Magnetic Resonance Imaging-Portfolio Diet Study #7 (MRIPD#7)
Presently in Canada, 29% of deaths are due to cardiovascular disease (CVD), costing $20.9 billion annually. The investigators have, therefore, brought together an unique network of investigators at different stages in their careers with a range of disciplines (nutrition, cardiology, diabetes, imaging, physics, clinical trials, statistics, laboratory medicine, primary care, genetics, psychology, knowledge translation (KT), and epidemiology) and with international recognition , experience and connections, to undertake a multi-centre study which will test the ability of the dietary Portfolio PLUS approach over 3 years to reduce the progression of plaque build-up in the carotid artery as assessed by Magnetic Resonance Imaging (MRI) in individuals with hypercholesterolemia.
The dietary portfolio of cholesterol-lowering foods (viscous fibres, soy protein, plant sterol and nuts) which has been proven in many of their studies to be an effective cholesterol-lowering diet will be further enhanced by increased levels of monounsaturated fats (MUFA) and low glycemic index foods. Will this enhanced dietary strategy (dietary Portfolio PLUS ) reduce the progression of carotid atheromatous lesions, LDL-C and blood pressure while reducing the number of hyperlipidemic individuals requiring statins?
Behavioral: Portfolio Plus Diet
Behavioral: DASH-like (high fibre) dietary advice
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Investigator)
Primary Purpose: Treatment
|Official Title:||The Canada-wide Human Nutrition Trialists' Network|
- Change from baseline of the maximum vessel wall volume of the carotid arteries [ Time Frame: At baseline and year 3 ]Assessed by MRI
- Intra-plaque hemorrhage (IPH) [ Time Frame: At baseline and year 3 ]Assessed by MRI
- Intra-plaque lipid (lipid-rich necrotic core) [ Time Frame: baseline and year 3 ]Assessed by MRI
- blood pressure and pulse rate [ Time Frame: At months 0, 3, 6, 12, 18, 24, 30, 36 ]
- initiation of statin therapy [ Time Frame: baseline and year 3 ]According to current CCS guidelines
- LDL-cholesterol [ Time Frame: At months, 0, 3, 6, 12, 18, 24, 30, 36 ]
- HDL-cholesterol [ Time Frame: months 0, 3, 6, 12, 18, 24, 30, 36 ]
- C-reactive protein (CRP) [ Time Frame: At months 0, 12, 24, and 36 ]
- The Medical Outcomes Study 36-Item Short Form Questionnaire (SF-36) [ Time Frame: Months 0 and 36 ]Survey on quality of life.
- Genetic whole genome testing [ Time Frame: month 0 ]One time sample collection of buffy coat white cells for future analysis
- satiety of the test and control diet [ Time Frame: Months 0, 3, 6, 12, 18, 24, 30, 36 ]Participants will assess their level of satiety on the test/control diet at each visit using a 9-point bipolar semantic scale ranging from -4 (being starved/ feeling weak and faint with hunger) to +4 (being Painfully full) with 0 being neutral (ie don't mind eating a little more or less).
- Palatability of the test / control diets [ Time Frame: Months 3, 6, 12, 18, 24, 30, and 36 ]The palatability of the diet will by measured using a numerical scale of 1 to 10 (1= strongly dislike and 10 = like very much).
