title: Mediating role of maternal serum interleukin-1beta and tumor necrosis factor-alpha in the association between environmental tobacco smoke exposure in pregnancy and low birth weight at term.
abstract: OBJECTIVE
  To explore the mediation effects of maternal serum interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) on the association between environmental tobacco smoke (ETS) exposure during pregnancy and low birth weight (LBW) at term.
  
  
  METHODS
  ETS exposure, birth weight, blood sample and covariates were collected from 195 pregnant women delivered term LBW infants and 195 controls delivered normal birth weight infants in two Maternity and Child Hospitals in Guangdong, China. Maternal serum IL-1β and TNF-α were measured by flow cytometry. Logistic regression models and path analyses explored the mediation effects of maternal IL-1β and TNF-α on the association between ETS exposure and LBW.
  
  
  RESULTS
  LBW was significantly associated with maternal ETS exposure (OR = 2.14 (95% CI =1.06-4.32)). TNF-α and IL-1β were significantly associated with both LBW (OR = 1.87 (1.41-2.47) and OR = 1.53 (1.14-2.05)) and ETS (β = 0.32 (0.04-0.60) and β = 0.27 (0.05-0.49)). Traditional mediation analyses indicated the separate mediation effect of TNF-α and IL-1β was 32.2% and 24.6%, respectively. Path analysis revealed the combined mediation effects of TNF-α and IL-1β as 29.4% in the pathway from ETS exposure to LBW.
  
  
  CONCLUSIONS
  Maternal serum IL-1β and TNF-α may play a mediating role in the association between maternal ETS exposure during pregnancy and term LBW.
authors.affiliation: a Department of Biostatistics and Epidemiology, School of Public Health , Sun Yat-sen University , Guangzhou , PR China.
authors.forename: Zhongzheng
authors.initials: Z
authors.lastname: Niu
authors.affiliation: b Department of Cancer Prevention Research, State Key Laboratory of Oncology in South China , Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center , Guangzhou , PR China.
authors.forename: Chuanbo
authors.initials: C
authors.lastname: Xie
authors.affiliation: c Department of Pediatrics, Division of Behavioral Medicine, School of Medicine and Biomedical Sciences , State University of New York at Buffalo , Buffalo , NY , USA.
authors.forename: Xiaozhong
authors.initials: X
authors.lastname: Wen
authors.affiliation: a Department of Biostatistics and Epidemiology, School of Public Health , Sun Yat-sen University , Guangzhou , PR China.
authors.forename: Fuying
authors.initials: F
authors.lastname: Tian
authors.affiliation: a Department of Biostatistics and Epidemiology, School of Public Health , Sun Yat-sen University , Guangzhou , PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Ding
authors.affiliation: a Department of Biostatistics and Epidemiology, School of Public Health , Sun Yat-sen University , Guangzhou , PR China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: He
authors.affiliation: a Department of Biostatistics and Epidemiology, School of Public Health , Sun Yat-sen University , Guangzhou , PR China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Fan
authors.affiliation: d Shenzhen Women and Children's Hospital , Shenzhen , PR China.
authors.forename: Shixin
authors.initials: S
authors.lastname: Yuan
authors.affiliation: e Foshan Women and Children's Hospital , Foshan , PR China.
authors.forename: Deqin
authors.initials: D
authors.lastname: Jia
authors.affiliation: a Department of Biostatistics and Epidemiology, School of Public Health , Sun Yat-sen University , Guangzhou , PR China.
authors.forename: Wei-Qing
authors.identifier: http://orcid.org/0000-0002-3877-0794
authors.initials: WQ
authors.lastname: Chen
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D053583:Interleukin-1beta / Q000097:blood*; D016015:Logistic Models; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D053583:Interleukin-1beta; D014028:Tobacco Smoke Pollution; D014409:Tumor Necrosis Factor-alpha
keywords: Environmental tobacco smoke; inflammation; low birth weight; mediation