Environment Influences Exercise Capacity of Patients With COPD, Study Says

The physical activity and exercise capacity of people with chronic obstructive pulmonary disease (COPD) appear to be related to population density, pedestrian street length, slope of terrain, and exposure to nitrogen dioxide (NO₂) in the vicinity of their homes, according to a recent study.

The researchers said their findings lend support to the idea that urban and transportation planning policies should take into account the needs of patients with chronic disease.

The study, recently published in Environmental Research, was conducted in Spain with 405 patients with mild to very severe COPD. Researchers sought to estimate the association between environmental factors, objective physical activity, functional exercise capacity, and the difficulty of physical activity.

The patients were 85% male, had a mean (SD) age of 69 (9) years, and on average walked 7524 steps per day. Their physical activity was measured with the Dynaport MoveMonitor, the difficulty of physical activity was measured via a patient questionnaire, and exercise capacity was measured using the 6-minute walk test.

To estimate urban environmental factors that each patient faced, the researchers used geocoded residential addresses to determine census tract population density, length of pedestrian streets in the neighborhood, slope of terrain, and annual exposure to road traffic noise, NO₂ (an indicator of traffic-related air pollution), and particulate matter (PM_2.5).

Results showed the following:

• Higher population density was associated with fewer steps taken by patients, more sedentary time, and worse exercise capacity (with a stronger link being found with concurrent depression symptoms).
• Longer pedestrian street lengths were linked with more steps and less sedentary time.
• Steeper slope (ie, hilly streets) was associated with greater exercise capacity.
• Higher long-term exposure to NO₂ was linked with more sedentary time and more difficulty with physical activity.

High population density had a stronger negative effect on patients with both COPD and depression. Researchers speculated this might stem from feeling embarrassed or self-conscious due to visible symptoms such as shortness of breath and difficulty walking.

No links were found between PM_2.5 and noise exposure with physical activity or exercise capacity.

The researchers concluded that these neighborhood environmental factors should be considered in clinical contacts with patients and when developing urban and transport planning policies aimed at promoting physical activity in patients with a chronic disease. Research on the urban environment has often ignored this population, which currently accounts for approximately 35% of urban dwellers in Europe.

Reference

Koreny M, Arbillaga-Etxarrid A, Bosch de Basea M, et al. Urban environment and physical activity and capacity in patients with chronic obstructive pulmonary disease. Environ Res. Published online July 22, 2022. doi:10.1016/j.envres.2022.113956