Self-administered oral glucose tolerance test with capillary glucose measurements for the screening of diabetes mellitus in high-risk adults: a feasibility study

IntroductionEarly diagnosis of prediabetes based on blood sampling for the oral glucose tolerance test (OGTT) is crucial for intervention but multiple barriers hinder its uptake. This study aimed to assess the feasibility and precision of a self-administered capillary OGTT for type-2 diabetes mellitus (T2DM) in high-risk individuals.Research design and methodsParticipants with history of gestational diabetes or prediabetes were recruited in primary care. Due to their prediabetic status and previous diagnosis of gestational diabetes mellitus, a proportion of participants had previous experience doing OGTT. They self-administered the capillary OGTT and concurrently their venous glucose samples were obtained. They filled a questionnaire to collect their demographic information, views of their capillary OGTT, and their preferred site of the test.ResultsAmong 30 participants enrolled in this feasibility study, 93.3% of them felt confident of performing the capillary OGTT themselves, and 70.0% preferred the test at home. Older, less educated participants found it less acceptable. Mean capillary glucose values were significantly higher than venous glucose values, with mean difference at 0.31 mmol/L (95% CI 0.13 to 0.49) at fasting, and 0.47 mmol/L (95% CI 0.12 to 0.92) 2 hours post-OGTT. Capillary and venous glucose measurements were correlated for fasting (r=0.95; p<0.001) and 2-hour-post-OGTT (r=0.95;p<0.001). The Fleiss-Kappa Score (0.79, p<0.0001) indicated fair agreement between the two methods. The capillary OGTT had excellent sensitivity (94.1%) and negative predictive value (NPV=91.7%) in identifying prediabetes or T2DM status, vis-a-vis to venous glucose samples.ConclusionSelf-administered capillary OGTT is feasible and acceptable, especially among younger adults, with excellent sensitivity and NPV compared with plasma-based OGTT.

Comparison of venous, capillary and interstitial blood glucose data measured during hyperbaric oxygen treatment from patients with diabetes mellitus

Introduction: Patients undergoing hyperbaric oxygen treatments (HBOT) have been shown to experience a reduction in blood glucose (BG) levels during a treatment. This necessitates frequent assessment of BG levels. Continuous glucose monitoring (CGM) may represent an alternative to the current finger prick monitoring method in-chamber, however, continuous sensor glucose (SG) data has not been validated in situ. The aim was to determine the validity of continuous SG and intermittent BG monitoring with serum BG levels in diabetic patients during HBOT. Methods: Measurements were obtained (finger prick [capillary sample], CGM [interstitial fluid], and serum [venous sample]) at baseline, and at 30, 60, 90 and 120 minutes during the hyperbaric treatment. Data were analysed by calculating intraclass correlation coefficients (ICC) and using mixed effects linear regression. Results: The ICC results (n = 10 patients) between the three methods indicated very high and statistically significant absolute agreement at baseline (pre-dive) (ICC = 0.90, 95% CI 0.74-0.97), at 30 minutes (ICC = 0.85, 95% CI 0.61−0.96), 60 minutes (ICC = 0.86, 95% CI 0.58−0.96), 90 minutes (ICC = 0.87, 96% CI 0.63−0.96) and 120 minutes (ICC = 0.90, 95% CI 0.70-0.97). Capillary glucose and CGM SG readings were each within 1 mmol·L-1 on average of the serum glucose reading, with multi-level linear regression finding the average difference between the CGM SG and capillary glucose methods of BG sampling was not statistically significant (P = 0.81). Conclusions: The CGM SG data were comparable with glucose readings from capillary monitoring. Both CGM and capillary data were consistent with serum values.

Estimation of Average Blood Glucose Values Based on Fructosamine Values

Introduction: The fructosamine is originated of the glycation of plasmatic proteins, especially albumin, in addition to immunoglobulins and proteins diverse. It constitutes an alternative biomarker of glycemic control when glycated hemoglobin is not indicated for this purpose. Objective: To define the mathematical relationship between fructosamine and average glucose values. Method: The study comprised the laboratorial data collected of 1227 diabetic subjects (type 1 and type 2). Fructosamine levels obtained at the end of three weeks and measured were compared with the average glucose levels of the three previous weeks. The average glucose levels were determined by the weighted mean of the daily fasting capillary glucose results performed during the study period, and the plasma glucose taken at the time of the fructosamine. Results: A total of 9,450 glucoses were performed. Linear regression analysis between the fructosamine and average glucose levels showed that each increase of 1.0 lower case Greek mumol/L in fructosamine increase 0.5mg/dL in the average glucose levels as evidenced in the equation forward: Average glucose levels = 0.5157 x Fructosamine - 20. According to the coefficient of determination (r2 = 0.353492, P < 0.006881), making it possible to calculate the estimated average glucose according to the frutosamine values. Conclusion: Fructosamine levels can be expressed as average glucose levels for assessing the metabolic control of diabetic patients.

