Hydrogen Breath Test for Diagnosis of Lactose Malabsorption: The Importance of Timing and the Number of Breath Samples

Abstract

Hydrogen breath test for diagnosis of lactose malabsorption: The importance of timing and the number of breath samples. Can J Gastroenterol 2006;20(4):265-268. BACKGROUND:The hydrogen breath test (H 2 BT) is the most widely used procedure in the diagnostic workup of lactose malabsorption and lactose intolerance. AIM: To establish whether a simplified two-or three-sample test may reduce time, costs and staff resources without reducing the sensitivity of the procedure. PATIENTS AND METHODS: Data from 1112 patients (292 men, 820 women) with a positive 4 h, nine-sample H 2 BT were retrospectively analyzed. Patients were stratified according to the degree of lactose malabsorption, the occurrence and type of symptoms. Loss of sensitivity in the procedure was evaluated taking into account two-sample tests (0 min and 120 min or 0 min and 210 min) or three-sample tests (0 min, 120 min and 180 min or 0 min, 120 min and 210 min). RESULTS: Using a two-sample test (0 min and 120 min or 0 min and 210 min) the false-negative rate was 33.4% and 22.7%, respectively. With a three-sample test (0 min, 120 min and 180 min or 0 min, 120 min or 210 min), lactose malabsorption was diagnosed in 91.2% (1014 of 1112) patients and in 96.1% (1068 of 1112) patients, respectively. Of 594 patients with abdominal symptoms, 158 (26.6%) and 73 (12.2%) would have false-negative results with 0 min and 120 min or 0 min and 210 min two-sample tests, respectively. The three-sample tests, 0 min, 120 min and 180 min or 0 min, 120 min and 210 min, have a false-negative rate of 5.9% and 2.1%, respectively. CONCLUSIONS: A three-sample H 2 BT is time-and cost-sparing without significant loss of sensitivity for the diagnosis both of lactose malabsorption and lactose intolerance.

Fructose and lactose intolerance and malabsorption testing: the relationship with symptoms in functional gastrointestinal disorders

“…It should be noted that the relationship between symptom induction, and therefore intolerance rates, and malabsorption is dependent on the choice of symptom scoring, with a positive association between the number and intensity of induced symptoms and the percentage of positive hydrogen breath tests following lactose having been shown . In this study, a sensitive symptom index reflecting both intensity and symptom number was used very similar to the 9‐item validated score used by Choi et al ., with intolerance rates not greater than in other large comparative studies in Caucasians for lactose – we are not aware of any similar large studies for fructose intolerance . Only a small minority of these referred patients were able to correctly identify their food intolerance before the provocation testing, but this undoubtedly also partly reflects a referral bias to a GI practice.…”

“…Furthermore, the correlation between clinical symptoms and those experienced during breath testing is an important confirmation for the patient. A breath collection duration longer than 3 h has been recommended in previous studies for improved diagnostics of lactose intolerance …”

Frequency of lactose malabsorption among healthy southern and northern Indian populations by genetic analysis and lactose hydrogen breath and tolerance tests

“…Methods used to evaluate LM include the lactose hydrogen breath test (HBT) (17)(18)(19)(20), the lactose tolerance test (LTT) (21,22), estimation of lactase concentrations in intestinal biopsy samples, and genetic tests (23). Recent studies have shown that the single nucleotide polymorphism (SNP) at position 13910 nucleotide upstream to the gene coding for lactase on chromosome-2 (LCT locus) determines the LP/LNP status (23).…”

Diagnosing lactase deficiency in three breaths

“…In a similar study design to ours, Di Camillo et al (2006) evaluated the implications of simplifying a 4-h 30-min breath sampling lactose H 2 -BT in a large group of patients. The authors concluded that the H 2 -BT could be effectively performed with only three breath samples (0, 120 and 180 min) without a relevant loss of sensitivity (94.1%).…”