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.
- 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).
- 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).
- Areas of deviation in the curve from fasting values over time (blood glucose and serum insulin)
- 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
- 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.
- Total fat
- Fiber content.
- Initial N: 12 healthy women, 13 women with diabetes
- Attrition (final N): Not described.
- Healthy women: Mean, 63 years (range, 53 to 77 years)
- Women with diabetes: Mean, 64 years (range, 54 to 70 years).
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.
- Healthy women: Mean BMI, 24.5 (SEM, 0.9)
- Women with diabetes: Mean BMI, 25.7 (SEM, 1.1)
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|
- 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
|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|
|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|