Severity of cardiovascular disease in women: Relation with exposure to endogenous estrogen

Abstract

Objectives Coronary artery disease (CAD) is more common in men than in women. Endogenous sex steroids may be the main factor responsible, as long-term estrogen action appears to be protective. The aim of the study was to investigate the predisposing factors responsible for the severity of CAD in women. Methods One hundred and eight women (100 menopausal) undergoing coronary angiography were studied. Reproductive function was recorded. The severity of CAD was assessed by the number of arteries with severe stenosis, the presence of angina and myocardial infarctions (MI). Results The time since menopause (TSM) was significantly longer in women with angina and with MIs compared to those without (20.3 ± 8.7 years versus 15.8 ± 8.7 years and 22.6 ± 8.6 years versus 18.1 ± 8.9 years, p < 0.05), independently of chronological age. The age at menopause was significantly younger in women who had 2 MIs compared to those with 1 or 0 MI (41.5 ± 3.5, 47.5 ± 5.3 and 48.4 ± 5.4 years, respectively; p = 0.04); the total duration of menstrual cyclicity was inversely related to the number of MIs (35.6 ± 5.8, 34.2 ± 5.3 and 28.3 ± 3.3 years, 0, 1 and 2 MIs, respectively; p = 0.03). Conclusions The severity of CAD in women referred for coronary angiography is correlated with measures of exposure to endogenous estrogen. Both the TSM and the age at menopause are aggravating factors for MI, independently of age. There is an independent protective effect of the duration of estrogen exposure on the number of MIs; this has not been reported before and supports the protective role of the length of exposure to endogenous estrogen, especially for the occurrence of MI in this selected group of women.