The assessment of bone mass in men

Bone mineral density (BMD) is widely used in postmenopausal women to identify who should be given therapy for prevention and treatment of osteoporosis and to monitor the efficacy of treatment. There is still uncertainty about how to interpret BMD in men, and few prospective studies exist on the relationship between BMD and fracture risk. Men should be considered for measurement of BMD if they have suffered low trauma fractures, have prevalent vertebral deformities, have radiographic osteopenia, are over age 75, or have conditions that increase their risk for bone loss, such as hypogonadism, glucocorticoid use, or generally poor health. There is insufficient information to recommend a more widespread BMD screening. The World Health Organization has developed criteria for interpreting BMD which are widely used. Patients with BMD at least 2.5 SD below the young adult mean (T-score < -2.5) have osteoporosis, and those with BMD between 1 and -2.5 SD below the young adult mean (-2.5 < T-score < -1.0) have osteopenia. However, the BMD criteria that should be used to identify men in need of therapeutic intervention are still debated. Using male-specific hip BMD cutoffs, approximately 3-6% of U.S. men 50 years and older were estimated to have osteoporosis and 28-47% to have osteopenia. The corresponding figures in women were 13-18% with osteoporosis and 37-50% with osteopenia. Greater accumulation of skeletal mass during growth, slower rate of bone loss, and shorter life expectancy in men contribute to the lower prevalence of osteoporosis relative to women.