Examining Healthy Lifestyles as a Mediator of the Association Between Socially Determined Vulnerabilities and Incident Heart Failure

Background: Increased burden of socially determined vulnerabilities (SDV), which include nonmedical conditions that contribute to patient health, is associated with incident heart failure (HF). Mediators of this association have not been examined. We aimed to determine if a healthy lifestyle mediates the association between SDV and HF.

Methods: We included adults aged 45 to 64 years old across the United States from the REGARDS cohort study (Reasons for Geographic and Racial Differences in Stroke) without evidence of HF at baseline. The primary exposure was a count of SDV based on the Healthy People 2030 framework. The primary outcome was incident HF. We assessed the role of a healthy behavior score (HBS range, 0-8) and its components (adherence to a Mediterranean diet, physical activity, lack of sedentary lifestyle, and smoking abstinence) as potential mediators of the association between SDV and incident HF.

Results: We included 13 on 525 participants. The median HBS was 4, with 16% with low HBS (0-2), 55% with moderate HBS (3-5), and 29% with high HBS (6-8). Increasing burden of SDV was associated with a stepwise increase in incident HF (adjusted hazard ratio, 1.84 [95% CI, 1.32-2.52] for 1 SDV, 2.59 [95% CI, 1.87-3.60] for 2 SDV, and 4.20 [95% CI, 3.08-5.73] for ≥3 SDV). There was no statistically significant mediation of HBS for the association of SDV count of 1 and incident HF. HBS score mediated 10.6% of the association between SDV count of 2 and incident HF and 11.1% of the association for those with ≥3 SDV. This increased to 10.8% and 18.3%, respectively, in the complete case analysis. Regarding individual components of HBS as mediators, only avoidance of a sedentary lifestyle was statistically significant (8.6% mediation) for the association of SDV count of 2 and incident HF.

Conclusions: A healthy lifestyle plays a small role in mediating the association between high SDV count and incident HF.