Helicobacter pylori infection and abdominal symptoms among Swedish school children.
BACKGROUND
The role of Helicobacter pylori infection in the etiology of abdominal symptoms remains unclear. Our aim was to investigate the association between type-specific H. pylori infection and gastrointestinal symptoms among school children in Stockholm, Sweden.


METHODS
In a community-based cross-sectional study, 695 children aged 10-12 years participated with a blood sample and a questionnaire on sociodemographic characteristics and gastrointestinal symptoms, including minor abdominal pain not necessitating medical consultation, during the preceding six months. Infection was investigated by an enzyme-linked immuno-sorbent assay and confirmed by immunoblot and urea breath test.


RESULTS
Abdominal pain was reported by 440 (63%) children and recurrent abdominal pain (RAP) by 88 (13%). Of 112 (16%) infected children, 73% had antibodies to CagA and 59% to VacA. There was no positive association between H. pylori status and the occurrence of abdominal pain; in fact, the association with any abdominal pain report was inverse (odds ratio [OR] 0,5; 95% Confidence Interval [CI] 0.3-0.8), while RAP was unrelated to the infection (OR 1.0; 95% CI 0.5-2.1) when adjusted for gender, age and family background variables. The prevalence of RAP tended to be lower among children harboring CagA+/VacA+ infections than among the uninfected (adjusted OR 0.3; 95%CI 0.1-1.1). Furthermore, CagA+/VacA+ infected children reported less acid regurgitation (adjusted OR 0.2; 95% CI 0.1-0.5).


CONCLUSIONS
Taking background factors into account, the presence of H. pylori is not accompanied by an increased occurrence of abdominal symptoms in Swedish 10-12-year-olds. However, unexpected differential associations with strain specific infections may indicate a so far overlooked complex relationship that needs to be further confirmed.
Tindberg
Ylva
Y
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. nictin@ki.se
Nyrén
Olof
O
Blennow
Margareta
M
Granström
Marta
M
D015746:Abdominal Pain / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D000293:Adolescent; D001944:Breath Tests; D002648:Child; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology*; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D015151:Immunoblotting; D008297:Male; D016017:Odds Ratio; D012008:Recurrence; D013548:Sweden / Q000453:epidemiology