Higher Daily Step Count Associated with Reduced Risk of All-Cause Mortality

by | Apr 24, 2024 | Cardiovascular Health, Fitness and Exercise, Recent Articles

Written by Taylor Woosley, Science Writer. Observational findings of a population-based cohort study of over 70000 individuals shows that walking 9000 to 10500 steps per day was associated with a substantially lower risk of all-cause mortality and CVD risk. 

fitness and exerciseCardiovascular disease (CVD) is an umbrella term used to describe diseases associated with the heart and blood vessels, such as coronary heart disease (CHD), peripheral arterial disease, and stroke1. Despite a steady decline in CVD mortality over the past decade, cardiovascular health has not improved, with nearly a quarter of CVD-related deaths being preventable by addressing modifiable cardiovascular health behaviors such as insufficient physical activity and diet2. Evidence to date has prompted many to advocate for increasing daily steps as an important part of preventing chronic disease3.

Physical inactivity is one of the major public health issues worldwide, contributing to an estimated 3.2 million deaths annually4. The 2019 American College of Cardiology (ACC) and American Heart Association (AHA) Guideline on the Primary Prevention of CVD recommend at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity or an equivalent combination of aerobic activity per week5. Research shows an optimal dose of 6000 to 8000 steps has been suggested to reduce the risk of all-cause mortality6.

Ahmadi et al. conducted an observational study to investigate if sedentary time modified the optimal and minimal daily steps associated with all-cause mortality and incident CVD risk using a large cohort of UK adults using wrist-worn accelerometers. Subjects from the UK Biobank Study (2006-2010), a prospective cohort of 502629 participants between 40 and 69 years, who underwent physical examinations were included in the analysis. 103684 participants were instructed to wear a Axivity AX3 accelerometer on their dominant wrist for 24 hours/day for 7 days to measure physical activity. Subjects were required to have at least three valid monitoring days to be included in the analysis, with at least one day being a weekend day, and having worn the monitor during sleep periods. Subjects were followed up to October 2021, with deaths obtained through the NHS Central Register.

Primary exposures were daily time spent sedentary (low <10.5 hours/day and high ≥10.5 hours/day) and daily step counts. Covariates included were age, sex, ethnicity, education, smoking status, alcohol consumption, fruit and vegetable consumption, parental history of CVD and cancer, medication use, and accelerometer-measured sleep time. A further analysis was performed with alternate sedentary time groupings with the highest quartile (≥11.5 hours/day) categorized high sedentary time and the lowest three quartiles as low sedentary time.

The analytical sample for mortality included 72174 subjects (average age (SD)=61.1 years; 57.9% female) followed up for an average of 6.9±0.8 years with 1633 deaths. The incident CVD analysis sample included 71441 participants with 6190 events. Median (IQR) total steps and sedentary time were 6222 (4102-9225) steps/day and 10.6 (9.7-11.6) hours/day, respectively and subjects wore the accelerometers for an average of 22.8 hours/day. Significant findings of the study are as follows:

  • Subjects within the high sedentary time level (≥10.5 hours/day), accumulating <4000 steps/day was associated with a crude mortality risk of 5.41% (95% CI 5.32% to 5.50%), whereas accumulating >8000 steps/day was associated with a 3.05% (95% CI 2.96% to 3.13%) crude risk. The corresponding crude risk for subjects within the low sedentary time level (<10.5 hours/day) was 3.74% (95% CI 3.62% to 3.86%) and 2.27% (95% CI 2.24 to 2.30%).
  • For high sedentary time participants, the nadir of the curve was observed to be at 9000 steps/day, corresponding to an HR (95% CI) of 0.61 (0.51 to 0.73), compared with the referent 2200 steps/day. The minimal dose was at 4100 steps/day with an HR of 0.80 (0.74 to 0.87).
  • The dose-response association between steps/day and incident CVD shows a lower risk for the low sedentary time group, for an equivalent steps/day, compared with the high sedentary time group (effect modification p=0.725). The minimal dose was at 4300 steps/day for both high and low sedentary time with corresponding HRs of 0.90 (95% CI 0.86 to 0.94) and 0.86 (95%CI 0.80 to 0.92).

Results of the study shows that walking 9000 to 10500 steps/day was the optimal dose for all-cause mortality across sedentary time groups. Furthermore, the optimal and minimal steps/day association with incident CVD risk between groups was 10000 steps/day and 4500 steps/day, respectively. Study limitations include the inability to rule out potential residual and unmeasured confounding due to the observational study design.

Source: Ahmadi, Matthew N., Leandro FM Rezende, Gerson Ferrari, Borja Del Pozo Cruz, I-Min Lee, and Emmanuel Stamatakis. “Do the associations of daily steps with mortality and incident cardiovascular disease differ by sedentary time levels? A device-based cohort study.” British Journal of Sports Medicine 58, no. 5 (2024): 261-268.

© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.

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Posted April 24, 2024.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

References:

  1. Bell AC, Richards J, Zakrzewski-Fruer JK, Smith LR, Bailey DP. Sedentary Behaviour-A Target for the Prevention and Management of Cardiovascular Disease. Int J Environ Res Public Health. Dec 28 2022;20(1)doi:10.3390/ijerph20010532
  2. Hannan M, Kringle E, Hwang CL, Laddu D. Behavioral Medicine for Sedentary Behavior, Daily Physical Activity, and Exercise to Prevent Cardiovascular Disease: A Review. Curr Atheroscler Rep. Jul 6 2021;23(9):48. doi:10.1007/s11883-021-00948-x
  3. Del Pozo Cruz B, Ahmadi MN, Lee IM, Stamatakis E. Prospective Associations of Daily Step Counts and Intensity With Cancer and Cardiovascular Disease Incidence and Mortality and All-Cause Mortality. JAMA Intern Med. Nov 1 2022;182(11):1139-1148. doi:10.1001/jamainternmed.2022.4000
  4. Inoue K, Tsugawa Y, Mayeda ER, Ritz B. Association of daily step patterns with mortality in US adults. JAMA Network Open. 2023;6(3):e235174-e235174.
  5. Paluch AE, Bajpai S, Ballin M, et al. Prospective Association of Daily Steps With Cardiovascular Disease: A Harmonized Meta-Analysis. Circulation. Jan 10 2023;147(2):122-131. doi:10.1161/circulationaha.122.061288
  6. Del Pozo Cruz B, Ahmadi M, Naismith SL, Stamatakis E. Association of Daily Step Count and Intensity With Incident Dementia in 78 430 Adults Living in the UK. JAMA Neurol. Oct 1 2022;79(10):1059-1063. doi:10.1001/jamaneurol.2022.2672