Behavioral Factors Mediated the Impact of Educational Attainment on Incident Heart Failure: A Mediation Analysis

Abstract

Background: Low educational attainment is associated with increased HF risk, but to our knowledge, the underlying mechanisms remain unknown. We aimed to examine the association of low educational attainment with incident heart failure (HF) and explore potential behavioral mediators of the causal pathway. Methods: A total of 12,109 participants in the ARIC (Atherosclerosis Risk in Communities) Study were included in this study. Educational attainment was measured at baseline. We assess the risk of HF across educational attainment group based on Cox proportional hazards models. Using mediation analysis, we evaluated the mediating role of behavioral factors in the causal pathway between educational attainment and HF. Results: 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 for low and medium educational attainment with high as reference was 1.41 (95% CI, 1.26 to 1.57) and 1.13 (95% CI, 1.02 to 1.25), respectively. In mediation analysis, the association between educational attainment and HF was partially mediated by income, waist-to-hip ratio, current smoking, BMI, current drinking, sports and physical activity, which explained 24.3%, 20.2%, 13.8%, 10.1%, 7.7%, 7.3% and 4.5% of the relationship. In total, all mediators contributed to 56.3% of the total effect. Interpretation: In this observational cohort study, low educational attainment was associated with significantly increased risk for HF. Income, obesity and current smoking mediated a great proportion of the total effect of educational attainment on HF, respectively. Our results provide the underlying insights for development of targeted public health intervention to reduce educational disparities on HF. Funding Statement: This study was supported by the National Natural Science Foundation of China (81600206 to ZXD; 81870195 to LXX), and Natural Science Foundation of Guangdong Province (2016A030310140 to ZXD;20160903 to LXX). Declaration of Interests: The authors have no conflicts of interest to disclose. Ethics Approval Statement: The Institutional Review Boards (IRB) approved the ARIC protocol, and all participants gave informed consent at each visit.