title: Developmental trajectories of Body Mass Index from infancy to 18 years of age: prenatal determinants and health consequences.
abstract: BACKGROUND
  Knowledge on the long-term development of adiposity throughout childhood/adolescence and its prenatal determinants and health sequelae is lacking. We sought to (1) identify trajectories of Body Mass Index (BMI) from 1 to 18 years of age, (2) examine associations of maternal gestational smoking and early pregnancy overweight with offspring BMI trajectories and (3) determine whether BMI trajectories predict health outcomes: asthma, lung function parameters (forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio), and blood pressure, at 18 years.
  
  
  METHODS
  The Isle of Wight birth cohort, a population-based sample of 1456 infants born between January 1989 and February 1990, was prospectively assessed at ages 1, 2, 4, 10 and 18 years. Group-based trajectory modelling was applied to test for the presence of latent BMI trajectories. Associations were assessed using log-binomial and linear regression models.
  
  
  RESULTS
  Four trajectories of BMI were identified: 'normal', 'early persistent obesity', 'delayed overweight', and 'early transient overweight'. Risk factors for being in the early persistent obesity trajectory included maternal smoking during pregnancy (RR 2.16, 95% CI 1.02 to 4.68) and early pregnancy overweight (3.16, 1.52 to 6.58). When comparing the early persistent obesity to the normal trajectory, a 2.15-fold (1.33 to 3.49) increased risk of asthma, 3.2% (0.4% to 6.0%) deficit in FEV1/FVC ratio, and elevated systolic 11.3 mm Hg (7.1 to 15.4) and diastolic 12.0 mm Hg (8.9 to 15.1) blood pressure were observed at age 18 years.
  
  
  CONCLUSIONS
  Maternal prenatal exposures show prolonged effects on offspring's propensity towards overweight-obesity. Distinct morbid BMI trajectories are evident during the first 18 years of life that are associated with higher risk of asthma, reduced FEV1/FVC ratio, and elevated blood pressure.
authors.affiliation: Department of Epidemiology and Biostatistics, Norman J. Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA Department of Community Medicine and Behavioral Sciences, Faculty of Medicine, Kuwait University, Kuwait.
authors.forename: Ali H
authors.initials: AH
authors.lastname: Ziyab
authors.affiliation: Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Memphis, Memphis, Tennessee, USA.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Karmaus
authors.affiliation: David Hide Asthma and Allergy Research Centre, Isle of Wight, UK.
authors.forename: Ramesh J
authors.initials: RJ
authors.lastname: Kurukulaaratchy
authors.affiliation: Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Memphis, Memphis, Tennessee, USA.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: David Hide Asthma and Allergy Research Centre, Isle of Wight, UK Academic Unit of Clinical and Experimental Medicine, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Syed Hasan
authors.initials: SH
authors.lastname: Arshad
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology / Q000209:etiology*; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000209:etiology*; D007223:Infant; D008297:Male; D015999:Multivariate Analysis; D063766:Pediatric Obesity / Q000453:epidemiology / Q000209:etiology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000502:physiology; D011297:Prenatal Exposure Delayed Effects; D012123:Pulmonary Ventilation / Q000502:physiology*; D012907:Smoking / Q000009:adverse effects*; D006113:United Kingdom / Q000453:epidemiology; D015430:Weight Gain / Q000502:physiology
keywords: Asthma; Epidemiology; Maternal Health; Obesity; Paediatric