A comparison of diagnostic tests for lactose malabsorption - which one is the best?

Abstract

BackgroundPerceived milk intolerance is a common complaint, and tests for lactose malabsorption (LM) are unreliable. This study assesses the agreement between diagnostic tests for LM and describes the diagnostic properties of the tests.MethodsPatients above 18 years of age with suspected LM were included. After oral intake of 25 g lactose, a combined test with measurement of serum glucose (s-glucose) and hydrogen (H2) and methane (CH4) in expired air was performed and symptoms were recorded. In patients with discrepancies between the results, the combined test was repeated and a gene test for lactose non-persistence was added. The diagnosis of LM was based on an evaluation of all tests. The following tests were compared: Increase in H2, CH4, H2+CH4 and H2+CH4x2 in expired air, increase in s-glucose, and symptoms. The agreement was calculated and the diagnostic properties described.ResultsSixty patients were included, seven (12%) had LM. The agreement (kappa-values) between the methods varied from 0.25 to 0.91. The best test was the lactose breath test with measurement of the increase in H2 + CH4x2 in expired air. With a cut-off level < 18 ppm, the area under the ROC-curve was 0.967 and sensitivity was 100%. This shows that measurement of CH4 in addition to H2 improves the diagnostic properties of the breath test.ConclusionThe agreement between commonly used methods for the diagnosis of LM was unsatisfactory. A lactose breath test with measurement of H2 + CH4x2 in expired air had the best diagnostic properties.

β-thalassemia minor, carbohydrate malabsorption and histamine intolerance

“…The hydrogen breath test (Gastrolyzer, Bedfont Scientific Inc., Kent, England) was performed with a drink containing 50 g lactose dissolved in 200 ml water, the end-expiratory exhalation of H2 was measured every 30 min for a period of 150 min. The result was an H2-value increasing from the baseline 9 up to 130 parts per million (ppm) (normal: <20) [4]. An additionally performed lactase gene (LCT) C/T-13910 polymorphism genotyping revealed the congenital lactase deficiency C/C genotype (Amplifluor Genotyping System, Chemicon, Merck, Germany).…”

“…All the other routine laboratory parameters were within normal limits. During the breath test with a drink containing 50 g lactose, the end-expiratory exhalation of H2 was <20 ppm [4]. Antibodies against tissue transglutaminase were not found, and a gastroscopy with biopsies was negative for Helicobacter pylori infection or other abnormality.…”

Milk Consumption is Not Affected by C/T-13910 Single Nucleotide Polymorphism in a Tajik Population in a Southern Region of Uzbekistan

“…Importantly, genotyping is a minimally invasive method and the results of the tests are available quickly [19,20].…”

Ingestão de cálcio e densidade mineral óssea em mulheres adultas intolerantes à lactose

“…Entretanto, a capacidade de digerir a lactose contida no leite depende da presença e da atividade da enzima lactase 2,3 , cuja atividade diminui com o passar dos anos devido a uma redução na sua quantidade no intestino, ocasionando a má-absorção da lactose [4][5][6] . Na maior parte da população mundial, após o desmame, há um declínio gradual na atividade da lactase, um fenômeno denominado hipolactasia.…”