the HbA1c level to an average blood glucose level is useful because the latter figure is easily understood by patients. We studied the association between blood glucose levels revealed by the oral glucose tolerance test (OGTT) and HbA1c levels in a Korean population. A total of 1,000 subjects aged 30 to 64 years from the Cardiovascular and Metabolic Diseases Etiology Research Center cohort were included. Fasting glucose levels, post-load glucose levels at 30, 60, and 120 minutes into the OGTT, and HbA1c levels were measured. Linear regression of HbA1c with mean blood glucose levels derived using the OGTT revealed a significant correlation between these measures (predicted mean glucose [mg/dL] = 49.4 × HbA1c [%] - 149.6; R (2) = 0.54, p < 0.001). Our linear regression equation was quite different from that of the Alc-Derived Average Glucose (ADAG) study and Diabetes Control and Complications Trial (DCCT) cohort. Discrepancies between our results and those of the ADAG study and DCCT cohort may be attributable to differences in the test methods used and the extent of insulin secretion. More studies are needed to evaluate the association between HbA1c and self monitoring blood glucose levels.

Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

PubMed Central

Mortazavi, SMJ; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, AR

2014-01-01

Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors. PMID:25505778

Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors.

PubMed

Mortazavi, Smj; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, Ar

2014-09-01

Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors.

The Effects of Mitiglinide and Repaglinide on Postprandial Hyperglycemia in Patients Undergoing Methylprednisolone Pulse Therapy.

PubMed

Tanaka, Kenichi; Okada, Yosuke; Mori, Hiroko; Torimoto, Keiichi; Arao, Tadashi; Tanaka, Yoshiya

2018-01-01

One adverse effect of methylprednisolone (MP) pulse therapy is an acute dose-dependent increase in the blood glucose level. Five patients with thyroid ophthalmopathy but normal glucose tolerance received MP pulse therapy (3 cycles, 3 days/week) and were assessed by continuous glucose monitoring. Steroid therapy increased the mean sensor glucose level, and all patients developed steroid-induced diabetes. The patients were treated alternately with mitiglinide (30 mg/day) and repaglinide (1.5 mg/day) during the second or third MP pulse therapy. The sensor glucose levels before lunch and dinner were more favorable during treatment with repaglinide than during treatment with mitiglinide. Repaglinide may be more clinically appropriate than mitiglinide.

Gaussian Process modelling of blood glucose response to free-living physical activity data in people with type 1 diabetes.

PubMed

Valletta, John Joseph; Chipperfield, Andrew J; Byrne, Christopher D

2009-01-01

Good blood glucose control is important to people with type 1 diabetes to prevent diabetes-related complications. Too much blood glucose (hyperglycaemia) causes long-term micro-vascular complications, while a severe drop in blood glucose (hypoglycaemia) can cause life-threatening coma. Finding the right balance between quantity and type of food intake, physical activity levels and insulin dosage, is a daily challenge. Increased physical activity levels often cause changes in blood glucose due to increased glucose uptake into tissues such as muscle. To date we have limited knowledge about the minute by minute effects of exercise on blood glucose levels, in part due to the difficulty in measuring glucose and physical activity levels continuously, in a free-living environment. By using a light and user-friendly armband we can record physical activity energy expenditure on a minute-by-minute basis. Simultaneously, by using a continuous glucose monitoring system we can record glucose concentrations. In this paper, Gaussian Processes are used to model the glucose excursions in response to physical activity data, to study its effect on glycaemic control.

Noninvasive biosensor and wireless interrogating system for glucose in blood

NASA Astrophysics Data System (ADS)

Varadan, Vijay K.; Whitchurch, Ashwin K.; Sarukesi, K.

2003-07-01

Hypoglycemia-abnormal decrease in blood sugar-is a major obstacle in the management of diabetes and prevention of long-term complications, and it may impose serious effects on the brain, including impairment of memory and other cognitive functions. This paper presents the development of a non-invasive sensor with miniaturized telemetry device in a wrist-watch for monitoring glucose concentration in blood. The sensor concept is based on optical chirality of glucose level in the interstitial fluid. The wrist watch consists of a laser power source of the wavelength compatible with the glucose. A nanofilm with specific chirality is placed at the bottom of the watch. The light then passes through the film and illuminates a small area on the skin. It has been documented that there is certain concentration of sugar level is taken by the intertitial fluid from the blood stream and deposit a portion of it at the dead skin. The wrist-watch when in contact with the outer skin of the human will thus monitor the glucose concentration. A wireless monitoring system in the watch then downloads the data from the watch to a Palm or a laptop computer.

Current concepts in blood glucose monitoring

PubMed Central

Khadilkar, Kranti Shreesh; Bandgar, Tushar; Shivane, Vyankatesh; Lila, Anurag; Shah, Nalini

2013-01-01

Blood glucose monitoring has evolved over the last century. The concept of adequate glycemic control and minimum glycemic variability requires an ideal, accurate and reliable glucose monitoring system. The search for an ideal blood glucose monitoring system still continues. This review explains the various blood glucose monitoring systems with special focus on the monitoring systems like self- monitored blood glucose (SMBG) and continuous glucose monitoring system (CGMS). It also focuses on the newer concepts of blood glucose monitoring and their incorporation in routine clinical management of diabetes mellitus. PMID:24910827

Sensing of Salivary Glucose Using Nano-Structured Biosensors

PubMed Central

Du, Yunqing; Zhang, Wenjun; Wang, Ming L.

2016-01-01

The anxiety and pain associated with frequent finger pricking has always been troublesome for diabetics measuring blood glucose (BG) in their daily lives. For this reason, a reliable glucose monitoring system that allows noninvasive measurements is highly desirable. Our main objective is to develop a biosensor that can detect low-level glucose in saliva (physiological range 0.5–20 mg/dL). Salivary glucose (SG) sensors were built using a layer-by-layer self-assembly of single-walled carbon nanotubes, chitosan, gold nanoparticles, and glucose oxidase onto a screen-printed platinum electrode. An electrochemical method was utilized for the quantitative detection of glucose in both buffer solution and saliva samples. A standard spectrophotometric technique was used as a reference method to validate the glucose content of each sample. The disposable glucose sensors have a detection limit of 0.41 mg/dL, a sensitivity of 0.24 μA·s·dL·mg−1, a linear range of 0.5–20 mg/dL in buffer solution, and a response time of 30 s. A study of 10 healthy subjects was conducted, and SG levels between 1.1 to 10.1 mg/dL were successfully detected. The results revealed that the noninvasive SG monitoring could be an alternative for diabetes self-management at home. This paper is not intended to replace regular BG tests, but to study SG itself as an indicator for the quality of diabetes care. It can potentially help patients control and monitor their health conditions, enabling them to comply with prescribed treatments for diabetes. PMID:26999233

Sensing of Salivary Glucose Using Nano-Structured Biosensors.

PubMed

Du, Yunqing; Zhang, Wenjun; Wang, Ming L

2016-03-17

The anxiety and pain associated with frequent finger pricking has always been troublesome for diabetics measuring blood glucose (BG) in their daily lives. For this reason, a reliable glucose monitoring system that allows noninvasive measurements is highly desirable. Our main objective is to develop a biosensor that can detect low-level glucose in saliva (physiological range 0.5-20 mg/dL). Salivary glucose (SG) sensors were built using a layer-by-layer self-assembly of single-walled carbon nanotubes, chitosan, gold nanoparticles, and glucose oxidase onto a screen-printed platinum electrode. An electrochemical method was utilized for the quantitative detection of glucose in both buffer solution and saliva samples. A standard spectrophotometric technique was used as a reference method to validate the glucose content of each sample. The disposable glucose sensors have a detection limit of 0.41 mg/dL, a sensitivity of 0.24 μA·s·dL·mg(-1), a linear range of 0.5-20 mg/dL in buffer solution, and a response time of 30 s. A study of 10 healthy subjects was conducted, and SG levels between 1.1 to 10.1 mg/dL were successfully detected. The results revealed that the noninvasive SG monitoring could be an alternative for diabetes self-management at home. This paper is not intended to replace regular BG tests, but to study SG itself as an indicator for the quality of diabetes care. It can potentially help patients control and monitor their health conditions, enabling them to comply with prescribed treatments for diabetes.

Continuous glucose monitoring reveals different glycemic responses of moderate- vs high-carbohydrate lunch meals in people with type 2 diabetes.

PubMed

Powers, Margaret A; Cuddihy, Robert M; Wesley, David; Morgan, Blaine

2010-12-01

This single-center, meal-intervention, crossover study was conducted to determine the glycemic response to fixed meals with varying carbohydrate content. Continuous glucose monitoring was used to document the glycemic response. Participants were 14 people with type 2 diabetes on metformin only. On 4 consecutive days in March or July 2008, study participants consumed a fixed breakfast and one of two test meals (lunch) provided in random order. The two lunch types varied only in carbohydrate content; the protein, fat, fiber, and glycemic index were similar. They consumed no caloric food or beverages for 4 hours after each meal. Consuming double the carbohydrate content did not double the glycemic response variables, yet most were substantially different in glucose value (mg/dL) or minutes. General linear model analyses revealed substantial differences for peak glucose, change from baseline glucose to peak, time to return to preprandial glucose, 4-hour glucose area under the curve, and 4-hour mean glucose. Continuous glucose monitoring data provided a robust description of the glycemic response to the two meals. Such data can help improve postprandial glucose levels through more informed nutrition recommendations and synchronization of food intake, diabetes medication, and/or physical activity. Copyright © 2010 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

Efficacy and safety of teneligliptin in addition to insulin therapy in type 2 diabetes mellitus patients on hemodialysis evaluated by continuous glucose monitoring.

PubMed

Yajima, Takahiro; Yajima, Kumiko; Hayashi, Makoto; Takahashi, Hiroshi; Yasuda, Keigo

2016-12-01

Appropriate glycemic control without hypoglycemia is important in patients with type 2 diabetes on hemodialysis. Teneligliptin, a novel dipeptidyl peptidase-4 inhibitor, can be used without dose adjustment for these patients. Using continuous glucose monitoring (CGM), we evaluated the efficacy and safety of adding teneligliptin to insulin therapy. Twenty-one type 2 diabetes mellitus patients on hemodialysis treated with insulin were enrolled. After the adjustment of insulin dose, their blood glucose level was monitored by CGM. Insulin dose was reduced after teneligliptin administration. The median total daily insulin dose significantly reduced from 18 (9-24)U to 6 (0-14)U (p<0.0001). Maximum, mean, and standard deviation of blood glucose level on the hemodialysis and non-hemodialysis days did not change after teneligliptin administration. However, minimum blood glucose level was significantly elevated on the hemodialysis day after teneligliptin administration (from 3.9±1.0mmol/L to 4.4±0.9mmol/L, p=0.040). The incidence of asymptomatic hypoglycemia on the hemodialysis day detected by CGM significantly decreased from 38.1% to 19.0% (p=0.049). Teneligliptin may contribute toward reducing the total daily insulin dose and preventing hypoglycemic events on the hemodialysis day in type 2 diabetes mellitus patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The self-aware diabetic patient software agent model.

PubMed

Wang, Zhanle; Paranjape, Raman

2013-11-01

This work presents a self-aware diabetic patient software agent for representing a human diabetic patient. To develop a 24h, stochastic and self-aware patient agent, we extend the original seminal work of Ackerman et al. [1] in creating a mathematical model of human blood glucose levels in three aspects. (1) We incorporate the stochastic and unpredictable effects of daily living. (2) The Ackerman model is extended into the period of night-time. (3) Patients' awareness of their own conditions is incorporated. Simulation results are quantitatively assessed to demonstrate the effectiveness of lifestyle management, such as adjusting the amount of food consumed, meal schedule, intensity of exercise and level of medication. In this work we show through the simulation that the average blood glucose can be reduced by as much as 51% due to careful lifestyle management. Self monitoring blood glucose is also quantitatively evaluated. The simulation results show that the average blood glucose is further dropped by 25% with the assistance of blood glucose samples. In addition, the blood glucose is perfectly controlled in the target range during the simulation period as a result of joint efforts of lifestyle management and self monitoring blood glucose. This study focuses on demonstrating how human patients' behavior, specifically lifestyle and self monitoring of blood glucose, affects blood glucose controls on a daily basis. This work does not focus on the insulin-glucose interaction of an individual human patient. Our conclusion is that this self-aware patient agent model is capable of adequately representing diabetic patients and of evaluating their dynamic behaviors. It can also be incorporated into a multi-agent system by introducing other healthcare components so that more interesting insights such as the healthcare quality, cost and performance can be observed. © 2013 Published by Elsevier Ltd.

Higher Fasting Plasma Glucose Levels, within the Normal Range, are Associated with Decreased Processing Speed in High Functioning Young Elderly.

PubMed

Raizes, Meytal; Elkana, Odelia; Franko, Motty; Ravona Springer, Ramit; Segev, Shlomo; Beeri, Michal Schnaider

2016-01-01

We explored the association of plasma glucose levels within the normal range with processing speed in high functioning young elderly, free of type 2 diabetes mellitus (T2DM). A sample of 41 participants (mean age = 64.7, SD = 10; glucose 94.5 mg/dL, SD = 9.3), were examined with a computerized cognitive battery. Hierarchical linear regression analysis showed that higher plasma glucose levels, albeit within the normal range (<110 mg/dL), were associated with longer reaction times (p <  0.01). These findings suggest that even in the subclinical range and in the absence of T2DM, monitoring plasma glucose levels may have an impact on cognitive function.

Clinical update on optimal prandial insulin dosing using a refined run-to-run control algorithm.

PubMed

Zisser, Howard; Palerm, Cesar C; Bevier, Wendy C; Doyle, Francis J; Jovanovic, Lois

2009-05-01

This article provides a clinical update using a novel run-to-run algorithm to optimize prandial insulin dosing based on sparse glucose measurements from the previous day's meals. The objective was to use a refined run-to-run algorithm to calculate prandial insulin-to-carbohydrate ratios (I:CHO) for meals of variable carbohydrate content in subjects with type 1 diabetes (T1DM). The open-labeled, nonrandomized study took place over a 6-week period in a nonprofit research center. Nine subjects with T1DM using continuous subcutaneous insulin infusion participated. Basal insulin rates were optimized using continuous glucose monitoring, with a target fasting blood glucose of 90 mg/dl. Subjects monitored blood glucose concentration at the beginning of the meal and at 60 and 120 minutes after the start of the meal. They were instructed to start meals with blood glucose levels between 70 and 130 mg/dl. Subjects were contacted daily to collect data for the previous 24-hour period and to give them the physician-approved, algorithm-derived I:CHO ratios for the next 24 hours. Subjects calculated the amount of the insulin bolus for each meal based on the corresponding I:CHO and their estimate of the meal's carbohydrate content. One- and 2-hour postprandial glucose concentrations served as the main outcome measures. The mean 1-hour postprandial blood glucose level was 104 +/- 19 mg/dl. The 2-hour postprandial levels (96.5 +/- 18 mg/dl) approached the preprandial levels (90.1 +/- 13 mg/dl). Run-to-run algorithms are able to improve postprandial blood glucose levels in subjects with T1DM. 2009 Diabetes Technology Society.

A human pilot study of the fluorescence affinity sensor for continuous glucose monitoring in diabetes.

PubMed

Dutt-Ballerstadt, Ralph; Evans, Colton; Pillai, Arun P; Orzeck, Eric; Drabek, Rafal; Gowda, Ashok; McNichols, Roger

2012-03-01

We report results of a pilot clinical study of a subcutaneous fluorescence affinity sensor (FAS) for continuous glucose monitoring conducted in people with type 1 and type 2 diabetes. The device was assessed based on performance, safety, and comfort level under acute conditions (4 h). A second-generation FAS (BioTex Inc., Houston, TX) was subcutaneously implanted in the abdomens of 12 people with diabetes, and its acute performance to excursions in blood glucose was monitored over 4 h. After 30-60 min the subjects, who all had fasting blood glucose levels of less than 200 mg/dl, received a glucose bolus of 75 g/liter dextrose by oral administration. Capillary blood glucose samples were obtained from the finger tip. The FAS data were retrospectively evaluated by linear least squares regression analysis and by the Clarke error grid method. Comfort levels during insertion, operation, and sensor removal were scored by the subjects using an analog pain scale. After retrospective calibration of 17 sensors implanted in 12 subjects, error grid analysis showed 97% of the paired values in zones A and B and 1.5% in zones C and D, respectively. The mean absolute relative error between sensor signal and capillary blood glucose was 13% [±15% standard deviation (SD), 100-350 mg/dl] with an average correlation coefficient of 0.84 (±0.24 SD). The actual average "warm-up" time for the FAS readings, at which highest correlation with glucose readings was determined, was 65 (±32 SD) min. Mean time lag was 4 (±5 SD) min during the initial operational hours. Pain levels during insertion and operation were modest. The in vivo performance of the FAS demonstrates feasibility of the fluorescence affinity technology to determine blood glucose excursions accurately and safely under acute dynamic conditions in humans with type 1 and type 2 diabetes. Specific engineering challenges to sensor and instrumentation robustness remain. Further studies will be required to validate its promising performance over longer implantation duration (5-7 days) in people with diabetes. © 2012 Diabetes Technology Society.

Detection of hypoglycemia with continuous interstitial and traditional blood glucose monitoring using the FreeStyle Navigator Continuous Glucose Monitoring System.

PubMed

McGarraugh, Geoffrey; Bergenstal, Richard

2009-03-01

The objective of the analysis was to compare detection of hypoglycemic episodes (glucose <70 mg/dL lasting >15 min) with the FreeStyle Navigator Continuous Glucose Monitoring System (FSN-CGM) (Abbott Diabetes Care, Alameda, CA) alarms to detection with traditional finger stick testing at an average frequency of eight tests per day. The performance of FSN-CGM alarms was evaluated in a clinic setting using 58 subjects with type 1 diabetes mellitus (T1DM) monitoring interstitial glucose concentration over a 5-day period compared to reference YSI measurements (instrument manufactured by YSI, Yellow Springs, OH) at 15-min intervals. Finger stick glucose testing was evaluated in the home environment with 91 subjects with TIDM monitoring with the blood glucose meter integrated into the FreeStyle Navigator (FSN-BG) over a 20-day period. The reference was FSN-CGM with results masked from the subjects. Blood glucose values <=85 mg/dL were considered the optimal treatment level to avoid or reverse hypoglycemia. With a threshold alarm setting of 85 mg/dL, 90.6% of hypoglycemic episodes were detected within +/- 30 min by FSN-CGM in the clinic study. When the alarm was activated, YSI glucose was <= 85 mg/dL 77.2% of the time. In the home environment, the average FSN-BG testing frequency was 7.9 tests per day. Hypoglycemia was verified within +/- 30 min by FSN-BG measurements <= 85 mg/dL at a rate of 27.5%. Even with a high rate of FSN-BG testing, hypoglycemia detected by FSN-CGM was verified by patients with T1DM very infrequently. A high rate of hypoglycemia detection with a moderate rate of unnecessary alarms can be attained using FSN-CGM.

Transmission of hepatitis B virus among persons undergoing blood glucose monitoring in long-term-care facilities--Mississippi, North Carolina, and Los Angeles County, California, 2003-2004.

PubMed

2005-03-11

Regular monitoring of blood glucose levels is an important component of routine diabetes care. Capillary blood is typically sampled with the use of a fingerstick device and tested with a portable glucometer. Because of outbreaks of hepatitis B virus (HBV) infections associated with glucose monitoring, CDC and the Food and Drug Administration (FDA) have recommended since 1990 that fingerstick devices be restricted to individual use. This report describes three recent outbreaks of HBV infection among residents in long-term-care (LTC) facilities that were attributed to shared devices and other breaks in infection-control practices related to blood glucose monitoring. Findings from these investigations and previous reports suggest that recommendations concerning standard precautions and the reuse of fingerstick devices have not been adhered to or enforced consistently in LTC settings. The findings underscore the need for education, training, adherence to standard precautions, and specific infection-control recommendations targeting diabetes-care procedures in LTC settings.

The Design and Development of Fluorescent Nano-Optodes for in Vivo Glucose Monitoring

PubMed Central

Balaconis, Mary K.; Billingsley, Kelvin; Dubach, J. Matthew; Cash, Kevin J.; Clark, Heather A.

2011-01-01

Background The advent of fluorescent nanosensors has enabled intracellular monitoring of several physiological analytes, which was previously not possible with molecular dyes or other invasive techniques. We have extended the capability of these sensors to include the detection of small molecules with the development of glucose-sensitive nano-optodes. Herein, we discuss the design and development of glucose-sensitive nano-optodes, which have been proven functional both in vitro and in vivo. Methods Throughout the design process, each of the sensor formulations was evaluated based on their response to changes in glucose levels. The percent change in signal, sensor reversibility, and the overall fluorescence intensity were the specific parameters used to assess each formulation. Results A hydrophobic boronic acid was selected that yielded a fully reversible fluorescence response to glucose in accordance with the sensor mechanism. The change in fluorescence signal in response to glucose was approximately 11%. The use of different additives or chromophores did not improve the response; however, modifications to the plasticized polymeric membrane extended sensor lifetime. Conclusions Sensors were developed that yielded a dynamic response to glucose and through further modification of the components, sensor lifetime was improved. By following specific design criteria for the macrosensors, the sensors were miniaturized into nano-optodes that track changes in glucose levels in vivo. PMID:21303627

The design and development of fluorescent nano-optodes for in vivo glucose monitoring.

PubMed

Balaconis, Mary K; Billingsley, Kelvin; Dubach, Matthew J; Cash, Kevin J; Clark, Heather A

2011-01-01

The advent of fluorescent nanosensors has enabled intracellular monitoring of several physiological analytes, which was previously not possible with molecular dyes or other invasive techniques. We have extended the capability of these sensors to include the detection of small molecules with the development of glucose-sensitive nano-optodes. Herein, we discuss the design and development of glucose-sensitive nano-optodes, which have been proven functional both in vitro and in vivo. Throughout the design process, each of the sensor formulations was evaluated based on their response to changes in glucose levels. The percent change in signal, sensor reversibility, and the overall fluorescence intensity were the specific parameters used to assess each formulation. A hydrophobic boronic acid was selected that yielded a fully reversible fluorescence response to glucose in accordance with the sensor mechanism. The change in fluorescence signal in response to glucose was approximately 11%. The use of different additives or chromophores did not improve the response; however, modifications to the plasticized polymeric membrane extended sensor lifetime. Sensors were developed that yielded a dynamic response to glucose and through further modification of the components, sensor lifetime was improved. By following specific design criteria for the macrosensors, the sensors were miniaturized into nano-optodes that track changes in glucose levels in vivo. © 2010 Diabetes Technology Society.

Options for the Development of Noninvasive Glucose Monitoring: Is Nanotechnology an Option to Break the Boundaries?

PubMed

Thomas, Andreas; Heinemann, Lutz; Ramírez, Araceli; Zehe, Alfred

2016-05-01

Nowadays nanotechnology has many applications in products used in various areas of daily life; however, this technology has also an option in modern medicine and pharmacy. Therefore, this technology is also an attractive option for the field of diagnosis and treatment of diabetes. Many people with diabetes measure their blood glucose levels regularly to determine the insulin dose. Ideally glucose values would be measured noninvasively (NI). However, none of all the NI approaches studied in the past decades enabled reliable NI measurements under all daily life conditions. Particularly an unfavorable signal-to-noise ratio turned out to be problematic. Based on the known physical possibilities for NI glucose monitoring the focus of this review is on nanotechnology approaches. Functional prototypes exist for some of these that showed promising results under defined laboratory conditions, indicating a good sensitivity and selectivity for glucose. On the second hand is to optimize the technological process of manufacturing. In view of the rapid progress in micro- and nanoelectronics hopefully NI glucose monitoring systems can be developed in the near future. © 2015 Diabetes Technology Society.

Options for the Development of Noninvasive Glucose Monitoring

PubMed Central

Thomas, Andreas; Heinemann, Lutz; Ramírez, Araceli; Zehe, Alfred

2015-01-01

Nowadays nanotechnology has many applications in products used in various areas of daily life; however, this technology has also an option in modern medicine and pharmacy. Therefore, this technology is also an attractive option for the field of diagnosis and treatment of diabetes. Many people with diabetes measure their blood glucose levels regularly to determine the insulin dose. Ideally glucose values would be measured noninvasively (NI). However, none of all the NI approaches studied in the past decades enabled reliable NI measurements under all daily life conditions. Particularly an unfavorable signal-to-noise ratio turned out to be problematic. Based on the known physical possibilities for NI glucose monitoring the focus of this review is on nanotechnology approaches. Functional prototypes exist for some of these that showed promising results under defined laboratory conditions, indicating a good sensitivity and selectivity for glucose. On the second hand is to optimize the technological process of manufacturing. In view of the rapid progress in micro- and nanoelectronics hopefully NI glucose monitoring systems can be developed in the near future. PMID:26581879

An On-Chip Disposable Salivary Glucose Sensor for Diabetes Control.

PubMed

Du, Yunqing; Zhang, Wenjun; Wang, Ming L

2016-11-01

Self-management of blood glucose (BG) is considered a norm for diabetes control. However, this invasive process is uncomfortable for patients, especially when intensive measurements with frequent finger pricks are required. Saliva, an alternative body fluid that is easily accessible and contains trace amount of glucose can be potentially used for the noninvasive monitoring of diabetes. As a solution for real-time glucose measurements using saliva for diabetic care, we have developed an on-chip disposable glucose nano-biosensor through a layer-by-layer assembly process. In this work, a clinical study of 10 healthy subjects was conducted to determine the potential usefulness of salivary glucose (SG) sensors for glycemic control. Findings revealed (1) the individual BG/SG ratio at fasting was consistent over an entire year when there was no significant change of personal health; (2) the individual SG levels tracked closely with BG levels after meals; (3) a time difference of 15-30 minutes exists between peak levels of BG and SG; (4) 2 hours after a meal, the BG/SG ratio returned to a similar value at fasting. We propose to measure fasting and pre- and 2-hour postprandial SG levels for self-management of glycemic levels. As a result, this article is not intended to replace the common BG tests. With preliminary results, we believe SG itself could be used as means for reliable diabetes monitoring and a potential fluid for prognosis of future disease. © 2016 Diabetes Technology Society.

A Human Serum-Based Enzyme-Free Continuous Glucose Monitoring Technique Using a Needle-Type Bio-Layer Interference Sensor.

PubMed

Seo, Dongmin; Paek, Sung-Ho; Oh, Sangwoo; Seo, Sungkyu; Paek, Se-Hwan

2016-09-24

The incidence of diabetes is continually increasing, and by 2030, it is expected to have increased by 69% and 20% in underdeveloped and developed countries, respectively. Therefore, glucose sensors are likely to remain in high demand in medical device markets. For the current study, we developed a needle-type bio-layer interference (BLI) sensor that can continuously monitor glucose levels. Using dialysis procedures, we were able to obtain hypoglycemic samples from commercial human serum. These dialysis-derived samples, alongside samples of normal human serum were used to evaluate the utility of the sensor for the detection of the clinical interest range of glucose concentrations (70-200 mg/dL), revealing high system performance for a wide glycemic state range (45-500 mg/dL). Reversibility and reproducibility were also tested over a range of time spans. Combined with existing BLI system technology, this sensor holds great promise for use as a wearable online continuous glucose monitoring system for patients in a hospital setting.

Nanotechnology in glucose monitoring: advances and challenges in the last 10 years.

PubMed

Scognamiglio, Viviana

2013-09-15

In the last decades, a wide multitude of research activity has been focused on the development of biosensors for glucose monitoring, devoted to overcome the challenges associated with smart analytical performances with commercial implications. Crucial issues still nowadays elude biosensors to enter the market, such as sensitivity, stability, miniaturisation, continuous and in situ monitoring in a complex matrix. A noteworthy tendency of biosensor technology is likely to push towards nanotechnology, which allows to reduce dimensions at the nanoscale, consenting the construction of arrays for high throughput analysis with the integration of microfluidics, and enhancing the performance of the biological components by using new nanomaterials. This review aims to highlight current trends in biosensors for glucose monitoring based on nanotechnology, reporting widespread representative examples of the recent approaches for nanobiosensors over the past 10 years. Progress in nanotechnology for the development of biosensing systems for blood glucose level monitoring will be discussed, in view of their design and construction on the bases of the new materials offered by nanotechnology. Copyright © 2013 Elsevier B.V. All rights reserved.

A case of perioperative glucose control by using an artificial pancreas in a patient with glycogen storage disease.

PubMed

Yatabe, Tomoaki; Nakamura, Ryu; Kitagawa, Hiroyuki; Munekage, Masaya; Hanazaki, Kazuhiro

2016-03-01

A 57-year-old woman was diagnosed with type I glycogen storage disease in her twenties. She had undergone hepatectomy under general anesthesia with epidural anesthesia. Fifty minutes after the induction of anesthesia, a 20-gauge venous catheter was inserted in the patient's right hand, and an artificial pancreas (STG-55, Nikkiso Co., Tokyo, Japan) was connected for continuous glucose monitoring and automatic glucose control. Insulin was infused when the blood glucose level reached 120 mg/dL or higher, and glucose was infused when the level fell to 100 mg/dL or lower. After the Pringle maneuver, the blood glucose level increased, and insulin was administered automatically via an artificial pancreas. Hypoglycemia did not occur during the operation. After total parenteral nutrition was started in the intensive care unit (ICU), the blood glucose level increased, and the artificial pancreas controlled the blood glucose level through automatic insulin administration. Thirty-four hours after admission to the ICU, the artificial pancreas was removed because the blood sampling failed. After the removal of the artificial pancreas, blood glucose level was measured every 2 h until extubation. During the ICU stay, hypoglycemia never occurred, with the average blood glucose level being 144 mg/dL. In conclusion, the use of an artificial pancreas for perioperative blood glucose management in a patient with glycogen storage disease had the beneficial effect of enabling the management of blood glucose levels without hypoglycemia.

[Gestational diabetes mellitus].

PubMed

Kautzky-Willer, Alexandra; Harreiter, Jürgen; Bancher-Todesca, Dagmar; Berger, Angelika; Repa, Andreas; Lechleitner, Monika; Weitgasser, Raimund

2016-04-01

Gestational diabetes (GDM) is defined as any degree of glucose intolerance with onset during pregnancy and is associated with increased feto-maternal morbidity as well as long-term complications in mothers and offspring. Women detected to have diabetes early in pregnancy receive the diagnosis of overt, non-gestational, diabetes (glucose: fasting > 126 mg/dl, spontaneous > 200 mg/dl or HbA1c > 6.5 % before 20 weeks of gestation). GDM is diagnosed by an oral glucose tolerance test (OGTT) or fasting glucose concentrations (> 92 mg/dl). Screening for undiagnosed type 2 diabetes at the first prenatal visit (Evidence level B) is recommended in women at increased risk using standard diagnostic criteria (high risk: history of GDM or pre-diabetes (impaired fasting glucose or impaired glucose tolerance); malformation, stillbirth, successive abortions or birth weight > 4,500 g in previous pregnancies; obesity, metabolic syndrome, age > 45 years, vascular disease; clinical symptoms of diabetes (e. g. glucosuria)). Performance of the OGTT (120 min; 75 g glucose) may already be indicated in the first trimester in some women but is mandatory between 24 and 28 gestational weeks in all pregnant women with previous non-pathological glucose metabolism (Evidence level B). Based on the results of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study GDM is defined, if fasting venous plasma glucose exceeds 92 mg/dl or 1 h 180 mg/dl or 2 h 153 mg/dl after glucose loading (OGTT; international consensus criteria). In case of one pathological value a strict metabolic control is mandatory. This diagnostic approach was recently also recommended by the WHO. All women should receive nutritional counseling and be instructed in blood glucose self-monitoring and to increase physical activity to moderate intensity levels- if not contraindicated. If blood glucose levels cannot be maintained in the normal range (fasting < 95 mg/dl and 1 h after meals < 140 mg/dl) insulin therapy should be initiated as first choice. Maternal and fetal monitoring is required in order to minimize maternal and fetal/neonatal morbidity and perinatal mortality. After delivery all women with GDM have to be reevaluated as to their glucose tolerance by a 75 g OGTT (WHO criteria) 6-12 weeks postpartum and every 2 years in case of normal glucose tolerance (Evidence level B). All women have to be instructed about their (sevenfold increased relative) risk of type 2 diabetes at follow-up and possibilities for diabetes prevention, in particular weight management and maintenance/increase of physical activity. Monitoring of the development of the offspring and recommendation of healthy lifestyle of the children and family is recommended.

Comparison of vildagliptin twice daily vs. sitagliptin once daily using continuous glucose monitoring (CGM): Crossover pilot study (J-VICTORIA study)

PubMed Central

2012-01-01

Background No previous studies have compared the DPP-4 inhibitors vildagliptin and sitagliptin in terms of blood glucose levels using continuous glucose monitoring (CGM) and cardiovascular parameters. Methods Twenty patients with type 2 diabetes mellitus were randomly allocated to groups who received vildagliptin then sitagliptin, or vice versa. Patients were hospitalized at 1 month after starting each drug, and CGM was used to determine: 1) mean (± standard deviation) 24-hour blood glucose level, 2) mean amplitude of glycemic excursions (MAGE), 3) fasting blood glucose level, 4) highest postprandial blood glucose level and time, 5) increase in blood glucose level after each meal, 6) area under the curve (AUC) for blood glucose level ≥180 mg/dL within 3 hours after each meal, and 7) area over the curve (AOC) for daily blood glucose level <70 mg/dL. Plasma glycosylated hemoglobin (HbA1c), glycoalbumin (GA), 1,5-anhydroglucitol (1,5AG), immunoreactive insulin (IRI), C-peptide immunoreactivity (CPR), brain natriuretic peptide (BNP), and plasminogen activator inhibitor-1 (PAI-1) levels, and urinary CPR levels, were measured. Results The mean 24-hour blood glucose level was significantly lower in patients taking vildagliptin than sitagliptin (142.1 ± 35.5 vs. 153.2 ± 37.0 mg/dL; p = 0.012). In patients taking vildagliptin, MAGE was significantly lower (110.5 ± 33.5 vs. 129.4 ± 45.1 mg/dL; p = 0.040), the highest blood glucose level after supper was significantly lower (206.1 ± 40.2 vs. 223.2 ± 43.5 mg/dL; p = 0.015), the AUC (≥180 mg/dL) within 3 h was significantly lower after breakfast (484.3 vs. 897.9 mg/min/dL; p = 0.025), and urinary CPR level was significantly higher (97.0 ± 41.6 vs. 85.2 ± 39.9 μg/day; p = 0.008) than in patients taking sitagliptin. There were no significant differences in plasma HbA1c, GA, 1,5AG, IRI, CPR, BNP, or PAI-1 levels between patients taking vildagliptin and sitagliptin. Conclusions CGM showed that mean 24-h blood glucose, MAGE, highest blood glucose level after supper, and hyperglycemia after breakfast were significantly lower in patients with type 2 diabetes mellitus taking vildagliptin than those taking sitagliptin. There were no significant differences in BNP and PAI-1 levels between patients taking vildagliptin and sitagliptin. Trial registration UMIN000007687 PMID:22867630

Fabrication of interdigitated high-performance zinc oxide nanowire modified electrodes for glucose sensing.

PubMed

Haarindraprasad, R; Hashim, Uda; Gopinath, Subash C B; Perumal, Veeradasan; Liu, Wei-Wen; Balakrishnan, S R

2016-06-21

Diabetes is a metabolic disease with a prolonged elevated level of glucose in the blood leads to long-term complications and increases the chances for cardiovascular diseases. The present study describes the fabrication of a ZnO nanowire (NW)-modified interdigitated electrode (IDE) to monitor the level of blood glucose. A silver IDE was generated by wet etching-assisted conventional lithography, with a gap between adjacent electrodes of 98.80 μm. The ZnO-based thin films and NWs were amended by sol-gel and hydrothermal routes. High-quality crystalline and c-axis orientated ZnO thin films were observed by XRD analyses. The ZnO thin film was annealed for 1, 3 and 5 h, yielding a good-quality crystallite with sizes of 50, 100 and 110 nm, and the band gaps were measured as 3.26, 3.20 and 3.17 eV, respectively. Furthermore, a flower-modeled NW was obtained with the lowest diameter of 21 nm. Our designed ZnO NW-modified IDE was shown to have a detection limit as low as 0.03 mg/dL (correlation coefficient = 0.98952) of glucose with a low response time of 3 s, perform better than commercial glucose meter, suitable to instantly monitor the glucose level of diabetes patients. This study demonstrated the high performance of NW-mediated IDEs for glucose sensing as alternative to current glucose sensors. Copyright © 2016 Elsevier B.V. All rights reserved.

Mid-Infrared Photoacoustic Detection of Glucose in Human Skin: Towards Non-Invasive Diagnostics

PubMed Central

Kottmann, Jonas; Rey, Julien M.; Sigrist, Markus W.

2016-01-01

Diabetes mellitus is a widespread metabolic disease without cure. Great efforts are being made to develop a non-invasive monitoring of the blood glucose level. Various attempts have been made, including a number of non-optical approaches as well as optical techniques involving visible, near- and mid-infrared light. However, no true breakthrough has been achieved so far, i.e., there is no fully non-invasive monitoring device available. Here we present a new study based on mid-infrared spectroscopy and photoacoustic detection. We employ two setups, one with a fiber-coupled photoacoustic (PA) cell and a tunable quantum cascade laser (QCL), and a second setup with two QCLs at different wavelengths combined with PA detection. In both cases, the PA cells are in direct skin contact. The performance is tested with an oral glucose tolerance test. While the first setup often gives reasonable qualitative agreement with ordinary invasive blood glucose measurements, the dual-wavelength approach yields a considerably improved stability and an uncertainty of only ±30 mg/dL of the blood glucose concentration level at a confidence level of 90%. This result is achieved without advanced data treatment such as principal component analysis involving extended wavelength ranges. PMID:27735878

Value of self-monitoring blood glucose pattern analysis in improving diabetes outcomes.

PubMed

Parkin, Christopher G; Davidson, Jaime A

2009-05-01

Self-monitoring of blood glucose (SMBG) is an important adjunct to hemoglobin A1c (HbA1c) testing. This action can distinguish between fasting, preprandial, and postprandial hyperglycemia; detect glycemic excursions; identify and monitor resolution of hypoglycemia; and provide immediate feedback to patients about the effect of food choices, activity, and medication on glycemic control. Pattern analysis is a systematic approach to identifying glycemic patterns within SMBG data and then taking appropriate action based upon those results. The use of pattern analysis involves: (1) establishing pre- and postprandial glucose targets; (2) obtaining data on glucose levels, carbohydrate intake, medication administration (type, dosages, timing), activity levels and physical/emotional stress; (3) analyzing data to identify patterns of glycemic excursions, assessing any influential factors, and implementing appropriate action(s); and (4) performing ongoing SMBG to assess the impact of any therapeutic changes made. Computer-based and paper-based data collection and management tools can be developed to perform pattern analysis for identifying patterns in SMBG data. This approach to interpreting SMBG data facilitates rational therapeutic adjustments in response to this information. Pattern analysis of SMBG data can be of equal or greater value than measurement of HbA1c levels. 2009 Diabetes Technology Society.

Tale of two sites: capillary versus arterial blood glucose testing in the operating room.

PubMed

Akinbami, Felix; Segal, Scott; Schnipper, Jeffrey L; Stopfkuchen-Evans, Matthias; Mills, Jonathan; Rogers, Selwyn O

2012-04-01

Pre- and intraoperative glycemic control has been identified as a putative target to improve outcomes of surgical patients. Glycemic control requires frequent monitoring of blood glucose levels with appropriate adjustments. However, monitoring standards have been called into question, especially in cases in which capillary samples are used. Point-of-care testing (POCT) using capillary samples and glucometers has been noted to give relatively accurate results for critically ill patients. However, the package inserts of most glucometers warn that they should not be used for patients in shock. This has led clinicians to doubt their accuracy in the operating room. The accuracy of capillary samples when tested in patients undergoing surgical procedures has not been proven. This study aims to determine the accuracy of intraoperative blood glucose values using capillary samples relative to arterial samples. A prospective study was conducted by collecting paired capillary and arterial samples of patients undergoing major operations at a tertiary medical center from August 2009 to May 2011. Subjects were a convenience sample of patients who had arterial lines and needed glucose testing while undergoing the procedure. Precision Xceed Pro (Abbott) handheld glucometers were used to obtain the blood glucose values. Our primary outcome of interest was the degree of correlation between capillary and arterial blood glucose values or the degree to which arterial glucose levels can be predicted by capillary glucose samples. We used linear regression and the Student t tests for statistical analyses. Seventy-two-paired samples were collected. Of the cases, 54% were major abdominal operations, whereas 24% were vascular operations. The mean values ± standard deviation for glucose levels were 146 ± 35 mg/dL (capillary) and 147 ± 36 mg/dL (arterial). The mean time ± standard deviation between the collection of both samples was 3.5 ± 1.3 minutes. The regression coefficient showed a strong positive correlation of .91 between capillary glucose values and arterial values (P < .001) although correlation was less stringent at the hyperglycemic range of values. The R(2) statistic was 84%. Differences in values between capillary and arterial samples would not have altered the diagnosis of hypo- and hyperglycemia using typical thresholds. Capillary samples collected intraoperatively are strongly correlated with arterial samples. Glucose monitoring in the operating room can be safely performed by collecting capillary samples for POCT. However, clinicians should still be cautious when interpreting glucose levels that are high, either by repeating the blood glucose test or by having samples sent to the laboratory. Copyright © 2012 Elsevier Inc. All rights reserved.

An artificial pancreas provided a novel model of blood glucose level variability in beagles.

PubMed

Munekage, Masaya; Yatabe, Tomoaki; Kitagawa, Hiroyuki; Takezaki, Yuka; Tamura, Takahiko; Namikawa, Tsutomu; Hanazaki, Kazuhiro

2015-12-01

Although the effects on prognosis of blood glucose level variability have gained increasing attention, it is unclear whether blood glucose level variability itself or the manifestation of pathological conditions that worsen prognosis. Then, previous reports have not been published on variability models of perioperative blood glucose levels. The aim of this study is to establish a novel variability model of blood glucose concentration using an artificial pancreas. We maintained six healthy, male beagles. After anesthesia induction, a 20-G venous catheter was inserted in the right femoral vein and an artificial pancreas (STG-22, Nikkiso Co. Ltd., Tokyo, Japan) was connected for continuous blood glucose monitoring and glucose management. After achieving muscle relaxation, total pancreatectomy was performed. After 1 h of stabilization, automatic blood glucose control was initiated using the artificial pancreas. Blood glucose level varied for 8 h, alternating between the target blood glucose values of 170 and 70 mg/dL. Eight hours later, the experiment was concluded. Total pancreatectomy was performed for 62 ± 13 min. Blood glucose swings were achieved 9.8 ± 2.3 times. The average blood glucose level was 128.1 ± 5.1 mg/dL with an SD of 44.6 ± 3.9 mg/dL. The potassium levels after stabilization and at the end of the experiment were 3.5 ± 0.3 and 3.1 ± 0.5 mmol/L, respectively. In conclusion, the results of the present study demonstrated that an artificial pancreas contributed to the establishment of a novel variability model of blood glucose levels in beagles.

Optical coherence tomography for blood glucose monitoring in vitro through spatial and temporal approaches

NASA Astrophysics Data System (ADS)

De Pretto, Lucas Ramos; Yoshimura, Tania Mateus; Ribeiro, Martha Simões; Zanardi de Freitas, Anderson

2016-08-01

As diabetes causes millions of deaths worldwide every year, new methods for blood glucose monitoring are in demand. Noninvasive approaches may increase patient adherence to treatment while reducing costs, and optical coherence tomography (OCT) may be a feasible alternative to current invasive diagnostics. This study presents two methods for blood sugar monitoring with OCT in vitro. The first, based on spatial statistics, exploits changes in the light total attenuation coefficient caused by different concentrations of glucose in the sample using a 930-nm commercial OCT system. The second, based on temporal analysis, calculates differences in the decorrelation time of the speckle pattern in the OCT signal due to blood viscosity variations with the addition of glucose with data acquired by a custom built Swept Source 1325-nm OCT system. Samples consisted of heparinized mouse blood, phosphate buffer saline, and glucose. Additionally, further samples were prepared by diluting mouse blood with isotonic saline solution to verify the effect of higher multiple scattering components on the ability of the methods to differentiate glucose levels. Our results suggest a direct relationship between glucose concentration and both decorrelation rate and attenuation coefficient, with our systems being able to detect changes of 65 mg/dL in glucose concentration.

Effects of simulated altitude on blood glucose meter performance: implications for in-flight blood glucose monitoring.

PubMed

Olateju, Tolu; Begley, Joseph; Flanagan, Daniel; Kerr, David

2012-07-01

Most manufacturers of blood glucose monitoring equipment do not give advice regarding the use of their meters and strips onboard aircraft, and some airlines have blood glucose testing equipment in the aircraft cabin medical bag. Previous studies using older blood glucose meters (BGMs) have shown conflicting results on the performance of both glucose oxidase (GOX)- and glucose dehydrogenase (GDH)-based meters at high altitude. The aim of our study was to evaluate the performance of four new-generation BGMs at sea level and at a simulated altitude equivalent to that used in the cabin of commercial aircrafts. Blood glucose measurements obtained by two GDH and two GOX BGMs at sea level and simulated altitude of 8000 feet in a hypobaric chamber were compared with measurements obtained using a YSI 2300 blood glucose analyzer as a reference method. Spiked venous blood samples of three different glucose levels were used. The accuracy of each meter was determined by calculating percentage error of each meter compared with the YSI reference and was also assessed against standard International Organization for Standardization (ISO) criteria. Clinical accuracy was evaluated using the consensus error grid method. The percentage (standard deviation) error for GDH meters at sea level and altitude was 13.36% (8.83%; for meter 1) and 12.97% (8.03%; for meter 2) with p = .784, and for GOX meters was 5.88% (7.35%; for meter 3) and 7.38% (6.20%; for meter 4) with p = .187. There was variation in the number of time individual meters met the standard ISO criteria ranging from 72-100%. Results from all four meters at both sea level and simulated altitude fell within zones A and B of the consensus error grid, using YSI as the reference. Overall, at simulated altitude, no differences were observed between the performance of GDH and GOX meters. Overestimation of blood glucose concentration was seen among individual meters evaluated, but none of the results obtained would have resulted in dangerous failure to detect and treat blood glucose errors or in giving treatment that was actually contradictory to that required. © 2012 Diabetes Technology Society.

The relationship between maternal fear of hypoglycaemia and adherence in children with type-1 diabetes.

PubMed

Freckleton, Evril; Sharpe, Louise; Mullan, Barbara

2014-01-01

Regular blood glucose monitoring is important for children with type-1 diabetes; however, the relationship between maternal fear of hypoglycaemia and glycaemic control is not well understood. The relationship between maternal beliefs about diabetes, concerns about glycaemic control and adherence to recommended blood glucose levels in young children with type-1 diabetes were examined in this study. Seventy-one mothers with children under 13 were recruited, and a prospective design was used. Demographics, maternal self-reported hypoglycaemic fear and illness perceptions were measured at baseline. Self-report daily blood sugar levels were recorded over 1 week, and glycosylated haemoglobin (HbA1c) blood glucose levels were collected at baseline and 3 months later. High maternal fears of hypoglycaemia were predictive of suboptimal daily glycaemic control (elevated blood glucose levels), irrespective of illness duration or age at diagnosis. The results suggest that mothers who worry most about hypoglycaemia compensate by maintaining their child's blood glucose levels above recommended levels. Elevated blood glucose levels have important consequences for long-term health, and further research could explore ways to target maternal fear of hypoglycaemia.

Method and apparatus for non-invasive monitoring of blood glucose

DOEpatents

Thomas, Graham H.; Watson, Roger M.; Noell, J. Oakey

1992-06-09

A new and improved method and apparatus are provided for non-invasive monitoring of changes in blood glucose concentration in a tissue specimen and particularly in an individual. The method uses acoustic velocity measurements for monitoring the effect of glucose concentration upon the density and adiabatic compressibility of the serum. In a preferred embodiment, the acoustic velocity measurements are made through the earlobe of a subject by means of an acoustic probe or monitor which includes a transducer for transmitting and receiving ultrasonic energy pulses to and from the blood flowing in the subject's earlobe and a reflector for facilitating reflection of the acoustic pulses from the blood. The probe is designed in such a way that when properly affixed to an ear, the transducer is positioned flush against the anterior portion of an earlobe while the reflector is positioned flush against the interior portion of the earlobe. A microthermocouple is provided on the probe for monitoring the internal temperature of the blood being sampled. An electrical system, essentially comprising a frequency generator, a time intervalometer and an oscilloscope, is linked to the glucose monitoring probe. The electrical system analyzes selected ones of the pulses reflected from the blood sample in order to determine therefrom the acoustic velocity of the blood which, in turn, provides a representation of the blood glucose concentration levels at the time of the acoustic velocity measurements.

Assessing performance of closed-loop insulin delivery systems by continuous glucose monitoring: drawbacks and way forward.

PubMed

Hovorka, Roman; Nodale, Marianna; Haidar, Ahmad; Wilinska, Malgorzata E

2013-01-01

We investigated whether continuous glucose monitoring (CGM) levels can accurately assess glycemic control while directing closed-loop insulin delivery. Data were analyzed retrospectively from 33 subjects with type 1 diabetes who underwent closed-loop and conventional pump therapy on two separate nights. Glycemic control was evaluated by reference plasma glucose and contrasted against three methods based on Navigator (Abbott Diabetes Care, Alameda, CA) CGM levels. Glucose mean and variability were estimated by unmodified CGM levels with acceptable clinical accuracy. Time when glucose was in target range was overestimated by CGM during closed-loop nights (CGM vs. plasma glucose median [interquartile range], 86% [65-97%] vs. 75% [59-91%]; P=0.04) but not during conventional pump therapy (57% [32-72%] vs. 51% [29-68%]; P=0.82) providing comparable treatment effect (mean [SD], 28% [29%] vs. 23% [21%]; P=0.11). Using the CGM measurement error of 15% derived from plasma glucose-CGM pairs (n=4,254), stochastic interpretation of CGM gave unbiased estimate of time in target during both closed-loop (79% [62-86%] vs. 75% [59-91%]; P=0.24) and conventional pump therapy (54% [33-66%] vs. 51% [29-68%]; P=0.44). Treatment effect (23% [24%] vs. 23% [21%]; P=0.96) and time below target were accurately estimated by stochastic CGM. Recalibrating CGM using reference plasma glucose values taken at the start and end of overnight closed-loop was not superior to stochastic CGM. CGM is acceptable to estimate glucose mean and variability, but without adjustment it may overestimate benefit of closed-loop. Stochastic CGM provided unbiased estimate of time when glucose is in target and below target and may be acceptable for assessment of closed-loop in the outpatient setting.

Noninvasive Ultrasound Transdermal Insulin Delivery and Glucose Monitoring Using a Low-Profile Cymbal Array

NASA Astrophysics Data System (ADS)

Park, E.-J.; Luis, J.; Meyer, R. J.; Pishko, M. V.; Smith, N. B.

2006-05-01

Recent studies have shown that ultrasound mediated transdermal drug delivery offers promising results for noninvasive drug administration. The purpose of this study was to demonstrate ultrasonic transdermal insulin delivery and in vivo sensing glucose with a novel, low-profile ultrasound array based on the cymbal transducer. As a practical device, the array composed of circular cymbal transducers was thin (< 7mm) and weighed less than 22g. Using this array on hyperglycemic rats, our previous experiments demonstrated that blood glucose would decrease by 296.7 mg/dL from 60 minutes of ultrasound exposure. With a similar intensity, our goal was to evaluate the feasibility of insulin delivery with large animals (rabbits and pigs) and noninvasively determine the glucose level of hyperglycemic rats with the array system. Ultrasound was exposed for 60 minutes at Isptp=100 mW/cm2. With the same procedure, a preliminary experiment of large animal was performed on a pig (12 kg) at Isptp=50 mW/cm2. For the control experiments in insulin delivery, the blood glucose level varied little from the initial baseline. However, for the ultrasound and insulin exposure experiment, the glucose level was found to decrease by 132.6 mg/dL in 60 minutes and continued to decrease by 208.1 mg/dL in 90 minutes. From the preliminary pig experiment, the blood glucose level decreased by 120 mg/dL in 90 minutes. To noninvasively determine the glucose level, ultrasound exposure experiments with an electrochemical glucose biosensor were performed on hyperglycemic rats. After 20 minutes ultrasound exposure, the biosensor was placed at the exposure area to determine the concentration of glucose diffused through the skin. The glucose level of rats determined by the biosensor was 408 mg/dL which was very similar to the results of conventional glucose meter reading 396.7 mg/dL. Recently, a rectangular cymbal transducer was developed to obtain a larger sonication area without an increase in array size. Preliminary experiments were performed on hyperglycemic rabbits to evaluate the new transducer design. The results showed that the rectangular array has enhanced performance compared to the circular array. All results of ultrasound application indicate the feasibility of using a low-cost, light-weight cymbal array for enhanced noninvasive transdermal insulin delivery and glucose monitoring.

Blood Glucose Levels Following Intra-Articular Steroid Injections in Patients with Diabetes: A Systematic Review.

PubMed

Choudhry, M N; Malik, R A; Charalambous, Charalambos Panayiotou

2016-03-22

Parenterally administered steroids have been shown to affect the metabolism of glucose and to cause abnormal blood glucose levels in diabetic patients. These abnormal blood glucose levels in diabetic patients raise concerns that intra-articular steroid injections also may affect blood glucose levels. We performed a systematic review of studies examining the effect of intra-articular steroid injections on blood glucose levels in patients with diabetes mellitus. A literature search of the PubMed, EMBASE, AMED, and CINAHL databases using all relevant keywords and phrases revealed 532 manuscripts. After the application of inclusion criteria, seven studies with a total of seventy-two patients were analyzed. All studies showed a rise in blood glucose levels following intra-articular steroid injection. Four of the seven studies showed a substantial increase in blood glucose. Peak values reached as high as 500 mg/dL. The peak increase in blood glucose did not occur immediately following intra-articular steroid injection, and in some cases it took several days to occur. In many patients, post-injection hyperglycemia occurred within twenty-four to seventy-two hours. Intra-articular steroid injections may cause hyperglycemia in patients with diabetes mellitus, and patients should be warned of this complication. Diabetic patients should be advised to regularly monitor their blood glucose levels for up to a week after injection and should seek medical advice if safe thresholds are breached. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Single Cell "Glucose Nanosensor" Verifies Elevated Glucose Levels in Individual Cancer Cells.

PubMed

Nascimento, Raphael A S; Özel, Rıfat Emrah; Mak, Wai Han; Mulato, Marcelo; Singaram, Bakthan; Pourmand, Nader

2016-02-10

Because the transition from oxidative phosphorylation to anaerobic glycolytic metabolism is a hallmark of cancer progression, approaches to identify single living cancer cells by their unique glucose metabolic signature would be useful. Here, we present nanopipettes specifically developed to measure glucose levels in single cells with temporal and spatial resolution, and we use this technology to verify the hypothesis that individual cancer cells can indeed display higher intracellular glucose levels. The nanopipettes were functionalized as glucose nanosensors by immobilizing glucose oxidase (GOx) covalently to the tip so that the interaction of glucose with GOx resulted in a catalytic oxidation of β-d-glucose to d-gluconic acid, which was measured as a change in impedance due to drop in pH of the medium at the nanopipette tip. Calibration studies showed a direct relationship between impedance changes at the tip and glucose concentration in solution. The glucose nanosensor quantified single cell intracellular glucose levels in human fibroblasts and the metastatic breast cancer lines MDA-MB-231 and MCF7 and revealed that the cancer cells expressed reproducible and reliable increases in glucose levels compared to the nonmalignant cells. Nanopipettes allow repeated sampling of the same cell, as cells remain viable during and after measurements. Therefore, nanopipette-based glucose sensors provide an approach to compare changes in glucose levels with changes in proliferative or metastatic state. The platform has great promise for mechanistic investigations, as a diagnostic tool to distinguish cancer cells from nonmalignant cells in heterogeneous tissue biopsies, as well as a tool for monitoring cancer progression in situ.

Hyperglycemia and subsequent torsades de pointes with marked QT prolongation during refeeding.

PubMed

Nakashima, Takashi; Kubota, Tomoki; Takasugi, Nobuhiro; Kitagawa, Yuichiro; Yoshida, Takahiro; Ushikoshi, Hiroaki; Kawasaki, Masanori; Nishigaki, Kazuhiko; Ogura, Shinji; Minatoguchi, Shinya

2017-01-01

A fatal cardiac complication can occasionally present in malnourished patients during refeeding; this is known as refeeding syndrome. However, to our knowledge, hyperglycemia preceding torsades de pointes with QT prolongation during refeeding has not been reported. In the present study, we present a case in which hyperglycemia preceded torsades de pointes with QT prolongation during refeeding. The aim of this study was to determine the possible mechanism underlying QT prolongation during refeeding and indicate how to prevent it. A 32-y-old severely malnourished woman (body mass index 14.57 kg/m 2 ) was admitted to the intensive care unit of our institution after resuscitation from cardiopulmonary arrest due to ventricular fibrillation. She was diagnosed with anorexia nervosa. Although no obvious electrolyte abnormalities were observed, her blood glucose level was 11 mg/dL. A 12-lead electrocardiogram at admission showed sinus rhythm with normal QT interval (QTc 0.448). Forty mL of 50% glucose (containing 20 g of glucose) was intravenously injected, followed by a drip infusion of glucose to maintain blood glucose level within normal range. After 9 h, the patient's blood glucose level increased to 569 mg/dL. However, after 38 h, an episode of marked QT prolongation (QTc 0.931) followed by torsades de pointes developed. Hyperglycemia during refeeding can present with QT prolongation; consequently, monitoring blood glucose levels may be useful in avoiding hyperglycemia, which can result in QT prolongation. Furthermore, additional monitoring of QT intervals using a 12-lead electrocardiogram should allow the early detection of QT prolongation when glucose solution is administered to a malnourished patient with (severe) hypoglycemia. Copyright © 2016 Elsevier Inc. All rights reserved.

Numerical and clinical precision of continuous glucose monitoring in Colombian patients treated with insulin infusion pump with automated suspension in hypoglycemia.

PubMed

Gómez, Ana M; Marín Sánchez, Alejandro; Muñoz, Oscar M; Colón Peña, Christian Alejandro

2015-12-01

Insulin pump therapy associated with continuous glucose monitoring has shown a positive clinical impact on diabetes control and reduction of hypoglycemia episodes. There are descriptions of the performance of this device in other populations, but its precision and accuracy in Colombia and Latin America are unknown, especially in the routine outpatient setting. Data from 33 type 1 and type 2 diabetes patients with sensor-augmented pump therapy with threshold suspend automation, MiniMed Paradigm® Veo™ (Medtronic, Northridge, California), managed at Hospital Universitario San Ignacio (Bogotá, Colombia) and receiving outpatient treatment, were analyzed. Simultaneous data from continuous glucose monitoring and capillary blood glucose were compared, and their precision and accuracy were calculating with different methods, including Clarke error grid. Analyses included 2,262 continuous glucose monitoring -reference paired glucose values. A mean absolute relative difference of 20.1% was found for all measurements, with a value higher than 23% for glucose levels ≤75mg/dL. Global compliance with the ISO criteria was 64.9%. It was higher for values >75mg/dl (68.3%, 1,308 of 1,916 readings), than for those ≤ 75mg/dl (49.4%, 171 of 346 readings). Clinical accuracy, as assessed by the Clarke error grid, showed that 91.77% of data were within the A and B zones (75.6% in hypoglycemia). A good numerical accuracy was found for continuous glucose monitoring in normo and hyperglycemia situations, with low precision in hypoglycemia. The clinical accuracy of the device was adequate, with no significant safety concerns for patients. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Seven-Year Clinical Surveillance Program Demonstrates Consistent MARD Accuracy Performance of a Blood Glucose Test Strip.

PubMed

Setford, Steven; Grady, Mike; Mackintosh, Stephen; Donald, Robert; Levy, Brian

2018-05-01

MARD (mean absolute relative difference) is increasingly used to describe performance of glucose monitoring systems, providing a single-value quantitative measure of accuracy and allowing comparisons between different monitoring systems. This study reports MARDs for the OneTouch Verio® glucose meter clinical data set of 80 258 data points (671 individual batches) gathered as part of a 7.5-year self-surveillance program Methods: Test strips were routinely sampled from randomly selected manufacturer's production batches and sent to one of 3 clinic sites for clinical accuracy assessment using fresh capillary blood from patients with diabetes, using both the meter system and standard laboratory reference instrument. Evaluation of the distribution of strip batch MARD yielded a mean value of 5.05% (range: 3.68-6.43% at ±1.96 standard deviations from mean). The overall MARD for all clinic data points (N = 80 258) was also 5.05%, while a mean bias of 1.28 was recorded. MARD by glucose level was found to be consistent, yielding a maximum value of 4.81% at higher glucose (≥100 mg/dL) and a mean absolute difference (MAD) of 5.60 mg/dL at low glucose (<100 mg/dL). MARD by year of manufacture varied from 4.67-5.42% indicating consistent accuracy performance over the surveillance period. This 7.5-year surveillance program showed that this meter system exhibits consistently low MARD by batch, glucose level and year, indicating close agreement with established reference methods whilste exhibiting lower MARD values than continuous glucose monitoring (CGM) systems and providing users with confidence in the performance when transitioning to each new strip batch.

Evaluation of postprandial glucose excursion using a novel minimally invasive glucose area-under-the-curve monitoring system.

PubMed

Kuranuki, Sachi; Sato, Toshiyuki; Okada, Seiki; Hosoya, Samiko; Seko, Akinobu; Sugihara, Kaya; Nakamura, Teiji

2013-01-01

To develop a minimally invasive interstitial fluid extraction technology (MIET) to monitor postprandial glucose area under the curve (AUC) without blood sampling, we evaluated the accuracy of glucose AUC measured by MIET and compared with that by blood sampling after food intake. Interstitial fluid glucose AUC (IG-AUC) following consumption of 6 different types of foods was measured by MIET. MIET consisted of stamping microneedle arrays, placing hydrogel patches on the areas, and calculating IG-AUC based on glucose levels in the hydrogels. Glycemic index (GI) was determined using IG-AUC and reference AUC measured by blood sampling. IG-AUC strongly correlated with reference AUC (R = 0.91), and GI determined using IG-AUC showed good correlation with that determined by reference AUC (R = 0.88). IG-AUC obtained by MIET can accurately predict the postprandial glucose excursion without blood sampling. In addition, feasibility of GI measurement by MIET was confirmed.

Proton mediated control of biochemical reactions with bioelectronic pH modulation

NASA Astrophysics Data System (ADS)

Deng, Yingxin; Miyake, Takeo; Keene, Scott; Josberger, Erik E.; Rolandi, Marco

2016-04-01

In Nature, protons (H+) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H+ channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H+ currents and H+ concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H+ between PdHx contacts and solution. The present transducer records bistable pH modulation from an “enzymatic flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. The transducer also controls bioluminescence from firefly luciferase by affecting solution pH.

Hybrid CARS for Non-Invasive Blood Glucose Monitoring

NASA Astrophysics Data System (ADS)

Wang, Xi; Pestov, Dmitry; Zhang, Aihua; Murawski, Robert; Sokolov, Alexei; Welch, George; Laane, Jaan; Scully, Marlan

2007-10-01

We develop a spectroscopy technique that combines the advantages of both the frequency-resolved coherent anti-Stokes Raman scattering (CARS) and the time-resolved CARS. We use broadband preparation pulses to get an instantaneous coherent excitation of multiplex molecular vibration levels and subsequent optically shaped time-delayed narrowband probing pulse to detect these vibrations. This technique can suppress the nonresonant background and retrieve the molecular fingerprint signal efficiently and rapidly. We employ this technique to glucose detection, the final goal of which is accurate, non-invasive (i.e. painless) and continuous monitoring of blood glucose concentration in the Diabetes diagnosis to replace the current glucose measurement process, which requires painful fingerpricks and therefore cannot be performed more than a few times a day. We have gotten the CARS spectra of glucose aqueous solution down to 2 mM.

Diurnal glycemic profile in obese and normal weight nondiabetic pregnant women.

PubMed

Yogev, Yariv; Ben-Haroush, Avi; Chen, Rony; Rosenn, Barak; Hod, Moshe; Langer, Oded

2004-09-01

A paucity of data exists concerning the normal glycemic profile in nondiabetic pregnancies. Using a novel approach that provides continuous measurement of blood glucose, we sought to evaluate the ambulatory daily glycemic profile in the second half of pregnancy in nondiabetic women. Fifty-seven obese and normal weight nondiabetic subjects were evaluated for 72 consecutive hours with continuous glucose monitoring by measurement interstitial glucose levels in subcutaneous tissue every 5 minutes. Subjects were instructed not to modify their lifestyle or to follow any dietary restriction. For each woman, mean and fasting blood glucose values were determined; for each meal during the study period, the first 180 minutes were analyzed. For the study group, the fasting blood glucose level was 75 +/- 12 mg/dL; the mean blood glucose level was 83.7 +/- 18 mg/dL; the postprandial peak glucose value level was 110 +/- 16 mg/dL, and the time interval that was needed to reach peak postprandial glucose level was 70 +/- 13 minutes. A similar postprandial glycemic profile was obtained for breakfast, lunch, and dinner. Obese women were characterized by a significantly higher postprandial glucose peak value, increased 1- and 2-hour postprandial glucose levels, increased time interval for glucose peak, and significantly lower mean blood glucose during the night. No difference was found in fasting and mean blood glucose between obese and nonobese subjects. Glycemic profile characterization in both obese and normal weight nondiabetic subjects provide a measure for the desired level of glycemic control in pregnancy that is complicated with diabetes mellitus.

Non-invasive biosensor and wilreless interrogating system for hypoglycemia

NASA Astrophysics Data System (ADS)

Varadan, Vijay K.; Whitchurch, Ashwin K.; Saukesi, K.

2002-11-01

Hypoglycemia - abnormal decrease in blood sugar - is a major obstacle in the management of diabetes and prevention of long-term complications, and it may impose serious effects on the brain, including impairment of memory and other cognitive functions. This paper presents the development of a non-invasive sensor with miniaturized telemetry device in a wrist-watch for monitoring glucose concentration in blood. The sensor concept is based on optical chiralit of glucose level in the interstitial fluid. The wrist watch consists of a laser power source of the wavelength compatible with the glucose. A nanofilm with specific chirality is placed at the bottom of the watch. The light then passes through the film and illuminates a small area on the skin.It has been documented that there is certain concentration of sugar level is taken by the intertitial fluid from the blood stream and deposit a portion of it at the dead skin. The wrist-watch when in contact with the outer skin of the human will thus monitor the glucose concentration. A wireless monitoring system in the watch then downloads the data from the watch to a Palm or laptop computer.

THE INCIDENCE OF HYPERGLYCAEMIA IN VERY LOW BIRTH WEIGHT PRETERM NEWBORNS. RESULTS OF A CONTINUOUS GLUCOSE MONITORING STUDY--PRELIMINARY REPORT.

PubMed

Szymońska, Izabela; Jagła, Mateusz; Starzec, Katarzyna; Hrnciar, Katarzyna; Kwinta, Przemko

2015-01-01

To determine the incidence of hyperglycaemia in very low birth weight preterm newborns. To assess risk factors in hyperglycemia and outcome in groups of children with and without clinically significant hyperglycaemia. The prospective study included newborns with very low birth weight in whom the continuous glucose monitoring system was used for glucose measurements. A standardized hyperglycaemia treatment schedule was implemented and a uniform nutrition strategy introduced. The patients were divided into groups: group A--patients with under 5% of the readings over 150 mg/dL of glucose (control group), group B--patients with more than 5% of the readings over 150 mg/dL of glucose and under 5% of the readings over 180 mg/dL of glucose (mild hyperglycaemia), and group C--patients with over 5% of the readings > 180 mg/dL or on insulin treatment (moderate or severe hyperglycaemia). 63 patients were included in the study. Their mean gestational age was 27.7 weeks (SD:2.4), the mean birth weight was 1059g (SD: 262 g). Hyperglycaemia was detected in 27 (42.9%), including mild hyperglycaemia in 19 (30.2%), and moderate or severe hyperglycaemia in 8 (12.7%) neonates. Lower gestational age (p = 0.02) and higher CRIB IIscore (p < 0.01) were positively associated with hyperglycaemia. Early-onset sepsis (p < 0.01) was associated with higher glucose levels as well. A significantly higher mortality rate on the 28th day of life (p = 0.02), depending on the severity of hyperglycemia, was noted. No adverse effects related to the continuous glucose monitoring system were observed. The study confirmed the usefulness and safety of the continuous glucose monitoring system in VLBW neonates. A continuous glucose monitoring system should be used in neonatal intensive care units as a standard method.

Insulin-coated gold nanoparticles as a new concept for personalized and adjustable glucose regulation.

PubMed

Shilo, Malka; Berenstein, Peter; Dreifuss, Tamar; Nash, Yuval; Goldsmith, Guy; Kazimirsky, Gila; Motiei, Menachem; Frenkel, Dan; Brodie, Chaya; Popovtzer, Rachela

2015-12-28

Diabetes mellitus is a chronic metabolic disease, characterized by high blood glucose levels, affecting millions of people around the world. Currently, the main treatment for diabetes requires multiple daily injections of insulin and self-monitoring of blood glucose levels, which markedly affect patients' quality of life. In this study we present a novel strategy for controlled and prolonged glucose regulation, based on the administration of insulin-coated gold nanoparticles (INS-GNPs). We show that both intravenous and subcutaneous injection of INS-GNPs into a mouse model of type 1 diabetes decreases blood glucose levels for periods over 3 times longer than free insulin. We further showed that conjugation of insulin to GNPs prevented its rapid degradation by the insulin-degrading-enzyme, and thus allows controlled and adjustable bio-activity. Moreover, we assessed different sizes and concentrations of INS-GNPs, and found that both parameters have a critical effect in vivo, enabling specific adjustment of blood glucose levels. These findings have the potential to improve patient compliance in diabetes mellitus.

Insulin-coated gold nanoparticles as a new concept for personalized and adjustable glucose regulation

NASA Astrophysics Data System (ADS)

Shilo, Malka; Berenstein, Peter; Dreifuss, Tamar; Nash, Yuval; Goldsmith, Guy; Kazimirsky, Gila; Motiei, Menachem; Frenkel, Dan; Brodie, Chaya; Popovtzer, Rachela

2015-12-01

Diabetes mellitus is a chronic metabolic disease, characterized by high blood glucose levels, affecting millions of people around the world. Currently, the main treatment for diabetes requires multiple daily injections of insulin and self-monitoring of blood glucose levels, which markedly affect patients' quality of life. In this study we present a novel strategy for controlled and prolonged glucose regulation, based on the administration of insulin-coated gold nanoparticles (INS-GNPs). We show that both intravenous and subcutaneous injection of INS-GNPs into a mouse model of type 1 diabetes decreases blood glucose levels for periods over 3 times longer than free insulin. We further showed that conjugation of insulin to GNPs prevented its rapid degradation by the insulin-degrading-enzyme, and thus allows controlled and adjustable bio-activity. Moreover, we assessed different sizes and concentrations of INS-GNPs, and found that both parameters have a critical effect in vivo, enabling specific adjustment of blood glucose levels. These findings have the potential to improve patient compliance in diabetes mellitus.

In vivo glucose monitoring using dual-wavelength polarimetry to overcome corneal birefringence in the presence of motion.

