Sex hormones and cardiovascular risk

Abstract

Inspection of the age-incidence curve of ischaemic heart disease in both sexes shows an increase in slope for women around the menopause, approaching that of men at older ages. Although the increase is likely to be related to the menopause, epidemiological evidence is not defined. Likewise, there is some suggestion that reproductive factors may be related to the subsequent risk of cardiovascular diseases, since a few studies found an elevated risk in women with an earlier first birth. In terms of prevention and public health considerations, treatments via exogenous hormones are, however, much more important. A systematic overview of the available epidemiological evidence indicates that oestrogen replacement treatment is protective against ischaemic heart disease. The overall relative risks based on 18 studies and greater than 3300 cases was 0.81, with a narrow 95% confidence interval (0.76-0.85), thus suggesting a protective effect of 15-25%. This protection has a plausible biological interpretation in terms of increased high density lipoprotein (HDL) levels. The serum lipoprotein pattern can be unfavourably influenced by progestin supplementation. With reference to oral contraceptives, the relative risk for cardiovascular mortality was increased about twofold in current users. There appears now to be convincing evidence that the elevated risk is restricted to current users.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: The slope of the cardiovascular disease incidence curve is lower for women than for men before age 50, after which it either equals or surpasses that of men. Studies have not been able to differentiate between the role of menopause and the effect of age in this increased risk, however. Some studies have identified elevated ischemic heart disease risks in women whose 1st pregnancy occurred in their early to mid-20s and nulliparous women. An analysis of 18 studies shows that estrogen replacement therapy in postmenopausal women exerts a 15-25% protective effect against ischemic heart disease. This protection may be due to increased levels of high density lipoprotein. Studies do not yet support the cardiovascular benefits of combined estrogen-progestin therapy. In fact, progestin may adversely affect the serum lipoprotein pattern. Various cohort studies of oral contraceptive (OC) use and ischemic heart disease and cerebrovascular disease indicate that current OC users have an overall 2-fold increased risk of these diseases, but data do not find this risk in former OC users. The relative risk for ischemic heart and cerebrovascular diseases among current OC users is even greater in smokers (up to 39). This also holds true for the newer low strength, low potency OCs. Over the years, however, OCs have changed from high strength, high potency OCs to low strength, low potency OCs. Research is already showing that the cardiovascular risks were higher with the high strength, high potency OCs. Research also reveals an elevated risk of ischemic heart disease among current OC users 35-years old and among those who are at excess risk for reasons other than OC use. The low strength, low potency OCs even appear to have a protective effect against breast cancer. These results provide physicians with guidelines to selective prescription of OCs.