Abstract 13: Associations Between Leisure-Time Physical Activity and Mortality by Sociodemographic Factors in a Nationally Representative Sample of 567,483 US Adults

Introduction: The 2018 Physical Activity Guidelines Advisory Committee Scientific Report called for investigating whether the established health benefits of meeting physical activity guidelines (PAG) differ by sociodemographic factors. Guidelines for adults recommend engaging in muscle-strengthening activities (MSAs; ≥2 days per week) and moderate-to-vigorous aerobic physical activity (MVPA; ≥150 minutes per week at moderate intensity, ≥75 minutes per week at vigorous intensity, or an equivalent combination). Objective: To examine associations between meeting MVPA and MSA guidelines (combined PAG) in leisure time and all-cause and heart disease mortality across sociodemographic factors. Methods: We used nationally representative data on 567,483 adults from the 1998-2018 US National Health Interview Survey (NHIS) and 2019 public-use linked mortality files from the National Death Index. Median follow-up was 9.5 years (range=1-21.8 years). We classified participants into categories (met combined PAG, met MVPA only, met MSA only, met neither) based on reported leisure-time physical activity. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between meeting the combined PAG vs. meeting neither guideline and all-cause and heart disease mortality, overall and stratified by sex (women, men), race and ethnicity (six groups), or education (four levels). Models were adjusted for sociodemographic and health factors. We conducted pairwise comparisons (adjusted for multiple comparisons) to determine if associations differed across sociodemographic factors. Results: Compared to meeting neither PAG, meeting the combined PAG was associated with a reduced mortality risk between 14-36% for all-cause mortality and 25-52% for heart disease mortality across sociodemographic groups. Reductions in mortality risk were larger for some groups compared with others. For example, reduction in all-cause mortality was larger for non-Hispanic White compared with Hispanic or Latino adults (HR=0.66 95% CI: 0.64-0.69 vs. 0.86 0.75-0.99; pairwise p <0.001) and for people with more vs. less education (college or more=0.64 0.60-0.69 vs. less than high school=0.75 0.69-0.82; p <0.001). Reduction in heart disease mortality was larger for women compared with men (0.54 0.48-0.62 vs. 0.66 0.60-0.73; p <0.001). Conclusions: Meeting the guidelines for MVPA and MSA generally provides a substantial reduction in risk of all-cause and heart disease mortality. There may be differences in the magnitude of benefit physical activity provides for health across sociodemographic groups. The reasons for these differences are unclear. Identifying factors contributing to these differences would further address research gaps identified in the 2018 Physical Activity Guidelines Advisory Committee Scientific Report.