Vascular complications of long-term oestrogen therapy.

Long-term low dose oestrogen therapy has a protective effect on bone mineral content in the post-menopausal or castrated female. As yet the only obvious clinical side effect of such therapy has been transient leg muscle cramps. Several biochemical side effects could be observed. Low dose mestranol caused a persistent elevation of factor VII and a dose-dependent increase in both factors VII and X was observed using oestriol hemisuccinate. Such effects are more likely to be dose-related than related to the type of oestrogen prescribed. Effects of oestrogens on lipids, and cholesterol in particular, may be dose-related also. Changes in blood pressure in post-menopausal women are more likely to be related to obesity than to oestrogen treatment which would seem to have a protective effect against weight increase. No marked changes in the mean risk score for ischaemic heart disease could be detected during oestrogen treatment.