Effects of Androgens on Bone in Men and Women

Although the beneficial effects of estrogen on bone have been proven in multiple well-designed clinical trials, with respect to testosterone and androgens, the data are less definitive. Testosterone appears to have a role in the development and maintenance of bone mass; however, the mechanism by which androgens exert their effects on bone is still not clearly understood. Despite the increasing use of testosterone supplementation in men and women for the prevention and treatment of osteoporosis, insufficient evidence exists to support the widespread use of these agents for this indication at this time. The data supporting the beneficial effects of testosterone on bone mineral density are more convincing in hypogonadal men than in men with normal testosterone levels, or in women. The transdermal route of administration is often preferred for testosterone therapy because it avoids the first-pass metabolism associated with oral formulations and the pain experienced with intramuscular injections. Other androgens, including anabolic steroids and dihydroepiandrosterone, have also been used. In addition to monitoring for therapeutic response on initiation of androgen therapy, assessment for potential adverse events should be implemented. This should include assessment for adverse effects on the liver and alterations in the lipid profile in both men and women. Men should also be monitored for prostate growth, gynecomastia, priapism, decreased libido, and erythrocytosis, whereas women should be monitored for virilizing effects. Ongoing research into the pathophysiology and clinical effects of testosterone on bone will provide more insights regarding the utility of androgens in these populations.