Interaction between Long-Term Exposure to Fine Particulate Matter and Physical Activity, and Risk of Cardiovascular Disease and Overall Mortality in U.S. Women

Abstract

Background: Increased respiration during physical activity may increase air pollution dose, which may attenuate the benefits of physical activity on cardiovascular disease (CVD) risk and overall mortality. Objectives: We aimed to examine the multiplicative interaction between long-term ambient residential exposure to fine particulate matter ( ) and physical activity in the association with CVD risk and overall mortality. Methods: We followed 104,990 female participants of the U.S.-based prospective Nurses’ Health Study from 1988 to 2008. We used Cox proportional hazards models to assess the independent associations of 24-months moving average residential exposure and physical activity updated every 4 y and the multiplicative interaction of the two on CVD (myocardial infarction and stroke) risk and overall mortality, after adjusting for demographics and CVD risk factors. Results: During 20 years of follow-up, we documented 6,074 incident CVD cases and 9,827 deaths. In fully adjusted models, exposure was associated with modest increased risks of CVD [hazard ratio (HR) for fifth quintile compared to first quintile : 1.09, 95% confidence interval (CI): 0.99, 1.20; ] and overall mortality (HR fifth compared to first quintile: 1.10, 95% CI: 1.02, 1.19; ). Higher overall physical activity was associated with substantially lower risk of CVD [HR fourth quartile, which was equivalent of task (MET)-h/wk, compared to first quartile ( ): 0.61, 95% CI: 0.57, 0.66; ] and overall mortality (HR fourth compared to first quartile: 0.40, 95% CI: 0.37, 0.42; ). We observed no statistically significant interactions between exposure and physical activity (overall, walking, vigorous activity) in association with CVD risk and overall mortality. Discussion: In this study of U.S. women, we observed no multiplicative interaction between long-term exposure and physical activity; higher physical activity was strongly associated with lower CVD risk and overall mortality at all levels of exposure. https://doi.org/10.1289/EHP7402

Effects of air pollution and habitual exercise on the risk of death: a longitudinal cohort study

“…Three previous cohort studies targeting older adults 8,9 and women 10 have been conducted in Hong Kong, 8 Denmark 9 and the US. 10 The Hong Kong study had a similar air pollution level to that of our study, and the studies in Denmark and the US had better air quality. However, the results from our study and all 3 of these studies suggest that habitual exercise is beneficial, even for people living in relatively polluted regions.…”

“…Three cohort studies have explored the relation between air pollution, physical activity and risk of death in Hong Kong, 8 Denmark and the United States, 9 with relatively small sample sizes. 10 Therefore, we sought to investigate the combined effects of habitual exercise and long-term exposure to fine particle matter (PM 2.5 ) on the risk of death from natural causes (i.e., deaths not attributable to accident, suicide or homicide) using a longitudinal cohort of adults in Taiwan, where the annual PM 2.5 concentrations are 1.6 times higher than the WHO-recommended limit. We hypothesized that…”

Ozone Exposure, Outdoor Physical Activity, and Incident Type 2 Diabetes in the SALSA Cohort of Older Mexican Americans

“…On the other hand, a case-control study of 24,053 Hong Kong Chinese reported that among ≥65-y-old never-exercisers (exercised <once=month) the excess risks of allcause mortality were higher [1.75% (95% CI: 0.25%, 3.23%) per 10-lg=m 3 increase in O 3 exposure] compared with those who reported exercising (≥once=month) outdoors during the 10 y before death (Wong et al 2007). Recently, researchers from the U. S.-based prospective Nurses ' Health Study (NHS;n = 104,990, 1998-2008) also found no statistically significant interactions between PM 2:5 exposure and physical activity (overall, walking, vigorous activity) for cardiovascular disease risk and overall mortality (Elliott et al 2020). However, the NHS focused on recreational activities such as jogging, biking, and calisthenics, and these female nurses were on average 63 years of age at the end of follow-up; that is, they were much younger than the SALSA cohort participants.…”

“…However, breathing frequency, tidal volume, and fraction of oral breathing-which are influenced by the intensity of physical activity-will affect particle deposition and gas absorption in the respiratory tract (ICRP 2015), and might attenuate the benefits of physical activity. There are multiple physiological and behavioral mechanisms linking physical activity and air pollution, but the biologic interaction between air pollution exposure and physical activity for health outcomes is not yet well understood (Elliott et al 2020;Tainio et al 2021). Environmental Health Perspectives 097004-7 129(9) September 2021…”

Physical Activity in Polluted Air—Net Benefit or Harm to Cardiovascular Health? A Comprehensive Review

“…There was minor evidence of an interaction between physical activity and PM 2.5 exposure, suggesting that the beneficial health effects of physical activity outweigh the adverse effects of exposure to PM 2.5 . The interaction between PM 2.5 exposure and physical activity, and its association with incident cardiovascular disease risk and overall mortality, was also the subject of a U.S. study of 104,990 female subjects [ 109 ]. As expected, PM 2.5 exposure was associated with increases in cardiovascular disease risk (including myocardial infarction and stroke) and overall mortality, while increased overall physical activity was related to a decreased risk.…”