Continuous interstitial glucose monitoring in non-diabetic subjects with end-stage renal disease undergoing maintenance haemodialysis

An updated algorithm for an effective choice of continuous glucose monitoring for people with insulin-treated diabetes

PURPOSE

Continuous Glucose Monitoring (CGM) is a key tool for insulin-treated people with diabetes (PwD). CGM devices include both real-time CGM (rtCGM) and intermittently scanned CGM (isCGM), which are associated with an improvement of glucose control and less hypoglycemia in clinical trials of people with type 1 and type 2 diabetes.

METHODS

This is an expert position to update a previous algorithm on the most suitable choice of CGM for insulin-treated PwD in light of the recent evidence and clinical practice.

RESULTS

We identified six different clinical scenarios, including type 1 diabetes, type 2 diabetes, pregnancy on intensive insulin therapy, regular physical exercise, new onset of diabetes, and frailty. The use of rtCGM or isCGM is suggested, on the basis of the predominant clinical issue, as suboptimal glucose control or disabling hypoglycemia, regardless of baseline HbA1c or individualized HbA1c target.

CONCLUSION

The present algorithm may help to select the best CGM device based on patients' clinical characteristics, needs and clinical context, offering a further opportunity of a "tailored" therapy for people with insulin-treated diabetes.

Expanding the Role of Continuous Glucose Monitoring in Modern Diabetes Care Beyond Type 1 Disease

Application of continuous glucose monitoring (CGM) has moved diabetes care from a reactive to a proactive process, in which a person with diabetes can prevent episodes of hypoglycemia or hyperglycemia, rather than taking action only once low and high glucose are detected. Consequently, CGM devices are now seen as the standard of care for people with type 1 diabetes mellitus (T1DM). Evidence now supports the use of CGM in people with type 2 diabetes mellitus (T2DM) on any treatment regimen, not just for those on insulin therapy. Expanding the application of CGM to include all people with T1DM or T2DM can support effective intensification of therapies to reduce glucose exposure and lower the risk of complications and hospital admissions, which are associated with high healthcare costs. All of this can be achieved while minimizing the risk of hypoglycemia and improving quality of life for people with diabetes. Wider application of CGM can also bring considerable benefits for women with diabetes during pregnancy and their children, as well as providing support for acute care of hospital inpatients who experience the adverse effects of hyperglycemia following admission and surgical procedures, as a consequence of treatment-related insulin resistance or reduced insulin secretion. By tailoring the application of CGM for daily or intermittent use, depending on the patient profile and their needs, one can ensure the cost-effectiveness of CGM in each setting. In this article we discuss the evidence-based benefits of expanding the use of CGM technology to include all people with diabetes, along with a diverse population of people with non-diabetic glycemic dysregulation.

Accuracy of Flash Glucose Monitoring in Hemodialysis Patients With and Without Diabetes Mellitus

AIMS

Glucose and insulin metabolism are altered in hemodialysis patients, and diabetes management is difficult in these patients. We aimed to validate flash glucose monitoring (FGM) in hemodialysis patients with and without diabetes mellitus as an attractive option for glucose monitoring not requiring regular self-punctures.

METHODS

We measured interstitial glucose using a FreeStyle Libre device in eight hemodialysis patients with and seven without diabetes mellitus over 14 days and compared the results to simultaneously performed self-monitoring of capillary blood glucose (SMBG).

RESULTS

In 720 paired measurements, mean flash glucose values were significantly lower than self-measured capillary values (6.17±2.52 vs. 7.15±2.41 mmol/L, p=1.3 E-86). Overall, the mean absolute relative difference was 17.4%, and the mean absolute difference was 1.20 mmol/L. The systematic error was significantly larger in patients without vs. with diabetes (- 1.17 vs. - 0.82 mmol/L) and on dialysis vs. interdialytic days (-1.09 vs. -0.90 mmol/L). Compared to venous blood glucose (72 paired measurements), the systematic error of FGM was even larger (5.89±2.44 mmol/L vs. 7.78±7.25 mmol/L, p=3.74E-22). Several strategies to reduce the systematic error were evaluated, including the addition of +1.0 mmol/L as a correction term to all FGM values, which significantly improved accuracy.

