Endocrine Abstracts

Steroid hormones play an important role in the skeleton and may be involved in the pathogenesis and management of osteoporosis. The decline in estrogen levels at the menopause is associated with increased bone resorption and accelerated bone loss. Although there is no comparable reduction in serum testosterone in middle-aged men, the gradual decline in free testosterone may contribute to bone loss with age. Hypogonadism is a well-established cause of secondary osteoporosis in men, but it is now clear that the effects of testosterone on the male skeleton are mediated in part by aromatisation to estrogen.

Although hormone replacement therapy (HRT) improves bone mineral density (BMD) and decreases the incidence of fractures in postmenopausal women, it should no longer used in the prevention of osteoporosis, as the risks outweigh the benefits. Nevertheless, HRT may be useful in the management of younger postmenopausal women with osteoporosis who have climacteric symptoms or are unable to tolerate other treatments. Testosterone replacement improves BMD in hypogonadal men with osteoporosis, but any decision about its use should be influenced by an assessment of the risks and benefits.

Oral glucocorticoid treatment is associated with rapid bone loss and increased risk of fractures. The increased fracture risk is partly independent of BMD, as patients on glucocorticoids fracture at a higher BMD than other subjects of the same age. Although oral glucocorticoid treatment is a common cause of osteoporosis, bisphosphonates improve BMD and decrease the incidence of vertebral fractures. Recent Guidelines from the Royal College of Physicians suggest that osteoporosis should be considered in any patient on oral glucocorticoids for three months. In those with a previous fragility fracture or above the age of 65 years, osteoporosis treatment is recommended without the need for BMD measurement. In younger patients without previous fracture, BMD measurement is advocated, with treatment recommended when the T Score is < -1.5.