Making sense of glucose sensors in end-stage kidney disease: A review

Mean amplitude of glycemic excursion and mortality in critically ill patients: A retrospective analysis using the MIMIC-IV database

BACKGROUND

Glycemic variability (GV) is increasingly recognised as a critical determinant of outcomes in critically ill patients. However, standardised criteria for assessing GV remain undefined.

OBJECTIVE

This study aimed to evaluate the relationship between the Mean Amplitude of Glycemic Excursion (MAGE) and mortality in intensive care unit (ICU) patients, and to determine optimal MAGE thresholds for distinct patient populations.

METHODS

A retrospective cohort of 13 852 critically ill adults with ICU stays exceeding 24 h was analysed. Patients were stratified into MAGE quartiles, and various GV metrics were compared for their predictive performance on mortality. Multivariable-adjusted models were employed to examine associations between MAGE and mortality outcomes.

RESULTS

Patients in higher MAGE quartiles exhibited significantly elevated mortality risks, with the highest quartile associated with ICU mortality (HR 3.59 [95% CI: 2.99-4.31]), in-hospital mortality (HR: 3.43 [95% CI: 2.92-4.02]) and 28-day mortality (HR 2.04 [95% CI: 1.47-2.82]). The relationship between MAGE and mortality was notably stronger in non-diabetic patients (HR: 3.36 [95% CI: 2.90-3.89]) compared to diabetic patients (HR: 1.59 [95% CI: 1.33-1.91]). Restricted cubic spline analyses identified optimal MAGE thresholds of 44.28 mg/dL for the overall population, 58.97 mg/dL for diabetic patients and 17.11 and 37.72 mg/dL for non-diabetic patients. MAGE demonstrated effective predictive performance for all-cause mortality (AUC: 0.6286 [95% CI: 0.6171-0.6400]) compared to other GV metrics. Incorporating MAGE into prognostic models alongside SAPS II and SOFA scores improved performance for all-cause mortality, with net reclassification improvement (NRI) of 0.238 and integrated discrimination improvement (IDI) of 0.008.

CONCLUSION

MAGE exhibits effective predictive value for mortality in ICU patients, with distinct thresholds for diabetic and non-diabetic populations. These findings underscore the importance of tailored GV management strategies in critical care settings and support the adoption of MAGE as a standardised metric for GV assessment in ICU settings.

Consensus Report on the Use of Continuous Glucose Monitoring in Chronic Kidney Disease and Diabetes

This report represents the conclusions of 15 experts in nephrology and endocrinology, based on their knowledge of key studies and evidence in the field, on the role of continuous glucose monitors (CGMs) in patients with diabetes and chronic kidney disease (CKD), including those receiving dialysis. The experts discussed issues related to CGM accuracy, indications, education, clinical outcomes, quality of life, research gaps, and barriers to dissemination. Three main goals of management for patients with CKD and diabetes were identified: (1) greater use of CGMs for better glycemic monitoring and management, (2) further research evaluating the accuracy, feasibility, outcomes, and potential value of CGMs in patients with end-stage kidney disease (ESKD) on hemodialysis, and (3) equitable access to CGM technology for patients with CKD. The experts also developed 15 conclusions regarding the use of CGMs in this population related to CGMs' unique delivery of both real-time information that can guide monitoring and management of glycemia and continuous and predictive data in this population, which is at higher risk for hypoglycemia and hyperglycemia. The group noted three major clinical gaps: (1) CGMs are not routinely prescribed for patients with diabetes and CKD; (2) CGMs are not approved by the United States Food and Drug Administration (FDA) for patients with diabetes who are on dialysis; and (3) CGMs are not routinely available to all of those who need them because of structural barriers in the health care system. These gaps can be improved with greater stakeholder collaboration, education, and awareness brought to the use of CGM technology in CKD.

Research Progress on the Application of CGM in Patients with Diabetes and Hemodialysis

Diabetes mellitus is the main cause of end-stage renal disease (ESKD), and most patients need hemodialysis (HD) treatment after they progress to uremia. Patients with diabetes and HD have obvious blood glucose fluctuation, hyperglycemia and hypoglycemia may both related to the higher mortality. Therefore, maintaining blood glucose stability is the main treatment strategy to improve the prognosis of patients. It is challenging to evaluate the blood glucose control of patients with diabetes and HD. The traditional blood glucose detection methods have certain limitations, they may be affected by many factors in HD patients. The application of continuous glucose monitoring (CGM) system is gradually recognized, CGM can monitor blood glucose real-time, timely, and predictive capabilities, there are fewer factors that are affected blood glucose in HD patients.

