Glycation and Glucose Variability in Subjects with Type 1 Diabetes

High glucose variability (GV) and increased glycation may play a role in the development of diabetes complications. We aimed to assess associations between serum levels of glycation markers and GV metrics in people with type 1 diabetes (T1D). This study included 128 adult patients with T1D and 30 normoglycemic individuals as control. Time in ranges (TIRs), coefficient of variation (CV), mean amplitude of glycemic excursions (MAGE), and mean absolute glucose changes (MAG) were derived from continuous glucose monitoring. Serum glycated albumin (GA), pentosidine, advanced glycation end-products (AGEs), and soluble receptor for advanced glycation end products (sRAGE) were assessed by ELISA. Serum concentrations of GA, pentosidine, and AGEs were increased in patients when compared to control, sRAGE showed no difference. The levels of pentosidine and AGEs were significantly higher in patients with non-targeted TIR than in those with TIR >70%. The concentrations of AGEs were also higher in those with CV ≥ 36%. In patients with diabetes, all glycation products correlated positively with mean glucose, time above range, and MAGE; pentosidine and AGEs correlated negatively with TIR and positively with MAG. Serum GA and pentosidine demonstrated positive correlations with CV. In multivariate stepwise regression analysis, HbA1c, estimated glomerular filtration rate, and CV were associated with GA, while HbA1c was predictor for AGEs. The results suggest that GV may contribute to increased glycation, at least at the early stages, in people with T1D.