PubMed

Pirnstill, Casey W; Malik, Bilal H; Gresham, Vincent C; Coté, Gerard L

2012-09-01

Over the past 35 years considerable research has been performed toward the investigation of noninvasive and minimally invasive glucose monitoring techniques. Optical polarimetry is one noninvasive technique that has shown promise as a means to ascertain blood glucose levels through measuring the glucose concentrations in the anterior chamber of the eye. However, one of the key limitations to the use of optical polarimetry as a means to noninvasively measure glucose levels is the presence of sample noise caused by motion-induced time-varying corneal birefringence. In this article our group presents, for the first time, results that show dual-wavelength polarimetry can be used to accurately detect glucose concentrations in the presence of motion-induced birefringence in vivo using New Zealand White rabbits. In total, nine animal studies (three New Zealand White rabbits across three separate days) were conducted. Using the dual-wavelength optical polarimetric approach, in vivo, an overall mean average relative difference of 4.49% (11.66 mg/dL) was achieved with 100% Zone A+B hits on a Clarke error grid, including 100% falling in Zone A. The results indicate that dual-wavelength polarimetry can effectively be used to significantly reduce the noise due to time-varying corneal birefringence in vivo, allowing the accurate measurement of glucose concentration in the aqueous humor of the eye and correlating that with blood glucose.

BioMEMS for multiparameter clinical monitoring

NASA Astrophysics Data System (ADS)

Moser, Isabella

2003-01-01

For diabetes patients glucose monitoring means an important improvement of their life quality and additionally it is a $3-billion-a-year business. Continuous glucose monitoring provides gapless glucose level control, an early warning of hypoglycemia, and is intended to control insulin pumps. An upgrading to multi-parameter monitoring would not only benefit patients with severe metabolism defects but also the metabolism of diabetes patient could be better controlled by monitoring an additional parameter like lactate. Multi-parameter monitoring devices are not commercially available, one of the complications in the integration of different biosensors using the same detecting molecule for all analytes is chemical cross talk between adjacent amperometric biosensors. Recently some integrated biosensors were published but either they were not mass producible or they were realized in an expensive silicon based technology. In addition to it most of them were not tested under monitoring conditions but their integration principles will be discussed. As an example a low cost multi- parameter microsystem and some applications of it in clinical diagnosis will be presented. Also an overlook of non-invasive methods and (minimal) invasive methods will be given with a focus on microdialysis.

Effect of repaglinide versus glimepiride on daily blood glucose variability and changes in blood inflammatory and oxidative stress markers.

PubMed

Yamazaki, Masahiro; Hasegawa, Goji; Majima, Saori; Mitsuhashi, Kazuteru; Fukuda, Takuya; Iwase, Hiroya; Kadono, Mayuko; Asano, Mai; Senmaru, Takafumi; Tanaka, Muhei; Fukui, Michiaki; Nakamura, Naoto

2014-01-01

Hemoglobin A1c is the main treatment target for patients with type 2 diabetes. It has also been shown recently that postprandial glucose and daily glucose fluctuations affect the progression of diabetic complications and atherosclerotic damages. Continuous glucose monitoring was performed in patients with type 2 diabetes to evaluate the efficacy of repaglinide vs. glimepiride on postprandial glucose spikes and fluctuations. A total of 10 Japanese patients with type 2 diabetes treated with glimepiride monotherapy were enrolled. After observation period for 8 weeks, glimepiride was changed to repaglinide. Continuous glucose monitoring was performed whilst consuming calorie-restricted diets for two days at baseline and at the end of the 12-week trial. Blood and urine samples were collected for measurement of glucose control parameters and inflammatory and oxidative stress markers on the last day of taking either glimepiride or repaglinide. Nine patients completed the trial. Although the glucose control parameters were not significantly different between glimepiride and repaglinide, the mean amplitude of glycemic excursions measured by continuous glucose monitoring was significantly reduced by changing treatment from glimepiride to repaglinide. The levels of plasminogen activator inhibitor-1, high sensitivity C-reactive protein, and urinary 8-hydoroxydeoxyguanosine were reduced significantly by repaglinide treatment. These results suggest that repaglinide may decrease the risk of cardiovascular disease in type 2 diabetes by minimizing glucose fluctuations thereby reducing inflammation and oxidative stress.

Effect of repaglinide versus glimepiride on daily blood glucose variability and changes in blood inflammatory and oxidative stress markers

PubMed Central

2014-01-01

Background Hemoglobin A1c is the main treatment target for patients with type 2 diabetes. It has also been shown recently that postprandial glucose and daily glucose fluctuations affect the progression of diabetic complications and atherosclerotic damages. Methods Continuous glucose monitoring was performed in patients with type 2 diabetes to evaluate the efficacy of repaglinide vs. glimepiride on postprandial glucose spikes and fluctuations. A total of 10 Japanese patients with type 2 diabetes treated with glimepiride monotherapy were enrolled. After observation period for 8 weeks, glimepiride was changed to repaglinide. Continuous glucose monitoring was performed whilst consuming calorie-restricted diets for two days at baseline and at the end of the 12-week trial. Blood and urine samples were collected for measurement of glucose control parameters and inflammatory and oxidative stress markers on the last day of taking either glimepiride or repaglinide. Results Nine patients completed the trial. Although the glucose control parameters were not significantly different between glimepiride and repaglinide, the mean amplitude of glycemic excursions measured by continuous glucose monitoring was significantly reduced by changing treatment from glimepiride to repaglinide. The levels of plasminogen activator inhibitor-1, high sensitivity C-reactive protein, and urinary 8-hydoroxydeoxyguanosine were reduced significantly by repaglinide treatment. Conclusion These results suggest that repaglinide may decrease the risk of cardiovascular disease in type 2 diabetes by minimizing glucose fluctuations thereby reducing inflammation and oxidative stress. PMID:24843385

Microdialysis Monitoring of CSF Parameters in Severe Traumatic Brain Injury Patients: A Novel Approach

PubMed Central

Thelin, Eric P.; Nelson, David W.; Ghatan, Per Hamid; Bellander, Bo-Michael

2014-01-01

Background: Neuro-intensive care following traumatic brain injury (TBI) is focused on preventing secondary insults that may lead to irreversible brain damage. Microdialysis (MD) is used to detect deranged cerebral metabolism. The clinical usefulness of the MD is dependent on the regional localization of the MD catheter. The aim of this study was to analyze a new method of continuous cerebrospinal fluid (CSF) monitoring using the MD technique. The method was validated using conventional laboratory analysis of CSF samples. MD-CSF and regional MD-Brain samples were correlated to patient outcome. Materials and Methods: A total of 14 patients suffering from severe TBI were analyzed. They were monitored using (1) a MD catheter (CMA64-iView, n = 7448 MD samples) located in a CSF-pump connected to the ventricular drain and (2) an intraparenchymal MD catheter (CMA70, n = 8358 MD samples). CSF-lactate and CSF-glucose levels were monitored and were compared to MD-CSF samples. MD-CSF and MD-Brain parameters were correlated to favorable (Glasgow Outcome Score extended, GOSe 6–8) and unfavorable (GOSe 1–5) outcome. Results: Levels of glucose and lactate acquired with the CSF-MD technique could be correlated to conventional levels. The median MD recovery using the CMA64 catheter in CSF was 0.98 and 0.97 for glucose and lactate, respectively. Median MD-CSF (CMA 64) lactate (p = 0.0057) and pyruvate (p = 0.0011) levels were significantly lower in the favorable outcome group compared to the unfavorable group. No significant difference in outcome was found using the lactate:pyruvate ratio (LPR), or any of the regional MD-Brain monitoring in our analyzed cohort. Conclusion: This new technique of global MD-CSF monitoring correlates with conventional CSF levels of glucose and lactate, and the MD recovery is higher than previously described. Increase in lactate and pyruvate, without any effect on the LPR, correlates to unfavorable outcome, perhaps related to the presence of erythrocytes in the CSF. PMID:25228896

Blood Glucose Levels in Diabetic Patients Following Corticosteroid Injections into the Subacromial Space of the Shoulder.

PubMed

Aleem, Alexander W; Syed, Usman Ali M; Nicholson, Thema; Getz, Charles L; Namdari, Surena; Beredjiklian, Pedro K; Abboud, Joseph A

2017-09-01

Corticosteroid injections are used to treat a variety of orthopedic conditions with the goal of decreasing pain and inflammation. Administration of systemic or local corticosteroids risks temporarily increasing blood glucose levels, especially diabetic patients. The purpose of this study is to quantify the effects of corticosteroid injections on blood glucose levels in diabetic patients with shoulder pathology. Diabetic patients who regularly monitored their blood glucose levels and were indicated for a subacromial corticosteroid injection were included in this prospective investigation. The typical normal morning fasting glucose and most recent hemoglobin A1c level was recorded for each patient. After injection, patients were contacted daily to confirm their fasting morning glucose level for 10 days post-injection. Seventeen consecutive patients were enrolled. Patients with hemoglobin A1c of <7% had an average rise in blood glucose of 38 mg/dL compared to 98 mg/dL in the poorly controlled group after injection ( P <0.001). Well-controlled patients' glucose levels returned to near baseline levels around post-injection day 8, while poorly controlled patients levels remained elevated. Similarly, insulin-dependent diabetic patients had an average increase in fasting glucose level of 99 mg/dL versus 50 mg/dL in non-insulin-dependent diabetic patients ( P <0.001). After corticosteroid injection, patients with well-controlled diabetes experience smaller elevations and faster return to baseline glucose levels than patients with poor control. Insulin dependent diabetics experienced similar findings as patients with poor control. Future studies are needed to evaluate dosing to optimize the risks of blood glucose elevation while maintaining therapeutic benefit.

Lifestyle may modify the glucose-raising effect of genetic loci. A study in the Greek population.

PubMed

Marouli, E; Kanoni, S; Dimitriou, M; Kolovou, G; Deloukas, P; Dedoussis, G

2016-03-01

Lifestyle habits including dietary intake and physical activity are closely associated with multiple body processes including glucose metabolism and are known to affect human health. Recent genome-wide association studies have identified several single nucleotide polymorphisms (SNPs) associated with glucose levels. The hypothesis tested here is whether a healthy lifestyle assessed via a score is associated with glycaemic traits and whether there is an interaction between the lifestyle and known glucose-raising genetic variants in association with glycaemic traits. Participants of Greek descent from the THISEAS study were included in this analysis. We developed a glucose preventive score (GPS) including dietary and physical activity characteristics. We also modelled a weighted genetic risk score (wGRS), based on 20 known glucose-raising loci, in order to investigate the impact of lifestyle-gene interaction on glucose levels. The GPS was observed to be significantly associated with lower glucose concentrations (β ± SE: -0.083 ± 0.021 mmol/L, P = 1.6 × 10(-04)) and the wGRS, as expected, with increased glucose levels (β ± SE: 0.020 ± 0.007 mmol/L, P = 8.4 × 10(-3)). The association of the wGRS with glucose levels was attenuated after interaction with the GPS. A higher GPS indicated decreasing glucose levels in the presence of an increasing wGRS (β interaction ± SE: -0.019 ± 0.007 mmol/L, P = 0.014). Our results indicate that lower glucose levels underlie a healthier lifestyle and also support an interaction between the wGRS for known glycaemic loci and GPS associated with lower glucose levels. These scores could be useful tools for monitoring glucose metabolism. Copyright © 2016. Published by Elsevier B.V.

Educational intervention together with an on-line quality control program achieve recommended analytical goals for bedside blood glucose monitoring in a 1200-bed university hospital.

PubMed

Sánchez-Margalet, Víctor; Rodriguez-Oliva, Manuel; Sánchez-Pozo, Cristina; Fernández-Gallardo, María Francisca; Goberna, Raimundo

2005-01-01

Portable meters for blood glucose concentrations are used at the patients bedside, as well as by patients for self-monitoring of blood glucose. Even though most devices have important technological advances that decrease operator error, the analytical goals proposed for the performance of glucose meters have been recently changed by the American Diabetes Association (ADA) to reach <5% analytical error and <7.9% total error. We studied 80 meters throughout the Virgen Macarena Hospital and we found most devices with performance error higher than 10%. The aim of the present study was to establish a new system to control portable glucose meters together with an educational program for nurses in a 1200-bed University Hospital to achieve recommended analytical goals, so that we could improve the quality of diabetes care. We used portable glucose meters connected on-line to the laboratory after an educational program for nurses with responsibilities in point-of-care testing. We evaluated the system by assessing total error of the glucometers using high- and low-level glucose control solutions. In a period of 6 months, we collected data from 5642 control samples obtained by 14 devices (Precision PCx) directly from the control program (QC manager). The average total error for the low-level glucose control (2.77 mmol/l) was 6.3% (range 5.5-7.6%), and even lower for the high-level glucose control (16.66 mmol/l), at 4.8% (range 4.1-6.5%). In conclusion, the performance of glucose meters used in our University Hospital with more than 1000 beds not only improved after the intervention, but the meters achieved the analytical goals of the suggested ADA/National Academy of Clinical Biochemistry criteria for total error (<7.9% in the range 2.77-16.66 mmol/l glucose) and optimal total error for high glucose concentrations of <5%, which will improve the quality of care of our patients.

A Human Serum-Based Enzyme-Free Continuous Glucose Monitoring Technique Using a Needle-Type Bio-Layer Interference Sensor

PubMed Central

Seo, Dongmin; Paek, Sung-Ho; Oh, Sangwoo; Seo, Sungkyu; Paek, Se-Hwan

2016-01-01

The incidence of diabetes is continually increasing, and by 2030, it is expected to have increased by 69% and 20% in underdeveloped and developed countries, respectively. Therefore, glucose sensors are likely to remain in high demand in medical device markets. For the current study, we developed a needle-type bio-layer interference (BLI) sensor that can continuously monitor glucose levels. Using dialysis procedures, we were able to obtain hypoglycemic samples from commercial human serum. These dialysis-derived samples, alongside samples of normal human serum were used to evaluate the utility of the sensor for the detection of the clinical interest range of glucose concentrations (70–200 mg/dL), revealing high system performance for a wide glycemic state range (45–500 mg/dL). Reversibility and reproducibility were also tested over a range of time spans. Combined with existing BLI system technology, this sensor holds great promise for use as a wearable online continuous glucose monitoring system for patients in a hospital setting. PMID:27669267

Noninvasive and Painless Urine Glucose Detection by Using Computer-based Polarimeter

NASA Astrophysics Data System (ADS)

Sutrisno; Laksono, Y. A.; Hidayat, N.

2017-05-01

Diabetes kills millions of people worldwide each year. It challenges us as researchers to give contribution in early diagnosis to ensure a healthy life. As a matter of fact, common glucose testing devices that have been widely used so far are, at least, glucose meter and urine glucose test strip. The glucose meter ordinarily requires blood taken from patient’s finger. The glucose test strip uses patient’s urine but records unspecific urine glucose level, since the strip only provides the glucose level in some particular ranges. Instead of detecting the glucose level in blood and using the non-specific technique, a noninvasive and painless technique that can detect glucose level accurately will provide a more feasible approach for diabetes diagnosis. The noninvasive and painless urine glucose level monitoring by means of computer-based polarimeter is presented in this paper. The instrument consisted of a power source, a sample box, a light sensor, a polarizer, an analyzer, an analog to digital converter (ADC), and a computer. The concentration of urine glucose concentration was evaluated from the curve of the change in detected optical rotation angle and output potential by the computer-based polarimeter. Statistical analyses by means of Gaussian fitting and linear regression were applied to investigate the rotation angle and urine glucose concentration, respectively. From our experiment, the urine glucose level, measured by glucose test strips, of the normal patient was 100 mg/dl, and the diabetic patient was 500 mg/dl. Our polarimeter even read more precise values for the urine glucose concentrations of those normal and diabetic of the same patients, i.e. 50.61 mg/dl and 502.41 mg/dl, respectively. In other words, the results showed that our polarimeter was able to quantitatively measure the urine glucose level more accurate than urine glucose test strips. Hence, this computer-based polarimeter could be used as an alternative for early detection of urine glucose with noninvasive and painless characteristics.

Differential effects of vildagliptin and glimepiride on glucose fluctuations in patients with type 2 diabetes mellitus assessed using continuous glucose monitoring.

PubMed

He, Y L; Foteinos, G; Neelakantham, S; Mattapalli, D; Kulmatycki, K; Forst, T; Taylor, A

2013-12-01

To assess whether there is a difference in the effects of vildagliptin and glimepiride on glucose fluctuation in patients with type 2 diabetes mellitus (T2DM) using continuous glucose monitoring (CGM). This was an open-label, randomized cross-over study conducted in T2DM patients. A total of 24 patients (age: 58.3 ± 5.56 years, baseline HbA1c: 7.6 ± 0.50%) who were on stable metformin monotherapy (500-3000 mg) were enrolled, and all completed the study. Each patient received two 5-day treatments (vildagliptin 50 mg b.i.d. or glimepiride 2 mg q.d.) in a cross-over manner. Various biomarkers and blood glucose concentrations were measured following breakfast. The 24-h glucose profiles were also measured using the CGM device at baseline and after 5 days of treatment, and fluctuations in glucose levels were estimated from CGM data. Both vildagliptin and glimepiride reduced postprandial glucose levels, based on both CGM data (15% vs. 16%) and measured plasma glucose (13% vs.17%). Vildagliptin showed lower glucose fluctuations than glimepiride as measured by mean amplitude of glycaemic excursions (MAGE, p = 0.1076), standard deviation (s.d., p = 0.1346) of blood glucose rate of change, but did not reach statistical significance attributed to the small sample size. MAGE was reduced by ∼20% with vildagliptin versus glimepiride. Vildagliptin led to statistically significant lowering of the rate of change in the median curve (RCMC) and interquartile range (IQR) of glucose. Treatment with vildagliptin significantly increased the levels of active glucagon-like peptide-1 by 2.36-fold (p ≤ 0.0001) and suppressed glucagon by 8% (p = 0.01), whereas glimepiride significantly increased the levels of insulin and C-peptide by 21% (p = 0.012) and 12% (p = 0.003), respectively. Vildagliptin treatment was associated with less fluctuation of glucose levels than glimepiride treatment as assessed by 24-h CGM device, suggesting vildagliptin may have the potential to offer long-term beneficial effects for patients with T2DM in preventing the development of complications of diabetes. © 2013 John Wiley & Sons Ltd.

Self monitoring of glucose by people with diabetes: evidence based practice.

PubMed Central

Gallichan, M.

1997-01-01

The inappropriate use of self monitoring of glucose is wasteful of NHS resources and can cause psychological harm. Although a few patients find that self monitoring enables them to understand and take control of their diabetes, many people with diabetes are performing inaccurate or unnecessary tests. There is no convincing evidence that self monitoring improves glycaemic control, nor that blood testing is necessarily better than urine testing. It may be appropriate for some patients not to monitor their own glucose but to rely instead on regular laboratory estimations of glycaemic control. Glucose self monitoring should be performed only when it serves an identified purpose. It is widely assumed that glucose self monitoring, preferably of blood glucose concentrations, is desirable or even essential for everyone with diabetes. It is common for patients who have previously tested their urine, or have done no glucose monitoring at home, to be taught to measure their blood glucose when they are admitted to hospital. In the community too, patients are often encouraged to monitor their blood glucose, and newly diagnosed patients of all ages are usually taught to measure their blood glucose concentrations. Self monitoring can sometimes be useful, but evidence is mounting that its indiscriminate use is of questionable value. In 1995, Pounds 42.6 million was spent on home monitoring of glucose in the United Kingdom (Intercontinental Medical Statistics, personal communication). Is this enormous cost justified? Is blood testing necessarily better than urine testing? Is glucose self monitoring always necessary, or is it sometimes a waste of time and money? Are recommendations for self monitoring based on sound evidence? PMID:9099125

[Effect of CPAP therapy on dynamic glucose level in OSAHS patients with newly diagnosed T2DM].

PubMed

Zhao, Lijun; Hui, Peilin; Xie, Yuping; Hou, Yiping; Wei, Xiaoquan; Ma, Wei; Wang, Jinfeng; Zhou, Liya; Zhang, Wenjuan

2015-11-24

To investigate the characteristic of dynamic glucose level in obstructive sleep apnea-hypopnea syndrome (OSAHS) patients with newly diagnosed type 2 diabetes mellitus (T2DM) and to evaluate the effect of continuous positive airway pressure (CPAP) treatment on the glucose level. A total of 65 cases of patients with T2DM who were newly diagnosed by oral glucose tolerance test (OGTT) were enrolled from April 2014 to April 2015 in Gansu Provincial Hospital, and divided into simple T2DM group (n=30) and OSAHS with T2DM group (n=35) according to aponea-hypopnea index (AHI) which was monitored by polysomnography (PSG). Their general clinical data were collected, and glucose level of different periods was monitored by continuous glucose moitoring system (CGMS). Changes of glucose level were compared between two groups before and after CPAP treatment. Age, gender proportion, BMI, smoking and drinking history, glycosylated hemoglobin (HbA1c) and blood lipid profile had no significantly difference between two groups. Longer neck circumstance and higher waist-hip ration (WHR), higher systolic blood pressure and diastolic blood pressure, higher fasting plasma glucose (FPG) [(9.4 ± 3.2) vs (7.3 ± 2.1) mmol/L, P=0.028] and fasting insulin (FINS) [(19.2 ± 8.7) vs (11.1 ± 4.7) mU/L, P=0.044] level, more serious homeostasis model assessment insulin resistance (HOMA-IR) were found in OSAHS patients with T2DM when compared to patients in simple T2DM group. The average dynamic glucose level of 24 hours, daytime, nocturnal and sleep time in OSAHS with T2DM group were higher than that in the simple T2DM group (all P<0.05). The alarming times when the average dynamic glucose level of nocturnal time was more than 0.1 mmol·L⁻¹·min⁻¹ in T2DM with OSAHS was more than that in control group (P=0.001). After treatment of CPAP, the level of AHI [(5.9 ± 3.6) vs (56.7 ± 11.4) times/h, P<0.001], average dynamic glucose level of 24 hours, day, nocturnal and sleep time were obviously decreased (all P<0.05); lowest saturation oxygen (LSpO₂) was significantly increased [(92.3 ± 3.7)% vs (81.5 ± 20.2)%, P<0.001]; the alarming times and HOMA-IR were obviously decreased (P=0.019, 0.043). According to multiple linear regression analysis, the AHI (β=0.736, P<0.001) in OSAHS with T2DM group was positively related to the average dynamic glucose level during sleep time, but the LSpO₂(β=-0.889, P<0.001) was negatively correlated. OSAHS patients with newly diagnosed T2DM have higher glucose level than that in simple T2DM patients, and CPAP therapy can obviously decrease the glucose level in newly diagnosed T2DM patients with OSAHS. AHI and LSpO₂may influence the average dynamic glucose level during sleep time.

First clinical evaluation of a new percutaneous optical fiber glucose sensor for continuous glucose monitoring in diabetes.

PubMed

Müller, Achim Josef; Knuth, Monika; Nikolaus, Katharina Sibylle; Krivánek, Roland; Küster, Frank; Hasslacher, Christoph

2013-01-01

This article describes a new fiber-coupled, percutaneous fluorescent continuous glucose monitoring (CGM) system that has shown 14 days of functionality in a human clinical trial. The new optical CGM system (FiberSense) consists of a transdermal polymer optical fiber containing a biochemical glucose sensor and a small fluorescence photometer optically coupled to the fiber. The glucose-sensitive optical fiber was implanted in abdominal and upper-arm subcutaneous tissue of six diabetes patients and remained there for up to 14 days. The performance of the system was monitored during six visits to the study center during the trial. Blood glucose changes were induced by oral carbohydrate intake and insulin injections, and capillary blood glucose samples were obtained from the finger tip. The data were analyzed using linear regression and the consensus error grid analysis. The FiberSense worn at the upper arm exhibited excellent results during 14 wearing days, with an overall mean absolute relative difference (MARD) of 8.3% and 94.6% of the data in zone A of the consensus error grid. At the abdominal application site, FiberSense resulted in a MARD of 11.4 %, with 93.8% of the data in zone A. The FiberSense CGM system provided consistent, reliable measurements of subcutaneous glucose levels in human clinical trial patients with diabetes for up to 14 days. © 2013 Diabetes Technology Society.

Continuous glucose monitoring systems for type 1 diabetes mellitus.

PubMed

Langendam, Miranda; Luijf, Yoeri M; Hooft, Lotty; Devries, J Hans; Mudde, Aart H; Scholten, Rob J P M

2012-01-18

Self-monitoring of blood glucose is essential to optimise glycaemic control in type 1 diabetes mellitus. Continuous glucose monitoring (CGM) systems measure interstitial fluid glucose levels to provide semi-continuous information about glucose levels, which identifies fluctuations that would not have been identified with conventional self-monitoring. Two types of CGM systems can be defined: retrospective systems and real-time systems. Real-time systems continuously provide the actual glucose concentration on a display. Currently, the use of CGM is not common practice and its reimbursement status is a point of debate in many countries. To assess the effects of CGM systems compared to conventional self-monitoring of blood glucose (SMBG) in patients with diabetes mellitus type 1. We searched The Cochrane Library, MEDLINE, EMBASE and CINAHL for the identification of studies. Last search date was June 8, 2011. Randomised controlled trials (RCTs) comparing retrospective or real-time CGM with conventional self-monitoring of blood glucose levels or with another type of CGM system in patients with type 1 diabetes mellitus. Primary outcomes were glycaemic control, e.g. level of glycosylated haemoglobin A1c (HbA1c) and health-related quality of life. Secondary outcomes were adverse events and complications, CGM derived glycaemic control, death and costs. Two authors independently selected the studies, assessed the risk of bias and performed data-extraction. Although there was clinical and methodological heterogeneity between studies an exploratory meta-analysis was performed on those outcomes the authors felt could be pooled without losing clinical merit. The search identified 1366 references. Twenty-two RCTs meeting the inclusion criteria of this review were identified. The results of the meta-analyses (across all age groups) indicate benefit of CGM for patients starting on CGM sensor augmented insulin pump therapy compared to patients using multiple daily injections of insulin (MDI) and standard monitoring blood glucose (SMBG). After six months there was a significant larger decline in HbA1c level for real-time CGM users starting insulin pump therapy compared to patients using MDI and SMBG (mean difference (MD) in change in HbA1c level -0.7%, 95% confidence interval (CI) -0.8% to -0.5%, 2 RCTs, 562 patients, I(2)=84%). The risk of hypoglycaemia was increased for CGM users, but CIs were wide and included unity (4/43 versus 1/35; RR 3.26, 95% CI 0.38 to 27.82 and 21/247 versus 17/248; RR 1.24, 95% CI 0.67 to 2.29). One study reported the occurrence of ketoacidosis from baseline to six months; there was however only one event. Both RCTs were in patients with poorly controlled diabetes.For patients starting with CGM only, the average decline in HbA1c level six months after baseline was also statistically significantly larger for CGM users compared to SMBG users, but much smaller than for patients starting using an insulin pump and CGM at the same time (MD change in HbA1c level -0.2%, 95% CI -0.4% to -0.1%, 6 RCTs, 963 patients, I(2)=55%). On average, there was no significant difference in risk of severe hypoglycaemia or ketoacidosis between CGM and SMBG users. The confidence interval however, was wide and included a decreased as well as an increased risk for CGM users compared to the control group (severe hypoglycaemia: 36/411 versus 33/407; RR 1.02, 95% CI 0.65 to 1.62, 4 RCTs, I(2)=0% and ketoacidosis: 8/411 versus 8/407; RR 0.94, 95% CI 0.36 to 2.40, 4 RCTs, I(2)=0%).Health-related quality of life was reported in five of the 22 studies. In none of these studies a significant difference between CGM and SMBG was found. Diabetes complications, death and costs were not measured.There were no studies in pregnant women with diabetes type 1 and in patients with hypoglycaemia unawareness. There is limited evidence for the effectiveness of real-time continuous glucose monitoring (CGM) use in children, adults and patients with poorly controlled diabetes. The largest improvements in glycaemic control were seen for sensor-augmented insulin pump therapy in patients with poorly controlled diabetes who had not used an insulin pump before. The risk of severe hypoglycaemia or ketoacidosis was not significantly increased for CGM users, but as these events occurred infrequent these results have to be interpreted cautiously.There are indications that higher compliance of wearing the CGM device improves glycosylated haemoglobin A1c level (HbA1c) to a larger extent. 

Steroid injection for shoulder pain causes prolonged increased glucose level in type 1 diabetics

PubMed Central

Povlsen, Bo; Povlsen, Sebastian D

2014-01-01

Shoulder pain is very common in diabetic patients and often treated with steroid injections, with subsequent increases in blood glucose levels or the need for additional insulin being questioned. We report a case of significant and prolonged elevation of blood glucose levels and resultant insulin requirement in a type 1 diabetic man after a single 40 mg injection of triamcinolone for shoulder pain. Within 48 h, the shoulder pain as assessed by a visual analogue scale (0–10) was reduced to zero, but the elevated insulin requirements continued for 4 weeks after the injection. This finding suggests that steroid injections for shoulder pain in diabetics may not always be as safe as previously thought. We propose that medical practitioners advise their patients to monitor their glucose levels more carefully after such injections and that caution is exercised when considering administrating these injections to those who have poorly controlled blood glucose levels preinjection to avoid ketoacidosis. PMID:25199186

Steroid injection for shoulder pain causes prolonged increased glucose level in type 1 diabetics.

PubMed

Povlsen, Bo; Povlsen, Sebastian D

2014-09-08

Shoulder pain is very common in diabetic patients and often treated with steroid injections, with subsequent increases in blood glucose levels or the need for additional insulin being questioned. We report a case of significant and prolonged elevation of blood glucose levels and resultant insulin requirement in a type 1 diabetic man after a single 40 mg injection of triamcinolone for shoulder pain. Within 48 h, the shoulder pain as assessed by a visual analogue scale (0-10) was reduced to zero, but the elevated insulin requirements continued for 4 weeks after the injection. This finding suggests that steroid injections for shoulder pain in diabetics may not always be as safe as previously thought. We propose that medical practitioners advise their patients to monitor their glucose levels more carefully after such injections and that caution is exercised when considering administrating these injections to those who have poorly controlled blood glucose levels preinjection to avoid ketoacidosis. 2014 BMJ Publishing Group Ltd.

Effect of Financial Incentives on Glucose Monitoring Adherence and Glycemic Control Among Adolescents and Young Adults With Type 1 Diabetes: A Randomized Clinical Trial.

PubMed

Wong, Charlene A; Miller, Victoria A; Murphy, Kathryn; Small, Dylan; Ford, Carol A; Willi, Steven M; Feingold, Jordyn; Morris, Alexander; Ha, Yoonhee P; Zhu, Jingsan; Wang, Wenli; Patel, Mitesh S

2017-12-01

Glycemic control often deteriorates during adolescence and the transition to young adulthood for patients with type 1 diabetes. The inability to manage type 1 diabetes effectively during these years is associated with poor glycemic control and complications from diabetes in adult life. To determine the effect of daily financial incentives on glucose monitoring adherence and glycemic control in adolescents and young adults with type 1 diabetes. The Behavioral Economic Incentives to Improve Glycemic Control Among Adolescents and Young Adults With Type 1 Diabetes (BE IN CONTROL) study was an investigator-blinded, 6-month, 2-arm randomized clinical trial conducted between January 22 and November 2, 2016, with 3-month intervention and follow-up periods. Ninety participants (aged 14-20) with suboptimally controlled type 1 diabetes (hemoglobin A1c [HbA1c] >8.0%) were recruited from the Diabetes Center for Children at the Children's Hospital of Philadelphia. All participants were given daily blood glucose monitoring goals of 4 or more checks per day with 1 or more level within the goal range (70-180 mg/dL) collected with a wireless glucometer. The 3-month intervention consisted of a $60 monthly incentive in a virtual account, from which $2 was subtracted for every day of nonadherence to the monitoring goals. During a 3-month follow-up period, the intervention was discontinued. The primary outcome was change in HbA1c levels at 3 months. Secondary outcomes included adherence to glucose monitoring and change in HbA1c levels at 6 months. All analyses were by intention to treat. Of the 181 participants screened, 90 (52 [57.8%] girls) were randomized to the intervention (n = 45) or control (n = 45) arms. The mean (SD) age was 16.3 (1.9) years. The intervention group had significantly greater adherence to glucose monitoring goals in the incentive period (50.0% vs 18.9%; adjusted difference, 27.2%; 95% CI, 9.5% to 45.0%; P = .003) but not in the follow-up period (15.3% vs 8.7%; adjusted difference, 3.9%; 95% CI, -2.0% to 9.9%; P = .20). The change in HbA1c levels from baseline did not differ significantly between groups at 3 months (adjusted difference, -0.08%; 95% CI, -0.69% to 0.54%; P = .80) or 6 months (adjusted difference, 0.03%; 95% CI, -0.55% to 0.60%; P = .93). Among adolescents and young adults with type 1 diabetes, daily financial incentives improved glucose monitoring adherence during the incentive period but did not significantly improve glycemic control. clinicaltrials.gov Identifier: NCT02568501.

Effect of intrapleural oxytocin injection on blood glucose level in rat (rattus norvegicous).

PubMed

Dezhkam, Y; Dezhkam, N

2014-01-01

The effect of Oxytocin on energy metabolism is still question. The aim of the present study was to investigate the effect of exogenous oxytocin injection in different dose and timetable on blood glucose level in rat. In this study 16 adult female rats were divided into 2 groups (Treatment 1(T1) and Treatment 2(T2)). T1 with 8 adult female rats received 0.2 IU/Kg oxytocin via intrapleural (IP) and blood glucose level was tested at 0th, 20th, 40th and 60th min after injection by collecting the blood from jugular vein. In T2 eight female rats received 0.4 IU/kg oxytocin via IP taking blood glucose measure at the same minutes as T1. The experiment tested in three replicates. Blood glucose meter (Model: 3TMSO1G) was used with glucose smart blood glucose monitoring system to the measurement of blood glucose level in rats. Data were analyzed using the GLM procedure of SAS (SAS, version 9) PDIFF was used to compare least square means among treatments adjusting by tukey test. There were hypoglycemic tendency in the changes of the blood glucose level in both T1 and T2, 20th min after injection (88.79 ± 3.28, 68.58 ± 3.63, respectively), while in the remaining subjects (4th and 60th min) blood glucose level increased (115.54 ± 4, 79.7 ± 2.09 and 136.33 ± 5.8, 123.54 ± 0.9, respectively). These results showed that blood glucose level in T1 significantly higher than T2 (p < 0.0001). These in vivo results showed that exogenous oxytocin can be good choice to decrease the blood glucose level very fast.

Glycaemic control and self-management behaviours in Type 2 diabetes: results from a 1-year longitudinal cohort study.

PubMed

Houle, J; Beaulieu, M-D; Chiasson, J-L; Lespérance, F; Côté, J; Strychar, I; Bherer, L; Meunier, S; Lambert, J

2015-09-01

To better understand the associations between changes in self-management behaviours and glycaemic control. We conducted a prospective observational study of 295 adult patients with Type 2 diabetes evaluated at baseline, 6 and 12 months. Four self-management behaviours were evaluated using the Summary of Diabetes Self-Care Activities instrument, which assesses healthy diet, physical activity, medication taking and self-monitoring of blood glucose. Using hierarchical linear regression models, we tested whether changes in self-management behaviours were associated with short-term (6-month) or long-term (12-month) changes in glycaemic control, after controlling for demographic and clinical characteristics. Improved diet was associated with a decrease in HbA1c level, both at 6 and 12 months. Improved medication taking was associated with short-term improvement in glycaemic control, while increased self-monitoring of blood glucose frequency was associated with a 12-month improvement in HbA1c . Completely stopping exercise after being physically active at baseline was associated with a rise in HbA1c level at 6-month follow-up. Interaction analysis indicated that a healthy diet benefitted all participant subgroups, but that medication taking was associated with glycaemic control only for participants living in poverty and more strongly for those with lower educational levels. Finally, a higher self-monitoring of blood glucose frequency was associated with better glycaemic control only in insulin-treated participants. Even after adjusting for potential confounders (including baseline HbA1c ), increased frequency of healthy diet, medication taking and self-monitoring of blood glucose were associated with improved HbA1c levels. These self-management behaviours should be regularly monitored to identify patients at risk of deterioration in glycaemic control. Barriers to optimum self-management should be removed, particularly among socio-economically disadvantaged populations. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Proton mediated control of biochemical reactions with bioelectronic pH modulation

DOE PAGES

Deng, Yingxin; Miyake, Takeo; Keene, Scott; ...

2016-04-07

In Nature, protons (H +) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H + channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H + currents and H + concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H + between PdH x contacts and solution. The present transducer records bistable pH modulation from an “enzymaticmore » flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. Furthermore, the transducer also controls bioluminescence from firefly luciferase by affecting solution pH.« less

Proton mediated control of biochemical reactions with bioelectronic pH modulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Yingxin; Miyake, Takeo; Keene, Scott

In Nature, protons (H +) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H + channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H + currents and H + concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H + between PdH x contacts and solution. The present transducer records bistable pH modulation from an “enzymaticmore » flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. Furthermore, the transducer also controls bioluminescence from firefly luciferase by affecting solution pH.« less

Can Glucose Be Monitored Accurately at the Site of Subcutaneous Insulin Delivery?

PubMed Central

Castle, Jessica R.; Jacobs, Peter G.; Cargill, Robert S.

2014-01-01

Because insulin promotes glucose uptake into adipocytes, it has been assumed that during measurement of glucose at the site of insulin delivery, the local glucose level would be much lower than systemic glucose. However, recent investigations challenge this notion. What explanations could account for a reduced local effect of insulin in the subcutaneous space? One explanation is that, in humans, the effect of insulin on adipocytes appears to be small. Another is that insulin monomers and dimers (from hexamer disassociation) might be absorbed into the circulation before they can increase glucose uptake locally. In addition, negative cooperativity of insulin action (a lower than expected effect of very high insulin concentrations)may play a contributing role. Other factors to be considered include dilution of interstitial fluid by the insulin vehicle and the possibility that some of the local decline in glucose might be due to the systemic effect of insulin. With regard to future research, redundant sensing units might be able to quantify the effects of proximity, leading to a compensatory algorithm. In summary, when measured at the site of insulin delivery, the decline in subcutaneous glucose level appears to be minimal, though the literature base is not large. Findings thus far support (1) the development of integrated devices that monitor glucose and deliver insulin and (2) the use of such devices to investigate the relationship between subcutaneous delivery of insulin and its local effects on glucose. A reduction in the number of percutaneous devices needed to manage diabetes would be welcome. PMID:24876621

Sensor-Augmented Insulin Pumps and Hypoglycemia Prevention in Type 1 Diabetes.

PubMed

Steineck, Isabelle; Ranjan, Ajenthen; Nørgaard, Kirsten; Schmidt, Signe

2017-01-01

Hypoglycemia can lead to seizures, unconsciousness, or death. Insulin pump treatment reduces the frequency of severe hypoglycemia compared with multiple daily injections treatment. The addition of a continuous glucose monitor, so-called sensor-augmented pump (SAP) treatment, has the potential to further limit the duration and severity of hypoglycemia as the system can detect and in some systems act on impending and prevailing low blood glucose levels. In this narrative review we summarize the available knowledge on SAPs with and without automated insulin suspension, in relation to hypoglycemia prevention. We present evidence from randomized trials, observational studies, and meta-analyses including nonpregnant individuals with type 1 diabetes mellitus. We also outline concerns regarding SAPs with and without automated insulin suspension. There is evidence that SAP treatment reduces episodes of moderate and severe hypoglycemia compared with multiple daily injections plus self-monitoring of blood glucose. There is some evidence that SAPs both with and without automated suspension reduces the frequency of severe hypoglycemic events compared with insulin pumps without continuous glucose monitoring.

Protective coating and hyperthermal atomic oxygen texturing of optical fibers used for blood glucose monitoring

NASA Technical Reports Server (NTRS)

Banks, Bruce A. (Inventor)

2008-01-01

Disclosed is a method of producing cones and pillars on polymethylmethacralate (PMMA) optical fibers for glucose monitoring. The method, in one embodiment, consists of using electron beam evaporation to deposit a non-contiguous thin film of aluminum on the distal ends of the PMMA fibers. The partial coverage of aluminum on the fibers is randomly, but rather uniformly distributed across the end of the optical fibers. After the aluminum deposition, the ends of the fibers are then exposed to hyperthermal atomic oxygen, which oxidizes the areas that are not protected by aluminum. The resulting PMMA fibers have a greatly increased surface area and the cones or pillars are sufficiently close together that the cellular components in blood are excluded from passing into the valleys between the cones and pillars. The optical fibers are then coated with appropriated surface chemistry so that they can optically sense the glucose level in the blood sample than that with conventional glucose monitoring.

Label-free glucose detection using cantilever sensor technology based on gravimetric detection principles.

PubMed

Hsieh, Shuchen; Hsieh, Shu-Ling; Hsieh, Chiung-Wen; Lin, Po-Chiao; Wu, Chun-Hsin

2013-01-01

Efficient maintenance of glucose homeostasis is a major challenge in diabetes therapy, where accurate and reliable glucose level detection is required. Though several methods are currently used, these suffer from impaired response and often unpredictable drift, making them unsuitable for long-term therapeutic practice. In this study, we demonstrate a method that uses a functionalized atomic force microscope (AFM) cantilever as the sensor for reliable glucose detection with sufficient sensitivity and selectivity for clinical use. We first modified the AFM tip with aminopropylsilatrane (APS) and then adsorbed glucose-specific lectin concanavalin A (Con A) onto the surface. The Con A/APS-modified probes were then used to detect glucose by monitoring shifts in the cantilever resonance frequency. To confirm the molecule-specific interaction, AFM topographical images were acquired of identically treated silicon substrates which indicated a specific attachment for glucose-Con A and not for galactose-Con A. These results demonstrate that by monitoring the frequency shift of the AFM cantilever, this sensing system can detect the interaction between Con A and glucose, one of the biomolecule recognition processes, and may assist in the detection and mass quantification of glucose for clinical applications with very high sensitivity.

Both the frequency of HbA1c testing and the frequency of self-monitoring of blood glucose predict metabolic control: A multicentre analysis of 15 199 adult type 1 diabetes patients from Germany and Austria.

PubMed

Schwandt, A; Best, F; Biester, T; Grünerbel, A; Kopp, F; Krakow, D; Laimer, M; Wagner, C; Holl, R W

2017-10-01

The objective of this study was to examine the association between metabolic control and frequency of haemoglobin A 1c (HbA 1c ) measurements and of self-monitoring of blood glucose, as well as the interaction of both. Data of 15 199 adult type 1 diabetes patients registered in a standardized electronic health record (DPV) were included. To model the association between metabolic control and frequency of HbA 1c testing or of self-monitoring of blood glucose, multiple hierarchic regression models with adjustment for confounders were fitted. Tukey-Kramer test was used to adjust P values for multiple comparisons. Vuong test was used to compare non-nested models. The baseline variables of the study population were median age 19.9 [Q1; Q3: 18.4; 32.2] years and diabetes duration 10.4 [6.8; 15.7] years. Haemoglobin A 1c was 60.4 [51.5; 72.5] mmol/mol. Frequency of HbA 1c testing was 8.0 [5.0; 9.0] within 2 years, and daily self-monitoring of blood glucose frequency was 5.0 [4.0; 6.0]. After adjustment, a U-shaped association between metabolic control and frequency of HbA 1c testing was observed with lowest HbA 1c levels in the 3-monthly HbA 1c testing group. There was an inverse relationship between self-monitoring of blood glucose and HbA 1c with lower HbA 1c associated with highest frequency of testing (>6 daily measurements). Quarterly HbA 1c testing and frequent self-monitoring of blood glucose were associated with best metabolic control. The adjusted Vuong Z statistic suggests that metabolic control might be better explained by HbA 1c testing compared to self-monitoring of blood glucose (P < .0001). This research reveals the importance of quarterly clinical HbA 1c monitoring together with frequent self-monitoring of blood glucose in diabetes management to reach and maintain target HbA 1c . Copyright © 2017 John Wiley & Sons, Ltd.

Multiday Fully Closed Loop Insulin Delivery in Monitored Outpatient Conditions

ClinicalTrials.gov

2014-04-29

To Demonstrate That the Closed Loop System Can be Used Safely Over a Few Consecutive Days.; To Assess Effectiveness in Maintaining Patients' Glucose Levels in the Target Range of 70 to 180 mg/dl, Measured by Blood Glucose Sensor.; To Evaluate the User Experience With a Closed Loop System

A portable measuring system for a competitive binding glucose biosensor

NASA Astrophysics Data System (ADS)

Colvin, Lydia E.; Means, A. Kristen; Grunlan, Melissa A.; Coté, Gerard L.

2018-02-01

Central to minimizing the long- and short-term complications associated with diabetes is careful monitoring and maintenance of blood glucose at normal levels. Towards replacing conventionally used finger-prick glucose testing, indwelling continuous glucose monitors (CGMs) based on amperometric electrodes have been introduced to the market. Envisioned to lead to a CGM with an increased lifetime, we report herein a fluorescently-labeled competitive binding assay contained within a hydrogel membrane whose glucose response is measured via a novel portable system. The optical system design included a laser source, bifurcated fiber, laser filter and simple fiber coupled spectrometer to obtain the change in FRET pair ratio of the assay. Glucose response of the assay in free solution was measured using this system across the physiologic range (0-200 mg/dL). The FRET pair ratio signal was seen to increase with glucose and the standard error of calibration was 22.42 mg/dL with a MARD value of 14.85%. When the assay was contained within the hydrogel membrane's central cavity and similarly analyzed, the standard error increased but the assay maintained its reversibility.

Nanostructured fluorescent particles for glucose sensing

NASA Astrophysics Data System (ADS)

Grant, Patrick S.; Fang, Ming; Lvov, Yuri; McShane, Michael J.

2002-05-01

Self-assembled thin films containing embedded enzymes and fluorescent indicators are being developed for use as highly specific glucose biosensors. The sensors are fabricated using electrostatic Layer-by-Layer (LBL) adsorption to create oxygen-sensitive (Ruthenium-based) layers, the fluorescent intensity of which responds to changes in local oxygen levels. Oxygen is consumed locally by the reaction between glucose oxidase (GOx) molecules and glucose. Latex particles serve as the templates for our sensors and fabrication is carried out through the alternate adsorption of multiple levels of {GOx/polycation} and {Ruthenium-polycation/polyanion} bilayers. Additional fluorescence layers as well as fluorescent latex are being considered as internal intensity references to allow ratiometric monitoring. Films adsorbed to the nanoparticle templates are being studied to understand the fundamental chemical and optical properties, including enzymatic activity, spectral shape and emission intensity. Enzymatic activity is retained and stability is improved after adsorption, and increased surface area afforded by the particles allows use of increased numbers of molecules. Fluorescence is also maintained, though blue shifts are observed in emission spectra, and indicator activity remains. In vitro characterization studies demonstrate the feasibility of the particles as glucose biosensors, and future work will aim to optimize the response for neural monitoring.

Closed-loop controlled noninvasive ultrasonic glucose sensing and insulin delivery

NASA Astrophysics Data System (ADS)

Park, Eun-Joo; Werner, Jacob; Jaiswal, Devina; Smith, Nadine Barrie

2010-03-01

To prevent complications in diabetes, the proper management of blood glucose levels is essential. Previously, ultrasonic transdermal methods using a light-weight cymbal transducer array has been studied for noninvasive methods of insulin delivery for Type-1 diabetes and glucose level monitoring. In this study, the ultrasound systems of insulin delivery and glucose sensing have been combined by a feedback controller. This study was designed to show the feasibility of the feedback controlled ultrasound system for the noninvasive glucose control. For perspective human application, in vivo experiments were performed on large animals that have a similar size to humans. Four in vivo experiments were performed using about 200 lbs pigs. The cymbal array of 3×3 pattern has been used for insulin delivery at 30 kHz with the spatial-peak temporal-peak intensity (Isptp) of 100 mW/cm2. For glucose sensing, a 2×2 array was operated at 20 kHz with Isptp = 100 mW/cm2. Based on the glucose level determined by biosensors after the ultrasound exposure, the ultrasound system for the insulin delivery was automatically operated. The glucose level of 115 mg/dl was set as a reference value for operating the insulin delivery system. For comparison, the glucose levels of blood samples collected from the ear vein were measured by a commercial glucose meter. Using the ultrasound system operated by the close-loop, feed-back controller, the glucose levels of four pigs were determined every 20 minutes and continuously controlled for 120 minutes. In comparison to the commercial glucose meter, the glucose levels determined by the biosensor were slightly higher. The results of in vivo experiments indicate the feasibility of the feedback controlled ultrasound system using the cymbal array for noninvasive glucose sensing and insulin delivery. Further studies on the extension of the glucose control will be continued for the effective method of glucose control.

Glucose concentration measured by the hybrid coherent anti-Stokes Raman-scattering technique

NASA Astrophysics Data System (ADS)

Wang, Xi; Zhang, Aihua; Zhi, Miaochan; Sokolov, Alexei V.; Welch, George R.

2010-01-01

We investigate the possibility of using a hybrid coherent anti-Stokes Raman scattering technique for noninvasive monitoring of blood glucose levels. Our technique combines instantaneous coherent excitation of several characteristic molecular vibrations with subsequent probing of these vibrations by an optimally shaped, time-delayed, narrowband laser pulse. This pulse configuration mitigates the nonresonant four-wave mixing background while maximizing the Raman-resonant signal and allows rapid and highly specific detection even in the presence of multiple scattering. Under certain conditions we find that the measured signal is linearly proportional to the glucose concentration due to optical interference with the residual background light, which allows reliable detection of spectral signatures down to medically relevant glucose levels.

In Vivo Glucose Monitoring Using Dual-Wavelength Polarimetry to Overcome Corneal Birefringence in the Presence of Motion

PubMed Central

Malik, Bilal H.; Gresham, Vincent C.; Coté, Gerard L.

2012-01-01

Abstract Objective Over the past 35 years considerable research has been performed toward the investigation of noninvasive and minimally invasive glucose monitoring techniques. Optical polarimetry is one noninvasive technique that has shown promise as a means to ascertain blood glucose levels through measuring the glucose concentrations in the anterior chamber of the eye. However, one of the key limitations to the use of optical polarimetry as a means to noninvasively measure glucose levels is the presence of sample noise caused by motion-induced time-varying corneal birefringence. Research Design and Methods In this article our group presents, for the first time, results that show dual-wavelength polarimetry can be used to accurately detect glucose concentrations in the presence of motion-induced birefringence in vivo using New Zealand White rabbits. Results In total, nine animal studies (three New Zealand White rabbits across three separate days) were conducted. Using the dual-wavelength optical polarimetric approach, in vivo, an overall mean average relative difference of 4.49% (11.66 mg/dL) was achieved with 100% Zone A+B hits on a Clarke error grid, including 100% falling in Zone A. Conclusions The results indicate that dual-wavelength polarimetry can effectively be used to significantly reduce the noise due to time-varying corneal birefringence in vivo, allowing the accurate measurement of glucose concentration in the aqueous humor of the eye and correlating that with blood glucose. PMID:22691020

Effect of dietary protein on post-prandial glucose in patients with type 1 diabetes.

PubMed

Borie-Swinburne, C; Sola-Gazagnes, A; Gonfroy-Leymarie, C; Boillot, J; Boitard, C; Larger, E

2013-12-01

In flexible insulin therapy, determination of the prandial insulin dose only takes into account the carbohydrate content of the evening meal, and not the protein content. Protein can, however, contribute to gluconeogenesis. We compared the glycaemic effect of a standard evening meal with that of a test evening meal enriched in protein. The present study was conducted in 28 C-peptide negative patients with type 1 diabetes. Two evening meals that were similar in content, except that one was enriched by the addition of 300 g of 0%-fat fromage frais, were taken on two consecutive days. Insulin doses were maintained exactly the same before both evening meals. Patients were monitored with a continuous glucose-monitoring device. Patients ate similar quantities at both evening meals, except for protein (21.5 g more at the test evening meal). The preprandial insulin dose was 0.96 (0.4) U per 10 g carbohydrates. After correction for differences of interstitial glucose at the start of the evening meals, both interstitial and capillary glucose levels were similar after both evening meals, except for the late-post-prandial interstitial glucose level. We found no effect of dietary protein on post-prandial-, overnight- or late-night glucose levels in patients with type 1 diabetes. This confirms that dietary proteins need not be included in the calculation of prandial insulin dose. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

Human cervical carcinoma detection and glucose monitoring in blood micro vasculatures with swept source OCT

NASA Astrophysics Data System (ADS)

Ullah, H.; Ahmed, E.; Ikram, M.

2013-08-01

We report a pilot method, i.e., speckle variance (SV) and structured optical coherence tomography to visualize normal and malignant blood microvasculature in three and two dimensions and to monitor the glucose levels in blood by analyzing the Brownian motion of the red blood cells. The technique was applied on nude live mouse's skin and the obtained images depict the enhanced intravasculature network forum up to the depth of ˜2 mm with axial resolution of ˜8 μm. Microscopic images have also been obtained for both types of blood vessels to observe the tumor spatially. Our SV-OCT methodologies and results give satisfactory techniques in real time imaging and can potentially be applied during therapeutic techniques such as photodynamic therapy as well as to quantify the higher glucose levels injected intravenously to animal by determining the translation diffusion coefficient.

Clinical Impact of Accurate Point-of-Care Glucose Monitoring for Tight Glycemic Control in Severely Burned Children.

PubMed

Tran, Nam K; Godwin, Zachary R; Steele, Amanda N; Wolf, Steven E; Palmieri, Tina L

2016-09-01

The goal of this study was to retrospectively evaluate the clinical impact of an accurate autocorrecting blood glucose monitoring system in children with severe burns. Blood glucose monitoring system accuracy is essential for providing appropriate intensive insulin therapy and achieving tight glycemic control in critically ill patients. Unfortunately, few comparison studies have been performed to evaluate the clinical impact of accurate blood glucose monitoring system monitoring in the high-risk pediatric burn population. Retrospective analysis of an electronic health record system. Pediatric burn ICU at an academic medical center. Children (aged < 18 yr) with severe burns (≥ 20% total body surface area) receiving intensive insulin therapy guided by either a noncorrecting (blood glucose monitoring system-1) or an autocorrecting blood glucose monitoring system (blood glucose monitoring system-2). Patient demographics, insulin rates, and blood glucose monitoring system measurements were collected. The frequency of hypoglycemia and glycemic variability was compared between the two blood glucose monitoring system groups. A total of 122 patient charts from 2001 to 2014 were reviewed. Sixty-three patients received intensive insulin therapy using blood glucose monitoring system-1 and 59 via blood glucose monitoring system-2. Patient demographics were similar between the two groups. Mean insulin infusion rates (5.1 ± 3.8 U/hr; n = 535 paired measurements vs 2.4 ± 1.3 U/hr; n = 511 paired measurements; p < 0.001), glycemic variability, and frequency of hypoglycemic events (90 vs 12; p < 0.001) were significantly higher in blood glucose monitoring system-1-treated patients. Compared with laboratory measurements, blood glucose monitoring system-2 yielded the most accurate results (mean ± SD bias: -1.7 ± 6.9 mg/dL [-0.09 ± 0.4 mmol/L] vs 7.4 ± 13.5 mg/dL [0.4 ± 0.7 mmol/L]). Blood glucose monitoring system-2 patients achieve glycemic control more quickly (5.7 ± 4.3 vs 13.1 ± 6.9 hr; p< 0.001) and stayed within the target glycemic control range longer compared with blood glucose monitoring system-1 patients (85.2% ± 13.9% vs 57.9% ± 29.1%; p < 0.001). Accurate autocorrecting blood glucose monitoring system optimizes intensive insulin therapy, improves tight glycemic control, and reduces the risk of hypoglycemia and glycemic variability. The use of an autocorrecting blood glucose monitoring system for intensive insulin therapy may improve glycemic control in severely burned children.

Continuous glucose monitoring on the ICU using a subcutaneous sensor.

PubMed

Punke, M A; Decker, C; Wodack, K; Reuter, D A; Kluge, S

2015-06-01

Hypoglycemia is a frequent and feared complication of insulin therapy on the intensive care unit (ICU). Sedated patients in particular are at risk for hypoglycemia due to the absence of clinical symptoms. Furthermore, recent studies point to a correlation between the variability of blood glucose and mortality. Therefore, continuous glucose monitoring has the potential to influence outcome due to a better control of blood glucose in critically ill patients. We evaluated the efficacy, accuracy and safety of a new commercially available subcutaneous continuous glucose monitoring system (sCGM; Sentrino®, Medtronic) in a pilot study in critically ill adult patients. sCGM data were recorded for up to 72 h and values were compared with blood glucose values measured by cassette-based blood gas analyzer (BGA). A total of 14 patients (eight male, six female), with a mean age of 62.1 ± 9.8 years, referred to the ICU after major abdominal surgery were studied. The average simplified acute physiology score (SAPS II) was 35 ± 9. Three patients had known type II diabetes. The average runtime of sensors was 44.1 ± 22.1 h. In comparison to BGA, measurement of blood glucose by sCGM revealed an accuracy of 1.5 mg/dl, and a precision of +34.2 mg/dl to -31.2 mg/dl. Linn's concordance correlation coefficient yielded 0.74 with a 95% confidence interval of 0.68-0.78. No hypoglycemic events, defined as a blood glucose level below 70 mg/dl, occurred during treatment. sCGM monitoring via a subcutaneous sensor demonstrated high accuracy and considerable variability compared to blood gas samples, even in critically ill patients.

Real-time continuous glucose monitoring versus conventional glucose monitoring in critically ill patients: a systematic review study protocol.

PubMed

Zhu, Weidong; Jiang, Libing; Jiang, Shouyin; Ma, Yuefeng; Zhang, Mao

2015-01-23

Stress-induced hyperglycaemia, which has been shown to be associated with an unfavourable prognosis, is common among critically ill patients. Additionally, it has been reported that hypoglycaemia and high glucose variabilities are also associated with adverse outcomes. Thus, continuous glucose monitoring (CGM) may be the optimal method to detect severe hypoglycaemia, hyperglycaemia and decrease glucose excursion. However, the overall accuracy and reliability of CGM systems and the effects of CGM systems on glucose control and prognosis in critically ill patients remain inconclusive. Therefore, we will conduct a systematic review and meta-analysis to clarify the associations between CGM systems and clinical outcome. We will search PubMed, EMBASE and the Cochrane Library from inception to October 2014. Studies comparing CGM systems with any other glucose monitoring methods in critically ill patients will be eligible for our meta-analysis. The primary endpoints include the incidence of hypoglycaemia and hyperglycaemia, mean glucose level, and percentage of time within the target range. The second endpoints include intensive care unit (ICU) mortality, hospital mortality, duration of mechanical ventilation, length of ICU and hospital stay, and the Pearson correlation coefficient and the results of error grid analysis. In addition, we will record all complications (eg, acquired infections) in control and intervention groups and local adverse events in intervention groups (eg, bleeding or infections). Ethics approval is not required as this is a protocol for a systematic review. The findings will be disseminated in a peer-reviewed journal and presented at a relevant conference. PROSPERO registration number: CRD42014013488. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Correlation of salivary glucose level with blood glucose level in diabetes mellitus.

PubMed

Gupta, Shreya; Nayak, Meghanand T; Sunitha, J D; Dawar, Geetanshu; Sinha, Nidhi; Rallan, Neelakshi Singh

2017-01-01

Saliva is a unique fluid, which is important for normal functioning of the oral cavity. Diabetes mellitus (DM) is a disease of absolute or relative insulin deficiency characterized by insufficient secretion of insulin by pancreatic beta-cells. The diagnosis of diabetes through blood is difficult in children, older adults, debilitated and chronically ill patients, so diagnosis by analysis of saliva can be potentially valuable as collection of saliva is noninvasive, easier and technically insensitive, unlike blood. The aim of the study was to correlate blood glucose level (BGL) and salivary glucose level (SGL) in DM patients. A cross-sectional study was conducted in 120 patients, who were categorized as 40 controlled diabetics, 40 uncontrolled diabetics and 40 healthy, age- and sex-matched individuals constituted the controls. The blood and unstimulated saliva samples were collected from the patients at the different intervals for fasting, random and postprandial levels. These samples were then subjected for analysis of glucose in blood and saliva using glucose oxidase/peroxidase reagent in HITACHI 902 (R) Automatic analyzer, and the results were recorded. The mean SGLs were higher in uncontrolled and controlled diabetic groups than in nondiabetic group. A highly statistically significant correlation was found between fasting saliva glucose and fasting blood glucose in all the groups. With increase in BGL, increase in SGL was observed in patients with diabetes suggesting that SGL can be used for monitoring glycemic level in DM.

Obtaining accurate glucose measurements from wild animals under field conditions: comparing a hand held glucometer with a standard laboratory technique in grey seals

PubMed Central

Turner, Lucy M.; Millward, Sebastian; Moss, Simon E. W.; Hall, Ailsa J.

2017-01-01

Abstract Glucose is an important metabolic fuel and circulating levels are tightly regulated in most mammals, but can drop when body fuel reserves become critically low. Glucose is mobilized rapidly from liver and muscle during stress in response to increased circulating cortisol. Blood glucose levels can thus be of value in conservation as an indicator of nutritional status and may be a useful, rapid assessment marker for acute or chronic stress. However, seals show unusual glucose regulation: circulating levels are high and insulin sensitivity is limited. Accurate blood glucose measurement is therefore vital to enable meaningful health and physiological assessments in captive, wild or rehabilitated seals and to explore its utility as a marker of conservation relevance in these animals. Point-of-care devices are simple, portable, relatively cheap and use less blood compared with traditional sampling approaches, making them useful in conservation-related monitoring. We investigated the accuracy of a hand-held glucometer for ‘instant’ field measurement of blood glucose, compared with blood drawing followed by laboratory testing, in wild grey seals (Halichoerus grypus), a species used as an indicator for Good Environmental Status in European waters. The glucometer showed high precision, but low accuracy, relative to laboratory measurements, and was least accurate at extreme values. It did not provide a reliable alternative to plasma analysis. Poor correlation between methods may be due to suboptimal field conditions, greater and more variable haematocrit, faster erythrocyte settling rate and/or lipaemia in seals. Glucometers must therefore be rigorously tested before use in new species and demographic groups. Sampling, processing and glucose determination methods have major implications for conclusions regarding glucose regulation, and health assessment in seals generally, which is important in species of conservation concern and in development of circulating glucose as a marker of stress or nutritional state for use in management and monitoring. PMID:28413683

The accuracy and efficacy of real-time continuous glucose monitoring sensor in Chinese diabetes patients: a multicenter study.

PubMed

Zhou, Jian; Lv, Xiaofeng; Mu, Yiming; Wang, Xianling; Li, Jing; Zhang, Xingguang; Wu, Jinxiao; Bao, Yuqian; Jia, Weiping

2012-08-01

The purpose of this multicenter study was to investigate the accuracy of a real-time continuous glucose monitoring sensor in Chinese diabetes patients. In total, 48 patients with type 1 or 2 diabetes from three centers in China were included in the study. The MiniMed Paradigm(®) 722 insulin pump (Medtronic, Northridge, CA) was used to monitor the real-time continuous changes of blood glucose levels for three successive days. Venous blood of the subjects was randomly collected every 15 min for seven consecutive hours on the day when the subjects were wearing the sensor. Reference values were provided by the YSI(®) 2300 STAT PLUS™ glucose and lactate analyzer (YSI Life Sciences, Yellow Springs, OH). In total, 1,317 paired YSI-sensor values were collected from the 48 patients. Of the sensor readings, 88.3% (95% confidence interval, 0.84-0.92) were within±20% of the YSI values, and 95.7% were within±30% of the YSI values. Clarke and consensus error grid analyses showed that the ratios of the YSI-sensor values in Zone A to the values in Zone B were 99.1% and 99.9%, respectively. Continuous error grid analysis showed that the ratios of the YSI-sensor values in the region of accurate reading, benign errors, and erroneous reading were 96.4%, 1.8%, and 1.8%, respectively. The mean absolute relative difference (ARD) for all subjects was 10.4%, and the median ARD was 7.8%. Bland-Altman analysis detected a mean blood glucose level of 3.84 mg/dL. Trend analysis revealed that 86.1% of the difference of the rates of change between the YSI values and the sensor readings occurred within the range of 1 mg/dL/min. The Paradigm insulin pump has high accuracy in both monitoring the real-time continuous changes and predicting the trend of changes in blood glucose level. However, actual clinical manifestations should be taken into account for diagnosis of hypoglycemia.

Assessing sensor accuracy for non-adjunct use of continuous glucose monitoring.

PubMed

Kovatchev, Boris P; Patek, Stephen D; Ortiz, Edward Andrew; Breton, Marc D

2015-03-01

The level of continuous glucose monitoring (CGM) accuracy needed for insulin dosing using sensor values (i.e., the level of accuracy permitting non-adjunct CGM use) is a topic of ongoing debate. Assessment of this level in clinical experiments is virtually impossible because the magnitude of CGM errors cannot be manipulated and related prospectively to clinical outcomes. A combination of archival data (parallel CGM, insulin pump, self-monitoring of blood glucose [SMBG] records, and meals for 56 pump users with type 1 diabetes) and in silico experiments was used to "replay" real-life treatment scenarios and relate sensor error to glycemic outcomes. Nominal blood glucose (BG) traces were extracted using a mathematical model, yielding 2,082 BG segments each initiated by insulin bolus and confirmed by SMBG. These segments were replayed at seven sensor accuracy levels (mean absolute relative differences [MARDs] of 3-22%) testing six scenarios: insulin dosing using sensor values, threshold, and predictive alarms, each without or with considering CGM trend arrows. In all six scenarios, the occurrence of hypoglycemia (frequency of BG levels ≤50 mg/dL and BG levels ≤39 mg/dL) increased with sensor error, displaying an abrupt slope change at MARD =10%. Similarly, hyperglycemia (frequency of BG levels ≥250 mg/dL and BG levels ≥400 mg/dL) increased and displayed an abrupt slope change at MARD=10%. When added to insulin dosing decisions, information from CGM trend arrows, threshold, and predictive alarms resulted in improvement in average glycemia by 1.86, 8.17, and 8.88 mg/dL, respectively. Using CGM for insulin dosing decisions is feasible below a certain level of sensor error, estimated in silico at MARD=10%. In our experiments, further accuracy improvement did not contribute substantively to better glycemic outcomes.

Assessing Sensor Accuracy for Non-Adjunct Use of Continuous Glucose Monitoring

PubMed Central

Patek, Stephen D.; Ortiz, Edward Andrew; Breton, Marc D.

2015-01-01

Abstract Background: The level of continuous glucose monitoring (CGM) accuracy needed for insulin dosing using sensor values (i.e., the level of accuracy permitting non-adjunct CGM use) is a topic of ongoing debate. Assessment of this level in clinical experiments is virtually impossible because the magnitude of CGM errors cannot be manipulated and related prospectively to clinical outcomes. Materials and Methods: A combination of archival data (parallel CGM, insulin pump, self-monitoring of blood glucose [SMBG] records, and meals for 56 pump users with type 1 diabetes) and in silico experiments was used to “replay” real-life treatment scenarios and relate sensor error to glycemic outcomes. Nominal blood glucose (BG) traces were extracted using a mathematical model, yielding 2,082 BG segments each initiated by insulin bolus and confirmed by SMBG. These segments were replayed at seven sensor accuracy levels (mean absolute relative differences [MARDs] of 3–22%) testing six scenarios: insulin dosing using sensor values, threshold, and predictive alarms, each without or with considering CGM trend arrows. Results: In all six scenarios, the occurrence of hypoglycemia (frequency of BG levels ≤50 mg/dL and BG levels ≤39 mg/dL) increased with sensor error, displaying an abrupt slope change at MARD =10%. Similarly, hyperglycemia (frequency of BG levels ≥250 mg/dL and BG levels ≥400 mg/dL) increased and displayed an abrupt slope change at MARD=10%. When added to insulin dosing decisions, information from CGM trend arrows, threshold, and predictive alarms resulted in improvement in average glycemia by 1.86, 8.17, and 8.88 mg/dL, respectively. Conclusions: Using CGM for insulin dosing decisions is feasible below a certain level of sensor error, estimated in silico at MARD=10%. In our experiments, further accuracy improvement did not contribute substantively to better glycemic outcomes. PMID:25436913

Multiple functional attributes of glucose-monitoring neurons in the medial orbitofrontal (ventrolateral prefrontal) cortex.

PubMed

Szabó, István; Hormay, Edina; Csetényi, Bettina; Nagy, Bernadett; Lénárd, László; Karádi, Zoltán

2018-02-01

Multiple functional attributes of glucose-monitoring neurons in the medial orbitofrontal (ventrolateral prefrontal) cortex. NEUROSCI BIOBEHAV REV 73(1) XXX-XXX, 2017.- Special chemosensory cells, the glucose-monitoring (GM) neurons, reportedly involved in the central feeding control, exist in the medial orbitofrontal (ventrolateral prefrontal) cortex (mVLPFC). Electrophysiological, metabolic and behavioral studies reveal complex functional attributes of these cells and raise their homeostatic significance. Single neuron recordings, by means of the multibarreled microelectrophoretic technique, elucidate differential sensitivities of limbic forebrain neurons in the rat and the rhesus monkey to glucose and other chemicals, whereas gustatory stimulations demonstrate their distinct taste responsiveness. Metabolic examinations provide evidence for alteration of blood glucose level in glucose tolerance test and elevation of plasma triglyceride concentration after destruction of the local GM cells by streptozotocin (STZ). In behavioral studies, STZ microinjection into the mVLPFC fails to interfere with the acquisition of saccharin conditioned taste avoidance, does cause, however, taste perception deficit in taste reactivity tests. Multiple functional attributes of GM neurons in the mVLPFC, within the frame of the hierarchically organized central GM neuronal network, appear to play important role in the maintenance of the homeostatic balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

An investigation of spectral characteristics of water-glucose solutions

NASA Astrophysics Data System (ADS)

Lastovskaia, Elena A.; Gorbunova, Elena V.; Chertov, Aleksandr N.; Korotaev, Valery V.

2016-04-01

One of the problems of modern medical device engineering is the development of an instrument for non-invasive monitoring of glucose levels in the blood. The urgency of this task is ensured by the following facts: the increase in the incidence of diabetes, the need for regular monitoring of blood sugar, and pain of modern methods of glycemia measurement. The problem can be solved with the help of a spectrophotometric method. This report is devoted to the investigation of spectral characteristics of glucose solution with various molar concentrations. The authors proposed the methodology of experimental research and data processing algorithm. The results of the experimental studies confirmed potential opportunity of blood sugar control by spectrophotometric method. Further research is expected to continue by the way of complication of the composition of the object from an aqueous solution of glucose to biological object.

