Male osteoporosis: new trends in diagnosis and therapy

Abstract

Osteoporosis is a common condition in men affecting approximately 2 million males in the US. Compared with women, osteoporosis develops later in life and the incidence of osteoporosis-related fractures is lower in men. The morbidity and mortality associated with osteoporotic fractures are much greater in men compared with women, and secondary causes of osteoporosis are more frequently (in approximately 50% of cases) identified in men compared with women with osteoporosis. Excessive alcohol consumption, glucocorticoid excess and hypogonadism are the most commonly identified causes. Primary osteoporosis in men has been linked to changes in sex steroid secretion, the growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis and the vitamin D-parathyroid hormone (PTH) 25-hydroxyvitamin D [25(OH)D]-PTH system. Diagnosing osteoporosis in men is complicated by an ongoing debate on whether to use sex-specific reference values for bone mineral density (BMD) or female reference values. The International Society for Clinical Densitometry recommended using a T score of -2.5 or less of male reference values to diagnose osteoporosis in men who are > or =65 years of age. However, this definition is yet to be validated in terms of fracture incidence and prevalence. Ensuring adequate calcium and vitamin D intake is the cornerstone of any regimen aimed at preventing or treating osteoporosis in men. Bisphosphonates are currently the therapy of choice for treatment of male osteoporosis. A short course of parathyroid hormone (1-34) [teriparatide] may be indicated for men with very low BMD or in those in whom bisphosphonate therapy is unsuccessful. The use of testosterone-replacement therapy for the prevention and treatment of male osteoporosis remains controversial but likely to benefit osteoporotic men with evident hypogonadism.