EAL

Weight Management

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To evaluate the short-term and 1-year outcomes of an intensive very-low-calorie diet on metabolic and cardiovascular variables in obese patients with Type 2 diabetes and symptomatic hyperglycemia despite combination oral anti-diabetic therapy with or without insulin, and to assess patient acceptability and the feasibility of administering VLCD treatment to this subgroup of patients in a routine practice setting.

Inclusion Criteria:

Obese patients
Poorly controlled type 2 diabetes
Symptomatic hyperglycemia despite combination oral therapy or insulin + metformin

Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Consecutive patients invited to participate.

Design

Nonrandomized Clinical Trial.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

8 weeks of VLCD therapy (750 kcal/day) with review by RD after 2, 4 and 8 weeks followed by standard diet and exercise advice at 2 - 3 month intervals up to 1 year. Insulin was discontinued at the start of the VLCD, and anti-diabetic therapy was adjusted individually throughout the study, including recommencement of insulin as required.

Statistical Analysis

Clinical and biochemical parameters at baseline, after 8 weeks of VLCD and at 1 year compared by repeated measures ANOVA.

Data Collection Summary:

Timing of Measurements

Clinical, biochemical and hemodynamic parameters recorded at baseline, 8 weeks and 1 year.

Dependent Variables

Glycemic control assessed by measurements of fructosamine
Weight
Blood samples

Independent Variables

8 weeks of VLCD therapy (750 kcal/day) with review by RD after 2, 4 and 8 weeks followed by standard diet and exercise advice at 2 - 3 month intervals up to 1 year. Insulin was discontinued at the start of the VLCD, and anti-diabetic therapy was adjusted individually throughout the study, including recommencement of insulin as required.
Home blood glucose monitoring

Control Variables

Description of Actual Data Sample:

Initial N: 44 patients agreed to participate (half of total number invited).

Attrition (final N): 40 obese patients, 22 males. 26 on combination oral therapy, 14 on insulin + metformin. 4 withdrew within first 5 days of VLCD due to distaste and poor compliance.

Age: mean age 52 years, range 33 - 69 years

Ethnicity: not mentioned

Other relevant demographics: mean BMI = 40, duration of diabetes = 6.1 years

Anthropometrics:

Location: United Kingdom

Summary of Results:

Other Findings

Immediate improvements in symptoms and early weight loss reinforced good compliance and patient satisfaction.

After 8 weeks of VLCD, body weight and BMI had fallen significantly: 119 +/- 19 to 107 +/- 18 kg (average weight loss of 12 kg) and 40.6 to 36.6, respectively, with favorable reductions in serum total cholesterol (5.9 to 4.9 mM), blood pressure (10/6 mmHg) and fructosamine (386 +/- 73 to 346 +/- 49 uM), which equates to an HbA1c reduction of approximately 1%.

Sustained improvements were evident after 1 year, with minimal weight regain, e.g. mean body weight 109 +/- 18 kg and mean BMI 37 +/- 4.

Glycemic control tended to deteriorate after 1 year - mean fructosamine was 371 +/- 41 uM and 15 patients were on insulin.

Author Conclusion:

The results indicate that 8 weeks of VLCD treatment may be effective and well tolerated in symptomatic obese patients with type 2 diabetes in secondary failure, producing sustained cardiovascular and metabolic improvements after 1 year. VLCD therapy is a treatment option that deserves greater consideration in this difficult-to-treat patient population.

Funding Source:

Government:	NHS Trust
University/Hospital:	University of Nottingham (UK)

Reviewer Comments:

Recruitment methods and inclusion/exclusion criteria not well defined. Only 50% of those invited agreed to participate. Measurement of outcomes not well described.

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?		???
	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?	???
	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?		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?	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?	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.)	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?		???
	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?	???
	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)?	N/A
	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