Risk of Developing Metabolic Syndrome

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To evaluate the effect of leisure time physical activity (PA) and the Mediterranean diet on Metabolic Syndrome (MS) as defined by ATP III guidelines.
Inclusion Criteria:
All residents of the province of Attica, Greece, 18 or older. Only one person per household was enrolled.
Exclusion Criteria:

Excluded:
402- clinical evidence of CHD, stroke, diabetes, any atherosclerotic disease

Description of Study Protocol:

Recruitment : Health and nutrition survey of residents of Attica, Greece. One person per household was enrolled from 2001-2002.  Sample was chosen to represent the demographics of the country, based on the 2000 census.  3,335 were slected for participation, 2,684 agreed to participate.

 

Design : Cross sectional

 

Blinding used (if applicable) n/a

 

Intervention (if applicable) n/a

 

Statistical Analysis: Student's T test for comparison of those with MS and those without.  Mulitple logistic regression to determine the odds of MS as a function of PA and Mediterranean Diet, while controlling for several lifestyle and demographic factors.

 

Data Collection Summary:
Timing of Measurements: All measurements taken at the same time.

 

Dependent Variables

MS as defined by ATP III

Table III. National Cholesterol Education Program/ ATP III criteria for Metabolic Syndrome

Risk Factor

Defining Level

Abdominal obesity:

            Men

            Women

Waist circumference

            >102 cm (>40 in)

            > 88 cm (>35 in)

Hypertriglyceridemia

>150 mg/dL (1.69 mmol/L)

Low HDL cholesterol

            Men

            Women

 

<40 mg/dL (1.04 mmol/L)

<50 mg/dL (1.29 mmol/L)

Elevated blood pressure

 >130/85 mm Hg

High fasting glucose

>110 mg/dL (>6.1 mmol/L)

* MS is defined as individuals meeting 3 or more of the listed criteria.

 

Indepedent Variables:

Mediterranean Diet: Individuals who were "close" to the median value of monthly averge of food items consumed according to the dietary pattern "suggested" by a Harvard-led group. Pattern=daily consumption of whole grains, 2-3 servings/day of vegetables, olive oil as the main added fat, dairy 1-2 servings/day, fish 2 X/wk, poultry 3-4 X/wk, olives/pulses (beans)/nuts 3X/wk, potatoes/eggs/sweets 3-4 X/wk, red meat 3X/month, 1-2 glasses wine/day, and a mono: sat fat ratio of 2.

Physical Activity: any type of non-occupationsal physical activity at least 1X/wk over the last year. This was also graded qualitatively based on type of activity. Those without activity at least 1X/ wk were labeled as inactive.

Control variables: smoking/CRP/Apolipoprotein A and B/ age/gender/WBC count/ lipoprotein a/ homocysteine/ fibrinogen/ amyloid A 

 

Description of Actual Data Sample:

Initial N: total 3,355 enrolled, 2,684 agreed to participate, 402 excluded

Attrition (final N): total 2,282,          1,128 men                     1,154 women

Age: Subjects with MS:      male   51 +/- 12 years    female 55 +/- 13 years

        Subjects without MS: male 45 +/-13 years        females 44 +/- 11 years

         Info not given for entire population

Ethnicity: Causacian residents of Greece

Other relevant demographics: n/a

Anthropometrics (e.g., were groups same or different on important measures)

Location: Attica, Greece

 

Summary of Results:

 

Variables

 Follow Med Diet Group

OR and confidence intervals

  Do not Follow Med Diet group

Measures and confidence intervals

Statistical Significance of Group Difference

MS (while controlling for a series of covaribles)

0.810 (0.680-0.976)

 

 

 

Stat signif difference between groups

p=.014

 

 

 

 

 

 

 

 

 

Variables

Physically activ

Measures and confidence intervals

Not Physically Active group

Measures and confidence intervals

Statistical Significance of Group Difference

MS (while controlling for a series of covariables)

0.570 (0.325-0.832) (high PA)

 

 NO p VALUE!

 

0.75 (0.65-0.86) (Light-Mod PA)

 

 NO p VALUE !

 

 

                                        

P value for physical activity status 0.47 but NO p VALUE specific categories of PA (high or light-mod).

OR were after adjusting for "several lifestyle, demographic, inflammation and coagulation factors". Specific variables were not listed.

Other Findings:
There was a significant difference (T test) between those with MS and without who did and did not consume the Med. diet (p=0.030).

There was NO significant difference (T test) between those with MS and those without who did and did not meet the PA criteria.

Apolipo A1, B, CRP, LDL, WBC, Homocysteine, Fibrinogen were all significantly different between those with MS and those without (T test p<0.05)

 

Author Conclusion:
"our findings emphasize the importance of the consumption of a dietary pattern "close" to the Mediterranean Diet and the adoption of even light- to moderate physical activity to reduce the prevalence of MS at the population level"
Funding Source:
University/Hospital: University of Athens
Not-for-profit
0
Foundation associated with industry:
Reviewer Comments:

The results were very confusing. For demographics they had already seperated the population based on the outcome.  They then preformed a series of T tests to determine if there were any significant differences between the two groups for any demographics or metabolic markers. This

It seems they made Med. diet variables dicotomous instead of using it as continuous variables, which is more intuititve (as compliance with the diet increases risk of MS decreases,etc.). The PA score appears to be categorical, yet it was described in the methods as dicotomous.

There is a considerable amount of time spent talking about the covariables and MS, without including the Med. Diet and PA variables.  Many of the presented results did not answer the research question.

The decrease in risk reduction for the population was not significant.

Overall this was a poorly analyzed and poorly presented study.

 

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) N/A
  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) N/A
  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) N/A
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
 
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? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
  1.3. Were the target population and setting specified? Yes
  2. Was the selection of study subjects/patients free from bias? N/A
2. Was the selection of study subjects/patients free from bias? 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
  2.1. 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? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? ???
  2.3. Were health, demographics, and other characteristics of subjects described? ???
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
  3. Were study groups comparable? N/A
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) 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
  3.2. 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.) ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) ???
  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? ???
  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? ???
  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? N/A
4. Was method of handling withdrawals described? N/A
  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? N/A
5. Was blinding used to prevent introduction of bias? N/A
  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? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? N/A
  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? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? N/A
  7.1. Were primary and secondary endpoints described and relevant to the question? No
  7.1. Were primary and secondary endpoints described and relevant to the question? No
  7.2. Were nutrition measures appropriate to question and outcomes of concern? 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? 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? 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
  7.5. 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
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? 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? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? N/A
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? No
  8.2. Were correct statistical tests used and assumptions of test not violated? No
  8.2. Were correct statistical tests used and assumptions of test not violated? No
  8.3. Were statistics reported with levels of significance and/or confidence intervals? 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
  8.4. 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
  8.5. 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? No
  8.6. Was clinical significance as well as statistical significance reported? No
  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? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? N/A
  9.1. Is there a discussion of findings? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? ???
  9.2. Are biases and study limitations identified and discussed? ???
  10. Is bias due to study's funding or sponsorship unlikely? N/A
10. Is bias due to study's funding or sponsorship unlikely? N/A
  10.1. Were sources of funding and investigators' affiliations described? No
  10.1. Were sources of funding and investigators' affiliations described? No
  10.2. Was the study free from apparent conflict of interest? No
  10.2. Was the study free from apparent conflict of interest? No