Abstract 9888: Ischemic Heart Disease and Type 2 Diabetes Complications Are Associated with Glycemic Variability Measured by Continuous Glucose Monitoring

Abstract

Introduction: The management of type 2 diabetes mellitus (DM) has focused on achieving normal glucose levels in order to prevent cardiovascular disease (CVD) and other DM-related complications. Some have suggested that glucose variability (GV) may be associated with DM complications. Other studies, using manual glucose testing, failed to prove it. In our retrospective study using a large administrative database and thousands of patients wearing continuous glucose monitors (CGM), we evaluated the association between various glucose parameters and CVD and DM complications. Methods: Of 15,815 people enrolled in a T2DM program who ordered a CGM device, 58.2% actually used it. The final cohort had 4,530 CGM users with > 30 days of CGM data within 90 days. Metrics included mean glucose and GV measures such as SD, IQ range, % coefficient of variation (%CV), mean amplitude of glycemic excursions (MAGE) and time in range. A multivariable regression analysis tested for the association between these metrics and the occurrence of CVD and DM complications based on claims from Jan 2016 through April 2021. Results: The mean age was 53, with a 1:1 gender ratio. Mean glucose level was 157 (SD + 32). At least one CVD condition or DM complication (nephro-, retino-, neuropathy, skin ulcer/gangrene, circulatory problems) was present in 84% of subjects. The 2 most frequent were ischemic heart disease (IHD) in 15.7% and DM kidney disease in 9.5%. Subjects with IHD or DM complications had significantly higher mean glucose and GV measures (p<0.001). However, there was a 10-fold difference between a marker of variability (%CV) and the mean glucose level: for every % point increase in %CV there was a 7% increased likelihood of DM complications, compared with only a 0.7% increase for every additional 1 mg/dl of mean glucose. Conclusions: In a relatively young cohort of persons with T2DM wearing CGM, glycemic variability, as measured by %CV, was more strongly associated with IHD and diabetic complications than mean glucose level. This suggests that management of diabetes should focus more on glycemic variability than absolute glucose levels. Wider adoption of CGM may more effectively detect persons with high glycemic variability at risk for ischemic heart disease and other diabetic complications.