Using Continuous Glucose Monitoring Data and Detrended Fluctuation Analysis to Determine Patient Condition

PubMed Central

Thomas, Felicity; Signal, Matthew; Chase, J. Geoffrey

2015-01-01

Patients admitted to critical care often experience dysglycemia and high levels of insulin resistance, various intensive insulin therapy protocols and methods have attempted to safely normalize blood glucose (BG) levels. Continuous glucose monitoring (CGM) devices allow glycemic dynamics to be captured much more frequently (every 2-5 minutes) than traditional measures of blood glucose and have begun to be used in critical care patients and neonates to help monitor dysglycemia. In an attempt to obtain a better insight relating biomedical signals and patient status, some researchers have turned toward advanced time series analysis methods. In particular, Detrended Fluctuation Analysis (DFA) has been a topic of many recent studies in to glycemic dynamics. DFA investigates the “complexity” of a signal, how one point in time changes relative to its neighboring points, and DFA has been applied to signals like the inter-beat-interval of human heartbeat to differentiate healthy and pathological conditions. Analyzing the glucose metabolic system with such signal processing tools as DFA has been enabled by the emergence of high quality CGM devices. However, there are several inconsistencies within the published work applying DFA to CGM signals. Therefore, this article presents a review and a “how-to” tutorial of DFA, and in particular its application to CGM signals to ensure the methods used to determine complexity are used correctly and so that any relationship between complexity and patient outcome is robust. PMID:26134835

Continuous Glucose Monitoring and Trend Accuracy

PubMed Central

Gottlieb, Rebecca; Le Compte, Aaron; Chase, J. Geoffrey

2014-01-01

Continuous glucose monitoring (CGM) devices are being increasingly used to monitor glycemia in people with diabetes. One advantage with CGM is the ability to monitor the trend of sensor glucose (SG) over time. However, there are few metrics available for assessing the trend accuracy of CGM devices. The aim of this study was to develop an easy to interpret tool for assessing trend accuracy of CGM data. SG data from CGM were compared to hourly blood glucose (BG) measurements and trend accuracy was quantified using the dot product. Trend accuracy results are displayed on the Trend Compass, which depicts trend accuracy as a function of BG. A trend performance table and Trend Index (TI) metric are also proposed. The Trend Compass was tested using simulated CGM data with varying levels of error and variability, as well as real clinical CGM data. The results show that the Trend Compass is an effective tool for differentiating good trend accuracy from poor trend accuracy, independent of glycemic variability. Furthermore, the real clinical data show that the Trend Compass assesses trend accuracy independent of point bias error. Finally, the importance of assessing trend accuracy as a function of BG level is highlighted in a case example of low and falling BG data, with corresponding rising SG data. This study developed a simple to use tool for quantifying trend accuracy. The resulting trend accuracy is easily interpreted on the Trend Compass plot, and if required, performance table and TI metric. PMID:24876437

Developing strategies to enhance loading efficiency of erythrosensors

NASA Astrophysics Data System (ADS)

Bustamante Lopez, Sandra C.; Ritter, Sarah C.; Meissner, Kenith E.

2014-02-01

For diabetics, continuous glucose monitoring and the resulting tighter control of glucose levels ameliorate serious complications from hypoglycemia and hyperglycemia. Diabetics measure their blood glucose levels multiple times a day by finger pricks, or use implantable monitoring devices. Still, glucose and other analytes in the blood fluctuate throughout the day and the current monitoring methods are invasive, immunogenic, and/or present biodegradation problems. Using carrier erythrocytes loaded with a fluorescent sensor, we seek to develop a biodegradable, efficient, and potentially cost effective method to continuously sense blood analytes. We aim to reintroduce sensor-loaded erythrocytes to the bloodstream and conserve the erythrocytes lifetime of 120 days in the circulatory system. Here, we compare the efficiency of two loading techniques: hypotonic dilution and electroporation. Hypotonic dilution employs hypotonic buffer to create transient pores in the erythrocyte membrane, allowing dye entrance and a hypertonic buffer to restore tonicity. Electroporation relies on controlled electrical pulses that results in reversible pores formation to allow cargo entrance, follow by incubation at 37°C to reseal. As part of the cellular characterization of loaded erythrocytes, we focus on cell size, shape, and hemoglobin content. Cell recovery, loading efficiency and cargo release measurements render optimal loading conditions. The detected fluorescent signal from sensor-loaded erythrocytes can be translated into a direct measurement of analyte levels in the blood stream. The development of a suitable protocol to engineer carrier erythrocytes has profound and lasting implications in the erythrosensor's lifespan and sensing capabilities.

Use of an intravascular fluorescent continuous glucose sensor in subjects with type 1 diabetes mellitus.

PubMed

Romey, Matthew; Jovanovič, Lois; Bevier, Wendy; Markova, Kateryna; Strasma, Paul; Zisser, Howard

2012-11-01

Stress hyperglycemia in the critically ill is associated with increased morbidity and mortality. Continuous glucose monitoring offers a solution to the difficulties of dosing intravenous insulin properly to maintain glycemic control. The purpose of this study was to evaluate an intravascular continuous glucose monitoring (IV-CGM) system with a sensing element based on the concept of quenched fluorescence. A second-generation intravascular continuous glucose sensor was evaluated in 13 volunteer subjects with type 1 diabetes mellitus. There were 21 study sessions of up to 24 h in duration. Sensors were inserted into peripheral veins of the upper extremity, up to two sensors per subject per study session. Sensor output was compared with temporally correlated reference measurements obtained from venous samples on a laboratory glucose analyzer. Data were obtained from 23 sensors in 13 study sessions with 942 paired reference values. Fourteen out of 23 sensors (60.9%) had a mean absolute relative difference ≤ 10%. Eighty-nine percent of paired points were in the clinically accurate A zone of the Clarke error grid and met ISO 15197 performance criteria. Adequate venous blood flow was identified as a necessary condition for accuracy when local sensor readings are compared with venous blood glucose. The IV-CGM system was capable of achieving a high level of glucose measurement accuracy. However, superficial peripheral veins may not provide adequate blood flow for reliable indwelling blood glucose monitoring. © 2012 Diabetes Technology Society.

Use of an Intravascular Fluorescent Continuous Glucose Sensor in Subjects with Type 1 Diabetes Mellitus

PubMed Central

Romey, Matthew; Jovanovič, Lois; Bevier, Wendy; Markova, Kateryna; Strasma, Paul; Zisser, Howard

2012-01-01

Background Stress hyperglycemia in the critically ill is associated with increased morbidity and mortality. Continuous glucose monitoring offers a solution to the difficulties of dosing intravenous insulin properly to maintain glycemic control. The purpose of this study was to evaluate an intravascular continuous glucose monitoring (IV-CGM) system with a sensing element based on the concept of quenched fluorescence. Method A second-generation intravascular continuous glucose sensor was evaluated in 13 volunteer subjects with type 1 diabetes mellitus. There were 21 study sessions of up to 24 h in duration. Sensors were inserted into peripheral veins of the upper extremity, up to two sensors per subject per study session. Sensor output was compared with temporally correlated reference measurements obtained from venous samples on a laboratory glucose analyzer. Results Data were obtained from 23 sensors in 13 study sessions with 942 paired reference values. Fourteen out of 23 sensors (60.9%) had a mean absolute relative difference ≤ 10%. Eighty-nine percent of paired points were in the clinically accurate A zone of the Clarke error grid and met ISO 15197 performance criteria. Adequate venous blood flow was identified as a necessary condition for accuracy when local sensor readings are compared with venous blood glucose. Conclusions The IV-CGM system was capable of achieving a high level of glucose measurement accuracy. However, superficial peripheral veins may not provide adequate blood flow for reliable indwelling blood glucose monitoring. PMID:23294770

Glucose Prediction Algorithms from Continuous Monitoring Data: Assessment of Accuracy via Continuous Glucose Error-Grid Analysis.

PubMed

Zanderigo, Francesca; Sparacino, Giovanni; Kovatchev, Boris; Cobelli, Claudio

2007-09-01

The aim of this article was to use continuous glucose error-grid analysis (CG-EGA) to assess the accuracy of two time-series modeling methodologies recently developed to predict glucose levels ahead of time using continuous glucose monitoring (CGM) data. We considered subcutaneous time series of glucose concentration monitored every 3 minutes for 48 hours by the minimally invasive CGM sensor Glucoday® (Menarini Diagnostics, Florence, Italy) in 28 type 1 diabetic volunteers. Two prediction algorithms, based on first-order polynomial and autoregressive (AR) models, respectively, were considered with prediction horizons of 30 and 45 minutes and forgetting factors (ff) of 0.2, 0.5, and 0.8. CG-EGA was used on the predicted profiles to assess their point and dynamic accuracies using original CGM profiles as reference. Continuous glucose error-grid analysis showed that the accuracy of both prediction algorithms is overall very good and that their performance is similar from a clinical point of view. However, the AR model seems preferable for hypoglycemia prevention. CG-EGA also suggests that, irrespective of the time-series model, the use of ff = 0.8 yields the highest accurate readings in all glucose ranges. For the first time, CG-EGA is proposed as a tool to assess clinically relevant performance of a prediction method separately at hypoglycemia, euglycemia, and hyperglycemia. In particular, we have shown that CG-EGA can be helpful in comparing different prediction algorithms, as well as in optimizing their parameters.

Recent Advances in Nanotechnology for Diabetes Treatment

PubMed Central

DiSanto, Rocco Michael; Subramanian, Vinayak; Gu, Zhen

2015-01-01

Nanotechnology in diabetes research has facilitated the development of novel glucose measurement and insulin delivery modalities which hold the potential to dramatically improve quality of life for diabetics. Recent progress in the field of diabetes research at its interface with nanotechnology is our focus. In particular, we examine glucose sensors with nanoscale components including metal nanoparticles and carbon nanostructures. The addition of nanoscale components commonly increases glucose sensor sensitivity, temporal response, and can lead to sensors which facilitate continuous in vivo glucose monitoring. Additionally, we survey nanoscale approaches to “closed-loop” insulin delivery strategies which automatically release insulin in response to fluctuating blood glucose levels. “Closing the loop” between blood glucose level (BGL) measurements and insulin administration by removing the requirement of patient action holds the potential to dramatically improve the health and quality of life of diabetics. Advantages and limitations of current strategies, as well as future opportunities and challenges are also discussed. PMID:25641955

Proposed Application of Fast Fourier Transform in Near Infra Red Based Non Invasive Blood Glucose Monitoring System

NASA Astrophysics Data System (ADS)

Jenie, R. P.; Iskandar, J.; Kurniawan, A.; Rustami, E.; Syafutra, H.; Nurdin, N. M.; Handoyo, T.; Prabowo, J.; Febryarto, R.; Rahayu, M. S. K.; Damayanthi, E.; Rimbawan; Sukandar, D.; Suryana, Y.; Irzaman; Alatas, H.

2017-03-01

Worldwide emergence of glycaemic status related health disorders, such as diabetes and metabolic syndrome, is growing in alarming rate. The objective was to propose new methods for non invasive blood glucose level measurement system, based on implementation of Fast Fourier Transform methods. This was an initial-lab-scale-research. Data on non invasive blood glucose measurement are referred from Scopus, Medline, and Google Scholar, from 2011 until 2016, and was used as design references, combined with in house verification. System was developed in modular fashion, based on aforementioned compiled references. Several preliminary tests to understand relationship between LED and photo-diode responses have been done. Several references were used as non invasive blood glucose measurement tools design basis. Solution is developed in modular fashion. we have proven different sensor responses to water and glucose. Human test for non invasive blood glucose level measurement system is needed.

Utility of different glycemic control metrics for optimizing management of diabetes.

PubMed

Kohnert, Klaus-Dieter; Heinke, Peter; Vogt, Lutz; Salzsieder, Eckhard

2015-02-15

The benchmark for assessing quality of long-term glycemic control and adjustment of therapy is currently glycated hemoglobin (HbA1c). Despite its importance as an indicator for the development of diabetic complications, recent studies have revealed that this metric has some limitations; it conveys a rather complex message, which has to be taken into consideration for diabetes screening and treatment. On the basis of recent clinical trials, the relationship between HbA1c and cardiovascular outcomes in long-standing diabetes has been called into question. It becomes obvious that other surrogate and biomarkers are needed to better predict cardiovascular diabetes complications and assess efficiency of therapy. Glycated albumin, fructosamin, and 1,5-anhydroglucitol have received growing interest as alternative markers of glycemic control. In addition to measures of hyperglycemia, advanced glucose monitoring methods became available. An indispensible adjunct to HbA1c in routine diabetes care is self-monitoring of blood glucose. This monitoring method is now widely used, as it provides immediate feedback to patients on short-term changes, involving fasting, preprandial, and postprandial glucose levels. Beyond the traditional metrics, glycemic variability has been identified as a predictor of hypoglycemia, and it might also be implicated in the pathogenesis of vascular diabetes complications. Assessment of glycemic variability is thus important, but exact quantification requires frequently sampled glucose measurements. In order to optimize diabetes treatment, there is a need for both key metrics of glycemic control on a day-to-day basis and for more advanced, user-friendly monitoring methods. In addition to traditional discontinuous glucose testing, continuous glucose sensing has become a useful tool to reveal insufficient glycemic management. This new technology is particularly effective in patients with complicated diabetes and provides the opportunity to characterize glucose dynamics. Several continuous glucose monitoring (CGM) systems, which have shown usefulness in clinical practice, are presently on the market. They can broadly be divided into systems providing retrospective or real-time information on glucose patterns. The widespread clinical application of CGM is still hampered by the lack of generally accepted measures for assessment of glucose profiles and standardized reporting of glucose data. In this article, we will discuss advantages and limitations of various metrics for glycemic control as well as possibilities for evaluation of glucose data with the special focus on glycemic variability and application of CGM to improve individual diabetes management.

Screening, monitoring, and educating patients with diabetes in an independent community pharmacy in Puerto Rico.

PubMed

Jiménez, F J; Monsanto, H A

2001-03-01

Increase the awareness about the importance of Diabetes mellitus (DM) management and assess the educational and monitoring needs of patients visiting a community pharmacy in Puerto Rico. A community service activity focusing on DM was held in a community pharmacy. The educational and monitoring needs of the participants were assessed using a questionnaire. Glucose tests were conducted in the pharmacy by medical technologists. Educational activities consisted of presentations and printed materials. Two-thirds of the fasting people had blood glucose levels higher than 140 mg/dl. Seventy-nine percent of the patients with diabetes were not aware of the glycosilated hemoglobin test. Most of the patients were interested in learning more about how to manage their condition. A greater understanding is needed among patients with DM that blood glucose control decreases diabetes related complications. Community pharmacists are in an excellent position to collaborate with other health professionals in screening, monitoring and educating patients with DM to prevent long-term complications.

Sensing glucose concentrations at GHz frequencies with a fully embedded Biomicro-electromechanical system (BioMEMS)

NASA Astrophysics Data System (ADS)

Birkholz, M.; Ehwald, K.-E.; Basmer, T.; Kulse, P.; Reich, C.; Drews, J.; Genschow, D.; Haak, U.; Marschmeyer, S.; Matthus, E.; Schulz, K.; Wolansky, D.; Winkler, W.; Guschauski, T.; Ehwald, R.

2013-06-01

The progressive scaling in semiconductor technology allows for advanced miniaturization of intelligent systems like implantable biosensors for low-molecular weight analytes. A most relevant application would be the monitoring of glucose in diabetic patients, since no commercial solution is available yet for the continuous and drift-free monitoring of blood sugar levels. We report on a biosensor chip that operates via the binding competition of glucose and dextran to concanavalin A. The sensor is prepared as a fully embedded micro-electromechanical system and operates at GHz frequencies. Glucose concentrations derive from the assay viscosity as determined by the deflection of a 50 nm TiN actuator beam excited by quasi-electrostatic attraction. The GHz detection scheme does not rely on the resonant oscillation of the actuator and safely operates in fluidic environments. This property favorably combines with additional characteristics—(i) measurement times of less than a second, (ii) usage of biocompatible TiN for bio-milieu exposed parts, and (iii) small volume of less than 1 mm3—to qualify the sensor chip as key component in a continuous glucose monitor for the interstitial tissue.

Treatment with continuous positive airway pressure may affect blood glucose levels in nondiabetic patients with obstructive sleep apnea syndrome.

PubMed

Czupryniak, Leszek; Loba, Jerzy; Pawlowski, Maciej; Nowak, Dariusz; Bialasiewicz, Piotr

2005-05-01

Obstructive sleep apnea syndrome (OSAS) is often associated with impaired glucose metabolism. Data on the effects of OSAS treatment with continuous positive airway pressure (CPAP) on blood glucose and insulin resistance are conflicting. The study aimed at assessing the immediate effect of CPAP on glucose control measured with a continuous glucose monitoring system (CGMS). Nine non-diabetes subjects with OSAS (mean age 53.0 +/- 8.0 years; body mass index 34.8 +/- 5.3 kg/m2) underwent 2 overnight polysomnographic examinations: a diagnostic study and one with CPAP treatment. Continuous glucose monitoring system (CGMS) was applied overnight on both occasions. Glucose metabolism was assessed with a 75-g oral glucose tolerance test, plasma insulin and homeostatic model assessment of insulin resistance (HOMA-IR) index. The mean (+/- SD) apnoea-hypopnea index (AHI) at diagnostic polysomnography was 54.3 +/- 29.3 (range 16-81). Fasting plasma insulin levels in patients with OSAS was 84.3 +/- 43.4 pM at baseline, and the HOMA-IR was 3.6 +/- 2.2. CPAP treatment in the subjects with OSAS resulted in a significant reduction in the AHI to 4.5 +/- 7.1. All of the major saturation parameters improved significantly on CPAP. CGMS showed mean glucose values significantly higher during the CPAP night than during the diagnostic night: 80 +/- 11 mg/dL versus 63 +/- 7 mg/dL (P < .01). Fasting insulin and HOMA-IR measured after the CPAP night tended to be higher than at baseline (98.4 +/- 51.0 pmol vs 84.3 +/- 43.4 pmol and 3.9 pmol +/- 2.6 vs 3.6 +/- 2.2 pmol, respectively, P > .05). CPAP treatment in nondiabetic obese patients with OSAS may have an immediate elevating effect on blood glucose.

Flexible three-dimensional electrochemical glucose sensor with improved sensitivity realized in hybrid polymer microelectromechanical systems technique.

PubMed

Patel, Jasbir N; Gray, Bonnie L; Kaminska, Bozena; Gates, Byron D

2011-09-01

Continuous glucose monitoring for patients with diabetes is of paramount importance to avoid severe health conditions resulting from hypoglycemia or hyperglycemia. Most available methods require an invasive setup and a health care professional. Handheld devices available on the market also require finger pricking for every measurement and do not provide continuous monitoring. Hence, continuous glucose monitoring from human tears using a glucose sensor embedded in a contact lens has been considered as a suitable option. However, the glucose concentration in human tears is very low in comparison with the blood glucose level (1/10-1/40 concentration). We propose a sensor that solves the sensitivity problem in a new way, is flexible, and is constructed onto the oxygen permeable contact lens material. To achieve such sensitivity while maintaining a small sensor footprint suitable for placement in a contact lens, we increased the active electrode area by using three-dimensional (3-D) electrode micropatterning. Fully flexible 3-D electrodes were realized utilizing ordered arrays of pillars with different shapes and heights. We successfully fabricated square and cylindrical pillars with different height (50, 100, and 200 μm) and uniform metal coverage to realize sensor electrodes. The increased surface area produces high amperometric current that increases sensor sensitivity up to 300% using 200 μm tall square pillars. The sensitivity improvement closely follows the improvement in the surface area of the electrode. The proposed flexible glucose sensors with 3-D microstructure electrodes are more sensitive to lower glucose concentrations and generate higher current signal than conventional glucose sensors. © 2011 Diabetes Technology Society.

A fine pointed glucose oxidase immobilized electrode for low-invasive amperometric glucose monitoring.

PubMed

Li, Jiang; Koinkar, Pankaj; Fuchiwaki, Yusuke; Yasuzawa, Mikito

2016-12-15

A low invasive type glucose sensor, which has a sensing region at the tip of a fine pointed electrode, was developed for continuous glucose monitoring. Platinum-iridium alloy electrode with a surface area of 0.045mm(2) was settled at the middle of pointed PEEK (Polyetheretherketone) tubing and was employed as sensing electrode. Electrodeposition of glucose oxidase in the presence of surfactant, Triton X-100, was performed for high-density enzyme immobilization followed by the electropolymerization of o-phenylenediamine for the formation of functional entrapping and permselective polymer membrane. Ag/AgCl film was coated on the surface of PEEK tubing as reference electrode. Amperometric responses of the prepared sensors to glucose were measured at a potential of 0.60V (vs. Ag/AgCl). The prepared electrode showed the sensitivity of 2.55μA/cm(2) mM with high linearity of 0.9986, within the glucose concentration range up to 21mM. The detection limit (S/N=3) was determined to be 0.11mM. The glucose sensor properties were evaluated in phosphate buffer solution and in vivo monitoring by the implantation of the sensors in rabbit, while conventional needle type sensors as a reference were used. The results showed that change in output current of the proposed sensor fluctuated similar with one in output current of the conventional needle type sensors, which was also in similar accordance with actual blood sugar level measured by commercially glucose meter. One-point calibration method was used to calibrate the sensor output current. Copyright © 2016 Elsevier B.V. All rights reserved.

Analytical performance of glucose monitoring systems at different blood glucose ranges and analysis of outliers in a clinical setting.

PubMed

Hasslacher, Christoph; Kulozik, Felix; Platten, Isabel

2014-05-01

We investigated the analytical accuracy of 27 glucose monitoring systems (GMS) in a clinical setting, using the new ISO accuracy limits. In addition to measuring accuracy at blood glucose (BG) levels < 100 mg/dl and > 100 mg/dl, we also analyzed devices performance with respect to these criteria at 5 specific BG level ranges, making it possible to further differentiate between devices with regard to overall performance. Carbohydrate meals and insulin injections were used to induce an increase or decrease in BG levels in 37 insulin-dependent patients. Capillary blood samples were collected at 10-minute intervals, and BG levels determined simultaneously using GMS and a laboratory-based method. Results obtained via both methods were analyzed according to the new ISO criteria. Only 12 of 27 devices tested met overall requirements of the new ISO accuracy limits. When accuracy was assessed at BG levels < 100 mg/dl and > 100 mg/dl, criteria were met by 14 and 13 devices, respectively. A more detailed analysis involving 5 different BG level ranges revealed that 13 (48.1%) devices met the required criteria at BG levels between 50 and 150 mg/dl, whereas 19 (70.3%) met these criteria at BG levels above 250 mg/dl. The overall frequency of outliers was low. The assessment of analytical accuracy of GMS at a number of BG level ranges made it possible to further differentiate between devices with regard to overall performance, a process that is of particular importance given the user-centered nature of the devices' intended use. © 2014 Diabetes Technology Society.

Microminiature Monitor for Vital Electrolyte and Metabolite Levels of Astronauts

NASA Technical Reports Server (NTRS)

Tohda, Koji; Gratzl, Miklos

2004-01-01

Ions, such as proton (pH) and potassium, play a crucial role in body fluids to maintain proper basic functioning of cells and tissues. Metabolites, such as glucose, control the energy available to the entire human body in normal as well as stress situations, and before, during, and after meals. These molecules diffuse easily between blood in the capillaries and the interstitial fluid residing between cells and tissues. We have developed and approach to monitoring of critical ions (called electrolytes) and glucose in the interstitial fluid under the human skin. Proton and potassium levels sensed using optode technology that translates the respective ionic concentrations into variable colors of corresponding ionophore/dye/polymeric liquid membranes. Glucose is monitored indirectly, by coupling through immobilized glucose oxidase with local pH that is then detected using a similar color scheme. The monitor consists of a tiny plastic bar, 100-200 microns wide and 1-2 mm long, placed just under the skin, with color changing spots for each analyte as well as blanks. The colors are read and translated into concentration values by a CCD camera. Direct optical coupling between the in vivo sensing bar and the ex vivo detector device requires no power, and thus eliminates the need for wires or optical fibers crossing the skin. The microminiature bar penetrates the skin easily and painlessly, so that astronauts could insert it themselves. The approach is fully compatible with telemetry in space, and thus, in vivo clinical data will be available real time in the Earth based command center once the device is fully developed. The information provided can be used for collecting hitherto unavailable vital data on clinical effects of space travel. Managing clinical emergencies in space with the sensor already in place should also become much more efficient than without a continuous monitor, as is currently the case. Civilian applications may include better glucose control of patients with moderate to severe diabetes: a growing health problem in the US and World-wide.

Assessment of Knowledge of Self Blood Glucose Monitoring and Extent of Self Titration of Anti-Diabetic Drugs among Diabetes Mellitus Patients - A Cross Sectional, Community Based Study.

PubMed

Krishnan, V; Thirunavukkarasu, J

2016-03-01

Self blood glucose monitoring is an important context of self care in the management of diabetes mellitus. All the guidelines must be followed while performing self blood glucose monitoring and tracking of values is essential to facilitate the physician while titrating the drugs and /or doses of anti diabetes medication. Self titration by patients following self monitoring must be discouraged. To assess the knowledge and practice of self blood glucose monitoring among diabetes patients and extent of self titration of anti diabetes medicines among diabetes patients based on self blood glucose monitoring. This pilot, cross-sectional, observational study was conducted using a validated questionnaire among adult male and female diabetes patients performing self blood glucose monitoring at home. Diabetes patients with complications and juvenile diabetes patients were excluded. Out of 153 patients surveyed, only 37 (24.1%) (20 males, 17 females) patients were aware and have been following self blood glucose monitoring appropriately. About 116 (75.8%) (64 males, 52 females) of patients were devoid of adequate knowledge and did not practice self blood glucose monitoring in a proper way. Ninety eight (64.05%) accepted that they self titrate their anti diabetic medicines based on self monitoring. Self monitoring of blood glucose should be encouraged and patients should be taught importance of following correct steps and tracking of self monitoring by physician or diabetes educator.

Toward CMOS image sensor based glucose monitoring.

PubMed

Devadhasan, Jasmine Pramila; Kim, Sanghyo

2012-09-07

Complementary metal oxide semiconductor (CMOS) image sensor is a powerful tool for biosensing applications. In this present study, CMOS image sensor has been exploited for detecting glucose levels by simple photon count variation with high sensitivity. Various concentrations of glucose (100 mg dL(-1) to 1000 mg dL(-1)) were added onto a simple poly-dimethylsiloxane (PDMS) chip and the oxidation of glucose was catalyzed with the aid of an enzymatic reaction. Oxidized glucose produces a brown color with the help of chromogen during enzymatic reaction and the color density varies with the glucose concentration. Photons pass through the PDMS chip with varying color density and hit the sensor surface. Photon count was recognized by CMOS image sensor depending on the color density with respect to the glucose concentration and it was converted into digital form. By correlating the obtained digital results with glucose concentration it is possible to measure a wide range of blood glucose levels with great linearity based on CMOS image sensor and therefore this technique will promote a convenient point-of-care diagnosis.

New Insights into Cytosolic Glucose Levels during Differentiation of 3T3-L1 Fibroblasts into Adipocytes*

PubMed Central

Kovacic, Petra Brina; Chowdhury, Helena H.; Velebit, Jelena; Kreft, Marko; Jensen, Jørgen; Zorec, Robert

2011-01-01

Cytosolic glucose concentration reflects the balance between glucose entry across the plasma membrane and cytosolic glucose utilization. In adipocytes, glucose utilization is considered very rapid, meaning that every glucose molecule entering the cytoplasm is quickly phosphorylated. Thus, the cytosolic free glucose concentration is considered to be negligible; however, it was never measured directly. In the present study, we monitored cytosolic glucose dynamics in 3T3-L1 fibroblasts and adipocytes by expressing a fluorescence resonance energy transfer (FRET)-based glucose nanosensor: fluorescent indicator protein FLIPglu-600μ. Specifically, we monitored cytosolic glucose responses by varying transmembrane glucose concentration gradient. The changes in cytosolic glucose concentration were detected in only 56% of 3T3-L1 fibroblasts and in 14% of 3T3-L1 adipocytes. In adipocytes, the resting cytosolic glucose concentration was reduced in comparison with the one recorded in fibroblasts. Membrane permeabilization increased cytosolic glucose concentration in adipocytes, and glycolytic inhibitor iodoacetate failed to increase cytosolic glucose concentration, indicating low adipocyte permeability for glucose at rest. We also examined the effects of insulin and adrenaline. Insulin significantly increased cytosolic glucose concentration in adipocytes by a factor of 3.6; however, we recorded no effect on delta ratio (ΔR) in fibroblasts. Adrenaline increased cytosolic glucose concentration in fibroblasts but not in adipocytes. However, in adipocytes in insulin-stimulated conditions, glucose clearance was significantly faster following adrenaline addition in comparison with controls (p < 0.001). Together, these results demonstrate that during differentiation, adipocytes develop more efficient mechanisms for maintaining low cytosolic glucose concentration, predominantly with reduced membrane permeability for glucose. PMID:21349852

First Clinical Experience with Retrospective Flash Glucose Monitoring (FGM) Analysis in South Africa: Characterizing Glycemic Control with Ambulatory Glucose Profile.

PubMed

Distiller, Larry A; Cranston, Iain; Mazze, Roger

2016-11-01

In 2014, an innovative blinded continuous glucose monitoring system was introduced with automated ambulatory glucose profile (AGP) reporting. The clinical use and interpretation of this new technology has not previously been described. Therefore we wanted to understand its use in characterizing key factors related to glycemic control: glucose exposure, variability, and stability, and risk of hypoglycemia in clinical practice. Clinicians representing affiliated diabetes centers throughout South Africa were trained and subsequently were given flash glucose monitoring readers and 2-week glucose sensors to use at their discretion. After patient use, sensor data were collected and uploaded for AGP reporting. Complete data (sensor AGP with corresponding clinical information) were obtained for 50 patients with type 1 (70%) and type 2 diabetes (30%), irrespective of therapy. Aggregated analysis of AGP data comparing patients with type 1 versus type 2 diabetes, revealed that despite similar HbA1c values between both groups (8.4 ± 2 vs 8.6 ± 1.7%, respectively), those with type 2 diabetes had lower mean glucose levels (9.2 ± 3 vs 10.3 mmol/l [166 ± 54 vs 185 mg/dl]) and lower indices of glucose variability (3.0 ± 1.5 vs 5.0 ± 1.9 mmol/l [54 ± 27 vs 90 ± 34.2 mg/dl]). This highlights key areas for future focus. Using AGP, the characteristics of glucose exposure, variability, stability, and hypoglycemia risk and occurrence were obtained within a short time and with minimal provider and patient input. In a survey at the time of the follow-up visit, clinicians indicated that aggregated AGP data analysis provided important new clinical information and insights. © 2016 Diabetes Technology Society.

Professional continuous glucose monitoring for the identification of type 1 diabetes mellitus among subjects with insulin therapy.

PubMed

Chen, Yin-Chun; Huang, Yu-Yao; Li, Hung-Yuan; Liu, Shih-Wei; Hsieh, Sheng-Hwu; Lin, Chia-Hung

2015-01-01

The identification of type 1 diabetes in diabetic subjects receiving insulin therapy is sometimes difficult. The purpose of this study is to evaluate whether results of professional continuous glucose monitoring can improve the identification of type 1 diabetes.From 2007 to 2012, 119 adults receiving at least twice-daily insulin therapy and professional continuous glucose monitoring were recruited. Type 1 diabetes was diagnosed by endocrinologists according to American Diabetes Association standards, including a very low C-peptide level (<0.35  pg/mL) or the presence of diabetic ketoacidosis. Continuous glucose monitoring was applied for 3 days.Among 119 subjects, 86 were diagnosed with type 1 diabetes. Subjects with type 1 diabetes were younger (33.8 vs 52.3 years old, P < 0.001), had lower body mass index (BMI, 21.95 vs 24.42, P = 0.003), lower serum creatinine (61.77  vs 84.65 μmol/L, P = 0.001), and higher estimated glomerular filtration rate (108.71 vs 76.48 mg/mL/min/1.73m2, P < 0.001) than subjects with type 2 diabetes. Predictive scores for identification of type 1 diabetes were constructed, including age, BMI, average mean amplitude of glucose excursion in days 2 and 3, and the area under the curve of nocturnal hyperglycemic and hypoglycemic states. The area under the receiver operating characteristic curve was 0.90. With the cutoff of 0.58, the sensitivity was 86.7% and the specificity was 80.8%. The good performance was validated by the leave-one-out method (sensitivity 83.3%, specificity 73.1%).Professional continuous glucose monitoring is a useful tool that improves identification of type 1 diabetes among diabetic patients receiving insulin therapy.

Metabolic regulation during constant moderate physical exertion in extreme conditions in Type 1 diabetes.

PubMed

Valletta, J J; Chipperfield, A J; Clough, G F; Byrne, C D

2012-06-01

Constant moderate intensity physical exertion in humid environments at altitude poses a considerable challenge to maintaining euglycaemia with Type 1 diabetes. Blood glucose concentrations and energy expenditure were continuously recorded in a person trekking at altitude in a tropical climate to quantify changes in glucose concentrations in relation to energy expenditure. Blood glucose concentrations and energy expenditure were continuously monitored with a Guardian® real-time continuous glucose monitoring system (CGMS) and a SenseWear® Pro3 armband (BodyMedia Inc., USA), in a 27-year-old woman with Type 1 diabetes, during her climb up Mount Kinabalu in Borneo (c. 4095 m). Comparative control data from the same person was collected in the UK (temperate climate at sea level) and Singapore (tropical climate at sea level). Maximum physical effort during the climb was < 60% VO(2MAX) (maximal oxygen consumption). Mean daily calorific intakes were 2300 kcal (UK), 2370 kcal (Singapore) and 2274 kcal (Mount Kinabalu), and mean daily insulin doses were 54 U (UK), 40 U (Singapore) and 47 U (Mount Kinabalu). Despite markedly increased energy expenditure during the climb [4202 kcal (Mount Kinabalu) vs. 2948 kcal (UK) and 2662 kcal (Singapore)], mean blood glucose was considerably higher during the trek up Mount Kinabalu [13.2 ± 5.9 mmol/l, vs. 7.9 ± 3.8 mmol/l (UK) and 8.6 ± 4.0 mmol/l (Singapore)]. Marked unexpected hyperglycaemia occurred while trekking on Mount Kinabalu, despite similar calorie consumption and insulin doses to control conditions. Because of the risk of unexpected hyperglycaemia in these conditions, we recommend that patients embarking on similar activity holidays undertake frequent blood glucose monitoring. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

Lasting monitoring of immune state in patients with coronary atherosclerosis

NASA Astrophysics Data System (ADS)

Malinova, Lidia I.; Denisova, Tatyana P.; Tuchin, Valery V.

2007-02-01

Immune state monitoring is an expensive, invasive and sometimes difficult necessity in patients with different disorders. Immune reaction dynamics study in patients with coronary atherosclerosis provides one of the leading components to complication development, clinical course prognosis and treatment and rehabilitation tactics. We've chosen intravenous glucose injection as metabolic irritant in the following four groups of patients: men with proved coronary atherosclerosis (CA), non insulin dependent diabetes mellitus (NIDDM), men hereditary burden by CA and NIDDM and practically healthy persons with longlivers in generation. Immune state parameters such as quantity of leukocytes and lymphocytes, circulating immune complexes levels, serum immunoglobulin levels, HLA antigen markers were studied at 0, 30 and 60 minutes during glucose loading. To obtain continues time function of studied parameters received data were approximated by polynomials of high degree with after going first derivatives. Time functions analyze elucidate principally different dynamics studied parameters in all chosen groups of patients, which couldn't be obtained from discontinuous data compare. Leukocyte and lymphocyte levels dynamics correlated HLA antigen markers in all studied groups. Analytical estimation of immune state in patients with coronary atherosclerosis shows the functional "margin of safety" of immune system state under glucose disturbance. Proposed method of analytical estimation also can be used in immune system monitoring in other groups of patients.

Metformin improves glucose effectiveness, not insulin sensitivity: predicting treatment response in women with polycystic ovary syndrome in an open-label, interventional study.

PubMed

Pau, Cindy T; Keefe, Candace; Duran, Jessica; Welt, Corrine K

2014-05-01

Although metformin is widely used to improve insulin resistance in women with polycystic ovary syndrome (PCOS), its mechanism of action is complex, with inconsistent effects on insulin sensitivity and variability in treatment response. The aim of the study was to delineate the effect of metformin on glucose and insulin parameters, determine additional treatment outcomes, and predict patients with PCOS who will respond to treatment. We conducted an open-label, interventional study at an academic medical center. Women with PCOS (n = 36) diagnosed by the National Institutes of Health criteria participated in the study. Subjects underwent fasting blood sampling, an IV glucose tolerance test, dual-energy x-ray absorptiometry scan, transvaginal ultrasound, and measurement of human chorionic gonadotropin-stimulated androgen levels before and after 12 weeks of treatment with metformin extended release 1500 mg/d. Interval visits were performed to monitor anthropometric measurements and menstrual cycle parameters. Changes in glucose and insulin parameters, androgen levels, anthropometric measurements, and ovulatory menstrual cycles were evaluated. Insulin sensitivity did not change despite weight loss. Glucose effectiveness (P = .002) and the acute insulin response to glucose (P = .002) increased, and basal glucose levels (P = .001) decreased after metformin treatment. T levels also decreased. Women with improved ovulatory function (61%) had lower baseline T levels and lower baseline and stimulated T and androstenedione levels after metformin treatment (all P < .05). Using an IV glucose tolerance test, which distinguishes improvements in glucose effectiveness and insulin sensitivity, metformin does not improve insulin sensitivity in women with PCOS but does improve glucose effectiveness. The improvement in glucose effectiveness may be partially mediated by decreased glucose levels. T levels also decreased with metformin treatment. Ovulation during metformin treatment was associated with lower baseline T levels and greater T and androstenedione decreases during treatment, but not with insulin or LH levels. Thus, the action of metformin in PCOS primarily affects glucose levels and steroidogenesis, which may be mediated by mechanisms that affect both pathways, such as inhibition of mitochondrial complex I.

Metformin Improves Glucose Effectiveness, Not Insulin Sensitivity: Predicting Treatment Response in Women With Polycystic Ovary Syndrome in an Open-Label, Interventional Study

PubMed Central

Pau, Cindy T.; Keefe, Candace; Duran, Jessica

2014-01-01

Context: Although metformin is widely used to improve insulin resistance in women with polycystic ovary syndrome (PCOS), its mechanism of action is complex, with inconsistent effects on insulin sensitivity and variability in treatment response. Objective: The aim of the study was to delineate the effect of metformin on glucose and insulin parameters, determine additional treatment outcomes, and predict patients with PCOS who will respond to treatment. Design and Setting: We conducted an open-label, interventional study at an academic medical center. Subjects: Women with PCOS (n = 36) diagnosed by the National Institutes of Health criteria participated in the study. Interventions: Subjects underwent fasting blood sampling, an IV glucose tolerance test, dual-energy x-ray absorptiometry scan, transvaginal ultrasound, and measurement of human chorionic gonadotropin-stimulated androgen levels before and after 12 weeks of treatment with metformin extended release 1500 mg/d. Interval visits were performed to monitor anthropometric measurements and menstrual cycle parameters. Main Outcome Measures: Changes in glucose and insulin parameters, androgen levels, anthropometric measurements, and ovulatory menstrual cycles were evaluated. Results: Insulin sensitivity did not change despite weight loss. Glucose effectiveness (P = .002) and the acute insulin response to glucose (P = .002) increased, and basal glucose levels (P = .001) decreased after metformin treatment. T levels also decreased. Women with improved ovulatory function (61%) had lower baseline T levels and lower baseline and stimulated T and androstenedione levels after metformin treatment (all P < .05). Conclusions: Using an IV glucose tolerance test, which distinguishes improvements in glucose effectiveness and insulin sensitivity, metformin does not improve insulin sensitivity in women with PCOS but does improve glucose effectiveness. The improvement in glucose effectiveness may be partially mediated by decreased glucose levels. T levels also decreased with metformin treatment. Ovulation during metformin treatment was associated with lower baseline T levels and greater T and androstenedione decreases during treatment, but not with insulin or LH levels. Thus, the action of metformin in PCOS primarily affects glucose levels and steroidogenesis, which may be mediated by mechanisms that affect both pathways, such as inhibition of mitochondrial complex I. PMID:24606093

An Implantable RFID Sensor Tag toward Continuous Glucose Monitoring.

PubMed

Xiao, Zhibin; Tan, Xi; Chen, Xianliang; Chen, Sizheng; Zhang, Zijian; Zhang, Hualei; Wang, Junyu; Huang, Yue; Zhang, Peng; Zheng, Lirong; Min, Hao

2015-05-01

This paper presents a wirelessly powered implantable electrochemical sensor tag for continuous blood glucose monitoring. The system is remotely powered by a 13.56-MHz inductive link and utilizes an ISO 15693 radio frequency identification (RFID) standard for communication. This paper provides reliable and accurate measurement for changing glucose level. The sensor tag employs a long-term glucose sensor, a winding ferrite antenna, an RFID front-end, a potentiostat, a 10-bit sigma-delta analog to digital converter, an on-chip temperature sensor, and a digital baseband for protocol processing and control. A high-frequency external reader is used to power, command, and configure the sensor tag. The only off-chip support circuitry required is a tuned antenna and a glucose microsensor. The integrated chip fabricated in SMIC 0.13-μm CMOS process occupies an area of 1.2 mm ×2 mm and consumes 50 μW. The power sensitivity of the whole system is -4 dBm. The sensor tag achieves a measured glucose range of 0-30 mM with a sensitivity of 0.75 nA/mM.

A non-invasive photoacoustic and ultrasonic method for the measurement of glucose solution concentration

NASA Astrophysics Data System (ADS)

Zhao, Siwei; Tao, Wei; He, Qiaozhi; Zhao, Hui; Cao, Wenwu

2017-03-01

Diabetes mellitus (DM) is a chronic disease affecting nearly 400 million people worldwide. In order to manage the disease, patients need to monitor the blood glucose level by puncturing the finger several times a day, which is uncomfortable and inconvenient. We present here a potential non-invasive monitoring method based on the velocity of ultrasonic waves generated in glucose solution by the photoacoustic principal, which can recognize the glucose concentration down to 20mg/dL. In order to apply this method to warm bodies, we carefully designed the experiment and performed measurements from 30 °C to 50 °C to generate a set of calibration curves, which may be used by engineers to build devices. Most importantly, we have theoretically explained the relationship between the compressibility and the glucose concentration. Our results show that the compressibility of solution decreases with the glucose concentration, which clarified the controversy between theory and experiment results in the literature. The derived formula is generally validity, which can be used to nondestructively measure solution concentration for other types of solutions using photoacoustic principle.

Rapid fluctuations in extracellular brain glucose levels induced by natural arousing stimuli and intravenous cocaine: fueling the brain during neural activation

PubMed Central

Lenoir, Magalie

2012-01-01

Glucose, a primary energetic substrate for neural activity, is continuously influenced by two opposing forces that tend to either decrease its extracellular levels due to enhanced utilization in neural cells or increase its levels due to entry from peripheral circulation via enhanced cerebral blood flow. How this balance is maintained under physiological conditions and changed during neural activation remains unclear. To clarify this issue, enzyme-based glucose sensors coupled with high-speed amperometry were used in freely moving rats to evaluate fluctuations in extracellular glucose levels induced by brief audio stimulus, tail pinch (TP), social interaction with another rat (SI), and intravenous cocaine (1 mg/kg). Measurements were performed in nucleus accumbens (NAcc) and substantia nigra pars reticulata (SNr), which drastically differ in neuronal activity. In NAcc, where most cells are powerfully excited after salient stimulation, glucose levels rapidly (latency 2–6 s) increased (30–70 μM or 6–14% over baseline) by all stimuli; the increase differed in magnitude and duration for each stimulus. In SNr, where most cells are transiently inhibited by salient stimuli, TP, SI, and cocaine induced a biphasic glucose response, with the initial decrease (−20–40 μM or 5–10% below baseline) followed by a reboundlike increase. The critical role of neuronal activity in mediating the initial glucose response was confirmed by monitoring glucose currents after local microinjections of glutamate (GLU) or procaine (PRO). While intra-NAcc injection of GLU transiently increased glucose levels in this structure, intra-SNr PRO injection resulted in rapid, transient decreases in SNr glucose. Therefore, extracellular glucose levels in the brain change very rapidly after physiological and pharmacological stimulation, the response is structure specific, and the pattern of neuronal activity appears to be a critical factor determining direction and magnitude of physiological fluctuations in glucose levels. PMID:22723672

Use of a subcutaneous glucose sensor to detect decreases in glucose concentration prior to observation in blood.

PubMed

Thomé-Duret, V; Reach, G; Gangnerau, M N; Lemonnier, F; Klein, J C; Zhang, Y; Hu, Y; Wilson, G S

1996-11-01

The development of a hypoglycemic alarm system using a subcutaneous glucose sensor implies that a decrease in blood glucose is rapidly followed by a decrease in the signal generated by the sensor. In a first set of experiments the linearity and the kinetics of the response of sensors implanted in the subcutaneous tissue of normal rats were investigated during a progressive increase in plasma glucose concentration: the sensitivities determined between 5 and 10 mM and between 10 and 15 mM were not significantly different, and a 5-10 min delay in the sensor's response was observed. In a second set of experiments, performed in diabetic rats, the kinetics of the decrease in subcutaneous glucose concentration following insulin administration was monitored during a decrease in plasma glucose level, from 15 to 3 mmol/L. During the 20 first min following insulin administration, the sensor monitored glucose concentration in subcutaneous tissue with no lag time. Subsequently, the decrease in the estimation of subcutaneous glucose concentration preceded that of plasma glucose. This phenomenon was not observed when the same sensors were investigated in vitro during a similar decrease in glucose concentration and may be due to a mechanism occurring in vivo, such as the effect of insulin on glucose transfer from the interstitial space to the cells surrounding the sensor. It reinforces the interest of the use of implantable glucose sensors as a part of a hypoglycemic alarm.

Enteral nutrition increases interstitial brain glucose levels in poor-grade subarachnoid hemorrhage patients.

PubMed

Kofler, Mario; Schiefecker, Alois J; Beer, Ronny; Gaasch, Maxime; Rhomberg, Paul; Stover, John; Pfausler, Bettina; Thomé, Claudius; Schmutzhard, Erich; Helbok, Raimund

2018-03-01

Low brain tissue glucose levels after acute brain injury are associated with poor outcome. Whether enteral nutrition (EN) reliably increases cerebral glucose levels remains unclear. In this retrospective analysis of prospectively collected observational data, we investigate the effect of EN on brain metabolism in 17 poor-grade subarachnoid hemorrhage (SAH) patients undergoing cerebral microdialysis (CMD) monitoring. CMD-values were obtained hourly. A nutritional intervention was defined as the clinical routine administration of EN without supplemental parenteral nutrition. Sixty-three interventions were analyzed. The mean amount of EN per intervention was 472.4 ± 10.7 kcal. CMD-glucose levels significantly increased from 1.59 ± 0.13 mmol/l at baseline to a maximum of 2.03 ± 0.2 mmol/l after 5 h (p < 0.001), independently of insulin-treatment, baseline serum glucose, baseline brain metabolic distress (CMD-lactate-to-pyruvate-ratio (LPR) > 40) and the microdialysis probe location. The increase in CMD-glucose was directly dependent on the magnitude of increase of serum glucose levels (p = 0.007). No change in CMD-lactate, CMD-pyruvate, CMD-LPR, or CMD-glutamate (p > 0.4) was observed. Routine EN also increased CMD-glucose even if baseline concentrations were critically low ( < 0.7 mmol/l, neuroglucopenia; p < 0.001). These results may have treatment implications regarding glucose management of poor-grade aneurysmal SAH patients.

A Promising Solution to Enhance the Sensocompatibility of Biosensors in Continuous Glucose Monitoring Systems

PubMed Central

van den Bosch, Edith E.M.; de Bont, Nik H.M.; Qiu, Jun; Gelling, Onko-Jan

2013-01-01

Background Continuous glucose monitors (CGMs) measure glucose in real time, making it possible to improve glycemic control. A promising technique involves glucose sensors implanted in subcutaneous tissue measuring glucose concentration in interstitial fluid. A major drawback of this technique is sensor bioinstability, which can lead to unpredictable drift and reproducibility. The bioinstability is partly due to sensor design but is also affected by naturally occurring subcutaneous inflammations. Applying a nonbiofouling coating to the sensor membrane could be a means to enhancing sensocompatibility. Methods This study evaluates the suitability of a polyethylene-glycol-based coating on sensors in CGMs. Methods used include cross hatch, wet paper rub, paper double rub, bending, hydrophilicity, protein adsorption, bio-compatibility, hemocompatibility, and glucose/oxygen permeability testing. Results Results demonstrate that coating homogeneity, adhesion, integrity, and scratch resistance are good. The coating repels lysozyme and bovine serum albumin, and only a low level of fibrin and blood platelet adsorption to the coating was recorded when testing in whole human blood. Cytotoxicity, irritation, sensitization, and hemolysis were assessed, and levels suggested good biocompatibility of the coating in subcutaneous tissue. Finally, it was shown that the coating can be applied to cellulose acetate membranes of different porosity without changing their permeability for glucose and oxygen. Conclusions These results suggest that the mechanical properties of the coating are sufficient for the given application, that the coating is effective in preventing protein adsorption and blood clot formation on the sensor surface, and that the coating can be applied to membranes without hindering their glucose and oxygen transport. PMID:23567005

Sensor-Augmented Insulin Pumps and Hypoglycemia Prevention in Type 1 Diabetes

PubMed Central

Steineck, Isabelle; Ranjan, Ajenthen; Nørgaard, Kirsten; Schmidt, Signe

2016-01-01

Hypoglycemia can lead to seizures, unconsciousness, or death. Insulin pump treatment reduces the frequency of severe hypoglycemia compared with multiple daily injections treatment. The addition of a continuous glucose monitor, so-called sensor-augmented pump (SAP) treatment, has the potential to further limit the duration and severity of hypoglycemia as the system can detect and in some systems act on impending and prevailing low blood glucose levels. In this narrative review we summarize the available knowledge on SAPs with and without automated insulin suspension, in relation to hypoglycemia prevention. We present evidence from randomized trials, observational studies, and meta-analyses including nonpregnant individuals with type 1 diabetes mellitus. We also outline concerns regarding SAPs with and without automated insulin suspension. There is evidence that SAP treatment reduces episodes of moderate and severe hypoglycemia compared with multiple daily injections plus self-monitoring of blood glucose. There is some evidence that SAPs both with and without automated suspension reduces the frequency of severe hypoglycemic events compared with insulin pumps without continuous glucose monitoring. PMID:28264173

Correlation of salivary glucose level with blood glucose level in diabetes mellitus

PubMed Central

Gupta, Shreya; Nayak, Meghanand T; Sunitha, JD; Dawar, Geetanshu; Sinha, Nidhi; Rallan, Neelakshi Singh

2017-01-01

Background: Saliva is a unique fluid, which is important for normal functioning of the oral cavity. Diabetes mellitus (DM) is a disease of absolute or relative insulin deficiency characterized by insufficient secretion of insulin by pancreatic beta-cells. The diagnosis of diabetes through blood is difficult in children, older adults, debilitated and chronically ill patients, so diagnosis by analysis of saliva can be potentially valuable as collection of saliva is noninvasive, easier and technically insensitive, unlike blood. The aim of the study was to correlate blood glucose level (BGL) and salivary glucose level (SGL) in DM patients. Methodology: A cross-sectional study was conducted in 120 patients, who were categorized as 40 controlled diabetics, 40 uncontrolled diabetics and 40 healthy, age- and sex-matched individuals constituted the controls. The blood and unstimulated saliva samples were collected from the patients at the different intervals for fasting, random and postprandial levels. These samples were then subjected for analysis of glucose in blood and saliva using glucose oxidase/peroxidase reagent in HITACHI 902(R) Automatic analyzer, and the results were recorded. Results: The mean SGLs were higher in uncontrolled and controlled diabetic groups than in nondiabetic group. A highly statistically significant correlation was found between fasting saliva glucose and fasting blood glucose in all the groups. Conclusion: With increase in BGL, increase in SGL was observed in patients with diabetes suggesting that SGL can be used for monitoring glycemic level in DM. PMID:29391704

Is management of hyperglycaemia in acute phase stroke still a dilemma?

PubMed

Savopoulos, C; Kaiafa, G; Kanellos, I; Fountouki, A; Theofanidis, D; Hatzitolios, A I

2017-05-01

Close monitoring of blood glucose levels during the immediate post-acute stroke phase is of great clinical value, as there is evidence that the risk of neurological deterioration is associated with both hyper- and hypoglycaemia. The aim of this review paper is to summarise the evidence on post-stroke blood glucose management and its impact on clinical outcomes, during the early post-acute stage. Post-stroke hyperglycaemia has been associated with increased cerebral oedema, haemorrhagic transformation, lower likelihood of recanalisation and deteriorating neurological state. Thus, hyperglycaemia during an acute stroke may result in poorer clinical outcomes, infarct progression, poor functional recovery and increased mortality rates. Although hypoglycaemia may also lead to poorer outcomes via further brain injury, it can be readily reversed by glucose administration. In most patients, the goal of regular treatment is euglycaemia and for acute-stroke patients, a reasonable approach is to target control of glucose level at 100-150 mg/dL. Both hypoglycaemia and hyperglycaemia may lead to further brain injury and clinical deterioration; that is the reason these conditions should be avoided after stroke. Yet, when correcting hyperglycaemia, great care should be taken not to switch the patient into hypoglycaemia, and subsequently aggressive insulin administration treatment should be avoided. Early identification and prompt management of hyperglycaemia, especially in acute ischaemic stroke, is recommended. Although the appropriate level of blood glucose during acute stroke is still debated, a reasonable approach is to keep the patient in a mildly hyperglycaemic state, rather than risking hypoglycaemia, using continuous glucose monitoring.

Blood Glucose Monitoring as a Teaching Tool for Endocrinology: A New Perspective

ERIC Educational Resources Information Center

Moats, Robert K., II

2009-01-01

The education of new allied health professionals and nurses in proper endocrine evaluation and care has become critical in recent years, especially considering the greatly increased prevalence of diabetes in adults and children. The evaluation of blood glucose levels in human volunteers over time is a powerful teaching tool for endocrinology that…

Efficacy of combination herbal product (Curcuma longa and Eugenia jambolana) used for diabetes mellitus.

PubMed

Rao, Sadia Saleem; Najam, Rahila

2016-01-01

The purpose of this research was to evaluate the efficacy of a combination herbal product that is traditionally used for managing diabetes mellitus. Herbal drug contains Curcuma longa and Eugenia jambolanain the ratio of 1:1. It was orally administered at the dose of 1082 mg/70 kg twice a day for a period of 6 weeks to alloxan induced diabetic rats and compared with glibenclamide (standard). The effects of drug were observed at intervals, with respect to random and fasting glucose levels. HbA1C was also monitored after the drug treatment to monitor the overall diabetic effect. Results revealed that the combination of two herbs significantly reduced fasting and random glucose levels with HbA1C of less than 6% (p<0.001) in comparison to diabetic control. The control of fasting blood glucose levels by herbal combination is similar to the standard drug, glibenclamide (p<0.05). Random glucose levels by herbal combination is better than standard drug after one week and six weeks of treatment (p<0.01 and p<0.001 respectively) and similar after third week of treatment (p<0.05). Also, herbal drug combination showed HbA1C closer to the standard drug. It shows that this herbal combination can be of potential benefit in managing diabetes mellitus in future.

Effects of sitagliptin or mitiglinide as an add-on to acarbose on daily blood glucose fluctuations measured by 72 h subcutaneous continuous glucose monitoring in Japanese patients with type 2 diabetes: a prospective randomized study.

PubMed

Osonoi, Takeshi; Saito, Miyoko; Tamasawa, Atsuko; Ishida, Hidenori; Osonoi, Yusuke

2014-07-01

Postprandial hyperglycemia and blood glucose fluctuations increase the risk of macroangiopathy in patients with type 2 diabetes mellitus (T2DM). However, few studies have examined the effects of oral hypoglycemic drugs on blood glucose fluctuations in daily life. Twenty-nine T2DM patients treated with acarbose were randomized to receive either sitagliptin (14 patients) or mitiglinide (15 patients) together with acarbose for 4 weeks. Patients were then switched to a combination of 10 mg mitiglinide and 0.2 mg voglibose for 4 weeks. All patients wore a continuous glucose monitoring (CGM) device for 5 - 7 days in week 3 of each treatment period. The percentage of blood glucose levels in the hyperglycemic range, blood glucose indices derived from 24-h CGM profiles and the glycemic parameters (HbA1c, glycated albumin and fasting plasma glucose) were significantly improved by adding sitagliptin or mitiglinide to ongoing acarbose therapy. These parameters also tended to improve in the mitiglinide/voglibose combination period. Daily blood glucose fluctuations were significantly improved by adding sitagliptin or mitiglinide to acarbose, and improved after switching to the mitiglinide/voglibose combination. Larger controlled studies are needed to verify the effects of adding sitagliptin or mitiglinide to acarbose on glucose fluctuations.

Characterization of micro-resonator based on enhanced metal insulator semiconductor capacitor for glucose recognition.

PubMed

Dhakal, Rajendra; Kim, E S; Jo, Yong-Hwa; Kim, Sung-Soo; Kim, Nam-Young

2017-03-01

We present a concept for the characterization of micro-fabricated based resonator incorporating air-bridge metal-insulator-semiconductor (MIS) capacitor to continuously monitor an individual's state of glucose levels based on frequency variation. The investigation revealed that, the micro-resonator based on MIS capacitor holds considerable promise for implementation and recognition as a glucose sensor for human serum. The discrepancy in complex permittivity as a result of enhanced capacitor was achieved for the detection and determination of random glucose concentration levels using a unique variation of capacitor that indeed results in an adequate variation of the resonance frequency. Moreover, the design and development of micro-resonator with enhanced MIS capacitor generate a resolution of 112.38 × 10 -3 pF/mg/dl, minimum detectable glucose level of 7.45mg/dl, and a limit of quantification of 22.58mg/dl. Additionally, this unique approach offers long-term reliability for mediator-free glucose sensing with a relative standard deviation of less than 0.5%. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Comparative effectiveness and safety of methods of insulin delivery and glucose monitoring for diabetes mellitus: a systematic review and meta-analysis.

PubMed

Yeh, Hsin-Chieh; Brown, Todd T; Maruthur, Nisa; Ranasinghe, Padmini; Berger, Zackary; Suh, Yong D; Wilson, Lisa M; Haberl, Elisabeth B; Brick, Jessica; Bass, Eric B; Golden, Sherita Hill

2012-09-04

Patients with diabetes mellitus need information about the effectiveness of innovations in insulin delivery and glucose monitoring. To review how intensive insulin therapy (multiple daily injections [MDI] vs. rapid-acting analogue-based continuous subcutaneous insulin infusion [CSII]) or method of monitoring (self-monitoring of blood glucose [SMBG] vs. real-time continuous glucose monitoring [rt-CGM]) affects outcomes in types 1 and 2 diabetes mellitus. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials through February 2012 without language restrictions. 33 randomized, controlled trials in children or adults that compared CSII with MDI (n=19), rt-CGM with SMBG (n=10), or sensor-augmented insulin pump use with MDI and SMBG (n=4). 2 reviewers independently evaluated studies for eligibility and quality and serially abstracted data. In randomized, controlled trials, MDI and CSII showed similar effects on hemoglobin A1c (HbA1c) levels and severe hypoglycemia in children or adults with type 1 diabetes mellitus and adults with type 2 diabetes mellitus. In adults with type 1 diabetes mellitus, HbA1c levels decreased more with CSII than with MDI, but 1 study heavily influenced these results. Compared with SMBG, rt-CGM achieved a lower HbA1c level (between-group difference of change, 0.26% [95% CI, 0.33% to 0.19%]) without any difference in severe hypoglycemia. Sensor-augmented insulin pump use decreased HbA1c levels more than MDI and SMBG did in persons with type 1 diabetes mellitus (between-group difference of change, 0.68% [CI, 0.81% to 0.54%]). Little evidence was available on other outcomes. Many studies were small, of short duration, and limited to white persons with type 1 diabetes mellitus. Continuous subcutaneous insulin infusion and MDI have similar effects on glycemic control and hypoglycemia, except CSII has a favorable effect on glycemic control in adults with type 1 diabetes mellitus. For glycemic control, rt-CGM is superior to SMBG and sensor-augmented insulin pumps are superior to MDI and SMBG without increasing the risk for hypoglycemia. Agency for Healthcare Research and Quality.

In vivo continuous and simultaneous monitoring of brain energy substrates with a multiplex amperometric enzyme-based biosensor device.

PubMed

Cordeiro, C A; de Vries, M G; Ngabi, W; Oomen, P E; Cremers, T I F H; Westerink, B H C

2015-05-15

Enzyme-based amperometric biosensors are widely used for monitoring key biomarkers. In experimental neuroscience there is a growing interest in in vivo continuous and simultaneous monitoring of metabolism-related biomarkers, like glucose, lactate and pyruvate. The use of multiplex biosensors will provide better understanding of brain energy metabolism and its role in neuropathologies such as diabetes, ischemia, and epilepsy. We have developed and characterized an implantable multiplex microbiosensor device (MBD) for simultaneous and continuous in vivo monitoring of glucose, lactate, and pyruvate. First, we developed and characterized amperometric microbiosensors for monitoring lactate and pyruvate. In vitro evaluation allowed us to choose the most suitable biosensors for incorporation into the MBD, along with glucose and background biosensors. Fully assembled MBDs were characterized in vitro. The calculated performance parameters (LOD, LR, LRS, IMAX and appKM) showed that the multiplex MBD was highly selective and sensitive (LRS≥100 nA/mM) for each analyte and within an adequate range for in vivo application. Finally, MBDs were implanted in the mPFC of anesthetized adult male Wistar rats for in vivo evaluation. Following an equilibration period, baseline brain levels of glucose (1.3±0.2 mM), lactate (1.5±0.4 mM) and pyruvate (0.3±0.1 mM) were established. Subsequently, the MBDs recorded the responses of the animals when submitted to hyperglycemic (40% glucose i.v.) and hypoglycemic (5 U/kg insulin i.v.) challenges. Afterwards, MBDs were recalibrated to convert electrochemical readings into accurate substrate concentrations and to assess biofouling. The presented MBD can monitor simultaneously multiple biomarkers in vivo. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of pH, lactate, hematocrit and potassium level on the accuracy of continuous glucose monitoring (CGM) in pediatric intensive care unit.

PubMed

Marics, Gábor; Koncz, Levente; Eitler, Katalin; Vatai, Barbara; Szénási, Boglárka; Zakariás, David; Mikos, Borbála; Körner, Anna; Tóth-Heyn, Péter

2015-03-19

Continuous glucose monitoring (CGM) originally was developed for diabetic patients and it may be a useful tool for monitoring glucose changes in pediatric intensive care unit (PICU). Its use is, however, limited by the lack of sufficient data on its reliability at insufficient peripheral perfusion. We aimed to correlate the accuracy of CGM with laboratory markers relevant to disturbed tissue perfusion. In 38 pediatric patients (age range, 0-18 years) requiring intensive care we tested the effect of pH, lactate, hematocrit and serum potassium on the difference between CGM and meter glucose measurements. Guardian® (Medtronic®) CGM results were compared to GEM 3000 (Instrumentation laboratory®) and point-of-care measurements. The clinical accuracy of CGM was evaluated by Clarke Error Grid -, Bland-Altman analysis and Pearson's correlation. We used Friedman test for statistical analysis (statistical significance was established as a p < 0.05). CGM values exhibited a considerable variability without any correlation with the examined laboratory parameters. Clarke, Bland-Altman analysis and Pearson's correlation coefficient demonstrated a good clinical accuracy of CGM (zone A and B = 96%; the mean difference between reference and CGM glucose was 1,3 mg/dL, 48 from the 780 calibration pairs overrunning the 2 standard deviation; Pearson's correlation coefficient: 0.83). The accuracy of CGM measurements is independent of laboratory parameters relevant to tissue hypoperfusion. CGM may prove a reliable tool for continuous monitoring of glucose changes in PICUs, not much influenced by tissue perfusion, but still not appropriate for being the base for clinical decisions.

Using LSTMs to learn physiological models of blood glucose behavior.

PubMed

Mirshekarian, Sadegh; Bunescu, Razvan; Marling, Cindy; Schwartz, Frank

2017-07-01

For people with type 1 diabetes, good blood glucose control is essential to keeping serious disease complications at bay. This entails carefully monitoring blood glucose levels and taking corrective steps whenever they are too high or too low. If blood glucose levels could be accurately predicted, patients could take proactive steps to prevent blood glucose excursions from occurring. However, accurate predictions require complex physiological models of blood glucose behavior. Factors such as insulin boluses, carbohydrate intake, and exercise influence blood glucose in ways that are difficult to capture through manually engineered equations. In this paper, we describe a recursive neural network (RNN) approach that uses long short-term memory (LSTM) units to learn a physiological model of blood glucose. When trained on raw data from real patients, the LSTM networks (LSTMs) obtain results that are competitive with a previous state-of-the-art model based on manually engineered physiological equations. The RNN approach can incorporate arbitrary physiological parameters without the need for sophisticated manual engineering, thus holding the promise of further improvements in prediction accuracy.

Glucose Sensing for Diabetes Monitoring: Recent Developments

PubMed Central

Bruen, Danielle; Delaney, Colm; Florea, Larisa

2017-01-01

This review highlights recent advances towards non-invasive and continuous glucose monitoring devices, with a particular focus placed on monitoring glucose concentrations in alternative physiological fluids to blood. PMID:28805693

Comparison of Glucose Area Under the Curve Measured Using Minimally Invasive Interstitial Fluid Extraction Technology with Continuous Glucose Monitoring System in Diabetic Patients

PubMed Central

Uemura, Mei; Suzuki, Toshinari; Yasuma, Taro; Sato, Toshiyuki; Morimoto, Aya; Hosoya, Samiko; Suminaka, Chihiro; Nakajima, Hiromu; Gabazza, Esteban C.; Takei, Yoshiyuki

2017-01-01

Background Continuous glucose monitoring (CGM) is reported to be a useful technique, but difficult or inconvenient for some patients and institutions. We are developing a glucose area under the curve (AUC) monitoring system without blood sampling using a minimally invasive interstitial fluid extraction technology (MIET). Here we evaluated the accuracy of interstitial fluid glucose (IG) AUC measured by MIET in patients with diabetes for an extended time interval and the potency of detecting hyperglycemia using CGM data as a reference. Methods Thirty-eight inpatients with diabetes undergoing CGM were enrolled. MIET comprised a pretreatment step using a plastic microneedle array and glucose accumulation step with a hydrogel patch, which was placed on two sites from 9:00 AM to 5:00 PM or from 10:00 PM to 6:00 AM. IG AUC was calculated by accumulated glucose extracted by hydrogel patches using sodium ion as standard. Results A significant correlation was observed between the predicted AUC by MIET and CGM in daytime (r=0.76) and nighttime (r=0.82). The optimal cutoff for the IG AUC value of MIET to predict hyperglycemia over 200 mg/dL measured by CGM for 8 hours was 1,067.3 mg·hr/dL with 88.2% sensitivity and 81.5% specificity. Conclusion We showed that 8-hour IG AUC levels using MIET were valuable in estimating the blood glucose AUC without blood sampling. The results also supported the concept of using this technique for evaluating glucose excursion and for screening hyperglycemia during 8 hours in patients with diabetes at any time of day. PMID:28868824

Comparison of Glucose Area Under the Curve Measured Using Minimally Invasive Interstitial Fluid Extraction Technology with Continuous Glucose Monitoring System in Diabetic Patients.

PubMed

Uemura, Mei; Yano, Yutaka; Suzuki, Toshinari; Yasuma, Taro; Sato, Toshiyuki; Morimoto, Aya; Hosoya, Samiko; Suminaka, Chihiro; Nakajima, Hiromu; Gabazza, Esteban C; Takei, Yoshiyuki

2017-08-01

Continuous glucose monitoring (CGM) is reported to be a useful technique, but difficult or inconvenient for some patients and institutions. We are developing a glucose area under the curve (AUC) monitoring system without blood sampling using a minimally invasive interstitial fluid extraction technology (MIET). Here we evaluated the accuracy of interstitial fluid glucose (IG) AUC measured by MIET in patients with diabetes for an extended time interval and the potency of detecting hyperglycemia using CGM data as a reference. Thirty-eight inpatients with diabetes undergoing CGM were enrolled. MIET comprised a pretreatment step using a plastic microneedle array and glucose accumulation step with a hydrogel patch, which was placed on two sites from 9:00 AM to 5:00 PM or from 10:00 PM to 6:00 AM. IG AUC was calculated by accumulated glucose extracted by hydrogel patches using sodium ion as standard. A significant correlation was observed between the predicted AUC by MIET and CGM in daytime (r=0.76) and nighttime (r=0.82). The optimal cutoff for the IG AUC value of MIET to predict hyperglycemia over 200 mg/dL measured by CGM for 8 hours was 1,067.3 mg·hr/dL with 88.2% sensitivity and 81.5% specificity. We showed that 8-hour IG AUC levels using MIET were valuable in estimating the blood glucose AUC without blood sampling. The results also supported the concept of using this technique for evaluating glucose excursion and for screening hyperglycemia during 8 hours in patients with diabetes at any time of day. Copyright © 2017 Korean Diabetes Association

First Clinical Experience with Retrospective Flash Glucose Monitoring (FGM) Analysis in South Africa

PubMed Central

Distiller, Larry A.; Cranston, Iain; Mazze, Roger

2016-01-01

Background: In 2014, an innovative blinded continuous glucose monitoring system was introduced with automated ambulatory glucose profile (AGP) reporting. The clinical use and interpretation of this new technology has not previously been described. Therefore we wanted to understand its use in characterizing key factors related to glycemic control: glucose exposure, variability, and stability, and risk of hypoglycemia in clinical practice. Methods: Clinicians representing affiliated diabetes centers throughout South Africa were trained and subsequently were given flash glucose monitoring readers and 2-week glucose sensors to use at their discretion. After patient use, sensor data were collected and uploaded for AGP reporting. Results: Complete data (sensor AGP with corresponding clinical information) were obtained for 50 patients with type 1 (70%) and type 2 diabetes (30%), irrespective of therapy. Aggregated analysis of AGP data comparing patients with type 1 versus type 2 diabetes, revealed that despite similar HbA1c values between both groups (8.4 ± 2 vs 8.6 ± 1.7%, respectively), those with type 2 diabetes had lower mean glucose levels (9.2 ± 3 vs 10.3 mmol/l [166 ± 54 vs 185 mg/dl]) and lower indices of glucose variability (3.0 ± 1.5 vs 5.0 ± 1.9 mmol/l [54 ± 27 vs 90 ± 34.2 mg/dl]). This highlights key areas for future focus. Conclusions: Using AGP, the characteristics of glucose exposure, variability, stability, and hypoglycemia risk and occurrence were obtained within a short time and with minimal provider and patient input. In a survey at the time of the follow-up visit, clinicians indicated that aggregated AGP data analysis provided important new clinical information and insights. PMID:27154973

Brain Activation in Response to Personalized Behavioral and Physiological Feedback From Self-Monitoring Technology: Pilot Study

PubMed Central

Morgan, Paul S; Sherar, Lauren B; Kingsnorth, Andrew P; Magistro, Daniele; Esliger, Dale W

2017-01-01

Background The recent surge in commercially available wearable technology has allowed real-time self-monitoring of behavior (eg, physical activity) and physiology (eg, glucose levels). However, there is limited neuroimaging work (ie, functional magnetic resonance imaging [fMRI]) to identify how people’s brains respond to receiving this personalized health feedback and how this impacts subsequent behavior. Objective Identify regions of the brain activated and examine associations between activation and behavior. Methods This was a pilot study to assess physical activity, sedentary time, and glucose levels over 14 days in 33 adults (aged 30 to 60 years). Extracted accelerometry, inclinometry, and interstitial glucose data informed the construction of personalized feedback messages (eg, average number of steps per day). These messages were subsequently presented visually to participants during fMRI. Participant physical activity levels and sedentary time were assessed again for 8 days following exposure to this personalized feedback. Results Independent tests identified significant activations within the prefrontal cortex in response to glucose feedback compared with behavioral feedback (P<.001). Reductions in mean sedentary time (589.0 vs 560.0 minutes per day, P=.014) were observed. Activation in the subgyral area had a moderate correlation with minutes of moderate-to-vigorous physical activity (r=0.392, P=.043). Conclusion Presenting personalized glucose feedback resulted in significantly more brain activation when compared with behavior. Participants reduced time spent sedentary at follow-up. Research on deploying behavioral and physiological feedback warrants further investigation. PMID:29117928

The Surveillance Error Grid

PubMed Central

Lias, Courtney; Vigersky, Robert; Clarke, William; Parkes, Joan Lee; Sacks, David B.; Kirkman, M. Sue; Kovatchev, Boris

2014-01-01

Introduction: Currently used error grids for assessing clinical accuracy of blood glucose monitors are based on out-of-date medical practices. Error grids have not been widely embraced by regulatory agencies for clearance of monitors, but this type of tool could be useful for surveillance of the performance of cleared products. Diabetes Technology Society together with representatives from the Food and Drug Administration, the American Diabetes Association, the Endocrine Society, and the Association for the Advancement of Medical Instrumentation, and representatives of academia, industry, and government, have developed a new error grid, called the surveillance error grid (SEG) as a tool to assess the degree of clinical risk from inaccurate blood glucose (BG) monitors. Methods: A total of 206 diabetes clinicians were surveyed about the clinical risk of errors of measured BG levels by a monitor. The impact of such errors on 4 patient scenarios was surveyed. Each monitor/reference data pair was scored and color-coded on a graph per its average risk rating. Using modeled data representative of the accuracy of contemporary meters, the relationships between clinical risk and monitor error were calculated for the Clarke error grid (CEG), Parkes error grid (PEG), and SEG. Results: SEG action boundaries were consistent across scenarios, regardless of whether the patient was type 1 or type 2 or using insulin or not. No significant differences were noted between responses of adult/pediatric or 4 types of clinicians. Although small specific differences in risk boundaries between US and non-US clinicians were noted, the panel felt they did not justify separate grids for these 2 types of clinicians. The data points of the SEG were classified in 15 zones according to their assigned level of risk, which allowed for comparisons with the classic CEG and PEG. Modeled glucose monitor data with realistic self-monitoring of blood glucose errors derived from meter testing experiments plotted on the SEG when compared to the data plotted on the CEG and PEG produced risk estimates that were more granular and reflective of a continuously increasing risk scale. Discussion: The SEG is a modern metric for clinical risk assessments of BG monitor errors that assigns a unique risk score to each monitor data point when compared to a reference value. The SEG allows the clinical accuracy of a BG monitor to be portrayed in many ways, including as the percentages of data points falling into custom-defined risk zones. For modeled data the SEG, compared with the CEG and PEG, allows greater precision for quantifying risk, especially when the risks are low. This tool will be useful to allow regulators and manufacturers to monitor and evaluate glucose monitor performance in their surveillance programs. PMID:25562886

The surveillance error grid.

