Lifestyle Factors that Improve Metabolic Syndrome Components

Citation:

Case CC, Jones PH, Nelson K, O'Brian Smith E, Ballantyne CM. Impact of weight loss on the metabolic syndrome. Diabetes Obes Metab. 2002 Nov; 4 (6): 407-414.

 

PubMed ID: 12406040
 
Study Design:
Retrospective Cohort Study
Class:
B - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To evaluate the effect of weight loss on markers of Metabolic Syndrome (MS) in obese patients enrolled in a medically-supervised rapid weight loss program and to correlate changes in  components of MS with obesity and weight loss.

Inclusion Criteria:

·       Self-enrollment in or physician referral to rapid weight loss program in the year 2000 at Institute of Preventive Medicine

·       Enrolled patients meeting 3 of 5 NCEP criteria for MS (blood glucose >120 mg/dl; BP >130/>80 mmHg; HDL-C, M <40 mg/dl, W <50 mg/dl;  TG >150 mg/dl;  BMI > 30 was used as surrogate for waist circumference criterion (M > 102 cm, W > 88 cm).

·       Age > 18 years.

BMI > or = 30.
Exclusion Criteria:

·        Those not meeting the above criteria

AND

·          Known eating disorders

·          Cancer

·          Use of lithium or steroids

·          Type I DM

·          Active inflammatory bowel disease or active gout

·          Liver disease

·          Cardiovascular event in past 3 mos.

·          Endocrine causes of obesity

·          Pregnancy

Description of Study Protocol:

·    Diuretic medications were discontinued at start of program

·     At baseline: Evaluation by physician, ECG; consultation with RD; blood labs.

·     Follow-ups: blood labs monthly;  weekly monitoring of weight and BP and education meetings; consultation with RD as needed.

·     Protein-sparing VLCD was weight loss method used until a predetermined body weight goal (PBWG) reached: 600-800 kcals/d – 1.5 g protein/kg PBWG, used liquid beverages (Nutrimed Plus - 200 kCal, 28 g protein, 10 g CHO, 6 g fat) supplemented with lean beef, fish, or poultry.

·     Minimum 2 Liters/d fluid intake

·     When PBWG was reached, patients then went into the adapting phase of the program (8 weeks) and the sustaining phase (months) of the program.

Data Collection Summary:

·     Prevalence and characteristics of the MS was assessed in patients enrolled in 2000.by reviewing records and obesity treatment outcomes.

·     Stat analysis by SPSS (version 10.0)

·     ANOVA for repeated measures and paired t-test were used to determine differences between characteristics of those with and without the MS..

·     Independent t-test was used to investigate differences in components of the MS from baseline to 4 weeks and at the end of active weight loss.

Pearson’s correlation coefficient was used to calculate correlations of components of the MS with baseline and changes in BMI and weight.

Description of Actual Data Sample:

125/185 (68%) patients in program for at least 4 weeks met a minimum of 3/5 NCEP defining criteria for MS (46 M -37^; 79 W-63%). Average age 48.4 ± 10.4 yrs.

·     Baseline characteristics differed between those with the MS and those without the MS:

·       BMI (40.7 vs 35.7)

·       BP (140/85 vs 130/80 mmHg

·       FBG (115 vs 95 mg/dl

·       TGs (233 vs 127 mg/dl

·       HDL-C (M, 42 vs 53 mg/dl; W, 48 vs 59 mg/dl)

·       Exception: no differences were seen in TC and LDL-C between the groups.

 

 

 

Summary of Results:

·     See tables 5 below for clinically relevant and statistically significant changes in characteristics of the MS during active weight loss.

Table 5: Effect of weight loss at 4 weeks and at end of active weigth loss on the componenets of the metablic syndrome in patients with the metablic syndrome.

Variables

Initial

4 weeks

Final (average 16.7 weeks)

Weight (lbs)    

261±72.4    

244.3 ±69.5*

221.7±59.5***

BMI

40.7±9.7

38.2±9.4*

34.6±7.8***

SBP (mmHg) 139.7±12.8 128.6±11.2 *   125.1±12.8***
DBP (mmHg) 84.9±6.9 79.1±7.2* 77.0±8.0****
Glucose (mg/dl) 115.3±37.1    98±22.0* 96.3±20.6*****
TG (mg/dl)  232.7±121.3 138.6±70.8* 128.5±73.1*****

Cholesterol (mg/dl)

207.8±34.9

170.9±39.4*   

    183±38.4***

*P<0.001 compared with baseline, ** P<0.001 compared with 4 weeks, ***P=0.002 compared with 4 weeks, ****P=0.061 compared with 4 weeks, *****P=0.011 compared with 4 weeks.

Other Findings: ·     There was a trend for decreases in all characteristics of the MS with moderate (6.5%) weight loss in obese individuals during active weight loss and continued weight loss (15.1%)..

 

Author Conclusion:

The MS is prevalent in 2/3 of obese individuals enrolling in a structured weight loss program. Moderate weight loss with a VLCD markedly improved all aspects of the MS.

"Moderate weight loss at 4 weeks was an extremely effective treatment for improving all aspects of the metabolic syndrome. Weight loss was related to the change in each of the components of the metabolic syndrome. These findings support the hypothesis that excess adiposity plays a key role in the pathosiology of all facets of the metabolic syndrome. Further strategies to identify these individuals should be undertaken ,as they will benefit most from medically supervised weight loss programs."

Funding Source:
Government: NIH
Industry:
Astra Zeneca Pharmaceuticals
Pharmaceutical/Dietary Supplement Company:
Reviewer Comments:

Clinically relevant and statistically significant improvements in characteristics of the MS related to obesity were seen in response to weight loss using a multidisciplinary approach (VLCD, continued diet instruction, exercise, behavior modification) in a closely monitored setting.

Although no alternative diet control group was used for comparison, I interpret the non-MS obese subjects to be an appropriate comparison for the changes the authors were investigating

No mention of the effect on HDL-C.

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
  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
  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
  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
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
  1. Was the research question clearly stated? Yes
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
  1.1. 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? N/A
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? N/A
  1.3. Were the target population and setting specified? N/A
  1.3. Were the target population and setting specified? N/A
  2. Was the selection of study subjects/patients free from bias? 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? N/A
  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? N/A
  2.2. Were criteria applied equally to all study groups? N/A
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? N/A
  2.4. Were the subjects/patients a representative sample of the relevant population? N/A
  2.4. Were the subjects/patients a representative sample of the relevant population? N/A
  3. Were study groups comparable? 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) 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
  3.2. 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
  3.3. 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
  3.4. 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
  3.5. 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
  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. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  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
  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. 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
  5.1. 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
  5.2. 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
  5.3. 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
  5.4. 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
  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. 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? 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
  6.2. 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
  6.3. 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
  6.4. 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
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments 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
  6.7. 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
  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. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? N/A
  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. 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? N/A
  8.1. Were statistical analyses adequately described and the results reported appropriately? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  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
  8.4. 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
  8.5. 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? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
  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. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? N/A
  9.1. Is there a discussion of findings? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
  10. Is bias due to study's funding or sponsorship unlikely? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.2. Was the study free from apparent conflict of interest? N/A
  10.2. Was the study free from apparent conflict of interest? N/A