Comparing Changes in Plasma and Skin Autofluorescence in Low-Flux versus High-Flux Hemodialysis

Abstract

Tissue advanced glycation end products (AGE) are increased in hemodialysis (HD) patients, especially those with cardiovascular complications. Skin autofluorescence (skin-AF) can noninvasively estimate the accumulation of AGE in tissue. The aim was to clarify whether HD using a high-flux (HF) dialyzer favors plasma-or skin-AF removal compared to low-flux (LF) dialysis. 28 patients were treated with either an HF-HD or LF-HD but otherwise unchanged conditions in a cross-over design. A glucose containing dialysate was used. Skin-AF was measured noninvasively with an AGE reader before and after HD. Fluorescence (370 nm/465 nm) of plasma (p-AF) was determined as total and nonprotein-bound fractions. Correction for hemoconcentrations were made using the change in serum albumin.Paired and nonpaired statistical analyses were used. Skin-AF was unchanged after LF- and HF-dialysis. Total, free, and protein- bound p-AF was reduced after a single LF-HD by 21%, 28%, and 17%, respectively (P<.001). After HF HD total and free p-AF was reduced by 5% and 15%, respectively (P<.001), while protein bound values were unchanged. The LF-HD resulted in a more pronounced reduction of p-AF than did HF HD (P<.001). Serum albumin correlated inversely with p-AF in HF-HD. In the dialysis settings used there was no significant change in skin AF after dialysis, with LF or with HF dialysis. Although only limited reduction in plasma fluorescence was observed, this was more pronounced when performing LF dialysis. These data are not in overwhelming support of the use of HF dialysis in the setting used in this study.