【摘要】 [背景]二氧化氮（NO₂）是主要的大气污染物之一，我国大气NO₂污染水平逐年改善，但仍处于较高水平，威胁人群健康。[目的]探讨大气NO₂短期暴露对正常体重和肥胖年轻个体凝血功能相关指标的影响及气温的修饰作用。[方法]采用平行对照定组研究设计，招募53名正常体重和44名肥胖年轻个体作为研究对象，进行三次前瞻性随访。选择距离研究对象住所最近的固定监测站数据，结合时间活动日志与渗透系数计算研究对象每次随访前一周的污染物个体暴露水平，从中国气象数据服务中心获取气温数据。每次随访时，采集研究对象空腹静脉血以检测血小板（PLT）计数、平均血小板体积（MPV）、可溶性CD40配体（s CD40L）、可溶性P-选择素（s P-selectin）、血小板聚集率（PAg T）和纤溶酶原激活物抑制剂-1（PAI-1）等。采用线性混合效应模型分析大气NO₂短期暴露与不同体重年轻个体凝血功能相关指标间的关联，采用分层分析探讨气温的修饰作用。[结果]本研究中个体大气NO₂暴露水平的中位数[四分位数间距（IQR）]为21.47（8.01）μg·m_–3。大气NO₂短期暴露与肥胖个体s CD40L、PAg T升高的关联有统计学意义，关联程度最高出现在累积滞后5 d，大气NO₂累积滞后5 d的滑动平均暴露浓度每增加一个IQR,s CD40L升高27.4%（95%CI:4.2%～56.6%）,PAg T升高37.5%（95%CI:12.2%～68.6%）；大气NO2短期暴露与正常体重个体PLT、PAgT下降的关联有统计学意义，关联程度最高的分别出现在累积滞后5 d和累积滞后7 d，大气NO₂累积滞后5 d的滑动平均暴露浓度每增加一个IQR,PLT下降11.8%（95%CI：–17.8%～–5.3%），累积滞后7 d的滑动平均暴露浓度每增加一个IQR,PAg T下降16.8%（95%CI：–30.6%～–0.4%）。未观察到大气NO₂短期暴露与肥胖个体PLT和正常体重个体s CD40L间的关联。未发现大气NO₂短期暴露与不同体重个体PAI-1、MPV和s P-selectin间的关联。分层分析发现，大气NO₂短期暴露与正常体重组的PAg T以及肥胖组的PLT、sCD40L和sP-selectin间的关联仅在高温时具有统计学意义。[结论]大气NO₂短期暴露可对不同体重年轻个体凝血功能相关指标产生不良影响，与正常体重个体相比，肥胖个体对大气NO₂短期暴露更为敏感。高温可增强大气NO₂短期暴露的不良健康影响。更多还原

【Abstract】 [Background] Nitrogen dioxide（NO₂） is one of the main air pollutants,and though China’s NO₂pollution has been improving year by year,it maintains at a high level,threatening the health of the population.[Objective] To investigate the effect of short-term exposure to atmospheric NO₂ on the coagulation indexes in obese and normal-weight young individuals and potential modification effect of temperature.[Methods] Based on a parallel control panel study design,this study recruited 53 normal-weight and 44 obese young individuals.Three prospective follow-ups were conducted.Air pollution data were obtained from thefixed monito ringstation closestto the participant’s residences,and personal air pollution exposure was simulated based on time-activity log and infiltration factor for the week befo re every follow-up.Temperature was collected from China Meteorological Data Service Center.Venous blood samples were taken to measure platelet（PLT） count,mean platelet volume（MPV）,soluble CD40 ligand（SCD40L）,soluble P-selectin（sP-selectin）,platelet aggregation rate（PAgT）,and plasminogen activator inhibitor type-1（PAI-1） during every follow-up.A linear mixed-effect model was used to assess the association between shortterm atmospheric NO₂ exposure and the coagulation indexes of weight grouped young individuals,and a stratified analysis was used to explore potential modification effect of temperature.[Results] The median [interquartile range（IQR）] of personal atmospheric NO₂ exposure concentrations was 21.47（8.01） μg·m^-3.Shortterm exposure to atmospheric NO₂ was significantly associated the increase of sCD40L and PAgT in the obese individuals,while the most significant association appeared at 5 d lag,and for each IQR increase in the average sliding exposure concentration of atmospheric NO₂with a 5 d lag,sCD40L increased by 27.4%（95%CI:4.2%,56.6%） and PAgT increased by 37.5%（95%CI:12.2%,68.6%）;short-term exposure to atmospheric NO₂ was significantly associated with the decrease of PLT and PAgT in the normal-weight individuals,while the most significant association appeared at 5 d lag or 7 d lag,and for each IQR increase in the average sliding exposure concentration of atmospheric NO₂ with a 5 d lag,P LT decreased by 11.8%（95%CI:-17.8%,-5.3%）,and for each IQR increase in the average sliding exposure concentration of atmospheric NO₂ with a 7 d lag,PAgT decreased by 16.8%（95%CI:-30.6%,-0.4%）.We didn ’t find statistically significant association of short-term exposure to atmospheric NO₂ with PLT in the obese individuals or sCD40L in the normal-weight individuals,nor statistically significant association between short-term exposure to atmospheric NO₂ and PAI-1,MPV,and sP-selectin in different weight grouped individuals.The stratified analysis found that short-term exposure to atmospheric NO₂ was significantly associated with PAgT in the normalweight individuals,or with PLT,sCD40L,and sP-selectin in the obese individuals only at high temperature.[Conclusions] Short-term exposure to atmospheric NO₂ has adverse effects on the coagulation indexes of different weight grouped young individuals,and the obese individuals are more sensitive to it than the normal-weight individuals.High temperature can enhance the adverse health effect of short-term exposure to atmospheric NO₂.更多还原