Association Between Gastric Helicobacter pylori Colonization and Glycated Hemoglobin Levels

Background. Few studies have evaluated the potential influence of Helicobacter pylori on biomarkers for diabetes. Methods. We conducted cross-sectional analyses using data from 7417 participants in the National Health and Nutrition Examination Survey (NHANES) III (aged >= 18 years) and 6072 participants in NHANES 1999-2000 (aged >= 3 years) to assess the association between H. pylori and levels of glycosylated hemoglobin (HbA1c). Results. There was no association between H. pylori and history of self-reported diabetes. Helicobacter pylori seropositivity, especially H. pylori cagA positivity, was positively associated (P < .01, NHANES III; P = .02, NHANES 1999-2000) with HbA1c levels after excluding individuals with history of diabetes and controlling for potential confounders. There was also a synergistic interaction between H. pylori and higher body mass index (BMI), such that increased levels of HbA1c associated with having both H. pylori and higher BMI were greater than the sum of their individual effects (P for interaction < .01). This interaction was observed consistently in both NHANES III and NHANES 1999-2000 and for H. pylori cagA positivity in NHANES III. Conclusions. The findings indicate a role of H. pylori in impaired glucose tolerance in adults that may be potentiated by higher BMI level.