Transcript Effectiveness of Mediterranean Diet vs. DASH Diet in

Effectiveness of Mediterranean
Diet vs. DASH Diet in Reducing
Cardiovascular Risk Factors
Hannah Lapkin
GNUR 450
Background
• More than 2, 200 Americans die daily from CVD
– One death every 39 seconds
– Cause of 1/6 deaths in U.S. in 2007
• Major risk factors:
– Hypertension (>120/80 mmHg): 33.5%
– High Cholesterol (>240 mg/dl): 15%
– Obesity (BMI > 30 kg/m2): 33.7%
• Financial Implications
– Estimated cost of CVD: $268 billion
– Cardiovascular operations/procedures increased
27% from 1997
PICOT Question
• In patients with the cardiovascular disease risk factors
of hypertension and elevated cholesterol, how does
the Mediterranean diet compare with the DASH diet in
effectively reducing blood pressure and serum
cholesterol levels over six months with bi-monthly
counseling with an RD?
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P: High-risk CVD patients
I: Mediterranean diet
C: DASH diet
O: Reduced blood pressure and cholesterol
T: 6 months
• Significance
Literature Review
• DASH Diet
– High consumption of fruits, vegetables, whole grains, nuts/legumes,
low-fat dairy products
– Low consumption of sodium, red/processed meats, saturated/total fat
– Used in U.S. for prehypertensive/hypertensive individuals
• Studies show significant reductions in total/LDL cholesterol and estimated
CHD risk
• Mediterranean Diet
– Composed of:
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Abundance of plant foods
Minimal red and processed foods
Moderate amount of dairy products
Olive oil as main lipid source
Low-moderate consumption of wine with meals
– Evidence demonstrates:
• Lower serum triglycerides, cholesterol, and systolic/diastolic blood
pressure
Table of Relevant Studies
Study
Results
Gaps
Kastroini, Milionis, Esposito,
Guigliano, Goudevenos, &
Panagiotakos. 2011
-Adherence to Med. Diet reduced waist
circumference, triglycerides, hypertension,
glucose, and increased HDL
-No specified details of Med. Diet
-Inability to control for confounders
Levitan, Wolk, & Mittleman.
2009.
-Greater consistency with DASH
associated with lower heart failure events
and reduced blood pressure and LDL/HDL
cholesterol
-Only looked at men ages 45-79
-DASH diet component score was not
validated
Serra-Majem, Roman, & Estruch.
2006
-Med. Diet associated with improved
lipoprotein levels, metabolic syndrome,
and myocardial and CVD mortality in
obese patients with previous MI
-Identified that no previous RCT had
determined the extent to which the Med. diet
is more effective than typically low-fat CVD
diet (DASH)
Sofi, Abbate, Gensini, & Casini.
2010
-Adherence to Med. diet has significant
protective factors on overall mortality and
cardiovascular incidence and mortality
-Studies of short duration
-Limited ability to transfer adherence score to
the general population
Swain, McCarron, Hamilton,
Sacks, & Appel. 2008.
-All diets improved cardiovascular risk
factors but the blood pressure, cholesterol,
and overall risk was lowered the most in
higher protein diets.
-Only a 19-week study
-Didn’t investigate adherence of each diet in
free-living individuals
Tyrovolas & Panagiotakos. 2010
-Fish consumption lowers CVD risk with
decreased HTN, high cholesterol, and allcause mortality.
-Daily fruit/vegetable consumption reduces
risk of MI
-Identified that studies need to determine the
feasibility of the integration of the
Mediterranean diet into other countries and
cultures.
