Association between testosterone levels and the metabolic syndrome in adult men

Objective: To evaluate the relationship between testosterone levels and the metabolic syndrome (MS) in men older than 45 years. Methods: Six hundred and sixty men (45-70 years) selected from 2906 participants of a population screening for prostate cancer were included in this study. Testosterone and the components of MS were assessed in all men. MS was diagnosed according to NCEP-ATP III criteria. Triglycerides (TG)/HDL-cholesterol (chol) index was calculated. Results: The presence of MS was inversely associated with testosterone (chi(2), p < 0.001), independently of age (OR 0.802, CI 95%: 0.724-0.887, p < 0.0001). Hypertension was the most frequent abnormality observed followed by elevated TG and waist circumference (WC). Testosterone correlated positively with HDL-chol (r: 0.14, p < 0.0001) and negatively with body mass index (BMI)(r: -0.29, p < 0.0001), WC (r: -0.26, p < 0.0001), TG (r: -0.20, p < 0.0001), TG/HDL-chol (r: -0.20, p < 0.0001), glucose (r: -0.11, p = 0.005) and MS score (r: -0.23, p < 0.0001). Conclusions: Our results show that in men older than 45 years, as long as testosterone levels decline, the prevalence of MS increases, independently of age. The correlations found between testosterone and four of the five components of MS, as well as with BMI and TG/HDL-chol ratio, a surrogate marker of insulin resistance, suggest considering male hypogonadism as a determinant of developmental abnormalities typical of MS.