title: Inverse dose effect of pretest dietary lactose intake on breath hydrogen results and symptoms in lactase nonpersistent subjects.
abstract: The aim of this study was to determine a relationship between pretest intake of lactose and outcome of lactose breath hydrogen test. Patients presented at a testing laboratory participated in the study. A 3-hour breath hydrogen, 50-g lactose challenge was carried out. Results were tabulated and patients completed a 3-day recall diet questionnaire. Daily lactose intake was independently calculated and was associated with breath hydrogen and total symptom score. Statistical analysis used Spearman's correlation, Mann-Whitney U-test and chi2 or Fisher exact test. Of 118 patients, 50% were lactose maldigesters. In these patients, measured breath hydrogen and symptom scores were significantly higher in the lowest intake group (< 5 g/d) than in the highest intake group (> 20 g/d) (P < .05). In the presumed lactose digesters, 59% experienced some symptoms during testing for unclear reasons. Pretest dietary intake of lactose inversely affects results of breath hydrogen.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Sir Mortimer B. Davis--Jewish General Hospital, McGill University, Montreal, Quebec, Canada. aszilagy@gas.jgh.mcgill.ca
authors.forename: Andrew
authors.initials: A
authors.lastname: Szilagyi
authors.forename: Paula
authors.initials: P
authors.lastname: Malolepszy
authors.forename: Samara
authors.initials: S
authors.lastname: Yesovitch
authors.forename: Usha
authors.initials: U
authors.lastname: Nathwani
authors.forename: Christina
authors.initials: C
authors.lastname: Vinokuroff
authors.forename: Albert
authors.initials: A
authors.lastname: Cohen
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Xue
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001944:Breath Tests / Q000379:methods*; D004032:Diet; D005260:Female; D006801:Humans; D006859:Hydrogen / Q000032:analysis / Q000378:metabolism*; D043322:Lactase / Q000378:metabolism*; D007785:Lactose / Q000008:administration & dosage* / Q000494:pharmacology*; D007787:Lactose Intolerance / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D006859:Hydrogen; D043322:Lactase; D007785:Lactose