Obesity Is an Independent Risk Factor for Heart Failure: Zona Franca Cohort Study

Background: Heart failure (HF) is a major problem in developed countries. However, its relationship with obesity remains unclear, especially in low-risk populations. The objective of the study was to analyze the relationship between obesity and HF in a low-risk Mediterranean population. Hypothesis: Obesity is an independent predictor for HF. Methods: A prospective community-based population cohort study with 10 years' follow-up was conducted at 2 healthcare centers in the city of Barcelona, Spain. From a registered population of 35 275, the study included 932 randomly selected patients without HF, age 35-84 years. Obesity was defined as body mass index (BMI) >= 30 and HF according to European Society of Cardiology guidelines, confirmed by echocardiography. Cox proportional hazards regression was used to examine the association between obesity and heart failure. Results: The difference in HF incidence between obese subjects (4.7%) and nonobese subjects (1.6%) was 3.1% (95% confidence interval [CI]: 0.7-5.5). In the unadjusted model, incident HF was significantly associated with BMI: the hazard ratio [HR] was 1.09 for every 1 kg/m(2) increase (95% CI: 1.05-1.14) and 3.01 for BMI >= 30 (95% CI: 1.34-6.77). After adjusting for age, sex, hypertension, ischemic heart disease, and diabetes mellitus, the results were similar: HR 1.06 (95% CI: 1.01-1.10) and HR 2.45 for BMI >= 30 (95% CI: 1.02-5.61). Overweight was not associated with HF in any of the models. The population-attributable risk of HF due to obesity was 43.0% (95% CI: 13.9-74.9). Conclusions: High rate differences, HRs, and attributable risk indicate that obesity is an important risk factor for incident HF.