Chapter 13 - Androgens and Bone: Clinical Aspects

Abstract

Androgens have myriad actions on the skeleton throughout life. During adolescence those effects clearly promote skeletal growth and the accumulation of mineral mass, and for many years there has been hope that these anabolic effects will be useful in the prevention and therapy of metabolic bone disease in later life. In fact, the essential nature of the effects of androgens in bone remains uncertain, and the clinical usefulness of androgens is clearly defined in only a few situations. Nevertheless, there is an increasing interest in how the actions of androgens are integrated into the broad scheme of bone metabolism and how those effects can be adapted for prevention and therapy. Clinical studies show that androgen therapy provides benefit for the prevention and therapy of bone loss in hypogonadal men, and added gain may result from increases in muscle strength, particularly in older men at risk for falls. Nevertheless, the potential usefulness of androgen therapy, even in men, remains unclear. Major issues to be clarified include the appropriate criteria for patient selection, the specifics of dosing and drug delivery, the nature of short- and long-term adverse effects, and the impact of therapy on fracture rates. Some of these issues can be clarified only with large-scale intervention trials. Androgens may have usefulness in women as well, but adverse effects loom as a more difficult problem. In both men and women, a greater understanding of the molecular mechanisms of androgen action in the skeleton may provide means to harness the beneficial effects of androgens without the disadvantages, for instance by the development of compounds with tissue-specific actions.