Jiang J, Zhang Y, Chen J, Yang X, Mei C, Xiong F, Shi W, Zhou W, Liu X, Sun S, Zhang P, Zhang Y, Zhang Y, Liu S, Zhang Z, Lin Q, Yu Y, Tian J, Luo W, Qin X, Hou FF: Serum and Tissue Levels of Advanced Glycation End Products and Risk of Mortality in Patients on Maintenance Hemodialysis. American Journal of Nephrology DOI 10.1159/000512385
The relationships between tissue and circulating advanced glycan end-products (AGEP) maintained on chronic hemodialysis (HD) for kidney failure are uncertain. Serum levels of AGEP and skin autofluorescence (SAF; as a surrogate for tissue levels of bound AGEP) have been associated with an increased risk of mortality, particularly from cardiovascular disease (CVD), but the findings are inconsistent and meta-analyses have shown significant heterogeneity of outcomes.
Jiang and co-workers sought to clarify these uncertainties in a large (n = 1,634), multicenter, prospective cohort study of prevalent HD patients (median follow-up 5.2 years). N-carboxymethyl-lysine (CML) was measured in serum by spectrophotometry and SAF was assessed non-invasively by a cutaneous auto-fluorescence device. The mean age of the subjects was 57.4 ± 14.6 years with a mean dialysis ± vintage of 50.0 ± 48.4 months.
The baseline SAF positively correlated with all-cause and CVD mortality in a dose-response fashion, but baseline CML levels showed no such effect. Covariates, such as age, serum albumin, and diabetes, did not modify the effect of SAF on mortality. No assessment of glycated albumin or hemoglobin was performed. Adding SAF to the standard mortality risk prediction improved the C-statistic and risk classification, but only modestly. The reliability of the SAF device in individuals with varying skin colors/types was not examined.
These are interesting findings that need confirmation in a more ethnically diverse population. They very likely do not apply to incident HD or to peritoneal dialysis patients.