MNT: RDN in Medical Team (2015)

Citation:

Battista MC, Labonte M, Menard J, Jean-Denis F, Houde G, Ardilouze JL, Perron P. Dietitian-coached management in combination with annual endocrinologist follow up improves global metabolic and cardiovascular health in diabetic participants after 24 months. Appl Physiol Nutr Metab. 2012; 37 (4): 610-620.

PubMed ID: 22533481
 
Study Design:
Non-Randomized Controlled Trial
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

This study compared conventional care provided by endocrinologist alone over a 24 month period with the proposed dietitian-endocrinologist joint model.

Inclusion Criteria:

Participants were included in the study if they:

  • Had a diagnosis of type 2 diabetes mellitus
  • Had HbA1c over 7.0%
  • Had LDL-cholesterol over 2.0mmol per L
  • Had blood pressure above 130/80
  • Were taking blood pressure medication
  • Had triglycerides over 1.5mmol per L
  • Had an HDL-cholesterol ratio over 4.0.
Exclusion Criteria:

Participants were excluded if they were:

  • Pregnant
  • Receiving corticosteroids
  • Seen more than three times by their endocrinologist for extra follow-up care.
Description of Study Protocol:
  • Recruitment: Participants were recruited through the Diabetes Clinic at Centre Universitaire de Sherbrooke (CHUS) Fleurimont and Hotel-Dieu 
  • Design: Non-randomized controlled trial
  • Blinding used (if applicable): Implied with measurements.

Intervention

  • Conventional care provided by endocrinologist alone over a 24-month period
  • Proposed dietitian-endocrinologist joint model. Participants were seen every three months by the dietitian for 24 months. Participants received monthly phone calls from the dietitian between visits. The intervention consists of a physical activity recommendations using a questionnaire and pedometers. Participants were educated on the following nutrition behaviors:
    • Goal One: Appropriate portion sizes, carbohydrate counting and glycemic control
    • Goal Two: Avoid excessive energy intake using a food log to evaluate dietary compliance. 

Statistical Analysis

  • Distribution of continuous variables was assessed
  • Residual distribution was verified prior to repeated-measures analysis of covariance (ANCOVA)
  • If not normally distributed, non-parametrical analyses were performed and expressed as median (25th to 75th percentiles)
  • Baseline characteristics and outcome variables at 24 months were compared using student T-test or X2
  • Intra-group analyses were performed using Wilcoxon test
  • Where applicable, Pearson or Spearman correlations were performed between the most significant parameters as a baseline of 24 months to baseline for each group
  • All P-values were computed for a two-tailed test set for an alpha level of 0.05.
Data Collection Summary:

Timing of Measurements
Baseline and 24 months.

Dependent Variables

  • Weight: Measured in kg
  • BMI: Measured kg/m2
  • Waist circumference (cm)
  • Systolic blood pressure (mmHg)
  • Diastolic blood pressure (mmHg)
  • Fasting glucose (mM)
  • HbA1c (%)
  • Total cholesterol (mM)
  • LDL-cholesterol (mM)
  • HDL-cholesterol (mM)
  • Triglycerides (mM)
  • TC and HDL-cholesterol
  • Urinary albumin/creatinine (mg per L).

Independent Variables

  • Dietary counseling by a registered dietitian and minimal yearly endocrinologist follow-up
  • Conventional care with regular endocrinologist follow-up.

Control Variables

  • Age
  • Sex
  • Smoking status
  • Diabetes type
  • Diabetes duration
  • Diabetes medication.
Description of Actual Data Sample:
  • Initial N: 101
  • Attrition (final N): 88 subjects; DC Group, 77% female; Control Group, 66% female
  • Age: 33 years to 78 years old
  • Ethnicity: Not mentioned.

Other Relevant Demographics

  • Type 2 diabetes: DC Group, 84%; Control Group, 82%
  • Insulin therapy: DC Group, 73%; Control Group, 84%
  • 16% smokers
  • Micro- and macrovascular complications were significantly more frequent in the DC Group than in the Control Group.

Anthropometrics
The groups were similar for weight, BMI and waist circumference.

Location
University of Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.

Summary of Results:

Key Findings

  • The DC Group lost significantly more weight than the Control Group at the final 24-month follow-up. The significance continued in the adjusted P-value.
  • The BMI was significantly different (lower) in the DC Group than in the Control Group at 24 months. The significance continued in the adjusted P-value.
  • The waist circumference was significantly lower in the DC Group than in the Control Group
  • The HgA1c was significantly lower in the DC Group than in the Control Group at 24 months
  • The diastolic blood pressure was significantly lower in the DC Group at 24 months.

