The Role of Sex Steroids in the Pathogenesis of Osteoporosis

Significant bone loss occurs with aging in both men and women, leading to alterations in skeletal microarchitecture and increased fracture incidence. Much work has now significantly enhanced our understanding of the role that sex steroids (primarily estrogen and testosterone) play in the development and progression of osteoporosis in both men and women. In addition to changes in bone mass that occur with aging, changes in bone cross-sectional area also occur in both sexes across skeletal sites. The relationship between diminishing estrogen levels in women caused by ovarian failure and the development of postmenopausal osteoporosis has been recognized for seven decades. It is likely that intrinsic changes occur in osteoblast and perhaps osteoclast lineage cells with aging. These changes, which are likely independent of changes in sex steroids or other hormonal factors, are the focus of ongoing animal and human studies.