DM: Effectiveness of MNT Provided by RD/RDN (2015)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To assess the efficacy of a lifestyle intervention program that can be readily translated into clinical practice for obese patients with type 2 diabetes.
Inclusion Criteria:
  • Type 2 diabetes (ICD-9 codes, 9th revision) 250.XXX, 357.2, 362.0, or 366.41 and confirmed by physician
  • Use of diabetes medications
  • BMI greater than or equal to 27kg per m2
  • Age greater than or equal to 20 years
  • Ability to comprehend English
  • Membership in the Southern Health Services (SHS) health plan.
Exclusion Criteria:
  • Pregnancy
  • Cognitive limitations
  • Medical reasons precluding dietary and physical activity modifications.
Description of Study Protocol:


  • Identification of eligible participants from SHS data
  • Mailed invitations with participant-initiated contact
  • Phone and in-person screening by study personnel.


Eligible participants were randomly assigned to case management or to usual care, using randomly permuted blocks with randomly chosen block sizes of two to four, provided by the biostatistician. Intervention included:

  • Indiviual sessions occured six times throughout the year, totaling four hours
  • Participants attended six one-hour small group sessions
  • Brief monthly phone contacts provided support.

Blinding Used

Not applicable.


  • One RD case manager met with participants individually, in groups and by phone for assessment, goal seetting, education and support
  • Goals were based on national dietary recommendations for people with type 2 diabetes and obesity and were tailored
  • RD measured weight and waist circumference, followed lab results and discussed patient care issues with physicians when appropraite.

Statistical Analysis

  • Group differences were analyzed using intention to treat methods
  • Repeated-measures models (described more fully in article) compared groups regarding changes in weight, waist circumference, HbA1c and use of medications
  • F tests were used to make overall comparisons
  • Contrasts were used to make comparisons between groups at specific follow-up times
  • Regression models were used to compare 12-month HRQOL (Medical Outcomes Short Study Form for Quality of Life) between groups.
Data Collection Summary:

Timing of Measurements

  • Body weight, height and waist circumference were measured at baseline and at four, six, eight and 12 months
  • HbA1c was measured at baseline and at four, eight and 12 months
  • Fasting lipid levels at baseline and at 12 months
  • Medications were transcribed (name of medication, dose prescribed and quantity taken daily) from participant prescription containers by study personnel at baseline, six and 12 months.

Dependent Variables

  • Weight
  • Waist circumference
  • Glycemic control
  • Lipid levels
  • Use of prescripion medications
  • HRQOL (Medical Outcomes Short Study Form [SF-36]).

Independent Variables

  • Case management (as described above)
  • Usual treatment protocols.

Control Variables

Not specified.

Description of Actual Data Sample:
  • Initial N: 147 were randomized
  • Attrition (final N): 118
  • Age: 53.4±8.0 (usual care); 53.3±8.6 (case management)
  • Ethnicity: 74% of usual care group and 85% of case management group were Caucasian. Other ethnicity not specified.
  • Other relevant demographics: 58% of usual care group and 62% of case managment group were women. Groups were similar in demographics at baseline and include smoking, marital status, medications and items from the SF-36.
  • Anthropometrics: Groups were similar in clinical measures at baseline and include weight, BMI, waist circumference, HbA1c and cholesterol (total, LDL, HDL, triglycerides) 
  • Location: Within a 30-mile radius of the site at the University of Virginia Clinical Research Center.


Summary of Results:

Of the 147 randomized into usual care and case management group, three dropped out before baseline measures; 29 withdrew (10 from usual care, 19 from case management).

Of the remaining case managment participants, 100% attended all individual sessions and 78% attended four or more group classes. The number of classes attended was not associated with outcomes.


  • Mean weight change differed significantly (P<0.001). The greatest difference was at eight months with the case management group (-4.0kg, 95% CI -5.6 to 12.5) and net weight loss between groups (-5.0kg, -7.2 to 2.9).
  • At 12 months, case management group participants lost an average of -2.4kg (-4.1 to 0.6), compared to usual care participants who gained an average of 0.6kg (-1.0 to 2.2), a net difference of -3.0kg (-5.4 to -0.6)
  • More participants in the case management group lost up to 5% (53 vs. 32%) and greater than or equal to 5% (20 vs. 14%) of initial weight.

Waist circumference:

  • At 12 months, participants in the case management group lost -5.5cm (-7.4 to 3.6), whereas the usual care group lost 1.4cm (-3.1 to 0.4).


Differed over the intervention period (P=0.02). Change in weight did not predict change in HbA1c. Post-hoc subanalyses indicated differential effects of treatment by initial glycemic control.

  • Difference was greatest at four months: -0.57%, -1.0 to -0.2; P=0.008
  • At eight months: -0.35%, -0.8 to 0.1
  • At 12 months: 0.20%, -0.7 to 0.3; P=0.45

Lipid levels:

The 12-month between-groups differences were not statistically different, for total cholesterol, LDL, HDL or triglycerides.

Prescription medications:

  • At 12 months, the case managment group participants were taking 0.8 (0.05-1.1) fewer total medications per day than the usual care group (P=0.03)
  • At six months, more individuals in the case management group decreased total medications, compared with the usual care  (45% vs. 28%) and fewer individuals in the case management group increased medications, compared with the usual care (19% vs. 35%)
  • Although the magnitude of the differences remained similar (decrease: 57% vs. 39%; increase: 17% vs. 32%), these differences were no longer significant by 12 months. (P=0.13)
  • There was a decrease in unique medications, primarily due to a decrease in diabetes medication (P=0.003). By 12 months, the case management group reduced diabetes medications 0.46 medications per day more than those in the usual care group (P=0.001). Insulin and sulfonylurea decreased most among participants in case management, while thiazolidinedione increased slightly among usual care.

Quality of life:

  • Baseline SF-36 scores were lower than national norms, but consistent with scores reported among obese individuals
  • Change in SF-36 scores was significantly different in the case management group from the usual care group in seven of nine domains
  • The domains with the greatest improvements were emotional role (15.1, 3.4-26.8) and physical role (10, 1.2-24.7).
Author Conclusion:
  • ICAN results suggest that a modest-cost, easily translated RD case management approach to lifestyle care can improve diverse indicators of health, including weight, waist circumference, HRQOL and use of prescription medications among obese persons with type 2 diabetes
  • Although the magnitude of weight loss may not meet patients' and physicians' expectations, the benefits from the patient, clinical and payer perspective outweigh the relatively low cost of such a program
  • This study also pointed out that those who did not receive lifestyle care, but remained medically managed, gained weight, had reduced quality of life and sustained their need for medication
  • During ICAN, maximal weight loss occured in the period of more frequent contact with RD case managers. Although a decrease in intensity and support was intentional in Months Eight to 12 as a way to transition participants from intervention to maintenance, weight regain in the last four months suggests a need for ongoing lifestyle coaching
  • The impact on laboratory parameters was modest and not significant by one year. The small changes may reflect the already good medical management. By design, all participants had health insurance and were taking diabetes medications. Participants had generally good control of HbA1c and lipid levels.
Funding Source:
Government: NIDDK
University/Hospital: University of Virginia GCRC
Foundation associated with industry:
Reviewer Comments:
  • Extensive discussion of results of the different measures
  • Includes graphs of each outcome measure for both groups at baseline, four, eight and 12 months.
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? 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? 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? ???
  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? No
  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? N/A
  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)? ???
  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? 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