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 per week, all-cause mortality risk was lower among those who took 8000 steps or more 1 to 2 days per week (aRD, -14.9%; 95% CI -18.8% to -10.9%) and 3 to 7 days per week (aRD, -16.5%; 95% CI, -20.4% to -12.5%). The dose-response association for both all-cause and cardiovascular mortality risk was curvilinear; the protective association plateaued at 3 days per week. 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.

Figure 1.. Number of Days Taking 8000 Steps or More Throughout the Week and 10-Year Risk of All-Cause and Cardiovascular Mortality With and Without Adjusting for Average Daily Step Counts

Solid lines indicate the point estimate; dash lines, 95% CIs. Model 1 included age; sex; race and ethnicity; insurance status; marital status; smoking; body mass index; estimated glomerular filtration rate; statin use; and history of diabetes, hypertension, cardiovascular disease (CVD), cancer, and emphysema. Model 2 included average daily step counts in addition to the covariates in model 1. RD indicates risk difference.

Figure 2.. Subgroup Analyses for the Association Between the Number of Days Taking 8000 Steps or More Throughout the Week and 10-Year All-Cause Mortality Risk by Age and Sex

Based on the regression models, adjusted probability for all-cause mortality in each exposure status was estimated, fixing individual characteristics at each level of the categories and averaging over the national sample. The model adjusted for age; sex; race and ethnicity; insurance status; marital status; smoking; body mass index; estimated glomerular filtration rate; statin use; history of diabetes, hypertension, cardiovascular disease, cancer, and emphysema; and average daily step counts.