CONCLUSIONS

FGM systematically underestimates blood glucose in hemodialysis patients but, taking this systematic error into account, the system may be useful for glucose monitoring in hemodialysis patients with or without diabetes.

Increase Access, Reduce Disparities: Recommendations for Modifying Medicaid CGM Coverage Eligibility Criteria

Numerous studies have demonstrated the clinical value of continuous glucose monitoring (CGM) in type 1 diabetes (T1D) and type 2 diabetes (T2D) populations. However, the eligibility criteria for CGM coverage required by the Centers for Medicare & Medicaid Services (CMS) ignore the conclusive evidence that supports CGM use in various diabetes populations that are currently deemed ineligible. In an earlier article, we discussed the limitations and inconsistencies of the agency's CGM eligibility criteria relative to current scientific evidence and proposed practice solutions to address this issue and improve the safety and care of Medicare beneficiaries with diabetes. Although Medicaid is administered through CMS, there is no consistent Medicaid policy for CGM coverage in the United States. This article presents a rationale for modifying and standardizing Medicaid CGM coverage eligibility across the United States.

Flash glucose monitoring system in special situations

The management of diabetes mellitus (DM) requires maintaining glycemic control, and patients must keep their blood glucose levels close to the normal range to reduce the risk of microvascular complications and cardiovascular events. While glycated hemoglobin (A1C) is currently the primary measure for glucose management and a key marker for long-term complications, it does not provide information on acute glycemic excursions and overall glycemic variability. These limitations may even be higher in some special situations, thereby compromising A1C accuracy, especially when wider glycemic variability is expected and/or when the glycemic goal is more stringent. To attain adequate glycemic control, continuous glucose monitoring (CGM) is more useful than self-monitoring of blood glucose (SMBG), as it is more convenient and provides a greater amount of data. Flash Glucose Monitoring (isCGM /FGM) is a widely accepted option of CGM for measuring interstitial glucose levels in individuals with DM. However, its application under special conditions, such as pregnancy, patients on hemodialysis, patients with cirrhosis, during hospitalization in the intensive care unit and during physical exercise has not yet been fully validated. This review addresses some of these specific situations in which hypoglycemia should be avoided, or in pregnancy, where strict glycemic control is essential, and the application of isCGM/FGM could alleviate the shortcomings associated with poor glucose control or high glycemic variability, thereby contributing to high-quality care.

The Need to Pair Molecular Monitoring Devices with Molecular Imaging to Personalize Health

By enabling the non-invasive monitoring and quantification of biomolecular processes, molecular imaging has dramatically improved our understanding of disease. In recent years, non-invasive access to the molecular drivers of health versus disease has emboldened the goal of precision health, which draws on concepts borrowed from process monitoring in engineering, wherein hundreds of sensors can be employed to develop a model which can be used to preventatively detect and diagnose problems. In translating this monitoring regime from inanimate machines to human beings, precision health posits that continual and on-the-spot monitoring are the next frontiers in molecular medicine. Early biomarker detection and clinical intervention improves individual outcomes and reduces the societal cost of treating chronic and late-stage diseases. However, in current clinical settings, methods of disease diagnoses and monitoring are typically intermittent, based on imprecise risk factors, or self-administered, making optimization of individual patient outcomes an ongoing challenge. Low-cost molecular monitoring devices capable of on-the-spot biomarker analysis at high frequencies, and even continuously, could alter this paradigm of therapy and disease prevention. When these devices are coupled with molecular imaging, they could work together to enable a complete picture of pathogenesis. To meet this need, an active area of research is the development of sensors capable of point-of-care diagnostic monitoring with an emphasis on clinical utility. However, a myriad of challenges must be met, foremost, an integration of the highly specialized molecular tools developed to understand and monitor the molecular causes of disease with clinically accessible techniques. Functioning on the principle of probe-analyte interactions yielding a transducible signal, probes enabling sensing and imaging significantly overlap in design considerations and targeting moieties, however differing in signal interpretation and readout. Integrating molecular sensors with molecular imaging can provide improved data on the personal biomarkers governing disease progression, furthering our understanding of pathogenesis, and providing a positive feedback loop toward identifying additional biomarkers and therapeutics. Coupling molecular imaging with molecular monitoring devices into the clinical paradigm is a key step toward achieving precision health.

