Changes in serum somatomedin and growth hormone concentrations after 3 weeks oestrogen substitution in post-menopausal women; a pilot study.

Oestrogens have a preventive effect on bone loss in post-menopausal women; however, little is known about their mechanism of action. The aim of this study was to investigate the changes in somatomedins (SM) and growth hormone (GH) concentrations in serum in post-menopausal women after 3 weeks of substitution with 20 micrograms ethinyloestradiol. A significant decrease was observed in the mean serum levels of SM, measured by bioassay (0.66 +/- 0.07 vs 0.38 +/- 0.07, P less than 0.01), radioimmunoassay (0.62 +/- 0.08 vs 0.34 +/- 0.03, P less than 0.01) and radioreceptorassay (1.14 +/- 0.11 vs 0.90 +/- 0.09, P less than 0.01). The mean serum GH concentration increased (9.4 +/- 3.2 vs 16.5 +/- 4.6, P less than 0.01). A positive role of SM and GH in the changes of bone metabolism after oestrogen substitution in post-menopausal women is discussed.