Habitual Physical Activity Is Associated with Reduced Risk of Cardiovascular Mortality Regardless of Ambient PM2.5 Exposure

Abstract

BACKGROUND AND AIM: Increased inhalation and deposition of air pollutants during physical activity (PA) may attenuate the beneficial effects PA on cardiovascular disease. We thus examined the interaction between chronic exposure to fine particle matter (PM2.5) and habitual PA in the association with Cardiovascular (CVD) mortality in Taiwan. METHODS: We included a total of 384,128 adults (aged 18 years old or above) with 842,384 medical examinations from 2001 to 2016. All participants were followed up until May 31, 2019. The vital status were retrieved from the National Death Registry of Taiwan. The satellite-based spatiotemporal model was selected to estimate ambient PM2.5. A standard self-administered questionnaire was used to evaluate the information of habitual PA. The Cox regression with time-dependent covariates was adopted to evaluate the interaction between chronic exposure to PM2.5 and habitual PA on CVD mortality. RESULTS:The CVD mortality risk was positively associated with chronic exposure to PM2.5 and inversely associated with habitual PA. The inverse associations of habitual PA with CVD mortality were not modified by chronic exposure to PM2.5. Compared to individuals with inactive-low-PA and high-PM2.5, those with high-PA and low-PM2.5 exhibited a 60% lower risk of cardiovascular mortality [95% confidence interval (CI): 52%-67%]. CONCLUSIONS:Increased PA and reduced PM2.5 exposure are associated with lower risk of CVD mortality. Exposure to high levels of PM2.5 did not modify the benefits of habitual PA on CVD mortality. KEYWORDS: Particulate matter, Long-term exposure, cardiovascular mortality