Implantable and transcutaneous continuous glucose monitoring system: a randomized cross over trial comparing accuracy, efficacy and acceptance

Aim To compare accuracy, efficacy and acceptance of implantable and transcutaneous continuous glucose monitoring (CGM) systems. Methods In a randomized crossover trial we compared 12 weeks with Eversense implantable sensor (EVS) and 12 weeks with Dexcom G5 transcutaneous sensor (DG5) in terms of accuracy, evaluated as Mean Absolute Relative Difference (MARD) vs capillary glucose (SMBG), time of CGM use, adverse events, efficacy (as HbA1c, time in range, time above and below range) and psychological outcomes evaluated with Diabetes Treatment Satisfaction Questionnaire (DTSQ), Glucose Monitoring Satisfaction Survey (GMSS), Hypoglycemia Fear Survey (HFS2), Diabetes Distress Scale (DDS). Results 16 subjects (13 males, 48.8 ± 10.1 years, HbA1c 55.8 ± 7.9 mmol/mol, mean ± SD) completed the study. DG5 was used more than EVS [percentage of use 95.7 ± 3.6% vs 93.5 ± 4.3% (p = 0.02)]. MARD was better with EVS (12.2 ± 11.5% vs. 13.1 ± 14.7%, p< 0.001). No differences were found in HbA1c. While using EVS time spent in range increased and time spent in hyperglycemia decreased, but these data were not confirmed by analysis of retrofitted data based on SMBG values. EVS reduced perceived distress, without significant changes in other psychological outcomes. Conclusions CGM features may affect glycemic control and device acceptance.

Evaluation of “Diabetes in Pregnancy Study Group of India” (DIPSI) Criterion as a Diagnostic Test for Gestational Diabetes Mellitus

Introduction: In view of the alarmingly increasing incidence of Gestational Diabetes Mellitus (GDM), worldwide, as well as in India, a consensus to bring about standardization for diagnosis of GDM is needed. Internationally, the WHO 2013 criteria is being widely used, while (Diabetes In Pregnancy Study Group of India) DIPSI non fasting criteria is popularly used in India. There still remains many missed cases of GDM in India, which is a cause of concern. This study was done to compare the DIPSI non fasting, with WHO 2013 criteria for diagnosis of GDM. Methods: this cross-sectional study included 530 pregnant women, attending antenatal clinic of a tertiary care center, of North India, from Feb. 2018 to March 2019 and fulfilling inclusion criteria. All women attending antenatal clinic, during the study period, were subjected to capillary glucose evaluation, 2 hours after 75g oral glucose load, irrespective of the timing of last meal (DIPSI), as part of routine antenatal checkup. After 7 days, only those 530 women, who turned up in fasting state, and fulfilled inclusion criteria, were enrolled in the study and subjected to fasting 75g, oral glucose tolerance test (OGTT) (WHO 2013). Accuracy of DIPSI test was compared, to the fasting WHO 2013 criteria. Capillary glucose was measured using regular, well calibrated, point of care, “Optium Free Style” glucometer. Results: Out of 107 women diagnosed to have GDM by WHO 2013 criteria, only 89 were diagnosed by the DIPSI criteria. DIPSI had a low sensitivity (83.18%) when compared to the WHO 2013 criteria, Conclusion: This study showed that when non fasting DIPSI criteria was used as diagnostic criteria, 10.58% women with GDM, missed the diagnosis. Considering the adverse maternal and perinatal outcome of GDM, implication of missed diagnosis would be grave, especially in a developing country, like India. Hence, use of DIPSI criteria for diagnosing GDM should be reconsidered. Key words: GDM, DIPSI, OGTT, Diabetes in Pregnancy.

Diabetes through transitions in life; from fit to frail

The accelerated ageing that occurs in diabetes results in earlier appearance of the geriatric phenotype, including frailty. Recent guidelines have stressed the need for assessing frailty in the evaluation of older adults living with diabetes. Once evaluated and identified, however, the presence of frailty marks a significant change for the individual. Treatments that have been continued and encouraged often for many years, may be discontinued. Life-prolonging medications such GLP-1 analogues, and SGLT-2 inhibitors are replaced with therapies designed to improve quality of life, reduce glycaemic variability and stabilise the sarcopaenia that characterises frailty, such as insulin. With this, however, comes new problems, such as the risk of hypoglycaemia, the need to for capillary glucose monitoring and sub cutaneous administration. Additionally, new diagnoses that are more common in people in diabetes, such as stroke, heart disease, dementia, falls and fractures will result in further changes, with the need for care and possibly even institutionalisation.

