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PDM: Metabolic Syndrome (2013)

Citation:

Busnello FM, Bodanese LC, Pellanda LC, Santos ZE. Nutritional intervention and the impact on adherence to treatment in patients with metabolic syndrome. Arq Bras Cardiol. 2011; 97(3): 217-224.

PubMed ID: 21739068
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To evaluate two models of dietary intervention and the relationship with adherence to treatment and impact on clinical improvement of patients with metabolic syndrome.

Inclusion Criteria:
  • More than 18 years of age
  • Diagnosis of metabolic syndrome according to the criteria of NCEP-ATP III
  • Agreeing to do research before signing informed consent.
Exclusion Criteria:

None specifically mentioned.

Description of Study Protocol:

Recruitment

Local newspaper and patients linked to CVD clinic in Porto Alegre, Brazil.

Design

Randomized clinical trial.

Blinding Used

Implied with measurements.

Intervention

  • Participants were randomized assigned to the intervention or control group
  • Both groups were instructed to follow an individual standard diet for four months, using the recommendations of the First Brazilian Guideline for Diagnosis and Treatment of Metabolic Syndrome
  • Subjects in the intervention group additionally received an intervention package with Manual of Nutritional Guidelines for Patients with Metabolic Syndrome, phone call from researchers 15 days after the nutrition counseling and different printed material about nutrition guidelines at each of the four monthly visits.

Statistical Analysis

Chi-square test of Pearson for analysis of categorical variables between groups and Student's T-test to compare the means. ANOVA for comparison of biochemical parameters between groups for repeated two-way measures and for multiple comparisons, the Bonferroni test. For dietary variables, non-parametric tests were applied (Wilcoxon's tests for intra-group comparisons and Mann-Whitney tests for intergroup comparisons). To evaluate the associations between quantitative variables, Pearson's linear correlation tests or Spearman's were used. 

 

Data Collection Summary:

Timing of Measurements

Measurements made before and after the four-month intervention.

Dependent Variables

  • Anthropometrics:
    • Weight and height using Filizola scale without shoes and wearing light clothes 
    • BMI was ranked according to WHO, 1998
    • Waist circumference (WC) at midpoint between the iliac crest and inferior costal edge
    • Hip circumference (HC) at largest point of the buttocks
    • Neck circumference (NC) at midpoint of neck at the level of cricothyroid muscle.
  • Blood assessment: 
    • Triglyceride (TG)
    • Total cholesterol (TC)
    • HDL and LDL
    • Glucose
    • Uric acid and ultrasensitive C-reactive protein (usCRP).

Independent Variables

  • Participants were randomized assigned to the intervention or control group
  • Both groups were instructed to follow an individual standard diet for four months, using the recommendations of the First Brazilian Guideline for Diagnosis and Treatment of Metabolic Syndrome
  • Subjects in the intervention group additionally received an intervention package, with Manual of Nutritional Guidelines for Patients with Metabolic Syndrome, phone call from researchers 15 days after the nutrition counseling and different printed material about nutrition guidelines at each of four monthly visits
  • Dietary intake assessed by 24-hour recall.
Description of Actual Data Sample:
  • Initial N: 82 subjects (25 males, 57 females)
  • Attrition (final N): 79 subjects
  • Age: 58.5 years (SD±8.41)
  • Anthropometrics: Homogeneous in the characteristics and distribution of the components of MetS
  • Location: Brazil.
Summary of Results:

Key Findings

Variables

Treatment Group Baseline
Measures and CI
Treatment Group: Final
Statistical Significance of Group Difference

Control Group: Baseline
Measures and CI
Control Group: Final
Statistical Significance of Group Difference
Weight (kg)
82.7±12.5
81.5±12.8
0.012
81.3±14.0
79.4±14.2
<0.001
BMI (kg/m2)
32.9±3.4
32.3±3.6
0.009
32.9±3.4
30.9±3.8
<0.001
WC (cm)
109.4±8.6
107.9±9
0.017
108.1±9.8
105.9±9.5
0.001
Glucose (mg per dL)
144±61
128.2±48.2
0.061
143.7±66.2
123.5±47.1
0.012
TG (mg per dL)
189.9±81.6
169.9±76
0.023
196±85.3
163.9±70.4
0.004
TC (mg per dL)
218.5±52.1
201.9±48.8
0.011
202.3±43.4
192.3±40.9
0.037
HDL (mg per dL)
47.1±11.5
46.4±10.9
0.442
44.2±10.1
44.4±10.1
0.792
LDL (mg per dL)
133.4±47.3
123.9±49.6
0.079
119±40
115.1±34.2
0.357
Uric acid (mg per dL)
5.72±1.37
5.89±1.86
0.079
5.52±1.75
5.30±1.41
0.257
usCRP (mg per dL)
0.42 (0.21 to 0.73)
0.32 (0.17 to 0.61)
0.051
0.40 (0.16 to 0.83)
0.28 (0.12 to 0.86)
0.42

Other Findings

  • Both groups were highly motivated at the first visit. Those who were more motivated were those who had the greater reduction in BMI (P<0.001) in both groups.
  • The intervention group had a statistically significant reduction in consumption of whole milk (P=0.002) and increased consumption of whole grains (P=0.008)
  • The control group had a statistically significant reduction in the consumption of whole milk (P=0.005) and increased consumption of whole grains (P=0.027)
  • While there were no significant changes in fruit or vegetable intake in the intervention group, there was a trend towards a one-serving increase in fruit consumption in the control group (P=0.082)
  • Blood pressure and renal outcomes were not studied.
Author Conclusion:

Both groups showed significant improvement in all clinical parameters that was significantly associated with the previous motivation. Patients who arrived more motivated were those who responded better to treatment.

Funding Source:
Other: No external funding sources for the study
Reviewer Comments:

Motivation of the patients was according to the researcher's impression at the beginning of the treatment. No further information was given on how this was determined.

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? 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? 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? 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? 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)? 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? 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