Search Strategy
• Databases
– EbscoHost
– Ovid
– Pub Med
• Search Terms
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Cardiovascular disease
Heart disease
DASH diet
Mediterranean
Cholesterol
Hypertension
• Study inclusion
Criteria
– English-language
– Years 2007-2012
Design
• Pretest-Posttest
experimental design
• Randomized into two diet
arms
– Each of 50 individuals
– Stratified equally into
men and women
• 6 months
• Bi-monthly counseling
with a trained RD
• Evaluation
– BP readings at baseline,
monthly, and at end
– Serum cholesterol values
assessed at baseline, 3month mark, and end
– Food frequency
questionnaires bi-monthly
• Adherence test
DASH Diet
Mediterranean Diet
Energy Level
2100 kcal
2100 kcal
Total Fat
27%
37%
Saturated Fat
6%
6%
Carbohydrates
55%
45%
Protein
18%
18%
Cholesterol
150 mg
150 mg
Fiber
30 g
30 g
Recommendations
6-8x whole grains, 4-5x fruit, 45x vegetables, 2-3x low-fat/fatfree dairy, 2-3x fats/oils,
sweets/added sugar (5x weekly),
nuts/seeds/legumes 4-5x weekly)
1-2x fruit, 2+ vegetables, 1-2x
olive oil, bread, pasta, rice,
couscous (preferably whole
grain) at every meal; 2x low-fat
dairy with herbs and spices
(instead of salt) daily; 2x white
meat, 2+ seafood, 2-4x eggs, 2+
legumes, 3+ potatoes, less than
2x red/processed meats, less
than 2x sweets weekly, wine in
moderation
Sample
• Method
– Research nurses will recommend study to patients at a cardiac unit that
meet inclusion/exclusion criteria
– Stratified random sampling by gender
• Size
– 50 men/50 women
– 50/each diet arm
• Inclusion/Exclusion
Inclusion
Criteria
Exclusion
Criteria
Blood
pressure
>120/80 mmHg
>160/100 mmHg
Cholesterol
>220 mg/dL
>280mmHg
Diet
Must accept and
enjoy diet plans
from BOTH arms
Food allergies
Age
> 35 years
< 35 years
Medication
NOT on blood
pressure or
cholesterol
medication
ON blood pressure
or cholesterol
medications
Methods for Data Collection
• Blood pressure readings
– Baseline
– Monthly
• Serum cholesterol blood draws
– Baseline
– Month 3
– End of Month 6
• 2008 NHANES Food Frequency Questionnaires
– 110-food item list
– Bi-monthly with counseling sessions
– Ensure adherence
• Food Diaries
– To review with RD and ensure accurate FFQ responses
Intervention Protocol
• Two RDs working in a cardiology unit will deliver
intervention through bi-monthly counseling
– Assigned to either DASH/Mediterranean Diet arm
– Must be similar in personality
• Will take personality test to ensure similarity
• Training program to ensure fidelity
– Trained on specifics of each diet, nutrient composition and
energy requirements, optimal methods to implement the goals
– Ensure RDs are equally knowledgeable on their assigned diet
arm and can adequately counsel participants.
Procedures for Data Collection
• Bi-monthly counseling sessions
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Review and analyze food diaries
Offer suggestions on improving adherence to assigned diet
Provide assistance on following assigned diet
RD will chart on each counseling session using de-identified data
(identification numbers for participants)
• Food Frequency Questionnaires completed by
participants at time of counseling session
• Trained laboratory technician will:
– Take blood pressure readings monthly
– Do blood draws at baseline, 3-month mark, end to assess cholesterol
values
• Research analysts will assess
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RD chart notes
Food Frequency Questionnaires
Blood pressure readings
Serum cholesterol values
Measures for Data Collection
• Blood pressure readings and blood tests
– Reliability: extremely reliable
• Laboratory technicians will also be highly-trained to enhance reliability
– Validity: extremely valid
• Highly-trained lab technicians also enhances validity
• Food Frequency Questionnaires
– Reliability: Moderately reliable
• Hindered due to self-reporting; may report what they think researchers
want to see
– Validity: Deemed valid sources of adherence in a number of
nutritional experiments