Capillary Triglycerides in Late Pregnancy—Challenging to Measure, Hard to Interpret: A Cohort Study of Practicality

Background: Maternal triglycerides are increasingly recognised as important predictors of infant growth and fat mass. The variability of triglyceride patterns during the day and their relationship to dietary intake in women in late pregnancy have not been explored. This prospective cohort study aimed to examine the utility of monitoring capillary triglycerides in women in late pregnancy. Methods: Twenty-nine women (22 with gestational diabetes (GDM) and 7 without) measured capillary glucose and triglycerides using standard meters at home for four days. On two of those days, they consumed one of two standard isocaloric breakfast meals: a high-fat/low-carbohydrate meal (66% fat) or low fat/high carbohydrate meal (10% fat). Following the standard meals, glucose and triglyceride levels were monitored. Results: Median capillary triglycerides were highly variable between women but did not differ between GDM and normoglycaemic women. There was variability in capillary triglycerides over four days of home monitoring and a difference in incremental area under the curve for capillary triglycerides and glucose between the two standard meals. The high-fat standard meal lowered the incremental area under the curve for capillary glucose (p < 0.0001). Fasting (rho 0.66, p = 0.0002) and postpradial capillary triglycerides measured at home correlated with venous triglyceride levels. Conclusions: The lack of differences in response to dietary fat intake and the correlation between capillary and venous triglycerides suggest that monitoring of capillary triglycerides before and after meals in pregnancy is unlikely to be useful in the routine clinical practice management of women with gestational diabetes mellitus.

Accuracy of Flash Glucose Monitoring in Patients with Diabetes Mellitus on Hemodialysis and Its Relationship with Hydration Status

Background: The use of flash-glucose monitoring system FreeStyle Libre (FSL) has demonstrated benefits in metabolic control and quality of life in different populations with diabetes mellitus (DM), being funded in many countries. Due to this, DM subjects on hemodialysis (HD) are using FSL despite the accuracy in this population being unclear. The aims of the present study are to assess the accuracy of FSL in DM subjects on HD, its relationship to hydration status, and patient satisfaction. Material and Methods: A prospective study in 16 patients with DM in a chronic HD program was conducted. Interstitial glucose values from FSL during a 14-day period were compared to capillary glucose measurements obtained at the same time. Hydration status was measured via bioimpedance spectroscopy. Satisfaction with FSL was obtained from an ad hoc satisfaction questionnaire. Results: A total of 766 paired interstitial and capillary glucose levels were analyzed. A correlation coefficient of 0.936 was determined and a mean absolute relative difference (MARD) value of 23%, increasing to 29% during HD. MARD was not related to hydration status. Interstitial glucose values were lower during HD (100.1 ± 17 mg/dL) than within the 12 hours after (125.1 ± 39 mg/dL; P = .012) and the days without HD (134.2 ± 32 mg/dL; P = .001). Subjects showed high satisfaction with FSL. Conclusion: The accuracy of FSL in DM patients on HD is lower than in other populations, especially during HD sessions and is not related with the hydration status. Despite this, the degree of patient satisfaction with FSL is very high.

Nutritional Bar with Potato-Based Resistant Starch Attenuated Post-Prandial Glucose and Insulin Response in Healthy Adults

Resistant starch is a non-digestible starch fraction and is classified as fiber. Beyond naturally occurring fiber sources, starches can be modified to resist digestion, increase their fiber content and provide physiological benefits. The current study examined acute postprandial glycemic responses of VERSAFIBE™ 1490 resistant starch type-4, containing 90% total dietary fiber (TDF, AOAC (Association of Official Analytical Collaboration International) 991.43 method). In a double-blind, randomized, placebo-controlled, cross-over study, healthy adults (n = 38) consumed a nutritional bar containing either control (2 g), medium (21 g) or high (30 g) fiber. The test bars were matched with control for available carbohydrates, fat and protein. Venous glucose, insulin, and capillary glucose were measured. Mean ± SEM capillary glucose incremental area-under-curve (iAUC0)-120 min in min*mmol/L was lower (p < 0.005) for both fiber bars (136.2 ± 9.2 and 137.0 ± 10.4 for the medium and high fiber bars, respectively) compared to the control bar (174.9 ± 13.5). Mean venous insulin iAUC0-120 min in min*pmol/L was also lower for medium (8096.3 ± 894.5) and high fiber (7533.8 ± 932.9) bars, respectively, compared to the control bar (11871.6 ± 1123.9, p < 0.001). Peak capillary glucose and venous insulin concentrations were also significantly reduced (p < 0.001) after consumption of both fiber bars compared to the control bar. The results of this study suggest that nutritional bars containing potato based RS4 fiber reduced post-consumption glycemic and insulinemic responses when consumed by generally healthy adults.