title: Risk of esophagitis among individuals born preterm or small for gestational age.
abstract: OBJECTIVE
  The association between gastroesophageal reflux and esophageal adenocarcinoma is likely to be mediated by inflammation. Reflux is common in infancy; the esophageal mucosa of infants born preterm or small for gestational age (SGA) could be particularly vulnerable. We investigated the association between preterm or SGA birth and risk of esophagitis early in life.
  
  
  METHODS
  We analyzed data from the Swedish birth register and the Swedish patient register to identify birth characteristics of individuals with endoscopically verified esophagitis from 1973 to 2007 and to determine their outcomes (7358 cases). Five controls were selected randomly and matched with each case (N = 38,479). Multivariable conditional logistic regression models were used to provide odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for potential confounding.
  
  
  RESULTS
  The risk of esophagitis was increased among individuals born preterm (≤32 gestational weeks) (OR, 2.74; 95% CI, 2.15-3.49) or SGA (OR, 1.49; 95% CI, 1.32-1.68). When data were stratified by age at diagnosis and by sex, different risk patterns appeared. Among individuals diagnosed with esophagitis 9 years of age and younger, the OR for prematurity was 6.82 (95% CI, 4.65-10.03) and the OR for SGA at birth was 1.98 (95% CI, 1.55-2.52). Furthermore, the association with preterm birth was stronger among males (OR, 9.88; 95%, CI 5.93-16.45) than females (OR, 3.41; 95% CI, 1.81-6.41), whereas the association with SGA was stronger among females (OR, 2.50; 95% CI, 1.76-3.55) than males (OR, 1.64; 95% CI, 1.16-2.30). The risk of being diagnosed with esophagitis at age 20 or younger was not associated with preterm birth (OR, 1.02; 95% CI, 0.64-1.63), but was associated with being SGA at birth (OR, 1.31; 95% CI, 1.11-1.54).
  
  
  CONCLUSIONS
  Preterm birth is associated with esophagitis only during childhood, whereas SGA birth is associated with esophagitis during adolescence as well. The associations appear to differ between sexes.
authors.affiliation: Department of Medicine, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden. lina.forssell@ki.se
authors.forename: Lina
authors.initials: L
authors.lastname: Forssell
authors.forename: Sven
authors.initials: S
authors.lastname: Cnattingius
authors.forename: Matteo
authors.initials: M
authors.lastname: Bottai
authors.forename: Jesper
authors.initials: J
authors.lastname: Lagergren
authors.forename: Anders
authors.initials: A
authors.lastname: Ekbom
authors.forename: Olof
authors.initials: O
authors.lastname: Akre
mesh_terms: D000328:Adult; D004941:Esophagitis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D047928:Premature Birth; D018570:Risk Assessment; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult