摘要目的:探索短期环境空气污染物暴露与动脉僵硬度相关指标之间的关联，并探索肥胖是否对上述关联存在效应修饰作用。方法:基于北京房山家系队列基线资料开展分析。采用研究对象参与调查当天的空气污染物浓度的24 h均值作为污染指标，采用广义加性高斯模型估计短期各项空气污染物（PM 2.5、PM 10、SO 2、NO 2、CO）暴露与颈总动脉内膜厚度（CIMT）、脉搏波传导速度（BAPWV）、脉压（PP）和踝肱指数（ABI）的关联。将各项空气污染物和BMI、腰臀比的交叉项纳入模型以检验交互作用，并开展分层分析进一步探索其对短期各项空气污染物暴露与CIMT、BAPWV、PP、ABI关联的影响。 结果:共纳入4 211名研究对象进行分析。研究对象年龄为（58.9±8.7）岁，其中2 268名（53.9%）为女性。模型调整社会人口学、生活行为方式、用药史等混杂因素。结果显示，PM 2.5（ β=2.912×10 -4，95% CI：1.424×10 -4~4.400×10 -4， P<0.001）、CO（ β=0.027，95% CI：0.011~0.043， P<0.001）、SO 2（ β=2.070×10 -3，95% CI：7.060×10 -4~3.430×10 -3， P=0.003）、NO 2（ β=3.650×10 -4，95% CI：2.340×10 -5~7.060×10 -4， P=0.036）4种污染浓度增加与CIMT水平升高有关。PM 10（ β=0.018，95% CI：0.002~0.033， P=0.028）浓度增加与PP水平升高有关。研究未发现短期空气污染物暴露与ABI、BAPWV水平存在关联。腰臀比对短期PM 2.5（交互作用 P=0.015）、NO 2（交互作用 P=0.008）、CO（交互作用 P=0.044）暴露与CIMT的关联存在效应修饰作用；对短期PM 2.5（交互作用 P=0.002）、NO 2（交互作用 P=0.010）、CO（交互作用 P=0.029）、PM 10（交互作用 P<0.001）暴露与PP的关联存在效应修饰作用，腰臀比较低的人群中空气污染物浓度升高相关的CIMT、PP升高更显著。 结论:短期暴露于多种空气污染物与CIMT、PP等动脉僵硬度指标存在关联，腰臀比对此关联存在效应修饰作用，较低腰臀比可能会增强空气污染物暴露与指标的关联。

abstractsObjective:To assess the association between short-term ambient air pollution exposure and arterial stiffness and whether obesity modifies these associations.Methods:A cross-sectional study was conducted based on Fangshan family cohort in Beijing. The 24 hours average air pollutant levels on the day cohort participants took baseline survey were calculated as short-term air pollution. A generalized additive model (GAM) with Gaussian links was used to estimate changes in typical carotid artery intima-media thickness (CIMT), brachial-ankle pulse wave velocity (BAPWV), pulse pressure (PP) and ankle-branchial index (ABI) after short-term exposure to each air pollution (PM 2.5, PM 10, SO 2, NO 2, CO). The cross-product terms of each air pollution, body mass index (BMI), and waist-to-hip ratio were included in the GAM model to test the interaction. Further, they conducted a stratified analysis to test their effects on the relationship between short-term exposure to each air pollution and the arterial stiffness indicators. Results:A total of 4 211 individuals were included in the analysis. Individuals' age was (58.9±8.7) years, of which 2 268 (53.9%) were female. Several covariates, including sociodemographic factors, lifestyle behaviors, and history of drugs, were included in the analysis. The results of the GAM analysis showed that an increase in PM 2.5 ( β=2.912×10 -4, 95% CI: 1.424×10 -4-4.400×10 -4, P<0.001), CO ( β=0.027, 95% CI: 0.011-0.043, P<0.001), SO 2 ( β=2.070×10 -3, 95% CI: 7.060×10 -4-3.430×10 -3, P=0.003), and NO 2 ( β=3.650×10 -4, 95% CI: 2.340×10 -5-7.060×10 -4, P=0.036) were associated with an increase in CIMT, while an increase in PM 10 ( β=0.018, 95% CI: 0.002-0.033, P=0.028) was associated with an increase in PP in the study population. Besides, the waist-to-hip ratio had an effect-modification on the correlation of short-term exposure of PM 2.5 (interaction P=0.015), NO 2 (interaction P=0.008), and CO (interaction P=0.044) with CIMT, and the correlation between short-term exposure of PM 2.5 (interaction P=0.002), NO 2 (interaction P=0.010), CO (interaction P=0.029), PM 10 (interaction P<0.001) with PP. The significant association between CIMT, PP, and air pollution concentrations was more visible in people with lower waist-to-hip ratios. Conclusions:Short-term ambient air pollution exposure was associated with arterial stiffness indicators, and there was an effect modification of waist-to-hip ratio on these associations, and lower waist-to-hip ratios may enhance the association between air pollution exposure and indicators.