[Sex steroids. Effects on the carbohydrate metabolism before and after menopause]

The action of female sex steroids on carbohydrate metabolism has clearly been demonstrated by numerous clinical and experimental studies. A beneficial effect of 17 beta oestradiol has been reported on insulin secretion and insulin sensitivity, inducing an improvement of glucose tolerance through an increase of glucose clearance by liver, muscle and adipose tissues. Progesterone has, to a lesser degree, the same stimulant effect on insulin secretion and improves glucose assimilation by the liver, although a relative insulin resistance is observed in the other two tissues. Menopausal hormonal privation does not significantly alter glucose tolerance in the absence of such predisposition factors as overweight or history of gestational or familial diabetes mellitus. The first trials of menopausal substitution with oral synthetic oestrogens, especially in doses of more than 50 micrograms per day, were responsible for the bad reputation of oestroprogestins due to their effects on metabolic parameters. As shown by prescription for contraceptive use, replacement therapy with oral synthetic oestrogens induces a diabetogenic tendency as well as hypertensive, dyslipidaemic and thrombogenic risks, especially when associated with progestins issued from nortestosterone. Reducing the oestrogen doses, using equine sulfoconjugates and selecting non-androgenic progestins has already minimized these deleterious effects. The present availability of oral or percutaneous natural 17 beta oestradiol and of norpregnanes calls for reconsideration of the glucidic risk due to oestroprogestin prescription. A few studies have already shown that in fact they can improve glucose tolerance. The recommended substitution of menopause to prevent atherosclerosis must lead to a better characterization of its glycaemic and insulinaemic effects.