What's Wrong with This Picture? A Critical Review of Current Centers for Medicare & Medicaid Services Coverage Criteria for Continuous Glucose Monitoring

Numerous studies have demonstrated the clinical value of continuous glucose monitoring (CGM) in type 1 diabetes and type 2 diabetes populations. However, the eligibility criteria for CGM coverage required by the Centers for Medicare & Medicaid Services (CMS) ignore conclusive evidence that supports CGM use in various diabetes populations that are currently deemed ineligible. This article discusses the limitations and inconsistencies of the CMS eligibility criteria relative to current scientific evidence and proposes workable solutions to address this issue and improve the safety and care of all individuals with diabetes.

Effects of DPP-4 Inhibitors on Blood Glucose Variability in Japanese Patients with Type 2 Diabetes on Maintenance Hemodialysis: A Prospective Observational Exploratory Study

INTRODUCTION

The precise blood glucose (BG) profile of hemodialysis patients is unclear, as is the effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors in hemodialysis patients with type 2 diabetes. Here, we used continuous glucose monitoring (CGM) to evaluate BG variability in these patients and to assess the efficacy of DPP-4 inhibitors, particularly during hemodialysis sessions and at nighttime (UMIN000012638).

METHODS

We examined BG profiles using CGM in 31 maintenance hemodialysis patients with type 2 diabetes. Differences between patients with and without DPP-4 inhibitors (n = 15 and 16, respectively) were analyzed using a linear mixed-effects model to assess changes in glucose levels in 5-min intervals.

RESULTS

The model revealed that DPP-4 inhibitor use was significantly associated with suppression of a rapid drop in glucose levels, both with and without adjustment for BG levels at the start of hemodialysis. Moreover, the model revealed that the two groups differed significantly in the pattern of changes in BG levels from 0:00 to 6:55 am. DPP-4 inhibitors suppressed the tendency for subsequent nocturnal hypoglycemia.

CONCLUSIONS

This prospective observational exploratory study showed that DPP-4 inhibitors could suppress BG variability during hemodialysis sessions as well as subsequent nocturnal changes in patients with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, UMIN000012638.

Glycemic Monitoring and Management in Advanced Chronic Kidney Disease

Glucose and insulin metabolism in patients with diabetes are profoundly altered by advanced chronic kidney disease (CKD). Risk of hypoglycemia is increased by failure of kidney gluconeogenesis, impaired insulin clearance by the kidney, defective insulin degradation due to uremia, increased erythrocyte glucose uptake during hemodialysis, impaired counterregulatory hormone responses (cortisol, growth hormone), nutritional deprivation, and variability of exposure to oral antihyperglycemic agents and exogenous insulin. Patients with end-stage kidney disease frequently experience wide glycemic excursions, with common occurrences of both hypoglycemia and hyperglycemia. Assessment of glycemia by glycated hemoglobin (HbA1c) is hampered by a variety of CKD-associated conditions that can bias the measure either to the low or high range. Alternative glycemic biomarkers, such as glycated albumin or fructosamine, are not fully validated. Therefore, HbA1c remains the preferred glycemic biomarker despite its limitations. Based on observational data for associations with mortality and risks of hypoglycemia with intensive glycemic control regimens in advanced CKD, an HbA1c range of 7% to 8% appears to be the most favorable. Emerging data on the use of continuous glucose monitoring in this population suggest promise for more precise monitoring and treatment adjustments to permit fine-tuning of glycemic management in patients with diabetes and advanced CKD.

Hypoglycemia in People with Type 2 Diabetes and CKD

BACKGROUND AND OBJECTIVES

Among people with diabetes mellitus, CKD may promote hypoglycemia through altered clearance of glucose-lowering medications, decreased kidney gluconeogenesis, and blunted counter-regulatory response. We conducted a prospective observational study of hypoglycemia among 105 individuals with type 2 diabetes treated with insulin or a sulfonylurea using continuous glucose monitors.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

We enrolled 81 participants with CKD, defined as eGFR<60 ml/min per 1.73 m², and 24 control participants with eGFR≥60 ml/min per 1.73 m² frequency-matched on age, duration of diabetes, hemoglobin A1c, and glucose-lowering medications. Each participant wore a continuous glucose monitor for two 6-day periods. We examined rates of sustained level 1 hypoglycemia (<70 mg/dl) and level 2 hypoglycemia (<54 mg/dl) among participants with CKD. We then tested differences compared with control participants as well as a second control population (n=73) using Poisson and linear regression, adjusting for age, sex, and race.

