Low free testosterone level as a predictor of cardiovascular events in Japanese men with coronary risk factors

Abstract

ABSTRACT Introduction Late-onset hypogonadism is associated with higher mortality largely due to cardiovascular disease (CVD). Objective We investigated whether a low plasma free testosterone (FT) level could predict cardiovascular events in middle-aged Japanese men with coronary risk factors. Methods We reviewed retrospectively our institutional database of patients with any coronary risk factor (hypertension, diabetes, dyslipidemia, smoking, and obesity) without a previous history of CVD. Serum early morning free testosterone (FT) levels, collected at baseline, were analyzed. Patient age, baseline FT level, and the above coronary risk factor were selected as potential predictors of cardiovascular events. Multivariable time-to-event analysis (Cox proportional hazards), and Kaplan-Meier curve were performed to define impact of the FT level on time of cardiovascular (CV) events. Results Four hundred and sixty-six male outpatients (37–89 years old, mean ± SD = 65.1 ± 10.5 years) who had any coronary risk without a previous history of CVD were accumulated. During the mean follow-up period of 84.8 months, a total of 126 CV events occurred. Kaplan–Meier survival analysis by tertile of plasma FT levels revealed that the subjects with the lowest FT tertiles (<6.5 pg/ml) were more likely to develop CV events than those with the highest tertiles (>9.3 pg/ml) (P<0.01 by log-rank test). In multivariate analysis, the subjects with the highest tertiles of plasma FT (>9.3 pg/ml) and those with the second tertiles of plasma FT (6.6–9.2 pg/ml) had significantly lower CV event risk compared to those with the lowest FT tertiles (<6.5 pg/ml) (HR, 0.524; 95% CI, 0.309–0.887, P=0.016 and HR, 0.617; 95% CI, 0.389-0.976, P=0.030, respectively). Furthermore, age, hypertension, duration of diabetes, dyslipedemia and current smoking showed independently significant association with CV events. Conclusion In middle-aged Japanese men with some coronary risk factors, lower FT is a predictor for the development of CVDs, independently on any coronary risk factors and age. Disclosure Work supported by industry: no.