Men experiencing a pronounced, age-related decline in testosterone level are more likely to die of any cause during a 15-year period vs. men who have testosterone levels in the 10th to 90th percentile, according to findings reported in the European Journal of Endocrinology.
Stine A. Holmboe, MSc, a doctoral student in the department of growth and reproduction at the University of Copenhagen, Denmark, and colleagues analyzed data from 1,167 men aged 30 to 60 years participating in the Danish Monitoring Trends and Determinants of Cardiovascular Disease (MONICA1) study, conducted between November 1982 and February 1984, as well as the follow-up examination 10 years later (MONICA10), conducted between 1993 and 1994. Researchers measured levels of testosterone, sex hormone-binding globulin and luteinizing hormone at baseline and follow-up, and then followed the cohort for up to 18 years (mean, 15.2 years) using data from national mortality registries. Researchers used Cox proportional hazard models, with age as the underlying time scale, to assess the association between intra-individual hormone changes and all-cause, CVD and cancer mortality.
During follow-up, 421 men (36.1%) died (106 cancer-related deaths; 119 CVD-related deaths). The estimated mean intra-individual percentage change in hormone levels per year for the cohort were –1.5% for total testosterone, 0.9% for SHBG, –1.9% for free testosterone and 1% for luteinizing hormone. When estimated cross-sectionally, however, mean percentage changes in hormone levels per year were –0.4% for total testosterone, 1.2% for SHBG, –1.1% for free testosterone and 1.1% for luteinizing hormone, according to researchers.
Researchers observed that men who experienced the most pronounced decline in total testosterone — men in the lowest 10th percentile — saw the greatest increased risk for all-cause mortality (HR = 1.6; 95% CI, 1.08-2.38) vs. the reference category. The risk corresponded with an annual total testosterone decline of at least –0.6 nmol/L.
Across tertiles of SHBG levels, researchers found no significant differences in all-cause mortality; however, there was a U-shaped trend observed, with increases in all-cause mortality for those with a change in SHBG levels below the 10th percentile (< –0.7 nmol/L per year) or above the 90th percentile (> 1.1 nmol/L per year) vs. the middle group.
Men with the most pronounced decline in free testosterone also saw an increased risk for all-cause mortality; however, this was significant only in the tertile model (HR = 1.45; 95% CI, 1.09-1.92), according to researchers. There were no disease-specific associations observed, and associations were independent of age, baseline hormone levels and lifestyle factors.
“A possible causal link between an increased tempo in age-related [testosterone] decline and subsequent health is unknown and remains to be investigated,” the researchers wrote. – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.