title: Effects of in utero and Postnatal Exposure to Secondhand Smoke on Lung Function by Gender and Asthma Status: The Seven Northeastern Cities (SNEC) Study.
abstract: BACKGROUND
  Little information exists on whether gender or asthma status modifies the effects of secondhand smoke (SHS) exposure on lung function.
  
  
  OBJECTIVE
  To evaluate whether gender or asthma status modifies the association of SHS exposure with lung function.
  
  
  METHODS
  A total of 6,740 children (average 11.6 years) were recruited from 24 districts of 7 cities in northeast China in 2012. SHS exposure included exposure to environmental and maternal smoking both in utero and during early childhood (postnatal). Lung function was measured using electronic spirometers. Two-step regressions were used to analyze the association between SHS and lung function.
  
  
  RESULTS
  In utero and postnatal exposure to SHS was independently associated with decreased lung function in both genders; however, this association was greater among males. For example, when exposed to maternal smoking during pregnancy, the adjusted odds ratio (aOR) for decreased forced vital capacity (FVC) was 6.46 (95% confidence interval [CI]: 2.58-16.17) among males, while only 2.16 (95% CI: 0.96-4.88) among females. More positive associations between SHS exposure and decreased lung function were detected among nonasthmatic compared with asthmatic children. Nonasthmatics had significantly larger deficits from in utero exposure to maternal smoking, which concerned decreased lung FVC function (aOR = 2.58, 95% CI: 1.28-5.21) and decreased lung forced expiratory volume in 1 s (FEV1) function (aOR = 2.32, 95% CI: 1.01-5.33). A similar pattern was also observed for the associations between SHS exposure and continuous pulmonary function test measurements.
  
  
  CONCLUSIONS
  SHS exposure was associated with decreased lung function. Males and nonasthmatics seem to be more susceptible than their respective counterparts.
authors.affiliation: Guangzhou Key Laboratory of Environmental Pollution and Health Risk Assessment, Department of Preventive Medicine, School of Public Health, Sun Yat-sen University, Guangzhou, China.
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Hu
authors.forename: Mo
authors.initials: M
authors.lastname: Yang
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.forename: Kuntal
authors.initials: K
authors.lastname: Shah
authors.forename: Yismaw
authors.initials: Y
authors.lastname: Hailegiorgis
authors.forename: Richai
authors.initials: R
authors.lastname: Burgens
authors.forename: Michael
authors.initials: M
authors.lastname: Vaughn
authors.forename: Jin
authors.initials: J
authors.lastname: Huang
authors.forename: Pamela
authors.initials: P
authors.lastname: Xaverius
authors.forename: Gunther
authors.initials: G
authors.lastname: Paul
authors.forename: Lidia
authors.initials: L
authors.lastname: Morawska
authors.forename: Tao
authors.initials: T
authors.lastname: Lu
authors.forename: Shao
authors.initials: S
authors.lastname: Lin
authors.forename: Shou-Qiang
authors.initials: SQ
authors.lastname: Zhong
authors.forename: Min-Li
authors.initials: ML
authors.lastname: Kong
authors.forename: Yan-Qi
authors.initials: YQ
authors.lastname: Xie
authors.forename: Yuan-Tao
authors.initials: YT
authors.lastname: Hao
authors.forename: Xiao-Wen
authors.initials: XW
authors.lastname: Zeng
authors.forename: Zhengmin
authors.initials: Z
authors.lastname: Qian
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Dong
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology / Q000503:physiopathology*; D002648:Child; D002681:China / Q000453:epidemiology; D002947:Cities; D004781:Environmental Exposure; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology / Q000503:physiopathology*; D012044:Regression Analysis; D012737:Sex Factors; D013147:Spirometry; D014028:Tobacco Smoke Pollution; D014797:Vital Capacity
chemical_list: D014028:Tobacco Smoke Pollution