EAL

NNNS: Polyols (2010)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine whether the malabsorbed sugars per se, the fermentation products or the intestinal distention changes the motor function of the gastrointestinal tract.

Inclusion Criteria:

Healthy subjects
Not taking antibiotics, laxatives or salicylates.

Exclusion Criteria:

Non-healthy subjects
Currently taking antibiotics, laxatives, or salicylates

Description of Study Protocol:

Design

Hydrogen and methane breath tests given
Subjects fasted overnight
Subjects ingested either 30g glucose or a mixture of 25g fructose and five grams sorbitol as 10% solutions
Mouth-to-cecum transit times of the test solutions were calculated as the interval between ingestion and the initial rise in breath hydrogen or methane concentration. A radio-labelled marker was used to follow the progress of the test solutions through the intestine.
Scintigraphy was used to follow the gastrointestinal transit of the test solutions
Breath hydrogen measurements and scintigraphy were done at 15-minute intervals for a six-hour period after ingestion of the test solution
During the measurements, subjects drank 200ml of water per hour
Subjects recorded and graded any gastrointestinal symptoms.

Blinding Used

Subjects had no information about the corresponding carbohydrate.

Statistical Analysis

Comparisons were done with non-parametric Wilcoxon signed rank test and Spearman rank correlation test.

Data Collection Summary:

Timing of Measurements

Breath hydrogen measurements and scintigraphy were done at 15-minute intervals for a six-hour period after ingestion of the test solution.

Dependent Variables

Variable One: Rise in hydrogen or methane from breath (breath test)
Variable Two: Solution gastrointestinal transit time (scintigraphy).

Independent Variables

Solution of glucose, fructose and sorbitol beverage.

Control Variables

Eating, smoking, sleeping and physical exercise were not allowed.

Description of Actual Data Sample:

Initial N: 11 (six women, five men)
Attrition (final N): 11 (six women, five men)
Age: Median, 27 (range, 26-48 years)
Ethnicity: Danish
Location: Copenhagen, Denmark.

Summary of Results:

Key Findings

No subject had greater than 10-ppm rise in breath hydrogen or methane concentration after ingestion of glucose
Malabsorption of the fructose-sorbitol mixture was revealed by hydrogen breath test in eight subjects and the methane test in the remaining three subjects
The mouth-to-cecum transit time was shorter (P=0.0033) and the amount of marker in the colon was higher at six hours (P=0.0128) in the fructose-sorbitol mixture than the glucose mixtue
No correlation was found between breath test and scintigraphic evaluations of mouth-to-cecum transit time of the fructose-sorbitol mixture.

Author Conclusion:

The accelerating effect of malabsorbed amounts of a fructose-sorbitol load on small intestinal transit may further decrease the absorption of the carbohydrates by reducing the small bowel mucosal contact time.

Funding Source:

University/Hospital:

University Hospital of Copenhagen, Denmark

Reviewer Comments:

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		No
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	No
	2.2.	Were criteria applied equally to all study groups?	No
	2.3.	Were health, demographics, and other characteristics of subjects described?	No
	2.4.	Were the subjects/patients a representative sample of the relevant population?	No
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	???
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	N/A
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	N/A
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	N/A
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	Yes
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	N/A
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	N/A
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	No
	10.2.	Was the study free from apparent conflict of interest?	Yes