PubMed

Klonoff, David C; Lias, Courtney; Vigersky, Robert; Clarke, William; Parkes, Joan Lee; Sacks, David B; Kirkman, M Sue; Kovatchev, Boris

2014-07-01

Currently used error grids for assessing clinical accuracy of blood glucose monitors are based on out-of-date medical practices. Error grids have not been widely embraced by regulatory agencies for clearance of monitors, but this type of tool could be useful for surveillance of the performance of cleared products. Diabetes Technology Society together with representatives from the Food and Drug Administration, the American Diabetes Association, the Endocrine Society, and the Association for the Advancement of Medical Instrumentation, and representatives of academia, industry, and government, have developed a new error grid, called the surveillance error grid (SEG) as a tool to assess the degree of clinical risk from inaccurate blood glucose (BG) monitors. A total of 206 diabetes clinicians were surveyed about the clinical risk of errors of measured BG levels by a monitor. The impact of such errors on 4 patient scenarios was surveyed. Each monitor/reference data pair was scored and color-coded on a graph per its average risk rating. Using modeled data representative of the accuracy of contemporary meters, the relationships between clinical risk and monitor error were calculated for the Clarke error grid (CEG), Parkes error grid (PEG), and SEG. SEG action boundaries were consistent across scenarios, regardless of whether the patient was type 1 or type 2 or using insulin or not. No significant differences were noted between responses of adult/pediatric or 4 types of clinicians. Although small specific differences in risk boundaries between US and non-US clinicians were noted, the panel felt they did not justify separate grids for these 2 types of clinicians. The data points of the SEG were classified in 15 zones according to their assigned level of risk, which allowed for comparisons with the classic CEG and PEG. Modeled glucose monitor data with realistic self-monitoring of blood glucose errors derived from meter testing experiments plotted on the SEG when compared to the data plotted on the CEG and PEG produced risk estimates that were more granular and reflective of a continuously increasing risk scale. The SEG is a modern metric for clinical risk assessments of BG monitor errors that assigns a unique risk score to each monitor data point when compared to a reference value. The SEG allows the clinical accuracy of a BG monitor to be portrayed in many ways, including as the percentages of data points falling into custom-defined risk zones. For modeled data the SEG, compared with the CEG and PEG, allows greater precision for quantifying risk, especially when the risks are low. This tool will be useful to allow regulators and manufacturers to monitor and evaluate glucose monitor performance in their surveillance programs. © 2014 Diabetes Technology Society.

Accuracy evaluation of contour next compared with five blood glucose monitoring systems across a wide range of blood glucose concentrations occurring in a clinical research setting.

PubMed

Klaff, Leslie J; Brazg, Ronald; Hughes, Kristen; Tideman, Ann M; Schachner, Holly C; Stenger, Patricia; Pardo, Scott; Dunne, Nancy; Parkes, Joan Lee

2015-01-01

This study evaluated the accuracy of Contour(®) Next (CN; Bayer HealthCare LLC, Diabetes Care, Whippany, NJ) compared with five blood glucose monitoring systems (BGMSs) across a wide range of clinically occurring blood glucose levels. Subjects (n=146) were ≥ 18 years and had type 1 or type 2 diabetes. Subjects' glucose levels were safely lowered or raised to provide a wide range of glucose values. Capillary blood samples were tested on six BGMSs and a YSI glucose analyzer (YSI Life Sciences, Inc., Yellow Springs, OH) as the reference. Extreme glucose values were achieved by glucose modification of the blood sample. System accuracy was assessed by mean absolute difference (MAD) and mean absolute relative difference (MARD) across several glucose ranges, with <70 mg/dL evaluated by MAD as the primary end point. In the low glucose range (<70 mg/dL), MAD values were as follows: Accu-Chek(®) Aviva Nano (Roche Diagnostics, Indianapolis, IN), 3.34 mg/dL; CN, 2.03 mg/dL; FreeStyle Lite(®) (FSL; Abbott Diabetes Care, Inc., Alameda, CA), 2.77 mg/dL; OneTouch(®) Ultra(®) 2 (LifeScan, Inc., Milpitas, CA), 10.20 mg/dL; OneTouch(®) Verio(®) Pro (LifeScan, Inc.), 4.53 mg/dL; and Truetrack(®) (Nipro Diagnostics, Inc., Fort Lauderdale, FL), 11.08 mg/dL. The lowest MAD in the low glucose range, from CN, was statistically significantly lower than those of the other BGMSs with the exception of the FSL. CN also had a statistically significantly lower MARD than all other BGMSs in the low glucose range. In the overall glucose range (21-496 mg/dL), CN yielded the lowest MAD and MARD values, which were statistically significantly lower in comparison with the other BGMSs. When compared with other BGMSs, CN demonstrated the lowest mean deviation from the reference value (by MAD and MARD) across multiple glucose ranges.

Measurement of diabetic sugar concentration in human blood using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Firdous, S.; Nawaz, M.; Ahmed, M.; Anwar, S.; Rehman, A.; Rashid, R.; Mahmood, A.

2012-06-01

This study demonstrates the use of Raman spectroscopy for the direct measurement of diabetic sugar in human blood using 532 nm laser system. Raman spectra were collected from whole blood drawn from 21 individuals. We have elicited a reliable glucose signature in diabetic patients, and measured glucose levels in blood serum of normal, healthy diabetic and diabetic patients with other malignancies like cancer and hepatitis. Quantitative predictions of glucose spectra illustrate the predictions based on molecular information carried by the Raman light in highly light-scattering and absorbing media. Raman spectrum peaks for diabetic blood serum are observed at 1168, 1531, 1463, 1021 cm-1 with intensity level 17000 to 18500 pixels attributed to carbohydrates, proteins, lipids, collagen, and skeletal C-C stretch of lipids acyl chains. Raman spectra for normal, diabetic patients having cancer and hepatitis were also recorded. This in vitro glucose monitoring methodology will lead in vivo noninvasive on-line monitoring having painless and at the same time the data will be displayed on-line and in real time. The measured Raman peaks provides detailed bio-chemical fingerprint of the sample and could confer diagnostic benefit in a clinical setting.

Fabrication and characterization of spiral interdigitated electrodes based biosensor for salivary glucose detection

NASA Astrophysics Data System (ADS)

Adelyn, P. Y. P.; Hashim, U.; Arshad, M. K. Md; Voon, C. H.; Liu, Wei-Wen; Kahar, S. M.; Huda, A. R. N.; Lee, H. Cheun

2017-03-01

This work introduces the non-invasive glucose monitoring technique by using the Complementary Metal Oxide Semiconductor (CMOS) technologically fabricated spiral Interdigitated Electrodes (IDE) based biosensor. Scanning Electron Microscopy (SEM) image explores the morphology of spiral IDE while Energy Dispersive X-Ray (EDX) determines the elements induced in spiral IDE. Oral saliva of two patients are collected and tested on the spiral IDE sensor with electrical characterization as glucose detection results. However, both patients exhibit their glucose level characteristics inconsistently. Therefore, this work could be extended and enhanced by adding Glutaraldehyde in between 3-Aminoproply)triethoxysilane (APTES) modified and glucose oxidase (GOD) enzyme immobilized layer with FTIR validation for bonding attachment.

Effect of disinfectants on glucose monitors.

PubMed

Mahoney, John J; Lim, Christine G

2012-01-01

Monitoring blood glucose levels is an integral part of routine diabetes management. To minimize the risk of transmission of bloodborne pathogens during monitoring, the Centers for Disease Control and Prevention (CDC) recommends that glucose meters be disinfected after each use whenever they are used to test multiple patients. The objective of this study is to assess the compatibility of some common disinfectants with certain blood glucose meter systems. We tested six disinfectants for adverse impact on meter performance or the exterior meter surfaces. The disinfectants tested were 0.525% sodium hypochlorite, 20% 2-propanol and 10% ethanol, 17.2% isopropanol, 55% isopropanol, 70% isopropanol, and hydrogen peroxide. To assess meter performance, we tested OneTouch® Ultra® blood glucose monitoring systems with control solution before and after application of either water or disinfectant. To assess the effect on exterior meter surfaces, we performed a soaking test to simulate long-term exposure to disinfectant. Paired t-test results showed that the control solution data associated with disinfectant and with water application were not significantly different for each meter type. However, most of the meter types were adversely affected by hydrogen peroxide and/or by the higher concentrations of alcohol-based disinfectants. Although none of the six disinfectants affected meter performance, hydrogen peroxide and isopropanol >20% adversely affected the exterior surfaces of the tested meters. When complying with CDC instructions for meter disinfection, users should use caution and choose disinfectants that have been validated by the meter manufacturer. © 2012 Diabetes Technology Society.

[Continuous glucose monitoring with type 1 diabetes mellitus].

PubMed

López-Siguero, J P; García Arias, M J; del Pino de la Fuente, A; Moreno Molina, J A

2003-03-01

Appropriate metabolic control of children with type 1 diabetes mellitus (DM) is based on frequent measurements of capillary glycemia. However, this method offers only partial information on fluctuations in glycemia during the day, while episodes of postprandial hyperglycemia and hypoglycemia, mainly nocturnal, go unnoticed. To analyze pre- and postprandial blood glucose levels, as well as the presence and duration of hypoglycemic episodes in diabetic children aged more than 8 years old with more than one year of disease duration. Seventeen patients of both sexes (mean age: 12 years old) with type 1 DM were monitored with the continuous glucose monitoring system (CGMS) during working days. Maximum values of pre- and postprandial glucose (1-3 hours after breakfast, lunch and dinner) were registered. Data were downloaded with a Com-station. The mean duration of sensor-wearing was 2.97 days. Pre- and postprandial values were high: mean preprandial values were between 144.9 and 160.5 mg % and mean postprandial values were between 230.4 and 248.8 mg %. The mean number of hypoglycemic episodes detected with the sensor was 4.9 compared with 1.8 detected with the glucometer (p < 0.05). Episodes of mainly nocturnal asymptomatic hypoglycemia were detected with a mean duration of 145 minutes during the night and 75 minutes during the day. The use of continuous subcutaneous glucose monitoring demonstrates that glycemic objectives are not achieved by conventional insulin therapy. It also shows that there are a high number of hypoglycemic episodes, most of which are asymptomatic.

Effect of Disinfectants on Glucose Monitors

PubMed Central

Mahoney, John J; Lim, Christine G

2012-01-01

Background Monitoring blood glucose levels is an integral part of routine diabetes management. To minimize the risk of transmission of bloodborne pathogens during monitoring, the Centers for Disease Control and Prevention (CDC) recommends that glucose meters be disinfected after each use whenever they are used to test multiple patients. The objective of this study is to assess the compatibility of some common disinfectants with certain blood glucose meter systems. Methods We tested six disinfectants for adverse impact on meter performance or the exterior meter surfaces. The disinfectants tested were 0.525% sodium hypochlorite, 20% 2-propanol and 10% ethanol, 17.2% isopropanol, 55% isopropanol, 70% isopropanol, and hydrogen peroxide. To assess meter performance, we tested OneTouch® Ultra® blood glucose monitoring systems with control solution before and after application of either water or disinfectant. To assess the effect on exterior meter surfaces, we performed a soaking test to simulate long-term exposure to disinfectant. Results Paired t-test results showed that the control solution data associated with disinfectant and with water application were not significantly different for each meter type. However, most of the meter types were adversely affected by hydrogen peroxide and/or by the higher concentrations of alcohol-based disinfectants. Conclusions Although none of the six disinfectants affected meter performance, hydrogen peroxide and isopropanol >20% adversely affected the exterior surfaces of the tested meters. When complying with CDC instructions for meter disinfection, users should use caution and choose disinfectants that have been validated by the meter manufacturer. PMID:22401326

Evaluation of Blood Glucose Monitoring System in Screening for Neonatal Hypoglycemia: Tighter Accuracy Standard.

PubMed

Tsao, Mei-Fen; Chang, Hui-Wen; Chang, Chien-Hsi; Cheng, Chi-Hsuan; Lin, Hsiu-Chen

2017-05-01

Neonatal hypoglycemia may cause severe neurological damages; therefore, tight glycemic control is crucial to identify neonate at risk. Previous blood glucose monitoring system (BGMS) failed to perform well in neonates; there are calls for the tightening of accuracy requirements. It remains a need for accurate BGMS for effective bedside diabetes management in neonatal care within a hospital population. A total of 300 neonates were recruited from local hospitals. Accuracy performance of a commercially available BGMS was evaluated against reference instrument in screening for neonatal hypoglycemia, and assessment was made based on the ISO15197:2013 and a tighter standard. At blood glucose level < 47 mg/dl, BGMS assessed met the minimal accuracy requirement of ISO 15197:2013 and tighter standard at 100% and 97.2%, respectively.

Development of Cell Phone Application for Blood Glucose Self-Monitoring Based on ISO/IEEE 11073 and HL7 CCD.

PubMed

Park, Hyun Sang; Cho, Hune; Kim, Hwa Sun

2015-04-01

The objectives of this research were to develop and evaluate a cell phone application based on the standard protocol for personal health devices and the standard information model for personal health records to support effective blood glucose management and standardized service for patients with diabetes. An application was developed for Android 4.0.3. In addition, an IEEE 11073 Manager, Medical Device Encoding Rule, and Bluetooth Health Device Profile Connector were developed for standardized health communication with a glucometer, and a Continuity of Care Document (CCD) Composer and CCD Parser were developed for CCD document exchange. The developed application was evaluated by five healthcare professionals and 87 users through a questionnaire comprising the following variables: usage intention, effort expectancy, social influence, facilitating condition, perceived risk, and voluntariness. As a result of the evaluation of usability, it was confirmed that the developed application is useful for blood glucose self-monitoring by diabetic patients. In particular, the healthcare professionals stated their own views that the application is useful to observe the trends in blood glucose change through the automatic function which records a blood glucose level measured using Bluetooth function, and the function which checks accumulated records of blood glucose levels. Also, a result of the evaluation of usage intention was 3.52 ± 0.42 out of 5 points. The application developed by our research team was confirmed by the verification of healthcare professionals that accurate feedback can be provided to healthcare professionals during the management of diabetic patients or education for glucose management.

Development of Cell Phone Application for Blood Glucose Self-Monitoring Based on ISO/IEEE 11073 and HL7 CCD

PubMed Central

Park, Hyun Sang; Cho, Hune

2015-01-01

Objectives The objectives of this research were to develop and evaluate a cell phone application based on the standard protocol for personal health devices and the standard information model for personal health records to support effective blood glucose management and standardized service for patients with diabetes. Methods An application was developed for Android 4.0.3. In addition, an IEEE 11073 Manager, Medical Device Encoding Rule, and Bluetooth Health Device Profile Connector were developed for standardized health communication with a glucometer, and a Continuity of Care Document (CCD) Composer and CCD Parser were developed for CCD document exchange. The developed application was evaluated by five healthcare professionals and 87 users through a questionnaire comprising the following variables: usage intention, effort expectancy, social influence, facilitating condition, perceived risk, and voluntariness. Results As a result of the evaluation of usability, it was confirmed that the developed application is useful for blood glucose self-monitoring by diabetic patients. In particular, the healthcare professionals stated their own views that the application is useful to observe the trends in blood glucose change through the automatic function which records a blood glucose level measured using Bluetooth function, and the function which checks accumulated records of blood glucose levels. Also, a result of the evaluation of usage intention was 3.52 ± 0.42 out of 5 points. Conclusions The application developed by our research team was confirmed by the verification of healthcare professionals that accurate feedback can be provided to healthcare professionals during the management of diabetic patients or education for glucose management. PMID:25995960

Blood glucose monitoring in type 2 diabetes – Nepalese patients’ opinions and experiences

PubMed Central

Sapkota, Sujata; Brien, Jo-anne E; Aslani, Parisa

2017-01-01

ABSTRACT Background: Blood glucose monitoring forms a vital component of diabetes care. Monitoring conducted at home using glucometers, and in laboratories by professionals, are two common methods of blood glucose monitoring in clinical practice. Objective: To investigate Nepalese patients’ perceptions and practices of blood glucose monitoring in diabetes. Methods: In-depth interviews were conducted with 48 Nepalese participants with type 2 diabetes in Sydney and Kathmandu. The interviews were audio-recorded, transcribed verbatim and thematically analysed. Results: In Australia, most participants perceived home monitoring as useful; and both home and laboratory monitoring were conducted at fairly regular intervals. In Nepal, only a small number conducted home monitoring and the laboratory method formed the primary method of day-to-day monitoring. The laboratory method was preferred due to easy access to laboratories, lack of faith in glucometers and perceptions that home monitoring is costlier. However, overall monitoring was irregular in Nepal. In addition to the healthcare system which enabled cheaper self-monitoring in Australia, Nepalese in Australia also tended to have a better understanding about the purpose of home monitoring. Conclusions: This study has highlighted the disparity in perceptions and practices related to blood glucose monitoring. Understanding the importance of blood glucose monitoring and access to affordable resources are critical facilitators for conducting regular monitoring. Both patient and health-system factors play a key role in ensuring continued diabetes monitoring and management. PMID:28585892

Metabolic Biofouling of Glucose Sensors in Vivo: Role of Tissue Microhemorrhages

PubMed Central

Klueh, Ulrike; Liu, Zenghe; Feldman, Ben; Henning, Timothy P; Cho, Brian; Ouyang, Tianmei; Kreutzer, Don

2011-01-01

Objective: Based on our in vitro study that demonstrated the adverse effects of blood clots on glucose sensor function, we hypothesized that in vivo local tissue hemorrhages, induced as a consequence of sensor implantation or sensor movement post-implantation, are responsible for unreliable readings or an unexplained loss of functionality shortly after implantation. Research Design and Methods: To investigate this issue, we utilized real-time continuous monitoring of blood glucose levels in a mouse model. Direct injection of blood at the tissue site of sensor implantation was utilized to mimic sensor-induced local tissue hemorrhages. Results: It was found that blood injections, proximal to the sensor, consistently caused lowered sensor glucose readings, designated temporary signal reduction, in vivo in our mouse model, while injections of plasma or saline did not have this effect. Conclusion: These results support our hypothesis that tissue hemorrhage and resulting blood clots near the sensor can result in lowered local blood glucose concentrations due to metabolism of glucose by the clot. The lowered local blood glucose concentration led to low glucose readings from the still functioning sensor that did not reflect the systemic glucose level. PMID:21722574

Comparision between bed side testing of blood glucose by glucometer vs centralized testing in a tertiary care hospital.

PubMed

Baig, Ayaz; Siddiqui, Imran; Jabbar, Abdul; Azam, Syed Iqbal; Sabir, Salman; Alam, Shahryar; Ghani, Farooq

2007-01-01

To determine the accuracy, turnaround time and cost effectiveness of bedside monitoring of blood glucose levels by non-laboratory health care workers and centralized testing of blood glucose by automated analyzer in a tertiary care hospital. The study was conducted in Section of Chemical Pathology, Department of Pathology and Microbiology and Section of Endocrinology Department of Medicine, Aga Khan University and Hospital Karachi, from April 2005 to March 2006. One hundred and ten patients were included in the study. The blood glucose levels were analyzed on glucometer (Precision Abbott) by finger stick, using Biosensor Technology. At the same time venous blood was obtained to analyze glucose in clinical laboratory on automated analyzer (SYNCHRON CX7) by glucose oxidase method. We observed good correlation between bed side glucometer and laboratory automated analyzer for glucose values between 3.3 mmol/L (60 mg/dl) and 16.7 (300 mg/dl). A significant difference was observed for glucose values less than 3.3 mmol/L (p = 0.002) and glucose values more than 16.67 mmol/l (p = 0.049). Mean Turnaround time for glucometer and automated analyzer were 0.08 hours and 2.49 hours respectively. The cost of glucose testing with glucometer was 48.8% lower than centralized lab based testing. Bedside glucometer testing, though less expensive does not have good accuracy in acutely ill patient with either very high or very low blood glucose levels.

[Designing and implementation of a web-based quality monitoring system for plasma glucose measurement in multicenter population study].

PubMed

Liu, Yong; Wang, Limin; Pang, Richard; Mo, Nanxun; Hu, Yan; Deng, Qian; Hu, Zhaohui

2015-05-01

The aim of this paper is to describe the designing and implementation of a web-based plasma glucose measurement quality monitoring system to assess the analytical quality of plasma glucose measurements in multicenter population study and provide evidence for the future studies. In the chronic non-communicable disease and related factor surveillance in China, a web based quality monitoring system for plasma glucose measurement was established to conduct evaluation on plasma glucose monitoring quality and effectiveness in 302 surveillance centers, including quality control data entry, transmission and feedback. The majority of the surveillance centers met the quality requirements and passed the evaluation of reproducibility and precision of plasma glucose measurement, only a few centers required intensive training and re-assessment. In order to ensure the completeness and reliability of plasma glucose measurement in the surveillance centers, the establishment of web-based plasma glucose measurement quality control system can facilitate the identification of the qualified surveillance centers and evaluation of plasma glucose measurement quality in different regions. Communication and training are important in ensuring plasma glucose measurement quality. It is necessary to further improve this web-based plasma glucose measurement quality monitoring system in the future to reduce the method specific plasma glucose measurement bias.

Continuous glucose monitoring for patients with diabetes: an evidence-based analysis.

PubMed

2011-01-01

To determine the effectiveness and cost-effectiveness of continuous glucose monitoring combined with self-monitoring of blood glucose compared with self-monitoring of blood glucose alone in the management of diabetes. CONDITION AND TARGET POPULATION Diabetes is a chronic metabolic disorder that interferes with the body's ability to produce or effectively use insulin. In 2005, an estimated 816,000 Ontarians had diabetes representing 8.8% of the province's population. Type 1 or juvenile onset diabetes is a life-long disorder that commonly manifests in children and adolescents. It represents about 10% of the total diabetes population and involves immune-mediated destruction of insulin producing cells in the pancreas. The loss of these cells necessitates insulin therapy. Type 2 or "adult-onset" diabetes represents about 90% of the total diabetes population and is marked by a resistance to insulin or insufficient insulin secretion. The risk of developing type 2 diabetes increases with age, obesity and lack of physical activity. Approximately 30% of patients with type 2 diabetes eventually require insulin therapy. Continuous glucose monitors (CGM) measure glucose levels in the interstitial fluid surrounding skin cells. These measurements supplement conventional self monitoring of blood glucose (SMBG) by monitoring the glucose fluctuations continuously over a stipulated period of time, thereby identifying fluctuations that would not be identified with SMBG alone. To use a CGM, a sensor is inserted under the skin to measure glucose in the interstitial fluid. The sensor is wired to a transmitter. The device requires calibration using a capillary blood glucose measurement. Each sensor continuously measures glucose every 5-10 seconds averaging these values every 5 minutes and storing this data in the monitors memory. Depending on the device used, the algorithm in the device can measure glucose over a 3 or 6 day period using one sensor. After the 3 or 6 day period, a new sensor is required. The device is equipped with alarms which warn the patient of impending hypo-or hyperglycemia. Two types of CGM are available: Systems that is stored in a monitor and can be downloaded later.Real time systems that continuously provide the actual glucose concentration on a display. What is the effectiveness and cost-effectiveness of CGM combined with SMBG compared with SMBG alone in the management of diabetes? A literature search was performed on September 15, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 2002 until September 15, 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology. English languageRandomized controlled trials (N>30 patients)Adults or pediatric patients with insulin dependent diabetes (type 1 or 2 or gestational)Studies comparing CGM plus SMBG versus SMBG alone Case studiesStudies that did not compare CGM plus SMBG versus SMBG aloneStudies that did not report statistical analysis of outcomes or data was unextractable Change in glycosylated hemoglobin (HbA1c)Frequency or duration of hypo-or hyperglycemic episodes or euglycemiaAdverse effects Moderate quality evidence that CGM + SMBG: is not more effective than self monitoring of blood glucose (SMBG) alone in the reduction of HbA1c using insulin infusion pumps for Type 1 diabetes.is not more effective than SMBG alone in the reduction of hypoglycemic or severe hypoglycemic events using insulin infusion pumps for Type 1 diabetes.

Effect of Diabetes Mellitus Type 2 on Salivary Glucose – A Systematic Review and Meta-Analysis of Observational Studies

PubMed Central

Mascarenhas, Paulo; Fatela, Bruno; Barahona, Isabel

2014-01-01

Background Early screening of type 2 diabetes mellitus (DM) is essential for improved prognosis and effective delay of clinical complications. However, testing for high glycemia often requires invasive and painful blood testing, limiting its large-scale applicability. We have combined new, unpublished data with published data comparing salivary glucose levels in type 2 DM patients and controls and/or looked at the correlation between salivary glucose and glycemia/HbA1c to systematically review the effectiveness of salivary glucose to estimate glycemia and HbA1c. We further discuss salivary glucose as a biomarker for large-scale screening of diabetes or developing type 2 DM. Methods and Findings We conducted a meta-analysis of peer-reviewed published articles that reported data regarding mean salivary glucose levels and/or correlation between salivary glucose levels and glycemia or HbA1c for type 2 DM and non-diabetic individuals and combined them with our own unpublished results. Our global meta-analysis of standardized mean differences on salivary glucose levels shows an overall large positive effect of type 2 DM over salivary glucose (Hedge's g = 1.37). The global correlation coefficient (r) between salivary glucose and glycemia was large (r = 0.49), with subgroups ranging from medium (r = 0.30 in non-diabetics) to very large (r = 0.67 in diabetics). Meta-analysis of the global correlation between salivary glucose and HbA1c showed an overall association of medium strength (r = 0.37). Conclusions Our systematic review reports an overall meaningful salivary glucose concentration increase in type 2 DM and a significant overall relationship between salivary glucose concentration and associated glycemia/HbA1c values, with the strength of the correlation increasing for higher glycemia/HbA1c values. These results support the potential of salivary glucose levels as a biomarker for type 2 DM, providing a less painful/invasive method for screening type 2 DM, as well as for monitoring blood glucose levels in large cohorts of DM patients. PMID:25025218

Decreased complexity of glucose dynamics in diabetes: evidence from multiscale entropy analysis of continuous glucose monitoring system data.

PubMed

Chen, Jin-Long; Chen, Pin-Fan; Wang, Hung-Ming

2014-07-15

Parameters of glucose dynamics recorded by the continuous glucose monitoring system (CGMS) could help in the control of glycemic fluctuations, which is important in diabetes management. Multiscale entropy (MSE) analysis has recently been developed to measure the complexity of physical and physiological time sequences. A reduced MSE complexity index indicates the increased repetition patterns of the time sequence, and, thus, a decreased complexity in this system. No study has investigated the MSE analysis of glucose dynamics in diabetes. This study was designed to compare the complexity of glucose dynamics between the diabetic patients (n = 17) and the control subjects (n = 13), who were matched for sex, age, and body mass index via MSE analysis using the CGMS data. Compared with the control subjects, the diabetic patients revealed a significant increase (P < 0.001) in the mean (diabetic patients 166.0 ± 10.4 vs. control subjects 93.3 ± 1.5 mg/dl), the standard deviation (51.7 ± 4.3 vs. 11.1 ± 0.5 mg/dl), and the mean amplitude of glycemic excursions (127.0 ± 9.2 vs. 27.7 ± 1.3 mg/dl) of the glucose levels; and a significant decrease (P < 0.001) in the MSE complexity index (5.09 ± 0.23 vs. 7.38 ± 0.28). In conclusion, the complexity of glucose dynamics is decreased in diabetes. This finding implies the reactivity of glucoregulation is impaired in the diabetic patients. Such impairment presenting as an increased regularity of glycemic fluctuating pattern could be detected by MSE analysis. Thus, the MSE complexity index could potentially be used as a biomarker in the monitoring of diabetes.

Periodic Extraction of Interstitial Fluid from the Site of Subcutaneous Insulin Infusion for the Measurement of Glucose: A Novel Single-Port Technique for the Treatment of Type 1 Diabetes Patients

PubMed Central

Lindpointner, Stefan; Korsatko, Stefan; Tutkur, Dina; Bodenlenz, Manfred; Pieber, Thomas R.

2013-01-01

Abstract Background Treatment of type 1 diabetes patients could be simplified if the site of subcutaneous insulin infusion could also be used for the measurement of glucose. This study aimed to assess the agreement between blood glucose concentrations and glucose levels in the interstitial fluid (ISF) that is extracted from the insulin infusion site during periodic short-term interruptions of continuous subcutaneous insulin infusion (CSII). Subjects and Methods A perforated cannula (24 gauge) was inserted into subcutaneous adipose tissue of C-peptide-negative type 1 diabetes subjects (n=13) and used alternately to infuse rapid-acting insulin (100 U/mL) and to extract ISF glucose during a fasting period and after ingestion of a standard oral glucose load (75 g). Results Although periodically interrupted for extracting glucose (every hour for approximately 10 min), insulin infusion with the cannula was adequate to achieve euglycemia during fasting and to restore euglycemia after glucose ingestion. Furthermore, the ISF-derived estimates of plasma glucose levels agreed well with plasma glucose concentrations. Correlation coefficient and median absolute relative difference values were found to be 0.95 and 8.0%, respectively. Error grid analysis showed 99.0% of all ISF glucose values within clinically acceptable Zones A and B (83.5% Zone A, 15.5% Zone B). Conclusions Results show that ISF glucose concentrations measured at the insulin infusion site during periodic short-term interruptions of CSII closely reflect blood glucose levels, thus suggesting that glucose monitoring and insulin delivery may be performed alternately at the same tissue site. A single-port device of this type could be used to simplify and improve glucose management in diabetes. PMID:23126579

Wireless connection of continuous glucose monitoring system to the electronic patient record

NASA Astrophysics Data System (ADS)

Murakami, Alexandre; Gutierrez, Marco A.; Lage, Silvia G.; Rebelo, Marina S.; Granja, Luiz A. R.; Ramires, Jose A. F.

2005-04-01

The control of blood sugar level (BSL) at near-normal levels has been documented to reduce both acute and chronic complications of diabetes mellitus. Recent studies suggested, the reduction of mortality in a surgical intensive care unit (ICU), when the BSL are maintained at normal levels. Despite of the benefits appointed by these and others clinical studies, the strict BSL control in critically ill patients suffers from some difficulties: a) medical staff need to measure and control the patient"s BSL using blood sample at least every hour. This is a complex and time consuming task; b) the inaccuracy of standard capillary glucose monitoring (fingerstick) in hypotensive patients and, if frequently used to sample arterial or venous blood, may lead to excess phlebotomy; c) there is no validated procedure for continuously monitoring of BSL levels. This study used the MiniMed CGMS in ill patients at ICU to send, in real-time, BSL values to a Web-Based Electronic Patient Record. The BSL values are parsed and delivered through a wireless network as an HL7 message. The HL7 messages with BSL values are collected, stored into the Electronic Patient Record and presented into a bed-side monitor at the ICU together with other relevant patient information.

Remote Monitoring and Consultation of Inpatient Populations with Diabetes.

PubMed

Rushakoff, Robert J; Rushakoff, Joshua A; Kornberg, Zachary; MacMaster, Heidemarie Windham; Shah, Arti D

2017-09-01

Inpatient hyperglycemia is common and is linked to increased morbidity and mortality. We review current and innovative ways diabetes specialists consult in the management of inpatient diabetes. With electronic medical records (EMRs), remote monitoring and intervention may improve the management of inpatient hyperglycemia. Automated reports allow monitoring of glucose levels and allow diabetes teams to intervene through formal or remote consultation. Following a 2-year transition of our complex paper-based insulin order sets to be EMR based, we leveraged this change by developing new daily glycemic reports and a virtual glucose management service (vGMS). Based on a daily report identifying patients with two or more glucoses over 225 mg/dl and/or a glucose <70 mg/dl in the past 24 h, a vGMS note with management recommendations was placed in the chart. Following the introduction of the vGMS, the proportion of hyperglycemic patients decreased 39% from a baseline of 6.5 per 100 patient-days to 4.0 per 100 patient-days The hypoglycemia proportion decreased by 36%. Ninety-nine percent of surveyed medical and surgical residents said the vGMS was both important and helpful.

Effect of combined application insulin and insulin detemir on continous glucose monitor in children with type 1 diabetes mellitus.

PubMed

Chen, Xiao-Yun; Dong, Qing; Li, Gui-Mei

2015-01-01

Insulin detemir is a soluble long-acting human insulin analogue at neutral pH with a unique mechanism of action, which could strengthen the effects of insulin. This study aims to explore the effects of insulin combined with insulin detemir on the continous glucose in children with type 1 diabetes mellitus. In this study, 150 patients with type 1 diabetes enrolled were included and randomly divided into 3 groups: insulin group (group A), insulin detemir group (group B) and insulin combined with insulin detemir group (group C). Each subject underwent 72 h of continuous glucose monitoring (CGM). MAGE, HbA1c and Noctumal Hypoglycemia levels were examined by using the ELISA kits. The body weight changes were also detected in this study. The results indicated that the information including age, body weight, disease duration and glucose level and HbA1c percentage on the start time point among three groups indicated no statistical differences. Insulin combined with insulin detemir decrease MAGE and HbA1c level in Group C compared to Group A and Group A (P < 0.05). Insulin combined with insulin detemir decreas noctumal hypoglycemia levels and body weight changes (P < 0.05). In conclusion, this study confirmed efficacy of insulin detemir by demonstrating non-inferiority of insulin detemir compared with insulin with respect to HbA1c, with an improved safety profile including significantly fewer hypoglycaemic episodes and less undesirable weight gain in children.

The effectiveness of continuous subcutaneous insulin pumps with continuous glucose monitoring in outpatient adolescents with type 1 diabetes: A systematic review.

PubMed

Matsuda, Erin; Brennan, Patricia

The review question is: Are metabolic outcomes improved in outpatient adolescents (aged 13 to 19 years) with type 1 diabetes on a Continuous Subcutaneous Insulin Infusion (CSII) when continuous glucose monitoring is used, compared to self-glucose monitoring alone? Type 1 diabetes is the most common childhood paediatric disease, characterised by impairment of insulin producing βeta-cells in the pancreas. Internationally, there is variation in the incidence of type 1 diabetes in paediatric patients. According to the Center for Disease Control and Prevention (CDC) and the SEARCH for Diabetes in Youth Study Group, the overall incidence rate of this autoimmune disease is 24.3/100,000 in those 19 years of age . Annually, more than 15,000 children and adolescents are diagnosed in the United States (US) . From 1990 to 1999, the World Health Organization (WHO) launched the Multinational Project for Childhood Diabetes (DIAMOND), which was tasked with assessing type 1 diabetes in those 14 years or younger worldwide . Finland was discovered to have the highest age-adjusted incidence at 40.9 cases per 100,000/year. The lowest age-adjusted incidence is in China and Venezuela at 0.1 cases per 100,000/year. Globally, the largest increase in incidence is in those aged 10 to 14 years . This systematic review will focus on adolescent patients with type 1 diabetes, aged 13 to 19 years who manage their diabetes with an insulin pump.Patients with type 1 diabetes mellitus typically present with a history of polydipsia, polyuria, polyphagia, and weight loss . Initial findings include hyperglycemia, glycosuria, and ketones in the blood or urine . In 2009, the International Expert Committee deemed a haemoglobin A1C (glycosylated haemoglobin) of 6.5% or higher to be the standard for diagnosis . The American Diabetes Association (ADA) as well as the International Diabetes Federation and the European Association Study of Diabetes (EASD) accept this measure as the diagnostic tool for diabetes. Haemoglobin A1C is the most commonly used measurement for patients with type 1 diabetes . It refers to the measurement of the amount of glucose bound to haemoglobin. It is an average of blood glucose levels for the last 120 days, which is consistent with the average life span of a red blood cell (RBC).Compensation for the lack of insulin-secreting βeta-cells is accomplished through administration of insulin. For adolescents, insulin dosing is based on pubescent status, age, weight, activity level, and amount of carbohydrates consumed . Insulin administration, carbohydrate counting, and correction of hyperglycemia are necessary for maintaining glycemic control. Insulin can be administered through multiple daily injections (MDI) of rapid, intermediate and long-acting insulin .Another form of insulin delivery is the Continuous Subcutaneous Insulin Infusion (CSII), also known as an insulin pump, which is designed to meet physiological requirements through programmable basal rates and bolus doses . CSII's utilise rapid-acting insulin and establish a basal rate, which replaces the need for long-acting insulin. Bolus dosing is accomplished through adjusting the pump and is utilised to account for nutritional intake as well as hyperglycemia correction. Adjustments are also made for physical activity and exercise, as this can affect glucose levels . All patients considered in this systematic review will be utilising insulin pumps.In 2006, the United States had more than 35,000 patients, under the age of 21 years, receiving insulin therapy through an insulin pump . In Europe, the percentage of people with type 1 diabetes utilising a CSII is lower, potentially due to variation in health care coverage . There are various forms of insulin pumps, all with similar capabilities including a dose calculator for high blood glucose correction and carbohydrate ratios, programming software, and several other features . Software and programming is specific to each manufacturer. Basal rate abilities vary in each model from 0.05 units/hour to 30 units/hour . Information from the pump can be uploaded to online registries allowing providers to review trends and usage. It is imperative the information is reviewed concurrently with glucose monitoring results in order to ensure appropriate dosing and treatment .The intervention considered in this systematic review is the use of continuous glucose monitoring (CGM) in conjunction with a CSII. CGM utilises a sensor placed in the interstitial subcutaneous tissue, which then measures glucose levels. This is accomplished with "electrochemical sensors that use glucose oxidase and measure an electric current generated when glucose reacts with oxygen. The sensors are coated with a specialised membrane to make them biocompatible" . The CGM has programmable high and low levels to alert the user when the limit is being reached. Information regarding continuous glucose levels can then be downloaded and reviewed. Based on the report, providers, patients, and caregivers may assess trends and consider changing basal rates or bolus doses .CGM sensors currently do not offer a closed-loop solution. The user must enter insulin dosing information into the pump, taking into account the present glucose level and duration of action of the insulin. Currently, CGMs are regarded as a supplemental method for assessing the effectiveness of glucose control. Existing studies are underway to improve accuracy and communication between the sensor and insulin pump with the goal to develop an artificial pancreas . Currently, CGM sensors must be calibrated with a glucometer, as specified by the manufacturer .The comparison for this review is the standard of care, self-glucose monitoring (SGM), in patients with insulin pumps . SGM is accomplished with a glucometer and blood sample typically obtained from a finger prick. The Diabetes Control and Complications Trial (DCCT) demonstrated frequency of monitoring improves glycemic control and decreases the risk of comorbidity . Data from this significant study continues to contribute to current diabetes management. According to the ADA, children and adolescents should monitor their blood glucose at least three or more times per day. Blood glucose data is utilised to calculate appropriate insulin doses. Similar to the CGM, information from the glucometers can be downloaded for assessment of results and trends. However, the result is dependent on the action of the patient to obtain the sample and only represents a specific moment in time whereas the CGM sensor continuously tracks the blood glucose level. Depending on the model, CGM can provide glucose levels every one to ten minutes. The sensor may last for up to 72 hours and results are available in real time .This systematic review will address two metabolic outcomes: a decrease in the number of hypoglycemic episodes and a haemoglobin A1C level <7.5%. These outcomes were chosen due to their significance as indicators in the management of type 1 diabetes. Glucose levels should be between 90 mg/dL and 130 mg/dL (5.0mmol/l and 7.2mmol/l) before meals and between 90 mg/dL and 150 mg/dL at night (5.0mmmol/l and 8.3mmol/l) . Optimal care of an adolescent with type 1 diabetes mellitus is to safely maintain glycemic control and avoid hypoglycemia.Haemoglobin A1C is an indicator of how well the disease is being managed and should be evaluated every three months. McCulloch recommends the haemoglobin A1C level should be compared to approximately 50 recent blood glucose readings to ensure the accuracy of patient SGM . The reliability and validity of this test is based on the evidence discovered by the DCCT demonstrating those with lower haemoglobin A1C levels have fewer complications . The target A1C for adolescents, aged 13 to 19 years of age, is <7.5% . This is consistent with the National Institute of Clinical Excellence (NICE) and diabetes management guidelines of the Australasian Paediatric Endocrine Group for the Department of Health and Ageing .An initial search for a systematic review regarding insulin pumps in adolescents with type 1 diabetes mellitus and concurrent use of CGM was conducted in the Joanna Briggs Institute Library of Systematic Reviews, Cochrane Database of Systematic Reviews, and PubMed. No systematic reviews were found.

A Review of Emerging Technologies for the Management of Diabetes Mellitus.

PubMed

Zarkogianni, Konstantia; Litsa, Eleni; Mitsis, Konstantinos; Wu, Po-Yen; Kaddi, Chanchala D; Cheng, Chih-Wen; Wang, May D; Nikita, Konstantina S

2015-12-01

High prevalence of diabetes mellitus (DM) along with the poor health outcomes and the escalated costs of treatment and care poses the need to focus on prevention, early detection and improved management of the disease. The aim of this paper is to present and discuss the latest accomplishments in sensors for glucose and lifestyle monitoring along with clinical decision support systems (CDSSs) facilitating self-disease management and supporting healthcare professionals in decision making. A critical literature review analysis is conducted focusing on advances in: 1) sensors for physiological and lifestyle monitoring, 2) models and molecular biomarkers for predicting the onset and assessing the progress of DM, and 3) modeling and control methods for regulating glucose levels. Glucose and lifestyle sensing technologies are continuously evolving with current research focusing on the development of noninvasive sensors for accurate glucose monitoring. A wide range of modeling, classification, clustering, and control approaches have been deployed for the development of the CDSS for diabetes management. Sophisticated multiscale, multilevel modeling frameworks taking into account information from behavioral down to molecular level are necessary to reveal correlations and patterns indicating the onset and evolution of DM. Integration of data originating from sensor-based systems and electronic health records combined with smart data analytics methods and powerful user centered approaches enable the shift toward preventive, predictive, personalized, and participatory diabetes care. The potential of sensing and predictive modeling approaches toward improving diabetes management is highlighted and related challenges are identified.

A Review of Emerging Technologies for the Management of Diabetes Mellitus

PubMed Central

Zarkogianni, Konstantia; Litsa, Eleni; Mitsis, Konstantinos; Wu, Po-Yen; Kaddi, Chanchala D.; Cheng, Chih-Wen; Wang, May D.; Nikita, Konstantina S.

2016-01-01

Objective High prevalence of diabetes mellitus (DM) along with the poor health outcomes and the escalated costs of treatment and care poses the need to focus on prevention, early detection and improved management of the disease. The aim of this paper is to present and discuss the latest accomplishments in sensors for glucose and lifestyle monitoring along with clinical decision support systems (CDSSs) facilitating self-disease management and supporting healthcare professionals in decision making. Methods A critical literature review analysis is conducted focusing on advances in: 1) sensors for physiological and lifestyle monitoring, 2) models and molecular biomarkers for predicting the onset and assessing the progress of DM, and 3) modeling and control methods for regulating glucose levels. Results Glucose and lifestyle sensing technologies are continuously evolving with current research focusing on the development of noninvasive sensors for accurate glucose monitoring. A wide range of modeling, classification, clustering, and control approaches have been deployed for the development of the CDSS for diabetes management. Sophisticated multiscale, multilevel modeling frameworks taking into account information from behavioral down to molecular level are necessary to reveal correlations and patterns indicating the onset and evolution of DM. Conclusion Integration of data originating from sensor-based systems and electronic health records combined with smart data analytics methods and powerful user centered approaches enable the shift toward preventive, predictive, personalized, and participatory diabetes care. Significance The potential of sensing and predictive modeling approaches toward improving diabetes management is highlighted and related challenges are identified. PMID:26292334

Accuracy of a new real-time continuous glucose monitoring algorithm.

PubMed

Keenan, D Barry; Cartaya, Raymond; Mastrototaro, John J

2010-01-01

Through minimally invasive sensor-based continuous glucose monitoring (CGM), individuals can manage their blood glucose (BG) levels more aggressively, thereby improving their hemoglobin A1c level, while reducing the risk of hypoglycemia. Tighter glycemic control through CGM, however, requires an accurate glucose sensor and calibration algorithm with increased performance at lower BG levels. Sensor and BG measurements for 72 adult and adolescent subjects were obtained during the course of a 26-week multicenter study evaluating the efficacy of the Paradigm REAL-Time (PRT) sensor-augmented pump system (Medtronic Diabetes, Northridge, CA) in an outpatient setting. Subjects in the study arm performed at least four daily finger stick measurements. A retrospective analysis of the data set was performed to evaluate a new calibration algorithm utilized in the Paradigm Veo insulin pump (Medtronic Diabetes) and to compare these results to performance metrics calculated for the PRT. A total of N = 7193 PRT sensor downloads for 3 days of use, as well as 90,472 temporally and nonuniformly paired data points (sensor and meter values), were evaluated, with 5841 hypoglycemic and 15,851 hyperglycemic events detected through finger stick measurements. The Veo calibration algorithm decreased the overall mean absolute relative difference by greater than 0.25 to 15.89%, with hypoglycemia sensitivity increased from 54.9% in the PRT to 82.3% in the Veo (90.5% with predictive alerts); however, hyperglycemia sensitivity was decreased only marginally from 86% in the PRT to 81.7% in the Veo. The Veo calibration algorithm, with sensor error reduced significantly in the 40- to 120-mg/dl range, improves hypoglycemia detection, while retaining accuracy at high glucose levels. 2010 Diabetes Technology Society.

Managing diabetes at high altitude: personal experience with support from a Multidisciplinary Physical Activity and Diabetes Clinic.

PubMed

Malcolm, Gary; Rilstone, Sian; Sivasubramaniyam, Sivasujan; Jairam, Carol; Chew, Stephen; Oliver, Nick; Hill, Neil E

2017-01-01

Physical activity is important for well-being but can be challenging for people with diabetes. Data informing support of specialist activities such as climbing and high-altitude trekking are limited. A 42-year-old man with type 1 diabetes (duration 30 years) attended a Multidisciplinary Physical Activity and Diabetes Clinic planning to climb Mont Blanc during the summer and trek to Everest Base Camp in the autumn. His aims were to complete these adventures without his diabetes impacting on their success. We report the information provided that enabled him to safely facilitate his objectives, in particular, the requirement for frequent checking of blood glucose levels, the effects of altitude on insulin dose requirements, and recognition that acute mountain sickness may mimic the symptoms of hypoglycaemia and vice versa. Real-time continuous glucose monitoring was made available for his treks. The effects of high altitude on blood glucose results and glycaemic variability while treated on multiple daily injections of insulin are reported. In addition, we present a first-person account of his experience and lessons learnt from managing diabetes at high altitude. A dedicated Multidisciplinary Physical Activity and Diabetes Clinic delivering individualised, evidence-based, patient-focused advice on the effects of altitude on blood glucose levels, and provision of real-time continuous glucose monitoring enabled uneventful completion of a trek to Everest Base Camp in a person with type 1 diabetes.

The optimal blood glucose level for critically ill adult patients.

PubMed

Lv, Shaoning; Ross, Paul; Tori, Kathleen

2017-09-01

Glycaemic control is recognized as one of the important aspects in managing critically ill patients. Both hyperglycaemia and hypoglycaemia independently increase the risk of patient mortality. Hence, the identification of optimal glycaemic control is of paramount importance in the management of critically ill patients. The aim of this literature review is to examine the current status of glycaemic control in critically ill adult patients. This literature review will focus on randomized controlled trials comparing intensive insulin therapy to conventional insulin therapy, with an objective to identify optimal blood glucose level targets for critically ill adult patients. A literature review was conducted to identify large randomized controlled trials for the optimal targeted blood glucose level for critically ill adult patients published since 2000. A total of eight studies fulfilled the selection criteria of this review. With current human and technology resources, the results of the studies support commencing glycaemic control once the blood glucose level of critically ill patients reaches 10 mmol/L and maintaining this level between 8 mmol/L and 10 mmol/L. This literature review provides a recommendation for targeting the optimal blood glucose level for critically ill patients within moderate blood glucose level target range (8-10 mmol/L). The need for uniformed glucometrics for unbiased reporting and further research for optimal blood glucose target is required, especially in light of new technological advancements in closed-loop insulin delivery and monitoring devices. This literature review has revealed a need to call for consensus in the measurement and reporting of glycaemic control using standardized glucometrics. © 2017 British Association of Critical Care Nurses.

DreamTel; Diabetes risk evaluation and management tele-monitoring study protocol

PubMed Central

Tobe, Sheldon W; Wentworth, Joan; Ironstand, Laurie; Hartman, Susan; Hoppe, Jackie; Whiting, Judi; Kennedy, Janice; McAllister, Colin; Kiss, Alex; Perkins, Nancy; Vincent, Lloyd; Pylypchuk, George; Lewanczuk, Richard Z

2009-01-01

Background The rising prevalence of type 2 diabetes underlines the importance of secondary strategies for the prevention of target organ damage. While access to diabetes education centers and diabetes intensification management has been shown to improve blood glucose control, these services are not available to all that require them, particularly in rural and northern areas. The provision of these services through the Home Care team is an advance that can overcome these barriers. Transfer of blood glucose data electronically from the home to the health care provider may improve diabetes management. Methods and design The study population will consist of patients with type 2 diabetes with uncontrolled A1c levels living on reserve in the Battlefords region of Saskatchewan, Canada. This pilot study will take place over three phases. In the first phase over three months the impact of the introduction of the Bluetooth enabled glucose monitor will be assessed. In the second phase over three months, the development of guidelines based treatment algorithms for diabetes intensification will be completed. In the third phase lasting 18 months, study subjects will have diabetes intensification according to the algorithms developed. Discussion The first phase will determine if the use of the Bluetooth enabled blood glucose devices which can transmit results electronically will lead to changes in A1c levels. It will also determine the feasibility of recruiting subjects to use this technology. The rest of the Diabetes Risk Evaluation and Management Tele-monitoring (DreamTel) study will determine if the delivery of a diabetes intensification management program by the Home Care team supported by the Bluetooth enabled glucose meters leads to improvements in diabetes management. Trial Registration Protocol NCT00325624 PMID:19426530

DreamTel; Diabetes risk evaluation and management tele-monitoring study protocol.

PubMed

Tobe, Sheldon W; Wentworth, Joan; Ironstand, Laurie; Hartman, Susan; Hoppe, Jackie; Whiting, Judi; Kennedy, Janice; McAllister, Colin; Kiss, Alex; Perkins, Nancy; Vincent, Lloyd; Pylypchuk, George; Lewanczuk, Richard Z

2009-05-09

The rising prevalence of type 2 diabetes underlines the importance of secondary strategies for the prevention of target organ damage. While access to diabetes education centers and diabetes intensification management has been shown to improve blood glucose control, these services are not available to all that require them, particularly in rural and northern areas. The provision of these services through the Home Care team is an advance that can overcome these barriers. Transfer of blood glucose data electronically from the home to the health care provider may improve diabetes management. The study population will consist of patients with type 2 diabetes with uncontrolled A1c levels living on reserve in the Battlefords region of Saskatchewan, Canada. This pilot study will take place over three phases. In the first phase over three months the impact of the introduction of the Bluetooth enabled glucose monitor will be assessed. In the second phase over three months, the development of guidelines based treatment algorithms for diabetes intensification will be completed. In the third phase lasting 18 months, study subjects will have diabetes intensification according to the algorithms developed. The first phase will determine if the use of the Bluetooth enabled blood glucose devices which can transmit results electronically will lead to changes in A1c levels. It will also determine the feasibility of recruiting subjects to use this technology. The rest of the Diabetes Risk Evaluation and Management Tele-monitoring (DreamTel) study will determine if the delivery of a diabetes intensification management program by the Home Care team supported by the Bluetooth enabled glucose meters leads to improvements in diabetes management. Protocol NCT00325624.

Optical coherence tomography technique for noninvasive blood glucose monitoring: phantom, animal, and human studies

NASA Astrophysics Data System (ADS)

Larin, Kirill V.; Ashitkov, Taras V.; Larina, Irina V.; Petrova, Irina Y.; Eledrisi, Mohsen S.; Motamedi, Massoud; Esenaliev, Rinat O.

2002-06-01

Continuous noninvasive monitoring of blood glucose concentration can improve management of Diabetes Mellitus, reduce mortality, and considerably improve quality of life of diabetic patients. Recently, we proposed to use the OCT technique for noninvasive glucose monitoring. In this paper, we tested noninvasive blood glucose monitoring with the OCT technique in phantoms, animals, and human subjects. An OCT system with the wavelength of 1300 nm was used in our experiments. Phantom studies performed on aqueous suspensions of polystyrene microspheres and milk showed 3.2% decrease of exponential slope of OCT signals when glucose concentration increased from 0 to 100 mM. Theoretical calculations based on the Mie theory of scattering support the results obtained in phantoms. Bolus glucose injections and glucose clamping experiments were performed in animals (New Zealand rabbits and Yucatan micropigs). Good correlation between changes in the OCT signal slope and actual blood glucose concentration were observed in these experiments. First studies were performed in healthy human subjects (using oral glucose tolerance tests). Dependence of the slope of the OCT signals on the actual blood glucose concentration was similar to that obtained in animal studies. Our studies suggest that the OCT technique can potentially be used for noninvasive blood glucose monitoring.

Recommending blood glucose monitors, a pharmacy perspective.

PubMed

Carter, Alan

2007-03-01

Selection of what blood glucose monitoring system to utilize has become an issue for physicians, diabetes educators, pharmacists, and patients. The field of competing makes and models of blood glucose monitoring systems has become crowded, with manufacturers touting improvements in accuracy, ease of use/alternate site options, stored results capacity, software evaluation tools, and/or price point. Personal interviews of 12 pharmacists from community and academic practice settings about monitor preference, as well as results from a national survey of pharmacist recommendations, were compared to actual wholesale sales data to estimate the impact of such recommendations on final monitor selection by the patient. Accu-Chek monitors were recommended 34.65% of the time and represented 28.58% of sales, with a success rate of 82.48% of being the monitor selected. OneTouch monitors had 27.72% of recommendations but represented 31.43% of sales, indicating possible patient brand loyalty or formulary preference for that product. FreeStyle(R) monitors came in third for pharmacist recommendations and were selected by the patient 61.68% of the time when recommended. The category of "other monitor" choices was selected 60.89% of the time by patients given those suggestions. Included in the "other monitor" category was the new disposable monitor marketed as the Sidekick. Based on sales data provided, the Sidekick made up 2.87% of "other monitor" category sales, representing 68% of the "other monitor" segment. While patients frequently follow pharmacist monitoring system suggestions, the ultimate deciding factor is most often the final out-of-pocket cost to the patient. As a result, cost of supplies often becomes the most important determining factor in final monitor selection at the patient level. If the patient cannot afford to perform the recommended daily testing intervals, all other determining factors and suggestions become moot.

SELF BLOOD GLUCOSE MONITORING UNDERESTIMATES HYPERGLYCEMIA AND HYPOGLYCEMIA AS COMPARED TO CONTINUOUS GLUCOSE MONITORING IN TYPE 1 AND TYPE 2 DIABETES.

PubMed

Mangrola, Devna; Cox, Christine; Furman, Arianne S; Krishnan, Sridevi; Karakas, Sidika E

2018-01-01

When glucose records from self blood glucose monitoring (SBGM) do not reflect estimated average glucose from glycosylated hemoglobin (HgBA1) or when patients' clinical symptoms are not explained by their SBGM records, clinical management of diabetes becomes a challenge. Our objective was to determine the magnitude of differences in glucose values reported by SBGM versus those documented by continuous glucose monitoring (CGM). The CGM was conducted by a clinical diabetes educator (CDE)/registered nurse by the clinic protocol, using the Medtronic iPRO2 ™ system. Patients continued SBGM and managed their diabetes without any change. Data from 4 full days were obtained, and relevant clinical information was recorded. De-identified data sets were provided to the investigators. Data from 61 patients, 27 with type 1 diabetes (T1DM) and 34 with T2DM were analyzed. The lowest, highest, and average glucose recorded by SBGM were compared to the corresponding values from CGM. The lowest glucose values reported by SBGM were approximately 25 mg/dL higher in both T1DM ( P = .0232) and T2DM ( P = .0003). The highest glucose values by SBGM were approximately 30 mg/dL lower in T1DM ( P = .0005) and 55 mg/dL lower in T2DM ( P<.0001). HgBA1c correlated with the highest and average glucose by SBGM and CGM. The lowest glucose values were seen most frequently during sleep and before breakfast; the highest were seen during the evening and postprandially. SBGM accurately estimates the average glucose but underestimates glucose excursions. CGM uncovers glucose patterns that common SBGM patterns cannot. CDE = certified diabetes educator; CGM = continuous glucose monitoring; HgBA1c = glycosylated hemoglobin; MAD = mean absolute difference; SBGM = self blood glucose monitoring; T1DM = type 1 diabetes; T2DM = type 2 diabetes.

Monitoring blood glucose levels in female mink during the reproductive cycle: 1. Prevention of hyperglycemia during the nursing period

PubMed Central

Hynes, Amber M.J.; Rouvinen-Watt, Kirsti

2007-01-01

Nursing sickness, the largest cause of death in female adult mink, is a metabolic disorder characterized by hyperglycemia. The impacts of body condition, dietary supplements, and reproductive status on the blood glucose concentration in female mink during the reproductive cycle were investigated. Mink dams on 3 farms were assigned to receive either herring oil (HerO) or chromium picolinate (CrPic) or to be in a control group, receiving only the basal diet, for 6 wk at the onset of lactation. Hyperglycemia was observed throughout the reproductive cycle. Significant differences in blood glucose levels were observed between farms, emphasizing the importance of herd genetics and of animal management and feeding practices in glycemic regulation. Female mink exhibiting hyperglycemia early in the reproductive cycle tended to remain hyperglycemic and to have poorer health and fewer kits. Glucose levels > 7 mmol/L can be considered critical in this regard. Supplementing the diet with CrPic reduced the blood glucose concentration. Results from this study suggest that a diet containing high-quality n-3 polyunsaturated fatty acids, high levels of carbohydrate, and CrPic supplementation may help the nursing mink dam maintain a normal blood glucose concentration during lactation. PMID:17955897

Glucose biosensors with enzyme entrapped in polymer coating.

PubMed

Yang, S; Atanasov, P; Wilkins, E

1995-01-01

The pursuit of reliable biosensors for measuring glucose levels has been ongoing for decades. Their importance lies partly in the development of the implantable artificial pancrease, which can be used to deliver insulin to diabetics without the need to test glucose levels externally, with automatic delivery based on physiologic demand. Glucose sensors can also be used in short-term monitoring of glucose levels in hospitals and clinical laboratories. Three types of glucose biosensors were studied. All were based on a two-electrode system: an insulated platinum wire as a hydrogen peroxide electrode, and a silver wire twisted around the platinum wire as both a reference and a counter electrode. Each was coated with the enzyme glucose oxidase entrapped in a polymer matrix of cellulose acetate (CA) or poly 2-hydroxyethyl methacrylate (HEMA), then dip-coated by an additional polymer coating of polyvinylchloride (PVC), polyurethane (PU), or HEMA. The experiments were designed mainly to study the effectiveness of polymer coatings as diffusion-limiting membranes. The effect of each coating on the linear response to glucose concentration was examined. It was shown that additional (multiple) coatings can increase the linearity of the sensor response. The best results were obtained when the sensor was PVC-dip-coated three times. This preparation had a linear response up to 600 mg/DL glucose concentration. The sensors coated with PU and HEMA have linearity up to 280 and 240 mg/DL glucose concentrations, respectively. It was also shown that the coatings reduce interference from certain body chemicals.

Carbohydrates – Guidelines on Parenteral Nutrition, Chapter 5

PubMed Central

Bolder, U.; Ebener, C.; Hauner, H.; Jauch, K. W.; Kreymann, G.; Ockenga, J.; Traeger, K.

2009-01-01

The main role of carbohydrates in the human body is to provide energy. Carbohydrates should always be infused with PN (parenteral nutrition) in combination with amino acids and lipid emulsions to improve nitrogen balance. Glucose should be provided as a standard carbohydrate for PN, whereas the use of xylite is not generally recommended. Fructose solutions should not be used for PN. Approximately 60% of non-protein energy should be supplied as glucose with an intake of 3.0–3.5 g/kg body weight/day (2.1–2.4 mg/kg body weight/min). In patients with a high risk of hyperglycaemia (critically ill, diabetes, sepsis, or steroid therapy) an lower initial carbohydrate infusion rate of 1–2 g/kg body weight/day is recommended to achieve normoglycaemia. One should aim at reaching a blood glucose level of 80–110 mg/dL, and at least a glucose level <145 mg/dL should be achieved to reduce morbidity and mortality. Hyperglycaemia may require addition of an insulin infusion or a reduction (2.0–3.0 g/kg body weight/day) or even a temporary interruption of glucose infusion. Close monitoring of blood glucose levels is highly important. PMID:20049080

Socioeconomic disparities in type 2 diabetes mellitus prevalence and self-management behaviors in rural southwest China.

PubMed

Le, Cai; Rong, Su; Dingyun, You; Wenlong, Cui

2016-11-01

This study examines how socioeconomic factors are associated with prevalence and self-management of diabetes among ethnic minority groups in the rural Yunnan province, which has the most ethnic minority groups per province in southwest China. A cross-sectional survey was carried out in 2014 in a rural southwest population consisting of 5532 consenting individuals aged ⩾35years. Information about participants' demographic characteristics, as well as diabetes diagnosis, treatment, and self-management behaviors, were obtained using a standard questionnaire. Fasting blood sugar levels were recorded for each individual. A socioeconomic position (SEP) index was constructed using principal component analysis. The age-standardized prevalence of diabetes in the study population was 4.8%. In persons with diabetes, 23.1% regularly self-monitored blood glucose, 43.2% adhered to taking prescribed anti-diabetic drugs or insulin injections, and 63.1% took at least one measure to control blood glucose. Individual educational level was found to be negatively associated with the prevalence of diabetes, whereas individuals with greater household assets and higher SEP were more likely to be suffered from diabetes. Persons with diabetes with greater household assets, higher level of education, and higher SEP had a greater probability of regularly self-monitoring blood glucose, compliance to prescribed medicines, and taking measures to control diabetes. Access to medical services was positively associated with regularly self-monitoring blood glucose and compliance to prescribed medicines. Socioeconomic disparities in diabetes prevalence and self-management do exist. Future interventions to further control diabetes and improve diabetes management must be tailored to address socioeconomic factors. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Tighter accuracy standards within point-of-care blood glucose monitoring: how six commonly used systems compare.

PubMed

Robinson, Charlotte S; Sharp, Patrick

2012-05-01

Blood glucose monitoring systems (BGMS) are used in the hospital environment to manage blood glucose levels in patients at the bedside. The International Organization for Standardization (ISO) 15197:2003 standard is currently used by regulatory bodies as a minimum requirement for the performance of BGMS, specific to self-testing. There are calls for the tightening of accuracy requirements and implementation of a standard specifically for point-of-care (POC) BGMS. The accuracy of six commonly used BGMS was assessed in a clinical setting, with 108 patients' finger stick capillary samples. Using the accuracy criteria from the existing standard and a range of tightened accuracy criteria, system performance was compared. Other contributors to system performance have been measured, including hematocrit sensitivity and meter error rates encountered in the clinical setting. Five of the six BGMS evaluated met current accuracy criteria within the ISO 15197 standard. Only the Optium Xceed system had >95% of all readings within a tightened criteria of ±12.5% from the reference at glucose levels ≥72 mg/dl (4 mmol/liter) and ±9 mg/dl (0.5 mmol/liter) at glucose levels <72 mg/dl (4 mmol/liter). The Nova StatStrip Xpress had the greatest number of error messages observed; Optium Xceed the least. OneTouch Ultra2, Nova StatStrip Xpress, Accu-Chek Performa, and Contour TS products were all significantly influenced by blood hematocrit levels. From evidence obtained during this clinical evaluation, the Optium Xceed system is most likely to meet future anticipated accuracy standards for POC BGMS. In this clinical study, the results demonstrated the Optium Xceed product to have the highest level of accuracy, to have the lowest occurrence of error messages, and to be least influenced by blood hematocrit levels. © 2012 Diabetes Technology Society.

Recent Advances in Nanotechnology-Based Diagnosis and Treatments of Diabetes.

PubMed

Rao, Pasupuleti Visweswara; Gan, Siew Hua

2015-01-01

Nanotechnology is a field encompassing nanostructures, nanomaterials and nanoparticles, which are of increasing importance to researchers and industrial players alike. Nanotechnology addresses the construction and consumption of substances and devices on the nanometer scale. Nanomedicine is a new field that combines nanotechnology with medicine to boost human health care. Nanomedicine is an interdisciplinary field that includes various areas of biology, chemistry, physics and engineering. The most important problems related to diabetes management, such as self-monitoring of blood glucose levels and insulin injections, can now be conquered due to progress in nanomedicine, which offers glucose nanosensors, the layer-by-layer technique, carbon nanotubes, quantum dots, oral insulins, microspheres, artificial pancreases and nanopumps. In this review, the key methodological and scientific characteristics of nanomedicine related to diabetes treatment, glucose monitoring and insulin administration are discussed.

The use of an Energy Monitor in the management of diabetes: a pilot study.

PubMed

Voon, Rudi; Celler, Branko G; Lovell, Nigel H

2009-02-01

This study evaluated the use of an accelerometer-based device in helping to manage blood glucose levels (BGLs) in people with diabetes mellitus. Five people with diabetes were given a triaxial accelerometer-based device (Energy Monitor) that measured energy levels associated with activities of daily living. For 3 months, they were required to wear the device and to continue with their usual diabetes therapy. The body mass index (BMI) and glycosylated hemoglobin (HbA(1c)) were recorded to assess any potential improvement in blood glucose control. The relationship between BGL and measured energy level was also investigated. Overall, there was a significant reduction of HbA(1c) from 7.48 +/- 1.21% to 6.98 +/- 1.44% (P < 0.05). There was no significant change in BMI. It was also found that higher energy levels resulted in much lower fluctuations in BGL change between meals compared to low energy levels. Moreover, the weekly mean activity score showed an increase in activity levels from the second week to the final week. This pilot study demonstrated that the Energy Monitor could improve the management of diabetes by allowing people with diabetes to view and manage daily physical activity in addition to their usual diabetes therapy.

Evaluating the accuracy, reliability, and clinical applicability of continuous glucose monitoring (CGM): Is CGM ready for real time?

PubMed

Mazze, Roger S; Strock, Ellie; Borgman, Sarah; Wesley, David; Stout, Philip; Racchini, Joel

2009-01-01

This study was designed to assess the accuracy, reliability, and contribution to clinical decision-making of two commercially available continuous glucose monitoring (CGM) devices using a novel analytical approach. Eleven individuals with type 1 diabetes and five with type 2 diabetes wore a Guardian RT (GRT) (Medtronic Minimed, Northridge, CA) or DexCom STS Continuous Monitoring System (DEX) (San Diego, CA) device for 200 h followed by an 8-h laboratory study. A subset of these subjects wore both devices simultaneously. Subjects produced 1,902 +/- 269 readings during the ambulatory phase. During the laboratory study we found: lag time of 21 +/- 5 min for GRT and 7 +/- 7 min for DEX (P < 0.005); mean absolute relative difference of 19.9% and 16.7%, respectively, for GRT and DEX; and glucose exposure (the ratio of study device/laboratory reference device [YSI Instruments, Inc., Yellow Springs, OH] area under the curve) of 95 +/- 6% for GRT and 101 +/- 13% for DEX. Reliability measured during laboratory study showed 82% for DEX and 99% for GRT. Clarke Error Grid analysis (YSI reference) showed for GRT 59% of values in zone A, 34% in zone B, and 7% in zone D and for DEX 70% in zone A, 28% in zone B, 1% in zone C, and 1% in zone D. Bland-Altman plots (YSI standard) yielded for DEX 3 mg/dL (95% confidence interval, -78 to 84 mg/dL) and for GRT -21 mg/dL (95% confidence interval, -124 to 82 mg/dL). Six of eight subjects completed both home and laboratory simultaneous use of DEX and GRT. Lag times were inconsistent between devices, ranging from 0 to 32 min; area under the curve revealed a tendency for DEX to report higher total glucose exposure than GRT for the same patient. CGM detects abnormalities in glycemic control in a manner heretofore impossible to obtain. However, our studies revealed sufficient incongruence between simultaneous laboratory blood glucose levels and interstitial fluid glucose (after calibrations) to question the fundamental assumption that interstitial fluid glucose and blood glucose could be made identical by resorting to algorithms based on concurrent blood glucose levels alone.

