title: The relationship between Helicobacter pylori seropositivity and COPD.
abstract: BACKGROUND
  Chronic systemic infections such as those with Helicobacter pylori (H. pylori) may contribute to the evolution and progression of chronic obstructive pulmonary disease (COPD). Using data from the Lung Health Study (LHS), we determined the relationship of H. pylori infection with the severity and progression of COPD.
  
  
  METHODS
  Using an immunoassay, we measured H. pylori immunoglobulin G (IgG) antibody titres in serum samples of 4765 patients with mild-to-moderate COPD. We then determined their relationship with the individual's FEV1 and the rate of decline in FEV1 and mortality over 11 years using multiple regression analysis.
  
  
  RESULTS
  Approximately 18% of the patients were seropositive to H. pylori and these individuals demonstrated lower FEV1 (L) values at every study visit compared with individuals who were seronegative for H. pylori (p value=0.00012). However, patients with seropositivity to H. pylori were on average 0.012 m shorter than those with seronegativity (p value=0.0015). The significant relationship between FEV1 and H. pylori seropositivity disappeared when FEV1 per cent predicted (FEV1pp) was used (p value=0.45). H. pylori seropositive individuals had greater circulating C reactive protein (CRP) levels compared with H. pylori seronegative individuals (p value=0.012), and had increased risk of cardiovascular mortality (relative risk 1.61, p=0.05).
  
  
  CONCLUSIONS
  H. pylori infection was associated with reduced lung function that is most likely due to the effect of the bacterium on lung growth earlier in life. It is also associated with systemic inflammation and increased risk of cardiovascular mortality in patients with COPD.
  
  
  BACKGROUND
  NCT00000568 and NCT00000569.
authors.affiliation: Department of Medicine (Division of Respiratory Medicine), Centre for Heart Lung Innovation, Providence Heart/Lung Institute at St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Sze
authors.affiliation: Department of Medicine (Division of Respiratory Medicine), Centre for Heart Lung Innovation, Providence Heart/Lung Institute at St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Yu-Wei Roy
authors.initials: YW
authors.lastname: Chen
authors.affiliation: Department of Medicine (Division of Respiratory Medicine), Centre for Heart Lung Innovation, Providence Heart/Lung Institute at St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Sheena
authors.initials: S
authors.lastname: Tam
authors.affiliation: Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
authors.forename: Donald
authors.initials: D
authors.lastname: Tashkin
authors.affiliation: Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Wise
authors.affiliation: Division of Biostatistics, University of Minnesota School of Public Health, Minneapolis, Minnesota, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Connett
authors.affiliation: Department of Medicine (Division of Respiratory Medicine), Centre for Heart Lung Innovation, Providence Heart/Lung Institute at St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Sf Paul
authors.initials: SP
authors.lastname: Man
authors.affiliation: Department of Medicine (Division of Respiratory Medicine), Centre for Heart Lung Innovation, Providence Heart/Lung Institute at St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Don D
authors.initials: DD
authors.lastname: Sin
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D016481:Helicobacter Infections / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000382:microbiology* / Q000401:mortality / Q000503:physiopathology; D012044:Regression Analysis; D012307:Risk Factors
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G
keywords: COPD epidemiology; Respiratory Infection