Dyspeptic symptoms associated with Helicobacter pylori infection are influenced by strain and host specific factors

Background: Dyspepsia can be associated with H. pylori infection. Aim: To assess dyspeptic symptoms and potentially influencing factors before and up to 6 months following successful H. pylori eradication therapy. Methods: Prospective cohort study involving H. pylori positive subjects from ambulatory or hospitalized care. Main outcome measures were symptoms during baseline and follow-up, the proportion of symptom-free patients, and symptom scores. Results: After successful eradication, the summary score of all dyspeptic symptoms decreased and during follow-up, the proportion of symptom-free patients was higher in the group with peptic ulcers (69.4% vs. 40.9%, P < 0.0001) than with functional dyspepsia (FD). Regardless of diagnosis, virulent strains of H. pylori were associated with a higher prevalence of epigastric pain before treatment: absolute risk-difference (ARD) with Oip-A: 18.2%, Odds Ratio (OR) 2.35 [1.3-4.2, 95%-CI], P = 0.01; with Cag-A: 24.6%, OR 2.81 [1.6-5], P = 0.01. Low-dose aspirin in part was a major risk factor in FD for previous weight loss bdfore study entry. Post-treatment, non-ulcer patients were more likely to suffer from distention/bloating. Likewise, alcohol induced persistence of nausea and vomiting in this population. Conclusions: Dyspeptic symptoms in H. pylori infected patients are more common with virulent strains. Symptoms are more likely to persist despite successful eradication if patients initially harboured virulent strains or concomitant aspirin or alcohol intake are present. In one-third of peptic ulcer patients, symptoms will not be cured 3 months after therapy.