Real-Time Continuous Glucose Monitoring Reduces the Duration of Hypoglycemia Episodes: A Randomized Trial in Very Low Birth Weight Neonates

PubMed Central

Uettwiller, Florence; Chemin, Aude; Bonnemaison, Elisabeth; Favrais, Géraldine; Saliba, Elie; Labarthe, François

2015-01-01

Objectives Hypoglycemia is frequent in very low birth weight (VLBW) neonates and compromises their neurological outcome. The aim of this study was to compare real-time continuous glucose monitoring system (RT-CGMS) to standard methods by intermittent capillary blood glucose testing in detecting and managing hypoglycemia. Study design Forty-eight VLBW neonates were enrolled in this prospective study. During their 3 first days of life, their glucose level was monitored either by RT-CGMS (CGM-group), or by intermittent capillary glucose testing (IGM-group) associated with a blind-CGMS to detect retrospectively missed hypoglycemia. Outcomes were the number and duration of hypoglycemic (≤50mg/dl) episodes per patient detected by CGMS. Results Forty-three monitorings were analyzed (IGM n = 21, CGM n = 22), with a median recording time of 72 hours. In the IGM group, blind-CGMS revealed a significantly higher number of hypoglycemia episodes than capillary blood glucose testing (1.2±0.4 vs 0.4±0.2 episode/patient, p<0.01). In the CGM-group, the use of RT-CGMS made it possible (i) to detect the same number of hypoglycemia episodes as blind-CGMS (1.2±0.4 episode/patient), (ii) to adapt the glucose supply in neonates with hypoglycemia (increased supply during days 1 and 2), and (iii) to significantly reduce the duration of hypoglycemia episodes per patient (CGM 44[10–140] min versus IGM 95[15–520] min, p<0.05). Furthermore, it reduced the number of blood samples (CGM 16.9±1.0 vs IGM 21.9±1.0 blood sample/patient, p<0.001). Conclusion RT-CGMS played a beneficial role in managing hypoglycemia in VLBW neonates by adjusting the carbohydrate supply to the individual needs and by reducing the duration of hypoglycemia episodes. The clinical significance of the biological differences observed in our study need to be explored. PMID:25590334

Analyte Flux at a Biomaterial–Tissue Interface over Time: Implications for Sensors for Type 1 and 2 Diabetes Mellitus

PubMed Central

Ekberg, Neda Rajamand; Brismar, Kerstin; Malmstedt, Jonas; Hedblad, Mari-Anne; Adamson, Ulf; Ungerstedt, Urban; Wisniewski, Natalie

2010-01-01

Objective The very presence of an implanted sensor (a foreign body) causes changes in the adjacent tissue that may alter the analytes being sensed. The objective of this study was to investigate changes in glucose availability and local tissue metabolism at the sensor–tissue interface in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Method Microdialysis was used to model implanted sensors. Capillary glucose and subcutaneous (sc) microdialysate analytes were monitored in five T1DM and five T2DM patients. Analytes included glucose, glycolysis metabolites (lactate, pyruvate), a lipolysis metabolite (glycerol), and a protein degradation byproduct (urea). On eight consecutive days, four measurements were taken during a period of steady state blood glucose. Results Microdialysate glucose and microdialysate-to-blood-glucose ratio increased over the first several days in all patients. Although glucose recovery eventually stabilized, the lactate levels continued to rise. These trends were explained by local inflammatory and microvascular changes observed in histological analysis of biopsy samples. Urea concentrations mirrored glucose trends. Urea is neither produced nor consumed in sc tissue, and so the initially increasing urea trend is explained by increased local capillary presence during the inflammatory process. Pyruvate in T2DM microdialysate was significantly higher than in T1DM, an observation that is possibly explained by mitochondrial dysfunction in T2DM. Glycerol in T2DM microdialysate (but not in T1DM) was higher than in healthy volunteers, which is likely explained by sc insulin resistance (insulin is a potent antilipolytic hormone). Urea was also higher in microdialysate of patients with diabetes mellitus compared to healthy volunteers. Urea is a byproduct of protein degradation, which is known to be inhibited by insulin. Therefore, insulin deficiency or resistance may explain the higher urea levels. To our knowledge, this is the first histological evaluation of a human tissue biopsy containing an implanted glucose monitoring device. Conclusions Monitoring metabolic changes at a material–tissue interface combined with biopsy histology helped to formulate an understanding of physiological changes adjacent to implanted glucose sensors. Microdialysate glucose trends were similar over 1-week in T1DM and T2DM; however, differences in other analytes indicated wound healing and metabolic activities in the two patient groups differ. We propose explanations for the specific observed differences based on differential insulin insufficiency/resistance and mitochondrial dysfunction in T1DM versus T2DM. PMID:20920426

Analyte flux at a biomaterial-tissue interface over time: implications for sensors for type 1 and 2 diabetes mellitus.

PubMed

Ekberg, Neda Rajamand; Brismar, Kerstin; Malmstedt, Jonas; Hedblad, Mari-Anne; Adamson, Ulf; Ungerstedt, Urban; Wisniewski, Natalie

2010-09-01

The very presence of an implanted sensor (a foreign body) causes changes in the adjacent tissue that may alter the analytes being sensed. The objective of this study was to investigate changes in glucose availability and local tissue metabolism at the sensor-tissue interface in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Microdialysis was used to model implanted sensors. Capillary glucose and subcutaneous (sc) microdialysate analytes were monitored in five T1DM and five T2DM patients. Analytes included glucose, glycolysis metabolites (lactate, pyruvate), a lipolysis metabolite (glycerol), and a protein degradation byproduct (urea). On eight consecutive days, four measurements were taken during a period of steady state blood glucose. Microdialysate glucose and microdialysate-to-blood-glucose ratio increased over the first several days in all patients. Although glucose recovery eventually stabilized, the lactate levels continued to rise. These trends were explained by local inflammatory and microvascular changes observed in histological analysis of biopsy samples. Urea concentrations mirrored glucose trends. Urea is neither produced nor consumed in sc tissue, and so the initially increasing urea trend is explained by increased local capillary presence during the inflammatory process. Pyruvate in T2DM microdialysate was significantly higher than in T1DM, an observation that is possibly explained by mitochondrial dysfunction in T2DM. Glycerol in T2DM microdialysate (but not in T1DM) was higher than in healthy volunteers, which is likely explained by sc insulin resistance (insulin is a potent antilipolytic hormone). Urea was also higher in microdialysate of patients with diabetes mellitus compared to healthy volunteers. Urea is a byproduct of protein degradation, which is known to be inhibited by insulin. Therefore, insulin deficiency or resistance may explain the higher urea levels. To our knowledge, this is the first histological evaluation of a human tissue biopsy containing an implanted glucose monitoring device. Monitoring metabolic changes at a material-tissue interface combined with biopsy histology helped to formulate an understanding of physiological changes adjacent to implanted glucose sensors. Microdialysate glucose trends were similar over 1-week in T1DM and T2DM; however, differences in other analytes indicated wound healing and metabolic activities in the two patient groups differ. We propose explanations for the specific observed differences based on differential insulin insufficiency/resistance and mitochondrial dysfunction in T1DM versus T2DM. © 2010 Diabetes Technology Society.

Comparison of 5 reflectance meters for capillary blood glucose determination.

PubMed

Kolopp, M; Louis, J; Pointel, J P; Kohler, F; Drouin, P; Debry, G

1983-03-01

Manufacturing quality, accuracy and users opinion (i.e. medical and nurses staff and patients) were compared among five Destrostix reading reflectance-meters for home-blood-glucose-monitoring. Two machines (dextrometer and glucometer) equipped with microprocessors, integrated circuits and good quality wiring are best made. Reflectance-meter capillary blood glucose measurements were found to be accurate enough for home-blood-glucose-monitoring, compared to a reference method. However, two machines from the same brand were different in blood glucose accuracy. Glucocheck had poorest results. Users prefer small sized, battery powered machines. Glucometer appears to be best suited to home-blood-glucose-monitoring.

Monitoring of tissue optical properties using OCT: application for blood glucose analysis

NASA Astrophysics Data System (ADS)

Larin, Kirill V.; Eledrisi, Mohsen S.; Ashitkov, Taras V.; Motamedi, Massoud; Esenaliev, Rinat O.

2002-07-01

Noninvasive monitoring of tissue optical properties in real time could significantly improve diagnostics and management of various diseases. Recently we proposed to use high- resolution Optical Coherence Tomography (OCT) technique for measurement of tissue scattering coefficient at the depth of up to 1mm. Our pilot studies performed in vitro and in vivo demonstrated that measurement of tissue scattering with this technique can potentially be applied for noninvasive monitoring of blood glucose concentration. High resolution and coherent photon detection of the OCT technique allowed detection of glucose-induced changes in the scattering coefficient. In this paper we report results of in vivo studies performed in dog, New Zealand rabbits, and first human subjects. OCT system with the wavelength of 1300 nm was used in our experiments. OCT signal slope was measured and compared with actual blood glucose concentration. Bolus glucose injections and glucose clamping administrations were used in animal studies. OCT signals were recorded form human subjects during oral glucose tolerance test. Results obtained form both animal and human studies show good correlation between slope of the OCT signals and actual blood glucose concentration measured using standard glucometesr. Sensitivity and accuracy of blood glucose concentrations monitoring with the OCT is discussed. Obtained result suggest that OCT is a promising technique for noninvasive monitoring of tissue analytes including glucose.

Mouthguard biosensor with telemetry system for monitoring of saliva glucose: A novel cavitas sensor.

PubMed

Arakawa, Takahiro; Kuroki, Yusuke; Nitta, Hiroki; Chouhan, Prem; Toma, Koji; Sawada, Shin-Ichi; Takeuchi, Shuhei; Sekita, Toshiaki; Akiyoshi, Kazunari; Minakuchi, Shunsuke; Mitsubayashi, Kohji

2016-10-15

We develop detachable "Cavitas sensors" to apply to the human oral cavity for non-invasive monitoring of saliva glucose. A salivary biosensor incorporating Pt and Ag/AgCl electrodes on a mouthguard support with an enzyme membrane is developed and tested. Electrodes are formed on the polyethylene terephthalate glycol (PETG) surface of the mouthguard. The Pt working electrode is coated with a glucose oxidase (GOD) membrane. The biosensor seamlessly is integrated with a glucose sensor and a wireless measurement system. When investigating in-vitro performance, the biosensor exhibits a robust relationship between output current and glucose concentration. In artificial saliva composed of salts and proteins, the glucose sensor is capable of highly sensitive detection over a range of 5-1000µmol/L of glucose, which encompasses the range of glucose concentrations found in human saliva. We demonstrate the ability of the sensor and wireless communication module to monitor saliva glucose in a phantom jaw imitating the structure of the human oral cavity. Stable and long-term real-time monitoring (exceeding 5h) with the telemetry system is achieved. The mouthguard biosensor will be useful as a novel method for real-time non-invasive saliva glucose monitoring for better management of dental patients. Copyright © 2015 Elsevier B.V. All rights reserved.

A diabetes-specific enteral formula improves glycemic variability in patients with type 2 diabetes.

PubMed

Alish, Carolyn J; Garvey, W Timothy; Maki, Kevin C; Sacks, Gordon S; Hustead, Deborah S; Hegazi, Refaat A; Mustad, Vikkie A

2010-06-01

Well-controlled studies have demonstrated that inpatient hyperglycemia is an indicator of poor clinical outcomes, but the use of diabetes-specific enteral formulas in hospitalized patients remains a topic of great debate. In two different protocols, postprandial glycemia and insulinemia were measured in 22 subjects with diabetes fed a diabetes-specific or standard formula (protocol 1). Continuous glucose monitoring was used to assess glucose levels in 12 enterally fed patients with diabetes receiving the standard formula followed by the diabetes-specific formula continuously for 5 days each (protocol 2). End points included postprandial glycemia and insulinemia, glycemic variability (mean amplitude of glycemic excursions [MAGE]), mean glucose, and insulin use. In the postprandial response protocol, the diabetes-specific formula resulted in lower positive areas under the postprandial curve (P < 0.001) and peak glucose (P < 0.001) and insulin (P = 0.017) levels. In the protocol using continuous glucose monitoring, glycemic variability (as measured by MAGE) was lower with continuous administration of the diabetes-specific than the standard formula (64.6 +/- 6.8 mg/dL vs. 110.6 +/-15.3 mg/dL, P = 0.003). Also, administration of the diabetes-specific formula resulted in lower mean glucose concentrations during feeding (171.1 +/- 16.1 vs. 202.1 +/- 17.4 mg/dL, P = 0.024) and insulin requirements (7.8 +/- 2.3 vs. 10.9 +/- 3.3 units/day, P = 0.039) than the standard formula. Relative to the standard formula, the diabetes-specific formula reduced postprandial glycemia, mean glucose, glycemic variability, and short-acting insulin requirements. These results suggest potential clinical usefulness of a diabetes-specific enteral formula for minimizing glycemic excursions in hospitalized patients.

Non-invasive glucose monitor

NASA Technical Reports Server (NTRS)

Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

2001-01-01

A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

Cutaneous approach towards clinical and pathophysiological aspects of hyperglycemia by ATR FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Eikje, Natalja Skrebova; Sota, Takayuki; Aizawa, Katsuo

2007-07-01

Attempts were made to non-invasively detect glucose-specific spectral signals in the skin by ATR-FTIR spectroscopy. In vivo spectra were collected from the inner wrists of healthy, prediabetes and diabetes subjects in the 750-4000 cm -1 region, with a closer assessment of the glucose-related region between 1000 and 1180 cm -1. Spectra in vivo showed glucose-specific peaks at 1030, 1080, 1118 and 1151 cm -1, as a variety of glucose solutions are found in vitro. Based on the differences of intensities at 1030 and 1118 cm -1 two spectral patterns were seen: I 1118 > I 1030 for a diabetes and I 1030> I 1118 for non-diabetes subjects. The peak at 1030 cm -1 was used to assess glucose concentrations in the skin due to its good correlation with glucose concentrations in vitro. Calculated mean values of the peak at 1030 cm -1 showed evidence of correlation with blood glucose levels when grouped as <= 140, 140-200 and >= 200 mg/dL, though there was no constant correlation between them when compared before/after OGTT or at the fasting/postprandial states. Absorbances at 1030 cm -1 were not only increased in a dose-dependent manner in a diabetes patient, but were also generally higher than in non-diabetes subjects at 30 min OGTT assessment. Also we could monitor absorbances at 1030 cm -1 and determine their changes in the skin tissue at different times of OGTT. We assume that our approach to in vivo measurement and monitoring of glucose concentrations at 1030 cm -1 may be one of the indicators to assess glucose activity level and its changes in the skin tissue, and has further implications in the study of clinical and pathophysiological aspects of hyperglycemia in diabetes and non-diabetes subjects by ATR-FTIR spectroscopy.

Change of Oral to Topical Corticosteroid Therapy Exacerbated Glucose Tolerance in a Patient with Plaque Psoriasis.

PubMed

Hongo, Yui; Ashida, Kenji; Ohe, Kenji; Enjoji, Munechika; Yamaguchi, Miyuki; Kurata, Tsuyoshi; Emoto, Akiko; Yamanouchi, Hiroko; Takagi, Satoko; Mori, Hitoe; Kawata, Nozomi; Hisata, Yoshio; Sakanishi, Yuta; Izumi, Kenichi; Sugioka, Takashi; Anzai, Keizo

2017-11-13

BACKGROUND Psoriasis is known as the most frequent disease treated by long-term topical steroids. It is also known that patients with thick, chronic plaques require the highest potency topical steroids. However, the treatment is limited to up to four weeks due to risk of systemic absorption. CASE REPORT An 80-year-old man was diagnosed with type 2 diabetes 16 years before, and was being administered insulin combined with alpha glucosidase inhibitor. He was diagnosed with plaque psoriasis and his oral steroid treatment was switched to topical steroid treatment due to lack of improvement and poorly controlled blood glucose level. The hypoglycemic events improved after the psoriatic lesions improved. CONCLUSIONS Control of blood glucose level is difficult at the very beginning of topical steroid treatment for psoriasis especially if a patient is receiving insulin treatment. Intense monitoring of blood glucose level during initiation of topical steroid treatment is necessary to prevent unfavorable complications.

Quantitative detection of glucose level based on radiofrequency patch biosensor combined with volume-fixed structures.

PubMed

Qiang, Tian; Wang, Cong; Kim, Nam-Young

2017-12-15

A concept for characterizing a radiofrequency (RF) patch biosensor combined with volume-fixed structures is presented for timely monitoring of an individual's glucose levels based on frequency variation. Two types of patch biosensors-separately integrated with a backside slot (0.53μL) and a front-side tank (0.70μL) structure-were developed to achieve precise and efficient detection while excluding the effects of interference due to the liquidity, shape, and thickness of the tested glucose sample. A glucose test analyte at different concentrations (50-600mg/dL) was dropped into the volume-fixed structures. It fully interacted with the RF patch electromagnetic field, effectively and sensitively changing the resonance frequency and magnitude of the reflection coefficient. Measurement results based on the resonance frequency showed high sensitivity up to 1.13MHz and 1.97MHz per mg/dL, and low detection limits of 26.54mg/dL and 15.22mg/dL, for the two types of patch biosensors, respectively, as well as a short response time of less than 1s. Excellent reusability of the proposed biosensors was verified through three sets of measurements for each individual glucose sample. Regression analysis revealed a good linear correlation between glucose concentrations and the resonance frequency shift. Moreover, to facilitate a multi-parameter-sensitive detection of glucose, the magnitude of the reflection coefficient was also tested, and it showed a good linear correlation with the glucose concentration. Thus, the proposed approach can be adopted for distinguishing glucose solution levels, and it is a potential candidate for early-stage detection of glucose levels in diabetes patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Efficacy of Additional Canagliflozin Administration to Type 2 Diabetes Patients Receiving Insulin Therapy: Examination of Diurnal Glycemic Patterns Using Continuous Glucose Monitoring (CGM).

PubMed

Matsumura, Mihoko; Nakatani, Yuki; Tanka, Seiichi; Aoki, Chie; Sagara, Masaaki; Yanagi, Kazunori; Suzuki, Kunihiro; Aso, Yoshimasa

2017-08-01

The efficacy of administering a sodium-glucose cotransporter 2 inhibitor during insulin therapy has not been established. In this study, we examined its effects based on diurnal glycemic patterns using continuous glucose monitoring (CGM). The subjects were 15 patients who had received insulin therapy for 1 year or more. A CGM device was attached to all subjects for 1 week. The administration of canagliflozin at 100 mg was started 4 days after attachment. The mean glucose concentrations, standard deviation (SD), mean amplitude of glycemic excursions (MAGE), mean of daily difference of blood glucose (MODD), and area under the curve (AUC) (≥180, <70 mg h/dL) after the start of administration were compared with the pretreatment values. In addition, we compared changes in the number of insulin units between basal and bolus insulin. Furthermore, we investigated the influence of canagliflozin on oxidative stress markers and cytokines using 8-hydroxy-2'-deoxyguanosine (8-OHdG), tumor necrosis factor-α (TNF-α), and adiponectin as parameters. The mean glucose concentrations decreased from 161.1 to 139.1 mg/dL (P < 0.01). The SD decreased from 36.5 to 29.6 mg/dL (P = 0.05). The MAGE decreased from 89.2 to 77.4 mg/dL (P < 0.01), and the MODD decreased from 34.3 to 25.5 mg/dL (P < 0.05). All parameters showed significant improvements in diurnal changes. AUC of ≥180, i.e., the total area of blood glucose levels at or above 180 on the blood glucose curve of CGM, decreased from 339.1 to 113.6 mg/dL (P < 0.05). AUC of <70, i.e., the total area of blood glucose levels below 70 on the blood glucose curve of CGM, slightly decreased from 1.6 to 0.3 mg/dL (P = 0.08). The total number of basal insulin units decreased from 128 to 76, and that of bolus insulin decreased from 266 to 154; the dose of insulin could be markedly decreased. In addition, the mean 8-OHdG level decreased from 11.4 to 10.8 ng/mg Cre (P < 0.05), and the mean TNF-α level decreased from 2.31 to 1.79 pg/mL (P = 0.10). The mean adiponectin level increased from 5.01 to 5.53 μg/mL (P < 0.05). Canagliflozin improved blood glucose changes in type 2 diabetes using insulin. In addition, the results suggest its antioxidant actions. University Hospital Medical Information Network (UMIN no. 000019429).

Capacitive Sensing of Glucose in Electrolytes Using Graphene Quantum Capacitance Varactors.

PubMed

Zhang, Yao; Ma, Rui; Zhen, Xue V; Kudva, Yogish C; Bühlmann, Philippe; Koester, Steven J

2017-11-08

A novel graphene-based variable capacitor (varactor) that senses glucose based on the quantum capacitance effect was successfully developed. The sensor utilizes a metal-oxide-graphene varactor device structure that is inherently compatible with passive wireless sensing, a key advantage for in vivo glucose sensing. The graphene varactors were functionalized with pyrene-1-boronic acid (PBA) by self-assembly driven by π-π interactions. Successful surface functionalization was confirmed by both Raman spectroscopy and capacitance-voltage characterization of the devices. Through glucose binding to the PBA, the glucose concentration in the buffer solutions modulates the level of electrostatic doping of the graphene surface to different degrees, which leads to capacitance changes and Dirac voltage shifts. These responses to the glucose concentration were shown to be reproducible and reversible over multiple measurement cycles, suggesting promise for eventual use in wireless glucose monitoring.

[Clinical use of continuous glucose monitoring system in gestational diabetes mellitus and type 2 diabetes complicated with pregnancy].

PubMed

Song, Yilin; Yang, Huixia

2014-08-01

To compare the clinical use of continuous glucose monitoring system (CGMS) and self-monitoring blood glucose (SMBG) when monitoring blood glucose level of patients with gestational diabetes mellitus (GDM) or type 2 diabetes mellitus (DM) complicated with pregnancy. A total of 99 patients with GDM (n = 70) and type 2 DM complicated with pregnancy (n = 29) that whether hospitalized or in clinical of Peking University First Hospital were recruited from Aug 2012 to Apr 2013. The CGMS was used to monitor their blood glucose level during the 72-hour time period, while the SMBG was also taken seven times daily. The correlation between these blood glucose levels and their glycosylated hemoglobin (HbA1c) levels were analyzed by comparing the average value, the maximum and the minimum value of blood glucose, and the appeared time of these extremum values in these two monitoring methods, and the amount of insulin usage was recorded as well. (1) The maximum, minimum and the average blood glucose value in the GDM group were (8.7 ± 1.2), (4.5 ± 0.6)and (6.3 ± 0.6)mmol/L of SMBG vs. (10.1 ± 1.7), (3.1 ± 0.7), (6.0 ± 0.6) mmol/L of CGMS. These values in DM group were(10.1 ± 2.2), (4.5 ± 1.0), (6.9 ± 1.1)mmol/L of SMBG vs.(12.2 ± 2.6), (2.8 ± 0.8), (6.6 ± 1.1) mmol/L of CGMS. By using the two methods, the maximum and the average value of the two groups showed significant differences (P < 0.01) while the minimum value showed no significant differences (P > 0.05). (2) In the GDM group, the average blood glucose values of CGMS and SMBG were significantly correlated (r = 0.864, P < 0.01). The maximum values presented the same result (r = 0.734, P < 0.01). Correlation was not found in the minimum values of CGMS and SMBG (r = 0.138, P > 0.05). In the DM group, the average valves of two methods were significantly correlated (r = 0.962, P < 0.01), the maximum values showed the same result (r = 0.831, P < 0.01).It can also be observed in the minimum values (r = 0.460, P < 0.05). (3) There was significant correlation between the average value of CGMS and HbA1c level (r = 0.400, P < 0.01), and the average value of SMBG and HbA1c level were correlated (r = 0.031, P < 0.05) in the GDM group; the average values of CGMS (r = 0.695, P < 0.01) and SMBG (r = 0.673, P < 0.01) were both significantly correlated with the HbA1c level in the DM group. (4) In the GDM group, 37% (26/70) of the minimum values of SMBG appeared 30 minutes before breakfast, while 34% (24/70) of them appeared 30 minutes before lunch; 86% (60/70) of the maximum values of SMBG were evenly distributed 2 hours after each of the three meals. In the DM group, 41% (12/29) of the minimum values of SMBG presented 30 minutes before lunch, while 21% (6/29) and 14% (4/29) of them were showed 30 minutes before breakfast and dinner respectively; about 30% of the maximum values of SMBG appeared 2 hours after each of the three meals. (5) In the GDM group, 23% (16/70) of the minimum values of CGMS occurred between 0:00-2:59 am., and most of the other minimum values of CGMS were evenly distributed in the rest of the day, except for 3% (2/70) of them were found during 18:00- 20:59 pm. 43% (30/70) of the maximum values of CGMS appeared during 6:00-8:59 am., only 1% (1/70) and 3% (2/70) of them presented during 0:00-2:59 am. and 21:00-23:59 pm., and the rest were evenly distributed for the other times of the day. In the DM group, 34% (10/29) of the minimum values of CGMS were found during 0:00-2:59 am., 14% (4/29) of them appeared during 9:00-11:59 am. and 15:00-17:59 pm., 45% (13/29) of the maximum values of the CGMS presented during 6:00-8:59 am., none was found during 21:00-23:59 pm.,0:00-2:59 am. and 3:00-5:59 am., and the rest were evenly distributed for the other times of the day. (6) 64% (45/70) of the patients in the GDM group did not require for insulin treatment, while 36% (25/70) of them did. For those patients who received insulin treatment, after CGMS, 64% (16/25) of them adjusted the insulin dosage according to their blood glucose levels. In the DM group, 14% (4/29) of them did not receive insulin treatment, while for the others who did (86%, 25/29); 60% (15/25) of them adjusted the insulin dosage according to their blood glucose levels after CGMS. Both CGMS and SMBG could correctly reflect patients' blood glucose levels. It was more difficult to control the blood glucose levels in patients with type 2 DM complicated with pregnancy than the GDM patients. Compared with SMBG, CGMS could detect postprandial hyperglycemia and nocturnal hypoglycemia more effectively.

Human salivary glucose analysis by high-performance ion-exchange chromatography and pulsed amperometric detection.

PubMed

Gough, H; Luke, G A; Beeley, J A; Geddes, D A

1996-02-01

The aim of this project was to develop an analytical procedure with the required level of sensitivity for the determination of glucose concentrations in small volumes of unstimulated fasting whole saliva. The technique involves high-performance ion-exchange chromatography at high pH and pulsed amperometric detection. It has a high level of reproducibility, a sensitivity as low as 0.1 mumol/l and requires only 50 microliters samples (sensitivity = 0.002 pmol). Inhibition of glucose metabolism, by procedures such as collection into 0.1% (w/v) sodium fluoride, was shown to be essential if accurate results are to be obtained. Collection on to ice followed by storage at -20 degrees C was shown to be unsuitable and resulted in glucose loss by degradation. There were inter- and intraindividual variations in the glucose concentration in unstimulated mixed saliva (range; 0.02-0.4 mmol/l). The procedure can be used for the analysis of other salivary carbohydrates and for monitoring the clearance of dietary carbohydrates from the mouth.

Second Annual Clinical Diabetes Technology Meeting

DTIC Science & Technology

2006-05-01

glucose levels in Type 2 diabetes. He emphasized the excellent safety profile of this drug and its potential to promote weight loss in obese patients...monitoring of blood glucose (SMBG) is intended to: 1) educate patients about diet and exercise effects on glycemia; 2) protect patients by allowing...glucocentric. To reduce the risk of cardiovascular disease the comorbid risk factors, obesity , hypertension, dyslipidemia and the prothrombotic state need to be

Impaired brain energy gain upon a glucose load in obesity.

PubMed

Wardzinski, Ewelina K; Kistenmacher, Alina; Melchert, Uwe H; Jauch-Chara, Kamila; Oltmanns, Kerstin M

2018-03-06

There is evidence that the brain's energy status is lowered in obesity despite of chronic hypercaloric nutrition. The underlying mechanisms are unknown. We hypothesized that the brain of obese people does not appropriately generate energy in response to a hypercaloric supply. Glucose was intravenously infused in 17 normal weights and 13 obese participants until blood glucose concentrations reached the postprandial levels of 7 mmol/L and 10 mmol/L. Changes in cerebral adenosine triphosphate (ATP) and phosphocreatine (PCr) content were measured by 31 phosphorus magnetic resonance spectroscopy and stress hormonal measures regulating glucose homeostasis were monitored. Because vitamin C is crucial for a proper neuronal energy synthesis we determined circulating concentrations during the experimental testing. Cerebral high-energy phosphates were increased at blood glucose levels of 7 mmol/L in normal weights, which was completely missing in the obese. Brain energy content moderately raised only at blood glucose levels of 10 mmol/L in obese participants. Vitamin C concentrations generally correlated with the brain energy content at blood glucose concentrations of 7 mmol/L. Our data demonstrate an inefficient cerebral energy gain upon a glucose load in obese men, which may result from a dysfunctional glucose transport across the blood-brain barrier or a downregulated energy synthesis in mitochondrial oxidation processes. Our finding offers an explanation for the chronic neuroenergetic deficiency and respectively missing satiety perception in obesity. Copyright © 2018. Published by Elsevier Inc.

A review of implantable biosensors for closed-loop glucose control and other drug delivery applications.

PubMed

Scholten, Kee; Meng, Ellis

2018-06-15

Closed-loop drug delivery promises autonomous control of pharmacotherapy through the continuous monitoring of biomarker levels. For decades, researchers have strived for portable closed-loop systems capable of treating ambulatory patients with chronic conditions such as diabetes mellitus. After years of development, the first of these systems have left the laboratory and entered commercial use. This long-awaited advance reflects recent development of chronically stable implantable biosensors able to accurately measure biomarker levels in vivo. This review discusses the role of implantable biosensors in closed-loop drug delivery applications, with the intent to provide a resource for engineers and researchers studying such systems. We provide an overview of common biosensor designs and review the principle challenges in implementing long indwelling sensors: namely device sensitivity, selectivity, and lifetime. This review examines novel advances in transducer design, biological interface, and material biocompatibility, with a focus on recent academic and commercial work which provide successful strategies to overcome perennial challenges. This review focuses primarily on the topics of closed-loop glucose control and continuous glucose monitoring biosensors, which make up the overwhelming majority of published research in this area. We conclude with an overview of recent advances in closed-loop systems targeting applications outside blood glucose management. Copyright © 2018 Elsevier B.V. All rights reserved.

Optical coherence tomography for blood glucose monitoring through signal attenuation

NASA Astrophysics Data System (ADS)

De Pretto, Lucas R.; Yoshimura, Tania M.; Ribeiro, Martha S.; de Freitas, Anderson Z.

2016-03-01

Development of non-invasive techniques for glucose monitoring is crucial to improve glucose control and treatment adherence in patients with diabetes. Hereafter, Optical Coherence Tomography (OCT) may offer a good alternative for portable glucometers, since it uses light to probe samples. Changes in the object of interest can alter the intensity of light returning from the sample and, through it, one can estimate the sample's attenuation coefficient (μt) of light. In this work, we aimed to explore the behavior of μt of mouse's blood under increasing glucose concentrations. Different samples were prepared in four glucose concentrations using a mixture of heparinized blood, phosphate buffer saline and glucose. Blood glucose concentrations were measured with a blood glucometer, for reference. We have also prepared other samples diluting the blood in isotonic saline solution to check the effect of a higher multiple-scattering component on the ability of the technique to differentiate glucose levels based on μt. The OCT system used was a commercial Spectral Radar OCT with 930 nm central wavelength and spectral bandwidth (FWHM) of 100 nm. The system proved to be sensitive for all blood glucose concentrations tested, with good correlations with the obtained attenuation coefficients. A linear tendency was observed, with an increase in attenuation with higher values of glucose. Statistical difference was observed between all groups (p<0.001). This work opens the possibility towards a non-invasive diagnostic modality using OCT for glycemic control, which eliminates the use of analytes and/or test strips, as in the case with commercially available glucometers.

Usefulness of continuous glucose monitoring for the diagnosis of hypoglycemia after a gastric bypass in a patient previously treated for type 2 diabetes.

PubMed

Hanaire, Hélène; Dubet, Audrey; Chauveau, Marie-Emilie; Anduze, Yves; Fernandes, Martine; Melki, Vincent; Ritz, Patrick

2010-01-01

Hypoglycemia is rare after a gastric bypass and can be taken for a dumping syndrome. There is no report in the literature of the contribution of continuous glucose monitoring to the diagnosis of hypoglycemia in these circumstances. The present case report shows that continuous glucose monitoring can be a useful tool for the diagnosis and the management of such episodes. Continuous glucose monitoring revealed hypoglycemic episodes in free living circumstances that were not present during 72-h fasting. These episodes followed wide hyperglycemic swings. No such episode resumed over 8 months after specific dietary advices and treatment by 50 mg TID of acarbose. Because hypoglycemia can be difficult to diagnose from dumping syndrome, continuous glucose monitoring is a very useful tool revealing the episodes in free living circumstances and can be used to monitor the treatment success.

Hypoglycaemia of the newborn: a review.

PubMed Central

Williams, A. F.

1997-01-01

It is almost a century since hypoglycaemia (a reduction in the glucose concentration of circulating blood) was first described in children, and over 50 years since the condition was first recognized in infants. Nevertheless, controversy still surrounds the definition, significance, and management of neonatal hypoglycaemia. Technological developments such as bedside glucose monitoring have, paradoxically, exacerbated rather than eased the situation. This article reviews the literature on hypoglycaemia of the newborn, and covers the following: historical aspects; glucose homeostasis and metabolic adaptation at birth; the effect of low blood glucose levels on the central nervous system; the definition of hypoglycaemia; screening; prevention; treatment; research needs; and concludes with recommendations for prevention and management. PMID:9277014

Is type 2 diabetes really resolved after laparoscopic sleeve gastrectomy? Glucose variability studied by continuous glucose monitoring.

PubMed

Capoccia, D; Coccia, F; Guida, A; Rizzello, M; De Angelis, F; Silecchia, G; Leonetti, F

2015-01-01

The study was carried out on type 2 diabetic obese patients who underwent laparoscopic sleeve gastrectomy (LSG). Patients underwent regular glycemic controls throughout 3 years and all patients were defined cured from diabetes according to conventional criteria defined as normalization of fasting glucose levels and glycated hemoglobin in absence of antidiabetic therapy. After 3 years of follow-up, Continuous Glucose Monitoring (CGM) was performed in each patient to better clarify the remission of diabetes. In this study, we found that the diabetes resolution after LSG occurred in 40% of patients; in the other 60%, even if they showed a normal fasting glycemia and A1c, patients spent a lot of time in hyperglycemia. During the oral glucose tolerance test (OGTT), we found that 2 h postload glucose determinations revealed overt diabetes only in a small group of patients and might be insufficient to exclude the diagnosis of diabetes in the other patients who spent a lot of time in hyperglycemia, even if they showed a normal glycemia (<140 mg/dL) at 120 minutes OGTT. These interesting data could help clinicians to better individualize patients in which diabetes is not resolved and who could need more attention in order to prevent chronic complications of diabetes.

Evaluating the accuracy and large inaccuracy of two continuous glucose monitoring systems.

PubMed

Leelarathna, Lalantha; Nodale, Marianna; Allen, Janet M; Elleri, Daniela; Kumareswaran, Kavita; Haidar, Ahmad; Caldwell, Karen; Wilinska, Malgorzata E; Acerini, Carlo L; Evans, Mark L; Murphy, Helen R; Dunger, David B; Hovorka, Roman

2013-02-01

This study evaluated the accuracy and large inaccuracy of the Freestyle Navigator (FSN) (Abbott Diabetes Care, Alameda, CA) and Dexcom SEVEN PLUS (DSP) (Dexcom, Inc., San Diego, CA) continuous glucose monitoring (CGM) systems during closed-loop studies. Paired CGM and plasma glucose values (7,182 data pairs) were collected, every 15-60 min, from 32 adults (36.2±9.3 years) and 20 adolescents (15.3±1.5 years) with type 1 diabetes who participated in closed-loop studies. Levels 1, 2, and 3 of large sensor error with increasing severity were defined according to absolute relative deviation greater than or equal to ±40%, ±50%, and ±60% at a reference glucose level of ≥6 mmol/L or absolute deviation greater than or equal to ±2.4 mmol/L,±3.0 mmol/L, and ±3.6 mmol/L at a reference glucose level of <6 mmol/L. Median absolute relative deviation was 9.9% for FSN and 12.6% for DSP. Proportions of data points in Zones A and B of Clarke error grid analysis were similar (96.4% for FSN vs. 97.8% for DSP). Large sensor over-reading, which increases risk of insulin over-delivery and hypoglycemia, occurred two- to threefold more frequently with DSP than FSN (once every 2.5, 4.6, and 10.7 days of FSN use vs. 1.2, 2.0, and 3.7 days of DSP use for Level 1-3 errors, respectively). At levels 2 and 3, large sensor errors lasting 1 h or longer were absent with FSN but persisted with DSP. FSN and DSP differ substantially in the frequency and duration of large inaccuracy despite only modest differences in conventional measures of numerical and clinical accuracy. Further evaluations are required to confirm that FSN is more suitable for integration into closed-loop delivery systems.

CdSe/ZnS Quantum Dots-Labeled Mesenchymal Stem Cells for Targeted Fluorescence Imaging of Pancreas Tissues and Therapy of Type 1 Diabetic Rats

NASA Astrophysics Data System (ADS)

Liu, Haoqi; Tang, Wei; Li, Chao; Lv, Pinlei; Wang, Zheng; Liu, Yanlei; Zhang, Cunlei; Bao, Yi; Chen, Haiyan; Meng, Xiangying; Song, Yan; Xia, Xiaoling; Pan, Fei; Cui, Daxiang; Shi, Yongquan

2015-06-01

Mesenchymal stem cells (MSCs) have been used for therapy of type 1 diabetes mellitus. However, the in vivo distribution and therapeutic effects of transplanted MSCs are not clarified well. Herein, we reported that CdSe/ZnS quantum dots-labeled MSCs were prepared for targeted fluorescence imaging and therapy of pancreas tissues in rat models with type 1 diabetes. CdSe/ZnS quantum dots were synthesized, their biocompatibility was evaluated, and then, the appropriate concentration of quantum dots was selected to label MSCs. CdSe/ZnS quantum dots-labeled MSCs were injected into mouse models with type 1 diabetes via tail vessel and then were observed by using the Bruker In-Vivo F PRO system, and the blood glucose levels were monitored for 8 weeks. Results showed that prepared CdSe/ZnS quantum dots owned good biocompatibility. Significant differences existed in distribution of quantum dots-labeled MSCs between normal control rats and diabetic rats ( p < 0.05). The ratios of the fluorescence intensity (RFI) analysis showed an accumulation rate of MSCs in the pancreas of rats in the diabetes group, and was about 32 %, while that in the normal control group rats was about 18 %. The blood glucose levels were also monitored for 8 weeks after quantum dots-labeled MSC injection. Statistical differences existed between the blood glucose levels of the diabetic rat control group and MSC-injected diabetic rat group ( p < 0.01), and the MSC-injected diabetic rat group displayed lower blood glucose levels. In conclusion, CdSe/ZnS-labeled MSCs can target in vivo pancreas tissues in diabetic rats, and significantly reduce the blood glucose levels in diabetic rats, and own potential application in therapy of diabetic patients in the near future.

CdSe/ZnS Quantum Dots-Labeled Mesenchymal Stem Cells for Targeted Fluorescence Imaging of Pancreas Tissues and Therapy of Type 1 Diabetic Rats.

PubMed

Liu, Haoqi; Tang, Wei; Li, Chao; Lv, Pinlei; Wang, Zheng; Liu, Yanlei; Zhang, Cunlei; Bao, Yi; Chen, Haiyan; Meng, Xiangying; Song, Yan; Xia, Xiaoling; Pan, Fei; Cui, Daxiang; Shi, Yongquan

2015-12-01

Mesenchymal stem cells (MSCs) have been used for therapy of type 1 diabetes mellitus. However, the in vivo distribution and therapeutic effects of transplanted MSCs are not clarified well. Herein, we reported that CdSe/ZnS quantum dots-labeled MSCs were prepared for targeted fluorescence imaging and therapy of pancreas tissues in rat models with type 1 diabetes. CdSe/ZnS quantum dots were synthesized, their biocompatibility was evaluated, and then, the appropriate concentration of quantum dots was selected to label MSCs. CdSe/ZnS quantum dots-labeled MSCs were injected into mouse models with type 1 diabetes via tail vessel and then were observed by using the Bruker In-Vivo F PRO system, and the blood glucose levels were monitored for 8 weeks. Results showed that prepared CdSe/ZnS quantum dots owned good biocompatibility. Significant differences existed in distribution of quantum dots-labeled MSCs between normal control rats and diabetic rats (p < 0.05). The ratios of the fluorescence intensity (RFI) analysis showed an accumulation rate of MSCs in the pancreas of rats in the diabetes group which was about 32 %, while that in the normal control group rats was about 18 %. The blood glucose levels were also monitored for 8 weeks after quantum dots-labeled MSC injection. Statistical differences existed between the blood glucose levels of the diabetic rat control group and MSC-injected diabetic rat group (p < 0.01), and the MSC-injected diabetic rat group displayed lower blood glucose levels. In conclusion, CdSe/ZnS-labeled MSCs can target in vivo pancreas tissues in diabetic rats, and significantly reduce the blood glucose levels in diabetic rats, and own potential application in therapy of diabetic patients in the near future.

Comparison of glucose fluctuations between day- and night-time measured using a continuous glucose monitoring system in diabetic dogs.

PubMed

Mori, Akihiro; Kurishima, Miyuki; Oda, Hitomi; Saeki, Kaori; Arai, Toshiro; Sako, Toshinori

2013-01-31

Monitoring of blood glucose concentration is important to evaluate the diabetic status of dogs. Continuous glucose monitoring systems (CGMS) have been applied in veterinary medicine for glucose monitoring in diabetic dogs. The purpose of the study was to evaluate the daily glycemic profiles obtained with CGMS and compare glucose fluctuations between day- and night-time in diabetic dogs. Five diabetic dogs were used in this study and were treated with either NPH insulin or insulin detemir. For data analyses, day-time was defined as 9:00 am-9:00 pm and night-time as 9:00 pm-9:00 am. Using glucose profiles, we determined the mean glucose concentrations (1- and 12-hr intervals), and times spent in hyperglycemia >200 mg/dl or hypoglycemia <60 mg/dl. None of the parameters differed significantly between day-time and night-time in dogs treated with NPH insulin or insulin detemir. In conclusion, this study confirmed, using CGMS, that there are no differences in glucose fluctuations between day- and night-time, in diabetic dogs on a similar feeding regimen and insulin administration.

Enhancing the accuracy of subcutaneous glucose sensors: a real-time deconvolution-based approach.

PubMed

Guerra, Stefania; Facchinetti, Andrea; Sparacino, Giovanni; Nicolao, Giuseppe De; Cobelli, Claudio

2012-06-01

Minimally invasive continuous glucose monitoring (CGM) sensors can greatly help diabetes management. Most of these sensors consist of a needle electrode, placed in the subcutaneous tissue, which measures an electrical current exploiting the glucose-oxidase principle. This current is then transformed to glucose levels after calibrating the sensor on the basis of one, or more, self-monitoring blood glucose (SMBG) samples. In this study, we design and test a real-time signal-enhancement module that, cascaded to the CGM device, improves the quality of its output by a proper postprocessing of the CGM signal. In fact, CGM sensors measure glucose in the interstitium rather than in the blood compartment. We show that this distortion can be compensated by means of a regularized deconvolution procedure relying on a linear regression model that can be updated whenever a pair of suitably sampled SMBG references is collected. Tests performed both on simulated and real data demonstrate a significant accuracy improvement of the CGM signal. Simulation studies also demonstrate the robustness of the method against departures from nominal conditions, such as temporal misplacement of the SMBG samples and uncertainty in the blood-to-interstitium glucose kinetic model. Thanks to its online capabilities, the proposed signal-enhancement algorithm can be used to improve the performance of CGM-based real-time systems such as the hypo/hyper glycemic alert generators or the artificial pancreas.

Patients' and caregivers' experiences of using continuous glucose monitoring to support diabetes self-management: qualitative study.

PubMed

Lawton, J; Blackburn, M; Allen, J; Campbell, F; Elleri, D; Leelarathna, L; Rankin, D; Tauschmann, M; Thabit, H; Hovorka, R

2018-02-20

Continuous glucose monitoring (CGM) enables users to view real-time interstitial glucose readings and provides information on the direction and rate of change of blood glucose levels. Users can also access historical data to inform treatment decisions. While the clinical and psychological benefits of CGM are well established, little is known about how individuals use CGM to inform diabetes self-management. We explored participants' experiences of using CGM in order to provide recommendations for supporting individuals to make optimal use of this technology. In-depth interviews (n = 24) with adults, adolescents and parents who had used CGM for ≥4 weeks; data were analysed thematically. Participants found CGM an empowering tool because they could access blood glucose data effortlessly, and trend arrows enabled them to see whether blood glucose was rising or dropping and at what speed. This predicative information aided short-term lifestyle planning and enabled individuals to take action to prevent hypoglycaemia and hyperglycaemia. Having easy access to blood glucose data on a continuous basis also allowed participants to develop a better understanding of how insulin, activity and food impacted on blood glucose. This understanding was described as motivating individuals to make dietary changes and break cycles of over-treating hypoglycaemia and hyperglycaemia. Participants also described how historical CGM data provided a more nuanced picture of blood glucose control than was possible with blood glucose self-monitoring and, hence, better information to inform changes to background insulin doses and mealtime ratios. However, while participants expressed confidence making immediate adjustments to insulin and lifestyle to address impending hypoglycaemia and hypoglycaemia, most described needing and expecting health professionals to interpret historical CGM data and determine changes to background insulin doses and mealtime ratios. While alarms could reinforce a sense of hypoglycaemic safety, some individuals expressed ambivalent views, especially those who perceived alarms as signalling personal failure to achieve optimal glycaemic control. CGM can be an empowering and motivational tool which enables participants to fine-tune and optimize their blood glucose control. However, individuals may benefit from psycho-social education, training and/or technological support to make optimal use of CGM data and use alarms appropriately.

Comparison of Insulin Glargine 300 Units/mL and 100 Units/mL in Adults With Type 1 Diabetes: Continuous Glucose Monitoring Profiles and Variability Using Morning or Evening Injections.

PubMed

Bergenstal, Richard M; Bailey, Timothy S; Rodbard, David; Ziemen, Monika; Guo, Hailing; Muehlen-Bartmer, Isabel; Ahmann, Andrew J

2017-04-01

The objective of this study was to compare glucose control in participants with type 1 diabetes receiving insulin glargine 300 units/mL (Gla-300) or glargine 100 units/mL (Gla-100) in the morning or evening, in combination with mealtime insulin. In this 16-week, exploratory, open-label, parallel-group, two-period crossover study (clinicaltrials.gov identifier NCT01658579), 59 adults with type 1 diabetes were randomized (1:1:1:1) to once-daily Gla-300 or Gla-100 given in the morning or evening (with crossover in the injection schedule). The primary efficacy end point was the mean percentage of time in the target glucose range (80-140 mg/dL), as measured using continuous glucose monitoring (CGM), during the last 2 weeks of each 8-week period. Additional end points included other CGM glycemic control parameters, hypoglycemia (per self-monitored plasma glucose [SMPG]), and adverse events. The percentage of time within the target glucose range was comparable between the Gla-300 and Gla-100 groups. There was significantly less increase in CGM-based glucose during the last 4 h of the 24-h injection interval for Gla-300 compared with Gla-100 (least squares mean difference -14.7 mg/dL [95% CI -26.9 to -2.5]; P = 0.0192). Mean 24-h glucose curves for the Gla-300 group were smoother (lower glycemic excursions), irrespective of morning or evening injection. Four metrics of intrasubject interstitial glucose variability showed no difference between Gla-300 and Gla-100. Nocturnal confirmed (<54 mg/dL by SMPG) or severe hypoglycemia rate was lower for Gla-300 participants than for Gla-100 participants (4.0 vs. 9.0 events per participant-year; rate ratio 0.45 [95% CI 0.24-0.82]). Less increase in CGM-based glucose levels in the last 4 h of the 24-h injection interval, smoother average 24-h glucose profiles irrespective of injection time, and reduced nocturnal hypoglycemia were observed with Gla-300 versus Gla-100. © 2017 by the American Diabetes Association.

Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform.

PubMed

Emaminejad, Sam; Gao, Wei; Wu, Eric; Davies, Zoe A; Yin Yin Nyein, Hnin; Challa, Samyuktha; Ryan, Sean P; Fahad, Hossain M; Chen, Kevin; Shahpar, Ziba; Talebi, Salmonn; Milla, Carlos; Javey, Ali; Davis, Ronald W

2017-05-02

Perspiration-based wearable biosensors facilitate continuous monitoring of individuals' health states with real-time and molecular-level insight. The inherent inaccessibility of sweat in sedentary individuals in large volume (≥10 µL) for on-demand and in situ analysis has limited our ability to capitalize on this noninvasive and rich source of information. A wearable and miniaturized iontophoresis interface is an excellent solution to overcome this barrier. The iontophoresis process involves delivery of stimulating agonists to the sweat glands with the aid of an electrical current. The challenge remains in devising an iontophoresis interface that can extract sufficient amount of sweat for robust sensing, without electrode corrosion and burning/causing discomfort in subjects. Here, we overcame this challenge through realizing an electrochemically enhanced iontophoresis interface, integrated in a wearable sweat analysis platform. This interface can be programmed to induce sweat with various secretion profiles for real-time analysis, a capability which can be exploited to advance our knowledge of the sweat gland physiology and the secretion process. To demonstrate the clinical value of our platform, human subject studies were performed in the context of the cystic fibrosis diagnosis and preliminary investigation of the blood/sweat glucose correlation. With our platform, we detected the elevated sweat electrolyte content of cystic fibrosis patients compared with that of healthy control subjects. Furthermore, our results indicate that oral glucose consumption in the fasting state is followed by increased glucose levels in both sweat and blood. Our solution opens the possibility for a broad range of noninvasive diagnostic and general population health monitoring applications.

Wearable Contact Lens Biosensors for Continuous Glucose Monitoring Using Smartphones.

PubMed

Elsherif, Mohamed; Hassan, Mohammed Umair; Yetisen, Ali K; Butt, Haider

2018-05-17

Low-cost, robust, and reusable continuous glucose monitoring systems that can provide quantitative measurements at point-of-care settings is an unmet medical need. Optical glucose sensors require complex and time-consuming fabrication processes, and their readouts are not practical for quantitative analyses. Here, a wearable contact lens optical sensor was created for the continuous quantification of glucose at physiological conditions, simplifying the fabrication process and facilitating smartphone readouts. A photonic microstructure having a periodicity of 1.6 μm was printed on a glucose-selective hydrogel film functionalized with phenylboronic acid. Upon binding with glucose, the microstructure volume swelled, which modulated the periodicity constant. The resulting change in the Bragg diffraction modulated the space between zero- and first-order spots. A correlation was established between the periodicity constant and glucose concentration within 0-50 mM. The sensitivity of the sensor was 12 nm mM -1 , and the saturation response time was less than 30 min. The sensor was integrated with commercial contact lenses and utilized for continuous glucose monitoring using smartphone camera readouts. The reflected power of the first-order diffraction was measured via a smartphone application and correlated to the glucose concentrations. A short response time of 3 s and a saturation time of 4 min was achieved in the continuous monitoring mode. Glucose-sensitive photonic microstructures may have applications in point-of-care continuous monitoring devices and diagnostics at home settings.

Effect of ezetimibe on lipid and glucose metabolism after a fat and glucose load.

PubMed

Hiramitsu, Shinya; Miyagishima, Kenji; Ishii, Junichi; Matsui, Shigeru; Naruse, Hiroyuki; Shiino, Kenji; Kitagawa, Fumihiko; Ozaki, Yukio

2012-11-01

The clinical benefit of ezetimibe, an intestinal cholesterol transporter inhibitor, for treatment of postprandial hyperlipidemia was assessed in subjects who ingested a high-fat and high-glucose test meal to mimic westernized diet. We enrolled 20 male volunteers who had at least one of the following: waist circumference ≥ 85 cm, body mass index ≥ 25 kg/m(2), or triglycerides (TG) from 150 to 400mg/dL. After 4 weeks of treatment with ezetimibe (10mg/day), the subjects ingested a high-fat and high-glucose meal. Then changes in serum lipid and glucose levels were monitored after 0, 2, 4, and 6h, and the area under the curve (AUC) was calculated for the change in each parameter. At 4 and 6h postprandially, TG levels were decreased (p<0.01) after 4 weeks of ezetimibe treatment, and the AUC for TG was also decreased (p<0.01). Apolipoprotein B48 (apo-B48) levels at 4 and 6h postprandially were significantly decreased after ezetimibe treatment (p<0.01 and p<0.001, respectively), and the AUC for apo-B48 was also significantly decreased (p<0.01). Blood glucose and insulin levels at 2h postprandially were significantly decreased by ezetimibe (p<0.05). The AUCs for blood glucose and insulin were also significantly decreased (p<0.05 and p<0.01, respectively). Since ezetimibe improved postprandial lipid and glucose metabolism, this drug is likely to be beneficial for dyslipidemia in patients with postprandial metabolic abnormalities. Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

PEGylation of Concanavalin A to decrease nonspecific interactions in a fluorescent glucose sensor

NASA Astrophysics Data System (ADS)

Abraham, Alexander A.; Cummins, Brian M.; Locke, Andrea K.; Grunlan, Melissa A.; Coté, Gerard L.

2014-02-01

The ability of people with diabetes to both monitor and regulate blood sugar levels is limited by the conventional "finger-prick" test that provides intermittent, single point measurements. Toward the development of a continuous glucose monitoring (CGM) system, the lectin, Concanavalin A (ConA), has been utilized as a component in a Förster resonance energy transfer (FRET), competitive glucose binding assay. Recently, to avoid reversibility problems associated with ConA aggregation, a suitable competing ligand labeled with 8-aminopyrene-1,3,6-trisulfonic acid trisodium salt (APTS) has been engineered. However, its ability to function as part of a glucose sensing assay is compromised due to the negative charge (at physiological pH) of native ConA that gives rise to non-specific binding with other ConA groups as well as with electrostatically charged assay-delivery carriers. To minimize these undesirable interactions, we have conjugated ConA with monomethoxy-poly(ethylene glycol) (mPEG) (i.e. "PEGylation"). In this preliminary research, fluorescently-labeled ConA was successfully PEGylated with mPEG-Nhydroxylsuccinimide( succinimidyl carbonate) (mPEG-NHS(SC)). The FRET response of APTS-labeled competing ligand (donor) conveyed an increase in the fluorescence intensity with increasing glucose concentrations.

Glucose Measurement: Time for a Gold Standard

PubMed Central

Hagvik, Joakim

2007-01-01

There is no internationally recognized reference method for the measurement of blood glucose. The Centers for Disease Control and Prevention (CDC) highlighted the need for standardization some years ago when a project was started. The project objectives were to (1) investigate whether there are significant differences in calibration levels among currently used glucose monitors for home use and (2) develop a reference method for glucose determination. A first study confirmed the assumption that currently used home-use monitors differ significantly and that standardization is necessary in order to minimize variability and to improve patient care. As a reference method, CDC recommended a method based on isotope dilution gas chromatography–mass spectrometry, an assay that has received support from clinical chemists worldwide. CDC initiated a preliminary study to establish the suitability of this method, but then the project came to a halt. It is hoped that CDC, with support from the industry, as well as academic and professional organizations such as the American Association for Clinical Chemistry and International Federation of Clinical Chemistry and Laboratory Medicine, will be able to finalize the project and develop the long-awaited and much needed “gold standard” for glucose measurement. PMID:19888402

Fabrication of flexible and disposable carbon paste-based electrodes and their electrochemical sensing

NASA Astrophysics Data System (ADS)

Aryasomayajula, Lavanya; Varadan, Vijay K.

2008-03-01

The paper describes a disposable electrochemical biosensor for glucose monitoring. The sensor is based on carbon paste immobilized with glucose oxidase and upon screen printed electrodes. The sensor has been tested effectively for the blood glucose levels corresponding to normal (70 to 99 mg/dL or 3.9 to5.5 mmol/L), pre-diabetic (100 to 125 mg/dL or 5.6 to 6.9 mmol/L) and diabetic (>126 mg/dL or 7.0 mmol/L). The calibration curve and the sensitivity of the sensor were measured.

Glucose Monitoring in Individuals With Diabetes Using a Long-Term Implanted Sensor/Telemetry System and Model.

PubMed

Lucisano, Joseph Y; Routh, Timothy L; Lin, Joe T; Gough, David A

2017-09-01

The use of a fully implanted first-generation prototype sensor/telemetry system is described for long-term monitoring of subcutaneous tissue glucose in a small cohort of people with diabetes. Sensors are based on a membrane containing immobilized glucose oxidase and catalase coupled to oxygen electrodes and a telemetry system, integrated as an implant. The devices remained implanted for up to 180 days, with signals transmitted every 2 min to external receivers. The data include signal recordings from glucose clamps and spontaneous glucose excursions, matched, respectively, to reference blood glucose and finger-stick values. The sensor signals indicate dynamic tissue glucose, for which there is no independent standard, and a model describing the relationship between blood glucose and the signal is, therefore, included. The values of all model parameters have been estimated, including the permeability of adjacent tissues to glucose, and equated to conventional mass transfer parameters. As a group, the sensor calibration varied randomly at an average rate of -2.6%/week. Statistical correlation indicated strong association between the sensor signals and reference glucose values. Continuous long-term glucose monitoring in individuals with diabetes is feasible with this system. All therapies for diabetes are based on glucose control, and therefore, require glucose monitoring. This fully implanted long-term sensor/telemetry system may facilitate a new era of management of the disease.

Glucose Monitoring in Individuals with Diabetes using a Long-Term Implanted Sensor/Telemetry System and Model

PubMed Central

Lucisano, Joseph Y.; Routh, Timothy L.; Lin, Joe T.; Gough, David A.

2017-01-01

Objective The use of a fully implanted, first-generation prototype sensor/telemetry system is described for long-term monitoring of subcutaneous tissue glucose in a small cohort of people with diabetes. Methods Sensors are based on a membrane containing immobilized glucose oxidase and catalase coupled to oxygen electrodes and a telemetry system, integrated as an implant. The devices remained implanted for up to 180 days, with signals transmitted every 2 minutes to external receivers. Results The data include signal recordings from glucose clamps and spontaneous glucose excursions, matched respectively to reference blood glucose and finger-stick values. The sensor signals indicate dynamic tissue glucose, for which there is no independent standard, and a model describing the relationship between blood glucose and the signal is therefore included. The values of all model parameters have been estimated, including the permeability of adjacent tissues to glucose, and equated to conventional mass transfer parameters. As a group, the sensor calibration varied randomly at an average rate of −2.6%/week. Statistical correlation indicated strong association between the sensor signals and reference glucose values. Conclusions Continuous, long-term glucose monitoring in individuals with diabetes is feasible with this system. Significance All therapies for diabetes are based on glucose control and therefore require glucose monitoring. This fully implanted, long-term sensor/telemetry system may facilitate a new era of management of the disease. PMID:27775510

Continuous Glucose Monitoring For Patients with Diabetes

PubMed Central

2011-01-01

Executive Summary Objective To determine the effectiveness and cost-effectiveness of continuous glucose monitoring combined with self-monitoring of blood glucose compared with self-monitoring of blood glucose alone in the management of diabetes. Clinical Need: Condition and Target Population Diabetes is a chronic metabolic disorder that interferes with the body’s ability to produce or effectively use insulin. In 2005, an estimated 816,000 Ontarians had diabetes representing 8.8% of the province’s population. Type 1 or juvenile onset diabetes is a life-long disorder that commonly manifests in children and adolescents. It represents about 10% of the total diabetes population and involves immune-mediated destruction of insulin producing cells in the pancreas. The loss of these cells necessitates insulin therapy. Type 2 or “adult-onset” diabetes represents about 90% of the total diabetes population and is marked by a resistance to insulin or insufficient insulin secretion. The risk of developing type 2 diabetes increases with age, obesity and lack of physical activity. Approximately 30% of patients with type 2 diabetes eventually require insulin therapy. Technology Continuous glucose monitors (CGM) measure glucose levels in the interstitial fluid surrounding skin cells. These measurements supplement conventional self monitoring of blood glucose (SMBG) by monitoring the glucose fluctuations continuously over a stipulated period of time, thereby identifying fluctuations that would not be identified with SMBG alone. To use a CGM, a sensor is inserted under the skin to measure glucose in the interstitial fluid. The sensor is wired to a transmitter. The device requires calibration using a capillary blood glucose measurement. Each sensor continuously measures glucose every 5-10 seconds averaging these values every 5 minutes and storing this data in the monitors memory. Depending on the device used, the algorithm in the device can measure glucose over a 3 or 6 day period using one sensor. After the 3 or 6 day period, a new sensor is required. The device is equipped with alarms which warn the patient of impending hypo-or hyperglycemia. Two types of CGM are available: Systems that is stored in a monitor and can be downloaded later. Real time systems that continuously provide the actual glucose concentration on a display. Research Questions What is the effectiveness and cost-effectiveness of CGM combined with SMBG compared with SMBG alone in the management of diabetes? Research Methods Literature Search Search Strategy A literature search was performed on September 15, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 2002 until September 15, 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology. Inclusion Criteria English language Randomized controlled trials (N>30 patients) Adults or pediatric patients with insulin dependent diabetes (type 1 or 2 or gestational) Studies comparing CGM plus SMBG versus SMBG alone Exclusion Criteria Case studies Studies that did not compare CGM plus SMBG versus SMBG alone Studies that did not report statistical analysis of outcomes or data was unextractable Outcomes of Interest Change in glycosylated hemoglobin (HbA1c) Frequency or duration of hypo-or hyperglycemic episodes or euglycemia Adverse effects Summary of Findings Moderate quality evidence that CGM + SMBG: is not more effective than self monitoring of blood glucose (SMBG) alone in the reduction of HbA1c using insulin infusion pumps for Type 1 diabetes. is not more effective than SMBG alone in the reduction of hypoglycemic or severe hypoglycemic events using insulin infusion pumps for Type 1 diabetes. PMID:23074416

The association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes.

PubMed

Sampson, L; Dasgupta, K; Ross, N A

2014-12-01

We examined the association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes in a multi-ethnic and socio-economically diverse patient group. Medical charts at a Toronto gestational diabetes clinic were reviewed for women with a recorded pregnancy between 1 March 2006 and 26 April 2011. One-hour 50-g glucose challenge test values and postal code data were abstracted. Postal codes were merged with 2006 Canadian census data to compute neighbourhood-level ethnic concentration (% recent immigrants, % visible minorities) and material deprivation (% low education, % low income, single-parent households). We compared women in the highest neighbourhood quintiles for both ethnic concentration and material deprivation with all other women to explore an association between marginalization and diagnostic glucose levels. Multivariate regression models of glucose challenge test values and insulin prescription were adjusted for age, prior gestational diabetes, parity and diabetes family history. Among 531 patients with complete glucose challenge test data (mean 11.94 mmol/l, sd 1.83), those in the most marginalized neighbourhoods had 0.43 mmol/l higher glucose challenge test values (95% CI 0.08-0.78) compared with the rest of the study population. Other factors associated with higher glucose challenge test values were prior gestational diabetes (0.59 mmol/l increment, 95% CI 0.19-0.99) and diabetes family history (0.32 mmol/l increment, 95% CI -0.01 to 0.66). Each additional 1 mmol/l glucose challenge test result was associated with an increased likelihood of being prescribed insulin (odds ratio 1.33, 95% CI 1.17-1.51). Women living in the most materially deprived and ethnically concentrated neighbourhoods have higher glucose levels at diagnosis of gestational diabetes. They may need close monitoring for timely initiation of insulin. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.

Losartan counteracts the effects of cardiomyocyte swelling on glucose uptake and insulin receptor substrate-1 levels.

PubMed

Gerena, Yamil; Lozada, Janice Griselle; Collazo, Bryan Jael; Méndez-Álvarez, Jarold; Méndez-Estrada, Jennifer; De Mello, Walmor C

2017-10-01

A growing body of evidence demonstrates an association between Angiotensin II (Ang II) receptor blockers (ARBs) and enhanced glucose metabolism during ischemic heart disease. Despite these encouraging results, the mechanisms responsible for these effects during ischemia remain poorly understood. In this study we investigated the influence of losartan, an AT1 receptor blocker, and secreted Ang II (sAng II) on glucose uptake and insulin receptor substrate (IRS-1) levels during cardiomyocyte swelling. H9c2 cells were differentiated to cardiac muscle and the levels of myogenin, Myosin Light Chain (MLC), and membrane AT1 receptors were measured using flow cytometry. Intracellular Ang II (iAng II) was overexpressed in differentiated cardiomyocytes and swelling was induced after incubation with hypotonic solution for 40min. Glucose uptake and IRS-1 levels were monitored by flow cytometry using 2-NBDG fluorescent glucose (10μM) or an anti-IRS-1 monoclonal antibody in the presence or absence of losartan (10 -7 M). Secreted Angiotensin II was quantified from the medium using a specific Ang II-EIA kit. To evaluate the relationship between sAng II and losartan effects on glucose uptake, transfected cells were pretreated with the drug for 24h and then exposed to hypotonic solution in the presence or absence of the secreted peptide. The results indicate that: (1) swelling of transfected cardiomyocytes decreased glucose uptake and induced the secretion of Ang II to the extracellular medium; (2) losartan antagonized the effects of swelling on glucose uptake and IRS-1 levels in transfected cardiomyocytes; (3) the effects of losartan on glucose uptake were observed during swelling only in the presence of sAng II in the culture medium. Our study demonstrates that both losartan and sAng II have essential roles in glucose metabolism during cardiomyocyte swelling. Copyright © 2017 Elsevier Inc. All rights reserved.

Brain extracellular glucose assessed by voltammetry throughout the rat sleep-wake cycle.

PubMed

Netchiporouk, L; Shram, N; Salvert, D; Cespuglio, R

2001-04-01

In the present study, cortical extracellular levels of glucose were monitored for the first time throughout the sleep-wake states of the freely moving rat. For this purpose, polygraphic recordings (electroencephalogram of the fronto-occipital cortices and electromyogram of the neck muscles) were achieved in combination with differential normal pulse voltammetry (DNPV) using a specific glucose sensor. Data obtained reveal that the basal extracellular glucose concentration in the conscious rat is 0.59 +/- 0.3 m M while under chloral hydrate anaesthesia (0.4 g/kg, i.p.) it increases up to 180% of its basal concentration. Regarding the sleep-wake cycle, the existence of spontaneous significant variations in the mean glucose level during slow-wave sleep (SWS = +13%) and paradoxical sleep (PS = -11%) compared with the waking state (100%) is also reported. It is to be noticed that during long periods of active waking, glucose level tends towards a decrease that becomes significant after 15 min (active waking = -32%). On the contrary, during long episodes of slow-wave sleep, it tends towards an increase which becomes significant after 12 min (SWS = +28%). It is suggested that voltammetric techniques using enzymatic biosensors are useful tools allowing direct glucose measurements in the freely moving animal. On the whole, paradoxical sleep is pointed out as a state highly dependent on the availability of energy and slow-wave sleep as a period of energy saving.

Surface Enhanced Raman Spectroscopy for Monitoring Lactate and Glucose

DTIC Science & Technology

2005-07-01

lasers. We have successfully developed and tested these SERS active substances in vitro and in vivo in the subcutaneous space of a rat. Work continues in...using this system for detection in vitro and in vivo as specified in the original proposal. The specific aims, as proposed in the original "statement...assess performance. a. Control experiments. b. Use indwelling probes to quantitatively measure glucose levels in vivo . c. Use indwelling probes to

A comprehensive evaluation of strip performance in multiple blood glucose monitoring systems.

PubMed

Katz, Laurence B; Macleod, Kirsty; Grady, Mike; Cameron, Hilary; Pfützner, Andreas; Setford, Steven

2015-05-01

Accurate self-monitoring of blood glucose is a key component of effective self-management of glycemic control. Accurate self-monitoring of blood glucose results are required for optimal insulin dosing and detection of hypoglycemia. However, blood glucose monitoring systems may be susceptible to error from test strip, user, environmental and pharmacological factors. This report evaluated 5 blood glucose monitoring systems that each use Verio glucose test strips for precision, effect of hematocrit and interferences in laboratory testing, and lay user and system accuracy in clinical testing according to the guidelines in ISO15197:2013(E). Performance of OneTouch(®) VerioVue™ met or exceeded standards described in ISO15197:2013 for precision, hematocrit performance and interference testing in a laboratory setting. Performance of OneTouch(®) Verio IQ™, OneTouch(®) Verio Pro™, OneTouch(®) Verio™, OneTouch(®) VerioVue™ and Omni Pod each met or exceeded accuracy standards for user performance and system accuracy in a clinical setting set forth in ISO15197:2013(E).

Discrepancies Between Blood Glucose and Interstitial Glucose—Technological Artifacts or Physiology: Implications for Selection of the Appropriate Therapeutic Target

PubMed Central

Siegmund, Thorsten; Heinemann, Lutz; Kolassa, Ralf; Thomas, Andreas

2017-01-01

Background: For decades, the major source of information used to make therapeutic decisions by patients with diabetes has been glucose measurements using capillary blood samples. Knowledge gained from clinical studies, for example, on the impact of metabolic control on diabetes-related complications, is based on such measurements. Different to traditional blood glucose measurement systems, systems for continuous glucose monitoring (CGM) measure glucose in interstitial fluid (ISF). The assumption is that glucose levels in blood and ISF are practically the same and that the information provided can be used interchangeably. Thus, therapeutic decisions, that is, the selection of insulin doses, are based on CGM system results interpreted as though they were blood glucose values. Methods: We performed a more detailed analysis and interpretation of glucose profiles obtained with CGM in situations with high glucose dynamics to evaluate this potentially misleading assumption. Results: Considering physical activity, hypoglycemic episodes, and meal-related differences between glucose levels in blood and ISF uncover clinically relevant differences that can make it risky from a therapeutic point of view to use blood glucose for therapeutic decisions. Conclusions: Further systematic and structured evaluation as to whether the use of ISF glucose is more safe and efficient when it comes to acute therapeutic decisions is necessary. These data might also have a higher prognostic relevance when it comes to long-term metabolic consequences of diabetes. In the long run, it may be reasonable to abandon blood glucose measurements as the basis for diabetes management and switch to using ISF glucose as the appropriate therapeutic target. PMID:28322063

Monitoring of Recommended Metabolic Laboratory Parameters Among Medicaid Recipients on Second-Generation Antipsychotics in Federally Qualified Health Centers.

PubMed

Uzal, Natalia E; Chavez, Benjamin; Kosirog, Emily R; Billups, Sarah J; Saseen, Joseph J

2018-02-01

In 2004, a consensus statement outlining recommended metabolic monitoring for patients prescribed second-generation antipsychotics (SGAs) was published. More than a decade later, suboptimal adherence rates to these recommendations continue to be reported, which could lead to long-term and costly complications. To define the prevalence of appropriately monitored Medicaid patients receiving care at federally qualified health centers (FQHCs) prescribed SGAs. This was a retrospective study examining electronic health record and Medicaid claims data to assess the rates of glucose and lipid monitoring for patients prescribed SGAs from January 2014 to August 2016 in a FQHC. Prescription and laboratory claims for patients receiving care at 4 FQHCs were reviewed. Descriptive statistics were used to evaluate the primary outcome. A total of 235 patients were included in the analysis. Patients initiated on SGA therapy (n = 92) had baseline glucose and lipid monitoring rates of 50% and 23%, respectively. The 3-month monitoring rates were 37% for glucose and 26% for lipids, whereas annual rates were 71% and 40%, respectively. Patients continuing SGA therapy (n = 143) had annual glucose and lipid monitoring rates of 67% and 44%. Medicaid patients at FQHCs initially prescribed SGAs have low baseline and 3-month metabolic monitoring, whereas annual monitoring was comparable to previously published studies. Adults receiving chronic care at a FQHC were more likely to receive glucose monitoring. Those with type 2 diabetes mellitus and/or hyperlipidemia were more likely to receive glucose and lipid monitoring.

Sensor and software use for the glycaemic management of insulin-treated type 1 and type 2 diabetes patients.

PubMed

Ajjan, Ramzi A; Abougila, Kamal; Bellary, Srikanth; Collier, Andrew; Franke, Bernd; Jude, Edward B; Rayman, Gerry; Robinson, Anthony; Singh, Baldev M

2016-05-01

Lowering glucose levels, while avoiding hypoglycaemia, can be challenging in insulin-treated patients with diabetes. We evaluated the role of ambulatory glucose profile in optimising glycaemic control in this population. Insulin-treated patients with type 1 and type 2 diabetes were recruited into a prospective, multicentre, 100-day study and randomised to control (n = 28) or intervention (n = 59) groups. The intervention group used ambulatory glucose profile, generated by continuous glucose monitoring, to assess daily glucose levels, whereas the controls relied on capillary glucose testing. Patients were reviewed at days 30 and 45 by the health care professional to adjust insulin therapy. Comparing first and last 2 weeks of the study, ambulatory glucose profile-monitored type 2 diabetes patients (n = 28) showed increased time in euglycaemia (mean ± standard deviation) by 1.4 ± 3.5 h/day (p = 0.0427) associated with reduction in HbA1c from 77 ± 15 to 67 ± 13 mmol/mol (p = 0.0002) without increased hypoglycaemia. Type 1 diabetes patients (n = 25) showed reduction in hypoglycaemia from 1.4 ± 1.7 to 0.8 ± 0.8 h/day (p = 0.0472) associated with a marginal HbA1c decrease from 75 ± 10 to 72 ± 8 mmol/mol (p = 0.0508). Largely similar findings were observed comparing intervention and control groups at end of study. In conclusion, ambulatory glucose profile helps glycaemic management in insulin-treated diabetes patients by increasing time spent in euglycaemia and decreasing HbA1c in type 2 diabetes patients, while reducing hypoglycaemia in type 1 diabetes patients. © The Author(s) 2016.

