Gonadal Steroids and Body Composition, Strength, and Sexual Function in Men

The latest approaches to diagnosing testosterone deficiency don’t take into account the physiological consequences of different testosterone levels or whether estradiol, testosterone or both are collected for clinical manifestations.

The scientists provided 200 men with good health in the age of 20-50 y.o. with acetate (to suppress endogenous estradiol and testosterone). Some of them, randomly chosen were asked to take in a placebo gel or 2.5 g, 5g, or 10 g of testosterone gel every day for 15 weeks. Another group of men (202 healthy persons) have received testosterone gel or placebo gel, goserelin acetate and anastrozole (in order to suppress testosterone to estradiol conversion). The primary results have been revealed in the percentage of body fat and in lean mass. There were also assessed intraabdominal and subcutaneous fat areas, thigh muscle areas, sexual function and strength.

The results of investigation were the following:

In groups of men who received placebo or 1.25 g or 2.5 g of testosterone per day without anastrozole the percentage of body fat increased. Thigh muscle area and lean mass decreased in men who daily received 1.25 g of testosterone without anastrozole and in those men who received placebo. Leg press strength increased only in the group who was administrated placebo. As the testosterone dose was reduced, the sexual desire declined.

Conclusions made:

It was found out that the necessary amount of testosterone to obtain fat mass, lean mass, sexual function and strength varies from man to man. Androgen deficiency is resulted in decreasing muscle size, lean mass and strength. Whereas deficiency of estrogen results in accumulation of body fat, both contributed to the decline in sexual function.

In the study it was discovered that different symptoms of hypogonadism may develop at different steroid levels. For instance, visceral fat increases even at testosterone level between 300 and 400 ng/dl. But muscle size and strength are unaffected until the level of testosterone is less than 200 ng/dl. That is why the right level of testosterone supplementation for man who is aimed to gain weight and improve abdominal girth will differ from a man whose target is to lose muscle size and strength.

The latest investigations support modifications in the approach to management and evaluation of hypogonadism in men.