Short-term effects of air pollution on blood pressure

You-Jung Choi,Hae-Young Lee,Si-Hyuck Kang,Ok-Jin Kim,Sun-Hwa Kim,Sun-Young Kim,Tae-Jin Youn,Chang-Hwan Yoon,Cheol-Ho Kim,In-Ho Chae

doi:10.1038/s41598-019-56413-y

Abstract

Elevated blood pressure (BP) has been proposed as a possible pathophysiological mechanism linking exposure to ambient air pollution and the increased risk of cardiovascular mortality and morbidity. In this study, we investigated the hourly relationship between ambient air pollutants and BP. BP measurements were extracted from the electronic health record database of the Seoul National University Bundang Hospital from February 2015 to June 2017. A total of 98,577 individual BP measurements were matched to the hourly levels of air pollutants. A generalized additive model was constructed for hour lags of 0–8 of air pollutants adjusting for age, sex, meteorological variables, and time trend. Systolic BP was shown to be significantly lower at 2–4 hours and 3–5 hours after increased levels of SO2 and CO, respectively (0.24 mmHg and 0.26 mmHg for an interquartile range, respectively). In contrast, O3 and NO2 were associated with significantly increased systolic BP at 3–5 lag hours and at 0–2 lag hours, respectively. BP elevation in association with O3 and NO2 was shown to be significantly greater in hypertensive patients than normotensive subjects. Our findings suggest that short-term exposure to air pollution may be associated with elevated BP.

Highlights

Elevated blood pressure (BP) has been proposed as a possible pathophysiological mechanism linking exposure to ambient air pollution and the increased risk of cardiovascular mortality and morbidity
BP was shown to be elevated within several hours after exposure to increased levels of O3 and NO2, and to be depressed after exposure to SO2 and carbon monoxide (CO)
The increase in systolic BP related with short-term exposure to O3 and NO2 was significantly greater in hypertensive than in normotensive subjects

Summary

Introduction

Elevated blood pressure (BP) has been proposed as a possible pathophysiological mechanism linking exposure to ambient air pollution and the increased risk of cardiovascular mortality and morbidity. Our findings suggest that short-term exposure to air pollution may be associated with elevated BP. The Global Burden of Disease study ranked ambient air pollution as sixth among other risk factors in terms of attributable disability-adjusted life-year[12]. Recent studies have suggested that air pollution leads to elevated BP, and this may be an important mechanism defining the link between ambient air pollution and cardiovascular mortality and morbidity[13,14]. Observational studies and meta-analyses have indicated that short-term exposure to air pollution, including PM2.5, increases BP and the frequency of emergency visits for hypertension[17,18,19]. Long-term exposure to PM2.5 and nitrogen dioxide (NO2) has been associated with higher BP and development of hypertension[19,20]

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