DF: Cardiovascular Disease (2008)
To examine the effects of fiber, in the form of guar preparations, on glycosylated hemoglobin, total cholesterol and triglycerides in individuals with diabetes.
- Diagnosis of diabetes mellitus
- Between the ages of 18 and 65
- Glycosylated hemoglobin greater than 10%.
Not described.
- Recruitment: Not described
- Design: Randomized controlled study of 40 diabetic patients to test two different guar preparations (four grams of GU-052, five grams Glucotard) before each meal (breakfast, lunch and dinner) for 12 weeks
- Blinding used: N/A.
Intervention
- Subjects were randomly assigned to consume either four grams of GU-052 with 200ml liquid before each meal or five grams Glucotard, given in the form of three spoonfuls, with 250ml liquid before each meal
- No new dietary advice or teaching was given during the 12 weeks
- Both groups continued their usual diets for the 12 weeks
- Laboratories were collected one month prior to the start of the study and at zero, 30, 60 and 90 days:
- Glycosylated hemoglobin
- Total cholesterol
- Triglycerides.
Statistical Analysis
- Paired non-parametric statistical tests
- Wilcoxon matched-sign rank test to measure progressive changes within each group
- P=0.05.
Timing of Measurements
Glycosylated hemoglobin, total cholesterol and triglycerides were collected at one month prior to the start of the study, 0, 30, 60 and 90 days.
Dependent Variables
- Glycosylated hemoglobin
- Total cholesterol
- Triglycerides.
Independent Variables
- Fiber intake
Initial N
- 40
- 29 males, 11 females
- 33 oral antidiabetic treatment
- Seven insulin-requiring.
Attrition (Final N)
Not described.
Age
- GU-052: 55.1±5.5 years
- Glucotard: 53.6±9.6 years.
Ethnicity
Not described.
Anthropometrics
No significant differences between the two groups could be established before therapy.
Location
University of Frankfort Medical Clinic, Frankfurt, Germany.
Glycosylated Hemoglobin
GU-052 guar preparation (N=19)
- Significantly lower following 30, 60 and 90 days of treatment
- Zero (12.6±2.6%)
- 30 (12.2±2.3%, P<0.05)
- 60 (10.8±8.3%, P<0.05)
- 90 (10.5±1.5%, P<0.05).
Glucotard guar preparation (N=21)
- Significantly lower following 30, 60 and 90 days of treatment
- Zero (12.0±2.6%)
- 30 (11.7±2.4%, P<0.05)
- 60 (11.2±2.1%, P<0.05)
- 90 (10.9±1.8%, P<0.05).
- HgbA1C significantly lower with GU-052 at 60 (P<0.02) and 90 (P<0.01) days
Total Cholesterol
GU-052 guar preparation (N=19)
- * Significantly lower following 90 days of treatment
- Zero (269±28mg/100ml)
- 30 (251±26mg/100ml)
- 60 (236±21mg/100ml)
- 90 (227±18mg/100ml, P<0.05).
Glucotard guar preparation (N=19)
- Significantly lower following 90 days of treatment
- Zero (261±39 mg/100ml)
- 30 (245±33 mg/100ml)
- 60 (239±25 mg/100ml)
- 90 (235±26 mg/100ml, P<0.05).
- Total cholesterol significantly lower with GU-052 at and 90 (P<0.02) days.
- The glycosylated hemoglobin and total cholesterol responses to the glucotard and GU-052 guar preparations were similar, producing significantly lower responses, compared to intial labs taken
- Using guar preparations as a fiber supplement may improve patient's blood glucose control and total cholesterol.
University/Hospital: | University of Frankfurt, University of Aechen (both Germany) |
- Small sample size, which is even smaller when broken down by type of DM
- No description of inclusion or exclusion criteria
- Limited presentation of demographic data
- Large difference in age between insulin and non-insulin requiring groups
- No power calculation presented
- No description of diet composition
- No data collected or presented on baseline (pre-meal) serum glucose or insulin levels
- No description of randomization scheme
- Limited description of guar preparation tolerance.
Quality Criteria Checklist: Primary Research
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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? | Yes | |
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? | N/A | |
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) | No | |
3.2. | Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? | Yes | |
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? | No | |
4.1. | Were follow-up methods described and the same for all groups? | No | |
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%.) | No | |
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? | No | |
5.1. | In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? | No | |
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? | Yes | |
6.1. | In RCT or other intervention trial, were protocols described for all regimens studied? | No | |
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? | N/A | |
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)? | Yes | |
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? | Yes | |
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? | No | |
10.2. | Was the study free from apparent conflict of interest? | Yes | |