The metabolic and cardiovascular consequences of HRT.

Hormone replacement therapy comprises natural oestrogen and, when appropriate, progestogen given to postmenopausal women. Population studies have shown that postmenopausal oestrogen administration results in a marked reduction in cardiovascular disease, particularly coronary heart disease, an effect that does not appear to be lost when cyclical progestogen is also included. The way in which the hormones confer this protection has not been fully elucidated, but it includes effects on metabolic processes that contribute to atheroma formation as well as direct effects on the arteries themselves. Oestrogens and progestogens can produce beneficial changes in lipids and lipoproteins, glucose and insulin metabolism, body fat distribution, and coagulation and fibrinolysis. Oestrogen acts directly on blood vessels through both endothelium-dependent and calcium-dependent mechanisms to improve arterial function. More widespread use of HRT could result in a major beneficial impact on cardiovascular disease, the leading cause of death in women.