Body Size and Atrial Fibrillation in Japanese Outpatients

BACKGROUND: Although recent studies have suggested that height and body mass index (BMI) independently affect the prevalence of atrial fibrillation (AF), their combined effects have not been fully examined in Japanese patients. METHODS AND RESULTS: Patients without organic cardiac diseases, hypertension and diabetes mellitus were screened from a prospective, single hospital-based cohort of the Shinken Database 2004-2007 (n=4,719). Both height and BMI significantly increased the crude rate of AF prevalence and the effects were significant even after adjustment by age, sex and left atrial dimension. The relative risks (RRs) for AF in the height and BMI categories were 2.07 (95% confidence interval [CI] 1.70-2.52) and 1.78 (95%CI 1.46-2.17), respectively, in the highest tertile compared with the lowest tertile. The RRs in the highest combined tertile was high to 2.98 (95%CI 2.07-4.28) compared with the lowest combined tertile, an unignorable figure for AF prevalence in the future. CONCLUSIONS: Height and BMI synergistically affected the prevalence of AF in Japanese patients. With respect to the recent increase in body size of the Japanese population, the present study predicts that there will be more occurrences of AF than previously predicted. (Circ J 2010; 74: 66 - 70).