Skin Intrinsic Fluorescence Is Associated With Hemoglobin A₁c and Hemoglobin Glycation Index but Not Mean Blood Glucose in Children With Type 1 Diabetes

OBJECTIVE: To evaluate the relationship between skin advanced glycation end products (sAGEs) with mean blood glucose (MBG), hemoglobin A₁c (HbA₁c), and MBG-independent, between-patient differences in HbA₁c among children with type 1 diabetes. RESEARCH DESIGN AND METHODS: Children aged 5 to 20 years with type 1 diabetes of at least 1 year duration participated. At a clinic visit, sAGE was estimated noninvasively by measurement of skin intrinsic fluorescence (SIF). SIF data were adjusted to correct for variation in skin pigmentation. MBG-independent, between-patient differences in HbA₁c were examined by statistically controlling HbA₁c for MBG or alternatively by use of a hemoglobin glycation index (HGI). Results were similar whether HbA₁c, MBG, and HGI were analyzed as single values from the time of the SIF examination visit or as the mean values from all available visits of the patient. RESULTS: HbA₁c was correlated with MBG (r = 0.5; P < 0.001; n = 110). HbA₁c and HGI, but not MBG, were statistically associated with SIF after adjustment for age, duration of diabetes, race, sex, and BMI z-score. SIF increased with age and duration of diabetes and was higher in girls than boys. CONCLUSIONS: sAGE levels estimated by SIF increase with age, duration of diabetes, and female sex. sAGE is correlated with MBG-independent biological variation in HbA₁c, but not with MBG itself. These results suggest that factors besides MBG that influence HbA₁c levels also contribute to accumulation of sAGE.