Optimal Testosterone Levels Tied to Survival in Older Men
(HealthDay News) – Higher and lower levels of testosterone (T) and its metabolites may raise mortality risk in older men, according to a study published online Nov. 20 in the Journal of Clinical Endocrinology & Metabolism.
Bu B. Yeap, MBBS, PhD, from the University of Western Australia in Perth, and colleagues assessed associations between T and its metabolites dihydrotestosterone (DHT) and estradiol (E2) and all-cause and ischemic heart disease (IHD) mortality in 3,690 community-dwelling men (aged 70–89 years). Early morning samples were collected between 2001 and 2004 and data were linked to deaths through December 2010.
The researchers found that there were 974 deaths (26.4%), including 325 from IHD. Men who died had lower baseline T (12.8 vs. 13.2nmol/L; P=0.013), DHT (1.4 vs. 1.5nmol/L; P=0.002), and E2 (71.6 vs. 74pmol/L; P=0.022). T (quartile [Q]2:Q1: adjusted hazard ratio [HR], 0.82 [P=0.033]; Q3:Q1: HR, 0.78 [P=0.01]; Q4:Q1: HR, 0.86 [P>0.05]) and DHT (Q3:Q1: HR, 0.76 [P=0.003]; Q4:Q1: HR, 0.84 [P>0.05]) were associated with all-cause mortality. There was an association between higher DHT and lower IHD mortality (Q3:Q1: HR, 0.58 [P=0.002]; Q4:Q1: HR, 0.69 [P=0.026]). There were no associations between E2 and either all-cause or IHD mortality.
"Optimal androgen levels are a biomarker for survival because older men with midrange levels of T and DHT had the lowest death rates from any cause, whereas those with higher DHT had lower IHD mortality," the authors write.