Temporal reliability of serum soluble and endogenous secretory receptors for advanced glycation end-products (sRAGE and esRAGE) in healthy women

Purpose: The soluble receptor for advanced glycation end-products (sRAGE) and endogenous secretory RAGE (esRAGE) have been considered as biomarkers of several chronic diseases. However, the temporal reliability of their concentrations in the circulation is yet to be demonstrated. We evaluated whether a single measurement of serum sRAGE and esRAGE could serve as an estimate for usual serum levels in epidemiologic studies. Methods: Serum sRAGE and esRAGE were measured using ELISAs in three yearly samples from 36 participants in the New York University Women’s Health Study. The intraclass correlation coefficient (ICC) was used to evaluate temporal reliability. Results: The intra- and inter-batch coefficients of variation were 3.0% and 14.8% for sRAGE and 6.5% and 34.7% for esRAGE, and decreased to 0.4% and 2.1% for sRAGE and 1.0% and 6.3% for esRAGE after log₂-transformation of the data. On the original scale, the ICCs of a single measurement of serum sRAGE and esRAGE were 0.89 (95% CI 0.82–0.94) and 0.87 (95% CI 0.79–0.93), respectively, and were similar using log₂-transformed data. Conclusion: Our results indicate that a single measurement of serum sRAGE and esRAGE is a sufficiently reliable measure of their usual levels that can be used in epidemiologic studies.