Selenium and All-cause Mortality in End-Stage Renal Disease. Retrospective Observational Cohort Study

The objectives of the study were to determine whether low plasma selenium levels (<63 μg/L according to population-based reference interval) were associated with poorer survival among adult patients with end-stage renal disease (ESRD) on dialysis treatment and to study whether plasma selenium behaved as a biomarker of mortality risk independent of other monitored biochemical markers.

This is a retrospective observational cohort study that included 85 patients with ESRD on 3 modalities of dialysis, with a plasma selenium test performed 5-6 years before the study.

Patients with low selenium showed an increased risk of all-cause mortality (hazard ratio = 2.952, 95% CI 1.402-6.217) compared with patients with normal or high selenium (>118 μg/L), according to a Cox multivariate model that included age and history of cardiovascular disease as covariates. Patients with low selenium had an increased risk of all-cause mortality (hazard ratio = 2.894, 95% CI 1.457-5.751) according to a model that included age, anemia, and low albumin as covariates. Low albumin patients had an increased risk of having low plasma selenium (odds ratio = 5.778, 95% CI 2.212-15.098).

Low plasma selenium group's survival was significantly lower than that of the group with normoselenemia or hyperselenemia. Plasma selenium behaved as a biomarker of mortality risk independent of other biochemical markers usually monitored in patients with ESRD.