Impact of Dairy Consumption on Hypertension: a Clinical Study (PLAT)

This study has been completed.
Sponsor:
Collaborator:
Dairy Farmers of Canada
Information provided by (Responsible Party):
Patrick Couture, Laval University
ClinicalTrials.gov Identifier:
NCT01776216
First received: January 21, 2013
Last updated: February 6, 2014
Last verified: February 2014
  Purpose

Hypertension and endothelial dysfunction are being increasingly recognized as key etiological factors in the development of atherosclerosis and subsequent cardiovascular disease (CVD). A substantial body of evidence indicates that treating patients with elevated blood pressure (BP) leads to marked reduction in the risk of stroke, myocardial infarction, heart failure, and renal failure. There is also accumulating evidence associating endothelial dysfunction, which is defined as incapacity of the arteries to vasodilate when required, to elevated BP and an increased risk of CVD.

While there are more and more studies on how diet affects BP in healthy subjects, the impact of dairy consumption per se on both endothelial function and ambulatory BP has not been well characterized in patients with established essential hypertension. Therefore, the general objective of the study is to investigate in a single-blind randomized controlled study the impact of dairy consumption on ambulatory BP and endothelial function in subjects with mild to moderate essential hypertension.


Condition Intervention
Hypertension
Cardiovascular Diseases
Other: Dairy diet
Other: Control diet

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Impact of Dairy Consumption on Hypertension: a Clinical Study.

Resource links provided by NLM:


Further study details as provided by Laval University:

Primary Outcome Measures:
  • Change in mean daytime systolic blood pressure [ Time Frame: At the fisrt visit of the study (screening) and at the end of the two 4-weeks diets (week 4 and week 12) ] [ Designated as safety issue: No ]
    Mean daytime systolic blood pressure will be measured by 24-h ambulatory blood pressure monitoring using the Spacelabs 90207 (Spacelabs, Inc., Redmond, WA)


Secondary Outcome Measures:
  • Change in mean daytime diastolic blood pressure [ Time Frame: At the first visit of the study (screening) and at the end of the two 4-weeks diets (week 4 and week 12) ] [ Designated as safety issue: No ]
    Mean daytime diastolic blood pressure will be measured by 24-h ambulatory blood pressure monitoring using the Spacelabs 90207 (Spacelabs, Inc., Redmond, WA)

  • Change in endothelial function [ Time Frame: At the end of the two 4-weeks diets (week 4 and week 12) ] [ Designated as safety issue: No ]
    Digital pulse amplitude will be measured with a PAT device placed on the tip of each index finger (Endo-PAT2000, Itamar Medical, Caesarea, Israel)


Enrollment: 80
Study Start Date: August 2011
Study Completion Date: December 2013
Primary Completion Date: March 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Dairy diet
During the DAIRY diet, subjects will be asked to incorporate 3 servings of dairy into their everyday diet.
Other: Dairy diet
During the DAIRY diet, subjects will be asked to incorporate 3 servings of dairy: 375 ml of reduced fat milk (1% fat), 175 g of low fat yogurt (1.5% fat) and 30g of regular cheese (34% fat) into their every day diet.
Other Names:
  • Dairy products
  • Milk
  • Yogourt
  • Cheese
Placebo Comparator: Control diet
During the CONTROL diet of the study, participants will be asked to consume energy equivalent replacement products into their everyday diet.
Other: Control diet
During the CONTROL diet of the study, participants will be asked to consume energy equivalent replacement products (290 ml of fruit juice, 156 ml of vegetable juice, 1 homemade cookie, 20g of cashew).

Detailed Description:

The proposed research will be undertaken as a single-center randomized cross-over controlled study. A total of 80 men and women with mild to moderate essential hypertension but otherwise healthy will consume two 4-week diets, one rich in dairy and one without dairy, while consuming a diet low in saturated fat (<10% energy), in trans fat (<1% energy) and in cholesterol (<200 mg/day). During the DAIRY diet, subjects will be asked to incorporate 3 servings of dairy (milk, yogurt, cheese) into their every day diet. During the CONTROL arm of the study, participants will be asked to consume energy equivalent replacement products. The primary analysis consists in comparing mean daytime ambulatory BP values and endothelial function between the two treatments.

A 2-week stabilization run-in period will precede the randomization of participants. During this run-in period, participants will be asked and instructed to adapt their diet to a prudent dietary pattern low in saturated fat (<10% energy), in trans fat (<1% energy) and in cholesterol (<200 mg/day). The total amount of fat in the diet will not be restricted, with recommendations ranging from 25-35% of energy. However, substitution of saturated for unsaturated fat will be advocated. Sodium intake <2300 mg/d will also be recommended. Recommendations will also include advice on how to restrict the consumption of processed and energy dense foods. This 2-week run-in period will allow participants to familiarize themselves with the dietary recommendations used during the intervention per se. The two diets will be separated by a 4-week wash out period and will also consist to the prudent dietary pattern recommended. It must be stressed that foods will not be provided during the run-in and wash-out periods. These periods are imposed to minimize the inter- and intra-individual variability before and between the experimental phases.

  Eligibility

Ages Eligible for Study:   18 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Men and women aged between 18 and 70 years
  • Mean daytime systolic blood pressure ≥ 135 mm Hg and ≤ 160 mm Hg
  • Mean daytime diastolic blood pressure ≤ 110 mm Hg
  • Consumption of dairy products fewer than 2 servings per day

Exclusion Criteria:

  • Mean daytime systolic blood pressure > 160 mm Hg
  • Mean daytime diastolic blood pressure > 110 mm Hg
  • Dairy intake > 2 serving per day
  • Smokers (>1 cigarette/day)
  • Body weight variation >10% during the last 6 months prior to the study baseline
  • BMI >35 kg/m2
  • Previous history of cardiovascular disease, type 2 diabetes and monogenic dyslipidemia
  • Subject taking anti-inflammatory drugs
  • Subject with endocrine or gastrointestinal disorders
  • Allergy, intolerance or aversion to dairy
  • Clinical use of vitamin D or calcium supplements
  • Vegetarians
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01776216

Locations
Canada, Quebec
Institute of Nutraceuticals and Functional Foods (INAF)
Quebec City, Quebec, Canada, G1V 0A6
Sponsors and Collaborators
Laval University
Dairy Farmers of Canada
Investigators
Principal Investigator: Patrick Couture, MD,FRCP,PhD Laval University
  More Information

No publications provided

Responsible Party: Patrick Couture, MD, FRCP, PhD, Laval University
ClinicalTrials.gov Identifier: NCT01776216     History of Changes
Other Study ID Numbers: INAF-C11-02-163
Study First Received: January 21, 2013
Last Updated: February 6, 2014
Health Authority: Canada: Health Canada

Keywords provided by Laval University:
Endothelial function
Dairy

Additional relevant MeSH terms:
Cardiovascular Diseases
Hypertension
Vascular Diseases

ClinicalTrials.gov processed this record on August 20, 2014