Testosterone reduces fat and increases muscle mass in non-obese men aged ≥55 years

14 September 2010

Aging is associated with a reduction in testosterone levels in the blood. This reduction causes a number of symptoms, one of which is losing muscle mass.

This small, well-designed 12-month study looked at the effect of the testosterone patch on body composition and hormones in 60 men aged ≥55 years who were healthy and not obese, and who had low-to-normal testosterone levels and typical testosterone deficiency symptoms. Blood testosterone levels increased in patients receiving the testosterone patch and decreased in patients receiving placebo. Fat-free mass and skeletal muscle mass increased in the testosterone group but did not change in the placebo group (Figure). Fat mass decreased with testosterone and increased with placebo; these changes were linked to changes in blood testosterone levels.

The testosterone patch was shown to be safe but one-third of patients left the study early. The main reason for leaving the study was skin irritation.

Testosterone therapy prevents gain in visceral adipose tissue and loss of skeletal muscle in nonobese aging men

Source: Testosterone therapy prevents gain in visceral adipose tissue and loss of skeletal muscle in nonobese aging men. Allan CA, Strauss BJG, Burger HG, Forbes EA, McLachlan RI. J Clin Endocrinol Metab 2008;93(1):139-146.