Acute effect of ambient fine particulate matter on heart rate variability: an updated systematic review and meta-analysis of panel studies

BACKGROUND@#Decreased heart rate variability (HRV) is a predictor of autonomic system dysfunction, and is considered as a potential mechanism of increased risk of cardiovascular disease (CVD) induced by exposure to particulate matter less than 2.5 μm in diameter (PM@*METHODS@#An updated systematic review and meta-analysis of panel studies till November 1, 2019 was conducted to evaluate the acute effect of exposure to ambient PM@*RESULTS@#A total of 33 panel studies were included in our meta-analysis, with 16 studies conducted in North America, 12 studies in Asia, and 5 studies in Europe. The pooled results showed a 10 μg/m@*CONCLUSION@#Short-term exposure to PM