Search

Background and Study Aims: Lactase non-persistence (LNP), or primary hypolactasia, is a genetic condition that mediates lactose malabsorption and can cause lactose intolerance. Here we report the prevalence of lactose intolerance in a double-blind placebo study. Methods: The LCT C>T-13910 variant was genotyped by RT-PCR in 121 volunteers and lactose malabsorption was assessed using the hydrogen breath test (HBT) after consuming 25 g of lactose. Lactose intolerance was assessed by scoring symptoms (SS) using a standardized questionnaire following challenge with a lactose solution or saccharose placebo. Results: The LNP genotype was observed in 57% of the volunteers, among whom 87% were HBT(+). In the HBT(+) group the median SS was 9 and in the HBT(-) group the median SS was 3 (p < 0.001). No difference was observed in the SS when both groups were challenged with the placebo. The most common symptoms included audible bowel sounds, abdominal pain and meteorism. In the ROC curve analysis, an SS ≥6 demonstrated 72% sensitivity and 81% specificity for predicting a positive HBT. To estimate prevalence, lactose intolerance was defined as the presence of an SS ≥6 points after subtracting the placebo effect and 34% of the study population met this definition. Conclusions: The LNP genotype was present in more than half of subjects evaluated and the observed prevalence of lactose intolerance was 34%. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background and Aims: Patients with chronic inflammatory bowel disease (IBD) might have a higher prevalence of fructose malabsorption than healthy controls. This study's aim was to determine the prevalence and symptom severity of fructose malabsorption in patients with active and inactive IBD. Methods: The present study was a multicenter noninterventional diagnostic pilot trial. Two hundred fifty-one participants were recruited from 12 outpatient clinics for internal medicine across Germany and from the University of Kiel. Fructose malabsorption was diagnosed by hydrogen breath testing. Patients diagnosed with bacterial overgrowth, non-H2 producers, and patients who were tested positive for lactose malabsorption were excluded. Gastrointestinal symptoms during breath testing were evaluated using four-point subjective items to determine severity of bloating, abdominal pain, and diarrhea. Results: Two hundred five patients (45 with active IBD, 80 with IBD in remission, and 81 healthy controls) were analyzed. The number of patients diagnosed with fructose malabsorption – 35/44 (79.6%) in patients with active IBD, 59/80 (73.8%) inactive IBD, and 66/81 (81.5%) in healthy controls – did not differ between the groups (χ2 [2, N = 205] = 1.48, p = 0.48). However, abdominal pain was more frequent in patients with active IBD than patients with IBD in remission (z = −2.936, p = 0.010), and diarrhea was more frequent in patients with active IBD than in healthy controls (z = 2.489, p = 0.038). Conclusions: Fructose malabsorption is not more common among patients with IBD than healthy subjects. However, the greater prevalence of patient-reported symptoms among patients with IBD may be of pathological and therapeutic relevance. [ABSTRACT FROM AUTHOR]

Background/Aims: While lactose malabsorption is a well-investigated condition, few epidemiologic data are available for fructose and sorbitol malabsorption. The aim of this study was to assess the prevalence rates for primary lactose malabsorption, fructose and sorbitol malabsorption, and carbohydrate-specific small intestinal bacterial overgrowth (cs-SIBO) in an Austrian outpatient center. Methods: In total, 306 adult patients, who were primarily referred with suspected carbohydrate malabsorption by general practitioners to our outpatient clinic, underwent genetic testing (C/T-13910 polymorphism) for primary lactose malabsorption, and a combined hydrogen (H2)/methane (CH4) breath test for fructose (25 g) and sorbitol (12.5 g) malabsorption. Cohen's kappa (κ) was calculated for agreement between positive breath test results and self-reported symptoms during the test. Results: Seventy-eight (25.49%) patients were C/C-13910 homozygotes, indicating primary lactose malabsorption. Thirty-four (11.11%) and 57 (18.63%) patients were classified as fructose and sorbitol malabsorbers. Cohen's κ measuring agreements between positive fructose and sorbitol breath test results and self-reported symptoms during the test were 0.33 and 0.49, respectively. Twenty-nine (9.50%) patients with an early H2/CH4 peak (i.e. within 60 minutes after fructose and/or sorbitol ingestion) were diagnosed with cs-SIBO. Conclusion: In Austria, carbohydrate malabsorption is a frequent condition in patients referred by general practitioners to carbohydrate malabsorption testing. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background/Aims: The aim of the study is to investigate the frequency of pathological hydrogen breath tests (HBT) in patients with clinical features of functional dyspepsia (FD) meeting the Rome criteria and normal testing of upper endoscopy and abdominal sonography. Methods: We retrospectively included patients who underwent HBT (lactose, fructose, or glucose) between 2006 and 2012 and who had symptoms of FD. Patients were divided into 2 groups according to medical history and diagnostic results: (I) patients with suspected FD according to the Rome III criteria and (II) patients with an alternative diagnosis such as gastroesophageal reflux disease (GERD) or Crohn's disease (CD). Results: A total of 207/404 patients were assigned to the FD group and 44.4% of these had at least 1 positive HBT and thus more frequently than patients with GERD (20.7%; n = 111; p < 0.001) and with CD (31.7%; n = 63; p = 0.07). Lactose and fructose HBT, but not glucose HBT, occurred significantly more frequently with pathological results than in patients with GERD (p = 0.02; p = 0.002). The probability of a positive HBT increased significantly with increasing number of performed HBT (p < 0.001). Conclusion: We suggest that HBT should be considered in the clinical management of patients with suspected FD. In cases of positive HBTs, a potential causal therapy can be initiated. [ABSTRACT FROM AUTHOR]