Significance of hydrogen breath tests in children with suspected carbohydrate malabsorption

Abstract

Background: Hydrogen breath tests are noninvasive procedures frequently applied in the diagnostic workup of functional gastrointestinal disorders. Here, we review hydrogen breath test results and the occurrence of lactose, fructose and sorbitol malabsorption in pediatric patients; and determine the significance of the findings and the outcome of patients with carbohydrate malabsorption.

Methods: We included 206 children (88 male, 118 female, median age 10.7 years, range 3-18 years) with a total of 449 hydrogen breath tests (lactose, n = 161; fructose, n = 142; sorbitol, n = 146) into a retrospective analysis. Apart from test results, we documented symptoms, the therapeutic consequences of the test, the outcome and the overall satisfaction of the patients and families.

Results: In total, 204 (46%) of all breath tests were positive. Long-term follow-up data could be collected from 118 patients. Of 79 patients (67%) who were put on a diet reduced in lactose, fructose and/or sorbitol, the majority (92%, n = 73) reported the diet to be strict and only 13% (n = 10) had no response to diet. Most families (96%, n = 113) were satisfied by the test and the therapy. There were only 21 tests (5%) with a borderline result because the criteria for a positive result were only partially met.

Conclusions: Hydrogen breath tests can be helpful in the evaluation of children with gastrointestinal symptoms including functional intestinal disorders. If applied for a variety of carbohydrates but only where indicated, around two-third of all children have positive results. The therapeutic consequences are successfully relieving symptoms in the vast majority of patients.

Figure 1

Performance of the hydrogen breath tests at different hydrogen cut-offs. Percentage of positive, negative and borderline hydrogen breath test results by three different hydrogen breath cut-offs as indicated. An increase in the production of hydrogen ≥20 (≥15; ≥25) ppm and a two-fold increase of the individual baseline H₂-exhalation in three consecutive breath samples was considered positive. Breath test, in which three hydrogen values were ≥20 (≥15; ≥25) ppm but not all of those topped the baseline value by a two-fold increase or where hydrogen levels reached at least 20 (≥15; ≥25) ppm but not at three time points were considered as borderline. All other test results were classified as being negative.

Figure 2

Time course analysis of hydrogen concentrations during breath tests. Comparison of the rise in breath hydrogen over time after ingestion of test meal in patients with positive and negative results of hydrogen breath tests with lactose (A), fructose (B), and sorbitol (C). Tracing of breath hydrogen excretion is expressed as mean ± SEM.