Association of Objective Physical Activity and Mortality in American Heart Association’s Life’s Essential 8

BACKGROUND: The American Heart Association's (AHA) Life's Essential 8 (LE8) highlights key factors for cardiovascular health, including physical activity (PA). However, existing research relies on self-reported PA data, which can be inaccurate. OBJECTIVES: The objective of the study was to evaluate the association between accelerometer PA measures and AHA LE8 + objective PA measures with all-cause and cause-specific mortality. METHODS: National Health and Nutrition Examination Survey (2011-2012) participants who wore wrist-worn accelerometers were included. AHA LE8 scores were calculated based on how many milestones were met. Mortality data were linked from the National Death Index. Logistic regression models were utilized to assess the association between PA levels and mortality, adjusting for demographic, behavioral, and cardiometabolic factors. The area under the curve (AUC) was calculated to evaluate PA's predictive value for mortality. RESULTS: A total 2,918 participants were included. In unadjusted models, higher percentile PA categories were associated with lower all-cause mortality risk (OR: 0.43; 95% CI: 0.36-0.52), with no statistical significance after adjusting for behavioral and metabolic factors (OR: 0.86; 95% CI: 0.43-1.70). Higher LE8 scores correlated with reduced all-cause mortality risk (OR: 0.77; 95% CI: 0.68-0.88 and OR: 0.81; 95% CI: 0.71-0.94) for 50th and 75th percentile PA cutoffs, respectively. AUC analysis using PA demonstrated moderate discriminatory power for all-cause mortality (AUC: 0.746), but not cause-specific mortality. CONCLUSIONS: Higher AHA LE8 scores, with objective measures of PA, are associated with reduced mortality. Objective PA was not associated with all-cause mortality when accounting for behavioral and metabolic health factors.