The impact of particulate matter air pollution (PM2.5) on atherosclerosis in modernizing China: a report from the CATHAY study

Abstract

Background Air pollution has been associated with an increase in cardiovascular diseases incidence. To evaluate whether air pollution can accelerate atherogenic processes, we assessed the effects of air pollution on important surrogate markers of atherosclerosis [brachial flow-mediated dilation (FMD) and carotid intima-media thickness (IMT)]. Methods A total of 1656 Han Chinese (mean age 46.0 + 11.2 years; male 47%) in Hong Kong, Macau, Pun Yu, Yu County and the 3-Gorges Territories (Yangtze River) were studied between 1996 and 2007 [Chinese Atherosclerosis in the Aged and Young Project (the CATHAY Study)]. Cardiovascular risk profiles were evaluated. Particulate matter with an aerodynamic diameter <2.5 µm (PM2.5) parameters were computed from satellite sensors. Brachial FMD and carotid IMT were measured by ultrasound. Results Health parameters [age, gender, body mass index, waist : hip ratio (WHR) and glucose)] were similar in lowest and highest PM2.5 exposure tertiles, systolic and diastolic blood pressures and triglycerides were higher (P < 0.001) and low-density cholesterol (LDL-C) was lower in the top PM2.5 tertile (P < 0.001). Brachial FMD [7.84 ± 1.77, 95% confidence interval (CI) 7.59–8.10%, vs 8.50 ± 2.52, 95% CI 8.23–8.77%, P < 0.0001) was significantly lower and carotid IMT (0.68 ± 0.13 mm, 95% CI 0.67–0.69 mm vs 0.63 mm ± 0.15 mm 95% CI 0.62–0.64 mm; P < 0.0001) was significantly thicker in the top PM2.5 tertile compared with the lowest tertile. On multiple regression, FMD was inversely related to PM2.5 (beta = 0.134, P = 0.015) independent of gender, age and blood pressure (model R2 = 0.156, F-value = 7.6, P < 0.0001). Carotid IMT was significantly correlated with PM2.5 exposure (beta = 0.381, P < 0.0001) independent of age, location, gender, WHR, blood pressure and LDL-C (model R2 = 0.408, F-value = 51.4, P-value <0.0001). Conclusions Air pollution is strongly associated with markers of early atherosclerosis, suggesting a potential target for preventive intervention.

Individual exposure to ambient PM2.5 and hospital admissions for COPD in 110 hospitals: a case-crossover study in Guangzhou, China

“…The differences in the effects of PM 2.5 on hospital admissions for COPD by sex were statistically significant in our study, which was in accordance with prior studies (Lin et al 2018). A higher effect was observed in males, and the difference between gender may be due to lifestyle behaviors (tobacco and alcohol consumption, exercise, and diet) (Xie et al 2019). As for the disparities by age, we found that the effects of PM 2.5 on hospitalizations were statistically significant in individuals ≥65 years of age for COPD, while non-significant results were observed in those <65 years.…”

“…Such finding was also observed in a study which explored the association between PM 2.5 and hospital admissions for acute exacerbation of COPD in southwestern Taiwan, China (Hwang et al 2017). A study in Hefei, China, claimed that the effect of PM 2.5 on COPD hospitalization differed by age, although the statistical significance of the difference was not examined (Xie et al 2019). Regarding the disparities in the associations of PM 2.5 with hospitalizations for COPD by occupational class and marital status, a relatively small sample size for some subgroups in the present study may account for the lack of statistical power to detect significant effects.…”

“…Measurements of air pollutant concentrations obtained from monitoring stations can capture the temporal variation of the average exposure level. However, using the average measurements from a limited number of monitoring stations cannot fully reflect the spatial variation in exposure level of subjects which may lead to bias in the estimates of associations between air pollutants and health outcomes due to the measurement error of exposure (Hwang et al 2017;Liu et al 2017;Tian et al 2018;Xie et al 2019;Zuo et al 2019). On this issue, an accurate proxy of individual exposure using satellite-based PM 2.5 with high resolution is crucial when investigating the health effects of air pollution.…”

“…We previously proposed a method for a high-coverage and accurate estimation of daily PM 2.5 at a 1-km resolution in mainland China based on the satellite data of atmospheric aerosol optical depth (AOD) by solving the problem of high missing rate, which is usually ignored in previous studies and leads to inaccurate estimation of PM 2.5 (Chen et al 2020). The 1-km estimates of PM 2.5 which can be matched with the residential addresses are expected to be a more precise proxy for the exposure level of PM 2.5 for the subjects involved in studies on the health effect of air pollution, and the effect estimates tend to be more reliable (Hennig et al 2020;Wong et al 2015;Woo et al 2020). Several cohort studies have applied satellitederived exposure data to quantify the long-term effects of PM 2.5 on health outcomes, with the data of addresses of subjects (Danesh et al 2019;Guo et al 2018;Lin et al 2018).…”

Independent Effects of Metabolic Syndrome and Air Pollution (PM2.5) on Atherosclerosis in Modernizing China

“…Both flowmediated dilation (FMD) and carotid Intima-media thickness (IMT) have been shown to be reliable and reproducible atherosclerotic surrogates, significantly correlated with endothelial physiology, severity and extent of coronary artery disease, and predictive of subsequent stroke and coronary events [9,10]. PM2.5 air pollution exposure has been associated with arterial endothelial dysfunction, intima-media thickening as well as computer tomography-derived coronary calcification [10][11][12][13][14]. MS is highly prevalent in the USA and most western countries (22-43.3%) [15,16].…”