Vasoprotective Activities of Low-Fat Milk in Individuals With Metabolic Syndrome

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Richard Bruno, University of Connecticut
ClinicalTrials.gov Identifier:
NCT01411293
First received: August 4, 2011
Last updated: January 3, 2014
Last verified: January 2014
  Purpose

The purpose of this study is to define whether the acute consumption of low-fat milk protects against postprandial vascular endothelial dysfunction by reducing oxidative stress responses that limit nitric oxide bioavailability to the vascular endothelium. The investigators hypothesis is that the consumption of low-fat milk will improve postprandial vascular endothelial function in an oxidative stress-dependent manner that allows greater nitric oxide (NO) bioavailability. The objectives of this study are to 1) examine improvements in postprandial vascular endothelial function in response to low-fat milk ingestion, 2) define low-fat milk-mediated improvements in circulating biomarkers of redox status, and 3) define the mechanism by which low-fat milk improves NO bioavailability. Collectively, the successful completion of these studies is expected to define NO mediated activities of low-fat milk that protect against vascular endothelial dysfunction in individuals at high risk for developing CVD.


Condition Intervention
Cardiovascular Disease
Metabolic Syndrome
Obesity
Other: Low-Fat Milk
Other: Rice Milk

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Vasoprotective Activities of Low-Fat Milk in Individuals With Metabolic Syndrome

Resource links provided by NLM:


Further study details as provided by University of Connecticut:

Primary Outcome Measures:
  • endothelial function [ Time Frame: 3 hours ] [ Designated as safety issue: No ]
    Brachial artery flow-mediated dilation will be assessed at 30 min intervals during a 3 hour postprandial period


Secondary Outcome Measures:
  • Biomarkers of oxidative stress and nitric oxide metabolism [ Time Frame: 3 hours ] [ Designated as safety issue: No ]
    At 30 min intervals throughout a 3 hour postprandial period, biomarkers of oxidative stress (glutathione, malondialdehyde, nitrotyrosine, and antioxidants) as well as nitric oxide metabolism (arginine, asymmetric dimethylarginine, and nitric oxide metabolites) will be evaluated.


Enrollment: 21
Study Start Date: August 2011
Study Completion Date: October 2013
Primary Completion Date: August 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Low-Fat Dairy
Participants will ingest 2 cups of low-fat milk on 1 occasion prior to measure postprandial changes in vascular function
Other: Low-Fat Milk
Participants will ingest 2 cups of low-fat milk on 1 occasion.
Active Comparator: Rice Milk
Participants will ingest 2 cups of rice milk on 1 ocassion prior to measuring postprandial vascular function
Other: Rice Milk
Participants will ingest 2 cups of rice milk on 1 occasion.

Detailed Description:

Cardiovascular disease (CVD) is the leading cause of death in the United States, accounting for ~830,000 deaths annually. Oxidative stress and inflammatory responses are fundamental mechanisms leading to vascular endothelial dysfunction because of their role in reducing nitric oxide (NO) bioavailability. Greater intakes of dairy foods have been associated with a lower incidence of CVD-related morbidity. Although the mechanisms by which dairy protects against CVD remain unclear, epidemiological and experimental evidence suggest that the concerted actions of bioactive milk-derived peptides and micronutrients may protect against hypertension and future CVD risk by improving vascular endothelial function. Therefore, the objective of this study is to define the mechanisms by which the acute consumption of low-fat milk protects against postprandial vascular endothelial dysfunction by reducing oxidative stress responses that limit NO bioavailability to the vascular endothelium. In this study, participants having the metabolic syndrome will ingest low-fat milk or rice milk on a single occasion. Then, vascular function and biomarkers of oxidative stress and NO metabolism will be monitored at 30 min intervals throughout a 180 min postprandial period. Collectively, these studies will help identify how postprandial vascular function is regulated in individuals at high-risk for CVD, and whether low-fat dairy consumption can be used as a strategy to better improve vascular function.

  Eligibility

Ages Eligible for Study:   18 Years to 50 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • specific criteria of the metabolic syndrome (waist circumference (102-137 or 88-123 cm for men and women, respectively), fasting triglycerides 150-300 mg/dL, and fasting glucose (110-180 mg/dL)
  • BMI: >30 kg/m2,
  • non-dietary supplement users for >2-mo
  • no use of any prescription or over-the-counter medications known to affect vasodilatory responses
  • no known history of vascular disease
  • nonsmokers
  • resting blood pressure <140 mmHg
  • not taking any medications that control hypertension

Exclusion Criteria:

  • lactose-intolerant
  • excessive alcohol consumption (>3 drinks/d or >10 drinks/wk)
  • >7 h/wk of aerobic activity
  • use of medications known to affect carbohydrate or lipid/lipoprotein metabolism
  • regular use of any anti-inflammatory medications (e.g. aspirin, non-steroidal anti-inflammatory drugs) or over-the-counter aids (e.g. fish oils)
  • women who are pregnant, lactating, and have initiated or changed birth control in the past 3-mo
  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: NCT01411293

Locations
United States, Connecticut
University of Connecticut
Storrs, Connecticut, United States, 06269
Sponsors and Collaborators
University of Connecticut
Investigators
Principal Investigator: Richard S Bruno, PhD, RD University of Connecticut
  More Information

Publications:
Responsible Party: Richard Bruno, Principal Investigator, University of Connecticut
ClinicalTrials.gov Identifier: NCT01411293     History of Changes
Other Study ID Numbers: H11-124
Study First Received: August 4, 2011
Last Updated: January 3, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by University of Connecticut:
cardiovascular disease
oxidative stress
dairy consumption
metabolic syndrome
obesity
endothelial function

Additional relevant MeSH terms:
Cardiovascular Diseases
Metabolic Syndrome X
Obesity
Syndrome
Body Weight
Disease
Glucose Metabolism Disorders
Hyperinsulinism
Insulin Resistance
Metabolic Diseases
Nutrition Disorders
Overnutrition
Overweight
Pathologic Processes
Signs and Symptoms

ClinicalTrials.gov processed this record on October 21, 2014