The Association Between Daily Step Count, Step Frequency and the Risk of Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study Using NHANES Data.

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is a major public health concern globally, and physical activity is considered a modifiable factor in its prevention.

Purpose: This study examined the association between daily step count, step frequency, and the prevalence of chronic obstructive pulmonary disease (COPD) using nationally representative data.

Patients and methods: A cross-sectional analysis was conducted using data from adults aged ≥40 years in the 2003-2006 National Health and Nutrition Examination Survey (NHANES). Participants wore accelerometers for 7 days to measure daily step count and three step frequency indicators: bout cadence, peak 30-minute cadence, and peak 1-minute cadence (steps/minute). Weighted logistic regression was used to assess associations with COPD, adjusting for demographic, behavioral, and health-related covariates. Sensitivity analyses and subgroup analyses were conducted to confirm robustness.

Results: Among 3690 participants (representing ~26.8 million US adults), higher daily step count and step frequency were inversely associated with COPD prevalence. Compared to those taking <4000 steps/day, those taking ≥8000 steps/day had a 63% lower odds of COPD (OR 0.37, 95% CI 0.15-0.91; P for trend <0.001). Higher bout cadence (92.3-153.4 steps/minute) and peak 30-minute cadence (69.8-128.2 steps/minute) were also associated with significantly reduced COPD odds (ORs 0.30 and 0.33, respectively). Combined higher step count and frequency yielded a greater risk reduction. Restricted cubic splines indicated a nonlinear association, and ROC analysis showed moderate discriminatory power (AUC 0.71-0.75). Results remained robust in sensitivity analyses and across subgroups.

Conclusion: In this cross-sectional study of US adults, higher daily step counts and greater walking cadence were associated with a lower prevalence of COPD. These findings support the relevance of step-based metrics in assessing COPD risk, although longitudinal studies are needed to establish causality.