Abstract 18714: Predictors of Incident Abdominal Aortic Aneurysm in The Elderly: Insights from the Southern Community Cohort Study
Background: Abdominal aortic aneurysm (AAA) is a leading cause of death in the United States, with high prevalence in the elderly population. We sought additional insight into the incidence and predictors of AAA among elderly persons with documented lifestyle and socioeconomic characteristics.
Methods: Among 11,013 elderly (≥ 65 years) participants in the Southern Community Cohort Study who were also Medicare recipients from 1999-2008, we calculated age-adjusted incidence rates (IR) of AAA. We assessed the predictors of incident AAA using Cox proportional hazards regression analysis, adjusting for demographic, lifestyle, socioeconomic factors, and medical history. Participants with prevalent AAA at baseline were excluded from this analysis.
Results: Overall, 198 incident AAA cases were identified during the study period. Age-adjusted IR (per 100,000) were 528, 1267, 247 and 590 among black men, white men, black women and white women, respectively. After adjusting for known risk factors, women had lower risk for AAA compared with men (Hazard ratio (HR) 0.59, 95% CI 0.43-0.81; Table) and blacks had lower risk compared with whites (HR 0.42, 95% CI 0.31-0.59). Smoking remained the strongest risk factor overall (former: HR 2.14, 95% CI 1.40-3.30; current: HR 5.09, 95% CI 3.25-7.95), and this association was most pronounced among women. Hypertension and myocardial infarction or coronary artery bypass surgery were each positively associated with AAA incidence among men (respective HR 1.84, 95% CI 1.13-2.99 and 1.68, 95% CI 1.06-2.66). Interestingly, the presence of diabetes mellitus (DM) was inversely associated with incident AAA (overall HR 0.68, 95% CI 0.47-0.99).
Conclusion: Smoking and HTN were independent predictors of increased risk of incident AAA in this cohort, while female sex, black race, and DM confers protective effects. The underlying mechanism(s) for these protective effects remain incompletely understood and warrant further evaluation.
- © 2012 by American Heart Association, Inc.