The Fast-Glycator Phenotype, Skin Advanced Glycation End Products, and Complication Burden Among People With Type 1 Diabetes

Abstract

OBJECTIVE Existence of a fast-glycator phenotype among people with type 1 diabetes (T1D) is debated. Routine use of glucose sensors allows the comparison of long-term average glucose levels with laboratory HbA1c values. We herein evaluated whether participants with T1D and HbA1c values higher than their glucose management indicator (GMI) had greater accumulation of advanced glycation end products (AGEs) and chronic complications. RESEARCH DESIGN AND METHODS We included participants with T1D using the intermittently scanned continuous glucose monitoring system consecutively for at least 90 days and having a labora-tory-determined HbA1c at the end of observation. Skin AGEs were estimated using the skin autofluorescence (SAF) method. The complication burden was assessed by a standardized screening. The fast-glycator phenotype was defined as having a GMI to HbA1c ratio <0.9. RESULTS We included 135 individuals with T1D (58% men; mean age, 44.4 years) with a mean diabetes duration of 21 years and a mean HbA1c value of 7.7%. Thirty (22.2%) were defined as having the fast-glycator phenotype. As expected, fast glycators had higher HbA1c (8.6% vs. 7.5%; P < 0.001) with similar 90-day mean glucose level (172 vs. 168 mg/dL; P = 0.52). Fast glycators had higher SAF than did other participants (2.5 vs. 2.1 arbitrary units; P = 0.005) and had a significantly higher prevalence of dyslipide-mia (73% vs. 44%; P = 0.005), macroangiopathy (38% vs. 9%; P = 0.001), albuminuria (25% vs. 7%; P = 0.038), and retinopathy (61% vs. 38%; P = 0.022). After adjusting for age and dyslipidemia, the fast-glycator phenotype remained significantly associated with macroangiopathy (odds ratio 3.72; 95% CI 1.22–11.4). CONCLUSIONS In T1D, a fast-glycator phenotype defined by the GMI to HbA1c ratio is character-ized by elevated skin AGEs and is associated with the complication burden.