Helicobacter pylori infection and UBT-13C values are associated with changes in body mass index in children and adults.

Background: The urea breath test (UBT-13C) is a non-invasive technique that allows the diagnosis and confirmation of eradication of Helicobacter pylori infection.

Aim: To evaluate H. pylori positivity and values of UBT-13C among infected Chilean children and adults, and to analyze its variation in relation to sex, nutritional status, and age of the patients.

Material and methods: Retrospective study of 1141 patients aged 6 to 94 years, with an indication for a UBT-13C either for diagnosis or for confirmation of eradication of H. pylori infection. 13C enrichment was measured using an infrared spectrometer calculating the delta 13C values before and after the ingestion of 13C marked urea. The clinical data of the patients were obtained at the time of the examination.

Results: We included 241 children and 900 adults. Infected children obtained lower UBT-13C delta values than infected adults (16.1 ± 8.7 and 37 ± 52.9, respectively). The rates of infection were higher in males who were recruited for diagnosis. Significant differences were obtained between positivity for H. pylori in overweight and obese children but not adults. UBT-13C titers were significantly associated with the body mass index (BMI) only in adults.

Conclusions: H. pylori infection rates are similar between sexes and are higher in children probably because of selection bias. In children, H. pylori positivity is associated with higher BMI and excess malnutrition although with similar UBT-13C values. In adults, H. pylori infection is not related with BMI, but a higher BMI impacts UBT-13C titers.