Metabolic effects of the menopause and oestrogen replacement.

There is little doubt that the metabolic disturbances seen following the loss of ovarian function are most important in the development of cardiovascular disease in women. The loss of hormones at the menopause appears to reduce both insulin secretion and elimination, but increasing insulin resistance thereafter brings about an increase in circulating insulin concentrations. Changes in lipids and lipoproteins are in an adverse direction, as are changes in body fat distribution, and changes in haemostatic factors would tend to favour coagulation rather than fibrinolysis. HRT with oestrogen appears to improve most of the metabolic abnormalities related to the menopause, but this is in part dependent on the type of oestrogen used and the route of administration. The addition of progestogen may influence the metabolic changes induced by oestrogens, and this will vary according to the type of the progestogen. Overall, the metabolic effects of any of the current HRT regimens would seem likely to be beneficial for CHD. Nevertheless, future HRT regimens should ideally be tailored to produce the most favourable changes in CHD metabolic risk factors, particularly in the case of the regimens which attempt to avoid cyclical bleeding.