[Diagnosis and treatment of osteoporosis in male hypogonadism]

Sex steroid hormones such as testosterone and estrogen are involved in bone metabolism. In addition, various growth factors and cytokines also participate in the metabolism. However, their involvement remained to be determined. Androgen deprivation therapy (ADT) has a potential to induce osteoporosis and bone fracture. Their incidences clearly increase over time after the therapy. Bisphosphonate treatment is clinically expected for improvement of bone lesion induced by ADT, which will be determined by future clinical studies. Androgen replacement therapy (ART) has not been established for bone-related symptoms and findings in partial androgen deficiency of the aging male. Although evidence that ART may have favorable clinical effects on bone pathology has been accumulated, further studies including those for drug preparations should be needed.