Model Analysis of the American Heart Association's Life's Essential 8: Can Physical Activity Mitigate Cardiovascular Risk Among Low-Income Individuals?

BACKGROUND: Life's Essential 8 provides a comprehensive framework linking modifiable behavioral and biological factors to cardiovascular risk. This study evaluated a multimediation model to explain how low income is associated with cardiovascular risk indexed by blood pressure.

METHODS: National Health and Nutrition Examination Survey (2021-2023) data were analyzed among community-dwelling US adults (n=3345). A multimediation path analysis tested a behavioral-to-biological pathway from income through health behaviors (moderate-to-vigorous physical activity [MVPA], sleep, nutrition, and smoking) to biological measures (body mass index, low-density lipoprotein cholesterol, and fasting glucose), with systolic blood pressure as the end point.

RESULTS: Low income was associated with lower MVPA (β=0.11, P<0.001), lower nutrition (β=0.11, P<0.001), and increase in smoking (β=0.40, P<0.001). Total indirect effects indicated that low income was associated with higher fasting glucose (β=-0.10 [95% CI, -0.128 to -0.066]; P=0.010), body mass index (β=-0.10, [95% CI, -0.134 to -0.069]; P=0.006), and systolic blood pressure (β=-0.12 [95% CI, -0.146 to -0.088]; P=0.006). Low MVPA was associated with higher systolic blood pressure (β=-0.03 [95% CI, -0.056 to 0.000]; P=0.048), fasting glucose (β=-0.07, P<0.001), and body mass index (β=-0.08, P<0.001).

CONCLUSIONS: Low income was associated with unhealthy behaviors and indirect associations with adverse biological outcomes and elevated systolic blood pressure. MVPA demonstrated the strongest behavioral association, suggesting that promoting MVPA may mitigate income-related cardiovascular risk and inform community-based trials among low-income individuals.