DM: Carbohydrates (2007)
To examine the effects of replacing 30g of complex carbohydrate of high glycemic index with an equal amount of sucrose in a high-carbohydrate high-fiber diet in type 1 diabetic patients.
Recruitment: Methods not described
Design subjects followed two diets, in random order, each for two months
Blinding used (if applicable): not possible
Intervention (if applicable)
- Control diet: 17% protein, 31% fat, and 52% carbohydrate
- Sucrose diet: same diet with 30g of complex carbohydrate (bread) replaced by sucrose; sucrose could be added to foods as a sweetener or sucrose-containing foods could be consumed
- subjects lived at home and planned their own meals using exchange lists
Statistical Analysis
Student's t-test for paired samples.
Timing of Measurements Lab measurements taken at the beginning and end of each diet period.
Dependent Variables
- HbA1c, by column chromatography
- fructosamine
- mean blood glucose, mean of 20 assays in 5 consecutive days of blood glucose monitoring, using reflectometer
- total and HDL-cholesterol
- incidence of hypoglycemic episodes
Independent Variables
- Control diet: 17% protein, 31% fat, and 52% carbohydrate
- Sucrose diet: same diet with 30g of complex carbohydrate (bread) replaced by sucrose; sucrose could be added to foods as a sweetener or sucrose-containing foods could be consumed
- subjects lived at home and planned their own meals using exchange lists
- dietary adherence was assessed by dietitian from 3-day food diary at two-week intervals
- subjects instructed to weigh or measure food
Control Variables
Initial N: 12; 6 women
Attrition (final N): 12
Age: 16-46 yrs
Ethnicity: not specified
Other relevant demographics: duration of disease 5 - 23 years
Anthropometrics BMI range 19.8 - 25.0
Location: Italy
Variables |
Control Diet, at 2 months |
Sucrose Diet, at 2 months |
Statistical Significance of Group Difference |
HbA1c |
6.8±0.2 | 6.9±0.4 | P>0.4 |
fructosomaine, mmol/l |
3.7±0.2 |
3.5±0.1 |
P>0.4 |
mean blood glucose, mg/dl |
164±18 |
167±16 |
P>0.4 |
Total cholesterol, mg/dl | 202±16 | 212±9 | P>0.4 |
HDL, mg/dl | 58±0.2 | 52±4 | P>0.4 |
triglycerides, mg/dl | 63±0.2 | 76±12 | P>0.4 |
Other Findings
Mean daily insulin dose, incidence of hypoglycemic episodes and body weight were the same for both groups.
University/Hospital: | Cliniques Univeritaires (Italy) |
The age range of participants was broad, including at least one teenager.
No p values for statistical significance was given in advance of statistical analysis. P values greater than 0.4 were noted in the study.
Blood glucose values were derived from 20 self-monitoring tests over 5 consecutive days. Self-monitoring is not free from bias.
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? | 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? | Yes | |
2.4. | Were the subjects/patients a representative sample of the relevant population? | No | |
3. | Were study groups comparable? | N/A | |
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? | N/A | |
3.3. | Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) | N/A | |
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? | 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.) | No | |
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? | N/A | |
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? | ??? | |
7.6. | Were other factors accounted for (measured) that could affect outcomes? | No | |
7.7. | Were the measurements conducted consistently across groups? | N/A | |
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)? | 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? | No | |
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 | |