EAL

NNNS: Diabetes and Glycemic Response (2006)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To examine the sugar-fat relationship in a group of insulin-dependent diabetics who were recognized as high users of intense sweeteners and an age- and sex-matched group.

Inclusion Criteria:

Experimental group: Insulin dependence; 16 years to 75 years of age.
Control group: Age- (±5 years) and sex-matched.

Exclusion Criteria:

None noted.

Description of Study Protocol:

Recruitment

Experimental group recruited from outpatients' clinics (convenience sample)
Control group recruited from friends of the patients or staff and college students.

Design:

Food consumption data were collected via three-day food diaries.

Statistical Analysis

Parametric analyses were conducted on the normally distributed nutrient intake data
Nutrient intakes in each group were compared using independent tests
Participants in each group were divided into teritiles of energy percentage and two ANOVA were used
A one-way ANOVA was conducted for each group to examine intense sweetener intake.

Data Collection Summary:

Dependent Variables

Nutrient intake was measured by a validated three-day diary instrument completed by subjects on two weekdays and one weekend day
Over the whole sample, the beginning times for the subjects were spread out equally over the seven days of the week and over seasons
Subjects filled in the diary after each eating occasion and were told to maintain their usual eating habits
Researchers met with each subject to go through the previous three days' entries, checking food description, brands, ingredients of recipes and quantities and to identify possible omissions
Foods were coded and nutrient intakes determined using the computerized program WISP, version 1.27
Data coding and entry procedures were entered twice to ensure quality control.

Independent Variables

Intense sweetener intake: The Irish National Food Ingredient Database was used to determine the foods on the market containing intense sweetners
An intense sweetness intake index was developed for each subject, based on the Irish National Food Ingredient Database and the individual's food intake diary.

Description of Actual Data Sample:

Initial N: 119 people with diabetes, 119 age and sex matched controls.
Attrition (final N): There were 34 under-reporters in the diabetic group and 32 in the control group. Their data were not included in the final analyses.
Location: People with diabetes were recruited from diabetic outpatient departments of St. James's Hospital in Dublin, Ireland. Case-matched control subjects were recurited from friends and family of patients and from students of Trinity College and University College, Dublin.

Summary of Results:

Only statistically significant differences are reported for data other than demographic data.

Demographic Data	Diabetics (N=85) Mean ± Standard Deviation			Control Group Mean ± Standard Deviation			Statistical Significance of Group Difference
Age (years)	36.5±13.6			35.9±14.6			NS
Weight (kg)	74.5±13.6			71.5±13.3			NS
Height (kg)	1.7±0.1			1.7±0.1			NS
BMI (kg/m²)	26±4.1			24.6±3.6			0.02
Mean Daily Intakes
Percentage of energy from protein	16±3.7			14.4±2.8			0.002
Percentage of energy from starch	27.7±5.8			23.5±5.2			<0.001
Percentage of energy from sugars	15.8±6.9			20.8±8.8			<0.001
Percentage of energy starch: sugars	2.1±1.2			1.4±7.4			<0.001
Fiber (g)	27.7±9.5			21.8±7.4			<0.0001
Vitamin D (mcg)	4.6±2.9			3.5±2.2			0.003
Copper (mg)	1.5±0.6			1.28±0.4			0.006
Mean Daily Intakes Based on Tertiles of Percentage of Energy from Fat	Low (N=26)	Med (N=32)	High (N=27)	Low (N=27)	Med (N=29)	High (N=31)	ANOVA Fat Tertiles (P-values)
Percentage of Energy from Fat	28.6±2.7	36.2±1.4	42.8±3.6	28.2±2.8	35.3±1.4	42.0±3.4	<0.001
Percentage of Energy from Carbohydrate	48.1±7.6	43.0±5.2	39.7±5.5	49.5±10.5	43.5±6.9	39.0±4.7	<0.001
Percentage of Energy from Sugars	19.3±7.4	15.3±6.7	13.1±5.2	27.6±10.8	19.8±6.3	16.0±4.3	<0.001
Percentage of Energy from Alcohol	7.1±9.5	4.8±5.0	2.2±3.0	8.5±11.5	7.1±6.9	4.3±4.7	0.007
Percentage of Energy Starch:Sugars	1.8±0.9	2.3±1.4	2.3±1	1.1±0.9	1.4±0.7	1.6±0.5	0.007
Zinc (mg)	11.0±4.5	12.0±4.1	12.2±4.4	9.2±4.0	9.4±3.3	12.7 (no SD given)	0.008
Vitamin C (mg)	200.8±197.3	154.9±154.0	133.9±138.1	336.9±258.3	159.6±134.4	156.7±144.0	<0.001
Vitamin E (mg)	7.6±2.4	8.8±2.5	10.9±4.3	7.8±2.8	8.3±2.7	10.0±4.4	<0.001
Retinol (mcg)	545.9±580.6	575.1±203.6	907.2±713.2	351.4±168.2	455.1±171.5	802.9±682.6	<0.001
Mean Daily Intakes Based on Tertiles of Intense Sweeteners							ANOVA: Diabetic Tertiles (P-values)
Energy (mJ/day)	10.3±2.2	10.7±2.0	12.5±3.9				0.03

The total intense sweetness intake index showed that the diabetics had a much higher usage level of intense sweeteners, in comparison to controls (2.5 vs. 1.4/d, P=0.0001)
The direct comparison of the diets of the diabetics and controls, across tertiles of intense sweetness intake index, showed no differences in fat percentage energy, even though the diabetics had double the intake of the intense sweetness index. Even within groups, across tertiles of intense sweetness intake index, no evidence was found in this study that macronutrient intakes are significantly influenced.
In the diabetic group, as the intense sweetness intake index increased, the percentage of energy from sugars decreased and the percentage of energy from starch increased, but not significantly. In contrast, in the control group, as the intense sweetness intake index increased, the percentage of energy from sugars and the percentage of energy from carbohydrates increased.

Author Conclusion:

"The sugar-fat seesaw, previously observed in healthy subjects, is present but at a lower level in diabetics. No evidence has been produced in the present study to show that in a free-living population on a self-selected diet, intense sweetner intake influences macronutrient balance."

Funding Source:

University/Hospital:

Trinity College, Saint James Hospital, Dublin Institute of Technology (All Ireland)

Reviewer Comments:

Short study duration may limit the ability of a three-day diary to reflect long-term intake (although some studies have demonstrated the adequacy of short-duration food intake records for such a purpose)
In unblinded studies such as this, it is never possible to avoid the Hawthorne effect.

Quality Criteria Checklist: Primary Research
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)	N/A
	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)	N/A

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?	N/A
	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?	Yes
	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?		N/A
	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?	N/A
	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.)	Yes
	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?	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%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	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?		N/A
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	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.)	N/A
	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?	Yes
	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?		N/A
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	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?	N/A
	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?	No
	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?	???
	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)?	Yes
	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?	N/A
10.	Is bias due to study's funding or sponsorship unlikely?		No
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes