Association of CagA-positive Helicobacter pylori infection with severity of obstructive sleep apnea syndrome

Aim: To investigate the association between Helicobacter pylori cytotoxin-associated gene-A (CagA) status and the severity of OSA syndrome in infected patients. Methods: Ninty-six patients with obstructive sleep apnea syndrome (OSAS) and 30 age-and sex-matched control subjects with no history of OSA or gastrointestinal complaints were included in the study. Patients' apnea-hypopnea index (AHI) was determined by polysomnography (PSG), and serum H. Pylori IgG and cytotoxin-associated gene-A IgG was assayed by enzyme-linked immunosorbent assay (ELISA). Based on their AHI score, subjects were assigned to one of three groups: a control group (AHI<5), a mild-moderate OSAS group (AHI >= 5 and < 30), and a severe OSAS group (AHI >= 30). Results: The prevalence of H. pylori IgG seropositivity was significantly higher in the severe OSAS group compared to the mild-moderate OSAS group [ 29 (90.6%) patients versus 41 (64%) patients, (p=0.007)]. In addition, CagA seropositivity was present in 10 control patients (58.8%), 23 mild-moderate OSAS patients (56%), and 25 severe OSAS patients (86.2%). There was a significantly higher prevalence of CagA seropositivity in the severe OSAS group compared to mild-moderate OSAS group (p=0.027). There was no significant difference in CagA seropositivity between the mild-moderate OSAS group and the control group (p=0.059). Conclusion: Our findings suggest that H. pylori strains expressing CagA may be considered a risk factor in the severity of OSAS.