Factors Associated With Change in Skin Autofluorescence, a Measure of Advanced Glycation End Products, in Persons Receiving Dialysis

INTRODUCTION: An increase over time in skin autofluorescence (SAF), a measure of accumulation of advanced glycation end products (AGE), predicts higher mortality on hemodialysis (HD). However, evidence is lacking regarding factors that contribute to changes in SAF over time in populations on dialysis. We investigated the rate of change in SAF over 1 year and the factors associated with these changes. METHODS: We enrolled 109 patients on HD and 28 on peritoneal dialysis in a prospective study. SAF was measured at baseline, 3, 6, 9, and 12 months. Rate of change in SAF was calculated using the SLOPE function in Microsoft Excel (Microsoft, Redmond, WA). Participants were then grouped into those with stable SAF or increasing SAF. Dietary AGE intake and nutritional assessments were performed at baseline, 6, and 12 months. RESULTS: The mean SAF trend observed was an increase of 0.30 ± 0.63 arbitrary units (AU) per year, but this varied from a decrease of 0.15 ± 0.44 to an increase of 0.76 ± 0.42 AU per year in stable and increasing SAF groups, respectively. Increasing SAF was more common in participants who developed malnutrition during the observation period, whereas those who became well-nourished were more likely to have stable SAF (8 [80%] vs. 14 [42%]; P = 0.02). Development/prevalence of malnutrition over 1 year, HD as first dialysis modality, and current smoking were independent predictors of increasing SAF. CONCLUSION: SAF increases over time in most persons on dialysis. Independent determinants of increasing SAF were development/prevalence of malnutrition, HD as first dialysis modality, and current smoking. Strategies to reduce/prevent the rise in SAF, including prevention/correction of malnutrition, should be investigated in prospective studies.