title: BMI, waist circumference at 8 and 12 years of age and FVC and FEV1 at 12 years of age; the PIAMA birth cohort study.
abstract: BACKGROUND
  In adults, overweight is associated with reduced lung function, in children evidence on this association is conflicting. We examined the association of body mass index (BMI) and waist circumference (WC) at age 12, and of persistently (at ages 8 and 12 years) high BMI and large WC, with forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) at age 12.
  
  
  METHODS
  Height, weight, WC and FVC and FEV1 were measured during a medical examination in 1288 12-year-olds participating in the PIAMA birth cohort study. 1090 children also had BMI and WC measured at age 8. The associations between BMI and WC and FVC, FEV1, and FEV1/FVC ratio were studied using local and linear regression analyses, separately for girls and boys. The regression models were adjusted for age, height, and pubertal development and maternal educational level.
  
  
  RESULTS
  High BMI and large WC (sd-score >90th percentile) were associated with higher FVC; in girls these associations were statistically significant (4.6% (95% CI: 1.5, 7.9) and 3.6% (95% CI: 0.6, 6.8) respectively in adjusted models). Similar associations were observed for persistently high BMI or large WC: girls with a high BMI or large WC at both 8 and 12 years had statistically significantly higher FVC at age 12 years (BMI: 4.9% (95% CI 0.9, 9.1), WC: 5.0% (95% CI 0.7, 9.6)) than girls with normal BMI or WC at both ages. No statistically significant associations were observed between (persistently) high BMI or large WC and FEV1. The FEV1/FVC ratio was statistically significantly lower in children with a high BMI or large WC than in children with a normal BMI or WC. Girls and boys with a persistently high BMI or large WC status had statistically significantly lower FEV1/FVC ratios.
  
  
  CONCLUSIONS
  At 12 years of age, a persistently high BMI or large WC is not yet associated with lower FVC and FEV1, suggesting that this association, that is commonly observed in adults, develops at a later age.
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands. m.bekkers@hotmail.com.|Centre for Nutrition, Prevention and Health Services, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands. m.bekkers@hotmail.com.
authors.forename: Marga B
authors.initials: MB
authors.lastname: Bekkers
authors.affiliation: Centre for Nutrition, Prevention and Health Services, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands. alet.wijga@rivm.nl.
authors.forename: Alet H
authors.initials: AH
authors.lastname: Wijga
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands. u.gehring@uu.nl.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Gehring
authors.affiliation: Department of Pulmonology and Pediatric Allergology, GRIAC Research Institute, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands. g.h.koppelman@umcg.nl.
authors.forename: Gerard H
authors.initials: GH
authors.lastname: Koppelman
authors.affiliation: Department of Pediatrics, Erasmus University Medical Center, Sophia Children's Hospital, Rotterdam, The Netherlands. j.c.dejongste@erasmusmc.nl.
authors.forename: Johan C
authors.initials: JC
authors.lastname: de Jongste
authors.affiliation: Julius Centre for Health Sciences and Primary Care, University Medical Center, Utrecht, The Netherlands. H.A.Smit@umcutrecht.nl.
authors.forename: Henriette A
authors.initials: HA
authors.lastname: Smit
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands. b.brunekreef@uu.nl.|Julius Centre for Health Sciences and Primary Care, University Medical Center, Utrecht, The Netherlands. b.brunekreef@uu.nl.
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
mesh_terms: D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D050177:Overweight / Q000453:epidemiology / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012307:Risk Factors; D014797:Vital Capacity / Q000502:physiology*; D055105:Waist Circumference / Q000502:physiology*