Association Between Chronic Respiratory Diseases and Helicobacter pylori: A Meta-Analysis.

BACKGROUND The prevalence of chronic respiratory diseases (CRDs), including chronic bronchitis and chronic obstructive pulmonary disease (COPD), has increased significantly over the past decades. Several studies suggest that Helicobacter pylori infection may be related to the development of CRDs, but the results were not consistent. We carried out a meta-analysis to evaluate the potential association of H.pylori infection with CRDs. METHODS We conducted a systematic literature search in PubMed, Embase, Ovid, Google Scholar and CNKI from inception to October 31, 2013. The following search terms were used: "chronic respiratory disease," "chronic bronchitis," "chronic obstructive pulmonary disease" or "COPD" in combination with "Helicobacter pylori" or "Campylobacter pylori." According to established inclusion criteria, we selected all eligible published papers and then extracted essential data. To evaluate the association of H.pylori with chronic bronchitis and COPD, an overall analysis and subgroup analyses were conducted. RESULTS A total of 9 case-control studies comprising 782 cases and 815 controls were included in the study. Pooled ORs were 2.30 (95%CI: 1.85-2.85) in the overall analysis, 2.90 (95%CI: 2.04-4.13) in the chronic bronchitis subgroup, and 2.11 (95%CI: 1.35-3.29) in the COPD subgroup. CONCLUSIONS The results of the overall analysis and subgroup analyzed suggest a significant association between H.pylori and CRDs. Further studies are needed to clarify the pathogenetic mechanisms involved.