Use of case-based reasoning to enhance intensive management of patients on insulin pump therapy.

PubMed

Schwartz, Frank L; Shubrook, Jay H; Marling, Cynthia R

2008-07-01

This study was conducted to develop case-based decision support software to improve glucose control in patients with type 1 diabetes mellitus (T1DM) on insulin pump therapy. While the benefits of good glucose control are well known, achieving and maintaining good glucose control remains a difficult task. Case-based decision support software may assist by recalling past problems in glucose control and their associated therapeutic adjustments. Twenty patients with T1DM on insulin pumps were enrolled in a 6-week study. Subjects performed self-glucose monitoring and provided daily logs via the Internet, tracking insulin dosages, work, sleep, exercise, meals, stress, illness, menstrual cycles, infusion set changes, pump problems, hypoglycemic episodes, and other events. Subjects wore a continuous glucose monitoring system at weeks 1, 3, and 6. Clinical data were interpreted by physicians, who explained the relationship between life events and observed glucose patterns as well as treatment rationales to knowledge engineers. Knowledge engineers built a prototypical system that contained cases of problems in glucose control together with their associated solutions. Twelve patients completed the study. Fifty cases of clinical problems and solutions were developed and stored in a case base. The prototypical system detected 12 distinct types of clinical problems. It displayed the stored problems that are most similar to the problems detected, and offered learned solutions as decision support to the physician. This software can screen large volumes of clinical data and glucose levels from patients with T1DM, identify clinical problems, and offer solutions. It has potential application in managing all forms of diabetes.

Translating HbA1c measurements into estimated average glucose values in pregnant women with diabetes.

PubMed

Law, Graham R; Gilthorpe, Mark S; Secher, Anna L; Temple, Rosemary; Bilous, Rudolf; Mathiesen, Elisabeth R; Murphy, Helen R; Scott, Eleanor M

2017-04-01

This study aimed to examine the relationship between average glucose levels, assessed by continuous glucose monitoring (CGM), and HbA 1c levels in pregnant women with diabetes to determine whether calculations of standard estimated average glucose (eAG) levels from HbA 1c measurements are applicable to pregnant women with diabetes. CGM data from 117 pregnant women (89 women with type 1 diabetes; 28 women with type 2 diabetes) were analysed. Average glucose levels were calculated from 5-7 day CGM profiles (mean 1275 glucose values per profile) and paired with a corresponding (±1 week) HbA 1c measure. In total, 688 average glucose-HbA 1c pairs were obtained across pregnancy (mean six pairs per participant). Average glucose level was used as the dependent variable in a regression model. Covariates were gestational week, study centre and HbA 1c . There was a strong association between HbA 1c and average glucose values in pregnancy (coefficient 0.67 [95% CI 0.57, 0.78]), i.e. a 1% (11 mmol/mol) difference in HbA 1c corresponded to a 0.67 mmol/l difference in average glucose. The random effects model that included gestational week as a curvilinear (quadratic) covariate fitted best, allowing calculation of a pregnancy-specific eAG (PeAG). This showed that an HbA 1c of 8.0% (64 mmol/mol) gave a PeAG of 7.4-7.7 mmol/l (depending on gestational week), compared with a standard eAG of 10.2 mmol/l. The PeAG associated with maintaining an HbA 1c level of 6.0% (42 mmol/mol) during pregnancy was between 6.4 and 6.7 mmol/l, depending on gestational week. The HbA 1c -average glucose relationship is altered by pregnancy. Routinely generated standard eAG values do not account for this difference between pregnant and non-pregnant individuals and, thus, should not be used during pregnancy. Instead, the PeAG values deduced in the current study are recommended for antenatal clinical care.

Short term response of insulin, glucose, growth hormone and corticosterone to acute vibration in rats.

NASA Technical Reports Server (NTRS)

Dolkas, C. B.; Leon, H. A.; Chackerian, M.

1971-01-01

Study carried out to obtain some notion of the initial phasing and interactive effects among some hormones known to be responsive to vibration stress. Sprague-Dawley derived rats were exposed to the acute effects of confinement and confinement with lateral (plus or minus G sub y) vibration. The coincident monitoring of glucose, insulin, growth hormone, and corticosterone plasma levels, during and immediately subsequent to exposure to brief low level vibration, exhibits the effects of inhibition of insulin release by epinephrine. The ability of insulin (IRI) to return rapidly to basal levels, from appreciably depressed levels during vibration, in the face of elevated levels of glucose is also shown. Corticosterone responds with almost equal rapidity, but in opposite phase to the IRI. The immuno-assayable growth hormone (IGH) dropped from a basal level of 32 ng/ml to 7.3 ng/ml immediately subsequent to vibration and remained at essentially that level throughout the experiment (60 min). Whether these levels represent a real fall in the rat or whether they merely follow the immuno-logically deficient form is still in question.

Adherence of self-monitoring of blood glucose in persons with type 1 diabetes in Sweden

PubMed Central

Moström, Peter; Ahlén, Elsa; Imberg, Henrik; Hansson, Per-Olof; Lind, Marcus

2017-01-01

Objective The primary aim was to evaluate the extent to which persons with type 1 diabetes perform self-monitoring of blood glucose (SMBG) according to guidelines. Secondary objectives were to investigate predictors for good SMBG adherence, reasons for non-adherence, and association between SMBG frequency and hemoglobin A1c (HbA1c). Methods This was a survey-based cross-sectional study. Questionnaires were sent out to 600 random patients at five sites. Patients were included if they were diagnosed with type 1 diabetes and ≥18 years old and excluded if they were currently using continuous glucose monitoring (CGM). Analysis of data was performed separately for the three sites where the answer frequency was ≥70%. Results In total, 138 of 314 study participants, 43.9% (95% CI 38.5% to 49.4%) performed SMBG ≥4 times per day. For the three clinics where ≥70% of surveyed patients were included in the analysis, results were similar, 41.3% (95% CI 34.7% to 47.8%). Top three reported reasons for not performing more frequent SMBG were lack of time, not remembering, and self-consciousness. Frequency of SMBG was associated with HbA1c levels (p<0.0001). 30% of patients believed that ≤3 SMBG/day was recommended by healthcare providers. Conclusions Less than 50% of patients in Sweden follow guidelines of SMBG ≥4 times per day, despite glucose meters and strips being generally available at no cost. This indicates a need for further support in performing SMBG and increased availability of other tools for glucose monitoring. PMID:28611921

Changes in Serum Adiponectin in Mice Chronically Exposed to Inorganic Arsenic in Drinking Water.

PubMed

Song, Xuanbo; Li, Ying; Liu, Junqiu; Ji, Xiaohong; Zhao, Lijun; Wei, Yudan

2017-09-01

Cardiovascular disease and diabetes mellitus are prominent features of glucose and lipid metabolism disorders. Adiponectin is a key adipokine that is largely involved in glucose and lipid metabolism processes. A growing body of evidence suggests that chronic exposure to inorganic arsenic is associated with cardiovascular disease and diabetes mellitus. We hypothesized that arsenic exposure may increase the risk of cardiovascular disease and diabetes mellitus by affecting the level of adiponectin. In this study, we examined serum adiponectin levels, as well as serum levels of metabolic measures (including fasting blood glucose, insulin, total cholesterol, triglyceride, and high-density lipoprotein (HDL)-cholesterol) in C57BL/6 mice exposed to inorganic arsenic in drinking water (5 and 50 ppm NaAsO 2 ) for 18 weeks. Body mass and adiposity were monitored throughout the study. We found no significant changes in serum insulin and glucose levels in mice treated with arsenic for 18 weeks. However, arsenic exposure decreased serum levels of adiponectin, triglyceride, and HDL-cholesterol. Further, an inverse relationship was observed between urinary concentrations of total arsenic and serum levels of adiponectin. This study suggests that arsenic exposure could disturb the metabolism of lipids and increase the risk of cardiovascular disease by reducing the level of adiponectin.

High glycemic variability assessed by continuous glucose monitoring after surgical treatment of obesity by gastric bypass.

PubMed

Hanaire, Helene; Bertrand, Monelle; Guerci, Bruno; Anduze, Yves; Guillaume, Eric; Ritz, Patrick

2011-06-01

Obesity surgery elicits complex changes in glucose metabolism that are difficult to observe with discontinuous glucose measurements. We aimed to evaluate glucose variability after gastric bypass by continuous glucose monitoring (CGM) in a real-life setting. CGM was performed for 4.2 ± 1.3 days in three groups of 10 subjects each: patients who had undergone gastric bypass and who were referred for postprandial symptoms compatible with mild hypoglycemia, nonoperated diabetes controls, and healthy controls. The maximum interstitial glucose (IG), SD of IG values, and mean amplitude of glucose excursions (MAGE) were significantly higher in operated patients and in diabetes controls than in healthy controls. The time to the postprandial peak IG was significantly shorter in operated patients (42.8 ± 6.0 min) than in diabetes controls (82.2 ± 11.1 min, P = 0.0002), as were the rates of glucose increase to the peak (2.4 ± 1.6 vs. 1.2 ± 0.3 mg/mL/min; P = 0.041). True hypoglycemia (glucose <60 mg/dL) was rare: the symptoms were probably more related to the speed of IG decrease than to the glucose level achieved. Half of the operated patients, mostly those with a diabetes background before surgery, had postprandial glucose concentrations above 200 mg/dL (maximum IG, 306 ± 59 mg/dL), in contrast to the normal glucose concentrations in the fasting state and 2 h postmeal. Glucose variability is exaggerated after gastric bypass, combining unusually high and early hyperglycemic peaks and rapid IG decreases. This might account for postprandial symptoms mimicking hypoglycemia but often seen without true hypoglycemia. Early postprandial hyperglycemia might be underestimated if glucose measurements are done 2 h postmeal.

Progress toward the development of an implantable sensor for glucose.

PubMed

Wilson, G S; Zhang, Y; Reach, G; Moatti-Sirat, D; Poitout, V; Thévenot, D R; Lemonnier, F; Klein, J C

1992-09-01

The development of an electrochemically based implantable sensor for glucose is described. The sensor is needle-shaped, about the size of a 28-gauge needle. It is flexible and must be implanted subcutaneously by using a 21-gauge catheter, which is then removed. When combined with a monitoring unit, this device, based on the glucose oxidase-catalyzed oxidation of glucose, reliably monitors glucose concentrations for as long as 10 days in rats. Various design considerations, including the decision to monitor the hydrogen peroxide produced in the enzymatic reaction, are discussed. Glucose constitutes the most important future target analyte for continuous monitoring, but the basic methodology developed for glucose could be applied to several other analytes such as lactate or ascorbate. The success in implementation of such a device depends on a reaction of the tissue surrounding the implant so as not to interfere with the proper functioning of the sensor. Histochemical evidence indicates that the tissue response leads to enhanced sensor performance.

A 3D paper-based enzymatic fuel cell for self-powered, low-cost glucose monitoring.

PubMed

Fischer, Christopher; Fraiwan, Arwa; Choi, Seokheun

2016-05-15

In this work, we demonstrate a novel low-cost, self-powered paper-based biosensor for glucose monitoring. The device operating mechanism is based on a glucose/oxygen enzymatic fuel cell using an electrochemical energy conversion as a transducing element for glucose monitoring. The self-powered glucose biosensor features (i) a 3D origami paper-based structure for easy system integration onto paper, (ii) an air-cathode on paper for low-cost production and easy operation, and (iii) a screen printed chitosan/glucose oxidase anode for stable current generation as an analytical signal for glucose monitoring. The sensor showed a linear range of output current at 1-5mM glucose (R(2)=0.996) with a sensitivity of 0.02 µA mM(-1). The advantages offered by such a device, including a low cost, lack of external power sources/sophisticated external transducers, and the capacity to rapidly generate reliable results, are well suited for the clinical and social settings of the developing world. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of blood extraction system designed by female mosquito's blood sampling mechanism for bio-MEMS

NASA Astrophysics Data System (ADS)

Tsuchiya, Kazuyoshi; Nakanishi, Naoyuki; Nakamachi, Eiji

2005-02-01

A compact and wearable wristwatch type Bio-MEMS such as a health monitoring system (HMS) to detect blood sugar level for diabetic patient, was newly developed. The HMS consists of (1) a indentation unit with a microneedle to generate the skin penetration force using a shape memory alloy(SMA) actuator, (2) a pumping unit using a bimorph PZT piezoelectric actuator to extract the blood and (3) a gold (Au) electrode as a biosensor immobilized GOx and attached to the gate electrode of MOSFET to detect the amount of Glucose in extracted blood. GOx was immobilized on a self assembled spacer combined with an Au electrode by the cross-link method using BSA as an additional bonding material. The device can extract blood in a few microliter through a painless microneedle with the negative pressure by deflection of the bimorph PZT piezoelectric actuator produced in the blood chamber, by the similar way the female mosquito extracts human blood with muscle motion to flex or relax. The performances of the liquid sampling ability of the pumping unit through a microneedle (3.8mm length, 100μm internal diameter) using the bimorph PZT piezoelectric microactuator were measured. The blood extraction micro device could extract human blood at the speed of 2μl/min, and it is enough volume to measure a glucose level, compared to the amount of commercial based glucose level monitor. The electrode embedded in the blood extraction device chamber could detect electrons generated by the hydrolysis of hydrogen peroxide produced by the reaction between GOx and glucose in a few microliter extracted blood, using the constant electric current measurement system of the MOSFET type hybrid biosensor. The output voltage for the glucose diluted in the chamber was increased lineally with increase of the glucose concentration.

Effect of additional administration of acarbose on blood glucose fluctuations and postprandial hyperglycemia in patients with type 2 diabetes mellitus under treatment with alogliptin.

PubMed

Kusunoki, Yoshiki; Katsuno, Tomoyuki; Myojin, Makiko; Miyakoshi, Kana; Ikawa, Takashi; Matsuo, Toshihiro; Ochi, Fumihiro; Tokuda, Masaru; Murai, Kazuki; Miuchi, Masayuki; Hamaguchi, Tomoya; Miyagawa, Jun-ichiro; Namba, Mitsuyoshi

2013-01-01

Acarbose was administered at 300 mg/day to patients with type 2 diabetes mellitus (T2DM) who had been taking 25 mg/day of alogliptin, and levels of blood glucose were analyzed by continuous glucose monitoring (CGM) for 3 days. The mean blood glucose level with acarbose (136.4 ± 30.7 mg/dL) did not differ significantly from that without acarbose (141.7 ± 28.3 mg/dL). However, in the condition of the combination therapy, there were significant decreases in the standard deviation of the mean blood glucose levels for the 24-hour period (27.6 ± 9.1 vs. 16.2 ± 6.9 mg/dL, p<0.001) and mean amplitude of glycemic excursions (MAGE) (65.8 ± 26.1 vs. 38.8 ± 19.2 mg/dL, p=0.010). In addition, a meal tolerance test was conducted to monitor changes in insulin secretion and active GLP-1 and total GIP values. Ten subjects (5 males, 5 females) of 54.9 ± 6.9 years with BMI 25.9 ± 5.2 kg/m² and HbAlc 9.2 ± 1.2% were enrolled. In the meal tolerance test, active GLP-1 values before and after acarbose administration were 17.0 ± 5.8 and 24.1 ± 9.3 pmol·hr/mL (p=0.054), respectively, showing an increasing tendency, and total GIP(AUC0-180) values were 685.9 ± 209.7 and 404.4 ± 173.7 pmol·hr/mL, respectively, showing a significant decrease (p=0.010). The results indicate that the combined administration of both inhibitors is effective not only in decreasing blood glucose fluctuations and preventing postprandial insulin secretion. The beneficial effects may also protect the endocrine pancreas and inhibit body weight gain.

Blood glucose monitoring during aerobic and anaerobic physical exercise using a new artificial pancreas system.

PubMed

Quirós, Carmen; Bertachi, Arthur; Giménez, Marga; Biagi, Lyvia; Viaplana, Judith; Viñals, Clara; Vehí, Josep; Conget, Ignacio; Bondia, Jorge

To assess an artificial pancreas system during aerobic (AeE) and anaerobic exercise (AnE). A pilot clinical trial on five subjects with type 1 diabetes (4 males) aged 37±10.9 years, diabetes diagnosed 21.2±12.2 years before, insulin pump users, and with a mean HbA 1c level of 7.8±0.5%. Every subject did three AeE and three AnE sessions. Blood glucose levels were monitored by the artificial pancreas system during exercise and up to four hours later. Before the start of exercise, 23g of carbohydrates were administered orally. The mean glucose level was 124.0±25.1mg/dL in the AeE studies and 152.1±34.1mg/dL in the AnE studies. Percent times in the different glucose ranges of 70-180, >180 and <70mg/dL were 89.8±18.6% and 75.9±27.6%; 7.7±18.4% and 23.2±28.0%; and 2.5±6.3% and 1.0±3.6% during the AeE and AnE sessions, respectively. Only six rescues with carbohydrates (15g) were required during the studies (4 in AeE and 2 in AnE). Total insulin dose during the five hours of the study was 3.1±1.0IU in the AeE studies and 3.5±1.3IU in the AnE studies. Blood glucose response to AeE and AnE exercise is different. The evaluated artificial pancreas system appeared to achieve effective and safe blood glucose control during exercise and up to four hours later. However, new control strategies that minimize patient intervention should be designed. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

Windowless ultrasound photoacoustic cell for in vivo mid-IR spectroscopy of human epidermis: Low interference by changes of air pressure, temperature, and humidity caused by skin contact opens the possibility for a non-invasive monitoring of glucose in the interstitial fluid

NASA Astrophysics Data System (ADS)

Pleitez, Miguel A.; Lieblein, Tobias; Bauer, Alexander; Hertzberg, Otto; von Lilienfeld-Toal, Hermann; Mäntele, Werner

2013-08-01

The application of a novel open, windowless cell for the photoacoustic infrared spectroscopy of human skin is described. This windowless cavity is tuned for optimum performance in the ultrasound range between 50 and 60 kHz. In combination with an external cavity tunable quantum cascade laser emitting in the range from ˜1000 cm-1 to 1245 cm-1, this approach leads to high signal-to-noise-ratio (SNR) for mid-infrared spectra of human skin. This opens the possibility to measure in situ the absorption spectrum of human epidermis in the mid-infrared region at high SNR in a few (˜5) seconds. Rapid measurement of skin spectra greatly reduces artifacts arising from movements. As compared to closed resonance cells, the windowless cell exhibits the advantage that the influence of air pressure variations, temperature changes, and air humidity buildup that are caused by the contact of the cell to the skin surface can be minimized. We demonstrate here that this approach can be used for continuous and non-invasive monitoring of the glucose level in human epidermis, and thus may form the basis for a non-invasive monitoring of the glucose level for diabetes patients.

Investigation of pH and temperature on optical rotatory dispersion for noninvasive glucose monitoring

NASA Astrophysics Data System (ADS)

Baba, Justin S.; Meledeo, Adam; Cameron, B. D.; Cote, Gerard L.

2001-06-01

The widespread occurrence of diabetes mellitus and the severity of its associated complications necessitate the development of non-invasive blood glucose measurement devices in an attempt to improve treatment regimens and curb the complications associated with this disease. One method showing promise in this endeavor utilizes optical polarimetry to monitor blood glucose levels indirectly by measuring glucose rotation of polarized light, which is a direct indication of glucose concentration, in the aqueous humor of the eye. The presence of other optically active (chiral) components in the aqueous humor of the eye have the potential to confound the glucose measurement of optical rotation when using a single wavelength polarimeter. Thus, this has led to the recent investigation of multispectral polarimetric systems which have the potential to enable the removal of confounder contributions to the net observed optical rotation, therefore, increasing glucose specificity and reducing glucose prediction errors. Such polarimetric systems take advantage of the uniqueness in the rotation of polarized light, as a function of wavelength, by the chiral molecule of interest. This is commonly referred to as the optical rotatory dispersion (ORD) spectra of the chiral molecule. ORD characterization of the chiral molecules within the aqueous humor is necessary for determining the optimum number of wavelengths needed to reduce glucose prediction errors; however, this information is often only given at the sodium-D line (589 nm) in the literature. This report describes the system we designed and built to measure ORD spectra for glucose and for albumin, the main optical confounder within the aqueous humor, as well as our investigation of the effects of temperature and pH on these ORD spectra.

Robust Brain Hyperglycemia during General Anesthesia: Relationships with Metabolic Brain Inhibition and Vasodilation

PubMed Central

Bola, R. Aaron; Kiyatkin, Eugene A.

2016-01-01

Glucose is the main energetic substrate for the metabolic activity of brain cells and its proper delivery into the extracellular space is essential for maintaining normal neural functions. Under physiological conditions, glucose continuously enters the extracellular space from arterial blood via gradient-dependent facilitated diffusion governed by the GLUT-1 transporters. Due to this gradient-dependent mechanism, glucose levels rise in the brain after consumption of glucose-containing foods and drinks. Glucose entry is also accelerated due to local neuronal activation and neuro-vascular coupling, resulting in transient hyperglycemia to prevent any metabolic deficit. Here, we explored another mechanism that is activated during general anesthesia and results in significant brain hyperglycemia. By using enzyme-based glucose biosensors we demonstrate that glucose levels in the nucleus accumbens (NAc) strongly increase after iv injection of Equthesin, a mixture of chloral hydrate and sodium pentobarbital, which is often used for general anesthesia in rats. By combining electrochemical recordings with brain, muscle, and skin temperature monitoring, we show that the gradual increase in brain glucose occurring during the development of general anesthesia tightly correlate with decreases in brain-muscle temperature differentials, suggesting that this rise in glucose is related to metabolic inhibition. While the decreased consumption of glucose by brain cells could contribute to the development of hyperglycemia, an exceptionally strong positive correlation (r = 0.99) between glucose rise and increases in skin-muscle temperature differentials was also found, suggesting the strong vasodilation of cerebral vessels as the primary mechanism for accelerated entry of glucose into brain tissue. Our present data could explain drastic differences in basal glucose levels found in awake and anesthetized animal preparations. They also suggest that glucose entry into brain tissue could be strongly modulated by pharmacological drugs via drug-induced changes in metabolic activity and the tone of cerebral vessels. PMID:26913008

Development of fluorescent glucose bioprobes and their application on real-time and quantitative monitoring of glucose uptake in living cells.

PubMed

Lee, Hyang Yeon; Lee, Jae Jeong; Park, Jongmin; Park, Seung Bum

2011-01-03

We developed a novel fluorescent glucose bioprobe, GB2-Cy3, for the real-time and quantitative monitoring of glucose uptake in living cells. We synthesized a series of fluorescent glucose analogues by adding Cy3 fluorophores to the α-anomeric position of D-glucose through various linkers. Systematic and quantitative analysis of these Cy3-labeled glucose analogues revealed that GB2-Cy3 was the ideal fluorescent glucose bioprobe. The cellular uptake of this probe competed with the cellular uptake of D-glucose in the media and was mediated by a glucose-specific transport system, and not by passive diffusion. Flow cytometry and fluorescence microscopy analyses revealed that GB2-Cy3 is ten times more sensitive than 2-NBDG, a leading fluorescent glucose bioprobe. GB2-Cy3 can also be utilized for the quantitative flow cytometry monitoring of glucose uptake in metabolically active C2C12 myocytes under various treatment conditions. As opposed to a glucose uptake assay performed by using radioisotope-labeled deoxy-D-glucose and a scintillation counter, GB2-Cy3 allows the real-time monitoring of glucose uptake in living cells under various experimental conditions by using fluorescence microscopy or confocal laser scanning microscopy (CLSM). Therefore, we believe that GB2-Cy3 can be utilized in high-content screening (HCS) for the discovery of novel therapeutic agents and for making significant advances in biomedical studies and diagnosis of various diseases, especially metabolic diseases. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced self-monitoring blood glucose in non-insulin requiring Type 2 diabetes: A qualitative study in primary care.

PubMed

Brackney, Dana Elisabeth

2018-03-31

To contribute to both theoretical and practical understanding of the role of self-monitoring blood glucose for self-management by describing the experience of people with non-insulin requiring Type 2 diabetes in an enhanced structured self-monitoring blood glucose intervention. The complex context of self-monitoring blood glucose in Type 2 diabetes requires a deeper understanding of the clients' illness experience with structured self-monitoring of blood glucose. Clients' numeracy skills contribute to their response to blood glucose readings. Nurses' use of motivational interviewing to increase clients' regulatory self-efficacy is important to the theoretical perspective of the study. A qualitative descriptive study. A purposive sample of eleven adults recently (<2 years) diagnosed with non-insulin requiring Type 2 diabetes who had experienced a structured self-monitoring blood glucose intervention participated in this study. Audio recordings of semi-structured interviews and photos of logbooks were analyzed for themes using constant comparison and member checking. The illness experience states of Type 2 diabetes include 'Diagnosis', 'Behavior change', and 'Routine checking'. People check blood glucose to confirm their Type 2 diabetes diagnosis, to console their diabetes related fears, to create personal explanations of health behavior's impact on blood glucose, to activate behavior change and to congratulate their diabetes self-management efforts. These findings support the Transtheoretical model's stages of change and change processes. Blood glucose checking strengthens the relationships between theoretical concepts found in Diabetes Self-management Education-Support including: engagement, information sharing, and behavioral support. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The albumin-exendin-4 recombinant protein E2HSA improves glycemic control and β-cell function in spontaneous diabetic KKAy mice.

PubMed

Li, Caina; Hou, Shaocong; Liu, Shuainan; Huan, Yi; Sun, Sujuan; Liu, Quan; Shen, Zhufang

2017-06-19

E2HSA is a genetic fusion protein that consists of two tandem exendin-4 molecules that are covalently bonded to recombinant human serum albumin via a peptide linker. Previous studies have demonstrated that E2HSA significantly decreased blood glucose levels, improved β-cell function and promoted β-cell proliferation in diabetic db/dB mice. This study aimed to evaluate the benefits of E2HSA on glucose and lipid metabolism in a spontaneous diabetes animal model, KKAy mice. E2HSA was acutely administered at doses of 1, 3 and 9 mg/kg by subcutaneous injection in diabetic KKAy mice with exendin-4 (2 μg/kg) as a positive reference, and then the non-fasting blood glucose and food intake levels were dynamically monitored. In addition, different doses of E2HSA were injected once daily, as well as with exendin-4 twice daily, for 7 weeks to evaluate the effect on glucose and lipid metabolism, as well as the body weight, food and water intake. Single injection of E2HSA decreased non-fasting blood glucose and food intake levels in a dose-dependent manner for 4 days and 2 days, respectively. Repeated injections with E2HSA significantly decreased variations in blood glucose levels with a reduction of HbA1c levels by 1.6% at a 9 mg/kg dose, simultaneously increased fasting blood insulin levels, inhibited fasting blood glucagon levels, improved the impaired oral glucose tolerance and enhanced glucose infusion rate, which is the gold standard for evaluating β-cell function. Moreover, repeated injections with E2HSA also ameliorated the dyslipidemia and reduced body weight, food and water intake in diabetic KKAy mice. E2HSA significantly reduced blood glucose levels over a prolonged duration, enhanced β-cell function, and ameliorated dyslipidemia and obesity in diabetic KKAy mice. Thus, E2HSA may be a new candidate for the treatment of type 2 diabetes.

A continuous glucose monitoring and problem-solving intervention to change physical activity behavior in women with type 2 diabetes: a pilot study.

PubMed

Allen, Nancy; Whittemore, Robin; Melkus, Gail

2011-11-01

Diabetes technology has the potential to provide useful data for theory-based behavioral counseling. The aims of this study are to evaluate the feasibility, acceptability, and preliminary efficacy of a continuous glucose monitoring and problem-solving counseling intervention to change physical activity (PA) behavior in women with type 2 diabetes. Women (n=29) with type 2 diabetes were randomly assigned to one of two treatment conditions: continuous glucose counseling and problem-solving skills or continuous glucose monitoring counseling and general diabetes education. Feasibility data were obtained on intervention dose, implementation, and satisfaction. Preliminary efficacy data were collected at baseline and 12 weeks on the following measures: PA amount and intensity, diet, problem-solving skills, self-efficacy for PA, depression, hemogoloin A1c, weight, and blood pressure. Demographic and implementation variables were described using frequency distributions and summary statistics. Satisfaction data were analyzed using Wilcoxon rank. Differences between groups were analyzed using linear mixed-modeling. Women were mostly white/non-Latina with a mean age of 53 years, a 6.5-year history of diabetes, and suboptimal glycemic control. Continuous glucose monitoring plus problem-solving group participants had significantly greater problem-solving skills and had greater, although not statistically significant, dietary adherence, moderate activity minutes, weight loss, and higher intervention satisfaction pre- to post-intervention than did participants in the continuous glucose monitoring plus education group. A continuous glucose monitoring plus problem-solving intervention was feasible and acceptable, and participants had greater problem-solving skills than continuous glucose monitoring plus education group participants.

Abnormal glucose levels found in transportation accidents : final report.

DOT National Transportation Integrated Search

2000-06-01

Purpose. The Federal Aviation Administration's Office of Aviation Medicine (OAM) is responsible for the certification of pilots with diabetic conditions. Therefore, it is essential for OAM to monitor pilots involved in fatal accidents for abnormal gl...

Prednisolone

MedlinePlus

... If you have diabetes, prednisolone may increase your blood sugar level. If you monitor your blood sugar (glucose) at home, test your blood or urine ... frequently than usual. Call your doctor if your blood sugar is high.Do not let anyone else take ...

[New developments in the treatment and monitoring of type 1 diabetes mellitus].

PubMed

Otto-Buczkowska, Ewa; Jarosz-Chobot, Przemysława; Tucholski, Krzysztof

2008-01-01

In recent years, insulin analogues are the benefits of the use in functional intensive insulin therapy for the treatment of diabetes. Shortacting insulin (lispro, aspart and glulisine) and long-acting insulin (glargine and detemir) have been developed for the management of diabetes. Short-acting insulin analogues are an alternative to regular human insulin before meals. These new short-acting insulin analogues show more rapid onset of activity and a shorter duration of action. As a result of these pharmacokinetic differences, an improved postprandial glycemic control is achieved, without increasing the risk of hypoglycemia. In addition, these insulin analogues can be administered immediately before a meal. The long-acting insulin analogues provide basal insulin levels for 24 h when administered once (glargine) or two (detemir) daily. Compared with previous intermediate- or long-acting conventional insulin, these insulins shows a flat profile of plasma insulin levels . The use of these long-acting insulin analogues appears to be associated with a reduced incidence of hypoglycemia, especially at night. The availability of these new insulin analogues has the potential to significantly improve long-term control over blood glucose in diabetic patients. In recent years more and more frequently the method of multiple daily injections (MDI) of insulin is being replaced by the method of continuous subcutaneous insulin infusion (CSII). It is the most physiological way to administer insulin. In recent years treatment with insulin pumps has been used more frequently in the pediatric patients and in the treatment of diabetes in pregnancy. Use of continuous glucose monitoring systems enables detection of glycemia fluctuations unrevealed by selfmonitoring of blood glucose, such as night hypoglycemias and early postprandial hyperglycemias. Real-time systems allow to reduce HbA1c levels and limit number of excursions. Non-invasive glucose measurement devices are introduced. Fully automated continuous glucose monitoring systems integrated with insulin pumps operating in closed-loop model, requiring no patient assistance, are still being researched. Commercially available systems operate in open-loop model, where the patient has to decide on administration and dose of insulin.

Toward continuous glucose monitoring with planar modified biosensors and microdialysis. Study of temperature, oxygen dependence and in vivo experiment.

PubMed

Ricci, Francesco; Caprio, Felice; Poscia, Alessandro; Valgimigli, Francesco; Messeri, Dimitri; Lepori, Elena; Dall'Oglio, Giorgio; Palleschi, Giuseppe; Moscone, Danila

2007-04-15

Glucose biosensors based on the use of planar screen-printed electrodes modified with an electrochemical mediator and with glucose oxidase have been optimised for their application in the continuous glucose monitoring in diabetic patients. A full study of their operative stability and temperature dependence has been accomplished, thus giving useful information for in vivo applications. The effect of dissolved oxygen concentration in the working solution was also studied in order to evaluate its effect on the linearity of the sensors. Glucose monitoring performed with serum samples was performed to evaluate the effect of matrix components on operative stability and demonstrated an efficient behaviour for 72 h of continuous monitoring. Finally, these studies led to a sensor capable of detecting glucose at concentrations as low as 0.04 mM and with a good linearity up to 2.0 mM (at 37 degrees C) with an operative stability of ca. 72 h, thus demonstrating the possible application of these sensors for continuous glucose monitoring in conjunction with a microdialysis probe. Moreover, preliminary in vivo experiments for ca. 20 h have demonstrated the feasibility of this system.

Mapping glucose-mediated gut-to-brain signalling pathways in humans.

PubMed

Little, Tanya J; McKie, Shane; Jones, Richard B; D'Amato, Massimo; Smith, Craig; Kiss, Orsolya; Thompson, David G; McLaughlin, John T

2014-08-01

Previous fMRI studies have demonstrated that glucose decreases the hypothalamic BOLD response in humans. However, the mechanisms underlying the CNS response to glucose have not been defined. We recently demonstrated that the slowing of gastric emptying by glucose is dependent on activation of the gut peptide cholecystokinin (CCK1) receptor. Using physiological functional magnetic resonance imaging this study aimed to determine the whole brain response to glucose, and whether CCK plays a central role. Changes in blood oxygenation level-dependent (BOLD) signal were monitored using fMRI in 12 healthy subjects following intragastric infusion (250ml) of: 1M glucose+predosing with dexloxiglumide (CCK1 receptor antagonist), 1M glucose+placebo, or 0.9% saline (control)+placebo, in a single-blind, randomised fashion. Gallbladder volume, blood glucose, insulin, and GLP-1 and CCK concentrations were determined. Hunger, fullness and nausea scores were also recorded. Intragastric glucose elevated plasma glucose, insulin, and GLP-1, and reduced gall bladder volume (an in vivo assay for CCK secretion). Glucose decreased BOLD signal, relative to saline, in the brainstem and hypothalamus as well as the cerebellum, right occipital cortex, putamen and thalamus. The timing of the BOLD signal decrease was negatively correlated with the rise in blood glucose and insulin levels. The glucose+dex arm highlighted a CCK1-receptor dependent increase in BOLD signal only in the motor cortex. Glucose induces site-specific differences in BOLD response in the human brain; the brainstem and hypothalamus show a CCK1 receptor-independent reduction which is likely to be mediated by a circulatory effect of glucose and insulin, whereas the motor cortex shows an early dexloxiglumide-reversible increase in signal, suggesting a CCK1 receptor-dependent neural pathway. Copyright © 2014. Published by Elsevier Inc.

Evaluation of commercial glucometer test strips for potential measurement of glucose in tears.

PubMed

Cha, Kyoung Ha; Jensen, Gary C; Balijepalli, Anant S; Cohan, Bruce E; Meyerhoff, Mark E

2014-02-04

Tear glucose measurements have been suggested as a potential alternative to blood glucose monitoring for diabetic patients. While previous work has reported that there is a correlation between blood and tear glucose levels in humans, this link has not been thoroughly established and additional clinical studies are needed. Herein, we evaluate the potential of using commercial blood glucose test strips to measure glucose in tears. Of several blood glucose strips evaluated, only one brand exhibits the low detection limit required for quantitating glucose in tears. Calibration of these strips in the range of 0-100 μM glucose with an applied potential of 150 mV to the working electrode yields a sensitivity of 0.127 nA/μM and a limit of quantitation (LOQ) of 9 μM. The strips also exhibit ≤13% error (n = 3) for 25, 50, and 75 μM glucose in the presence of 10 μM acetaminophen, 100 μM ascorbic acid, and 100 μM uric acid. Measurements of glucose in tears from nine normal (nondiabetic) fasting human subjects using strips yielded glucose values within the range of 5-148 μM (mean = 47 μM, median = 43 μM), similar to those for human tears reported by others with more complex LC-MS methods. The glucometer strip method could facilitate more clinical studies to determine whether tear glucose and blood glucose levels sufficiently correlate for application to routine measurements in tears to supplement blood glucose testing. This would be especially helpful for children, adolescents, other Type 1 diabetics, and also for Type 2 diabetics who require treatment with insulin and cannot tolerate multiple finger sticks per day.

Identification and prediction of group-based glycemic control trajectories during the transition to adolescence.

PubMed

Rohan, Jennifer M; Rausch, Joseph R; Pendley, Jennifer Shroff; Delamater, Alan M; Dolan, Lawrence; Reeves, Grafton; Drotar, Dennis

2014-10-01

To identify trajectories of glycemic control over a period of 3 years in a pediatric sample of youth diagnosed with Type 1 diabetes transitioning to adolescence. A second aim was to examine a set of modifiable individual and family level baseline predictors of glycemic control group membership. This multisite, prospective study included 239 children and adolescents (ages 9-11 years at baseline) diagnosed with Type 1 diabetes and their caregivers. Glycemic control was based on hemoglobin A1c (HbA1c) collected at 6-month intervals over a period of 3 years. Predictors of glycemic control membership included baseline global executive functioning, diabetes self-management, diabetes-specific family conflict, blood glucose monitoring frequency, and relevant individual and family level covariates. Group-based trajectory analyses were used to describe patterns of glycemic control from baseline to 36 months and 3 trajectories were identified: low risk (42.9%), elevated risk (44.6%), and high risk (12.1%) subgroups. Baseline maternal-reported family conflict, blood glucose monitoring frequency, and gender were significant predictors of glycemic control group membership. Higher levels of baseline family conflict, lower frequency of blood glucose monitoring, and female gender were associated with elevated and high-risk group membership. These findings underscore the importance of examining trajectories of HbA1c across time. These results suggest that problematic trajectories of glycemic control are evident during the transition to adolescence. Furthermore, there are modifiable individual and family level characteristics that predict group membership and hence could be targeted in interventions to ensure adequate glycemic control is maintained over time and that risks for diabetes-related complications are reduced.

Identification and Prediction of Group-Based Glycemic Control Trajectories during the Transition to Adolescence

PubMed Central

Rohan, Jennifer M.; Rausch, Joseph R.; Pendley, Jennifer Shroff; Delamater, Alan M.; Dolan, Lawrence; Reeves, Grafton; Drotar, Dennis

2014-01-01

Objective To identify trajectories of glycemic control over a period of three years in a pediatric sample of youth diagnosed with type 1 diabetes transitioning to adolescence. A second aim was to examine a set of modifiable individual and family-level baseline predictors of glycemic control group membership. Methods This multisite, prospective study included 239 children and adolescents (ages 9–11 years at baseline) diagnosed with type 1 diabetes and their caregivers. Glycemic control was based on hemoglobin A1c (HbA1c) collected at six month intervals over a period of three years. Predictors of glycemic control membership included baseline global executive functioning, diabetes self-management, diabetes-specific family conflict, blood glucose monitoring frequency, and relevant individual and family level covariates. Results Group-based trajectory analyses were used to describe patterns of glycemic control from baseline to 36 months and three trajectories were identified: low risk (42.9%), elevated risk (44.6%), and high risk (12.1%) subgroups. Baseline maternal-reported family conflict, blood glucose monitoring frequency, and gender were significant predictors of glycemic control group membership. Higher levels of baseline family conflict, lower frequency of blood glucose monitoring, and female gender were associated with elevated and high risk group membership. Conclusions These findings underscore the importance of examining trajectories of HbA1c across time. These results suggest that problematic trajectories of glycemic control are evident during the transition to adolescence. Furthermore, there are modifiable individual and family-level characteristics that predict group membership and hence could be targeted in interventions to ensure adequate glycemic control is maintained over time and that risks for diabetes-related complications are reduced. PMID:24274797

Efficacy of sitagliptin on blood glucose fluctuation in Japanese type 2 diabetic patients with basal-supported oral therapy.

PubMed

Takahara, Mitsuyoshi; Shiraiwa, Toshihiko; Kaneto, Hideaki; Katakami, Naoto; Matsuoka, Taka-Aki; Shimomura, Iichiro

2012-01-01

We retrospectively investigated the effect of adding dipeptidyl peptidase-4 (DPP-4) inhibitor and tapering sulfonylurea on blood glucose fluctuation in Asian patients with type 2 diabetes mellitus under basal-supported oral therapy (BOT). We recruited twenty-two consecutive Japanese patients with type 2 diabetes mellitus who had blood glucose fluctuation under the combination therapy of insulin glargine and glimepiride and had sitagliptin initiated with glimepiride tapared. Their hemoglobin A1c levels and mean blood glucose profiles of seven points in self-monitoring blood glucose (SMBG) were 7.4 ± 0.6% and 8.6 ± 2.0 mmol/L, respectively. Sitagliptin was initiated with the dose of 50 mg per day and titrated up to 100 mg per day when necessary. Glimepiride was withdrawn if possible. Blood glucose fluctuation was evaluated with SMBG by calculating M-value, its range (the difference of maximum and minimum blood glucose levels), and its coefficient of variation (CV). Two months after sitagliptin add-on, M-value was decreased from 19 ± 13 to 13 ± 8 (p = 0.04). Blood glucose range and CV were also improved from 9.6 ± 2.9 mmol/L to 7.9 ± 2.6 mmol/L (p = 0.01), and from 33 ± 8% to 29 ± 8% (p < 0.01), respectively. Hemoglobin A1c levels and mean blood glucose profiles were unchanged (p = 0.93 and 0.47). In conclusion, blood glucose fluctuation was significantly improved two months after adding sitagliptin and tapering glimepiride in type 2 diabetic Japanese patients who were treated by BOT with insulin glargine and glimepiride.

New optical scheme for a polarimetric-based glucose sensor

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Bockle, Stefan; Rovati, Luigi

2004-01-01

A new optical scheme to detect glucose concentration in the aqueous humor of the eye is presented. The ultimate aim is to apply this technique in designing a new instrument for, routinely and frequently, noninvasively monitoring blood glucose levels in diabetic patients without contact (no index matching) between the eye and the instrument. The optical scheme exploits the Brewster reflection of circularly polarized light off of the lens of the eye. Theoretically, this reflected linearly polarized light on its way to the detector is expected to rotate its state of polarization, owing to the presence of glucose molecules in the aqueous humor of a patient's eye. An experimental laboratory setup based on this scheme was designed and tested by measuring a range of known concentrations of glucose solutions dissolved in water. (c) 2004 Society of Photo-Optical Instrumentation Engineers.

A high sensitivity MEA probe for measuring real time rat brain glucose flux.

PubMed

Wei, Wenjing; Song, Yilin; Shi, Wentao; Lin, Nansen; Jiang, Tingjun; Cai, Xinxia

2014-05-15

The mammalian central nervous system (CNS) relies on a constant supply of external glucose for its undisturbed operation. This article presents an implantable Multi-Electrode Array (MEA) probe for brain glucose measurement. The MEA was implemented on Silicon-On-Insulator (SOI) wafer using Micro-Electro-Mechanical-Systems (MEMS) methods. There were 16 platinum recording sites on the probe and enzyme glucose oxidase (GOx) was immobilized on them. The glucose sensitivity of the MEA probe was as high as 489 µA mM(-1) cm(-2). 1,3-Phenylenediamine (mPD) was electropolymerized onto the Pt recording surfaces to prevent larger molecules such as ascorbic acid (AA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT), and dopamine (DA) from reaching the recording sites surface. The MEA probe was implanted in the anesthetized rat striatum and responded to glucose levels which were altered by intraperitoneal injection of glucose and insulin. After the in vivo experiment, the MEA probe still kept sensitivity to glucose, these suggested that the MEA probe was reliable for glucose monitoring in brain extracellular fluid (ECF). © 2013 Published by Elsevier B.V.

Self-reported discrimination, diabetes distress, and continuous blood glucose in women with type 2 diabetes.

PubMed

Wagner, Julie A; Tennen, Howard; Feinn, Richard; Osborn, Chandra Y

2015-04-01

We investigated whether self-reported racial discrimination was associated with continuous glucose levels and variability in individuals with diabetes, and whether diabetes distress mediated these associations. Seventy-four Black and White women with type 2 diabetes completed the Experience of Discrimination scale, a measure of lifetime racial discrimination, and the Problem Areas in Diabetes, a measure of diabetes distress. Participants wore a continuous glucose monitor for 24 h after 8 h of fasting, a standard meal, and a 4-h run in period. Higher discrimination predicted higher continuous mean glucose and higher standard deviation of glucose. For both mean and standard deviation of glucose, a race × discrimination interaction indicated a stronger relationship between discrimination and glucose for Whites than for Blacks. Diabetes distress mediated the discrimination-mean glucose relationship. Whites who report discrimination may be uniquely sensitive to distress. These preliminary findings suggest that racial discrimination adversely affects glucose control in women with diabetes, and does so indirectly through diabetes distress. Diabetes distress may be an important therapeutic target to reduce the ill effects of racial discrimination in persons with diabetes.

Early Glucose Derangement Detected by Continuous Glucose Monitoring and Progression of Liver Fibrosis in Nonalcoholic Fatty Liver Disease: An Independent Predictive Factor?

PubMed

Schiaffini, Riccardo; Liccardo, Daniela; Alisi, Anna; Benevento, Danila; Cappa, Marco; Cianfarani, Stefano; Nobili, Valerio

2016-01-01

Glucose derangement has been reported to increase oxidative stress, one of the most important factors underlying the progression of hepatic fibrosis in adults with nonalcoholic fatty liver disease (NAFLD). To date, careful evaluation of the glucose profile in pediatric NAFLD has not been performed. A total of 30 severely obese children (15 males; mean age 12.87 ± 2.19 years) with biopsy-proven NAFLD were enrolled in this study from September to December 2013. All patients underwent anthropometric and laboratory evaluation, including the oral glucose tolerance test (OGTT) and continuous glucose monitoring (CGM). Our study reveals some differences between OGTT and CGM in detecting NAFLD children with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). OGTT showed 2 (6.67%) patients with IFG and 1 (3.34%) with IGT, while CGM showed 5 (16.67%) patients with IFG and 6 (20%) with IGT. The daily blood glucose profile positively correlated with the baseline blood glucose (r = 0.39, p = 0.04) and the homeostatic model assessment (r = 0.56, p = 0.05). A positive correlation between hyperglycemia and liver fibrosis was found (r = 0.65, p < 0.05). Mean glucose values (F3-F4 group: 163.2 ± 35.92 mg/dl vs. F1 group: 136.58 ± 46.83 mg/dl and F2 group: 154.12 ± 22.51 mg/dl) and the difference between the minimum and maximum blood glucose levels (F3-F4 group: 110.21 ± 25.26 mg/dl vs. F1 group: 91.67 ± 15.97 mg/dl and F2 group: 92 ± 15.48 mg/dl) were significantly (p < 0.05) higher in the F3-F4 group compared to the F1 and F2 groups. Glucose profile derangement as detected by CGM is associated with the severity of hepatic fibrosis in children with NAFLD. © 2015 S. Karger AG, Basel.

Effectiveness of Medium-Chain Triglyceride Oil Therapy in Two Japanese Citrin-Deficient Siblings: Evaluation Using Oral Glucose Tolerance Tests.

PubMed

Otsuka, Hiroki; Sasai, Hideo; Abdelkreem, Elsayed; Kawamoto, Norio; Kawamoto, Minako; Kamiya, Toshiya; Tanimoto, Yasuo; Kikuchi, Atsuo; Kure, Shigeo; Numakura, Chikahiko; Hayasaka, Kiyoshi; Fukao, Toshiyuki

2016-12-01

Citrin deficiency, an inherited defect of the liver-type mitochondrial aspartate/glutamate carrier isoform (citrin), may cause impairment of glycolysis because of an increase in the cytosolic NADH/NAD + ratio. We report a Japanese boy whose main complaint was recurrent hypoglycemic episodes. He was suspected as having citrin deficiency because of his peculiar preference for protein- and fat-rich food. His young sister also had a similar food preference. Both siblings were diagnosed with citrin deficiency by genetic analysis. The brother and sister underwent an oral glucose tolerance test (OGTT) at 10 and 7 yr of age, respectively. Blood glucose, ammonia, lactic acid, pyruvic acid, and insulin levels were monitored before starting the test, and then every 30 min. During this test, they maintained blood glucose levels until 180 min. At 210 min, they experienced vomiting, feeling ill, and decreased blood glucose levels (2.9 and 2.8 mmol/l in the brother and sister, respectively). The sister and brother recovered uneventfully by intravenous glucose injection. In a second OGTT, 4 months after medium-chain triglyceride (MCT) oil supplementation, they had no major symptoms and normal glucose levels were maintained, even after 240 min. Additionally, after MCT oil therapy, their food preference slightly changed as they started eating more carbohydrates. Our OGTT data suggest excess carbohydrate intake has adverse consequences in patients with citrin deficiency, including hypoglycemia after a few hours. MCT oil therapy may be effective in preventing such hypoglycemia and improving metabolic derangement, even during the so-called apparently healthy period.

The effect of gold nanoparticles modified electrode on the glucose sensing performance

NASA Astrophysics Data System (ADS)

Zulkifli, Zulfa Aiza; Ridhuan, Nur Syafinaz; Nor, Noorhashimah Mohamad; Zakaria, Nor Dyana; Razak, Khairunisak Abdul

2017-07-01

In this work, 20 nm, 30 nm, 40 nm, 50 nm and 60 nm colloidal gold nanoparticles (AuNPs) were synthesized using the seeding growth method. AuNPs produced had spherical shape with uniform size. The AuNPs also are well dispersed in colloidal form that was proven by low polydispersity index. The produced AuNPs were used to modify electrode for glucose sensor. The produced AuNPs were deposited on indium tin oxide substrate (ITO), followed by immobilization of glucose oxidase (GOx) on it. After that, Nafion was deposited on the GOx/AuNPs/ITO. Electrooxidation of glucose with AuNPs-modified electrode was examined by cyclic voltammeter (CV) in 15 mM glucose mixed with 0.01 M PBS. The optimum size of AuNPs was 30 nm with optical density 3.0. AuNPs were successfully immobilized with glucose oxidase (GOx) and proved to work well as a glucose sensor. Based on the high electrocatalytic activity of Nafion/GOx/AuNPs/ITO, the sensitivity of the glucose sensors was further examined by varying the concentration of glucose solution from 2 mM to 20 mM in 0.01 M phosphate buffer solution (PBS) solution. Good linear relationship was observed between the catalytic current and glucose concentration in the range of 2 mM to 20 mM. The sensitivity of the Nafion/GOx/AuNPs/ITO electrode calculated from the slope of linear square calibration was 0.909 µA mM-1 cm-2 that is comparable with other published work. The linear fitting to the experimental data gives R-square of 0.991 at 0.9 V and a detection limit of 2.03 mM. This detection range is sufficient to be medically useful in monitoring human blood glucose level in which the normal blood glucose level is in the range of 4.4 to 6.6 mM and diabetic blood glucose level is above 7 mM.

Effect of Glycemic Control on Chylomicron Metabolism and Correlation between Postprandial Metabolism of Plasma Glucose and Chylomicron in Patients with Type 2 Diabetes Treated with Basal-bolus Insulin Therapy with or without Vildagliptin

PubMed Central

Emoto, Naoya; Kato, Katsuhito; Sugihara, Hitoshi

2017-01-01

Aim: Glucagon-like peptide-1 can reduce both postprandial plasma glucose (PG) and chylomicron (CM) levels in patients with type 2 diabetes. However, there have been no reports regarding the relationship between the postprandial metabolism of PG and CM. Methods: Patients with type 2 diabetes who were admitted for glycemic control were randomized to insulin alone (Ins; n = 16) or insulin plus vildagliptin 100 mg (InsV; n = 16) groups. The insulin dose was adjusted to maintain normal blood glucose levels. The daily profiles of serum TG, remnant lipoprotein cholesterol (RemL-C), and apolipoprotein B48 (ApoB48) were estimated by frequent blood collection on admission and before discharge, and the daily glucose fluctuation profile was also estimated using continuous glucose monitoring (CGM) before discharge. Results: The daily profiles of serum TG and RemL-C indicated a significant decrease before discharge compared with on admission; however, no significant changes in serum ApoB48 levels were observed in either group. At discharge, daily glucose fluctuation profile and the change in the serum ApoB48 level from fasting to the peak of the daily profile was significantly smaller in the InsV group than in the Ins group. The increment of serum ApoB48 level was significantly correlated with the mean amplitude of glycemic excursions calculated using CGM data only in the Ins group (R2 = 0.5242, P <0.001). Conclusions: Short-term glycemic control decreased serum TG and RemL-C levels, but not ApoB48 levels, and the postprandial metabolism of PG and CM might be regulated by the same mechanism except GLP-1 effect. PMID:27397060

Effect of Glycemic Control on Chylomicron Metabolism and Correlation between Postprandial Metabolism of Plasma Glucose and Chylomicron in Patients with Type 2 Diabetes Treated with Basal-bolus Insulin Therapy with or without Vildagliptin.

PubMed

Okajima, Fumitaka; Emoto, Naoya; Kato, Katsuhito; Sugihara, Hitoshi

2017-02-01

Glucagon-like peptide-1 can reduce both postprandial plasma glucose (PG) and chylomicron (CM) levels in patients with type 2 diabetes. However, there have been no reports regarding the relationship between the postprandial metabolism of PG and CM. Patients with type 2 diabetes who were admitted for glycemic control were randomized to insulin alone (Ins; n=16) or insulin plus vildagliptin 100 mg (InsV; n=16) groups. The insulin dose was adjusted to maintain normal blood glucose levels. The daily profiles of serum TG, remnant lipoprotein cholesterol (RemL-C), and apolipoprotein B48 (ApoB48) were estimated by frequent blood collection on admission and before discharge, and the daily glucose fluctuation profile was also estimated using continuous glucose monitoring (CGM) before discharge. The daily profiles of serum TG and RemL-C indicated a significant decrease before discharge compared with on admission; however, no significant changes in serum ApoB48 levels were observed in either group. At discharge, daily glucose fluctuation profile and the change in the serum ApoB48 level from fasting to the peak of the daily profile was significantly smaller in the InsV group than in the Ins group. The increment of serum ApoB48 level was significantly correlated with the mean amplitude of glycemic excursions calculated using CGM data only in the Ins group (R 2 = 0.5242,P＜0.001). Short-term glycemic control decreased serum TG and RemL-C levels, but not ApoB48 levels, and the postprandial metabolism of PG and CM might be regulated by the same mechanism except GLP-1 effect.

Influence of the blood glucose level on the development of retinopathy of prematurity in extremely premature children.

PubMed

Nicolaeva, Galina V; Sidorenko, Evgenyj I; Iosifovna, Amkhanitskaya Lyubov

2015-01-01

To investigate the influence of the blood glucose level on the development of retinopathy of prematurity (ROP) in extremely premature infants. Sixty-four premature infants with a gestational age of less than 30 weeks and a birth weight of less than 1500 g were included in the study. Children without ROP were allocated to Group 1 (n=14, gestational age 28.6 ± 1.4 weeks, birth weight 1162 ± 322 g), and children with spontaneous regression of ROP were allocated to Group 2 (n=32, gestational age 26.5 ± 1.2 weeks, birth weight 905 ± 224 g). Children with progressive ROP who underwent laser treatment were included in Group 3 (n=18, gestational age 25.4 ± 0.7 weeks, birth weight 763 ± 138 g). The glucose level in the capillary blood of the premature infants was monitored daily during the first 3 weeks of life. A complete ophthalmological screening was performed from the age of 1 month. The nonparametric signed-rank Wilcoxon-Mann-Whitney test was used for statistical analysis. The mean blood glucose level was 7.43 ± 2.6 mmol/L in Group 1, 7.8 ± 2.7 mmol/L in Group 2, and 6.7 ± 2.6 mmol/L in Group 3. There were no significant differences in the blood glucose levels between children with and without ROP, and also between children with spontaneously regressing ROP and progressive ROP (p>0.05). Additionally, there were no significant differences in the blood glucose levels measured at the first, second, and third weeks of life (p>0.05). The blood glucose level is not related to the development of ROP nor with its progression or regression. The glycemic level cannot be considered as a risk factor for ROP, but reflects the severity of newborns' somatic condition and morphofunctional immaturity.

Sensing interstitial glucose to nudge active lifestyles (SIGNAL): feasibility of combining novel self-monitoring technologies for persuasive behaviour change

PubMed Central

Kingsnorth, Andrew P; Orme, Mark W; Sherar, Lauren B; Esliger, Dale W

2017-01-01

Introduction Increasing physical activity (PA) reduces the risk of developing diabetes, highlighting the role of preventive medicine approaches. Changing lifestyle behaviours is difficult and is often predicated on the assumption that individuals are willing to change their lifestyles today to reduce the risk of developing disease years or even decades later. The self-monitoring technologies tested in this study will present PA feedback in real time, parallel with acute physiological data. Presenting the immediate health benefits of being more physically active may help enact change by observing the immediate consequences of that behaviour. The present study aims to assess user engagement with the self-monitoring technologies in individuals at moderate-to-high risk of developing type 2 diabetes. Methods and analysis 45 individuals with a moderate-to-high risk, aged ≥40 years old and using a compatible smartphone, will be invited to take part in a 7-week protocol. Following 1 week of baseline measurements, participants will be randomised into one of three groups: group 1— glucose feedback followed by biobehavioural feedback (glucose plus PA); group 2—PA feedback followed by biobehavioural feedback; group 3—biobehavioural feedback. A PA monitor and a flash glucose monitor will be deployed during the intervention. Participants will wear both devices throughout the intervention but blinded to feedback depending on group allocation. The primary outcome is the level of participant engagement and will be assessed by device use and smartphone usage. Feasibility will be assessed by the practicality of the technology and screening for diabetes risk. Semistructured interviews will be conducted to explore participant experiences using the technologies. Trial registration number ISRCTN17545949. Registered on 15/05/2017. PMID:28993396

Loss of Hfe Leads to Progression of Tumor Phenotype in Primary Retinal Pigment Epithelial Cells

PubMed Central

Gnana-Prakasam, Jaya P.; Veeranan-Karmegam, Rajalakshmi; Coothankandaswamy, Veena; Reddy, Sushma K.; Martin, Pamela M.; Thangaraju, Muthusamy; Smith, Sylvia B.; Ganapathy, Vadivel

2013-01-01

Purpose. Hemochromatosis is a disorder of iron overload arising mostly from mutations in HFE. HFE is expressed in retinal pigment epithelium (RPE), and Hfe−/− mice develop age-related iron accumulation and retinal degeneration associated with RPE hyperproliferation. Here, the mechanism underlying the hyperproliferative phenotype in RPE was investigated. Methods. Cellular senescence was monitored by β-galactosidase activity. Gene expression was monitored by real-time PCR. Survivin was analyzed by Western blot and immunofluorescence. Migration and invasion were monitored using appropriate kits. Glucose transporters (GLUTs) were monitored by 3-O-methyl-D-glucose uptake. Histone deacetylases (HDACs) were studied by monitoring catalytic activity and acetylation status of histones H3/H4. Results. Hfe−/− RPE cells exhibited slower senescence rate and higher survivin expression than wild type cells. Hfe−/− cells migrated faster and showed greater glucose uptake and increased expression of GLUTs. The expression of HDACs and DNA methyltransferase (DNMTs) also was increased. Similarly, RPE cells from hemojuvelin (Hjv)-knockout mice, another model of hemochromatosis, also had increased expression of GLUTs, HDACs, and DNMTs. The expression of Slc5a8 was decreased in Hfe−/− RPE cells, but treatment with a DNA methylation inhibitor restored the transporter expression, indicating involvement of DNA methylation in the silencing of Slc5a8 in Hfe−/− cells. Conclusions. RPE cells from iron-overloaded mice exhibit several features of tumor cells: decreased senescence, enhanced migration, increased glucose uptake, and elevated levels of HDACs and DNMTs. These features are seen in Hfe−/− RPE cells as well as in Hjv−/− RPE cells, providing a molecular basis for the hyperproliferative phenotype of Hfe−/− and Hjv−/− RPE cells. PMID:23169885

Therapeutics of diabetes mellitus: focus on insulin analogues and insulin pumps.

PubMed

Valla, Vasiliki

2010-01-01

Inadequately controlled diabetes accounts for chronic complications and increases mortality. Its therapeutic management aims in normal HbA1C, prandial and postprandial glucose levels. This review discusses diabetes management focusing on the latest insulin analogues, alternative insulin delivery systems and the artificial pancreas. Intensive insulin therapy with multiple daily injections (MDI) allows better imitation of the physiological rhythm of insulin secretion. Longer-acting, basal insulin analogues provide concomitant improvements in safety, efficacy and variability of glycaemic control, followed by low risks of hypoglycaemia. Continuous subcutaneous insulin infusion (CSII) provides long-term glycaemic control especially in type 1 diabetic patients, while reducing hypoglycaemic episodes and glycaemic variability. Continuous subcutaneous glucose monitoring (CGM) systems provide information on postprandial glucose excursions and nocturnal hypo- and/or hyperglycemias. This information enhances treatment options, provides a useful tool for self-monitoring and allows safer achievement of treatment targets. In the absence of a cure-like pancreas or islets transplants, artificial "closed-loop" systems mimicking the pancreatic activity have been also developed. Individualized treatment plans for insulin initiation and administration mode are critical in achieving target glycaemic levels. Progress in these fields is expected to facilitate and improve the quality of life of diabetic patients.

Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform

DOE PAGES

Emaminejad, Sam; Gao, Wei; Wu, Eric; ...

2017-04-17

Perspiration-based wearable biosensors facilitate continuous monitoring of individuals' health states with real-time and molecular-level insight. The inherent inaccessibility of sweat in sedentary individuals in large volume (≥10 μL) for on-demand and in situ analysis has limited our ability to capitalize on this noninvasive and rich source of information. A wearable and miniaturized iontophoresis interface is an excellent solution to overcome this barrier. The iontophoresis process involves delivery of stimulating agonists to the sweat glands with the aid of an electrical current. The challenge remains in devising an iontophoresis interface that can extract sufficient amount of sweat for robust sensing, withoutmore » electrode corrosion and burning/causing discomfort in subjects. Here, we overcame this challenge through realizing an electrochemically enhanced iontophoresis interface, integrated in a wearable sweat analysis platform. This interface can be programmed to induce sweat with various secretion profiles for real-time analysis, a capability which can be exploited to advance our knowledge of the sweat gland physiology and the secretion process. To demonstrate the clinical value of our platform, human subject studies were performed in the context of the cystic fibrosis diagnosis and preliminary investigation of the blood/sweat glucose correlation. With our platform, we detected the elevated sweat electrolyte content of cystic fibrosis patients compared with that of healthy control subjects. Furthermore, our results indicate that oral glucose consumption in the fasting state is followed by increased glucose levels in both sweat and blood. In conclusion, our solution opens the possibility for a broad range of noninvasive diagnostic and general population health monitoring applications.« less

[Effectiveness and economic impact of a program of integrated care with telemedicine support on insulin-treated type 2 diabetic patients (Study GITDIABE)].

PubMed

Inoriza, Jose M; Ibañez, Annabel; Pérez-Berruezo, Xavier; Inoriza-Nadal, Cristina; Coderch, Jordi

2017-03-01

To evaluate if insulin-treated type 2 diabetic patients with blood glucose self-monitoring (DIA), included in a program of integrated management of diabetes mellitus (DM), achieve a better level of metabolic control with telemedicine support than with conventional support, after 12 months follow-up. The impact on the use and cost of healthcare services, pharmaceutical expenditure, and consumption of test strips for blood glucose, was also assessed. A prospective parallel cohorts study. Four basic health areas of an integrated healthcare organisation. The study included 126 DIA patients aged 15 or more years, treated with rapid or intermediate Insulin and blood glucose self-monitoring, grouped into 42 cases and 84 controls, matched according to age, sex, level of metabolic control, and morbidity profile. Telematics physician-patient communication and download of blood glucose self-monitoring data through the Emminens eConecta ® platform; test strips home delivered according to consumption. Hidden controls with usual follow-up. Glycosylated haemoglobin (%HbA1c); perception of quality of life (EuroQol-5 and EsDQOL); cardiovascular risk; use of healthcare resources; consumption of test strips; pharmaceutical and healthcare expenditure. Reduction of 0.38% in HbA1c in the cases (95% CI:-0.89% to 0.12%). No significant differences with regard to any of the activities registered, or any significant change in the quality of life. The results obtained are similar to other equivalent studies. The profile of the patient is elderly and with multiple morbidities, who still have technological limitations. To surpass these barriers, it would be necessary to devote more time to the training and to the resolution of possible technological problems. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform

PubMed Central

Emaminejad, Sam; Gao, Wei; Wu, Eric; Davies, Zoe A.; Yin Yin Nyein, Hnin; Challa, Samyuktha; Ryan, Sean P.; Fahad, Hossain M.; Chen, Kevin; Shahpar, Ziba; Talebi, Salmonn; Milla, Carlos; Javey, Ali; Davis, Ronald W.

2017-01-01

Perspiration-based wearable biosensors facilitate continuous monitoring of individuals’ health states with real-time and molecular-level insight. The inherent inaccessibility of sweat in sedentary individuals in large volume (≥10 µL) for on-demand and in situ analysis has limited our ability to capitalize on this noninvasive and rich source of information. A wearable and miniaturized iontophoresis interface is an excellent solution to overcome this barrier. The iontophoresis process involves delivery of stimulating agonists to the sweat glands with the aid of an electrical current. The challenge remains in devising an iontophoresis interface that can extract sufficient amount of sweat for robust sensing, without electrode corrosion and burning/causing discomfort in subjects. Here, we overcame this challenge through realizing an electrochemically enhanced iontophoresis interface, integrated in a wearable sweat analysis platform. This interface can be programmed to induce sweat with various secretion profiles for real-time analysis, a capability which can be exploited to advance our knowledge of the sweat gland physiology and the secretion process. To demonstrate the clinical value of our platform, human subject studies were performed in the context of the cystic fibrosis diagnosis and preliminary investigation of the blood/sweat glucose correlation. With our platform, we detected the elevated sweat electrolyte content of cystic fibrosis patients compared with that of healthy control subjects. Furthermore, our results indicate that oral glucose consumption in the fasting state is followed by increased glucose levels in both sweat and blood. Our solution opens the possibility for a broad range of noninvasive diagnostic and general population health monitoring applications. PMID:28416667

Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emaminejad, Sam; Gao, Wei; Wu, Eric

Perspiration-based wearable biosensors facilitate continuous monitoring of individuals' health states with real-time and molecular-level insight. The inherent inaccessibility of sweat in sedentary individuals in large volume (≥10 μL) for on-demand and in situ analysis has limited our ability to capitalize on this noninvasive and rich source of information. A wearable and miniaturized iontophoresis interface is an excellent solution to overcome this barrier. The iontophoresis process involves delivery of stimulating agonists to the sweat glands with the aid of an electrical current. The challenge remains in devising an iontophoresis interface that can extract sufficient amount of sweat for robust sensing, withoutmore » electrode corrosion and burning/causing discomfort in subjects. Here, we overcame this challenge through realizing an electrochemically enhanced iontophoresis interface, integrated in a wearable sweat analysis platform. This interface can be programmed to induce sweat with various secretion profiles for real-time analysis, a capability which can be exploited to advance our knowledge of the sweat gland physiology and the secretion process. To demonstrate the clinical value of our platform, human subject studies were performed in the context of the cystic fibrosis diagnosis and preliminary investigation of the blood/sweat glucose correlation. With our platform, we detected the elevated sweat electrolyte content of cystic fibrosis patients compared with that of healthy control subjects. Furthermore, our results indicate that oral glucose consumption in the fasting state is followed by increased glucose levels in both sweat and blood. In conclusion, our solution opens the possibility for a broad range of noninvasive diagnostic and general population health monitoring applications.« less

FRET-based glucose imaging identifies glucose signalling in response to biotic and abiotic stresses in rice roots.

PubMed

Zhu, Qingdong; Wang, Li; Dong, Qianli; Chang, Shu; Wen, Kexin; Jia, Shenghua; Chu, Zhilin; Wang, Hanmeng; Gao, Ping; Zhao, Heping; Han, Shengcheng; Wang, Yingdian

2017-08-01

Glucose is the primary energy provider and the most important sugar-signalling molecule, regulating metabolites and modulating gene expression from unicellular yeast to multicellular plants and animals. Therefore, monitoring intracellular glucose levels temporally and spatially in living cells is an essential step for decoding the glucose signalling in response to biotic and abiotic stresses. In this study, the genetically encoded FRET (Förster resonance energy transfer) nanosensors, FLIPglu-2μ∆13 and FLIPglu-600μΔ13, were used to measure cytosolic glucose dynamics in rice plants. First, we found that the FRET signal decreased in response to external glucose in a concentration-dependent manner. The glucose concentration at which the cytosolic level corresponded to the K 0.5 value for FLIPglu-2μΔ13 was approximately 10.05μM, and that for FLIPglu-600μΔ13 was 0.9mM, respectively. The substrate selectivity of nanosensors for glucose and its analogues is D-Glucose>2-deoxyglucose>3-O-methylglucose>L-Glucose. We further showed that the biotic elicitors (flg22 and chitin) and the abiotic elicitors (osmotic stress, salinity and extreme temperature) induce the intracellular glucose increases in the detached root segments of transgenic rice containing FLIPglu-2μΔ13 in a stimulus-specific manner, but not in FLIPglu-600μΔ13 transgenic lines. These results demonstrated that FRET nanosensors can be used to detect increases in intracellular glucose within the physiological range of 0.2-20μM in response to various stimuli in transgenic rice root cells, which indicated that intracellular glucose may act as a potential secondary messenger to connect extracellular stimuli with cellular physiological responses in plants. Copyright © 2017 Elsevier GmbH. All rights reserved.

Diabetes Treatment Breakthrough.

ERIC Educational Resources Information Center

Baker, Shelly; And Others

1993-01-01

Eight experts in visual impairment respond briefly to reports that intensive monitoring of blood glucose levels by persons with diabetes can lead to a 70% reduction in the progression of detectable diabetic retinopathy. Comments are generally optimistic, though some cautions are raised. (DB)

Optical coherence tomography for glucose monitoring in blood

NASA Astrophysics Data System (ADS)

Ullah, Hafeez; Hussain, Fayyaz; Ikram, Masroor

2015-08-01

In this review, we have discussed the potential application of the emerging imaging modality, i.e., optical coherence tomography (OCT) for glucose monitoring in biological tissues. OCT provides monitoring of glucose diffusion in different fibrous tissues like in sclera by determining the permeability rate with acceptable accuracy both in type 1 and in type 2 diabetes. The maximum precision of glucose measurement in Intralipid suspensions, for example, with the OCT technique yields the accuracy up to 4.4 mM for 10 % Intralipid and 2.2 mM for 3 % Intralipid.