Proposed Data Analysis Plan
• Independent t-test
– Comparing different diet arms
in two groups
• Repeated measures analysis
of variance (ANOVA)
– Study participants will be
assessed at 3 different points
of time
Human Subjects Issues
• Approved by Loyola IRB
• Informed of study through research nurse
• De-identified data to minimize potential biases
– Identification numbers received at time of consent
• Participants will consent to participation through signed waiver
– Informed consent waiver
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Statement of participant status
Study goals
Type of data collected and procedures used
Nature of commitment
Sponsorship of study
Method of participant selection
Potential risks and benefits
Alternative treatments
• No diet therapy was unethical
Study Challenges
• Financially difficult
– Bi-monthly counseling for 100 participants
• Time commitments
– Bi-monthly counseling appointments
– Food logging
• Small sample size
– Maybe too small for statistical power
• Potential limited diversity
– Consequently limiting generalizability
• Selection bias due to convenience sampling
– Threat to validity
• Self-reporting inaccuracies of food frequency
questionnaires
– Only provide broad, general view of adherence
References
Fundacion Dieta Mediterranea. (2011). The FDM presents the new Mediterranean diet pyramid. Retrieved from http://fdmed.org/en/the-fdmpresents-the-new-mediterranean-diet-pyramid/
Kastroini, C., Milionis, H., Esposito, K., Guigliano, D., Goudevenos, J., & Panagiotakos, D. (2011). The effect of Mediterranean diet on metabolic
syndrome and its components: A meta-analysis of 50 studies and 534,906 individuals. Journal of the American College of Cardiology, 57(11),
1299-1313.
Levitan, E., Wolk, A., & Mittleman, M. (2009). Relation of consistency with the dietary approaches to stop hypertension diet and incidence of heart
failure in men aged 45 to 79 years. American Journal of Cardiology, 104, pp. 1416-1420.
Roger, V., Go, A., Lloyd-Jones, D., Adams, R., Berry, J., Brown, T., Carnethon, M., Dai, S., de Simone, G., Ford, E., Fox, C., Fullerton, H.,
Gillespie, C., Greenlund, K., Hailpern, S., Heit, J., Ho, P., Howard, V., Kissela, B., Kittner, S., Lacklund, D., Lichtman, J., Lisabeth, L., Makuc,
D., Marcus, G., Marelli, A., Matchar, D., McDermott, M., Meigs, J., Moy, C., Mozaffarian, D., Mussolino, M., Nichol, G., Paynter, N.,
Rosamond, W., Sorlie, P., Stafford, R., Turan, T., Turner, M., Wong, N., & Wylie-Rosett, J. (2010). Heart disease and stroke statistics—2011
update: A report from the american heart association. Circulation, 123, pp. e18-e209.
San Vincente, R., Perez, I., Ibarra, J., Berranondo, I., Uribe, F., Urraca, J., Samper, R., Aizpurua, I., Almagro, F., Andres, J., & Ugarte, R. (2008).
Clinical practice guideline on the management of lipids as a cardiovascular risk factor. Retrieved from
http://www.guideline.gov/content.aspx?id=15711&search=basque+mediterranean+diet
Serra-Majem, L., Roman, B., Estruch, R. (2006). Scientific evidence of interventions using the Mediterranean diet: A systematic review. Nutrition
Reviews, 64 (2), p. S27-S47.
Sofi, F., Abbate, R., Gensini, G., & Casini, A. (2010). Accruing evidence on benefits of adherence to the Mediterranean diet on health: An updated
systematic review and meta-analysis. American Journal of Clinical Nutrition, 92, pp. 1189-1196.
Swain, J., McCarron, P., Hamilton, E., Sacks, F., Appel, L. (2008). Characteristics of the diet patterns tested in the optimal macronutrient intake trial
to prevent heart disease (omniheart): Options for a heart-health diet. Journal of the American Dietetic Association, 108, pp. 257-265.
Tyrovolas, S. & Panagiotakos, D. (2010). The role of Mediterranean type of diet on the development of cancer and cardiovascular disease in the
elderly: A systematic review. Maturitas, 65, pp. 122-130.
U.S. Department of Health and Human Services (2006). Your guide to lowering your blood pressure with DASH: Dash eating plan. NIH Publication
No. 06-4082.