Hemoglobin glycation index among adults with type 1 diabetes: Association with double diabetes features.

Background: The hemoglobin glycation index (HGI) represents the discrepancy between the glucose management indicator (GMI) based on mean blood glucose levels and laboratory values of glycated hemoglobin (HbA1c). The HGI is a promising indicator for identifying individuals with excessive glycosylation, facilitating personalized evaluation and prediction of diabetic complications. However, the factors influencing the HGI in patients with type 1 diabetes (T1D) remain unclear. Autoimmune destruction of pancreatic β cells is central in T1D pathogenesis, yet insulin resistance can also be a feature of patients with T1D and their coexistence is called "double diabetes" (DD). However, knowledge regarding the relationship between DD features and the HGI in T1D is limited.

Aim: To assess the association between the HGI and DD features in adults with T1D.

Methods: A total of 83 patients with T1D were recruited for this cross-sectional study. Laboratory HbA1c and GMI from continuous glucose monitoring data were collected to calculate the HGI. DD features included a family history of type 2 diabetes, overweight/obesity/central adiposity, hypertension, atherogenic dyslipidemia, an abnormal percentage of body fat (PBF) and/or visceral fat area (VFA) and decreased estimated insulin sensitivity. Skin autofluorescence of advanced glycation end products (SAF-AGEs), diabetic complications, and DD features were assessed, and their association with the HGI was analyzed.

Results: A discrepancy was observed between HbA1c and GMI among patients with T1D and DD. A higher HGI was associated with an increased number of SAF-AGEs and a higher prevalence of diabetic microangiopathy (P = 0.030), particularly retinopathy (P = 0.031). Patients with three or more DD features exhibited an eight-fold increased risk of having a high HGI, compared with those without DD features (adjusted odds ratio = 8.12; 95% confidence interval: 1.52-43.47). Specifically, an elevated PBF and/or VFA and decreased estimated insulin sensitivity were associated with high HGI. Regression analysis identified estimated insulin sensitivity and VFA as factors independently associated with HGI.

Conclusion: In patients with T1D, DD features are associated with a higher HGI, which represents a trend toward excessive glycosylation and is associated with a higher prevalence of chronic diabetic complications.