Monitoring blood glucose levels in female mink during the reproductive cycle: 2. Effects of short-term fish oil, chromium picolinate, and acetylsalicylic acid supplementation during late lactation

PubMed Central

Hynes, Amber M.J.; Rouvinen-Watt, Kirsti

2007-01-01

Mink nursing sickness is a metabolic disorder characterized by hyperglycemia that is similar to the metabolic syndrome associated with type 2, or non-insulin-dependent, diabetes mellitus. This research studied the effects of short-term administration of antidiabetic supplements on the blood glucose concentration in female mink during late lactation. Female mink that had blood glucose levels < 5.5 mmol/L (normoglycemic [NG]) or ≥ 5.5 mmol/L (hyperglycemic [HG]) early in lactation were given daily supplements of various combinations of herring oil (HerO, 3% in diet), chromium picolinate (CrPic, 200 μg), and acetylsalicylic acid (ASA, 100 mg) for 1 wk starting at day 21 post partum. In the NG mink, most of the treatments did not significantly change the blood glucose concentration from day 28 to 42 post partum. However, treatment with ASA alone and treatment with the combination HerO-CrPic-ASA elevated the blood glucose levels when compared with those of the control group, which had received just the basal diet. In the HG mink, all treatment combinations except CrPic alone and ASA alone, reduced the blood glucose concentration. Thus, in lactating mink with hyperglycemia, the blood glucose concentration may be effectively lowered by dietary antidiabetic supplementation; however, because hyperglycemia also occurs before nursing, preventive measures are recommended throughout the year. PMID:17955898

Glucose excursions and glycaemic control during Ramadan fasting in diabetic patients: insights from continuous glucose monitoring (CGM).

PubMed

Lessan, N; Hannoun, Z; Hasan, H; Barakat, M T

2015-02-01

Ramadan fasting represents a major shift in meal timing and content for practicing Muslims. This study used continuous glucose monitoring (CGM) to assess changes in markers of glycaemic excursions during Ramadan fasting to investigate the short-term safety of this practice in different groups of patients with diabetes. A total of 63 subjects (56 with diabetes, seven healthy volunteers; 39 male, 24 female) had CGM performed during, before and after Ramadan fasting. Mean CGM curves were constructed for each group for these periods that were then used to calculate indicators of glucose control and excursions. Post hoc data analyses included comparisons of different medication categories (metformin/no medication, gliptin, sulphonylurea and insulin). Medication changes during Ramadan followed American Diabetes Association guidelines. Among patients with diabetes, there was a significant difference in mean CGM curve during Ramadan, with a slow fall during fasting hours followed by a rapid rise in glucose level after the sunset meal (iftar). The magnitude of this excursion was greatest in the insulin-treated group, followed by the sulphonylurea-treated group. Markers of control deteriorated in a small number (n=3) of patients. Overall, whether fasting or non-fasting, subjects showed no statistically significant changes in mean interstitial glucose (IG), mean amplitude of glycaemic excursion (MAGE), high and low blood glucose indices (HBGI/LBGI), and number of glucose excursions and rate of hypoglycaemia. The main change in glycaemic control with Ramadan fasting in patients with diabetes is in the pattern of excursions. Ramadan fasting caused neither overall deterioration nor improvement in the majority of patients with good baseline glucose control. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

1H-MRSI pattern perturbation in a mouse glioma: the effects of acute hyperglycemia and moderate hypothermia.

PubMed

Simões, R V; Delgado-Goñi, T; Lope-Piedrafita, S; Arús, C

2010-01-01

MR spectroscopic Imaging (MRSI), with PRESS localization, is used here to monitor the effects of acute hyperglycemia in the spectral pattern of 11 mice bearing GL261 gliomas at normothermia (36.5-37.5 degrees C) and at hypothermia (28.5-29.5 degrees C). These in vivo studies were complemented by ex vivo high resolution magic angle spinning (HR-MAS) analysis of GL261 tumor samples from 6 animals sacrificed by focused microwave irradiation, and blood glucose measurements in 12 control mice. Apparent glucose levels, monitored by in vivo MRSI in brain tumors during acute hyperglycemia, rose to an average of 1.6-fold during hypothermia (p < 0.05), while no significant changes were detected at normothermia, or in control experiments performed at euglycemia, or in normal/peritumoral brain regions. Ex vivo analysis of glioma-bearing mouse brains at hypothermia revealed higher glucose increases in distinct regions during the acute hyperglycemic challenge (up to 6.6-fold at the tumor center), in agreement with maximal in vivo blood glucose changes (5-fold). Phantom studies on taurine plus glucose containing solutions explained the differences between in vivo and ex vivo measurements. Our results also indicate brain tumor heterogeneity in the four animal tumors investigated in response to a defined metabolic challenge.

Calibration Experiments Conducted for Noninvasive Blood Glucose Sensing Through the Eye

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Bockle, Stefan; Suh, Kwang I.; Rovati, Luigi L.

2004-01-01

There are more than 16 million diabetics in the United States and more than 100 million worldwide. Diabetes can lead to severe complications over time such as blindness, renal and cardiovascular diseases, and peripheral neuropathy in the limbs. Poor blood circulation in diabetics can lead to gangrene and the subsequent amputation of extremities. In addition, this pathology is the fourth leading cause of death in the United States. The most effective way to manage diabetes is frequent blood glucose monitoring performed by the patients themselves. However, because of pain, inconvenience, and the fear of developing infections from finger-prick blood tests or implants, many patients monitor their blood glucose levels less frequently than is recommended by their physicians. Therefore, a noninvasive, painless, and convenient method to monitor blood glucose would greatly benefit diabetics. Likewise, detecting, preventing, and treating the untoward effects of prolonged space travel (e.g., a human mission to Mars) in real-time requires the development of noninvasive diagnostic technologies that are compact and powerful. As a "window to the body," the eye offers the opportunity to use light in various forms to detect ocular and systemic abnormalities long before clinical symptoms appear and to help develop preventative and therapeutic countermeasures early. The noninvasive feature of these technologies permits frequent repetition of tests, enabling an evaluation of the response to therapy.

A Post-Marketing Surveillance Study to Evaluate Performance of the EXIMO™ Blood Glucose Monitoring System.

PubMed

Chandnani, Sonia R; Ramakrishna, C D; Dave, Bhargav A; Kothavade, Pankaj S; Thakkar, Ashok S

2017-05-01

The performance of Blood Glucose Monitoring System (BGMS) is critical as the information provided by the system guide the patient or health care professional in making treatment decisions. However, besides evaluating accuracy of the BGMS in laboratory setting, it is equally important that the intended users (healthcare professionals and patients) should be able to achieve blood glucose measurements with similar level of high accuracy. To assess the performance of EXIMO™ (Meril Diagnostics Pvt. Ltd., Vapi, Gujarat, India) BGMS as per International Organization for Standardization (ISO) 15197:2013 section 8 user performance criteria. This was a non-randomized and post-marketing study conducted at a tertiary care centre of India. A total of 1005 patients with diabetes themselves performed fingertip blood glucose measurement using EXIMO™ BGMS. Immediately after capillary blood glucose measurement using the blood glucose monitoring system, venous blood sample from each patient was obtained by a trained technician which was assessed by reference laboratory method- Cobas Integra 400 plus (Roche Instrument Centre, Rotkreuz, Switzerland). All the blood glucose measurements assessed by EXIMO™ were compared with laboratory results. Performance of the system was assessed as per ISO 15197:2013 criteria using Bland-Altman plot, Parkes-Consensus Error Grid (CEG) and Surveillance Error Grid analyses (SEG). A total of 1005 patients participated in the study. Average age of the patients was 44.93±14.65 years. Evaluation of capillary fingertip blood glucose measurements demonstrated that 95.82% measurements fulfilled ISO 15197:2013 section 8 user performance criteria. All the results lie within clinically non-critical zones; Zone A (99.47%; n=1000) and Zone B (0.53%; n=05) of the CEG analysis. As per SEG analysis, majority of the results fell within "no-risk" zone (risk score 0 to 0.5; 90.42%). The result of the study confirmed that intended users are able to obtain accurate glucose measurements when operating EXIMO™ BGMS, given only the instructions and training materials routinely provided with the system, in clinical practice.

A Post-Marketing Surveillance Study to Evaluate Performance of the EXIMO™ Blood Glucose Monitoring System

PubMed Central

Chandnani, Sonia R.; Ramakrishna, C. D.; Dave, Bhargav A.; Kothavade, Pankaj S.

2017-01-01

Introduction The performance of Blood Glucose Monitoring System (BGMS) is critical as the information provided by the system guide the patient or health care professional in making treatment decisions. However, besides evaluating accuracy of the BGMS in laboratory setting, it is equally important that the intended users (healthcare professionals and patients) should be able to achieve blood glucose measurements with similar level of high accuracy. Aim To assess the performance of EXIMO™ (Meril Diagnostics Pvt. Ltd., Vapi, Gujarat, India) BGMS as per International Organization for Standardization (ISO) 15197:2013 section 8 user performance criteria. Materials and Methods This was a non-randomized and post-marketing study conducted at a tertiary care centre of India. A total of 1005 patients with diabetes themselves performed fingertip blood glucose measurement using EXIMO™ BGMS. Immediately after capillary blood glucose measurement using the blood glucose monitoring system, venous blood sample from each patient was obtained by a trained technician which was assessed by reference laboratory method- Cobas Integra 400 plus (Roche Instrument Centre, Rotkreuz, Switzerland). All the blood glucose measurements assessed by EXIMO™ were compared with laboratory results. Performance of the system was assessed as per ISO 15197:2013 criteria using Bland-Altman plot, Parkes-Consensus Error Grid (CEG) and Surveillance Error Grid analyses (SEG). Results A total of 1005 patients participated in the study. Average age of the patients was 44.93±14.65 years. Evaluation of capillary fingertip blood glucose measurements demonstrated that 95.82% measurements fulfilled ISO 15197:2013 section 8 user performance criteria. All the results lie within clinically non-critical zones; Zone A (99.47%; n=1000) and Zone B (0.53%; n=05) of the CEG analysis. As per SEG analysis, majority of the results fell within “no-risk” zone (risk score 0 to 0.5; 90.42%). Conclusion The result of the study confirmed that intended users are able to obtain accurate glucose measurements when operating EXIMO™ BGMS, given only the instructions and training materials routinely provided with the system, in clinical practice. PMID:28658800

Long-Term Home Study on Nocturnal Hypoglycemic Alarms Using a New Fully Implantable Continuous Glucose Monitoring System in Type 1 Diabetes.

PubMed

Wang, Xiaolin; Ioacara, Sorin; DeHennis, Andrew

2015-11-01

This study analyzed the overall nocturnal performance during home use of a long-term subcutaneous implantable continuous glucose monitoring (CGM) sensor. In this study, 12 subjects with type 1 diabetes mellitus (T1DM) (mean±SD age, 37±8 years; mean±SD disease duration, 11±6 years) were implanted with an investigational continuous glucose sensor in the upper arm for up to 90 days. All subjects received full access to real-time glucose display and user programmable hypo- and hyperglycemic alarms. Subjects calibrated the sensors with a self-monitoring of blood glucose (SMBG) meter and continued to rely on their regular SMBG measurements for their diabetes management. Accuracy of the sensors during the home-use study was calculated using SMBG as the reference. The nocturnal sensor attenuation (NSA) concept was tested. Sensitivity and specificity of the nocturnal hypoglycemic alarm were calculated. Mean±SD glucose sensor life span was 87±7 days. The mean±SE absolute relative difference over the range of 40-400 mg/dL for the sensors in this home-use study was 12.3±0.7% using SMBG as the reference. The hypoglycemia alarms were set to be triggered when the glucose level went below 70 mg/dL. Percentage of nights with hypoglycemic alarms triggered for at least 10 min was 13.6%. Recovery into euglycemia within 30 min from the timestamp of the immediate confirmatory SMBG testing was obtained in 74% of all episodes (n=20). The implanted continuous glucose sensor showed a hypoglycemia detection sensitivity and specificity of 77% and 96%, respectively. The NSA-associated high negative rate of change of at least -4 mg/dL/min was not encountered during night use of the system. This home-use study of a fully implantable, long-term continuous glucose sensor shows excellent performance in nocturnal hypoglycemia detection in T1DM patients. The apparent lack of NSA affecting the implanted sensor and the high specificity of the hypoglycemic alarm expedite the recovery from nighttime hypoglycemia.

Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics

PubMed Central

Kim, Joohee; Kim, Minji; Lee, Mi-Sun; Kim, Kukjoo; Ji, Sangyoon; Kim, Yun-Tae; Park, Jihun; Na, Kyungmin; Bae, Kwi-Hyun; Kyun Kim, Hong; Bien, Franklin; Young Lee, Chang; Park, Jang-Ung

2017-01-01

Wearable contact lenses which can monitor physiological parameters have attracted substantial interests due to the capability of direct detection of biomarkers contained in body fluids. However, previously reported contact lens sensors can only monitor a single analyte at a time. Furthermore, such ocular contact lenses generally obstruct the field of vision of the subject. Here, we developed a multifunctional contact lens sensor that alleviates some of these limitations since it was developed on an actual ocular contact lens. It was also designed to monitor glucose within tears, as well as intraocular pressure using the resistance and capacitance of the electronic device. Furthermore, in-vivo and in-vitro tests using a live rabbit and bovine eyeball demonstrated its reliable operation. Our developed contact lens sensor can measure the glucose level in tear fluid and intraocular pressure simultaneously but yet independently based on different electrical responses. PMID:28447604

Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics.

PubMed

Kim, Joohee; Kim, Minji; Lee, Mi-Sun; Kim, Kukjoo; Ji, Sangyoon; Kim, Yun-Tae; Park, Jihun; Na, Kyungmin; Bae, Kwi-Hyun; Kyun Kim, Hong; Bien, Franklin; Young Lee, Chang; Park, Jang-Ung

2017-04-27

Wearable contact lenses which can monitor physiological parameters have attracted substantial interests due to the capability of direct detection of biomarkers contained in body fluids. However, previously reported contact lens sensors can only monitor a single analyte at a time. Furthermore, such ocular contact lenses generally obstruct the field of vision of the subject. Here, we developed a multifunctional contact lens sensor that alleviates some of these limitations since it was developed on an actual ocular contact lens. It was also designed to monitor glucose within tears, as well as intraocular pressure using the resistance and capacitance of the electronic device. Furthermore, in-vivo and in-vitro tests using a live rabbit and bovine eyeball demonstrated its reliable operation. Our developed contact lens sensor can measure the glucose level in tear fluid and intraocular pressure simultaneously but yet independently based on different electrical responses.

Wearable smart sensor systems integrated on soft contact lenses for wireless ocular diagnostics

NASA Astrophysics Data System (ADS)

Kim, Joohee; Kim, Minji; Lee, Mi-Sun; Kim, Kukjoo; Ji, Sangyoon; Kim, Yun-Tae; Park, Jihun; Na, Kyungmin; Bae, Kwi-Hyun; Kyun Kim, Hong; Bien, Franklin; Young Lee, Chang; Park, Jang-Ung

2017-04-01

Wearable contact lenses which can monitor physiological parameters have attracted substantial interests due to the capability of direct detection of biomarkers contained in body fluids. However, previously reported contact lens sensors can only monitor a single analyte at a time. Furthermore, such ocular contact lenses generally obstruct the field of vision of the subject. Here, we developed a multifunctional contact lens sensor that alleviates some of these limitations since it was developed on an actual ocular contact lens. It was also designed to monitor glucose within tears, as well as intraocular pressure using the resistance and capacitance of the electronic device. Furthermore, in-vivo and in-vitro tests using a live rabbit and bovine eyeball demonstrated its reliable operation. Our developed contact lens sensor can measure the glucose level in tear fluid and intraocular pressure simultaneously but yet independently based on different electrical responses.

Continuous non-invasive blood glucose monitoring by spectral image differencing method

NASA Astrophysics Data System (ADS)

Huang, Hao; Liao, Ningfang; Cheng, Haobo; Liang, Jing

2018-01-01

Currently, the use of implantable enzyme electrode sensor is the main method for continuous blood glucose monitoring. But the effect of electrochemical reactions and the significant drift caused by bioelectricity in body will reduce the accuracy of the glucose measurements. So the enzyme-based glucose sensors need to be calibrated several times each day by the finger-prick blood corrections. This increases the patient's pain. In this paper, we proposed a method for continuous Non-invasive blood glucose monitoring by spectral image differencing method in the near infrared band. The method uses a high-precision CCD detector to switch the filter in a very short period of time, obtains the spectral images. And then by using the morphological method to obtain the spectral image differences, the dynamic change of blood sugar is reflected in the image difference data. Through the experiment proved that this method can be used to monitor blood glucose dynamically to a certain extent.

Ultrahigh-viscosity hydroxypropylmethylcellulose blunts postprandial glucose after a breakfast meal in women.

PubMed

Dow, Shireen; Pritchett, Kelly L; Hawk, Susan; Herrington, Stefanie J; Gee, David L

2012-04-01

To determine the effects of two water-soluble dietary fibers, ultrahigh-viscosity hydroxypropylmethylcellulose (UHV-HPMC, nonfermentable) and psyllium fiber (fermentable), on postprandial glucose and second meal effects. In a single-blind crossover design, 12 healthy adult subjects were given standardized, premeasured breakfast and lunch meals with either 4 g of the fiber supplements or a placebo. Blood glucose was measured with a continuous blood glucose monitoring system (DexCom Seven Plus, San Diego, CA). Subjects consuming UHV-HPMC had significantly (p < 0.05) lower blood glucose area under the curve (AUC) 2 hours after breakfast than those receiving a placebo. Subjects consuming psyllium also tended to have lower glucose levels than the placebo group. Peak glucose concentration following breakfast was significantly (p < 0.01) less with UHV-HPMC when compared with the placebo. No significant differences in AUC or peak glucose concentration between treatments following the second meal (lunch) were detected, suggesting no residual effect from the fiber supplements. Supplementation with viscous water-soluble fibers may be an effective means of reducing the glycemic response of a meal in healthy adults.

Effects of temperature on the near-infrared spectroscopic measurement of glucose

NASA Astrophysics Data System (ADS)

Jung, Byungjo; McShane, Michael J.; Rastegar, Sohi; Cote, Gerard L.

1998-05-01

The noninvasive monitoring of sugars, and in particular, glucose using near-IR (NIR) spectroscopy would be useful for a number of applications including regulating the nutrients in cell culture medium, monitoring on-line processes in the food industry, and in vivo monitoring for control of glucose in DIabetic patients. The focus of this research was the investigation of the temperature effects across a 10.6 to 40.4 degrees C range on Fourier filtered and unfiltered single-beam as well as absorbance glucose and water NIR spectra. It is known that the positions of water absorption bands centered at 1.923 and 2.623 micrometers depend heavily on temperature effects while the glucose bands are temperature insensitive across this range. The water absorption bands were shown to shift to lower wavelengths while the distance between these bands increased with increasing temperatures. Partial least squares (PLS) calibration models were constructed at five separate temperatures, 15.7, 20.5, 25.5, 35.6, and 40.4 degrees C. When absorbance spectra were used with reference scans taken at the same temperature and PLS models were used, no significant difference in the standard error of prediction (SEP) was noted with temperature. Using PLS calibration with single-beam spectra at one temperature showed large SEPs at the other temperatures. The use of Fourier filtered single-beam spectra reduced the SEP but still showed an increase as large temperature differences were produced and the filtered single beam approach did not reduce the SEP to the level achieved with the absorbance spectra.

Effect of eating vegetables before carbohydrates on glucose excursions in patients with type 2 diabetes

PubMed Central

Imai, Saeko; Fukui, Michiaki; Kajiyama, Shizuo

2014-01-01

The aim of this review was to evaluate whether eating vegetables before carbohydrates could reduce the postprandial glucose, insulin, and improve long-term glycemic control in Japanese patients with type 2 diabetes. We studied the effect of eating vegetables before carbohydrates on postprandial plasma glucose, insulin, and glycemic control for 2.5 y in patients with type 2 diabetes. The postprandial glucose and insulin levels decreased significantly when the patients ate vegetables before carbohydrates compared to the reverse regimen, and the improvement of glycemic control was observed for 2.5 y. We also compared the postprandial glucose and glucose fluctuations assessed by continuous glucose monitoring system for 72-h in patients with type 2 diabetes and subjects with normal glucose tolerance when subjects ate vegetables before carbohydrates and carbohydrates before vegetables in a randomized crossover design. The glycemic excursions and incremental glucose peak were significantly lower when the subjects ate vegetables before carbohydrates compared to the reverse regimen. This evidence supports the effectiveness of eating vegetables before carbohydrates on glucose excursions in the short-term and glycemic control in the long-term in patients with type 2 diabetes. PMID:24426184

Effect of eating vegetables before carbohydrates on glucose excursions in patients with type 2 diabetes.

PubMed

Imai, Saeko; Fukui, Michiaki; Kajiyama, Shizuo

2014-01-01

The aim of this review was to evaluate whether eating vegetables before carbohydrates could reduce the postprandial glucose, insulin, and improve long-term glycemic control in Japanese patients with type 2 diabetes. We studied the effect of eating vegetables before carbohydrates on postprandial plasma glucose, insulin, and glycemic control for 2.5 y in patients with type 2 diabetes. The postprandial glucose and insulin levels decreased significantly when the patients ate vegetables before carbohydrates compared to the reverse regimen, and the improvement of glycemic control was observed for 2.5 y. We also compared the postprandial glucose and glucose fluctuations assessed by continuous glucose monitoring system for 72-h in patients with type 2 diabetes and subjects with normal glucose tolerance when subjects ate vegetables before carbohydrates and carbohydrates before vegetables in a randomized crossover design. The glycemic excursions and incremental glucose peak were significantly lower when the subjects ate vegetables before carbohydrates compared to the reverse regimen. This evidence supports the effectiveness of eating vegetables before carbohydrates on glucose excursions in the short-term and glycemic control in the long-term in patients with type 2 diabetes.

Dual-Modulation, Dual-Wavelength, Optical Polarimetry System for Glucose Monitoring

DTIC Science & Technology

2016-08-26

dual-wavelength, optical polarimetry system for glucose monitoring 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) 5d...JBO.21.8.087001] 14. ABSTRACT A dual modulation optical polarimetry system utilizing both laser intensity and polarization modulation was designed...varying birefringence, which is one of the major limitations to the realization of polarimetry for glucose monitoring in the eye. The high-speed less

Evaluation of a Non-Invasive Alternative Glucose Monitor System in Patients with Diabetes Mellitus

DTIC Science & Technology

2008-01-07

Diabetes Mellitus New Protocol Title: Evaluation of a Non-Invasive Alternative Glucose Monitor System in Patients with Diabetes Mellitus PRINCIPAL...Invasive Alternative Glucose Monitor System in Patients with Diabetes Mellitus 5b. GRANT NUMBER Coop Agreement # 05216002 5c. PROGRAM ELEMENT NUMBER...Flexible Medical Systems was approved by the Department of Clinical Investigation at WRAMC in January 2008. FY08 AAMTI funding will support the

Can gingival crevicular blood be relied upon for assessment of blood glucose level?

PubMed

Dwivedi, Shivani; Verma, Sharmila J; Shah, Monali; Jain, Kapil

2014-11-01

Diabetes mellitus (DM) is undiagnosed in approximately half of the patients actually suffering from the disease. In addition, the prevalence of DM is more than twice as high as in patients with periodontitis when compared to periodontally healthy subjects. Thus, a high number of patients with periodontitis may have undiagnosed DM. The purpose of the present study was to evaluate whether blood oozing from a gingival crevice during routine periodontal examination can be used for determining glucose levels. Observational cross-sectional studies were carried out in 75 patients (43 males and 32 females) with chronic periodontitis who were divided into two groups: Group I and Group II, respectively. Blood oozing from the gingival crevices of anterior teeth following periodontal probing was collected with the stick of glucose self-monitoring device, and the blood glucose levels were measured. At the same time, finger-prick blood was taken for glucometric analysis and subsequent readings were recorded. The patient's blood glucose values ranged from 74 to 256 mg/dl. The comparison between gingival crevicular blood and finger-prick blood showed a very strong correlation, with a t value of 3.97 (at P value = 0.001). The data from this study has shown that GCB collected during diagnostic periodontal examination can be an excellent source of blood for glucometric analysis.

[Metabolic control in the critically ill patient an update: hyperglycemia, glucose variability hypoglycemia and relative hypoglycemia].

PubMed

Pérez-Calatayud, Ángel Augusto; Guillén-Vidaña, Ariadna; Fraire-Félix, Irving Santiago; Anica-Malagón, Eduardo Daniel; Briones Garduño, Jesús Carlos; Carrillo-Esper, Raúl

Metabolic changes of glucose in critically ill patients increase morbidity and mortality. The appropriate level of blood glucose has not been established so far and should be adjusted for different populations. However concepts such as glucose variability and relative hypoglycemia of critically ill patients are concepts that are changing management methods and achieving closer monitoring. The purpose of this review is to present new data about the management and metabolic control of patients in critical areas. Currently glucose can no longer be regarded as an innocent element in critical patients; both hyperglycemia and hypoglycemia increase morbidity and mortality of patients. Protocols and better instruments for continuous measurement are necessary to achieve the metabolic control of our patients. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Non-invasive method to detect the changes of glucose concentration in whole blood using photometric technique.

PubMed

Rajan, Shiny Amala Priya; Towe, Bruce C

2014-01-01

A non-invasive method is developed to monitor rapid changes in blood glucose levels in diabetic patients. The system depends on an optical cell built with a LED that emits light of wavelength 535nm, which is a peak absorbance of hemoglobin. As the glucose concentration in blood decreases, its osmolarity also decreases and the Red Blood Cells (RBCs) swell and decrease the path length absorption coefficient. Decreasing absorption coefficient increases the transmission of light through the whole blood. The system was tested with a constructed optical cell that held whole blood in a capillary tube. As expected the light transmitted to the photodiode increases with decreasing glucose concentration. The average response time of the system was between 30-40 seconds.

Single-Walled Carbon Nanotube-Based Near-Infrared Optical Glucose Sensors toward In Vivo Continuous Glucose Monitoring

PubMed Central

Yum, Kyungsuk; McNicholas, Thomas P.; Mu, Bin; Strano, Michael S.

2013-01-01

This article reviews research efforts on developing single-walled carbon nanotube (SWNT)-based near-infrared (NIR) optical glucose sensors toward long-term in vivo continuous glucose monitoring (CGM). We first discuss the unique optical properties of SWNTs and compare SWNTs with traditional organic and nanoparticle fluorophores regarding in vivo glucose-sensing applications. We then present our development of SWNT-based glucose sensors that use glucose-binding proteins and boronic acids as a high-affinity molecular receptor for glucose and transduce binding events on the receptors to modulate SWNT fluorescence. Finally, we discuss opportunities and challenges in translating the emerging technology of SWNT-based NIR optical glucose sensors into in vivo CGM for practical clinical use. PMID:23439162

Visualizing Sweetness: Increasingly Diverse Applications for Fluorescent-Tagged Glucose Bioprobes and Their Recent Structural Modifications

PubMed Central

Kim, Woong Hee; Lee, Jinho; Jung, Da-Woon; Williams, Darren R.

2012-01-01

Glucose homeostasis is a fundamental aspect of life and its dysregulation is associated with important diseases, such as cancer and diabetes. Traditionally, glucose radioisotopes have been used to monitor glucose utilization in biological systems. Fluorescent-tagged glucose analogues were initially developed in the 1980s, but it is only in the past decade that their use as a glucose sensor has increased significantly. These analogues were developed for monitoring glucose uptake in blood cells, but their recent applications include tracking glucose uptake by tumor cells and imaging brain cell metabolism. This review outlines the development of fluorescent-tagged glucose analogues, describes their recent structural modifications and discusses their increasingly diverse biological applications. PMID:22666073

The effect of intra-articular triamcinolone preparations on blood glucose levels in diabetic patients: a controlled study.

PubMed

Habib, George S; Miari, Walid

2011-09-01

The objective of the study was to evaluate the effect of intra-articular (IA) triamcinolone hexacetonide (TAH) and triamcinolone acetonide (TA) on blood glucose levels in patients with controlled diabetes with symptomatic osteoarthritis of the knee (OAK). Patients with controlled diabetes with symptomatic OAK who failed nonsteroidal anti-inflammatory medication and physical therapy and use modern versions of self-monitoring blood glucose devices were offered an IA injection of either 20 mg of TAH or 40 mg of TA. If agreed, patients were asked to document blood glucose levels before and 2 hr after meals for 1 week before and daily for 5 days then every other day for 1 week following the injection. The type of IA preparation was given on an alternating pattern. A sex- and aged-matched group of patients with controlled diabetes with symptomatic OAK of the knee was offered an IA hyaluronic acid (HA) injection. Significantly increased blood glucose level following the IA injection was defined as higher by at least 2 SDs than the mean comparable level before the injection. Thirty patients completed the study: 12 patients in the TAH, 12 patients in the TA group, and 6 in the HA group. All the patients who received triamcinolone preparations had significantly increased blood glucose levels with median initial levels of 227.5 and 201 mg% seen at a median of 8.5 and 13 hr following the IA injection and median peak levels of 288 and 239.5 mg% seen after a median of 24.5 and 32.5 hr following the IA injection of TA and TAH, respectively. Levels returned to normal after ∼2.5 to ∼4 days. There was no significant increase in the HA group except in 1 measurement only with marginal level in 2 patients. Intra-articular injection of either TAH or TA is associated with significantly increased blood glucose levels in patients with controlled diabetes with OAK. This increase is quite solely due to the injected steroids.

Effects of two doses of glucose and a caffeine-glucose combination on cognitive performance and mood during multi-tasking.

PubMed

Scholey, Andrew; Savage, Karen; O'Neill, Barry V; Owen, Lauren; Stough, Con; Priestley, Caroline; Wetherell, Mark

2014-09-01

This study assessed the effects of two doses of glucose and a caffeine-glucose combination on mood and performance of an ecologically valid, computerised multi-tasking platform. Following a double-blind, placebo-controlled, randomised, parallel-groups design, 150 healthy adults (mean age 34.78 years) consumed drinks containing placebo, 25 g glucose, 60 g glucose or 60 g glucose with 40 mg caffeine. They completed a multi-tasking framework at baseline and then 30 min following drink consumption with mood assessments immediately before and after the multi-tasking framework. Blood glucose and salivary caffeine were co-monitored. The caffeine-glucose group had significantly better total multi-tasking scores than the placebo or 60 g glucose groups and were significantly faster at mental arithmetic tasks than either glucose drink group. There were no significant treatment effects on mood. Caffeine and glucose levels confirmed compliance with overnight abstinence/fasting, respectively, and followed the predicted post-drink patterns. These data suggest that co-administration of glucose and caffeine allows greater allocation of attentional resources than placebo or glucose alone. At present, we cannot rule out the possibility that the effects are due to caffeine alone Future studies should aim at disentangling caffeine and glucose effects. © 2014 The Authors. Human Psychopharmacology: Clinical and Experimental published by John Wiley & Sons, Ltd.

Effects of two doses of glucose and a caffeine–glucose combination on cognitive performance and mood during multi-tasking

PubMed Central

Scholey, Andrew; Savage, Karen; O'Neill, Barry V; Owen, Lauren; Stough, Con; Priestley, Caroline; Wetherell, Mark

2014-01-01

Background This study assessed the effects of two doses of glucose and a caffeine–glucose combination on mood and performance of an ecologically valid, computerised multi-tasking platform. Materials and methods Following a double-blind, placebo-controlled, randomised, parallel-groups design, 150 healthy adults (mean age 34.78 years) consumed drinks containing placebo, 25 g glucose, 60 g glucose or 60 g glucose with 40 mg caffeine. They completed a multi-tasking framework at baseline and then 30 min following drink consumption with mood assessments immediately before and after the multi-tasking framework. Blood glucose and salivary caffeine were co-monitored. Results The caffeine–glucose group had significantly better total multi-tasking scores than the placebo or 60 g glucose groups and were significantly faster at mental arithmetic tasks than either glucose drink group. There were no significant treatment effects on mood. Caffeine and glucose levels confirmed compliance with overnight abstinence/fasting, respectively, and followed the predicted post-drink patterns. Conclusion These data suggest that co-administration of glucose and caffeine allows greater allocation of attentional resources than placebo or glucose alone. At present, we cannot rule out the possibility that the effects are due to caffeine alone Future studies should aim at disentangling caffeine and glucose effects. PMID:25196040

[A non-invasive portable blood-glucose monitoring system: sampling of suction effusion fluid].

PubMed

Arai, T; Kayashima, S; Kikuchi, M; Kaneyoshi, A; Itoh, N

1995-04-01

We developed a new portable transcutaneous blood glucose monitoring system using non-invasive collection of suction effusion fluid (SEF) from human skin. A ion sensitive field effect transistor (ISFET) sensor was employed to measure glucose concentration in a very small quantity of the SEF. The system was composed of a couple of portions. One structure was a suction cell, and the other was a main frame. The suction cell included the ISFET glucose sensor, a dilution mechanism, and a sucking interface to human skin. The main frame contained a dilution solution reservoir, a liquid waste reservoir, a fluid pump, a vacuum pump, a micro processor, batteries, and a user interface. The system is self-contained for portable usage during up to 6 hrs monitoring. This system may be the first blood glucose monitoring equipment which does not use blood sampling.

The effect of rising vs. falling glucose level on amperometric glucose sensor lag and accuracy in Type 1 diabetes.

PubMed

Ward, W K; Engle, J M; Branigan, D; El Youssef, J; Massoud, R G; Castle, J R

2012-08-01

Because declining glucose levels should be detected quickly in persons with Type 1 diabetes, a lag between blood glucose and subcutaneous sensor glucose can be problematic. It is unclear whether the magnitude of sensor lag is lower during falling glucose than during rising glucose. Initially, we analysed 95 data segments during which glucose changed and during which very frequent reference blood glucose monitoring was performed. However, to minimize confounding effects of noise and calibration error, we excluded data segments in which there was substantial sensor error. After these exclusions, and combination of data from duplicate sensors, there were 72 analysable data segments (36 for rising glucose, 36 for falling). We measured lag in two ways: (1) the time delay at the vertical mid-point of the glucose change (regression delay); and (2) determination of the optimal time shift required to minimize the difference between glucose sensor signals and blood glucose values drawn concurrently. Using the regression delay method, the mean sensor lag for rising vs. falling glucose segments was 8.9 min (95%CI 6.1-11.6) vs. 1.5 min (95%CI -2.6 to 5.5, P<0.005). Using the time shift optimization method, results were similar, with a lag that was higher for rising than for falling segments [8.3 (95%CI 5.8-10.7) vs. 1.5 min (95% CI -2.2 to 5.2), P<0.001]. Commensurate with the lag results, sensor accuracy was greater during falling than during rising glucose segments. In Type 1 diabetes, when noise and calibration error are minimized to reduce effects that confound delay measurement, subcutaneous glucose sensors demonstrate a shorter lag duration and greater accuracy when glucose is falling than when rising. © 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.

Metabolic effects of propranolol and hydroflumethiazide treatment in Kenyans with mild to moderate essential hypertension.

PubMed

Yonga, G O; Ogola, E N; Orinda, D A

1993-11-01

In a prospective single-blind comparative trial, sixty newly diagnosed mild to moderate hypertensives were randomly assigned to either propranolol or hydroflumethiazide monotherapy. Baseline fasting serum glucose lipid profiles, serum uric acid and potassium levels, were determined at the beginning of the trial. Repeat levels were determined at completion of twelve weeks of treatment. Propranolol treatment significantly reduced HDL-cholesterol (p < 0.02) and increased both VLDL and total serum triglycerides (p < 0.01). Hydroflumethiazide significantly increased total and LDL-chole-sterol, fasting serum glucose and uric acid levels (p < 0.01); potassium levels were significantly lowered (p < 0.01). Treatment with either propranolol or hydroflumethiazide is associated with significant metabolic side-effects which require regular monitoring and intervention as appropriate.

Vascular Glucose Sensor Symposium: Continuous Glucose Monitoring Systems (CGMS) for Hospitalized and Ambulatory Patients at Risk for Hyperglycemia, Hypoglycemia, and Glycemic Variability.

PubMed

Joseph, Jeffrey I; Torjman, Marc C; Strasma, Paul J

2015-07-01

Hyperglycemia, hypoglycemia, and glycemic variability have been associated with increased morbidity, mortality, length of stay, and cost in a variety of critical care and non-critical care patient populations in the hospital. The results from prospective randomized clinical trials designed to determine the risks and benefits of intensive insulin therapy and tight glycemic control have been confusing; and at times conflicting. The limitations of point-of-care blood glucose (BG) monitoring in the hospital highlight the great clinical need for an automated real-time continuous glucose monitoring system (CGMS) that can accurately measure the concentration of glucose every few minutes. Automation and standardization of the glucose measurement process have the potential to significantly improve BG control, clinical outcome, safety and cost. © 2015 Diabetes Technology Society.

Comparative performance assessment of point-of-care testing devices for measuring glucose and ketones at the patient bedside.

PubMed

Ceriotti, Ferruccio; Kaczmarek, Ewa; Guerra, Elena; Mastrantonio, Fabrizio; Lucarelli, Fausto; Valgimigli, Francesco; Mosca, Andrea

2015-03-01

Point-of-care (POC) testing devices for monitoring glucose and ketones can play a key role in the management of dysglycemia in hospitalized diabetes patients. The accuracy of glucose devices can be influenced by biochemical changes that commonly occur in critically ill hospital patients and by the medication prescribed. Little is known about the influence of these factors on ketone POC measurements. The aim of this study was to assess the analytical performance of POC hospital whole-blood glucose and ketone meters and the extent of glucose interference factors on the design and accuracy of ketone results. StatStrip glucose/ketone, Optium FreeStyle glucose/ketone, and Accu-Chek Performa glucose were also assessed and results compared to a central laboratory reference method. The analytical evaluation was performed according to Clinical and Laboratory Standards Institute (CLSI) protocols for precision, linearity, method comparison, and interference. The interferences assessed included acetoacetate, acetaminophen, ascorbic acid, galactose, maltose, uric acid, and sodium. The accuracies of both Optium ketone and glucose measurements were significantly influenced by varying levels of hematocrit and ascorbic acid. StatStrip ketone and glucose measurements were unaffected by the interferences tested with exception of ascorbic acid, which reduced the higher level ketone value. The accuracy of Accu-Chek glucose measurements was affected by hematocrit, by ascorbic acid, and significantly by galactose. The method correlation assessment indicated differences between the meters in compliance to ISO 15197 and CLSI 12-A3 performance criteria. Combined POC glucose/ketone methods are now available. The use of these devices in a hospital setting requires careful consideration with regard to the selection of instruments not sensitive to hematocrit variation and presence of interfering substances. © 2014 Diabetes Technology Society.

How to Design a Biosensor

PubMed Central

Ward, W. Kenneth

2007-01-01

Amperometric sensors for continuous glucose monitoring could prevent acute and chronic complications of diabetes, but research is needed to improve accuracy and stability. In designing sensors, interference from non-glucose analytes can be minimized by use of filtration membranes or electron transfer mediators that allow polarization at low potentials. If oxygen is required for the enzymatic reaction with glucose, then the outer permselective membrane must have substantial oxygen permeability. For this reason, during development of permselective membranes, permeability studies (such as performed by Tipnis and colleagues in this issue) can be used to measure transport of glucose and oxygen and optimize membrane structure. Tipnis and colleagues present a novel biosensor based with separate layers for glucose-oxygen permselectivity, enzymatic conversion, and avoidance of interference. They also address sensor stability, in part by comparing sensor function during ascending vs descending glucose levels. By measuring the difference, they were able to minimize this aspect of instability (hysterisis), which assisted them in selecting a promising permselective membrane based on iron and humic acid. PMID:19888407

How to design a biosensor.

PubMed

Ward, W Kenneth

2007-03-01

Amperometric sensors for continuous glucose monitoring could prevent acute and chronic complications of diabetes, but research is needed to improve accuracy and stability. In designing sensors, interference from non-glucose analytes can be minimized by use of filtration membranes or electron transfer mediators that allow polarization at low potentials. If oxygen is required for the enzymatic reaction with glucose, then the outer permselective membrane must have substantial oxygen permeability. For this reason, during development of permselective membranes, permeability studies (such as performed by Tipnis and colleagues in this issue) can be used to measure transport of glucose and oxygen and optimize membrane structure. Tipnis and colleagues present a novel biosensor based with separate layers for glucose-oxygen permselectivity, enzymatic conversion, and avoidance of interference. They also address sensor stability, in part by comparing sensor function during ascending vs descending glucose levels. By measuring the difference, they were able to minimize this aspect of instability (hysterisis), which assisted them in selecting a promising permselective membrane based on iron and humic acid.

How does CKD affect HbA1c?

PubMed

Bloomgarden, Zachary; Handelsman, Yehuda

2018-04-01

HOW DOES CHRONIC KIDNEY DISEASE AFFECT HBA1C?: A number of factors determine HbA1c other than the level of glucose exposure alone. In an subset analysis of the Atherosclerosis Risk in Communities study of 941 diabetic people with varying degrees of chronic kidney disease (CKD), as well as 724 who did not have CKD, and mean age in the eighth decade, Jung et al. ask whether HbA1c is reliable as an indicator of glycemia in people with kidney disease (CKD) to the same degree as in those not having kidney disease, and, if not, whether measures of glycated serum proteins may be more useful. The only available measure of glycemia for comparison was a single fasting glucose level, and the authors acknowledge that this gives an incomplete measure, particularly in people with relatively mild diabetes, whose mean HbA1c was 6.4%, with most having levels of 7.5% or lower. In patients of this sort, postprandial glucose levels may better explain variations in mean HbA1c. Recognizing that the dataset may be limited, Jung et al. nevertheless give an intriguingly negative answer to the first question, of the reliability of HbA1c with kidney disease. Using Deming regression analysis, Jung et al. showed that the correlation between HbA1c and fasting glucose weakens as renal function worsens, and, moreover, that this appears particularly to be the case in people with anemia (hemoglobin <130 and <120 g/L for men and women, respectively), confirming earlier observations. Among those diabetic people with neither anemia nor CKD, the correlation coefficient between HbA1c and fasting glucose was r = 0.70, compared with r = 0.35 among those with both anemia and very severe CKD (estimated glomerular filtration rate [eGFR] <30 or <45 mL/min per 1.73 m 2 with at least microalbuminuria, or eGFR <60 mL/min per 1.73 m 2 with macroalbuminuria). As far as the second question, of whether the alternative measures, namely fructosamine and glycated albumin, may be more useful with CKD, Jung et al. found that these parameters are equally flawed with CKD. Intriguingly, this suggests that anemia affects indirect measures of glycemic exposure not only by its association with more rapid erythrocyte turnover, but, more generally, also as a marker of a catabolic state with altered plasma protein turnover. How, then, should we assess a given diabetic person's degree of glycemic control in the presence of CKD (or of anemia, which, per Jung et al., was, even without CKD, also associated with a reduction in the correlation between HbA1c and fasting glucose)? Jung et al. suggest the use of continuous glucose monitoring to estimate average glucose. Although becoming recognized as an important tool, this technology is not as generally available as the simpler self-monitoring of blood glucose (SMBG). In an earlier analysis of potential complexities of HbA1c as a measure of glycemic exposure, we showed that self-monitored plasma glucose profiles suggest that approximately 10% of individuals with diabetes have HbA1c substantially above and another 10% have HbA1c substantially below those that may be anticipated based on mean glucose levels. In clinical practice, then, we should consider encouraging older people with diabetes and CKD to perform SMBG to more adequately interpret HbA1c results. © 2017 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

Glucose-Responsive Implantable Polymeric Microdevices for "Smart" Insulin Therapy of Diabetes

NASA Astrophysics Data System (ADS)

Chu, Michael Kok Loon

Diabetes mellitus is a chronic illness manifested by improper blood glucose management, affecting over 350 million worldwide. As a result, all type 1 patients and roughly 20% of type 2 patients require exogenous insulin therapy to survive. Typically, daily multiple injections are taken to maintain normal glucose levels in response glucose spikes from meals. However, patient compliance and dosing accuracy can fluctuate with variation in meals, exercise, glucose metabolism or stress, leading to poor clinical outcomes. A 'smart', closed-loop insulin delivery system providing on-demand release kinetics responding to circulating glucose levels would be a boon for diabetes patients, replacing constant self monitoring and insulin. This thesis focuses on the development of a novel, 'smart' insulin microdevice that can provide on-demand insulin release in response to blood glucose levels. In the early stage, the feasibility of integrating a composite membrane with pH-responsive nanoparticles embedded in ethylcellulose membrane to provide pH-responsive in vitro release was examined and confirmed using a model drug, vitamin B12. In the second microdevice, glucose oxidase for generating pH signals from glucose oxidation, catalase and manganese dioxide nanoparticles, as peroxide scavengers, were used in a bioinorganic, albumin-based membrane cross-linked with a polydimethylsiloxane (PDMS) grid-microdevice system. This prototype device demonstrated insulin release in response to glucose levels in vitro and regulating plasma glucose in type 1 diabetic rats when implanted intraperitoneally. Advancement allowing for subcutaneous implantation and improved biocompatibility was achieved with surface modification of PDMS microdevices grafted with activated 20 kDa polyethylene glycol (PEG) chains, dramatically reducing immune response and local inflammation. When implanted subcutaneously in diabetic rats, glucose-responsive insulin delivery microdevices showed short and long-term efficacy up to an 18 day period. Finally, to improve insulin stability within microdevice reservoirs, an in situ gelling zinc-insulin formulation was designed. High concentration insulin gel complexed with zinc provided physical and chemical stability against thermal denaturation over a 30 day period. Long-term stability of the zinc-insulin gel formulation shows potential for sustained release application, providing low-level, basal insulin release. These combined technologies present significant progress towards the goal of an 'artificial pancreas' to combat diabetes through 'smart' insulin therapy.

Measurement of tissue optical properties with optical coherence tomography: Implication for noninvasive blood glucose concentration monitoring

NASA Astrophysics Data System (ADS)

Larin, Kirill V.

Approximately 14 million people in the USA and more than 140 million people worldwide suffer from diabetes mellitus. The current glucose sensing technique involves a finger puncture several times a day to obtain a droplet of blood for analysis. There have been enormous efforts by many scientific groups and companies to quantify glucose concentration noninvasively using different optical techniques. However, these techniques face limitations associated with low sensitivity, accuracy, and insufficient specificity of glucose concentrations over a physiological range. Optical coherence tomography (OCT), a new technology, is being applied for noninvasive imaging in tissues with high resolution. OCT utilizes sensitive detection of photons coherently scattered from tissue. The high resolution of this technique allows for exceptionally accurate measurement of tissue scattering from a specific layer of skin compared with other optical techniques and, therefore, may provide noninvasive and continuous monitoring of blood glucose concentration with high accuracy. In this dissertation work I experimentally and theoretically investigate feasibility of noninvasive, real-time, sensitive, and specific monitoring of blood glucose concentration using an OCT-based biosensor. The studies were performed in scattering media with stable optical properties (aqueous suspensions of polystyrene microspheres and milk), animals (New Zealand white rabbits and Yucatan micropigs), and normal subjects (during oral glucose tolerance tests). The results of these studies demonstrated: (1) capability of the OCT technique to detect changes in scattering coefficient with the accuracy of about 1.5%; (2) a sharp and linear decrease of the OCT signal slope in the dermis with the increase of blood glucose concentration; (3) the change in the OCT signal slope measured during bolus glucose injection experiments (characterized by a sharp increase of blood glucose concentration) is higher than that measured in the glucose clamping experiments (characterized by slow, controlled increase of the blood glucose concentration); and (4) the accuracy of glucose concentration monitoring may substantially be improved if optimal dimensions of the probed skin area are used. The results suggest that high-resolution OCT technique has a potential for noninvasive, accurate, and continuous glucose monitoring with high sensitivity.

Comparison of lancing devices for self-monitoring of blood glucose regarding lancing pain.

PubMed

Kocher, Serge; Tshiananga, J K Tshiang; Koubek, Richard

2009-09-01

Self-monitoring of blood glucose empowers diabetes patients to effectively control their blood glucose (BG) levels. A potential barrier to frequent BG controls is lancing pain, intrinsically linked to pricking the finger several times a day. In this study, we compared different state-of-the-art lancing devices from leading manufacturers regarding lancing pain, and we intended to identify lancing devices that are less painful. First, 165 subjects compared 6 different BG monitoring systems-consisting of a lancing device and a BG meter-at home for 36 days and at least 3 BG tests per day. Second, the subjects directly compared 6 different lancing devices-independent from a BG meter-in a laboratory setting. The test results were collected in questionnaires, and lancing pain was rated on a numerical rating scale. One hundred fifty-seven subjects were included in the analysis. Accu-Chek BG monitoring systems were significantly (p < or = .006) preferred to competitor BG monitoring systems and were rated by >50% of the subjects as "less painful" than competitor BG monitoring systems. Accu-Chek lancing devices were significantly (p < .001) preferred to competitor lancing devices and were rated by >60% of the subjects as "less painful" than competitor lancing devices. We found significant differences in lancing pain between lancing devices. Diabetes patients clearly preferred lancing devices that cause less lancing pain. In order to improve patient compliance with respect to an adequate glycemic control, the medical staff should preferentially prescribe lancing devices that cause less lancing pain. 2009 Diabetes Technology Society.

Comparison of Lancing Devices for Self-Monitoring of Blood Glucose Regarding Lancing Pain

PubMed Central

Kocher, Serge; Tshiananga, J. K. Tshiang; Koubek, Richard

2009-01-01

Background Self-monitoring of blood glucose empowers diabetes patients to effectively control their blood glucose (BG) levels. A potential barrier to frequent BG controls is lancing pain, intrinsically linked to pricking the finger several times a day. In this study, we compared different state-of-the-art lancing devices from leading manufacturers regarding lancing pain, and we intended to identify lancing devices that are less painful. Methods First, 165 subjects compared 6 different BG monitoring systems—consisting of a lancing device and a BG meter—at home for 36 days and at least 3 BG tests per day. Second, the subjects directly compared 6 different lancing devices—independent from a BG meter—in a laboratory setting. The test results were collected in questionnaires, and lancing pain was rated on a numerical rating scale. Results One hundred fifty-seven subjects were included in the analysis. Accu-Chek BG monitoring systems were significantly (p ≤ .006) preferred to competitor BG monitoring systems and were rated by >50% of the subjects as “less painful” than competitor BG monitoring systems. Accu-Chek lancing devices were significantly (p < .001) preferred to competitor lancing devices and were rated by >60% of the subjects as “less painful” than competitor lancing devices. Conclusions We found significant differences in lancing pain between lancing devices. Diabetes patients clearly preferred lancing devices that cause less lancing pain. In order to improve patient compliance with respect to an adequate glycemic control, the medical staff should preferentially prescribe lancing devices that cause less lancing pain. PMID:20144427

Cook and Chill: Effect of Temperature on the Performance of Nonequilibrated Blood Glucose Meters.

PubMed

Deakin, Sherine; Steele, Dominic; Clarke, Sarah; Gribben, Cathryn; Bexley, Anne-Marie; Laan, Remmert; Kerr, David

2015-08-20

Exposure to extreme temperature can affect the performance of blood glucose monitoring systems. The aim was to determine the non-equilibrated performance of these systems at extreme high and low temperatures that can occur in daily life. The performances of 5 test systems, (1) Abbott FreeStyle Freedom Lite, (2) Roche AccuChek Aviva, (3) Bayer Contour, (4) LifeScan OneTouch Verio, and (5) Sanofi BG Star, were compared after "cooking" (50°C for 1 hour) or "chilling" (-5°C for 1 hour) with room temperature controls (23°C) using whole blood with glucose concentrations of 50, 100, and 200 mg/dl. The equilibration period (time from the end of incubation to when the test system is operational) was between 1 and 8 minutes, and each test system took between 15 and 30 minutes after incubation to obtain stable measurements at room temperature. Incubating the strips at -5°C or 50°C had little effect on the glucose measurement, whereas incubating the meters introduced bias in performance between 0 and 15 minutes but not subsequently, compared to room temperature controls and at all 3 glucose levels. Compensating technologies embedded within blood glucose monitoring systems studied here perform well at extreme temperatures. People with diabetes need to be alerted to this feature to avoid perceptions of malperformance of their devices and the possible inability to get blood glucose readings on short notice (eg, during time of suspected rapid change or before an unplanned meal). © 2015 Diabetes Technology Society.

Accuracy of continuous glucose monitoring during exercise in type 1 diabetes pregnancy.

PubMed

Kumareswaran, Kavita; Elleri, Daniela; Allen, Janet M; Caldwell, Karen; Nodale, Marianna; Wilinska, Malgorzata E; Amiel, Stephanie A; Hovorka, Roman; Murphy, Helen R

2013-03-01

Performance of continuous glucose monitors (CGMs) may be lower when glucose levels are changing rapidly, such as occurs during physical activity. Our aim was to evaluate accuracy of a current-generation CGM during moderate-intensity exercise in type 1 diabetes (T1D) pregnancy. As part of a study of 24-h closed-loop insulin delivery in 12 women with T1D (disease duration, 17.6 years; glycosylated hemoglobin, 6.4%) during pregnancy (gestation, 21 weeks), we evaluated the Freestyle Navigator(®) sensor (Abbott Diabetes Care, Alameda, CA) during afternoon (15:00-18:00 h) and morning (09:30-12:30 h) exercise (55 min of brisk walking on a treadmill followed by a 2-h recovery), compared with sedentary conditions (18:00-09:00 h). Plasma (reference) glucose, measured at regular 15-30-min intervals with the YSI Ltd. (Fleet, United Kingdom) model YSI 2300 analyzer, was used to assess CGM performance. Sensor accuracy, as indicated by the larger relative absolute difference (RAD) between paired sensor and reference glucose values, was lower during exercise compared with rest (median RAD, 11.8% vs. 18.4%; P<0.001). These differences remained significant when correcting for plasma glucose relative rate of change (P<0.001). Analysis by glucose range showed lower accuracy during hypoglycemia for both sedentary (median RAD, 24.4%) and exercise (median RAD, 32.1%) conditions. Using Clarke error grid analysis, 96% of CGM values were clinically safe under resting conditions compared with only 87% during exercise. Compared with sedentary conditions, accuracy of the Freestyle Navigator CGM was lower during moderate-intensity exercise in pregnant women with T1D. This difference was particularly marked in hypoglycemia and could not be solely explained by the glucose rate of change associated with physical activity.

Use of continuous glucose monitoring as an outcome measure in clinical trials.

PubMed

Beck, Roy W; Calhoun, Peter; Kollman, Craig

2012-10-01

Although developed to be a management tool for individuals with diabetes, continuous glucose monitoring (CGM) also has potential value for the assessment of outcomes in clinical studies. We evaluated using CGM as such an outcome measure. Data were analyzed from six previously completed inpatient studies in which both CGM (Freestyle Navigator™ [Abbott Diabetes Care, Alameda, CA] or Guardian(®) [Medtronic, Northridge, CA]) and reference glucose measurements were available. The analyses included 97 days of data from 93 participants with type 1 diabetes (age range, 5-57 years; mean, 18 ± 12 years). Mean glucose levels per day were similar for the CGM and reference measurements (median, 148 mg/dL vs. 143 mg/dL, respectively; P = 0.92), and the correlation of the two was high (r = 0.89). Similarly, most glycemia metrics showed no significant differences comparing CGM and reference values, except that the nadir glucose tended to be slightly lower and peak glucose slightly higher with reference measurements than CGM measurements (respective median, 59 mg/dL vs. 66 mg/dL [P = 0.05] and 262 mg/dL vs. 257 mg/dL [P = 0.003]) and glucose variability as measured with the coefficient of variation was slightly lower with CGM than reference measurements (respective median, 31% vs. 35%; P<0.001). A reasonably high degree of concordance exists when comparing outcomes based on CGM measurements with outcomes based on reference blood glucose measurements. CGM inaccuracy and underestimation of the extremes of hyperglycemia and hypoglycemia can be accounted for in a clinical trial's study design. Thus, in appropriate settings, CGM can be a very meaningful and feasible outcome measure for clinical trials.

A screen-printed microband glucose biosensor system for real-time monitoring of toxicity in cell culture.

PubMed

Pemberton, R M; Xu, J; Pittson, R; Drago, G A; Griffiths, J; Jackson, S K; Hart, J P

2011-01-15

Microband biosensors, screen-printed from a water-based carbon ink containing cobalt phthalocyanine redox mediator and glucose oxidase (GOD) enzyme, were used to monitor glucose levels continuously in buffer and culture medium. Five biosensors were operated amperometrically (E(app) of +0.4V), in a 12-well tissue culture plate system at 37°C, using a multipotentiostat. After 24 h, a linear calibration plot was obtained from steady-state current responses for glucose concentrations up to 10 mM (dynamic range 30 mM). Within the linear region, a correlation coefficient (R(2)) of 0.981 was obtained between biosensor and spectrophotometric assays. Over 24 h, an estimated 0.15% (89 nmol) of the starting glucose concentration (24 mM) was consumed by the microbiosensor. The sensitivity of the biosensor response in full culture medium was stable between pHs 7.3 and 8.4. Amperometric responses for HepG2 monolayer cultures decreased with time in inverse proportionality to cell number (for 0 to 10(6) cell/ml), as glucose was being metabolised. HepG2 3D cultures (spheroids) were also shown to metabolise glucose, at a rate which was independent of spheroid age (between 6 and 15 days). Spheroids were used to assay the effect of a typical hepatotoxin, paracetamol. At 1 mM paracetamol, glucose uptake was inhibited by 95% after 6 h in culture; at 500 μM, around 15% inhibition was observed after 16 h. This microband biosensor culture system could form the basis for an in vitro toxicity testing system. Copyright © 2010 Elsevier B.V. All rights reserved.

Use of Continuous Glucose Monitoring as an Outcome Measure in Clinical Trials

PubMed Central

Calhoun, Peter; Kollman, Craig

2012-01-01

Abstract Objective Although developed to be a management tool for individuals with diabetes, continuous glucose monitoring (CGM) also has potential value for the assessment of outcomes in clinical studies. We evaluated using CGM as such an outcome measure. Research Design and Methods Data were analyzed from six previously completed inpatient studies in which both CGM (Freestyle Navigator™ [Abbott Diabetes Care, Alameda, CA] or Guardian® [Medtronic, Northridge, CA]) and reference glucose measurements were available. The analyses included 97 days of data from 93 participants with type 1 diabetes (age range, 5–57 years; mean, 18±12 years). Results Mean glucose levels per day were similar for the CGM and reference measurements (median, 148 mg/dL vs. 143 mg/dL, respectively; P=0.92), and the correlation of the two was high (r=0.89). Similarly, most glycemia metrics showed no significant differences comparing CGM and reference values, except that the nadir glucose tended to be slightly lower and peak glucose slightly higher with reference measurements than CGM measurements (respective median, 59 mg/dL vs. 66 mg/dL [P=0.05] and 262 mg/dL vs. 257 mg/dL [P=0.003]) and glucose variability as measured with the coefficient of variation was slightly lower with CGM than reference measurements (respective median, 31% vs. 35%; P<0.001). Conclusions A reasonably high degree of concordance exists when comparing outcomes based on CGM measurements with outcomes based on reference blood glucose measurements. CGM inaccuracy and underestimation of the extremes of hyperglycemia and hypoglycemia can be accounted for in a clinical trial's study design. Thus, in appropriate settings, CGM can be a very meaningful and feasible outcome measure for clinical trials. PMID:23013201

Reliable long-term continuous blood glucose monitoring for patients in critical care using microdialysis and infrared spectrometry

NASA Astrophysics Data System (ADS)

Heise, H. Michael; Damm, Uwe; Kondepati, Venkata R.

2006-02-01

For clinical research, in-vivo blood glucose monitoring is an ongoing important topic to improve glycemic control in patients with non-adequate blood glucose regulation. Critically ill patients received much interest, since the intensive insulin therapy treatment, as established for diabetics, reduces mortality significantly. Despite the existence of commercially available, mainly amperometric biosensors, continued interest is in infrared spectroscopic techniques for reagent-free glucose monitoring. For stable long-term operation, avoiding also sensor recalibration, a bed-side device coupled to a micro-dialysis probe was developed for quasi-continuous glucose monitoring. Multivariate calibration is required for glucose concentration prediction due to the complex composition of dialysates from interstitial body fluid. Measurements were carried out with different test persons, each experiment lasting for more than 8 hours. Owing to low dialysis recovery rates, glucose concentrations in the dialysates were between 0.83 and 4.44 mM. Standard errors of prediction (SEP) obtained with Partial Least Squares (PLS) calibration and different cross-validation strategies were mainly between 0.13 and 0.18 mM based on either full interval data or specially selected spectral variables.

Multilevel Analysis of Socioeconomic Determinants on Diabetes Prevalence, Awareness, Treatment and Self-Management in Ethnic Minorities of Yunnan Province, China

PubMed Central

Su, Rong; Cai, Le; Cui, Wenlong; He, Jianhui; You, Dingyun; Golden, Allison

2016-01-01

Objectives: The objective of this manuscript is to investigate socioeconomic differences in prevalence, awareness, treatment and self-management of diabetes among ethnic minority groups in Yunnan Province, China. Methods: We conducted a cross-sectional survey in a sample of 5532 Na Xi, Li Su, Dai and Jing Po ethnic minorities. Multilevel modeling was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for diabetes prevalence, as well as the other outcomes. Results: Higher individual educational level was associated with a higher rate of awareness, treatment, adherence to medicines and monitoring of blood glucose (OR = 1.87, 4.89, 4.83, 6.45; 95% CI: 1.26–2.77, 1.87–12.7, 1.95–11.9, 2.23–18.6, respectively). Diabetic respondents with better household assets tended to receive more treatment (OR = 2.81, 95% CI: 1.11–7.12) and to monitor their blood glucose (OR = 3.29, 95% CI: 1.48–7.30). Diabetic patients with better access to medical services were more likely to treat (OR = 7.09, 95% CI: 2.46–20.4) and adhere to medication (OR = 4.14, 95% CI: 1.46–11.7). Income at the contextual level was significantly correlated with diabetes prevalence, treatment and blood glucose monitoring (OR = 1.84, 3.04, 4.34; 95% CI: 1.20–2.83, 1.20–7.73, 1.45–13.0, respectively). Conclusions: Future diabetes prevention and intervention programs should take both individual and township-level socioeconomic factors into account in the study regions. PMID:27463725

Evaluation of a new portable glucose meter designed for the use in cats.

PubMed

Zini, E; Moretti, S; Tschuor, F; Reusch, C E

2009-09-01

Portable blood glucose meters (PBGMs) are useful in the management of diabetes mellitus in cats. In the present study we compared the performance of two PBGMs: the AlphaTRAK (Abbott Animal Health, Maidenhead, England) specifically developed for dogs and cats, and the Ascensia ELITE (Bayer HealthCare, Zurich, Switzerland) developed for humans. Quality parameters, including precision and accuracy, were better for the AlphaTRAK meter compared to Ascensia ELITE. While the AlphaTRAK meter results did not differ from the reference method, results from the Ascensia ELITE were significantly (P<0.001) lower. The superior performance of the AlphaTRAK meter supports its use to monitor blood glucose levels in cats.

NANOPARTICLE DELIVERED BIOSENSOR FOR REACTIVE OXYGEN SPECIES IN DIABETES

PubMed Central

Prow, Tarl W.; Bhutto, Imran; Grebe, Rhonda; Uno, Koichi; Merges, Carol; Mcleod, D. Scott; Lutty, Gerard A.

2008-01-01

The cell’s own antioxidant response element (ARE) can be used to evaluate the complications of diabetes mellitus. The hypothesis that a synthetic ARE could be used as a genetic switch, or biosensor, to turn on and off therapeutic genes is tested herein. Mitochondrial oxidative stress (MOS) has been hypothesized as one of the earliest insults in diabetes. Fluorescent probes used to monitor MOS revealed that the addition of glucose at physiological levels to cultures of endothelial cells was able to induce MOS above normal levels and in a dose dependant manner. Additional data showed that increased glucose levels activated the ARE-GFP in a dose dependant manner. These data support the hypothesis that the induction of MOS is more sensitive to hyperglycemia than the induction of the ARE. Delivery of an ARE-GFP construct with nanoparticles to the eye was successful using sub-retinal injection. This ARE-GFP/nanoparticle construct was functional and reported the activation of the ARE in diabetic rat retinal pigment epithelium (RPE). These data support the use of nanoparticle delivered biosensors for monitoring the oxidative status of tissues in vivo. PMID:18252237

Nanoparticle-delivered biosensor for reactive oxygen species in diabetes.

PubMed

Prow, Tarl W; Bhutto, Imran; Grebe, Rhonda; Uno, Koichi; Merges, Carol; McLeod, D Scott; Lutty, Gerard A

2008-02-01

The cell's own antioxidant response element (ARE) can be used to evaluate the complications of diabetes mellitus. The hypothesis that a synthetic ARE could be used as a genetic switch, or biosensor, to turn on and off therapeutic genes is tested herein. Mitochondrial oxidative stress (MOS) has been hypothesized as one of the earliest insults in diabetes. Fluorescent probes used to monitor MOS revealed that the addition of glucose at physiological levels to cultures of endothelial cells was able to induce MOS above normal levels and in a dose-dependant manner. Additional data showed that increased glucose levels activated the ARE-GFP in a dose-dependant manner. These data support the hypothesis that the induction of MOS is more sensitive to hyperglycemia than the induction of the ARE. Delivery of an ARE-GFP construct with nanoparticles to the eye was successful using sub-retinal injection. This ARE-GFP/nanoparticle construct was functional and reported the activation of the ARE in diabetic rat retinal pigment epithelium (RPE). These data support the use of nanoparticle-delivered biosensors for monitoring the oxidative status of tissues in vivo.

Hypoglycaemia incidence and recovery during home use of hybrid closed-loop insulin delivery in adults with type 1 diabetes.

PubMed

Ruan, Yue; Bally, Lia; Thabit, Hood; Leelarathna, Lalantha; Hartnell, Sara; Tauschmann, Martin; Wilinska, Malgorzata E; Evans, Mark L; Mader, Julia K; Kojzar, Harald; Dellweg, Sibylle; Benesch, Carsten; Arnolds, Sabine; Pieber, Thomas R; Hovorka, Roman

2018-03-25

Glucose excursion was assessed prior to and post hypoglycaemia to increase understanding of hypoglycaemia incidence and recovery during hybrid closed-loop insulin delivery. We retrospectively analysed data from 60 adults with type 1 diabetes who received, in a crossover randomized design, day-and-night hybrid closed-loop insulin delivery and insulin pump therapy, the latter with or without real-time continuous glucose monitoring. Over 4-week study periods, we identified hypoglycaemic episodes, defined as sensor glucose <3.0 mmol/L, and analysed sensor glucose relative to the onset of hypoglycaemia. We identified 377 hypoglycaemic episodes during hybrid closed-loop intervention vs 662 during control intervention (P < .001), with a predominant reduction of nocturnal hypoglycaemia. The slope of sensor glucose prior to hypoglycaemia was steeper during closed-loop intervention than during control intervention (P < .01), while insulin delivery was reduced (P < .01). During both day and night, participants recovered from hypoglycaemia faster when treated by closed-loop intervention. At 120 minutes post hypoglycaemia, sensor glucose levels were higher during closed-loop intervention compared to the control period (P < .05). In conclusion, closed-loop intervention reduces the risk of hypoglycaemia, particularly overnight, with swift recovery from hypoglycaemia leading to higher 2-hour post-hypoglycaemia glucose levels. © 2018 John Wiley & Sons Ltd.

Ambulatory glucose profile analysis of the juvenile diabetes research foundation continuous glucose monitoring dataset-Applications to the pediatric diabetes population.

PubMed

Forlenza, Gregory P; Pyle, Laura L; Maahs, David M; Dunn, Timothy C

2017-11-01

Increased continuous glucose monitor (CGM) use presents both the benefit and burden of increased data for clinicians to rapidly analyze. The ambulatory glucose profile (AGP) is an evolving a universal software report for CGM data analysis. We utilized the Juvenile Diabetes Research Foundation-CGM dataset to evaluate the AGP across a broad spectrum of patients to show how AGP can be used clinically to assist with CGM-related decision making. We hypothesized that AGP metrics would be different across age and HbA1c strata. AGPs were generated from the JDRF-CGM trial dataset for all periods during which there were ≥10 days of CGM coverage in the 2 weeks adjacent to an HbA1c measurement yielding 1101 AGPs for 393 unique subjects. AGPs were stratified by age group (8-14, 15-24, and ≥25 years) and HbA1c (within or above target for age) and compared for between group differences in AGP metrics via two-factor ANOVA. Glycemic differences between time periods were analyzed via segmented regression analysis. Glucose exposure (average and estimated A1c) and variability (standard deviation and interquartile range) were different between the low and high HbA1c levels. Within a given HbA1c level all age groups were significantly different from each other with older patients having lower averages with less variability than younger patients. AGP analysis of the JDRF-CGM data highlights significant differences in glycemic profiles between pediatric and adult age groups and between well and less well-controlled patient populations. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lancing: Quo Vadis?

PubMed Central

Heinemann, Lutz; Boecker, Dirk

2011-01-01

Today, lancing fingertips or alternative sites for obtaining a blood sample for self-monitoring of blood glucose (SMBG) is a standard procedure for most patients with diabetes. The need for frequent lancing and associated discomfort and pain can be seen as a key hurdle for patients to comply with SMBG regimens. This article provides an overview of the status quo and future of lancing, focusing on key areas for future developments driven by customer and market needs. We also review technical issues and provide a background for possible improvements. The act of puncturing the skin with a lancet to obtain a blood sample seems to remain the standard procedure for the foreseeable future, because alternate ways of providing a blood sample have not demonstrated overall superiority (e.g., with laser technology). Other methods, which avoid lancing entirely, have also not gained broad market acceptance (e.g., minimally invasive continuous glucose monitoring) or not shown technical viability (e.g., noninvasive glucose monitoring). In relation to blood glucose (BG) meters and test strips, lancing has been a “stepchild” with regards to commercial attention and development efforts. Nevertheless, significant technological improvements have been made in this field to address key customer needs, including better performance (regarding pain, wound healing, and long-term sensitivity), reduced cost, and higher integration with other components of BG monitoring (e.g., integration of the lancing device with the glucose monitor). From a technical perspective, it is apparent that highly comfortable lancing can be accomplished; however, this still requires fairly advanced and complex devices. New developments are necessary to achieve this level of sophistication and performance with less intricate and costly system designs. Manufacturers' motivation to pursue these developments is compromised by the fact that they might not recoup their development cost on commercial advanced lancing systems through direct profits, but only through its positive influence on adherence and increased more profitable sensor utilization. We believe that two main driving forces will continue to push the evolution of lancing and sampling technology: (1) the need for maximum lancing comfort and (2) the advent of fully integrated systems, realizing a device in which all steps for SMBG are incorporated, thus providing a “one-step” experience. Rendering lancing a “nonissue” will eliminate a key barrier to adherence with appropriate SMBG regimens. Providing sophisticated lancing devices that allow the highest level of comfort and/or seamless blood sampling is key to improving user acceptance. This may have a greater impact on metabolic control than many of the new and expensive antidiabetic drugs. PMID:21880240

A Noninvasive In Vivo Glucose Sensor Based on Mid-Infrared Quantum Cascade Laser Spectroscopy

NASA Astrophysics Data System (ADS)

Werth, Alexandra; Liakat, Sabbir; Xu, Laura; Gmachl, Claire

Diabetes affects over 387 million people worldwide; a number which grows every year. The most common method of measuring blood glucose concentration involves a finger prick which for some can be a harrowing process. Therefore, a portable, accurate, noninvasive glucose sensor can significantly improve the quality of life for many of these diabetics who draw blood multiple times a day to monitor their glucose levels. We have implemented a noninvasive, mobile glucose sensor using a mid-infrared (MIR) quantum cascade laser (QCL), integrating sphere, and thermal electrically (TE) cooled detector. The QCL is scanned from 8 - 10 microns wavelength over which are distinct absorption features of glucose molecules with little competition of absorption from other molecules found in the blood and interstitial fluid. The obtained absorption spectra are analyzed using a neural network algorithm which relates the small changes in absorption to the changing glucose concentration. The integrating sphere has increased the signal-to-noise ratio from a previous design, allowing us to use the TE-cooled detector which increases mobility without loss of accuracy.

Blood glucose measurement in patients with suspected diabetic ketoacidosis: a comparison of Abbott MediSense PCx point-of-care meter values to reference laboratory values.

