中介或混杂因素:是否应调整肥胖以估计三卤甲烷对甲状腺功能的影响  

Mediators or confounders:should obesity be adjusted to estimate the effects of trihalomethanes on thyroid function

作　　者：范佳旭 成芳 乔俊鹏 费海程 陈学禹 赵云 贾红英[3,4] FAN Jiaxu;CHENG Fang;QIAO Junpeng;FEI Haicheng;CHEN Xueyu;ZHAO Yun;JIA Hongying(Department of Biostatistics,School of Public Health,Shandong University,Jinan 250012,Shandong,China;Licheng District Center for Disease Control and Prevention,Jinan 250100,Shandong,China;The Second Hospital,Shandong University,Jinan 250033,Shandong,China;Shenzhen Institute of Shandong University,Shenzhen 518057,Guangdong,China)

机构地区：[1]山东大学公共卫生学院生物统计学系,山东济南250012 [2]济南市历城区疾病预防控制中心,山东济南250100 [3]山东大学第二医院,山东济南250033 [4]山东大学深圳研究院,广东深圳518057

出　　处：《山东大学学报（医学版）》2024年第1期102-110,共9页Journal of Shandong University:Health Sciences

基　　金：中央引导地方科技发展资金自由探索类基础研究项目(2021Svup070);山东大学第二医院科研发展基金(11681808)。

摘　　要：目的探究肥胖以混杂因素还是中介因素在三卤甲烷对甲状腺功能的影响过程中发挥作用。方法使用NHANES数据库中的横断面数据,分别使用加权秩和检验和χ2检验来比较连续变量和分类变量。对偏态分布的变量进行自然ln转换,根据ln转化浓度的四分位数分布对THM进行分类,引入有向无环图(directed acyclic graphs,DAGs)和Logisitic回归探讨肥胖的代理变量BMI在THM暴露与甲状腺功能的因果路径上发挥的潜在作用。结果额外调整BMI(作为分类变量)前后对THM暴露与甲状腺功能的关联无显著影响;但依据肥胖与否进行分层分析时,在肥胖患者中观察到THM是TSH水平升高的危险因素。结论考虑到对撞机偏倚,需要谨慎解释在肥胖分层分析中观察到的潜在异质性,以及谨慎考虑肥胖在THM研究作为混杂和/或中介进行额外分析的必要性。Objective To explore whether obesity plays a confounding or mediating role in the effects of trihalomethanes on thyroid function.Methods The cross-sectional data were obtained from the NHANES database.The continuous and categorical variables were compared with weighted rank sum test andχ2 tests,respectively.Variables with skewed distribution were subjected to natural ln transformation;THM was classified according to the quartile distribution of ln transformed concentration;directed acyclic graphs(DAGs)and Logistic regression were introduced to explore the potential role of body mass index(BMI)in the causal pathway of THM exposure and thyroid function.Results There was no significant effect on the association between THM exposure and thyroid function before and after additional adjustment for BMI as a categorical variable;however,when stratified analyses were performed based on obesity,THM was a risk factor for elevated TSH levels in obese patients.Conclusion Considering collider bias,the potential heterogeneity observed in stratified analyses of obesity needs to be interpreted with caution,as well as the need for additional analyses of obesity as a confounder and/or mediator in THM studies.

关 键 词：中介效应 混杂因素 有向无环图 三卤甲烷 肥胖 

分 类 号：Q451[生物学—生理学]