Testosterone concentrations and risk of cardiovascular events in androgen-deficient men with atherosclerotic cardiovascular disease.

ABSTRACT

BACKGROUND: Whether androgen deficiency among men increases the risk of cardiovascular (CV) events or is merely a disease marker remains a subject of intense scientific interest. OBJECTIVES: Among male subjects in the AIM-HIGH Trial with metabolic syndrome and low baseline levels of high-density lipoprotein (HDL)-cholesterol who were randomized to niacin or placebo plus simvastatin, we examined the relationship between low baseline testosterone (T) concentrations and subsequent CV outcomes during a mean 3-year follow-up. METHODS: In this post hoc analysis of men with available baseline plasma T concentrations, we examined the relationship between clinical/demographic characteristics and T concentrations both as a continuous and dichotomous variable (<300 ng/dL ["low T"] vs. ≥300 ng/dL ["normal T"]) on rates of pre-specified CV outcomes, using Cox proportional hazards models. RESULTS: Among 2118 male participants in whom T concentrations were measured, 643 (30%) had low T and 1475 had normal T concentrations at baseline. The low T group had higher rates of diabetes mellitus, hypertension, elevated body mass index, metabolic syndrome, higher blood glucose, hemoglobin A1c, and triglyceride levels, but lower levels of both low-density lipoprotein and HDL-cholesterol, and a lower rate of prior myocardial infarction (MI). Men with low T had a higher risk of the primary composite outcome of coronary heart disease (CHD) death, MI, stroke, hospitalization for acute coronary syndrome, or coronary or cerebral revascularization (20.1%) compared with the normal T group (15.2%); final adjusted HR 1.23, P = .07, and a higher risk of the CHD death, MI, and stroke composite endpoint (11.8% vs. 8.2%; final adjusted HR 1.37, P = .04), respectively. CONCLUSIONS: In this post hoc analysis, there was an association between low baseline testosterone concentrations and increased risk of subsequent CV events in androgen-deficient men with established CV disease and metabolic syndrome, particularly for the composite secondary endpoint of CHD death, MI, and stroke. CONDENSED ABSTRACT In this AIM-HIGH Trial post hoc analysis of 2118 men with metabolic syndrome and low HDL-cholesterol with available baseline plasma testosterone (T) samples, 643 males (30%) had low T (mean 229 ng/dL) and 1475 (70%) had normal T (mean 444 ng/dL) concentrations. The "low T" group had a 24% higher risk of the primary 5-component endpoint (20.1%) compared with the normal T group (15.2%); final adjusted HR 1.23, P = .07). There was also a 31% higher risk of the secondary composite endpoint coronary heart disease death, myocardial infarction, and stroke (11.8% vs. 8.2%, final adjusted HR 1.37, P = .04) in the low vs. normal T group, respectively.