Study reveals link between atorvastatin treatment and lower total testosterone in type 2 diabetics.
TORONTO—Atorvastatin use may lower total testosterone and sex-hormone binding globulin (SHBG) in men with type 2 diabetes, a British study suggests. The statin had no effect on bioavailable or free testosterone.
“This is really an important thing to keep in mind in terms of diagnosis,” said study investigator Roger Stanworth, MD, clinical research registrar in the Department of Diabetes, Endocrinology & Metabolism at the University of Sheffield in South Yorkshire. Clinicians could overdiagnose hypogonadism if they rely on measurements of total testosterone. Consequently, they should measure bioavailable testosterone instead, he observed.
Steroid hormones and androgens are produced from cholesterol, and it has been theorized that statin treatment could decrease testosterone levels by reducing the availability of cholesterol, he noted. Previous studies have not found significant effects of statins on serum testosterone levels but the studies often have been short in duration or had a limited sample size.
Men with type 2 diabetes have a high prevalence of low testosterone levels, and testosterone replacement therapy for hypogonadal men with type 2 diabetes improves insulin sensitivity and glycemic control.
The study compared androgen status with statin use in a group of 355 Caucasian men with type 2 diabetes (mean age 58 years). A total of 168 men were treated with statins (primarily simvastatin and atorvastatin) and 187 men were untreated. The treated and untreated men did not differ significantly with respect to glycemic control, BP, or obesity.
Statin use was associated with lower total testosterone levels (340 vs. 384 ng/dL) and SHBG levels (839 vs. 1,008 ng/dL) but bioavailable and calculated free testosterone were not significantly reduced. The ADAM hypogonadal symptom score was not affected. Atorvastatin, but not simvastatin, was associated with reduced total testosterone (326 vs. 384 ng/dL) and SHBG (787 vs. 1,008 ng/dL) compared with no treatment.
The researchers observed a dose-response effect, with the lowest levels of testosterone occurring in men treated with 20 mg or more of atorvastatin. Simvastatin did not cause a significant reduction in testosterone or SHBG levels.
Study findings were presented here at the 89th annual meeting of The Endocrine Society.