Oestrogens and bone metabolism: a hypothesis

The explanations so far proposed for the effects of oestrogens on bone metabolism in post-menopausal women have been based on the changes seen in calciotrophic hormones. However, we demonstrated in a previous study [6] that there is a decrease in the concentration of somatomedin (an insulin-like growth factor) and an increase in that of growth hormone (GH) in oestrogen-treated post-menopausal women. On the basis of those findings and the relevant data published in the literature, we advance a hypothesis to the effect that the bone-metabolism changes that occur in post-menopausal women following oestrogen replacement therapy come about via changes in serum somatomedin and growth hormone concentrations.