Family history of myocardial infarction predicts incident coronary heart disease in postmenopausal women with diabetes: the Women's Health Initiative Observational Study

Abstract

Diabetes is a risk factor for coronary heart disease (CHD) but CHD does not occur in all diabetic individuals. The goal of this study was to assess the relationship between family history of myocardial infarction (MI) and incident CHD in diabetic postmenopausal women. We conducted a prospective cohort study among 2642 diabetic postmenopausal women without CHD at baseline in the Women's Health Initiative Observational Study. Family history was defined as a proband report of MI in first-degree relatives. Incident CHD was defined as non-fatal MI, coronary revascularization, or CHD death. During 7.3 ( +/- 1.8) years of follow-up, 14.3% of the participants had incident CHD. The risk of incident CHD was 50% higher (HR = 1.50, 95% CI: 1.20-1.87, p = 0.0003) in those with a family history of an MI in at least one first-degree relative, and 79% higher (HR = 1.79, 95% CI: 1.36-2.35, P < 0.0001) if two or more first-degree relatives had an MI, compared to participants without a family history, after adjustment for covariates. The CHD risk increased with elevated systolic blood pressure (SBP) (HR = 1.01, 95% CI: 1.003-1.02, p = 0.001) but decreased with elevated diastolic BP (HR = 0.98, 95% CI: 0.97-0.999, p = 0.005) and with two or more episodes per week of physical activity (HR = 0.70, 95% CI: 0.52-0.93, p = 0.02). The results suggest that a family history of MI predicts CHD in diabetic postmenopausal women. Close attention should be paid to BP control and physical activity in these women.