Activity And Premature Mortality By Sex: Coronary Artery Risk Development In Young Adults (CARDIA) Study

Evidence supports an inverse association of physical activity (PA) with all-cause mortality and differences by sex; however, most studies are conducted among older adults. PURPOSE: To examine sex specific associations of accelerometer-determined time spent in sedentary behavior (SB), light intensity PA (LIPA), moderate to vigorous intensity PA (MVPA), and total counts during the young adult to midlife transition (ages 38 to 50 years) with all-cause mortality (follow-up ~15 years). METHODS: We analyzed a subsample of adults from CARDIA who wore a hip device ≥4 of 7 days, for ≥10 hrs during the Year 20 follow-up exam (2005-06; baseline for analysis). SB, LIPA, and MVPA (min·d-1) and total counts were analyzed continuously and by quartiles. Participants were followed for mortality through August 2020. Multivariable Cox proportional hazard models stratified by sex were used to estimate the hazard ratio (HR) of mortality across behaviors, adjusting for age, race, center, education (≤ or > high school), body mass index, financial strain (somewhat to very hard or not very hard), smoking status (former/current or never), and the other behaviors. RESULTS: Among 2,292 with adherent device data (mean age = 45.3; 41.6% Black; 58.0% women), there were 114 deaths (5.0%) over 33,545 person-years of follow-up. Mortality was highest among men (6.1%) and those least active: Q4 for SB (5.6%) and Q1 for MVPA (7.8%). For women, there was a lower risk for mortality for LIPA in Q3 (HR = 0.37, 95% CI: 0.16, 0.89) and Q4 (HR = 0.30, 95% CI: 0.11, 0.81) compared to Q1 and for total counts in Q2 (HR = 0.37, 95% CI: 0.17, 0.80) and Q3 (HR = 0.39, 95% CI: 0.18, 0.89) compared to Q1. No significant associations were found for men. Continuous cubic spline HR show U-shape associations (Figure). CONCLUSIONS: In this midlife cohort, more LIPA and total counts were associated with lower risk of premature mortality in women. Ongoing surveillance will provide additional clarify as outcomes accumulate during older adulthood.