Abstract 14191: Obesity Index and the Risk of Atrial Fibrillation in an Urban Japanese Cohort: The Suita Study
Background and purpose: Atrial fibrillation (AF) is the most common chronic kind of arrhythmia and is associated with an increased risk of mortality and stroke. However, few prospective studies have examined the influence of obesity on the incidence of AF in a general population. We assessed the relationship between the obesity index and the risk of incident AF in a 12.3-year prospective study of an urban general population in Japan.
Methods: A total of 6,570 participants (30 to 79 years old) in the Suita Study were initially free of AF and prospectively followed up for incident AF. Participants were diagnosed with AF if AF or atrial flutter was present on an electrocardiogram or if AF was indicated as a present illness on questionnaires from a routine Suita health check-up examination (every 2 years). Body mass index (BMI) was calculated as weight (kilograms) divided by height (meters) squared. The waist and hip circumferences (WC and HC) were measured in a standing position at the umbilical level and the largest circumference, respectively. Body fat was measured by 4-channel impedance methods. Skin-fold thickness (SFT) was measured and summed at the lower part of scapula and the posterior region of triceps, by caliper. The risk of AF across obesity index was assessed using Cox proportional-hazards models.
Results: During 12.3 years of follow-up, 207 incident AF events occurred (3.73 and 1.60 per 1,000 person-years for men and women, respectively). Compared with the BMI (<20.4 kg/m2), the adjusted hazard ratios (HRs; 95% confidence intervals; 95% CIs) of incident AF for the BMI (≥24.5 kg/m2) was 1.58 (1.05 to 2.39). The HR (95% CIs) for incident AF was 1.06 (1.01 to 1.11) for 1 kg/m2 increases in BMI. The interaction between sex and BMI for incident AF was not statistically significant (P=0.91). Compared with the 1st quartile for HC, the 4th quartile of HC had increased risk of AF (HR=1.7; 95% CIs, 1.08 to 2.67). There were no association between WC, SFT, and body fat and incident AF. After putting weight and height into all the models, weight was still a statistically significant factor (HR=1.02; 95%CIs, 1.00 to 1.04).
Conclusion: BMI, HC, weight is an important risk factor for incident AF in a community-based sample in Japan. Appropriate weight control is important for preventive AF.
- © 2011 by American Heart Association, Inc.