Sex-specific associations of serum selenium and selenoprotein P with type 2 diabetes mellitus and hypertension in the Berlin Aging Study II

BACKGROUND: Selenium is essential for expression and proper function of a set of redox active selenoproteins implicated in aging-relevant diseases, e.g. type 2 diabetes mellitus (T2D) and hypertension. However, data in cohorts of older adults, particularly with respect to different Se biomarkers and sex-specific analyses are sparse. OBJECTIVE: To assess associations of serum Se and selenoprotein P (SELENOP) concentrations with T2D and hypertension in a cohort of older females and males. METHODS: This study included 1500 participants from the Berlin Aging Study II. Diagnosis of T2D was made in case of antidiabetic medication, self-reported T2D, or laboratory parameters. Diagnosis of hypertension was based on self-report, blood pressure measurement, or anti-hypertensive medication. Se was measured by spectroscopy, and SELENOP by ELISA. Multiple adjusted regression models quantified dose-dependent associations. RESULTS: Participants had a median(IQR) age of 68 (65,71) years, and 767 (51%) were women. 191 (13%) participants had T2D and 1126 (75%) had hypertension. Se and SELENOP correlated significantly (r = 0.59, p < 0.001), and were elevated in those with self-reported Se supplementation. Serum Se and SELENOP were not associated with T2D in the whole cohort. In men, SELENOP was positively associated with T2D, OR (95%CI) for one mg/L increase in SELENOP was 1.22 (1.00,1.48). Se was non-linearly associated with hypertension, comparing to the lowest quartile (Q1), and participants with higher Se levels (Q3) had a lower OR (95%CI) of 0.66 (0.45,0.96), which was specific for men. SELENOP positively associated with hypertension, and OR (95%CI) per one mg/L increase was 1.15 (1.01,1.32). CONCLUSIONS: The data suggest a sex-specific interrelationship of Se status with T2D and hypertension, with apparent biomarker-specific associations.