European Primary Care Cardiovascular Society

Even at high air pollution, physical activity pays off for MI prevention

Effects of Leisure-Time and Transport-Related Physical Activities on the Risk of Incident and Recurrent Myocardial Infarction and Interaction With Traffic-Related Air Pollution: A Cohort Study

Literature - Kubesch NJ, Therming Jørgensen J, Hoffmann B, et al. - J Am Heart Assoc. 2018;7:e009554

Introduction and methods

Physical activity reduces the risk of cardiovascular (CV) disease through several mechanisms, including improvements in inflammatory status, hemostatic factors, insulin sensitivity, and blood lipids [1]. Outdoor air pollution, on the other hand, leads to worsening of inflammatory status and oxidative stress, and is therefore a CV risk factor [2]. Physical activity in areas with air pollution may increase exposure to pollutants due to exercise-induced higher minute ventilation, leading to higher deposition of the inhaled particles in the lungs [3]. However, it is not known whether the benefit of physical activity on CV risk is reduced by exposure to air pollution.

This analysis of the Danish Diet, Cancer, and Health cohort [4], evaluated the effects of physical activity on the risk of incident and recurrent myocardial infarction (MI) in middle-aged men and women, and assessed whether air pollution modifies the association between physical activity and MI.

The Danish Diet, Cancer, and Health cohort included 57,053 individuals with or without a history of MI, aged 50-64 years, between 1993 and 1997. Individuals with a history of cancer and missing data of interest were excluded for this analysis, leaving a study sample of 51,868 participants. Physical activity (sports, cycling, walking, and gardening) was reported in hours per week (h/wk) using a validated questionnaire [5], and NO2 exposure was estimated for the residential addresses of participants using the Danish AirGIS dispersion modeling system [6], and classified into low (<14.3 lg/m3), medium (≥14.3–21.0 lg/m3), and high (≥21.0 lg/m3) exposure.

Main results


Physical activity, even at moderate levels, reduces the risk of incident and recurrent MI, independently of the exposure to NO2. These results suggest that the long-term benefits of physical activity in primary and secondary MI prevention outweigh the risks associated with exposure to air pollution.


Show references

Find this article online at JAHA

Share this page with your colleagues and friends: