Is daily step count and the intensity of steps associated with the risk of premature mortality?
This study found that a greater number of daily steps was significantly associated with lower all-cause mortality. Step intensity was not significantly associated with mortality after controlling for total daily steps. (Level of Evidence = 1b)
The investigators reviewed data obtained from the National Health and Nutrition Examination Survey focusing on participants who were asked to wear a hip accelerometer during waking hours for a seven-day period from 2003 to 2006. Individuals with at least one day of valid wear (at least 10 hours) were included. Additional data collection included demographic information (e.g., age, sex, education), smoking status, alcohol intake, and diagnoses of chronic medical conditions (e.g., diabetes mellitus, heart disease, stroke, cancer, chronic bronchitis). In addition to counting steps, step intensity was estimated based on extended bouts of stepping and peak one-minute and 30-minute cadences. Assessments of mortality occurred via the U.S. National Death Index.
Participants (N = 4,840) took a mean of 9,124 steps per day. The incidence of all-cause mortality was 76.7 per 1,000 person-years for individuals who took fewer than 4,000 steps per day; 21.4 per 1,000 person-years for individuals who took 4,000 to 7,999 steps per day; 6.9 per 1,000 person-years for individuals who took 8,000 to 11,999 steps per day; and 4.8 per 1,000 person-years for individuals who took at least 12,000 steps per day. After controlling for total steps per day, greater step intensity was not significantly associated with lower mortality.
Study design: Cohort (prospective)
Funding source: Foundation
Reference:Saint-MauricePFTroianoRPBassettDRJret alAssociation of daily step count and step intensity with mortality among US adults. JAMA2020;323(12):1151–1160.