title: Prospective Associations Between Early Long-Term Household Tobacco Smoke Exposure and Subsequent Indicators of Metabolic Risk at Age 10.
abstract: BACKGROUND
  Although there are established risks associated with gestational tobacco smoke exposure, few studies have addressed the metabolic hazards of domestic exposure in early childhood. This study prospectively examines the long-term relationship between early childhood exposure to household smoke and two adiposity-related measures at age 10.
  
  
  METHODS
  Participants from the Quebec Longitudinal Study of Child Development birth cohort were categorized into one of three groups of early childhood household exposure to tobacco smoke over four time points (from ages 1 to 7 years): never-exposed; transient exposure; and continuous exposure. Follow-up measures of body mass index and waist circumference were independently assessed at age 10.
  
  
  RESULTS
  Compared to being never exposed, transient and continuous household smoke exposure predicted increases of 0.93 cm (95% confidence interval [CI] between 0.05 and 1.82 cm; P = .03) and 1.56 cm (95% CI between 0.07 and 3.05 cm; P = .04) in children's waist circumference, respectively. Children exposed to transient and continuous household smoke, compared to unexposed children, also showed 0.48 and 0.81 point increases in their body mass index, respectively, both Ps = .005. Once adjusted, for confounding variables, only transient household smoke remained associated with 43% greater odds of belonging to the overweight/obese category (95% CI between 1.12 and 1.81 cm; P < .01).
  
  
  CONCLUSIONS
  We found significant long-term prospective associations between home-based secondhand smoke exposure and unhealthy body fat distribution. Waist circumference in youth has become an important risk factor for obesity-related diseases in adulthood. Our findings emphasize the importance public health initiatives and parental sensitization aimed at domestic exposure reductions during the critical early childhood years.
authors.affiliation: Centre de Recherche de l'Hôpital Sainte-Justine, Université de Montréal, Montréal, QC, Canada; École de psychoéducation, Université de Montréal, Montréal, QC, Canada; Linda.S.Pagani@umontreal.ca.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Pagani
authors.affiliation: École de psychoéducation, Université de Montréal, Montréal, QC, Canada;
authors.forename: A K Danny
authors.initials: AK
authors.lastname: Nguyen
authors.affiliation: Department of Exercise Science, PERFORM Centre, Concordia University, Montréal, QC, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Fitzpatrick
mesh_terms: D050154:Adiposity; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005191:Family Characteristics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008659:Metabolic Diseases / Q000175:diagnosis / Q000453:epidemiology; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology; D011446:Prospective Studies; D011792:Quebec / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology*; D013997:Time Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D055105:Waist Circumference
chemical_list: D014028:Tobacco Smoke Pollution