Gender differences in patterns of relationship between body mass index and AF incidence

Abstract Background Obesity is reportedly associated with the new incidence of atrial fibrillation (AF). However, gender differences in patterns of relationship between body mass index (BMI) and the risk of AF are unknown. Methods We analyzed 21,382 middle-aged Japanese subjects (10923 men, 10459 women) without AF from a cohort of employees undergoing annual health examinations, with a follow-up period of 4.8±3.7 years. We examined the relationship between BMI at baseline to AF incidence in unadjusted and adjusted analyses. This relationship was also studied using linear and quadratic models. Results AF had developed in 137 subjects (119 men; mean age, 54.4±8.2 years; incidence, 2.19 and 0.38 per 1000 person-years in men and women, respectively). In multivariable Cox proportional-hazard models, increasing age (hazard ratio [HR], 2.72 per year; 95% CI, 2.22 to 3.33; P