HRT and osteoporosis.

Hormone replacement therapy is well documented to reduce the increased bone turnover induced by oestrogen deficiency and, as a result, it prevents bone loss after the menopause. It has been shown that this effect leads to a significant reduction in osteoporotic fracture rates. There is a dose threshold effect, the duration of therapy influences the degree of benefit and, after the cessation of HRT, postmenopausal bone loss resumes. Women take HRT for many reasons, most for relief of menopausal symptoms, and 10-20% show poor compliance. The nature of HRT preparations is discussed and the current understanding of benefits and risks described.