Evangelou P, Tzotzas T, Christou G, Elisaf MS, Kiortsis DN. Does the presence of metabolic syndrome influence weight loss in obese and overweight women? Metab Syndr Relat Disord. 2010; 8(2): 173-178.
PubMed ID: 20156072![Neutral](/lib/img/icon/icomoon/gradient/contrast.png)
To examine whether the presence of metabolic syndrome and its components influence weight loss in obese and overweight women during a short-term, dietary-based intervention program.
- BMI higher than 25kg/m2
- Female.
- Male gender
- Symptomatic ischemic heart disease or any other clinically evident vascular disease
- Abnormal liver function, impaired renal function, T2DM, thyroid or other endocrine disorders
- Women on HRT.
Recruitment
Consecutive patients attending the Outpatient Obesity and Lipid Clinic.
Design
Non-randomized trial. Assignment to metabolic syndrome or no metabolic syndrome group.
Blinding Used
Implied with measurements.
Intervention
Individualized low-fat diet of an average calorie restriction of 1,000kcal per day. The prescribed diet mean was 1,485±412kcal per day ranging from 1,085 to 2,000kcal per day. The average macronutrient distribution was 52.5%±4.1% CHO, 28.5%±3.2% fat and 19.0%±1.4% protein. Patients were asked to attend the clinic monthly to assess dietary compliance. Orlistat or sibutramine were added if necessary.
Statistical Analysis
Smirnov test, and logarithmic transformation were accordingly performed. The paired-sample T-test was used for assessing the effect of treatment in each group. Independent-sample T-test and ANOVA, adjusted for comparisons, were assessed the the chi-squared test. Every change was examined after adjustment for any random factors that could bias the result. Correlations were tested using the Spearman P-test.
Timing of Measurements
Baseline and three months after an overnight fast.
Dependent Variables
- TC, HDL-C and TG determined enzymatically
- LDL-C calculated using Friedewald formula
- Non-HDL-C calculated as TC-HDL-C
- HOMA-index: Fasting insulin, fasting glucose (405).
Independent Variables
- Metabolic syndrome vs. no metabolic syndrome
- Individualized low-fat diet of an average calorie restriction of 1,000kcal per day. The prescribed diet mean was 1,485±412kcal per day ranging from 1,085 to 2,000kcal per day. The average macronutrient distribution was 52.5%±4.1% CHO, 28.5%±3.2% fat and 19.0%±1.4% protein. Patients were asked to attend the clinic monthly to assess dietary compliance. Orlistat or sibutramine were added if necessary.
- Diet intake by a four-day food record.
- Initial N: 107 females enrolled
- Attrition (final N): Not described, assumed 107 females
- Age: 49.1±13.5 years
- Other relevant demographics: 63 with metabolic syndrome and 44 without
- Anthropometrics: Total calories and micronutrient composition of the diet did not differ at baseline. Metabolic syndrome group was older (P<0.05) and had higher systolic and diastolic blood pressure (P<0.05), higher TG levels (P<0.01) and lower HDL-C (P<0.01) than those without metabolic syndrome.
- Location: Greece.
Key Findings
Variables |
No Metabolic Syndrome Group % Change |
Metabolic Syndrome Group % Change |
Statistical Significance of Group Difference |
Weight |
–4.5±3.0 |
–6.62 ± 4.0 |
P<0.05 |
Waist Circumference |
–1.4±5.0 |
–5.4 ± 5.6 | P<0.053 |
BMI |
–4.5±2.8 |
–6.4 ± 4.0 |
P <0.05 |
Systolic BP |
–1.8±12.2 |
–8.3±9.2 |
P<0.05 |
Diastolic BP |
–0.3±11.6 |
–6.5±9.1 |
P<0.05 |
Plasma glucose |
–2.5±9.0 |
–3.5±8.4 |
NS |
HDL |
–5.2±13.9 |
–7.4±14.1 |
NS |
TG |
–1.9±37.1 |
–18.1±30.7 |
P<0.05 |
Other Findings
- A positive correlation between the patients' age and the components of the metabolic syndrome were present at baseline (Spearman P=0.223; P<0.05)
- Both groups lost weight : No metabolic syndrome from 93.2kg to 89kg (P<0.001) and in metabolic syndrome from 91.9kg to 85.7kg (P<0.001). The weight loss, corrected for the weight-reducing intervention including drugs and the patient's age, was greater in the metabolic syndrome group compared to the no metabolic syndrome. A correlation was found between the mean weight loss and the number of the components of the metabolic syndrome present in each patient at baseline (Spearman P=0.329; P<0.01).
- The mean weight loss was independent from the BMI at baseline in both groups
- When the subjects were divided into quartiles according to their initial HOMA-index, the patients of the quartile with the higher mean HOMA-index lost significantly more weight than the rest (8.17%±3.34% vs. 5.59%±3.87%; P<0.05).
Obese and overweight patients with metabolic syndrome showed a greater reduction of their body weight, compared to the patients without metabolic syndrome. The components of the metabolic syndrome present at baseline correlated positively with the percentage of the weight loss. The patients with the highest levels of HOMA-IR at baseline lost significantly more weight than those with lower levels of this parameter.
University/Hospital: | University of Ioannina, Greece; Panagia General Hospital, Greece |
Methodology for measuring waist circumference and blood pressure was not described. Attrition was not described nor was the number of patients who attended the monthly clinic for compliance assessment.
Quality Criteria Checklist: Primary Research
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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? | 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? | ??? | |
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? | No | |
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? | ??? | |
4.1. | Were follow-up methods described and the same for all groups? | ??? | |
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%.) | ??? | |
4.3. | Were all enrolled subjects/patients (in the original sample) accounted for? | ??? | |
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? | 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? | 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 | |