Randomized Controlled Trial
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 14, 2015; 21(18): 5677-5684
Published online May 14, 2015. doi: 10.3748/wjg.v21.i18.5677
Self-reported dietary fructose intolerance in irritable bowel syndrome: Proposed diagnostic criteria
Leif Kyrre Berg, Erik Fagerli, Arnt-Otto Myhre, Jon Florholmen, Rasmus Goll
Leif Kyrre Berg, Erik Fagerli, Department of Medicine, Hospital of Helgeland, 8613 Nordland, Norway
Arnt-Otto Myhre, Laboratory of Gastroenterology, Institute of Clinical Medicine, Hospital of Nordland, 8005 Bodø, Norway
Leif Kyrre Berg, Jon Florholmen, Rasmus Goll, Research group of Gastroenterology and Nutrition, Institute of Clinical Medicine, University of Tromsø, 9038 Tromsø, Norway
Author contributions: Berg LK, Florholmen J, Fagerli E and Goll R contributed equally to this work; Berg LK and Florholmen J conceived and designed the project; Berg LK, Fagerli E, Myhre AO, Florholmen J and Goll R performed the data collection; Berg LK, Fagerli E, Florholmen J and Goll R analyzed data; Berg LK, Florholmen J and Goll R wrote the paper.
Supported by Northern Norway Regional Health Authority (Helse Nord RHF); Gastro Fund, University Hospital North Norway; and Helgeland Hospitals Research Committee.
Ethics approval: The study was reviewed and approved by Helse Nord RHF Institutional Review Board and approved by the Regional Ethical Committee of Northern Norway.
Clinical trial registration: The study was registered at www.clinicaltrials.gov (NCT00555191).
Informed consent: All study participants provided written consent prior to study enrollment.
Conflict-of-interest: The authors declare no conflict of interest.
Data sharing: The statistical methods of this study were reviewed by Rasmus Goll from University Hospital of Northern Norway and University of Tromsø. Technical appendix, statistical code, and dataset available from corresponding author at leif.kyrre.berg@online.no.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Leif Kyrre Berg, Department of Medicine, Hospital of Helgeland, Mo I Rana, 8613 Nordland, Norway. leif.kyrre.berg@online.no
Telephone: +47-77-626831 Fax: +47-77-626670
Received: October 31, 2014
Peer-review started: October 31, 2014
First decision: November 26, 2014
Revised: December 20, 2014
Accepted: January 30, 2015
Article in press: January 30, 2015
Published online: May 14, 2015
Processing time: 199 Days and 12.7 Hours
Abstract

AIM: To study the criteria for self-reported dietary fructose intolerance (DFI) and to evaluate subjective global assessment (SGA) as outcome measure.

METHODS: Irritable bowel syndrome (IBS) patients were randomized in an open study design with a 2 wk run-in on a habitual IBS diet, followed by 12 wk with/without additional fructose-reduced diet (FRD). Daily registrations of stool frequency and consistency, and symptoms on a visual analog scale (VAS) were performed during the first 4 wk. SGA was used for weekly registrations during the whole study period. Provocation with high-fructose diet was done at the end of the registration period. Fructose breath tests (FBTs) were performed. A total of 182 subjects performed the study according to the protocol (88 FRD, 94 controls).

RESULTS: We propose a new clinically feasible diagnostic standard for self-reported fructose intolerance. The instrument is based on VAS registrations of symptom relief on FRD combined with symptom aggravation upon provocation with fructose-rich diet. Using these criteria 43 of 77 patients (56%) in the present cohort of IBS patients had self-reported DFI. To improve the concept for clinical evaluation, we translated the SGA scale instrument to Norwegian and validated it in the context of the IBS diet regimen. The validation procedures showed a sensitivity, specificity and κ value for SGA detecting the self-reported DFI group by FRD response within the IBS patients of 0.79, 0.75 and 0.53, respectively. Addition of the provocation test yielded values of 0.84, 0.76 and 0.61, respectively. The corresponding validation results for FBT were 0.57, 0.34 and -0.13, respectively.

CONCLUSION: FRD improves symptoms in a subgroup of IBS patients. A diet trial followed by a provocation test evaluated by SGA can identify most responders to FRD.

Keywords: Breath test; Dietary restriction; Fructose malabsorption; Functional bowel disease; Sugar intolerance

Core tip: In this second report from the FINN study, new diagnostic criteria for self-reported fructose intolerance, based on fructose-reduced diet (FRD), were developed. Subjective global assessment of abdominal relief seems to be a valid outcome measure, which may be used as a feasible alternative to daily visual analog scale registrations both in daily routine handling of these patients and in future studies of irritable bowel syndrome (IBS). More than half of IBS patients in this study seemed to benefit from using FRD to control their IBS symptoms.