Accuracy of Continuous Glucose Monitoring in an Insulin-Treated Population Requiring Haemodialysis

Abstract

Background: Continuous glucose monitoring (CGM) is revolutionizing diabetes care by giving both patients and the healthcare professionals unprecedented insights into glucose variability and patterns. It is established in National Institute for Health and Care Excellence (NICE) guidance as a standard of care for type 1 diabetes and diabetes in pregnancy under certain conditions. Diabetes mellitus (DM) is recognized as an important risk factor for chronic kidney disease (CKD). Around a third of patients receiving in-center haemodialysis as renal replacement therapy (RRT) have diabetes, either as a direct cause of renal failure or as an additional co-morbidity. Evidence of poor compliance with the current standard of care (self-monitoring of blood glucose [SMBG]) and overall greater morbidity and mortality, suggests this patient population as an ideal target group for CGM. However, there exists no strong published evidence showing the validity of CGM devices in insulin-treated diabetes patients requiring haemodialysis.

Methods: We applied a Freestyle Libre Pro sensor to 69 insulin-treated diabetes haemodialysis (HD) patients on a dialysis day. Interstitial glucose levels were obtained, and time matched within 7 minutes to capillary blood glucose testing and any plasma blood glucose levels sent. Data cleansing techniques were applied to account for rapidly correcting hypoglycaemia and poor SMBG technique.

Results: Clarke-error grid analysis showed 97.9% of glucose values in an acceptable range of agreement (97.3% on dialysis days and 99.1% on non-dialysis days).

Conclusions: We conclude that the Freestyle Libre sensor is accurate in measuring glucose levels when compared to glucose as measured by capillary SMBG testing and laboratory obtained serum glucose in patients on HD.

Keywords: Libre; continuous glucose monitoring; glucose variability; haemodialysis; self-monitoring of blood glucose.

Figure 1.

Clarke Error Grid for 706 interstitial glucose levels time matched to a blood glucose level. Results indicating 97.9% fall within A and B.

Figure 2.

Clarke Error Grid for dialysis day interstitial glucose levels time matched to a blood glucose level. Results indicating 97.3% fall within A and B on a dialysis day.

Figure 3.

Clark Error Grid for non-dialysis day interstitial glucose levels time matched to a blood glucose level. Results indicating 99.1% fall within A and B on a non-dialysis day.