Prospective Association of Daily Steps With Cardiovascular Disease: A Harmonized Meta-Analysis

Abstract

Background: Taking fewer than the widely promoted "10 000 steps per day" has recently been associated with lower risk of all-cause mortality. The relationship of steps and cardiovascular disease (CVD) risk remains poorly described. A meta-analysis examining the dose-response relationship between steps per day and CVD can help inform clinical and public health guidelines.

Methods: Eight prospective studies (20 152 adults [ie, ≥18 years of age]) were included with device-measured steps and participants followed for CVD events. Studies quantified steps per day and CVD events were defined as fatal and nonfatal coronary heart disease, stroke, and heart failure. Cox proportional hazards regression analyses were completed using study-specific quartiles and hazard ratios (HR) and 95% CI were meta-analyzed with inverse-variance-weighted random effects models.

Results: The mean age of participants was 63.2±12.4 years and 52% were women. The mean follow-up was 6.2 years (123 209 person-years), with a total of 1523 CVD events (12.4 per 1000 participant-years) reported. There was a significant difference in the association of steps per day and CVD between older (ie, ≥60 years of age) and younger adults (ie, <60 years of age). For older adults, the HR for quartile 2 was 0.80 (95% CI, 0.69 to 0.93), 0.62 for quartile 3 (95% CI, 0.52 to 0.74), and 0.51 for quartile 4 (95% CI, 0.41 to 0.63) compared with the lowest quartile. For younger adults, the HR for quartile 2 was 0.79 (95% CI, 0.46 to 1.35), 0.90 for quartile 3 (95% CI, 0.64 to 1.25), and 0.95 for quartile 4 (95% CI, 0.61 to 1.48) compared with the lowest quartile. Restricted cubic splines demonstrated a nonlinear association whereby more steps were associated with decreased risk of CVD among older adults.

Conclusions: For older adults, taking more daily steps was associated with a progressively decreased risk of CVD. Monitoring and promoting steps per day is a simple metric for clinician-patient communication and population health to reduce the risk of CVD.

Keywords: cardiovascular disease; exercise; public health; risk reduction behavior.

Figure 1.. Association of Steps per Day and CVD Events Stratified by Age and Sex.

Hazard Ratio and 95% Confidence Intervals [HR (95%CI)]. Model 1 is adjusted for age and sex (if applicable). Model 2: Model 1 + device wear time, race/ethnicity (if applicable), education or income, body mass index, and plus study-specific variables for lifestyle (smoking, alcohol), hypertension, diabetes, dyslipidemia, chronic conditions, and general health status. I² values were considered low (<25%), moderate (25%-75%), or high (>75%). The x-axis is a log scale. *p<0.05 for subgroup difference

Figure 2.. Association of Steps per Day with CVD events for (a) older adults ≥ 60 years and (b) younger adults < 60 year.

Restricted cubic splines of hazard ratios of steps/d with CVD events. Knots set at 10th, 50th, and 90th, percentile of steps/d. Reference set at median of lowest quartile (2,000 for older adults, 3,000 for younger adults).Hazard Ratios are indicated by solid lines and 95% Confidence Intervals are indicated by dotted lines. Model 1 adjusted for age and sex (if applicable). Model 2: Model 1 + device wear time, race/ethnicity (if applicable), education or income, body mass index, lifestyle (smoking, alcohol), hypertension, diabetes, dyslipidemia, and self-rated health. The y-axis is a log scale.