Variables

Treatment Group
Measures and confidence intervals

Control Group
Measures and confidence intervals

Statistical Significance of Group Difference

*Adjusted P-Value

Weight (kg)

.-0.7±4.2

2.1±4.4

P=0.004

P=0.003

BMI (kg/m2)

-0.3±1.5

0.7±1.8

P=0.009

P=0.001

WC (cm)

-1.3±1.4

2.4±7.3

P=0.009

NS
HbA1c (%) -0.6 (-1.2-0.0) -0.3 (-0.7-0.2) P=0.04 P=0.009
Dbp(mm Hg) -5.3±7.8 -1.3±10.3 P=0.049 P=0.07

* Adjusted for micro- and macrovascular differences observed at baseline between groups.

Other Findings

  • The DC Group consumed significantly more calories (35%) more than the Control Group (P=0.005) at baseline
  • The DC Group had a significantly greater net reduction of energy at 24 months: -548kcal vs. -74kcal per day; P=0.001 vs. P=0.179
  • The DC Group had a slightly significantly lower total grams of protein intake at 24 months than the Control Group
  • The DC Group had a significantly lower total grams of total fat intake at 24 months than the Control Group at 24 months
  • The DC Group had a significantly lower saturated fat intake at 24 months: -3% vs. -1%; P=0.005 vs. P=0.179
  • The monounsaturated fat intake significantly decreased in both the DC Group and the Control Group at 24 months.
Variables DC Group Control Group P-Value Adjusted P-Value
Energy (kcal/day) -548 -74 P=0.001 P=0.045
Protein g/day -14 +1 P=0.012 NS
Fat g/day -30 -5 P=0.002 NS
Saturated Fat (%) -3% -1% P=0.005 NS
Monosaturated Fat (%) -2% -4% P=0.05 NS
  • The DC Group received 50% more angiotensin-converting enzyme inhibitor at 24 months
  • The Control Group took 49% and 30% of their initial dosages of calcium-channel antagonist and diuretic drugs respectively at 24 months
  • The number of anti-hypertensive drugs was increased in the DC Group at 24 months
  • The insulin dose rose significantly by 18% in the DC Group, as compared to only 7% in the Control Group.
Variable Dietitian-Coached Group
(Baseline)
DC Group at 24 Months Control Group
(Baseline)
Control Group at 24 Months

Statistical Significance

Angiotensin-Converting Enzyme Inhibitor 50 (46-100) 75 (50-100)     P<0.05
Calcium-Channel Blocker 100 (58-100) 100 (58-100) 67 (50-100) 100 (83-100) P=0.04
Diuretic     10 (6-13) 13 (6-15) P=0.02
Insulin (U/kg/day) 0.73 (0.49-1.13) 0.86 (0.50-1.40)      
  • In the DC Group, improvement in HgA1c was positively correlated with fasting glucose
  • In the DC Group there was a positive correlation between delta 24 months to baseline DBP and waist circumference.
Variable

DC Group Correlations

DC Group Day 24 to Baseline

Statistical Significance
(P-value)

HbA1c:Fasting Glucose R=0.52   P=0.001
DBP:Waist Circumference   R=0.362 P=0.02
Author Conclusion:
  • This study compared a joint model of diabetes care management combining a motivational intervention program given by a registered dietitian and a minimal yearly endocrinologist follow up to regular endocrinologist follow-up over a 24-month period.  The study showed that the dietitian coach model was successful in modifying the HbA1c, weight, BMI, waist circumference and dietary intakes over the 24-month period. However, those improvements were not associated with any specific intervention given by the dietitian, suggesting an overall program benefit. This model offers an interesting and innovative alternative strategy to reduce diabetes-associated complications and cardiovascular diseases.
  • With respect to blood pressure and lipid control, there was no clear benefit over regular care. Improvement in nutritional habits in the DC Group did not correlate with improvement of any clinical parameters. Nutritional data were self-reported. The DC Group food logs were reviewed by the dietitian and immediately compared to the logs by the Control Group. Many participants did not complete a food log.
  • No change in physical activity was seen due to the study limitations. In this study, a questionnaire and a pedometer were used.
  • HbA1c improved independently of insulin therapy or anti-diabetic drugs
  • The joint dietitian-coached model of care provides a strategy for cardiovascular risk management in the diabetic population. More randomized clinical trials need to be conducted over several years.
Funding Source:
Industry:
Pfizer
Pharmaceutical/Dietary Supplement Company:
Reviewer Comments:
  • The author did a great job describing the study components and the study limitations
  • A wide variety of statistical methods were used to analyze the data
  • One table may show significance, however it is based on a variety of statistical test.
  • The study numbers were very small, however the author did identify when the total number used to analyze the data changed
  • A larger sample size may indicate more significant data.
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) 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? 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? ???
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? 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? 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? 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? 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? 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)? Yes
  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? Yes
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