NNNS: Diabetes and Glycemic Response (2011)
- No renal failure
- None suffered any acute illness for more than one week during the study or during the last week of each dietary period.
- Study approved by the Research Advisory and Ethics Committee of Prince Henry's Hospital. Ten subjects were taking sulphonylueas and one subject was also taking biguanide. Three were taking anti-hypertensive medication and two patients were on diuretics. All drug therapy remained constant throughout the study.
- Crossover design and patients were randomly allocated to each six-week dietary sequence (11 were assigned to the sucrose diet first and six to the saccharin diet first).
- Dietary prescription: High carbohyrate (50% of energy) and low fat (30% of energy), the usual diet of each patient was supplemented daily with either 28g of sucrose (sucrose diet) or saccharin and starch (saccharin). Saccharin and starch supplements were equivalent to about 28g of sucrose in sweetness and energy.
- The supplements were divided among three main meals and sucrose, an evening supper. The foods to which the supplements were added were hot beverages, fruit juice, milk, cereals and stewed fruit.
- Standard breakfast: Cereal, whole milk, wholemeal bread, polyunsaturated margarine and tea, coffee or water, to which either 8g sucrose or a one-gram saccharin tablet plus 10g corn flour were added. The test meals provided 1.5mj (15% protein, 33% fat, 52% carbohydrate, 3.3g fiber). The sucrose supplement was the sole source of sucrose in the test meal and it represented 8.2% of the total meal energy.
- All meal studies commenced between 8:30 a.m. and 10:00 p.m. The time taken for each meal was kept constant for each patient, which ranged between eight and 15 minutes.
- All results expressed as mean and 95% confidence interval
- Statistical comparison was by two-way analysis of variance.
Timing of Measurements
- Food records were kept throughout the study
- Patients were visited weekly for delivery of supplements, weight recordings and encouragement of compliance. At the beginning and end of each dietary period, they visited the hospital on two consecutive mornings for metabolic assessment, with the test meals given in random order.
- Test meals: Patients fasted overnight and rested thoughout the experimental period
- Baseline fasting blood samples were taken at 10 minutes before, immediately before and at regular intervals (over three hours) after consumption of the test meal
- Systolic and diastolic pressure: Recorded prior to each meal study using a blood pressure monitor. Standardized conditions, patient fasted and had rested for 10 to 15 minutes. Consecutive readings were taken over five minutes and the mean of the three readings was recorded.
- Four-hour urine collections: Done on consecutive days, at the beginning of the study and at the end of each dietary period before the test meal; for determination of sodium, potassium and glucose excretion.
- Initial N: 17 non-insulin dependent diabetic volunteers (11 females, six males)
- Age: 62.2±14.0
- Anthropometrics: BMI 26.0±3.0kg/m2; fasting blood glucose 8.9±2.8mmol/L-1.
Neither the sucrose diet nor the sachharin diet resulted in a significant change in fasting concentration of blood glucose (P>0.25), plasma insulin (P>0.10), serum triglyceride (P>0.25) or HDL cholesterol (P>0.25), when compared with present study levels.
Metabolic and Blood Pressure Control in 17 Patients with Type 2 Diabetes at the Three Stages of the Study
|Pre-Study||Sucrose Diet||Saccharin Diet|
|Weight (kg)||69.1 (65.4-72.8)||69.3 (65.2-72.9)||68.9 (64.9-72.7)|
|Fasting Blood Glucose (mmol/L-1)||8.9 (7.5-10.2)||9.2 (7.9-10.7)||8.9 (7.4-10.4)|
|Fasting Plasma Insulin (mUL-1)||14.4 (10.9-17.8)||16.5 (12.7-20.2)||17.3 (13.9-20.6)|
|Glycosylated Haemoglobin (%)||8.1 (7.3-8.9)||6.8 (6.2-7.3)a||8.0 (7.5-8.5)|
|Glucose Excretion (mmol 24 h-1)||91 (0-197)||121 (0.0-266)||117 (0.0-251)|
|Fasting Triglycerides (mmol L-1)||2.0 (1.6-2.4)||2.0 (1.6-2.5)||2.0 (1.6-2.5)|
|Fasting Total Cholesterol (mmol L-1)||6.2 (5.7-6.7)||5.8 (5.4-6.2)b||5.8 (5.3-6.3)b|
|Fasting LDL Cholesterol (mmol L-1)||4.10 (3.64-4.56)||3.75 (3.32-4.12)b||3.78 (3.32-4.24)b|
Fasting HDL Cholesterol (mmol L-1)
|1.10 (0.91-1.27)||1.08 (0.92-1.24)||1.06 (0.90-1.22)|
|Systolic Blood Pressure||139 (131-146)||131 (125-138)b||132 (126-138)b|
|Diastolic Blood Pressure||81 (77-86)||76 (72-80)b||75 (70-80)b|
|Na+Excretion (mmol 24 h-1)||164 (133-196)||131 (107-155)||144 (116-172)|
|K+Excretion (mmol 24 h-1)||64 (53-75)||61 (51-71)||58 (46-68)|
Mean 95% confidence limits
A: Significantly lower than pre-study (P<0.01)
B: Significantly lower than pre-study (P<0.05).
- There was no significant difference in serum cholesterol between the two diets (P>0.25)
- Glycosylated hemoglobin was significantly lower after the sucrose diet (P<0.01), but not significantly different after the saccharin diet (P>0.25)
- There was no significant effect of either diet on the blood glucose or plasma insulin responses to the two test meals (P>0.25)
- Systolic and diastolic blood pressure were significantly greater at the start of the study than after each diet (P<0.05), but there was no difference in blood pressure between diets (P>0.25)
- Neither diet significantly affected sodium (P<0.10), potassium (P>0.25) or glucose excretion (P>0.10).
- Biases: Studies have found that uncooked starch causes a lower post-prandial response than cooked starch. Therefore, since in this study the starch supplement was uncooked (raw) corn flour, this may have effected any differences from appearing between the two test meals.
- Following a standard breakfast with either sucrose or saccharin and starch, no differences in meal responses were observed
- The study demonstrated no medium-term metbolic contraindications for including a moderate amount of sucrose in the diets of patients with non-insulin-dependent diabetes mellitus.
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?||No|
|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?||Yes|
|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?||Yes|
|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")?||Yes|
|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%.)||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.)||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?||No|
|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)?||N/A|
|8.5.||Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?||Yes|
|8.6.||Was clinical significance as well as statistical significance reported?||No|
|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?||N/A|
|10.1.||Were sources of funding and investigators' affiliations described?||Yes|
|10.2.||Was the study free from apparent conflict of interest?||Yes|