EAL

DF: Obesity (2008)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To measure the effect chitosan formulation on gastrointestinal fat absorption.

Inclusion Criteria:

Normal healthy subjects.

Exclusion Criteria:

Not described.

Description of Study Protocol:

Recruitment: Not described
Design: Double-blind, placebo-controlled crossover study
Blinding used: Participants received either active formulation or placebo pills.

Intervention

Group I: (Fiber then Placebo)
- Part A
  - Days One through Three: Fat-controlled diet (35% fat, 80g)
  - Days Four through Five: Fat-controlled diet and fecal fat collection
  - Days Six through Eight: Fat-controlled diet and chitosan and psyllium husk seed (Fat Trapper Plus)
  - Days Nine through 10: Fat-controlled diet and fecal fat collection
  - Days 11 through 14: Washout.
- Part B
  - Days 15 through 17: Fat-controlled diet (35% fat, 80g)
  - Days 18 through 19: Fat-controlled diet and fecal fat collection
  - Days 20 through 22: Fat-controlled diet and placebo
  - Days 23 through 24: Fat-controlled diet and fecal fat collection.
Group II: (Placebo then Fiber)
- Part A
  - Days One through Three: Fat-controlled diet (35% fat, 80g)
  - Days Four through Five: Fat-controlled diet and fecal fat collection
  - Days Six through Eight: Fat-controlled diet and placebo
  - Days Nine through 10: Fat-controlled diet and fecal fat collection
  - Days 11 through 14: Washout.
- Part B
  - Days 15 through 17: Fat-controlled diet (35% fat, 80g)
  - Days 18 through 19: Fat-controlled diet and fecal fat collection
  - Days 20 through 22: Fat-controlled diet and chitosan and psyllium husk seed (Fat Trapper Plus)
  - Days 23 through 24: Fat-controlled diet and fecal fat collection.
Subjects consumed a 35%-fat diet throughout the study and kept a food diary
Fiber supplements contained 2,100mg chitosan and 300mg psyllium husk and six capsules were consumed three times daily 10 minutes before meals
Stool samples were collected for 48 hours by patients.

Statistical Analysis

Means ± standard deviation
Paired two-tailed T-test: Differences between baseline and the experimental periods in Groups I and II
Unpaired T-test: Comparisons of the differences between the test and placebo groups
Analyses repeated among 19 individuals completing entire intervention
P<0.05 considered significant.

Data Collection Summary:

Timing of measurements: Stool samples collected Days Four to Five, Nine to 10, 18 to 19 and 23 to 24
Dependent variables: Fecal fat content
Independent variables: Fiber supplement, 2,100mg chitosan and 300mg psyllium husk
Control variables: None.

Description of Actual Data Sample:

Initial N: 29 (19 female, 10 male)
Attrition (final N): 10 (19)
Age
- Group I, 34.7±9.9
- Group II, 33.9±10.0.
Ethnicity: Not described
Other relevant demographics: Not described
Anthropometrics: Not described
Location: Not described.

Summary of Results:

Total Average Fecal Fat (Grams per Day), 48-Hour Collection in Parts A and B

Part A			Part B
Group	Baseline	Experimental	Group	Baseline	Experimental
I (Active)	4.7±3.0 (N=15)	8.2±4.8 (N=15)**	I (Placebo)	6.2±3.3 (N=10)	6.4±3.4 (N=10)
II (Placebo)	5.5±4.3 (N=11)	5.1±3.7 (N=11)	II (Active)	5.7±1.9 (N=9)	9.6±4.3 (N=9)*

* P<0.05, compared to baseline
** P<0.02, compared to baseline.

Other Findings

Fecal fat excretion increased over baseline following fiber supplement; 3.6g per day ±0.8 (SEM) vs. -0.2g per day ±0.9 (SEM), P=0.004.

Author Conclusion:

The weight-losing effects previously reported for the fiber chitosan cannot be attributed entirely to fat trapping
Findings demonstrate that oral supplementation of chiosan formulation can enhance fecal fat exretion in humans [by three to four grams per day].

Funding Source:

Industry:

Enforma Natural Products

Pharmaceutical/Dietary Supplement Company:

Reviewer Comments:

Poor description of eligibility criteria and study population
Primary analysis of crossover trial should be a within-subject comparison of end of treatment effects, not a between-group comparison
10 of 29 subjects did not complete intervention: Some due to lack of compliance, others due to side effects
Poor description of compliance to prescribed diet, intervention and fecal collection
Funded by Enforma.

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?	No
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?	N/A
	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?	???
3.	Were study groups comparable?		No
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	No
	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?	Yes
	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%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	No
	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.)	Yes
	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?		No
	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?	No
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	No
	6.6.	Were extra or unplanned treatments described?	No
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	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?		No
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	No
	8.2.	Were correct statistical tests used and assumptions of test not violated?	No
	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)?	No
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	No
	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?		No
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	No
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes