title: Sibship size, Helicobacter pylori infection and chronic atrophic gastritis: a population-based study among 9444 older adults from Germany.
abstract: BACKGROUND
  Early-life social environment has been suggested to play an important role during the development of Helicobacter pylori-related gastric diseases. We aimed to assess the association of sibship size with H. pylori infection and chronic atrophic gastritis (CAG) in a population-based study from Germany.
  
  
  METHODS
  In the baseline examination of ESTHER, a study conducted in Saarland, serological measurements of pepsinogen I and II and H. pylori antibodies were taken in 9444 participants aged 50-74 years. Information on potential risk factors and medical history were obtained by self-administered standardized questionnaire.
  
  
  RESULTS
  A strong dose-response relationship between sibship size and H. pylori seroprevalence was observed (P < 0.01). Adjusted odds ratios (ORs) 95% confidence interval (CI) for H. pylori seropositivity for subjects with 4, 5, 6 and 7 or more siblings compared with subjects without siblings were 1.45 (1.20-1.77), 1.83 (1.50-2.22) and 1.84 (1.47-2.31), respectively. A large sibship size was also associated with an increased risk of CAG with an adjusted OR of 1.42 (1.01-2.01) for 7 or more compared with less than or equal to 2 siblings. This association was attenuated but not entirely eliminated after additional adjustment for H. pylori infection. Notably, a significant association between large sibship size and CAG was also found among H. pylori-negative subjects.
  
  
  CONCLUSIONS
  Our results suggest that large sibship size is associated with increased H. pylori prevalence and CAG risk. The association with CAG risk may be mediated at least in part by H. pylori infection. However, mechanisms other than H. pylori infection may contribute to the 'sibling effect' as well.
authors: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Heidelberg, Germany.
authors: Lei
authors: L
authors: Gao
authors: Melanie N
authors: MN
authors: Weck
authors: Elke
authors: E
authors: Raum
authors: Christa
authors: C
authors: Stegmaier
authors: Dietrich
authors: D
authors: Rothenbacher
authors: Hermann
authors: H
authors: Brenner
mesh_terms: D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D005260:Female; D005757:Gastritis, Atrophic / Q000453:epidemiology* / Q000209:etiology; D005858:Germany / Q000453:epidemiology; D016481:Helicobacter Infections / Q000150:complications / Q000453:epidemiology*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D020116:Pepsinogen A / Q000097:blood; D020115:Pepsinogen C / Q000097:blood; D012307:Risk Factors; D035781:Siblings; D012959:Socioeconomic Factors
chemical_list: D000907:Antibodies, Bacterial; D020115:Pepsinogen C; D020116:Pepsinogen A