Behavioral Factors Mediating the Impact of Educational Attainment on Incident Heart Failure　― A Mediation Analysis ―

BACKGROUND: To examine the association of low educational attainment with incident heart failure (HF) and explore potential behavioral mediators of the causal pathway. METHODS AND RESULTS: A total of 12,109 participants in the Atherosclerosis Risk in Communities Study (ARIC) were included. Educational attainment was measured at baseline, and the risk of HF across educational attainment groups was assessed by Cox proportional hazards models. Using mediation analysis, we evaluated the mediating role of behavioral factors in the causal pathway between educational attainment and HF. During a median follow-up of 25.1 years, 2,407 cases (19.9%) of HF occurred. Educational attainment showed an inverse association with HF risk (hazard ratio (HR), 1.41; 95% confidence interval (CI), 1,26-1.57 for low educational attainment; HR, 1.13; 95% CI, 1.02-1.25 for medium educational attainment). In the mediation analysis, the association between educational attainment and HF was partially mediated by income, waist-to-hip ratio, current smoking, body mass index, current drinking, sports and physical activity, which explained 24.3%, 20.2%, 13.8%, 10.1%, 7.7%, 7.3% and 4.5%, respectively, of the relationship. In total, all mediators contributed 56.3% of the total effect. CONCLUSIONS: Low educational attainment was associated with increased risk for HF. Income, obesity and current smoking mediated a great proportion of the total effect of educational attainment on HF. Our results provide underlying insights for the development of targeted public health interventions to reduce educational disparities on HF incidence.