Association of Daily Step Patterns with Mortality in US Adults

Abstract

IMPORTANCE Previous studies have shown that individuals who regularly walk, particularly 8000 daily steps or more, experience lower mortality. However, little is known about the health benefits of walking intensively only a few days a week. OBJECTIVE To evaluate the dose-response association between the number of days an individual takes 8000 steps or more and mortality among US adults. DESIGN, SETTING, AND PARTICIPANTS This cohort study evaluated a representative sample of participants aged 20 years or older in the National Health and Nutrition Examination Surveys 2005- 2006 who wore an accelerometer for 1 week and their mortality data through December 31, 2019. Data were analyzed from April 1, 2022, to January 31, 2023. EXPOSURES Participants were grouped by the number of days per week they took 8000 steps or more (0 days, 1-2 days, and 3-7 days). MAIN OUTCOMES AND MEASURES Multivariable ordinary least squares regression models were used to estimate adjusted risk differences (aRDs) for all-cause and cardiovascular mortality during the 10-year follow-up, adjusting for potential confounders (eg, age, sex, race and ethnicity, insurance status, marital status, smoking, comorbidities, and average daily step counts). RESULTS Among 3101 participants (mean [SD] age, 50.5 [18.4] years; 1583 [51.0%] women and 1518 [49.0%] men; 666 [21.5%] Black, 734 [23.7%] Hispanic, 1579 [50.9%] White, and 122 [3.9%] other race and ethnicity), 632 (20.4%) did not take 8000 steps or more any day of the week, 532 (17.2%) took 8000 steps or more 1 to 2 days per week, and 1937 (62.5%) took 8000 steps or more 3 to 7 days per week. Over the 10-year follow-up, all-cause and cardiovascular deaths occurred in 439 (14.2%) and 148 (5.3%) participants, respectively. Compared with participants who walked 8000 steps or more 0 days perweek, all-cause mortality riskwas lower among those who took 8000 steps or more 1 to 2 days perweek (aRD,-14.9%; 95%CI-18.8% to-10.9%) and 3 to 7 days perweek (aRD, -16.5%; 95%CI,-20.4%to-12.5%). The dose-response association for both all-cause and cardiovascular mortality riskwas curvilinear; the protective association plateaued at 3 days perweek. Different thresholds for the number of daily steps between 6000 and 10 000 yielded similar results. CONCLUSIONS AND RELEVANCE In this cohort study of US adults, the number of days per week taking 8000 steps or more was associated with a lower risk of all-cause and cardiovascular mortality in a curvilinear fashion. These findings suggest that individuals may receive substantial health benefits by walking just a couple days a week.