While most of the medical community’s efforts in improving skeletal health have focused on the diagnosis and treatment of postmenopausal osteoporosis, osteoporosis in men remains a common condition associated with significant public health and economic ramifications. Compared to women, men generally begin to experience fragility fractures about 10 years later in life and at approximately one third the rate at most anatomic sites. Despite this lower prevalence, however, it is notable that the morbidity and mortality associated with fragility fractures is significantly higher in men than in women, with studies consistently reporting male post-hip fracture mortality rates as high as 20-30%. Despite the significant individual and societal costs of male osteoporosis, however, and the increasing number of national and international professional societies that have published screening and management guidelines, osteoporosis in men remains a condition that is seldom diagnosed and rarely treated.
While the pathophysiology of osteoporosis in men has similarities to the pathophysiology in women, there is no single factor in men that is analogous to the rapid, high-turnover bone loss that occurs in early postmenopausal women secondary to estrogen deficiency. Importantly, however, over the past several years a great deal of observational and experimental research (both animal and human) has allowed us to begin to develop a better understand of the diverse mechanisms that contribute to skeletal fragility and fracture risk in men. These studies have focused on a variety of underlying components including genetic influences, behavioral factors (nutrition and physical activity), the effects of body composition and muscle, concomitant medical conditions, long-term medication exposure, and the changing hormonal milieu throughout the male lifespan. In this session, we will review the epidemiology and pathophysiology of osteoporosis in men with a specific focus on the role that gonadal steroids and other hormonal factors play in male bone metabolism.