Abstract 3495: Obesity and Development of New Atrial Fibrillation in the Women’s Health Study

Abstract

Obesity and atrial fibrillation (AF) are increasing public health problems, especially among women. Overweight and obesity (as defined by WHO criteria) have been previously associated with incident AF in existing cohorts; however, relatively few women with AF were included. We sought to further characterize the risk of incident AF over the entire range of body mass index (BMI) in a large prospective cohort of women enrolled in the Women’s Health Study. Women included in this analysis provided information on BMI and were free of cardiovascular disease and AF at baseline. Among the 38,807 women, 1022 incident AF cases were reported (9.8 +/− 1.2 person-years of AF). Compared with women not reporting AF, those who developed AF were older (58.8 +/− 8.0 vs 54.4 +/− 6.9 years), had higher BMI (27.2 +/− 5.7 vs 26.0 +/−5.0 kg/m2), and were more often diabetic (4.3% vs 2.5%), hypertensive (41.5% vs 2.5%), and hyperlipidemic (35.4% vs 29.1%), p < 0.0001 for each comparison. Continuous BMI was associated with AF in age-adjusted (HR 1.05; 95%CI, 1.04 –1.06) and multivariable Cox proportional hazards models controlling for age, diabetes, hypertension, hyperlipidemia, smoking, and physical activity (HR = 1.04; 95%CI, 1.03–1.05, p < 0.0001). When BMI was divided into 7 pre-specified categories, risk of AF was significantly increased among those with a BMI > 30 (see graph). Compared with women with BMI < 21, women with BMI > 35 were at 1.90-fold (95%CI, 1.42–2.55) increased risk of AF even after controlling for the listed obesity-associated comorbidities. Conclusion: These prospective data suggest a nonlinear relationship between BMI and risk of AF, with significant risk above a BMI threshold of 30 kg/m2.