RESULTS

Over 890 total days of continuous glucose monitoring, participants with CKD were observed to have 255 episodes of level 1 hypoglycemia, of which 68 episodes reached level 2 hypoglycemia. Median rate of hypoglycemic episodes was 5.3 (interquartile range, 0.0-11.7) per 30 days and mean time spent in hypoglycemia was 28 (SD 37) minutes per day. Hemoglobin A1c and the glucose management indicator were the main clinical correlates of time in hypoglycemia (adjusted differences 6 [95% confidence interval, 2 to 10] and 13 [95% confidence interval, 7 to 20] fewer minutes per day per 1% higher hemoglobin A1c or glucose management indicator, respectively). Compared with control populations, participants with CKD were not observed to have significant differences in time in hypoglycemia (adjusted differences 4 [95% confidence interval, -12 to 20] and -12 [95% confidence interval, -29 to 5] minutes per day).

CONCLUSIONS

Among people with type 2 diabetes and moderate to severe CKD, hypoglycemia was common, particularly with tighter glycemic control, but not significantly different from groups with similar clinical characteristics and preserved eGFR.

Hypoglycemia in Hospitalized Hemodialysis Patients With Diabetes: An Observational Study

INTRODUCTION

Hypoglycemia and hyperglycemia affect outcomes in hospitalized patient. Patients with diabetes and end stage renal disease are prone to hypoglycemia and few studies have evaluated glucometrics to identify the incidence and risk factors for hypoglycemia in this population.

METHODS

We designed an observational retrospective review of 150 insulin requiring inpatients with diabetes receiving hemodialysis. We collected demographics, baseline characteristics, and glucometric data focusing on episodes of hypoglycemia with glucose cutoffs <70, <54, and <40 mg/dl. Detailed glucose and insulin data for 24 hours before and after hemodialysis was analyzed for each patient in context of a hypoglycemic episode. T-tests, one-way ANOVA, and chi-square tests were used for statistical analysis.

RESULTS

At least one glucose value less than 70 mg/dl was observed in 51% of hemodialysis patients, less than 54 mg/dl in 28%, and less than 40 mg/dl in 11%. Patients with hypoglycemia had a higher HbA1c, standard deviation of glucose ( P = .0009) and higher total daily dose (TDD) of insulin by weight (0.34 units/kg vs 0.23 units/kg, P = .003). We observed a linear increasing risk for hypoglycemia with increasing TDD, with nearly 65% of hypoglycemic episodes occurring with TDD >0.20 units/kg. A majority (61%) of all hypoglycemic episodes occurred in the 24 hours prior to a hemodialysis session. Type 1 diabetes was independently associated with hypoglycemia.

CONCLUSIONS

Hospitalized diabetes patients undergoing hemodialysis were found to have high rates of hypoglycemia. Our results support using a lower TDD of insulin in this population (<0.23 units/kg/day) and recommend special caution in those with type 1 diabetes.

Changes in gluconeogenesis and intracellular lipid accumulation characterize uremic human hepatocytes ex vivo

It is well known that reduced glomerular filtration rate (GFR) leads to an increased risk of dyslipidemia, insulin resistance, and cardiovascular mortality. The liver is a central organ for metabolism, but its function in the uremic setting is still poorly characterized. We used human primary hepatocytes isolated from livers of nine donors with normal renal function to investigate perturbations in key metabolic pathways following exposure to uremic (n = 8) or healthy (n = 8) sera, and to serum-free control medium. Both uremic and healthy elicited consistent responses from hepatocytes from multiple donors and compared with serum-free control. However, at physiological insulin concentrations, uremic cells accumulated 56% more intracellular lipids. Also, when comparing uremic with healthy medium after culture, it contained more very-low-density lipoprotein-triglyceride and glucose. These changes were accompanied by decreased phosphorylation of AktS473 mRNA levels of key regulators of gluconeogenesis in uremic sera-treated hepatocytes such as phosphoenolpyruvate carboxykinase 1 and glucose 6-phosphate were elevated. We also found increased expression of 11β-hydroxysteroid dehydrogenase mRNA in uremic cells, along with high phosphorylation of downstream p53 and phospholipase C-γ1Y783 Thus our ex vivo data suggest that the uremic hepatocytes rapidly develop a glycogenic and lipogenic condition accompanied by perturbations in a large number of signaling networks.