Diabetes technology in people with diabetes and advanced chronic kidney disease

Diabetes is the leading cause and a common comorbidity of advanced chronic kidney disease. Glycaemic management in this population is challenging and characterised by frequent excursions of hypoglycaemia and hyperglycaemia. Current glucose monitoring tools, such as HbA1c, fructosamine and glycated albumin, have biases in this population and provide information only on mean glucose exposure. Revolutionary developments in glucose sensing and insulin delivery technology have occurred in the last decade. Newer factory-calibrated continuous glucose monitors provide real-time glucose data, with predictive alarms, allowing improved assessment of glucose excursions and preventive measures, particularly during and between dialysis sessions. Furthermore, integration of continuous glucose monitors and their predictive alerts with automated insulin delivery systems enables insulin administration to be decreased or stopped proactively, leading to improved glycaemic management and diminishing glycaemic fluctuations. While awaiting regulatory approval, emerging studies, expert real-world experience and clinical guidelines support the use of diabetes technology devices in people with diabetes and advanced chronic kidney disease.

Perspective of Continuous Glucose Monitoring-Based Interventions at the Various Stages of Type 2 Diabetes

Continuous glucose monitoring (CGM) is now advocated for the clinical management of individuals with type 1 diabetes (T1D). However, this glucose monitoring strategy is not routinely used in type 2 diabetes (T2D), given the large population, significant cost implications and relatively limited supporting evidence. T2D is a more heterogenous condition compared with T1D with various glucose lowering therapies that do not necessarily require CGM to ensure within target glucose levels. While all individuals with T2D may benefit from CGM at certain time points, the whole T2D population does not necessarily require this technology continuously, which should be prioritized based on patient benefit and cost effectiveness. In this pragmatic opinion piece, we describe the rationale and evidence for CGM use in different subgroups of individuals with T2d, divided according to the stage of the condition, glycemic therapies, presence of diabetes complications, or associated co-morbidities. We discuss a total of 16 T2D subgroups and provide a clinical view on CGM use in each, based on current evidence while also highlighting areas of knowledge gaps. This work provides health care professionals with a simple guide to CGM use in different T2D groups and gives suggestion for future studies to justify expansion of this technology.

Comparison of Point Accuracy Between Two Widely Used Continuous Glucose Monitoring Systems

BACKGROUND

Safe and effective self-management of glucose levels requires immediate access to accurate data. We assessed the point accuracy of the Dexcom G7 Continuous Glucose Monitoring System (Dexcom, Inc., San Diego, CA, USA) and FreeStyle Libre 3 (Abbott Diabetes Care, Alameda, CA, USA) sensors in a head-to-head comparison.

METHOD

Multicenter, single-arm, prospective, nonsignificant risk evaluation enrolled adults (≥ 18 years) with diagnosed type 1 diabetes (T1D) or type 2 diabetes (T2D). Accuracy was assessed by comparing sensor data to laboratory reference values Yellow Springs Instrument [YSI] and capillary blood glucose values. Outcome measures were differences in mean absolute relative difference (MARD), number and percentage of matched glucose pairs within ±20 mg/dL/±20 of reference values within glucose ranges: < 54, 54 to 69, 70 to 180, 181 to 250, > 250 mg/dL, and combined.

RESULTS

Data from 55 adults were included in the analysis. Analysis showed significantly lower MARD with the FreeStyle Libre 3 sensor vs the Dexcom G7 sensor (8.9% vs 13.6%, respectively, P < .0001) with a higher percentage of glucose values within ±20 mg/dL/±20 of reference (91.4% vs 78.6%). The MARD values for both continuous glucose monitoring (CGM) sensors were similar during the first 12 hours; however, the FreeStyle Libre 3 MARD was notably lower than the Dexcom G7 MARD during the next 12 hours (10.0% vs 15.1%, respectively, P < .0001) and throughout the study period.

CONCLUSIONS

The FreeStyle Libre 3 sensor was more accurate than the Dexcom G7 sensor in all metrics evaluated throughout the study period. This is the first head-to-head study to our knowledge that compares the flagship products currently in widespread use of the two largest CGM manufacturers.

Continuous glucose monitoring in people with diabetes and end-stage kidney disease-review of association studies and Evidence-Based discussion

Diabetic nephropathy is currently the leading cause of end-stage kidney disease. The present methods of assessing diabetes control, such as glycated hemoglobin or self-monitoring of blood glucose, have limitations. Over the past decade, the field of continuous glucose monitoring has been greatly improved and expanded. This review examines the use of continuous glucose monitoring in people with end-stage kidney disease treated with hemodialysis (HD), peritoneal dialysis (PD), or kidney transplantation. We assessed the use of both real-time continuous glucose monitoring and flash glucose monitoring technology in terms of hypoglycemia detection, glycemic variability, and efficacy, defined as an improvement in clinical outcomes and diabetes control. Overall, the use of continuous glucose monitoring in individuals with end-stage kidney disease may improve glycemic control and detection of hypoglycemia. However, most of the published studies were observational with no control group. Moreover, not all studies used the same assessment parameters. There are very few studies involving subjects on peritoneal dialysis. The small number of studies with limited numbers of participants, short follow-up period, and small number of manufacturers of continuous glucose monitoring systems are limitations of the review. More studies need to be performed to obtain more reliable results.