Selenium Concentrations and Mortality among Community-Dwelling Older Adults: Results from IlSIRENTE Study

Abstract

Background: Selenium has a wide range of pleiotropic effects, influencing redox homeostasis, thyroid hormone metabolism, and protecting from oxidative stress and inflammation. Serum selenium levels are reduced in the older population.

Objectives: to investigate the association of serum selenium levels with all-cause mortality in a sample of community-dwelling older adults.

Design and setting: Data are from the 'Invecchiamento e Longevità nel Sirente' (Aging and Longevity in the Sirente geographic area, ilSIRENTE) study, a prospective cohort study that collected information on individuals aged 80 years and older living in an Italian mountain community (n=347). The main outcome was risk of death after ten years of follow-up.

Participants and measurements: Participants were classified according to the median value of selenium (105.3 μg/L) in two groups: high selenium and low selenium.

Results: A total of 248 deaths occurred during a 10-year follow-up. In the unadjusted model, low levels of selenium was associated with increased mortality (HR, 0.66; 95% CI 0.51-0.85). After adjusting for potential confounders the relationship remained significant (HR, 0.71; 95% CI 0.54-0.92).

Conclusions: Low serum levels of selenium are associated with reduced survival in elderly, independently of age and other clinical and functional variables.

Keywords: Selenium; frail elderly; mortality.