Effectiveness of continuous glucose monitoring in dialysis patients with diabetes: the DIALYDIAB pilot study

AIMS

The DIALYDIAB trial addresses the contribution of iterative sequences of continuous glucose monitoring (CGM) on glucose control in dialysis patients with diabetes.

MATERIALS AND METHODS

In this before-after monocentric 12-week pilot study, dialysis patients with diabetes were monitored with self-monitoring blood glucose (SMBG) 3 times per day during a 6-week period followed by a 5-day CGM recording at 2-week interval during another 6-week period. SMBG and CGM profiles were remotely analyzed by a single diabetes expert who gave therapeutic counseling to dialysis physicians.

RESULTS

Fifteen patients who entered the study had a male/female ratio 8/7, age 60.9±14.8 years, BMI 29.9±7.8, diabetes duration 19.2±8.5 years and dialysis duration 6.5±6.9 years. Treatments were diet alone (20%) or diet plus insulin (80%). Mean CGM glucose level was 8.3±2.5 mmol/l at baseline (T0), 8.2±1.6 mmol/l at the end of the SMBG period (T1) (ns) and 7.7±1.6 mmol/l at the end of the CGM period (T2) (p<0.05 vs. T0). Glucose AUC>10 mmol/l was 0.9±1.4 mmol/l/day at T0 and decreased to 0.4±0.5 at T2 (p<0.05)) without change in glucose AUC<3.3 mmol/l. Treatment adaptation was higher during the CGM period (1.4±1.0 and 2.1±0.9 treatment change at T1 and T2, respectively; p<0.05).

CONCLUSIONS

In patients with diabetes on chronic dialysis, iterative CGM monitoring was associated with more frequent treatment changes and finally, better glucose control, without increased risk of hypoglycemia.

Nanobiotechnology advanced antifouling surfaces for the continuous electrochemical monitoring of glucose in whole blood using a lab-on-a-chip

In the current work we have developed a lab-on-a-chip containing embedded amperometric sensors in four microreactors that can be addressed individually and that are coated with crystalline surface protein monolayers to provide a continuous, stable, reliable and accurate detection of blood glucose. It is envisioned that the microfluidic device will be used in a feedback loop mechanism to assess natural variations in blood glucose levels during hemodialysis to allow the individual adjustment of glucose. Reliable and accurate detection of blood glucose is accomplished by simultaneously performing (a) blood glucose measurements, (b) autocalibration routines, (c) mediator-interferences detection, and (d) background subtractions. The electrochemical detection of blood glucose variations in the absence of electrode fouling events is performed by integrating crystalline surface layer proteins (S-layer) that function as an efficient antifouling coating, a highly-oriented immobilization matrix for biomolecules and an effective molecular sieve with pore sizes of 4 to 5 nm. We demonstrate that the S-layer protein SbpA (from Lysinibacillus sphaericus CCM 2177) readily forms monomolecular lattice structures at the various microchip surfaces (e.g. glass, PDMS, platinum and gold) within 60 min, eliminating unspecific adsorption events in the presence of human serum albumin, human plasma and freshly-drawn blood samples. The highly isoporous SbpA-coating allows undisturbed diffusion of the mediator between the electrode surface, thus enabling bioelectrochemical measurements of glucose concentrations between 500 μM to 50 mM (calibration slope δI/δc of 8.7 nA mM(-1)). Final proof-of-concept implementing the four microfluidic microreactor design is demonstrated using freshly drawn blood. Accurate and drift-free assessment of blood glucose concentrations (6. 4 mM) is accomplished over 130 min at 37 °C using immobilized enzyme glucose oxidase by calculating the difference between autocalibration (10 mM glc) and background measurements. The novel combination of biologically-derived nanostructured surfaces with microchip technology constitutes a powerful new tool for multiplexed analysis of complex samples.