Cardiovascular
Hypothetical interventions on lifestyle factors to reduce racial and sex differences in incident heart failure: a causal mediation analysis Han-Chih Hsieh* Chanelle Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Howe Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA
Race and sex differences in incident heart failure (HF) remain substantial in the US. Modifiable lifestyle factors (e.g., physical activity (PA) and diet) may be mediators. We quantified the extent to which hypothetical interventions that achieved recommended PA levels or yielded healthier diets reduced race and sex differences in incident HF.
A causal mediation analysis was performed among Black and White males and females included in harmonized data from 8 US cohorts (i.e., WHI, FHS, ARIC, Health ABC, REGARDS, CARDIA, CHS, and MESA). We used Aalen-Johansen estimators—inverse probability weighted based on lifestyle, clinical, or sociodemographic factors—to estimate RDs for incident HF by race or sex for the first 15 years of follow-up. This estimator accounted for measured sources of selection and confounding bias, and the competing risk of death. Time zero was study entry or a later time when necessary data were available. RDs were calculated before and after a hypothetical intervention on PA or diet. The PA intervention set all participants at time-zero to exercise moderately or vigorously for 150 mins/wk, or vigorously for 75 mins/wk. The diet intervention set all participants at time zero to be in the top two quintiles of the Alternative Healthy Eating Index 2010. RDs before and after the intervention were used to calculate a PE, the proportion of the pre-intervention race or sex difference that would be eliminated due to the intervention. Race and sex analyses were performed among participants who were 26-98 years old at time zero (n=61,290). Race analyses were also among participants who were <=55 at time zero (n=13,317).
Among participants of all ages at time zero, race differences at year 15 of follow-up were reduced after both interventions. The same result was observed among participants aged <=55 at time zero. Sex differences at year 15 were not reduced (Figure). Real world interventions on PA or diet may reduce race differences in incident HF in the US.
