This article is more than 5 years old. Information may no longer be current.
Dihydrotestosterone linked to incident CVD in elderly men
Click Here to Manage Email Alerts
In a new study, dihydrotestosterone and calculated free dihydrotestosterone were associated with incident cardiovascular disease and all-cause mortality in elderly men, whereas total testosterone and calculated testosterone were not.
Researchers analyzed data for 1,032 men (mean age, 76 years) followed for 9 years as part of the Cardiovascular Health Study, a longitudinal cohort study initiated in 1989. The current study sample consisted of men with no history of prostate cancer or CVD who were examined in 1994. Covariate data collected included age, race, educational level, smoking status, alcohol intake, level of physical activity, weight, height and waist circumference. Total testosterone and dihydrotestosterone were measured in frozen sera from the examinations, and incident CVD and mortality among the men were classified according to the original study’s criteria.
Generalized additive models and penalized regression splines were used to consider the relationship between the hormones and outcomes. Cox proportional hazards regression models were used to estimate the risk for CVD and mortality in relation to total testosterone, dihydrotestosterone, and the calculated free amounts of each. Models were used to adjust for a variety of factors, including age, race, smoking status, hypertension, cholesterol levels and other factors.
Incident CVD and death occurred after a median follow-up of 8.9 and 10.8 years, respectively, according to researchers. Total testosterone and calculated free testosterone were not associated with incident CVD or mortality, whereas dihydrotestosterone and calculated free dihydrotestosterone showed significant curvilinear associations with incident CVD (P=.002 and P=.04) and all-cause mortality (P<.001). Dihydrotestosterone levels <50 ng/dL were inversely associated with the risk for CVD and mortality, but an association with the risk was shown in men with dihydrotestosterone levels >74 ng/dL, according to researchers, who suggest the wide CIs may cause the risk to plateau rather than increase as levels increase.
“[T]he associations found in this study do not establish a causal relationship between [dihydrotestosterone] and adverse outcomes as this cannot be ascertained from an observational study,” the researchers wrote. “Further studies are needed to confirm these results and to clarify the physiologic mechanisms underlying the association of [dihydrotestosterone] with CVD and all-cause mortality.”
Disclosure: One researcher reports receiving research support from Abbott, BHR Pharmaceuticals and GlaxoSmithKline; has an advisory board role at Abbott, Endo, Ligand and Trimel Pharmaceuticals; and is editor for UpToDate.
Click Here to Manage Email Alerts