SAT-128 Evaluating the Accuracy of Glycemic Markers and Risk of Hypoglycemia in Patients with Type 2 Diabetes Mellitus and Chronic Kidney Disease by Continuous Glucose Monitoring

Abstract

Background: Chronic kidney disease (CKD) is a growing global health problem due to the increasing prevalence of Type 2 Diabetes Mellitus (T2DM). Consequently, the management of T2DM becomes challenging with advancing non-dialysis CKD (n-CKD). Prior studies have not confirmed the accuracy of markers such as serum fructosamine (SF) and glycosylated hemoglobin A1c (HbA1c) in this population. Also, there is a paucity of data on the incidence of hypoglycemia in these patients. The present study is twofold; evaluating the accuracy of HbA1c and exploring the frequency and severity of hypoglycemia in T2DM patients with n-CKD by continuous glucose monitoring (CGM). Methods: We studied 80 patients with T2DM and n-CKD defined as eGFR 0-45 ml/min. Patients wore the CGM (Abbott FreeStyle Libre Pro) for up to 14 days, with glucose recorded every 15 minutes, with a maximum of 1,344 glucose measurements. Blood tests were performed in the fasting state at the end of the 14 day CGM. HbA1C and SF were compared by linear regression to patients’ average glucose concentration (AGC) calculated as all of a patient’s CGM glucose results divided by the total number of measurements. Hypoglycemia was defined as plasma glucose below 70 mg/dL. Results: 80 patients wore the CGM for a mean of 12.6±2.8 days. Mean age was 71.3±10.9 years, 77% of patients were men, 12% were black, and mean eGFR 27.0±11.1 ml/min. The mean glucose concentration was 151.4±55.7 mg/dL, mean HbA1C 7.2±1.5% and SF 304.1±57.2 μmol/L. HbA1C significantly correlated with AGC, r=0.82, p<0.0001. The relationship was characterized by the formula, AGC=31.8 x HbA1C - 73.3. There was no significant correlation between serum fructosamine and AGC, r=0.54, p=0.8. 61/80 (76.2%) patients had at least one hypoglycemic episode. The mean number of episodes was 7.4±8.9, with a range of 0-53 episodes. The mean number of minutes of hypoglycemia was 1501±2165. This represents a mean of 7.4±10.1% of total measurement time being hypoglycemic, compared to studies in T2DM without CKD where the number is closer to 1.5%. Conclusion: HbA1C, but not serum fructosamine, was an excellent measure of glycemic control in patients with T2DM and n-CKD. Confirming this with a larger sample size is imperative for disease management. The high burden of hypoglycemia highlights the need to avoid medications that increase risk of hypoglycemia and consider adjusting glycemic targets in this patient population.