Interaction of blood pressure and body mass index with risk of incident Atrial fibrillation in a Japanese urban cohort: The suita study

BACKGROUND AND PURPOSE To prevent stroke, strategies for atrial fibrillation (AF) prevention and an early detection of AF by electrocardiogram are essential. However, only a limited prospective studies have examined the risk factors for AF, even in blood pressure (BP) and body mass index (BMI), which are not clear among general populations. We investigated the impacts of BP and BMI on the risk of incident AF in a general population. METHODS A total of 6,906 participants (30-84 years) in the Suita Study were prospectively followed up for incident AF. Participants were diagnosed with AF if AF or atrial flutter was present on an electrocardiogram from a routine health examination (every 2 years) or if AF was indicated as a present illness from health examinations and/or medical records during follow-up. Adjusted Cox proportional hazard ratios (HRs) were calculated. RESULTS During the 12.8-year follow-up, 253 incident AF events occurred. Compared with the systolic BP (SBP) < 120mm Hg and normal-weight, the adjusted HRs (95% confidence intervals; CIs) of incident AF in the systolic hypertension and the overweight (BMI ≥ 25kg/m²) groups were 1.74 (1.22-2.49) and 1.35 (1.01-1.80), respectively. Compared with SBP < 120mm Hg and normal weight, the adjusted HRs (95% CIs) of incident AF in the SBP = 120-139mm Hg with overweight and the systolic hypertension with normal or overweight were 1.72 (1.01-2.91), 1.66 (1.10-2.50), and 2.31 (1.47-3.65), respectively (P for interaction = 0.04). CONCLUSIONS Systolic prehypertension and overweight are associated with incident AF in Japanese population. The association between SBP and AF may be evident by overweight.