Abdominal Aortic Aneurysm Events in the Women's Health Initiative: Cohort Study

Abstract

Conclusion: There is a strong positive association with age and smoking and abdominal aortic aneurysm (AAA) in women. There is a negative association with diabetes. Summary: Aortic aneurysms are more common in men but may be more deadly in women. The Women's Health Initiative (WHI) involved clinical investigation of strategies of prevention of common diseases in 161,808 women. The authors used these data to assess for associations between potential risk factors for AAA and subsequently clinically important AAA events, rupture, and repair in postmenopausal women. This was a cohort analysis of data from the WHI. Mean follow-up was 7.8 years. The WHI enrolled women who were postmenopausal and aged 50 to 79 years. The main outcome measure was the association of self-reported or measured baseline variables with AAA repair or rupture. AAA events occurred in 184 women. Events were strongly associated with age and smoking. Ever smoked, current smoking, and amount smoked all contributed independent risks. Additional positive associations were seen for height, cholesterol-lowering treatment, hypertension, and coronary and peripheral arterial disease. There was a negative association with diabetes (odd ratio, 0.29; 95% confidence interval, 0.13-0.68) and with postmenopausal hormone therapy. Comment: Although the incidence of AAA is significantly lower in women than in men, most risk factors for AAA and negative associations appear to be the same for men and women. The authors also found a negative association between AAA in women and postmenopausal hormone therapy, which suggests that estrogen may have a favorable effect in reducing the development of AAA in women. However, other studies found increased aneurysmal disease in patients treated with hormone therapy. It therefore remains unclear why the prevalence of AAA differs so much by sex. One may postulate a thus far unknown gender-associated biologic explanation. There may also be unknown confounders of lifestyle in the WHI data. It does appear, however, that the negative association between AAA and diabetes is solid for both men and women.