180-OR: Glycemic Markers Are Differentially Associated with Cardiovascular Imaging and Outcomes in Long-Duration Type 1 Diabetes

Cardiovascular disease (CVD) is a major cause of mortality in type 1 diabetes (T1D). While glycemic control is related to CVD outcomes in T1D, there is a lack of information on the risk of glycemic excursions and comparative contributions of glycemic markers to CVD in aging populations with T1D. Among the Joslin “Medalists” with T1D≥50 years (n=1043), mean historical HbA1c was obtained across longitudinal visits (median 4.1 years), while a single consecutive 14-day block of continuous glucose monitoring (CGM) data was remotely obtained from a subset of Medalist CGM users (n=110). Additionally, Medalists underwent coronary artery calcification scans (CAC; n=153) and cardiac magnetic resonance imaging of left ventricular (LV) structure and function (CMR; n=111). In the overall cohort, HbA1c was associated with CVD (p0.001). CGM metrics for hyperglycemia (mean glucose, p=0.03; glucose management indicator, p=0.03; and time above range180 mg/dL, p=0.02), but not hypoglycemia or day-to-day glycemic variability, were associated with LV remodeling. Plasma assays for advanced glycation end-products (AGEs; n=200), N-carboxyethyl-lysine (CEL), N-carboxymethyl-lysine (CML), and methylglyoxal-derived hydroimidazolone (MGH1), showed associations with CVD (p=0.04, p=0.04, and p=0.01, respectively); CAC (p=0.05, p=0.01, and p=0.01, respectively); and LV remodeling (p=0.09, p=0.05, and p=0.04, respectively). The association of CEL with CVD replicated in a separate Medalist subset (n=311) with self-reported CVD data (p=0.01). These findings indicated that glycemic parameters assessing long-term, irreversible markers of hyperglycemia (AGEs) are the strongest drivers of CVD in people with long-duration T1D, as compared to hypoglycemia or day-to-day glycemic variability. Our results highlight the need for glycemic control in aging populations with T1D, even after other risk factors like hyperlipidemia and hypertension have been controlled. Disclosure M. Yu: None. S. Jangolla: None. N.A. Ziemniak: None. E.R. Viebranz: None. H. Shah: None. G.L. King: None. Funding American Diabetes Association (9-18-CVD1-005); Mary K. Iacocca FoundationThomas J. Beatson Foundation; National Heart, Lung, and Blood Institute (R01 HL161864-02)