Mediterranean Diet and the Prevention and Treatment of CVD
Toobert DJ, Glasgow RE, Strycker LA, Barrera M Jr., Radcliffe JL, Wander RC, Bagdade JD. Biologic and quality-of-life outcomes from the Mediterranean Lifestyle Program: a randomized clinical trial. Diabetes Care, 2003 Aug; 26 (8): 2,288-2,293.PubMed ID: 12882850
To study the effectiveness of the Mediterranean Lifestyle Program, a comprehensive lifestyle self-management program (Mediterranean low-saturated-fat diet, stress management training, exercise, group support and smoking cessation), in reducing cardiovascular risk factors in post-menopausal women with type 2 diabetes.
- Diagnosis of type 2 diabetes for at least six months
- Living independently
- Having a telephone
- Able to speak English
- Not developmentally disabled
- Living within 30 miles of Eugene, Oregon.
- Being under 75 years of age
- Planning to move from the area within the study's time span.
Letter was sent to eligible participants from their primary care providers, followed by a follow-up phone call inviting them to participate.
- Participants were randomized to either a usual care or treatment (MLP) condition
- MLP participants took part in an initial three-day retreat, followed by six months of weekly meetings to learn and practice program componenets.
- Mediterrean Lifestyle Program (MLP), which addressed diet, physical activity, stress management, social support and smoking
- The program context, materials, logo, music, intervention space and key components (including diet) were designed to produce a "Mediterranean feel"
- To build a sense of community, a social support intervention delivered by professional and lay leaders was included.
Timing of Measurements
- Six months.
- HbA1C: Ion-exchange high-performance liquid chromatography, using the BioRad Variant II Instrument
- Plasma fatty acids: Extracted twice with five ml chloroform/methanol and transesterified with boron trifluoride and methanol
- BMI: Converted from morning digital scale
- Waist-to-hip circumference: Hip girth was measured at the maximum circumference of the buttocks. To compute waist-to-hip ratio, waist was measured in centimeters was divided by hips measured in centimeters
- Blood pressure: A random-zero sphygmomanometer, using the Heritage protocol
- Flexibility: Trunk flexion and shoulder range of motion
- Quality of life: Medical Outcomes Study (MOS) Short-Form General Health survey.
MLP (Meditarranean Lifestyle Program).
- Initial N: 279
- Attrition (final N): 245 (12% attrition rate)
- Age: Post-menopausal women 75 years of age or younger
- Ethnicity: Not stated
- Other relevant demographics: Living within 30 miles of Eugene, Oregon
- Anthropometrics: No differences between groups on these measurements
- Location: Eugene, Oregon.
Statistical Significance of Group Difference
7.43 ± 1.3
|6 months||7.07 ± 1.11||7.38 ± 1.33|
|202.38 ± 149.06||171.59 ±110.56||
176.82 ± 113.98
157.93 ± 88.2
|6 months||187.61 ±35.60||180.72 ±39.73|
|35.34 ±7.93||34.87 ±8.20||
34.97 ± 7.85
- Six-month differences on serum lipids between UC and MLP did not acheive statistical significance, but favored the MLP condition
- MANCOVA across all quality-of-life dimensions revealed overall improvements in favor of the MLP participants
- MLP participants' blood pressure and flexibility improved and UC participants' conditions slightly worsened
- MANCOVA for the plasma fatty acid profile neared statistical significance (P=0.059).
- The authors did demonstrate that the MLP produced consistent and significant greater improvements than the UC in all the five targeted behavioral risk factors: Eating patterns, physical activity, social support, stress management and coping, smoking cessation.
- The authors did state their limitations in ethnic diversity, even though their sample was heterogenous in socio-economics, income, education and 96% covered by medical insurance
- The authors also stated that they reduced the intensity of their MLP from their initial study because of the inverse relation between program intensity and reach.
- This research article was very organized in its written delivery, stated clinical improvements and limitations and also stated other research questions to pursue
- The authors were very honest about the concerns with intensity of an MLP and participation interest also.
Quality Criteria Checklist: Primary Research
|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|
|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?||???|
|2.4.||Were the subjects/patients a representative sample of the relevant population?||???|
|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.)||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?||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?||No|
|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.)||No|
|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?||???|
|6.6.||Were extra or unplanned treatments described?||???|
|6.7.||Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?||???|
|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?||???|
|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)?||Yes|
|8.5.||Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?||???|
|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|
|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|