Atrial fibrillation (AFib) is linked to increased risks of mortality and cardiovascular disease. There are several prospective studies examined the association of smoking and metabolic syndrome (Mets) with incident AFib in a general population. No study examined the combination of smoking and Mets on the AFib risk in a general population. We investigated whether the combination of smoking and Mets increased the risk of incident AFib in an urban Japanese population.Design and method:
The 6,901 Suita Study participants (30–84 years old) were initially free of AFib and prospectively followed up for incident AFib. Standard 12-lead ECGs were obtained from all subjects in the supine position. The participants were diagnosed with AFib if AFib or atrial flutter was present on ECGs obtained during a biannual routine health examination or if AFib was indicated as a present illness by questionnaire and medical records during follow-up. The Mets components were defined using the uniform definition proposed in the 2009 Joint Interim Statement, which constitutes the presence of any three or more of five components. We analyzed Cox proportional hazard ratios (HRs) and 95% confidence intervals (CIs) after adjusting for age, gender, smoking, excessive drinking, and Mets components at baseline.Results:
During the 13.5 years of follow-up, 305 incident AFib events occurred. The adjusted HR (95% CIs) of incident AFib for smoking was 1.47 (1.03–2.08); central obesity, 1.32 (1.02–1.73); high blood pressure, 1.64 (1.26–2.13); and Mets, 1.36 (1.07–1.73). Compared with no components, the adjusted HR (95% CIs) of incident AFib for any 3 or more components was 1.73 (1.17–2.56). Compared to non-smokers without components, the adjusted HRs (95% CIs) of incident AFib for non-smokers and smokers with Mets were 1.91 (1.13–3.21) and 2.34 (1.23–4.31), respectively. Notably among women, the adjusted HR (95% CIs) of incident AFib for smokers with Mets was 6.15 (2.11–17.9).Conclusions:
Smoking, central obesity, high blood pressure, and Mets are risk factors for AFib. Women with Mets, in particular, should stop smoking to avoid experiencing AFib. Quitting smoking, and maintaining appropriate blood pressure, and body composition are important for preventing AFib.