title: Effect of Helicobacter pylori infection on growth trajectories in young Ethiopian children: a longitudinal study.
abstract: BACKGROUND
  Helicobacter pylori infection has been associated with early childhood growth impairment in high- and middle-income countries; however, few studies have examined this relationship within low-income countries or have used a longitudinal design. The possible effects of H. pylori infection on growth trajectories were examined in a cohort of young Ethiopian children.
  
  
  METHODS
  In 2011/12, 856 children (85.1% of the 1006 original singletons in a population-based birth cohort) were followed up at age 6.5 years. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Height and weight were measured twice, and the average of the two measurements was used. Exposure to H. pylori infection was assessed using a rapid H. pylori stool antigen test. The independent associations of positive H. pylori infection status (measured at ages 3 and 6.5 years) with baseline height and weight (age 3 years) and height and weight growth trajectory (from age 3 to 6.5 years) were modelled using hierarchical linear models.
  
  
  RESULTS
  At baseline (age 3 years), the children's mean height was 85.7cm and their mean weight was 11.9kg. They gained height at a mean rate of 8.7cm/year, and weight at a mean rate of 1.76kg/year. H. pylori infection was associated with lower baseline measurements and linear height trajectory (β=-0.74cm and -0.79cm/year, respectively), after controlling for demographics and markers of socio-economic status. However, the positive coefficient was associated with quadratic growth in height among H. pylori-infected children (β=0.28, 95% confidence interval 0.07 to 0.49, p<0.01), and indicated an increase in height trajectory as the child increased in age. A non-significant difference in baseline and trajectory of weight was observed between H. pylori-infected and non-infected children.
  
  
  CONCLUSIONS
  These findings add to the growing body of evidence supporting that H. pylori infection is inversely associated with childhood growth trajectory, after controlling for a range of factors associated with reduced growth and H. pylori status. Further follow-up will be important to confirm possible catch-up in height trajectory among H. pylori-infected children as they grow older.
authors.affiliation: Colgate University, Department of Biology, 214 Olin Hall, 13 Oak Dr, Hamilton, NY, 13346, USA; School of Public Health, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia. Electronic address: btaye@colgate.edu.
authors.forename: Bineyam
authors.initials: B
authors.lastname: Taye
authors.affiliation: School of Public Health, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Fikre
authors.initials: F
authors.lastname: Enquselassie
authors.affiliation: School of Allied Health Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Aster
authors.initials: A
authors.lastname: Tsegaye
authors.affiliation: Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Alemayehu
authors.initials: A
authors.lastname: Amberbir
authors.affiliation: Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
authors.forename: Girmay
authors.initials: G
authors.lastname: Medhin
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, Nottingham, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Fogarty
authors.affiliation: Nottingham Digestive Diseases Biomedical Research Unit, School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Robinson
authors.affiliation: Wellcome Trust Centre for Global Health Research, Brighton and Sussex Medical School, Brighton, UK.
authors.forename: Gail
authors.initials: G
authors.lastname: Davey
mesh_terms: D001827:Body Height; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D015331:Cohort Studies; D005002:Ethiopia; D005243:Feces / Q000382:microbiology; D005260:Female; D016481:Helicobacter Infections / Q000191:economics / Q000382:microbiology / Q000503:physiopathology*; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011203:Poverty; D011795:Surveys and Questionnaires
keywords: Birth cohort; Ethiopia; Growth trajectory; Helicobacter pylori