DF: Diabetes (2008)
Karlstrom B, Vessby B, Asp NG, Ytterfors A. Effects of four meals with different kinds of dietary fibre on glucose metabolism in healthy subjects and non-insulin-dependent diabetic patients. Eur J Clin Nutr. 1988 Jun; 42 (6): 519-526.
PubMed ID: 2842146
To investigate the effects of a change from a low-fiber meal to a meal with an increased content of dietary fiber among both healthy women and women with diabetes.
Not described.
Not described.
- Recruitment: Not described
- Design: Control meal and three test meals were given in random order to each participant after an overnight fast. The test meals were separated by at least a day and not more than two test meals were eaten every week.
- Blinding used: Not described, but objective outcome (biochemical measures).
Intervention
- Meal A: Low-fiber (white bread, coffee, beef, potatoes, onion, tomatoes, parsley, margarine and apple juice)
- Meal B: High-fiber cereals (crisp bread, whole-meal wheat bread, wheat bran, coffee, beef, potatoes, onion, tomatoes, parsley, margarine and apple juice)
- Meal C: High-fiber from legumes (green beans, dried white beans, bouillon powder, coffee, beef, potatoes, onion, tomatoes, parsley, margarine and apple juice)
- Meal D: High-fiber from (crisp bread, dried white beans, bouillon powder, coffee, beef, potatoes, onion, tomatoes, parsley, margarine and apple juice).
Statistical Analysis
- Areas of deviation in the curve from fasting values over time (blood glucose and serum insulin)
- ANOVA
- Models of blood glucose, insulin, lipids
- Factors: Patient, meal, time point and meal x time-point interaction.
- Models of body weight, glucose and insulin areas of deviation
- Factors: Group, patient (nested within group) and group x meal interaction.
- Models of blood glucose, insulin, lipids
Dependent Variables
- Blood samples for glucose and insulin: Fasting, 20, 30, 60, 90, 120, 180 and 240 minutes after the meal
- Basal glucose and insulin: Mean values of two measurements during fasting before the meals
- Blood glucose: Measured by glucose oxidase method
- Serum insulin: Measured by Phadesbas Insulin
- TG and HDL: Measured 60 and 250 minutes post-meal, by enzymatic methods.
Independent Variables
- Starch
- Sucrose
- Glucose
- Fructose
- Total fat
- Fiber content.
Control Variables
N/A.
- Initial N: 12 healthy women, 13 women with diabetes
- Attrition (final N): Not described.
Age
- Healthy women: Mean, 63 years (range, 53 to 77 years)
- Women with diabetes: Mean, 64 years (range, 54 to 70 years).
Ethnicity
Not reported.
Other Relevant Demographics
Eight women with diabetes treated with oral medication: Nine had diabetes for more than five years; two for more than one year; two for six months.
Anthropometrics
- Healthy women: Mean BMI, 24.5 (SEM, 0.9)
- Women with diabetes: Mean BMI, 25.7 (SEM, 1.1)
Location
Department of Geriatrics, Uppsala University, Sweden.
- Food analysis results
- For meals A, B and D, the deviation between the sum of analyzed digestible carbohydrates plus fiber and the carbohydrate by difference was only 5% to 7%
- The leguminous meal (C) was 20% lower than expected, due to lower digestible carbohydrate content.
- Blood glucose results
- In the healthy group, there were no significant differences between the control meal and the test meals or between the different test meals, with respect to blood glucose
- In the group with diabetes, the blood glucose was significantly lower after the leguminous and the mixed-fiber meal, compared with the control meal.
- Insulin results
- In the healthy group, insulin response was lower after the leguminous meal than the control
- In the group with diabetes, the insulin response was reduced after all test meals, compared with the control meal. The insulin responses after the three test meals did not differ.
- The content of digestible carbohydrate was lower in the high-fiber meals than the control meal
- There were no differences in triglycerides, serum cholesterol or HDL cholesterol after the test meals, compared to control between test meals, either in the healthy or diabetic group
- No differences in body weight or fasting insulin between the different days when the meals were eaten.
NIDDM patients should be recommended diets with an increased content of dietary fiber.
Government: | Swedish Medical Research Council | ||
Not-for-profit |
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- Description of recruitment and inclusion and exclusion criteria not mentioned
- Did not describe any dropouts; assumed no loss to follow-up
- Statistical analysis unclear.
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? | ??? | |
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? | Yes | |
2.4. | Were the subjects/patients a representative sample of the relevant population? | ??? | |
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) | Yes | |
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? | 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.) | 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? | 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? | Yes | |
6.6. | Were extra or unplanned treatments described? | Yes | |
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? | Yes | |
8.1. | Were statistical analyses adequately described and the results reported appropriately? | ??? | |
8.2. | Were correct statistical tests used and assumptions of test not violated? | ??? | |
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)? | N/A | |
8.6. | Was clinical significance as well as statistical significance reported? | N/A | |
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? | Yes | |
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 | |