Three-year variability in plasma concentrations of the soluble receptor for advanced glycation end products (sRAGE)

Abstract

ObjectivesThe soluble receptor for advanced glycation end products (sRAGE) has been implicated in the development of diabetes-related vascular complications, but the variability of concentrations of sRAGE in the blood is unknown. The objective of this study was to characterize within-person three-year variability of plasma levels of sRAGE. Design and methodsWe measured sRAGE in plasma samples from 179 men and women in the community-based Atherosclerosis Risk in Communities (ARIC) Study at two time points, three years apart. We calculated correlation coefficients and the within-person coefficient of variation (CVw) to characterize variability in sRAGE. We compared these estimates to total cholesterol and white blood cell count (WBC) in the same participants. ResultsMean sRAGE concentrations at the two time points (mean time between measurements=2.9years) were 1096.2pg/mL and 990.2pg/mL, respectively (mean difference=−106.0pg/mL, p-value<0.001). The Pearson's correlation was 0.78 (Spearman's, 0.73). The intra-class correlation coefficient was 0.76 and the CVw was 26.6%. Compared to sRAGE, Pearson's and Spearman's correlations for total cholesterol (0.76 and 0.77) and white blood cell count (0.61 and 0.72) were similar, although CVw for both was lower (8.7% for cholesterol, 15.6% for WBC). Less than 4% of participants' values changed substantially (50% or greater) over the three-year interval. ConclusionsWe observed that sRAGE concentrations remained relatively stable over three years. Our findings suggest that a single measure of circulating sRAGE tracks well in a community-based population and could be a useful measure in clinical and epidemiologic studies of long-term risk.