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

Abstract

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.