Prospective Associations of Daily Step Counts and Intensity With Cancer and Cardiovascular Disease Incidence and Mortality and All-Cause Mortality

Abstract

Importance: Recommendations for the number of steps per day may be easier to enact for some people than the current time- and intensity-based physical activity guidelines, but the evidence to support steps-based goals is limited.

Objective: To describe the associations of step count and intensity with all-cause mortality and cancer and cardiovascular disease (CVD) incidence and mortality.

Design, setting, and participants: This population-based prospective cohort study used data from the UK Biobank for 2013 to 2015 (median follow-up, 7 years) and included adults 40 to 79 years old in England, Scotland, and Wales. Participants were invited by email to partake in an accelerometer study. Registry-based morbidity and mortality were ascertained through October 2021. Data analyses were performed during March 2022.

Exposures: Baseline wrist accelerometer-measured daily step count and established cadence-based step intensity measures (steps/min): incidental steps, (<40 steps/min), purposeful steps (≥40 steps/min); and peak-30 cadence (average steps/min for the 30 highest, but not necessarily consecutive, min/d).

Main outcomes and measures: All-cause mortality and primary and secondary CVD or cancer mortality and incidence diagnosis. For cancer, analyses were restricted to a composite cancer outcome of 13 sites that have a known association with reduced physical activity. Cox restricted cubic spline regression models were used to assess the dose-response associations. The linear mean rate of change (MRC) in the log-relative hazard ratio for each outcome per 2000 daily step increments were also estimated.

Results: The study population of 78 500 individuals (mean [SD] age, 61 [8] years; 43 418 [55%] females; 75 874 [97%] White individuals) was followed for a median of 7 years during which 1325 participants died of cancer and 664 of CVD (total deaths 2179). There were 10 245 incident CVD events and 2813 cancer incident events during the observation period. More daily steps were associated with a lower risk of all-cause (MRC, -0.08; 95% CI, -0.11 to -0.06), CVD (MRC, -0.10; 95% CI, -0.15 to -0.06), and cancer mortality (MRC, 95% CI, -0.11; -0.15 to -0.06) for up to approximately 10 000 steps. Similarly, accruing more daily steps was associated with lower incident disease. Peak-30 cadence was consistently associated with lower risks across all outcomes, beyond the benefit of total daily steps.

Conclusions and relevance: The findings of this population-based prospective cohort study of 78 500 individuals suggest that up to 10 000 steps per day may be associated with a lower risk of mortality and cancer and CVD incidence. Steps performed at a higher cadence may be associated with additional risk reduction, particularly for incident disease.

Figure 1.. Dose-Response Associations Between Primary Exposures and All-Cause Mortality

Hazard ratios and associated 95% CIs adjusted for age, sex, race, education, Townsend Deprivation Index, smoking, alcohol use, fruit and vegetable consumption, family history of cancer and CVD, medication use (cholesterol, insulin, hypertension), accelerometer-measured sleep, and wear accelerometer days. For incidental steps, models were further adjusted for purposeful steps (and vice versa). Dose-response associations were assessed with restricted cubic splines with knots at 10th, 50th, and 90th percentiles of the distribution of the exposure of interest. Darker colors in the lower bars represent a higher sample clustering. Shaded areas represent 95% CIs. CVD indicates cardiovascular disease; total steps/d, median number of steps per day across valid days; incidental steps, total daily steps at 1-39 steps/min; purposeful steps, total daily steps at ≥40 steps/min; peak 30-min cadence, average steps/min recorded for the 30 highest, but not necessarily consecutive, min/day.

Figure 2.. Dose-Response Association Between Primary Exposures and CVD Mortality

Hazard ratios and associated 95% CIs adjusted for age, sex, race, education, Townsend Deprivation Index, smoking, alcohol use, fruit and vegetable consumption, family history of cancer and CVD, medication use (cholesterol, insulin, hypertension), accelerometer-measured sleep, and wear accelerometer days. For incidental steps, models were further adjusted for purposeful steps (and vice versa). Dose-response associations were assessed with restricted cubic splines with knots at 10th, 50th, and 90th percentiles of the distribution of the exposure of interest. Darker colors in the lower bars represent a higher sample clustering. Shaded areas represent 95% CIs. CVD indicates cardiovascular disease; total steps/d, median number of steps per day across valid days; incidental steps, total daily steps at 1-39 steps/min; purposeful steps, total daily steps at ≥40 steps/min; peak 30-min cadence, average steps/min recorded for the 30 highest, but not necessarily consecutive, min/day.

Figure 3.. Dose-Response Association Between Primary Exposures and Cancer Composite of 13 Sites With a Known Relationship With Low Physical Activity

Hazard ratios and associated 95% CIs adjusted for age, sex, race, education, Townsend Deprivation Index, smoking, alcohol use, fruit and vegetable consumption, family history of cancer and CVD, medication use (cholesterol, insulin, hypertension), accelerometer-measured sleep, and wear accelerometer days. For incidental steps, models were further adjusted for purposeful steps (and vice versa). Dose-response associations were assessed with restricted cubic splines with knots at 10th, 50th, and 90th percentiles of the distribution of the exposure of interest. Darker colors in the lower bars represent a higher sample clustering. Shaded areas represent 95% CIs. CVD indicates cardiovascular disease; total steps/d, median number of steps per day across valid days; incidental steps, total daily steps at 1-39 steps/min; purposeful steps, total daily steps at ≥40 steps/min; peak 30-min cadence, average steps/min recorded for the 30 highest, but not necessarily consecutive, min/day.