|Primary Completion Date:||December 2014 (Final data collection date for primary outcome measure)|
Experimental: Portfolio Plus Diet
Participants will be advised to follow a low glycemic index dietary portfolio. Specifically, the advice will be to limit saturated fat (to <7% of total calories and cholesterol to <200 mg/d) plus inclusion of viscous fibres, soy protein, plant sterols and nuts, 5% extra monounsaturated fat and selection of low glycemic index foods; emphasizing current recommendations for fruit and vegetable intakes (5-10 servings/d)
Behavioral: Portfolio Plus Diet
Foods on the Portfolio Plus plan will contribute 9 g/1000 kcal viscous fibre as β-glucan (oats, barley, oat bran bread and soups) and psyllium (cereal), 1 g plant sterol/1000 kcal diet (in sterol margarine), 22.5 g soy protein/1000 kcal (soy burgers, dogs, links, other soy meat analogues, soy milks, yogurts and cheese) and additional sources of plant proteins from pulses (eg. lentils, chickpeas, beans, etc); and 22.5 g almonds or equivalent of other nuts/1000 kcal and increase MUFA (as olive and canola oils, avocados, nuts, margarine and salad dressings). The glycemic index will be reduced from 83 to 70 GI units (bread scale)
Active Comparator: DASH-like (high fibre) diet
The DASH-like dietary advice will emphasize a diet of whole grains, low-fat dairy and current recommendations for fruit and vegetables (5-10 servings/day)
Behavioral: DASH-like (high fibre) dietary advice
Dietary advice will be given to encourage intake of whole grain foods (brown rice, whole wheat breads, muffins and breakfast cereals); to reduce red meat consumption, choose low fat dairy foods and a control margarine
Other Name: high fibre diet
As Western populations age and as body weight increases, the need for dietary strategies to reduce Coronary Heart Disease (CHD) risk continues. The investigators are now in a position to put together a dietary approach which will be a significant advance over current dietary advice for CHD risk reduction. The investigators believe this study using imaging and functional techniques is now needed to 1) demonstrate an improvement in estimated CHD risk based on anatomical changes rather than serum risk factors. 2) encourage popular uptake and clinical use of this combination dietary strategy and 3) stimulate a larger longer term trial with CHD events.
Participants for this study will be recruited in 4 academic centres across Canada (Quebec, Toronto, Winnipeg and Vancouver). They will be in the low or moderate risk category based on the current Canadian Cardiovascular Society's (CCS) Guidelines 2012 and would normally be considered for initial treatment with lifestyle only. All participants will first be screened by ultrasound for the presence of plaque in the carotid arteries and will then be randomized to one of the 2 treatment arms: Portfolio Plus diet (test) or modified DASH diet (control), both given as routine clinical advice with follow up visits at 3-month intervals for 6 months and then twice yearly for the remainder of the 3 year trial.
Prior to starting either diet, participants will undergo screening ultrasound examination of both right and left carotids to enable selection of those individuals whose intima-media thickness would be 5-30% below the cut point considered by the Mannheim Consensus as relevant arterial thickening to ensure a relatively low risk group, yet with some measurable arterial thickening. The main outcome will be MRI assessment of maximum vessel wall volume. This assessment will be repeated at year 3. It will be emphasized at the outset that both the dietary portfolio and the DASH-like diets have been associated with benefits in terms of cholesterol reduction to provide equal encouragement for those randomized to the test and control groups. Portfolio and DASH-like dietary advice will consist of half hour individual sessions with the dietitian at baseline, 3, and 6 months and then at 6-month intervals. Prior to starting each diet, instruction will be given on achieving the dietary goals.
At follow-up visits, the participants' completed 7-day diet records will be discussed and the original advice reinforced. Every effort will be made to obtain study blood samples and carotid imaging data from all subjects at the designated times regardless of adherence to the dietary aspects of the study protocol. All subjects will be included in the intention-to-treat analysis.
Please refer to this study by its ClinicalTrials.gov identifier: NCT02078635
|Canada, British Columbia|
|Healthy Heart Lipid Clinic, St. Paul's Hospital|
|Vancouver, British Columbia, Canada, V6Z 1Y6|
|Richardson Center for Functional Foods and Nutraceuticals and the St. Boniface Hospital Cardiovascular Center, University of Manitoba|
|Winnipeg, Manitoba, Canada, R3T 6C5|
|Risk Factor Modification Centre, St. Michael's Hospital|
|Toronto, Ontario, Canada, M5C 2T2|
|Institute of Nutraceuticals and Functional Foods and the Quebec Heart and Lung Institute, Laval University|
|Quebec City, Quebec, Canada, G1V 4G2|
|Principal Investigator:||David J Jenkins, MD||St. Michael's Hospital / University of Toronto|
|Study Director:||Benoit Lamarche, PhD||Laval University|
|Study Director:||Peter Jones, PhD||University of Manitoba|
|Study Director:||Jiri Frohlich, MD||University of British Columbia|