Xie Chuanbo, Wen Xiaozhong, Niu Zhongzheng, Ding Peng, Liu Tao, He Yanhui, Lin Jianmiao, Yuan Shixin, Guo Xiaoling, Jia Deqin, Chen Weiqing
Department of Biostatistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China;
Division of Behavioral Medicine, Department of Pediatrics, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY;
Nicotine Tob Res. 2015 Dec;17(12):1421-7. doi: 10.1093/ntr/ntv072. Epub 2015 Apr 6.
Risk of small-for-gestational-age (SGA) birth varied considerably in women exposed to secondhand smoke (SHS) during pregnancy. We examined whether this variation was explained by mothers' one Phase I (CYP2A6*4, activation of tobacco toxics) and two Phase II (GSTM1 and GSTT1, detoxification) metabolic genotypes.
We enrolled 468 Chinese pregnant women (115 delivering SGA and 353 delivering non-SGA newborns) shortly before delivery. SHS exposure during pregnancy was defined as self-reported daily exposure time being more than 0 minute. We fitted multivariable logistic regression models to examine whether CYP2A6*4, GSTM1, and GSTT1 gene polymorphsims and their combinations modified the association between SHS exposure and SGA.
In the total sample, more mothers of SGA newborns were exposed to SHS during pregnancy than mothers of non-SGA newborns (38.3% vs. 31.4%). CYP2A64, GSTM1, and GSTT1 genes alone could not modify the association between SHS exposure and SGA. The combination of CYP2A64 and GSTT1 high-risk genotypes (CYP2A6*1/*1 and GSTT1-absent [high-risk] vs. other combinations as a whole [low-risk]) significantly (P value, .045) modified the association between SHS exposure and SGA. Among mothers with high-risk genotypes, SHS during pregnancy was significantly associated with SGA (confounder-adjusted odds ratio, 2.31 [95% confidence interval, 1.20-4.42]). Among mothers with low-risk genotypes, however, SHS exposure during pregnancy was not associated with SGA (1.14 [0.64-2.04]).
Chinese pregnant women with the combination of CYP2A6*1/*1 and GSTT1-absent genotypes are at particularly high-risk of SHS-related SGA.
孕期接触二手烟（SHS）的女性中，小于胎龄儿（SGA）出生风险差异很大。我们研究了这种差异是否由母亲的一种I相（CYP2A6*4，烟草毒物激活）和两种II相（GSTM1和GSTT1，解毒）代谢基因型所解释。
我们在分娩前不久招募了468名中国孕妇（115名分娩SGA新生儿，353名分娩非SGA新生儿）。孕期SHS暴露定义为自我报告的每日暴露时间超过0分钟。我们拟合多变量逻辑回归模型，以研究CYP2A6*4、GSTM1和GSTT1基因多态性及其组合是否改变了SHS暴露与SGA之间的关联。
在总样本中，与非SGA新生儿的母亲相比，SGA新生儿的母亲在孕期接触SHS的更多（38.3%对31.4%）。单独的CYP2A64、GSTM1和GSTT1基因不能改变SHS暴露与SGA之间的关联。CYP2A64和GSTT1高风险基因型的组合（CYP2A6*1/*1和GSTT1缺失[高风险]与其他组合整体[低风险]）显著（P值，0.045）改变了SHS暴露与SGA之间的关联。在高风险基因型的母亲中，孕期SHS与SGA显著相关（混杂因素调整后的优势比，2.31[95%置信区间，1.20 - 4.42]）。然而，在低风险基因型的母亲中，孕期SHS暴露与SGA无关（1.14[0.64 - 2.04]）。
具有CYP2A6*1/*1和GSTT1缺失基因型组合的中国孕妇患与SHS相关的SGA的风险特别高。