PubMed

Blank, Fidela S J; Miller, Moses; Nichols, James; Smithline, Howard; Crabb, Gillian; Pekow, Penelope

2009-04-01

The purpose of this study is to compare blood glucose levels measured by a point of care (POC) device to laboratory measurement using the same sample venous blood from patients with suspected diabetic ketoacidosis (DKA). A descriptive correlational design was used for this IRB-approved quality assurance project. The study site was the 50-bed BMC emergency department (ED) which has an annual census of over 100,000 patient visits. The convenience sample consisted of 54 blood samples from suspected DKA patients with orders for hourly blood draws for glucose measurement. Spearman correlations of the glucose POC values, reference lab values, and differences between the two, were evaluated. A chi-square test was used to evaluate the association between the acidosis status and FDA acceptability of POC values. Patient age range was 10-86 years; 63% were females; 46% had a final diagnosis of DKA. POC values underestimated glucose levels 93% of the time. There was a high correlation between the lab value and the magnitude of the difference, (lab minus POC value) indicating that the higher the true glucose value, the greater the difference between the lab and the POC value. A chi-square test showed no overall association between acidosis and FDA-acceptability. The POC values underestimated lab reported glucose levels in 50 of 54 cases even with the use of same venous sample sent to the lab, which make it highly unreliable for use in monitoring suspected DKA patients.

Cognitive and physiological effects of an "energy drink": an evaluation of the whole drink and of glucose, caffeine and herbal flavouring fractions.

PubMed

Scholey, Andrew B; Kennedy, David O

2004-11-01

Both glucose and caffeine can improve aspects of cognitive performance and, in the case of caffeine, mood. There are few studies investigating the effects of the two substances in combination. We assessed the mood, cognitive and physiological effects of a soft drink containing caffeine and glucose as well as flavouring levels of herbal extracts. The effects of different drink fractions were also evaluated. Using a randomised, double-blind, balanced, five-way crossover design, 20 participants who were overnight fasted and caffeine-deprived received 250 ml drinks containing 37.5 g glucose; 75 mg caffeine; ginseng and ginkgo biloba at flavouring levels; a whole drink (containing all these substances) or a placebo (vehicle). Participants were assessed in each drink condition, separated by a 7-day wash-out period. Cognitive, psychomotor and mood assessment took place immediately prior to the drink then 30 min thereafter. The primary outcome measures included five aspects of cognitive performance from the Cognitive Drug Research assessment battery. Mood, heart rate and blood glucose levels were also monitored. Compared with placebo, the whole drink resulted in significantly improved performance on "secondary memory" and "speed of attention" factors. There were no other cognitive or mood effects. This pattern of results would not be predicted from the effects of glucose and caffeine in isolation, either as seen here or from the literature addressing the effects of the substances in isolation. These data suggest that there is some degree of synergy between the cognition-modulating effects of glucose and caffeine which merits further investigation.

Optical microsensor for continuous glucose measurements in interstitial fluid

NASA Astrophysics Data System (ADS)

Olesberg, Jonathon T.; Cao, Chuanshun; Yager, Jeffrey R.; Prineas, John P.; Coretsopoulos, Chris; Arnold, Mark A.; Olafsen, Linda J.; Santilli, Michael

2006-02-01

Tight control of blood glucose levels has been shown to dramatically reduce the long-term complications of diabetes. Current invasive technology for monitoring glucose levels is effective but underutilized by people with diabetes because of the pain of repeated finger-sticks, the inconvenience of handling samples of blood, and the cost of reagent strips. A continuous glucose sensor coupled with an insulin delivery system could provide closed-loop glucose control without the need for discrete sampling or user intervention. We describe an optical glucose microsensor based on absorption spectroscopy in interstitial fluid that can potentially be implanted to provide continuous glucose readings. Light from a GaInAsSb LED in the 2.2-2.4 μm wavelength range is passed through a sample of interstitial fluid and a linear variable filter before being detected by an uncooled, 32-element GaInAsSb detector array. Spectral resolution is provided by the linear variable filter, which has a 10 nm band pass and a center wavelength that varies from 2.18-2.38 μm (4600-4200 cm -1) over the length of the detector array. The sensor assembly is a monolithic design requiring no coupling optics. In the present system, the LED running with 100 mA of drive current delivers 20 nW of power to each of the detector pixels, which have a noise-equivalent-power of 3 pW/Hz 1/2. This is sufficient to provide a signal-to-noise ratio of 4500 Hz 1/2 under detector-noise limited conditions. This signal-to-noise ratio corresponds to a spectral noise level less than 10 μAU for a five minute integration, which should be sufficient for sub-millimolar glucose detection.

Accuracy Evaluation of a CE-Marked Glucometer System for Self-Monitoring of Blood Glucose With Three Reagent Lots Following ISO 15197:2013.

PubMed

Hehmke, Bernd; Berg, Sabine; Salzsieder, Eckhard

2017-05-01

Continuous standardized verification of the accuracy of blood glucose meter systems for self-monitoring after their introduction into the market is an important clinically tool to assure reliable performance of subsequently released lots of strips. Moreover, such published verification studies permit comparison of different blood glucose monitoring systems and, thus, are increasingly involved in the process of evidence-based purchase decision making.

Resource guide 2004. Blood glucose. Monitors and data management systems.

PubMed

2004-01-01

Before you buy a blood glucose monitor (also known as a blood glucose meter), check with your doctor and diabetes educator. Make sure the one you choose is well suited to your particular needs. You might want to have one at home and one for use at school or the office.

Reliable glucose monitoring by ex-vivo blood microdialysis and infrared spectrometry for patients in critical care

NASA Astrophysics Data System (ADS)

Vahlsing, Thorsten; Delbeck, Sven; Budde, Janpeter; Ihrig, Dieter; Leonhardt, Steffen; Heise, H. Michael

2017-02-01

Blood glucose monitoring has been realised by biosensors in combination with micro-dialysis, using either subcutaneously or intravascularly implanted catheters. Another alternative is ex-vivo micro-dialysis of continuously sampled heparinized whole blood available from the patient even under critical care conditions. However, most devices suffer from inaccuracies due to variable recovery rates. Infrared spectrometry has been suggested for analyte quantification, since besides glucose other clinically relevant analytes can be simultaneously determined that are, e.g., important for intensive care patients. Perfusates with acetate and mannitol have been investigated as recovery markers (internal standards). In contrast to the previously used acetate, an almost linear dependency between mannitol loss and glucose recovery was observed for micro-dialysis of glucose spiked aqueous albumin solutions or porcine heparinized whole blood when testing flat membranes within a custom-made micro-dialysator. By this, a straightforward compensation of any dialysis recovery rate variation during patient monitoring is possible. The combination of microdialysis with infrared spectrometry provides a calibration-free assay for accurate continuous glucose monitoring, as reference spectra of dialysate components can be a-priori allocated.

CMOS image sensors as an efficient platform for glucose monitoring.

PubMed

Devadhasan, Jasmine Pramila; Kim, Sanghyo; Choi, Cheol Soo

2013-10-07

Complementary metal oxide semiconductor (CMOS) image sensors have been used previously in the analysis of biological samples. In the present study, a CMOS image sensor was used to monitor the concentration of oxidized mouse plasma glucose (86-322 mg dL(-1)) based on photon count variation. Measurement of the concentration of oxidized glucose was dependent on changes in color intensity; color intensity increased with increasing glucose concentration. The high color density of glucose highly prevented photons from passing through the polydimethylsiloxane (PDMS) chip, which suggests that the photon count was altered by color intensity. Photons were detected by a photodiode in the CMOS image sensor and converted to digital numbers by an analog to digital converter (ADC). Additionally, UV-spectral analysis and time-dependent photon analysis proved the efficiency of the detection system. This simple, effective, and consistent method for glucose measurement shows that CMOS image sensors are efficient devices for monitoring glucose in point-of-care applications.

'Knowing where I am': self-monitoring of blood glucose in diabetes.

PubMed

Meetoo, Danny; Wong, Louise; Fatani, Tughreed

2018-05-24

Although the prevalence of all types of chronic conditions is increasing, diabetes is one of the few long-term metabolic disorders that individuals can successfully manage, monitor and control on a day-to-day basis. Self-monitoring of blood glucose (SMBG) is considered an essential component of diabetes self-care management. When used appropriately, SMBG can help to identify factors associated with hyper- and hypoglycaemia, facilitate learning, and empower people with diabetes to make changes to improve their glycaemic control. SMBG can be a useful tool for healthcare providers, who can teach individuals to monitor glucose at specific times to assess the effectiveness of medications and guide medication management. However, there is an ongoing debate regarding whether, as is the case with type 1 diabetes, all people with type 2 diabetes should also be given the opportunity to learn about the value of, and skills required to, monitor blood glucose as appropriate to their specific needs.

Trends in Nanomaterial-Based Non-Invasive Diabetes Sensing Technologies

PubMed Central

Makaram, Prashanth; Owens, Dawn; Aceros, Juan

2014-01-01

Blood glucose monitoring is considered the gold standard for diabetes diagnostics and self-monitoring. However, the underlying process is invasive and highly uncomfortable for patients. Furthermore, the process must be completed several times a day to successfully manage the disease, which greatly contributes to the massive need for non-invasive monitoring options. Human serums, such as saliva, sweat, breath, urine and tears, contain traces of glucose and are easily accessible. Therefore, they allow minimal to non-invasive glucose monitoring, making them attractive alternatives to blood measurements. Numerous developments regarding noninvasive glucose detection techniques have taken place over the years, but recently, they have gained recognition as viable alternatives, due to the advent of nanotechnology-based sensors. Such sensors are optimal for testing the amount of glucose in serums other than blood thanks to their enhanced sensitivity and selectivity ranges, in addition to their size and compatibility with electronic circuitry. These nanotechnology approaches are rapidly evolving, and new techniques are constantly emerging. Hence, this manuscript aims to review current and future nanomaterial-based technologies utilizing saliva, sweat, breath and tears as a diagnostic medium for diabetes monitoring. PMID:26852676

Trends in Nanomaterial-Based Non-Invasive Diabetes Sensing Technologies.

PubMed

Makaram, Prashanth; Owens, Dawn; Aceros, Juan

2014-04-21

Blood glucose monitoring is considered the gold standard for diabetes diagnostics and self-monitoring. However, the underlying process is invasive and highly uncomfortable for patients. Furthermore, the process must be completed several times a day to successfully manage the disease, which greatly contributes to the massive need for non-invasive monitoring options. Human serums, such as saliva, sweat, breath, urine and tears, contain traces of glucose and are easily accessible. Therefore, they allow minimal to non-invasive glucose monitoring, making them attractive alternatives to blood measurements. Numerous developments regarding noninvasive glucose detection techniques have taken place over the years, but recently, they have gained recognition as viable alternatives, due to the advent of nanotechnology-based sensors. Such sensors are optimal for testing the amount of glucose in serums other than blood thanks to their enhanced sensitivity and selectivity ranges, in addition to their size and compatibility with electronic circuitry. These nanotechnology approaches are rapidly evolving, and new techniques are constantly emerging. Hence, this manuscript aims to review current and future nanomaterial-based technologies utilizing saliva, sweat, breath and tears as a diagnostic medium for diabetes monitoring.

Color record in self-monitoring of blood glucose improves glycemic control by better self-management.

PubMed

Nishimura, Akiko; Harashima, Shin-ichi; Honda, Ikumi; Shimizu, Yoshiyuki; Harada, Norio; Nagashima, Kazuaki; Hamasaki, Akihiro; Hosoda, Kiminori; Inagaki, Nobuya

2014-07-01

Color affects emotions, feelings, and behaviors. We hypothesized that color used in self-monitoring of blood glucose (SMBG) is helpful for patients to recognize and act on their glucose levels to improve glycemic control. Here, two color-indication methods, color record (CR) and color display (CD), were independently compared for their effects on glycemic control in less frequently insulin-treated type 2 diabetes. One hundred twenty outpatients were randomly allocated to four groups with 2×2 factorial design: CR or non-CR and CD or non-CD. Blood glucose levels were recorded in red or blue pencil in the CR arm, and a red or blue indicator light on the SMBG meter was lit in the CD arm, under hyperglycemia or hypoglycemia, respectively. The primary end point was difference in glycated hemoglobin (HbA1c) reduction in 24 weeks. Secondary end points were self-management performance change and psychological state change. HbA1c levels at 24 weeks were significantly decreased in the CR arm by -0.28% but were increased by 0.03% in the non-CR arm (P=0.044). In addition, diet and exercise scores were significantly improved in the CR arm compared with the non-CR arm. The exercise score showed significant improvement in the CD arm compared with the non-CD arm but without a significant difference in HbA1c reduction. Changes in psychological states were not altered between the arms. CR has a favorable effect on self-management performance without any influence on psychological stress, resulting in improved glycemic control in type 2 diabetes patients using less frequent insulin injection. Thus, active but not passive usage of color-indication methods by patients is important in successful SMBG.

Complexity of Continuous Glucose Monitoring Data in Critically Ill Patients: Continuous Glucose Monitoring Devices, Sensor Locations, and Detrended Fluctuation Analysis Methods

PubMed Central

Signal, Matthew; Thomas, Felicity; Shaw, Geoffrey M.; Chase, J. Geoffrey

2013-01-01

Background Critically ill patients often experience high levels of insulin resistance and stress-induced hyperglycemia, which may negatively impact outcomes. However, evidence surrounding the causes of negative outcomes remains inconclusive. Continuous glucose monitoring (CGM) devices allow researchers to investigate glucose complexity, using detrended fluctuation analysis (DFA), to determine whether it is associated with negative outcomes. The aim of this study was to investigate the effects of CGM device type/calibration and CGM sensor location on results from DFA. Methods This study uses CGM data from critically ill patients who were each monitored concurrently using Medtronic iPro2s on the thigh and abdomen and a Medtronic Guardian REAL-Time on the abdomen. This allowed interdevice/calibration type and intersensor site variation to be assessed. Detrended fluctuation analysis is a technique that has previously been used to determine the complexity of CGM data in critically ill patients. Two variants of DFA, monofractal and multifractal, were used to assess the complexity of sensor glucose data as well as the precalibration raw sensor current. Monofractal DFA produces a scaling exponent (H), where H is inversely related to complexity. The results of multifractal DFA are presented graphically by the multifractal spectrum. Results From the 10 patients recruited, 26 CGM devices produced data suitable for analysis. The values of H from abdominal iPro2 data were 0.10 (0.03–0.20) higher than those from Guardian REAL-Time data, indicating consistently lower complexities in iPro2 data. However, repeating the analysis on the raw sensor current showed little or no difference in complexity. Sensor site had little effect on the scaling exponents in this data set. Finally, multifractal DFA revealed no significant associations between the multifractal spectrums and CGM device type/calibration or sensor location. Conclusions Monofractal DFA results are dependent on the device/calibration used to obtain CGM data, but sensor location has little impact. Future studies of glucose complexity should consider the findings presented here when designing their investigations. PMID:24351175

Performance analysis of the OneTouch UltraVue blood glucose monitoring system.

PubMed

Chang, Anna; Orth, Alice; Le, Bryan; Menchavez, Perla; Miller, Lupe

2009-09-01

OneTouch UltraVue is a new meter for self-monitoring of blood glucose that includes a color display, used-strip ejector, and no-button interface. The system uses an electrochemical biosensor technology based on glucose oxidase chemistry to detect glucose concentrations from 20 to 600 mg/dl (1.1 to 33.3 mmol/liter). Accuracy and reproducibility were evaluated over a wide range of glucose concentrations according to standard criteria. Clinical accuracy was assessed by health care providers (HCPs) in two studies and by diabetes patients in the second study. Reference glucose levels were determined by a YSI 2300 analyzer. Same-day reproducibility and day-to-day reproducibility were also evaluated. In the accuracy studies, 99.7% and 98.7% of tests by HCPs and 97.0% of tests by patients were within +/-15 mg/dl (+/-0.8 mmol/liter) of the YSI reference for blood glucose <75 mg/dl (<4.2 mmol/liter), and within +/-20% for blood glucose > or =75 mg/dl (> or =4.2 mmol/liter), respectively. Consensus error grid analysis showed that 99.7% and 95.3% of tests by HCPs and 97.0% of tests by patients fell within zone A (i.e., has no effect on clinical action); all other results were in zone B (i.e., altered clinical action, little or no effect on clinical outcome). In the reproducibility studies, the standard deviation was <1.5 mg/dl (<0.1 mmol/liter) for glucose concentrations <100 mg/dl (<5.6 mmol/liter), and the coefficient of variation was <2% for concentrations > or = 100 mg/dl (> or =5.6 mmol/liter). OneTouch UltraVue meets standard acceptability criteria for accuracy and reproducibility across a wide range of glucose concentrations. Its simple interface and lack of contact with used strips make it a viable option for older patients and their caregivers. 2009 Diabetes Technology Society.

Performance Analysis of the OneTouch® UltraVue™ Blood Glucose Monitoring System

PubMed Central

Chang, Anna; Orth, Alice; Le, Bryan; Menchavez, Perla; Miller, Lupe

2009-01-01

Background OneTouch® UltraVue™ is a new meter for self-monitoring of blood glucose that includes a color display, used-strip ejector, and no-button interface. The system uses an electrochemical biosensor technology based on glucose oxidase chemistry to detect glucose concentrations from 20 to 600 mg/dl (1.1 to 33.3 mmol/liter). Methods Accuracy and reproducibility were evaluated over a wide range of glucose concentrations according to standard criteria. Clinical accu-racy was assessed by health care providers (HCPs) in two studies and by diabetes patients in the second study. Reference glucose lev-els were determined by a YSI 2300 analyzer. Same-day reproducibility and day-to-day reproducibility were also evaluated. Results In the accuracy studies, 99.7% and 98.7% of tests by HCPs and 97.0% of tests by patients were within ±15 mg/dl (±0.8 mmol/liter) of the YSI reference for blood glucose <75 mg/dl (<4.2 mmol/liter), and within ±20% for blood glucose ≥75 mg/dl (≥4.2 mmol/liter), respectively. Consensus error grid analysis showed that 99.7% and 95.3% of tests by HCPs and 97.0% of tests by patients fell within zone A (i.e., has no effect on clinical action); all other results were in zone B (i.e., altered clinical action, little or no effect on clini-cal outcome). In the reproducibility studies, the standard deviation was <1.5 mg/dl (<0.1 mmol/liter) for glucose concentra-tions <100 mg/dl (<5.6 mmol/liter), and the coefficient of variation was <2% for concentrations ≥100 mg/dl (≥5.6 mmol/liter). Conclusions OneTouch UltraVue meets standard acceptability criteria for accuracy and reproducibility across a wide range of glucose concentra-tions. Its simple interface and lack of contact with used strips make it a viable option for older patients and their caregivers. PMID:20144431

Mapping glucose-mediated gut-to-brain signalling pathways in humans☆

PubMed Central

Little, Tanya J.; McKie, Shane; Jones, Richard B.; D'Amato, Massimo; Smith, Craig; Kiss, Orsolya; Thompson, David G.; McLaughlin, John T.

2014-01-01

Objectives Previous fMRI studies have demonstrated that glucose decreases the hypothalamic BOLD response in humans. However, the mechanisms underlying the CNS response to glucose have not been defined. We recently demonstrated that the slowing of gastric emptying by glucose is dependent on activation of the gut peptide cholecystokinin (CCK1) receptor. Using physiological functional magnetic resonance imaging this study aimed to determine the whole brain response to glucose, and whether CCK plays a central role. Experimental design Changes in blood oxygenation level-dependent (BOLD) signal were monitored using fMRI in 12 healthy subjects following intragastric infusion (250 ml) of: 1 M glucose + predosing with dexloxiglumide (CCK1 receptor antagonist), 1 M glucose + placebo, or 0.9% saline (control) + placebo, in a single-blind, randomised fashion. Gallbladder volume, blood glucose, insulin, and GLP-1 and CCK concentrations were determined. Hunger, fullness and nausea scores were also recorded. Principal observations Intragastric glucose elevated plasma glucose, insulin, and GLP-1, and reduced gall bladder volume (an in vivo assay for CCK secretion). Glucose decreased BOLD signal, relative to saline, in the brainstem and hypothalamus as well as the cerebellum, right occipital cortex, putamen and thalamus. The timing of the BOLD signal decrease was negatively correlated with the rise in blood glucose and insulin levels. The glucose + dex arm highlighted a CCK1-receptor dependent increase in BOLD signal only in the motor cortex. Conclusions Glucose induces site-specific differences in BOLD response in the human brain; the brainstem and hypothalamus show a CCK1 receptor-independent reduction which is likely to be mediated by a circulatory effect of glucose and insulin, whereas the motor cortex shows an early dexloxiglumide-reversible increase in signal, suggesting a CCK1 receptor-dependent neural pathway. PMID:24685436

Continuous Glucose Monitoring in Female NOD Mice Reveals Daily Rhythms and a Negative Correlation With Body Temperature.

PubMed

Korstanje, Ron; Ryan, Jennifer L; Savage, Holly S; Lyons, Bonnie L; Kane, Kevin G; Sukoff Rizzo, Stacey J

2017-09-01

Previous studies with continuous glucose monitoring in mice have been limited to several days or weeks, with the mouse's physical attachment to the equipment affecting behavior and measurements. In the current study, we measured blood glucose and body temperature at 10-second intervals for 12 weeks in a cohort of NOD/ShiLtJ female mice using wireless telemetry. This allowed us to obtain a high-resolution profile of the circadian rhythm of these two parameters and the onset of hyperglycemic development in real time. The most striking observations were the elevated nocturnal concentrations of glucose into the diabetic range days before elevations in diurnal glucose (when glucose concentrations are historically measured) and the strong, negative correlation between elevated blood glucose concentrations and body temperature with a steady decline of the body temperature with diabetes development. Taken together, this technological advancement provides improved resolution in the study of the disease trajectory of diabetes in mouse models, including relevant translatability to the current technologies of continuous glucose monitoring now regularly used in patients. Copyright © 2017 Endocrine Society.

A history of continuous glucose monitors (CGMs) in self-monitoring of diabetes mellitus.

PubMed

Olczuk, David; Priefer, Ronny

Self-monitoring of glucose for individuals afflicted with diabetes mellitus has allowed patients to take control of their disease and thus directly affect the outcomes related to it. It has been almost a century since the first test to monitor one's sugar was developed; that being a urine test. The most well-known and prominent medical device for monitor blood glucose for individuals with diabetes are the finger-prick devices. This itself is an approximately 50year old technology. More recently has been the introduction of continuous glucose monitors (CGMs) which entered the market place in the last year of the 20th century. As this technology has been further refined and improved, limitations associated with it have decreased. The scope of this review is to present a brief history of CGMs, both with the development of these medical devices and the challenges/limitations that they have shown. Copyright © 2017 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Diabetic Children Need Care but Can Lead Normal Lives.

ERIC Educational Resources Information Center

PTA Today, 1984

1984-01-01

Children with diabetes can take part in normal school activities as long as they maintain control over their blood sugar level through a technique called self blood-glucose monitoring. Parents can work with teachers to see that dietary and medicinal needs are accommodated. (PP)

Use of the continuous glucose monitoring system in Goettingen Minipigs, with a special focus on the evaluation of insulin-dependent diabetes.

PubMed

Strauss, A; Tiurbe, C; Chodnevskaja, I; Thiede, A; Timm, S; Ulrichs, K; Moskalenko, V

2008-03-01

Adult pig islet isolation has greatly improved in the past few years. Islet grafts may now be tested in large animals. Continuous Glucose Monitoring System (CGMS) was applied to diabetic Goettingen Minipigs (GMP) to improve the management of hyperglycemia and hypoglycemia and their welfare before transplantation. GMP (25-35 kg) received a minipig diet once daily. Diabetes was induced by streptozotocin (STZ; 150 mg/kg intravenous [IV]; n = 5) or by surgical pancreatectomy (PGMP; n = 3). Interstitial glucose concentration (IGC) was monitored continuously with an implanted sensor; CGMS was calibrated using conventional blood glucose tests 3-4 times per day; CGMS data were fed into the monitor memory and analyzed using CGMS software. Glucose sensors were handled accurately. Diabetes occurred 2-3 days after STZ or immediately after pancreatectomy with basal C-peptide secretion of <0.4 ng/mL (measured using intravenous glucose tolerance test) and prompt loss of body weight. Insulin substitution was necessary to keep the GMP in good condition for up to 5-6 months, with stable body weight and normal behavior. Some GMP became hypoglycemic, which was only documented by CGMS, but not by conventional glucose assays. Tight glucose control and substitution of exocrine enzymes (Creon 25,000 E/d) reduced morbidity of the PGMP, which was then comparable with that of STZ-GMP. The CGMS, developed for humans, is equally suitable for the 2 GMP diabetes models. Close-meshed glucose monitoring and insulin treatment improved the general condition of the diabetic GMP, ie, the islet graft recipients, and will thus greatly add to posttransplantation success.

Continuous Glucose Monitoring (CGM) or Blood Glucose Monitoring (BGM): Interactions and Implications.

PubMed

Heinemann, Lutz

2018-04-01

At the 2017 10th annual International Conference on Advanced Technologies and Treatments for Diabetes (ATTD) in Paris, France, four speakers presented their perspectives on the roles of continuous glucose monitoring (CGM) and of blood glucose monitoring (BGM) in patient management within one symposium. These presentations included discussions of the differences in the accuracy of CGM and BGM, a clinical perspective on the physiological reasons behind differences in CGM and BGM values, and an overview of the impact of variations in device accuracy on patients with diabetes. Subsequently a short summary of these presentations is given, highlighting the value of good accuracy of BGM or CGM systems and the ongoing need for standardization. The important role of both BGM and CGM in patient management was a theme across all presentations.

New Criteria for Assessing the Accuracy of Blood Glucose Monitors Meeting, October 28, 2011

PubMed Central

Walsh, John; Roberts, Ruth; Vigersky, Robert A.; Schwartz, Frank

2012-01-01

Glucose meters (GMs) are routinely used for self-monitoring of blood glucose by patients and for point-of-care glucose monitoring by health care providers in outpatient and inpatient settings. Although widely assumed to be accurate, numerous reports of inaccuracies with resulting morbidity and mortality have been noted. Insulin dosing errors based on inaccurate GMs are most critical. On October 28, 2011, the Diabetes Technology Society invited 45 diabetes technology clinicians who were attending the 2011 Diabetes Technology Meeting to participate in a closed-door meeting entitled New Criteria for Assessing the Accuracy of Blood Glucose Monitors. This report reflects the opinions of most of the attendees of that meeting. The Food and Drug Administration (FDA), the public, and several medical societies are currently in dialogue to establish a new standard for GM accuracy. This update to the FDA standard is driven by improved meter accuracy, technological advances (pumps, bolus calculators, continuous glucose monitors, and insulin pens), reports of hospital and outpatient deaths, consumer complaints about inaccuracy, and research studies showing that several approved GMs failed to meet FDA or International Organization for Standardization standards in post-approval testing. These circumstances mandate a set of new GM standards that appropriately match the GMs’ analytical accuracy to the clinical accuracy required for their intended use, as well as ensuring their ongoing accuracy following approval. The attendees of the New Criteria for Assessing the Accuracy of Blood Glucose Monitors meeting proposed a graduated standard and other methods to improve GM performance, which are discussed in this meeting report. PMID:22538160

New Criteria for Assessing the Accuracy of Blood Glucose Monitors meeting, October 28, 2011.

PubMed

Walsh, John; Roberts, Ruth; Vigersky, Robert A; Schwartz, Frank

2012-03-01

Glucose meters (GMs) are routinely used for self-monitoring of blood glucose by patients and for point-of-care glucose monitoring by health care providers in outpatient and inpatient settings. Although widely assumed to be accurate, numerous reports of inaccuracies with resulting morbidity and mortality have been noted. Insulin dosing errors based on inaccurate GMs are most critical. On October 28, 2011, the Diabetes Technology Society invited 45 diabetes technology clinicians who were attending the 2011 Diabetes Technology Meeting to participate in a closed-door meeting entitled New Criteria for Assessing the Accuracy of Blood Glucose Monitors. This report reflects the opinions of most of the attendees of that meeting. The Food and Drug Administration (FDA), the public, and several medical societies are currently in dialogue to establish a new standard for GM accuracy. This update to the FDA standard is driven by improved meter accuracy, technological advances (pumps, bolus calculators, continuous glucose monitors, and insulin pens), reports of hospital and outpatient deaths, consumer complaints about inaccuracy, and research studies showing that several approved GMs failed to meet FDA or International Organization for Standardization standards in postapproval testing. These circumstances mandate a set of new GM standards that appropriately match the GMs' analytical accuracy to the clinical accuracy required for their intended use, as well as ensuring their ongoing accuracy following approval. The attendees of the New Criteria for Assessing the Accuracy of Blood Glucose Monitors meeting proposed a graduated standard and other methods to improve GM performance, which are discussed in this meeting report. © 2012 Diabetes Technology Society.

Soft, smart contact lenses with integrations of wireless circuits, glucose sensors, and displays

PubMed Central

Park, Jihun; Kim, Joohee; Kim, So-Yun; Cheong, Woon Hyung; Jang, Jiuk; Park, Young-Geun; Na, Kyungmin; Kim, Yun-Tae; Heo, Jun Hyuk; Lee, Chang Young; Lee, Jung Heon; Bien, Franklin; Park, Jang-Ung

2018-01-01

Recent advances in wearable electronics combined with wireless communications are essential to the realization of medical applications through health monitoring technologies. For example, a smart contact lens, which is capable of monitoring the physiological information of the eye and tear fluid, could provide real-time, noninvasive medical diagnostics. However, previous reports concerning the smart contact lens have indicated that opaque and brittle components have been used to enable the operation of the electronic device, and this could block the user’s vision and potentially damage the eye. In addition, the use of expensive and bulky equipment to measure signals from the contact lens sensors could interfere with the user’s external activities. Thus, we report an unconventional approach for the fabrication of a soft, smart contact lens in which glucose sensors, wireless power transfer circuits, and display pixels to visualize sensing signals in real time are fully integrated using transparent and stretchable nanostructures. The integration of this display into the smart lens eliminates the need for additional, bulky measurement equipment. This soft, smart contact lens can be transparent, providing a clear view by matching the refractive indices of its locally patterned areas. The resulting soft, smart contact lens provides real-time, wireless operation, and there are in vivo tests to monitor the glucose concentration in tears (suitable for determining the fasting glucose level in the tears of diabetic patients) and, simultaneously, to provide sensing results through the contact lens display. PMID:29387797

Soft, smart contact lenses with integrations of wireless circuits, glucose sensors, and displays.

PubMed

Park, Jihun; Kim, Joohee; Kim, So-Yun; Cheong, Woon Hyung; Jang, Jiuk; Park, Young-Geun; Na, Kyungmin; Kim, Yun-Tae; Heo, Jun Hyuk; Lee, Chang Young; Lee, Jung Heon; Bien, Franklin; Park, Jang-Ung

2018-01-01

Recent advances in wearable electronics combined with wireless communications are essential to the realization of medical applications through health monitoring technologies. For example, a smart contact lens, which is capable of monitoring the physiological information of the eye and tear fluid, could provide real-time, noninvasive medical diagnostics. However, previous reports concerning the smart contact lens have indicated that opaque and brittle components have been used to enable the operation of the electronic device, and this could block the user's vision and potentially damage the eye. In addition, the use of expensive and bulky equipment to measure signals from the contact lens sensors could interfere with the user's external activities. Thus, we report an unconventional approach for the fabrication of a soft, smart contact lens in which glucose sensors, wireless power transfer circuits, and display pixels to visualize sensing signals in real time are fully integrated using transparent and stretchable nanostructures. The integration of this display into the smart lens eliminates the need for additional, bulky measurement equipment. This soft, smart contact lens can be transparent, providing a clear view by matching the refractive indices of its locally patterned areas. The resulting soft, smart contact lens provides real-time, wireless operation, and there are in vivo tests to monitor the glucose concentration in tears (suitable for determining the fasting glucose level in the tears of diabetic patients) and, simultaneously, to provide sensing results through the contact lens display.

The use and efficacy of continuous glucose monitoring in type 1 diabetes treated with insulin pump therapy: a randomised controlled trial.

PubMed

Battelino, T; Conget, I; Olsen, B; Schütz-Fuhrmann, I; Hommel, E; Hoogma, R; Schierloh, U; Sulli, N; Bolinder, J

2012-12-01

The aim of this multicentre, randomised, controlled crossover study was to determine the efficacy of adding continuous glucose monitoring (CGM) to insulin pump therapy (CSII) in type 1 diabetes. Children and adults (n = 153) on CSII with HbA(1c) 7.5-9.5% (58.5-80.3 mmol/mol) were randomised to (CGM) a Sensor On or Sensor Off arm for 6 months. After 4 months' washout, participants crossed over to the other arm for 6 months. Paediatric and adult participants were separately electronically randomised through the case report form according to a predefined randomisation sequence in eight secondary and tertiary centres. The primary outcome was the difference in HbA(1c) levels between arms after 6 months. Seventy-seven participants were randomised to the On/Off sequence and 76 to the Off/On sequence; all were included in the primary analysis. The mean difference in HbA(1c) was -0.43% (-4.74 mmol/mol) in favour of the Sensor On arm (8.04% [64.34 mmol/mol] vs 8.47% [69.08 mmol/mol]; 95% CI -0.32%, -0.55% [-3.50, -6.01 mmol/mol]; p < 0.001). Following cessation of glucose sensing, HbA(1c) reverted to baseline levels. Less time was spent with sensor glucose <3.9 mmol/l during the Sensor On arm than in the Sensor Off arm (19 vs 31 min/day; p = 0.009). The mean number of daily boluses increased in the Sensor On arm (6.8 ± 2.5 vs 5.8 ± 1.9, p < 0.0001), together with the frequency of use of the temporary basal rate (0.75 ± 1.11 vs 0.26 ± 0.47, p < 0.0001) and manual insulin suspend (0.91 ± 1.25 vs 0.70 ± 0.75, p < 0.018) functions. Four vs two events of severe hypoglycaemia occurred in the Sensor On and Sensor Off arm, respectively (p = 0.40). Continuous glucose monitoring was associated with decreased HbA(1c) levels and time spent in hypoglycaemia in individuals with type 1 diabetes using CSII. More frequent self-adjustments of insulin therapy may have contributed to these effects.

Continuous glucose monitoring adds information beyond HbA1c in well-controlled diabetes patients with early cardiovascular autonomic neuropathy.

PubMed

Fleischer, Jesper; Laugesen, Esben; Cichosz, Simon Lebech; Hoeyem, Pernille; Dejgaard, Thomas Fremming; Poulsen, Per Loegstrup; Tarnow, Lise; Hansen, Troels Krarup

2017-09-01

Hyperglycemia as evaluated by HbA1c is a risk factor for the development of cardiovascular autonomic neuropathy (CAN). The aim of the present study was to investigate whether continuous glucose monitoring (CGM) may add information beyond HbA1c in patients with type 2 diabetes and CAN. 81 patients with type 2 diabetes (43 men, mean age 58±11year, HbA1c 6.6±0.5%). Patients were tested for CAN using cardiovascular reflex tests (response to standing, deep breathing and Valsalva maneuver) and underwent CGM for three days. CAN was defined as early (one test abnormal), or manifest (two or three tests abnormal). Twenty patients had early CAN and two patients had manifest CAN. Blood pressure, HbA1c, cholesterol levels and smoking habits were comparable in patients with vs. without CAN. Post-breakfast glycemic peak was significantly higher in patients with CAN (peak 207 vs 176mg/dL, P=0.009). Furthermore, the nocturnal glucose drop and dawn glucose was significantly higher in patients with CAN compared with patients without CAN (mean 134 vs. 118mg/dL, P=0.017 and mean 143 vs. 130mg/dL, P=0.045, respectively). Removing the two patients with manifest CAN from the statistical analysis didn't change the results. These findings emphasize the importance of monitoring glucose patterns over 24-h and not only rely on HbA1c as therapeutic target in patients with type 2 diabetes and CAN. Copyright © 2017 Elsevier Inc. All rights reserved.

Treatment intensification without improved HbA1c levels in children and adolescents with Type 1 diabetes mellitus.

PubMed

Sildorf, S M; Hertel, N T; Thomsen, J; Fredheim, S; Hastrup, H; Pipper, C; Hertz, B; Svensson, J

2016-04-01

To examine trends in diabetes treatment in Danish children and adolescents with Type 1 diabetes mellitus, comparing treatment intensity with metabolic outcomes in the population, and to describe the challenges of population-based registries in a clinical setting with rapidly changing treatment methods. This observational study is based on the Danish national population registry of childhood diabetes, which includes 99% of children diagnosed with Type 1 diabetes before the age of 15 years. We included 4527 people diagnosed between 2000 and 2012. Self-monitored blood glucose measurements, insulin injections/boluses, treatment method and metabolic control quantifications were analysed and adjusted for the effects of gender and ethnicity, the combined effect of age, visit year and duration, and for the random effects of individual and hospital settings. Treatment was intensified via an increasing number of self-monitored blood glucose measurements and injections/boluses. More than six injections/boluses and an increased number of self-monitored blood glucose measurements were significantly associated with lower metabolic control. No reduction, however, in the overall mean HbA1c concentration was observed between 2005 [66 mmol/mol (8.2%)] and 2012 [65 mmol/mol (8.1%)]. Changed registration practices in 2009 introduced artificial jumps in data. Intensifying treatment alone does not lead to improved metabolic control in the overall population despite the appearance of lower HbA1c in individuals with a greater number of self-monitored blood glucose measurements and injections/boluses. The contradictory results reflect difficulties in using observational studies to predict results of intervention in the individual. Data collected from population-based registries need to be adjusted continuously to reflect changes in care. © 2015 Diabetes UK.

A low calorie morning meal prevents the decline of hepatic glycogen stores: a pilot in vivo (13)C magnetic resonance study.

PubMed

Bawden, S J; Stephenson, M C; Ciampi, E; Hunter, K; Marciani, L; Spiller, R C; Aithal, G P; Morris, P G; Macdonald, I A; Gowland, P A

2014-09-01

Previous studies have reported a meal-induced rise in hepatic glycogen stores from baseline levels following a fast and it is generally assumed that glycogen levels rise steadily following meals throughout the day. However, measurements are normally taken in conditions that are not typical of the Western breakfast, which is relatively carbohydrate rich with a lower calorific content than most experimental test meals. As such, little is known about the normal metabolic response to a realistic, low calorie morning meal. Therefore, the aim of this pilot study was to evaluate the effects of a low dose oral glucose intake on hepatic glycogen levels following an overnight fast in healthy subjects. Glycogen levels were monitored in vivo using (13)C Magnetic Resonance Spectroscopy at baseline and hourly for 4 hours following either a 50 g glucose drink (773 kJ) or a control drink (0 kJ) given over two different visits. During the control visit hepatic glycogen levels decreased throughout the experiment with statistically significant decreases from baseline at 190 minutes (P < 0.05) and 250 minutes (P < 0.05). By contrast, the low dose glucose intake maintained glycogen concentrations with no significant decrease from baseline over 4 hours. A comparison between visits revealed that mean glycogen concentrations were significantly greater during the glucose visit (control visit, AUC = 218 ± 39 mol L(-1) min(-1); glucose visit, AUC = 305 ± 49 mol L(-1) min(-1); P < 0.05). Liver volume decreased significantly from baseline at 180 minutes (P < 0.05) post consumption in both groups, with no significant difference found between visits. Gastric content volumes were significantly higher for the glucose visit immediately following consumption (P < 0.001) and at 60 minutes (P = 0.007) indicating slower gastric emptying for the glucose compared with the control. In conclusion, following an overnight fast, a low dose oral glucose challenge prevents a reduction in hepatic glycogen content but does not increase it above fasted levels.

A closed-loop artificial pancreas using a proportional integral derivative with double phase lead controller based on a new nonlinear model of glucose metabolism.

PubMed

Abbes, Ilham Ben; Richard, Pierre-Yves; Lefebvre, Marie-Anne; Guilhem, Isabelle; Poirier, Jean-Yves

2013-05-01

Most closed-loop insulin delivery systems rely on model-based controllers to control the blood glucose (BG) level. Simple models of glucose metabolism, which allow easy design of the control law, are limited in their parametric identification from raw data. New control models and controllers issued from them are needed. A proportional integral derivative with double phase lead controller was proposed. Its design was based on a linearization of a new nonlinear control model of the glucose-insulin system in type 1 diabetes mellitus (T1DM) patients validated with the University of Virginia/Padova T1DM metabolic simulator. A 36 h scenario, including six unannounced meals, was tested in nine virtual adults. A previous trial database has been used to compare the performance of our controller with their previous results. The scenario was repeated 25 times for each adult in order to take continuous glucose monitoring noise into account. The primary outcome was the time BG levels were in target (70-180 mg/dl). Blood glucose values were in the target range for 77% of the time and below 50 mg/dl and above 250 mg/dl for 0.8% and 0.3% of the time, respectively. The low blood glucose index and high blood glucose index were 1.65 and 3.33, respectively. The linear controller presented, based on the linearization of a new easily identifiable nonlinear model, achieves good glucose control with low exposure to hypoglycemia and hyperglycemia. © 2013 Diabetes Technology Society.

Estimating Plasma Glucose from Interstitial Glucose: The Issue of Calibration Algorithms in Commercial Continuous Glucose Monitoring Devices

PubMed Central

Rossetti, Paolo; Bondia, Jorge; Vehí, Josep; Fanelli, Carmine G.

2010-01-01

Evaluation of metabolic control of diabetic people has been classically performed measuring glucose concentrations in blood samples. Due to the potential improvement it offers in diabetes care, continuous glucose monitoring (CGM) in the subcutaneous tissue is gaining popularity among both patients and physicians. However, devices for CGM measure glucose concentration in compartments other than blood, usually the interstitial space. This means that CGM need calibration against blood glucose values, and the accuracy of the estimation of blood glucose will also depend on the calibration algorithm. The complexity of the relationship between glucose dynamics in blood and the interstitial space, contrasts with the simplistic approach of calibration algorithms currently implemented in commercial CGM devices, translating in suboptimal accuracy. The present review will analyze the issue of calibration algorithms for CGM, focusing exclusively on the commercially available glucose sensors. PMID:22163505

Blood glucose monitoring skills in children with Type I diabetes.

PubMed

Perwien, A R; Johnson, S B; Dymtrow, D; Silverstein, J

2000-06-01

While blood glucose monitoring has become increasingly important in diabetes care, studies have yet to address the accuracy of youngsters' performance of blood glucose testing with current reflectance meters. The present study examined testing skills and predictors of accurate testing skills in a sample of 7-14-year-old children attending a summer camp for youth with diabetes (n=266). A 15-item behavior observational skill test was used to assess accuracy of blood glucose monitoring skills with reflectance meters. Accurate performance of individual skills ranged between 14.6% and 99.6% for the sample. However, a number of children made critical errors (errors that were likely to lead to inaccurate blood glucose testing results). When duration of diabetes and metabolic control were controlled, female gender, older age, experience with a particular meter, and absence of hypoglycemia at the time of testing were positively associated with accurate skill performance. Findings suggest that younger children, children using a new blood glucose testing meter, and children suspected of having hypoglycemia should be supervised and observed when testing. Although all young children should be supervised when blood glucose testing, boys may need closer supervision until an older age than girls. This study underscores the need for health care providers to periodically observe children's blood glucose monitoring techniques to assure accurate testing habits and to correct problematic testing behaviors.

Glucose-responsive insulin delivery for type 1 diabetes: The artificial pancreas story.

PubMed

Bally, Lia; Thabit, Hood; Hovorka, Roman

2018-06-15

Insulin replacement therapy is integral to the management of type 1 diabetes, which is characterised by absolute insulin deficiency. Optimal glycaemic control, as assessed by glycated haemoglobin, and avoidance of hyper- and hypoglycaemic excursions have been shown to prevent diabetes-related complications. Insulin pump use has increased considerably over the past decade with beneficial effects on glycaemic control, quality of life and treatment satisfaction. The advent and progress of ambulatory glucose sensor technology has enabled continuous glucose monitoring based on real-time glucose levels to be integrated with insulin therapy. Low glucose and predictive low glucose suspend systems are currently used in clinical practice to mitigate against hypoglycaemia, and provide the first step towards feedback glucose control. The more advanced technology approach, an artificial pancreas or a closed-loop system, gradually increases and decreases insulin delivery in a glucose-responsive fashion to mitigate against hyper- and hypoglycaemia. Randomised outpatient clinical trials over the past 5 years have demonstrated the feasibility, safety and efficacy of the approach, and the recent FDA approval of the first single hormone closed-loop system establishes a new standard of care for people with type 1 diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

A Tele-Behavioral Health Intervention to Reduce Depression, Anxiety, and Stress and Improve Diabetes Self-Management.

PubMed

Mochari-Greenberger, Heidi; Vue, Lee; Luka, Andi; Peters, Aimee; Pande, Reena L

2016-08-01

Depression is prevalent among individuals with diabetes and associated with suboptimal self-management. Little is known about the feasibility and potential impact of tele-behavioral therapy to improve depressive symptoms and self-management among diabetes patients. This was a retrospective observational study of consecutive graduates enrolled in a national 8-week diabetes behavioral telehealth program between August 1, 2014, and January 31, 2015 (N = 466; mean age 56.8 ± 5.0 years; 56% female). Participant characteristics (demographics, comorbidities) were obtained by standardized questionnaire. Depression, anxiety, and stress symptoms (DASS; validated Depression Anxiety and Stress Scale 21 survey), and glucose self-testing frequency and values (point-of-care monitor) were measured at program start and completion. Changes in DASS severity and glucose self-testing frequency were assessed by chi-square tests. Changes in DASS and blood glucose levels were evaluated by paired t-tests. At baseline, approximately one in three participants had elevated depression (32%), anxiety (33%), or stress (31%) scores. Significant reductions in average DASS, depression (-8.8), anxiety (-6.9), and stress (-9.9), scores were observed at graduation among those with elevated baseline scores (p < 0.0001); most (≥80%) improved to less severe depression, anxiety, or stress categories. Improved glucose self-testing frequency (69% vs. 60% tested ≥once per week; p = 0.0005) and significant reductions in mean morning glucose levels (-12.3 mg/dL; p = 0.0002) were observed from baseline to graduation. Participants with normal versus non-normal depression scores were more likely to have lower (

Blood Glucose Monitoring Devices

MedlinePlus

... of interferences ability to transmit data to a computer cost of the meter cost of the test ... Performance FDA expands indication for continuous glucose monitoring system, first to replace fingerstick testing for diabetes treatment ...

Promoting health and reducing costs: a role for reform of self-monitoring of blood glucose provision within the National Health Service.

PubMed

Leigh, S; Idris, I; Collins, B; Granby, P; Noble, M; Parker, M

2016-05-01

To determine the cost-effectiveness of all options for the self-monitoring of blood glucose funded by the National Health Service, providing guidance for disinvestment and testing the hypothesis that advanced meter features may justify higher prices. Using data from the Health and Social Care Information Centre concerning all 8 340 700 self-monitoring of blood glucose-related prescriptions during 2013/2014, we conducted a cost-minimization analysis, considering both strip and lancet costs, including all clinically equivalent technologies for self-monitoring of blood glucose, as determined by the ability to meet ISO-15197:2013 guidelines for meter accuracy. A total of 56 glucose monitor, test strip and lancet combinations were identified, of which 38 met the required accuracy standards. Of these, the mean (range) net ingredient costs for test strips and lancets were £0.27 (£0.14-£0.32) and £0.04 (£0.02-£0.05), respectively, resulting in a weighted average of £0.28 (£0.18-£0.37) per test. Systems providing four or more advanced features were priced equal to those providing just one feature. A total of £12 m was invested in providing 42 million self-monitoring of blood glucose tests with systems that fail to meet acceptable accuracy standards, and efficiency savings of £23.2 m per annum are achievable if the National Health Service were to disinvest from technologies providing lesser functionality than available alternatives, but at a much higher price. The study uncovered considerable variation in the price paid by the National Health Service for self-monitoring of blood glucose, which could not be explained by the availability of advanced meter features. A standardized approach to self-monitoring of blood glucose prescribing could achieve significant efficiency savings for the National Health Service, whilst increasing overall utilisation and improving safety for those currently using systems that fail to meet acceptable standards for measurement accuracy. © 2015 Diabetes UK.

Physical activity measured by physical activity monitoring system correlates with glucose trends reconstructed from continuous glucose monitoring.

PubMed

Zecchin, Chiara; Facchinetti, Andrea; Sparacino, Giovanni; Dalla Man, Chiara; Manohar, Chinmay; Levine, James A; Basu, Ananda; Kudva, Yogish C; Cobelli, Claudio

2013-10-01

In type 1 diabetes mellitus (T1DM), physical activity (PA) lowers the risk of cardiovascular complications but hinders the achievement of optimal glycemic control, transiently boosting insulin action and increasing hypoglycemia risk. Quantitative investigation of relationships between PA-related signals and glucose dynamics, tracked using, for example, continuous glucose monitoring (CGM) sensors, have been barely explored. In the clinic, 20 control and 19 T1DM subjects were studied for 4 consecutive days. They underwent low-intensity PA sessions daily. PA was tracked by the PA monitoring system (PAMS), a system comprising accelerometers and inclinometers. Variations on glucose dynamics were tracked estimating first- and second-order time derivatives of glucose concentration from CGM via Bayesian smoothing. Short-time effects of PA on glucose dynamics were quantified through the partial correlation function in the interval (0, 60 min) after starting PA. Correlation of PA with glucose time derivatives is evident. In T1DM, the negative correlation with the first-order glucose time derivative is maximal (absolute value) after 15 min of PA, whereas the positive correlation is maximal after 40-45 min. The negative correlation between the second-order time derivative and PA is maximal after 5 min, whereas the positive correlation is maximal after 35-40 min. Control subjects provided similar results but with positive and negative correlation peaks anticipated of 5 min. Quantitative information on correlation between mild PA and short-term glucose dynamics was obtained. This represents a preliminary important step toward incorporation of PA information in more realistic physiological models of the glucose-insulin system usable in T1DM simulators, in development of closed-loop artificial pancreas control algorithms, and in CGM-based prediction algorithms for generation of hypoglycemic alerts.

Achievement of target A1C levels with negligible hypoglycemia and low glucose variability in youth with short-term type 1 diabetes and residual β-cell function.

PubMed

Sherr, Jennifer; Tamborlane, William V; Xing, Dongyuan; Tsalikian, Eva; Mauras, Nelly; Buckingham, Bruce; White, Neil H; Arbelaez, Ana Maria; Beck, Roy W; Kollman, Craig; Ruedy, Katrina

2012-04-01

To determine exposure to hyper- and hypoglycemia using blinded continuous glucose monitoring (CGM) profiles in youth with type 1 diabetes (T1D) with residual β-cell function during the first year of insulin treatment. Blinded, 3-7 day CGM profiles were obtained in 16 short-term T1D patients (age 8-18 years, T1D duration 6-52 weeks) who had peak C-peptide levels ranging from 0.46 to 1.96 nmol/L during a mixed-meal tolerance test. Results in this short-term group were compared with those in 34 patients with well-controlled, longer-term T1D (duration ≥5 years), matched for age and A1C with the short-term T1D group, and with those in 26 age-matched nondiabetic individuals. Despite matching for A1C, and therefore similar mean sensor glucose levels in the two T1D groups, short-term T1D participants had a lower frequency of hypoglycemia (0.3 vs. 7.6%, P < 0.001), a trend toward less hyperglycemia (17 vs. 32%, P = 0.15), and a greater percentage in the target range (median 77 vs. 60%, P = 0.02). Indeed, the percentage of sensor glucose levels ≤70 mg/dL in the short-term T1D group (0.3%) did not differ from those in the nondiabetic group (1.7%, P = 0.73). The coefficient of variation of sensor glucose levels (an index of glucose variability) was lower in short-term vs. longer-term T1D participants (27 vs. 42%, respectively, P < 0.001). In youth with short-term T1D who retain residual β-cell function, there is negligible exposure to hypoglycemia and lower glucose variability than in youth with well-controlled T1D of longer duration.

Ultrasound mediated transdermal insulin delivery in pigs using a lightweight transducer.

PubMed

Park, E J; Werner, Jacob; Smith, Nadine Barrie

2007-07-01

In previous studies, ultrasound mediated transdermal drug delivery has shown a promising potential as a method for noninvasive drug administration. For prospective future human application, this study was designed to determine the feasibility of lightweight cymbal transducer array as a practical device for noninvasive transdermal insulin delivery in large pigs. Six Yorkshire pigs (100-140 lbs) were divided into two groups. As the control (n = 3), the first group did not receive any ultrasound exposure with the insulin. The second group (n = 3) was treated with ultrasound and insulin at 20 kHz with an I(sptp) = 100 mW/cm(2) at a 20% duty cycle for 60 min. With the pigs in lateral recumbency after anesthesia, the ultrasound transducer with insulin was placed on the axillary area of the pig. At the beginning and every 15 min up to 90 min, the blood glucose level was determined using a glucose monitoring system. To compare the results of individual animals, the change of blood glucose level was normalized to each animal's initial glucose value at the start of the experiment. Although each animal had a different initial glucose level, the mean and standard error for the six animals was 146 +/- 13 mg/dl. For the control group, the blood glucose level increased to 31 +/- 21 mg/dl compared to the initial baseline over the 90 min experiment. However for the ultrasound with insulin treated group, the glucose level decreased to -72 +/- 5 mg/dl at 60 min (p < 0.05) and continued to decrease to -91 +/- 23 mg/dl in 90 min (p < 0.05). The results indicate the feasibility of ultrasound mediated transdermal insulin delivery using the cymbal transducer array in animal with a similar size and weight to a human. Based on these result, the cymbal array has potential as a practical ultrasound system for noninvasive transdermal insulin delivery for diabetes management.

Rapamycin inhibits oxidative/nitrosative stress and enhances angiogenesis in high glucose-treated human umbilical vein endothelial cells: Role of autophagy.

PubMed

Rezabakhsh, Aysa; Ahmadi, Mahdi; Khaksar, Majid; Montaseri, Azadeh; Malekinejad, Hassan; Rahbarghazi, Reza; Garjani, Alireza

2017-09-01

Chronic hyperglycemia is a potent risk factor of abnormal angiogenesis with various tissue diseases. Autophagy, as an alternative cell response, is mostly generated by a vast array of insults. Applying autophagic response contributes to normal cell retrieval circumstance during various insults. We aimed to show whether stimulation/inhibition of autophagy could reduce or exacerbate oxidative status and angiogenic potential in endothelial cells after exposure to 30mM glucose. HUVECs were incubated with the combined regime of 100nM Rapamycin and 30mM glucose over a period of 72h. The effect of rapamycin on cell viability, malondialdehyde levels, and nitric oxide were monitored by convenient assays. Intracellular ROS level was measured by flow cytometric analysis and DCFDA. HUVECs migration and angiogenic properties were assessed using scratch test and tubulogenesis assay. The expression of autophagic modulators LC3, Becline-1 and P62 was measured by using western blotting. Data showed 30mM glucose reduced cell viability, migration and in vitro tubulogenesis and level of ROS and nitric oxide were found to increased (p<0.05). Rapamycin had potential to increase cell survival and significantly decreased the total levels of oxidative stress markers after cell exposure to 30mM glucose (p<0.05). Rapamycin potentially improved the detrimental effect of 30mM glucose on cell migration and tubulogenesis capacity (p<0.05). Effective autophagic response was stimulated by rapamycin by increasing beclin-1, and the LC3-II/I ratio and reducing intracellular P62 level (p<0.05), resulting in the improvement of cell health and function. Together, rapamycin protected HUVECs from damages caused by high glucose concentration. This effect was possibly mediated by autophagy-dependent pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Sleep/wake dependent changes in cortical glucose concentrations.

PubMed

Dash, Michael B; Bellesi, Michele; Tononi, Giulio; Cirelli, Chiara

2013-01-01

Most of the energy in the brain comes from glucose and supports glutamatergic activity. The firing rate of cortical glutamatergic neurons, as well as cortical extracellular glutamate levels, increase with time spent awake and decline throughout non rapid eye movement sleep, raising the question whether glucose levels reflect behavioral state and sleep/wake history. Here chronic (2-3 days) electroencephalographic recordings in the rat cerebral cortex were coupled with fixed-potential amperometry to monitor the extracellular concentration of glucose ([gluc]) on a second-by-second basis across the spontaneous sleep-wake cycle and in response to 3 h of sleep deprivation. [Gluc] progressively increased during non rapid eye movement sleep and declined during rapid eye movement sleep, while during wake an early decline in [gluc] was followed by an increase 8-15 min after awakening. There was a significant time of day effect during the dark phase, when rats are mostly awake, with [gluc] being significantly lower during the last 3-4 h of the night relative to the first 3-4 h. Moreover, the duration of the early phase of [gluc] decline during wake was longer after prolonged wake than after consolidated sleep. Thus, the sleep/wake history may affect the levels of glucose available to the brain upon awakening. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Noninvasive Monitoring of Blood Glucose with Raman Spectroscopy.

PubMed

Pandey, Rishikesh; Paidi, Santosh Kumar; Valdez, Tulio A; Zhang, Chi; Spegazzini, Nicolas; Dasari, Ramachandra Rao; Barman, Ishan

2017-02-21

The successful development of a noninvasive blood glucose sensor that can operate reliably over sustained periods of time has been a much sought after but elusive goal in diabetes management. Since diabetes has no well-established cure, control of elevated glucose levels is critical for avoiding severe secondary health complications in multiple organs including the retina, kidney and vasculature. While fingerstick testing continues to be the mainstay of blood glucose detection, advances in electrochemical sensing-based minimally invasive approaches have opened the door for alternate methods that would considerably improve the quality of life for people with diabetes. In the quest for better sensing approaches, optical technologies have surfaced as attractive candidates as researchers have sought to exploit the endogenous contrast of glucose, notably its absorption, scattering, and polarization properties. Vibrational spectroscopy, especially spontaneous Raman scattering, has exhibited substantial promise due to its exquisite molecular specificity and minimal interference of water in the spectral profiles acquired from the blood-tissue matrix. Yet, it has hitherto been challenging to leverage the Raman scattering signatures of glucose for prediction in all but the most basic studies and under the least demanding conditions. In this Account, we discuss the newly developed array of methodologies that address the key challenges in measuring blood glucose accurately using Raman spectroscopy and unlock new prospects for translation to sustained noninvasive measurements in people with diabetes. Owing to the weak intensity of spontaneous Raman scattering, recent research has focused on enhancement of signals from the blood constituents by designing novel excitation-collection geometries and tissue modulation methods while our attempts have led to the incorporation of nonimaging optical elements. Additionally, invoking mass transfer modeling into chemometric algorithms has not only addressed the physiological lag between the actual blood glucose and the measured interstitial fluid glucose values but also offered a powerful tool for predictive measurements of hypoglycemia. This framework has recently been extended to provide longitudinal tracking of glucose concentration without necessitating extensive a priori concentration information. These findings are advanced by the results of recent glucose tolerance studies in human subjects, which also hint at the need for designing nonlinear calibration models that can account for subject-to-subject variations in skin heterogeneity and hematocrit levels. Together, the emerging evidence underscores the promise of a blood withdrawal-free optical platform-featuring a combination of high-throughput Raman spectroscopic instrumentation and data analysis of subtle variations in spectral expression-for diabetes screening in the clinic and, ultimately, for personalized monitoring.

American Association of Diabetes Educators

MedlinePlus

... Blood Glucose Monitoring Resources Medication Taking Resources Insulin Infusion Set Resources Diabetes and CVD Resources AADE in ... Blood Glucose Monitoring Resources Medication Taking Resources Insulin Infusion Set Resources Diabetes and CVD Resources AADE in ...

Improved post-prandial ghrelin response by nateglinide or acarbose therapy contributes to glucose stability in Type 2 diabetic patients.

PubMed

Zheng, F; Yin, X; Lu, W; Zhou, J; Yuan, H; Li, H

2013-01-01

Recent studies highlight an important role of ghrelin in glucose homeostasis, while the association between ghrelin regulation and glucose fluctuation is unclear. We compared the effects of two postprandial hypoglycemic agents on ghrelin response and determined the contribution of ghrelin response to glucose stability in Type 2 diabetic (T2DM) patients. Forty newly- diagnosed T2DM patients were randomly allocated to receive nateglinide or acarbose for 4 weeks, with twenty body mass index (BMI)-matched normoglycemic subjects as controls. Mean glucose values and daily average glucose excursion were assessed using continuous glucose monitoring system. Serum ghrelin levels were determined by enzyme-linked immunosorbent assay. T2DM patients had similar fasting ghrelin levels (p=0.546), while their postprandial ghrelin suppressions at 30 min and 120 min were reduced as compared to BMI-matched normoglycemic controls (p<0.01). Both nateglinide and acarbose increased post-prandial ghrelin suppression at 120 min and reduced ghrelin area under the curve (AUCGHRL) (p<0.05), while only nateglinide increased postprandial ghrelin suppression at 30 min (p<0.01), which was positively correlated with the increased early-phase insulin secretion by 4 weeks of nateglinide therapy (r=0.48, p=0.05). The decrease in AUCGHRL was positively correlated with the decrease in daily average glucose excursion and mean glucose values either by 4 weeks of nateglinide or acarbose therapy (p<0.05). Both nateglinide and acarbose increase post-prandial ghrelin suppression. Improved ghrelin regulation is most likely to play a role in glucose stability in T2DM patients with nateglinide or acarbose therapy.

Between-monitor differences in step counts are related to body size: implications for objective physical activity measurement.

PubMed

Pomeroy, Jeremy; Brage, Søren; Curtis, Jeffrey M; Swan, Pamela D; Knowler, William C; Franks, Paul W

2011-04-27

The quantification of the relationships between walking and health requires that walking is measured accurately. We correlated different measures of step accumulation to body size, overall physical activity level, and glucose regulation. Participants were 25 men and 25 women American Indians without diabetes (Age: 20-34 years) in Phoenix, Arizona, USA. We assessed steps/day during 7 days of free living, simultaneously with three different monitors (Accusplit-AX120, MTI-ActiGraph, and Dynastream-AMP). We assessed total physical activity during free-living with doubly labeled water combined with resting metabolic rate measured by expired gas indirect calorimetry. Glucose tolerance was determined during an oral glucose tolerance test. Based on observed counts in the laboratory, the AMP was the most accurate device, followed by the MTI and the AX120, respectively. The estimated energy cost of 1000 steps per day was lower in the AX120 than the MTI or AMP. The correlation between AX120-assessed steps/day and waist circumference was significantly higher than the correlation between AMP steps and waist circumference. The difference in steps per day between the AX120 and both the AMP and the MTI were significantly related to waist circumference. Between-monitor differences in step counts influence the observed relationship between walking and obesity-related traits.

Asymptotic tracking and disturbance rejection of the blood glucose regulation system.

PubMed

Ashley, Brandon; Liu, Weijiu

2017-07-01

Type 1 diabetes patients need external insulin to maintain blood glucose within a narrow range from 65 to 108 mg/dl (3.6 to 6.0 mmol/l). A mathematical model for the blood glucose regulation is required for integrating a glucose monitoring system into insulin pump technology to form a closed-loop insulin delivery system on the feedback of the blood glucose, the so-called "artificial pancreas". The objective of this paper is to treat the exogenous glucose from food as a glucose disturbance and then develop a closed-loop feedback and feedforward control system for the blood glucose regulation system subject to the exogenous glucose disturbance. For this, a mathematical model for the glucose disturbance is proposed on the basis of experimental data, and then incorporated into an existing blood glucose regulation model. Because all the eigenvalues of the disturbance model have zero real parts, the center manifold theory is used to establish blood glucose regulator equations. We then use their solutions to synthesize a required feedback and feedforward controller to reject the disturbance and asymptotically track a constant glucose reference of 90  mg/dl. Since the regulator equations are nonlinear partial differential equations and usually impossible to solve analytically, a linear approximation solution is obtained. Our numerical simulations show that, under the linear approximate feedback and feedforward controller, the blood glucose asymptotically tracks its desired level of 90 mg/dl approximately. Copyright © 2017 Elsevier Inc. All rights reserved.

Sensing interstitial glucose to nudge active lifestyles (SIGNAL): feasibility of combining novel self-monitoring technologies for persuasive behaviour change.

PubMed

Whelan, Maxine E; Kingsnorth, Andrew P; Orme, Mark W; Sherar, Lauren B; Esliger, Dale W

2017-10-08

Increasing physical activity (PA) reduces the risk of developing diabetes, highlighting the role of preventive medicine approaches. Changing lifestyle behaviours is difficult and is often predicated on the assumption that individuals are willing to change their lifestyles today to reduce the risk of developing disease years or even decades later. The self-monitoring technologies tested in this study will present PA feedback in real time, parallel with acute physiological data. Presenting the immediate health benefits of being more physically active may help enact change by observing the immediate consequences of that behaviour. The present study aims to assess user engagement with the self-monitoring technologies in individuals at moderate-to-high risk of developing type 2 diabetes. 45 individuals with a moderate-to-high risk, aged ≥40 years old and using a compatible smartphone, will be invited to take part in a 7-week protocol. Following 1 week of baseline measurements, participants will be randomised into one of three groups: group 1- glucose feedback followed by biobehavioural feedback (glucose plus PA); group 2-PA feedback followed by biobehavioural feedback; group 3-biobehavioural feedback. A PA monitor and a flash glucose monitor will be deployed during the intervention. Participants will wear both devices throughout the intervention but blinded to feedback depending on group allocation. The primary outcome is the level of participant engagement and will be assessed by device use and smartphone usage. Feasibility will be assessed by the practicality of the technology and screening for diabetes risk. Semistructured interviews will be conducted to explore participant experiences using the technologies. ISRCTN17545949. Registered on 15/05/2017. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluation of accuracy of ambulatory glucose profile in an outpatient setting in children with type 1 diabetes.

PubMed

Hulse, Anjana; Rai, Suahma; Prasanna Kumar, K M

2016-01-01

In children with type 1 diabetes, intensive diabetes management has been demonstrated to reduce long-term microvascular complications. At present, self-monitoring of blood glucose (SMBG) by patients at home and glycated hemoglobin estimation every 3 months are used to monitor glycemic control in children. Recently, ambulatory glucose profile (AGP) is increasingly being used to study the glycemic patterns in adults. However, accuracy and reliability of AGP in children have not been evaluated yet. To assess the accuracy of AGP data in children with type 1 diabetes mellitus when compared with laboratory random blood sugar (RBS) levels, capillary blood glucose (CBG) measured by glucometer in the hospital, and SMBG monitored at home. Paired RBS, CBG, and AGP data were analyzed for 51 patients who wore AGP sensors for 2 weeks. Simultaneous venous and CBG samples were collected on day 1 and day 14. SMBG at home was checked and recorded by the patients for optimizing insulin doses. Accuracy measures (mean absolute deviation, mean absolute relative difference (MARD), and coefficient of linear regression of AGP on RBS, CBG, and home-monitored SMBG were calculated. Seventy paired RBS, CBG, and AGP data and 362 paired home-monitored SMBG and AGP data were available. The MARD was 9.56% for AGP over RBS and 15.07% for AGP over CBG. The linear regression coefficient of AGP over RBS was 0.93 and that of AGP over CBG was 0.89 ( P < 0.001). The accuracy of AGP over SMBG was evaluated over four ranges: <75, 76-140, 141-200, and >200 mg/dl. In this study, AGP data significantly correlate with RBS and CBG data in children with type 1 diabetes. However, a large number of samples in a research setting would help to document reproducibility of our results.

Cost calculation for a flash glucose monitoring system for UK adults with type 1 diabetes mellitus receiving intensive insulin treatment.

PubMed

Hellmund, Richard; Weitgasser, Raimund; Blissett, Deirdre

2018-04-01

To estimate the costs associated with a flash glucose monitoring system as a replacement for routine self-monitoring of blood glucose (SMBG) in patients with type 1 diabetes mellitus (T1DM) using intensive insulin, from a UK National Health Service (NHS) perspective. The base-case cost calculation was created using the maximum frequency of glucose monitoring recommended by the 2015 National Institute for Health and Care Excellence guidelines (4-10 tests per day). Scenario analyses considered SMBG at the frequency observed in the IMPACT clinical trial (5.6 tests per day) and at the frequency of flash monitoring observed in a real-world analysis (16 tests per day). A further scenario included potential costs associated with severe hypoglycaemia. In the base case, the annual cost per patient using flash monitoring was £234 (19%) lower compared with routine SMBG (10 tests per day). In scenario analyses, the annual cost per patient of flash monitoring compared with 5.6 and 16 SMBG tests per day was £296 higher and £957 lower, respectively. The annual cost of severe hypoglycaemia for flash monitoring users was estimated to be £221 per patient, compared with £428 for routine SMBG users (based on 5.6 tests/day), corresponding to a reduction in costs of £207. The flash monitoring system has a modest impact on glucose monitoring costs for the UK NHS for patients with T1DM using intensive insulin. For people requiring frequent tests, flash monitoring may be cost saving, especially when taking into account potential reductions in the rate of severe hypoglycaemia. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Fabrication of a LRET-based upconverting hybrid nanocomposite for turn-on sensing of H2O2 and glucose

NASA Astrophysics Data System (ADS)

Wu, Shuang; Kong, Xiang-Juan; Cen, Yao; Yuan, Jing; Yu, Ru-Qin; Chu, Xia

2016-04-01

Blood glucose detecting has aroused considerable attention because diabetes mellitus has become a worldwide publish health problem. Herein, we construct an exceptionally simple upconverting hybrid nanocomposite, composed of DNA-templated Ag nanoparticles (DNA-AgNPs) and NaYF4:Yb/Tm@NaYF4 core-shell upconversion nanoparticles (UCNPs), for the sensing of H2O2 and glucose. In this design, UCNPs with bared surface act as the donor, and DNA-AgNPs serve as efficient quenchers. DNA-AgNPs can be directly assembled on the bared surface of UCNPs, which further decreases the distance of donor-to-acceptor. The formation of DNA-AgNPs/UCNP nanocomposite results in luminescence quenching of UCNP by DNA-AgNPs through luminescence resonance energy transfer (LRET). Upon H2O2 addition, AgNPs can be etched and transformed into Ag+, leading to inhibition of the LRET process and causing the recovery of upconversion luminescence. Based on the conversion of glucose into H2O2 by glucose oxidase, the DNA-AgNPs/UCNP nanocomposite can also be exploited for glucose sensing. Moreover, due to the non-autofluorescence offered by UCNPs, the approach developed can be applied to monitor glucose levels in human serum samples with satisfactory results.Blood glucose detecting has aroused considerable attention because diabetes mellitus has become a worldwide publish health problem. Herein, we construct an exceptionally simple upconverting hybrid nanocomposite, composed of DNA-templated Ag nanoparticles (DNA-AgNPs) and NaYF4:Yb/Tm@NaYF4 core-shell upconversion nanoparticles (UCNPs), for the sensing of H2O2 and glucose. In this design, UCNPs with bared surface act as the donor, and DNA-AgNPs serve as efficient quenchers. DNA-AgNPs can be directly assembled on the bared surface of UCNPs, which further decreases the distance of donor-to-acceptor. The formation of DNA-AgNPs/UCNP nanocomposite results in luminescence quenching of UCNP by DNA-AgNPs through luminescence resonance energy transfer (LRET). Upon H2O2 addition, AgNPs can be etched and transformed into Ag+, leading to inhibition of the LRET process and causing the recovery of upconversion luminescence. Based on the conversion of glucose into H2O2 by glucose oxidase, the DNA-AgNPs/UCNP nanocomposite can also be exploited for glucose sensing. Moreover, due to the non-autofluorescence offered by UCNPs, the approach developed can be applied to monitor glucose levels in human serum samples with satisfactory results. Electronic supplementary information (ESI) available: Experimental details and supplementary figures. See DOI: 10.1039/c6nr00470a