Objective: Metabolic disturbances may explain the increased cardiovascular risk associated with reproductive factors. This cohort study investigated the relationship between reproductive factors and coronary artery calcification in elderly women and whether this relationship could be explained by metabolic disturbances.
Design: In total, 568 postmenopausal women were included in this cross-sectional study. Information about the women's reproductive life was obtained by a questionnaire. Metabolic factors were measured during a single visit. Coronary artery calcification was assessed with a multislice computed tomography scanner and dichotomized as absent or present. Logistic regression analysis was used to assess the relationship between reproductive factors and coronary artery calcification. Crude and multivariate adjusted odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. In addition, ORs were adjusted for several metabolic and cardiovascular risk factors.
Results: The mean age was 66.9 (+/- 5.5) years. Women with a history of irregular menstrual cycle lengths, as opposed to women with a history of regular menstrual cycles (26-30 d), had an increased risk of coronary artery calcification; multivariate-adjusted OR = 2.73 (95%CI: 1.24-5.98). Four or more pregnancies, compared with never pregnant, yielded an multivariate-adjusted OR of 1.89 (95% CI: 1.00-3.58). Having four children or more, compared with having no children, yielded a multivariate-adjusted OR of 1.97 (95% CI: 1.00-3.89). Adjustment for metabolic factors and other cardiovascular risk factors did not fully explain theses relationships.
Conclusion: Multigravidity (more than four pregnancies), multiparity (more than four births), and irregular menstrual cycle lengths were related to an increased risk of coronary artery disease. These associations could not be explained by metabolic abnormalities.