Statin therapy and serum testosterone in men with Type 2 diabetes

ABSTRACT

There is a high prevalence of hypogonadism in men with type 2 diabetes. Statins could potentially decrease testosterone levels by reducing the availability of cholesterol for androgen synthesis. In this study we compared testosterone levels and hypogonadal symptoms with statin use in men with type 2 diabetes. Total testosterone, sex hormone-binding globulin [SHBG], and estradiol were measured by an enzyme-linked immunosorbent assay. Bioavailable testosterone was measured by the modified ammonium sulfate precipitation method. Free testosterone was calculated using Vermeulen's formula. Symptoms of hypogonadism were assessed using the Androgen Deficiency in the Aging Male questionnaire. Statins were associated with lower total testosterone and a trend toward lower SHBG compared with untreated patients. Bioavailable testosterone, free testosterone, estradiol, and hypogonadal symptoms were not affected. Atorvastatin was associated with reduced total testosterone and a trend toward reduced SHBG compared with no treatment, and there was a dose-response effect with the lowest levels of total testosterone seen in men treated with >/=20 mg atorvastatin .Simvastatin use was not associated with significant reductions in testosterone or SHBG levels. Assessing androgen status using total testosterone in men with type 2 diabetes treated with Statins, particularly atorvastatin, may potentially lead to diagnostic error. Levels of bioavailable testosterone or free testosterone are recommended for the assessment of hypogonadism in this group if total testosterone levels are borderline