Dietary Intervention and Vascular Function (DIVAS)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Julie Lovegrove, University of Reading
ClinicalTrials.gov Identifier:
NCT01478958
First received: November 16, 2011
Last updated: June 12, 2014
Last verified: June 2014
  Purpose

It is well established that diet plays an important role in both the development and progression of heart disease. Different types of dietary fat have varying effects on heart disease risk factors. The elasticity of an individual's blood vessels is strongly associated with heart disease risk and recent evidence suggests that dietary manipulation may influence elasticity of the blood vessels with dietary fat (including saturated, monounsaturated and polyunsaturated fatty acids) as a potentially important modulator. Substantial evidence exists on the effects of monounsaturated fats (type of fatty acids mainly found in olive and rapeseed oil), n-6 polyunsaturated fats (type of polyunsaturated fatty acids found in vegetable oils) and saturated fat (found mainly in animal derived products) on lipid levels. However, the influence of these dietary fats on the elasticity of blood vessels remains unclear.The main purpose of the DIVAS study is to determine the effects of the substitution of saturated fats with either n-6 polyunsaturated or monounsaturated fats on blood vessel elasticity and to determine the effects of these different dietary fats on other risk factors for heart disease including lipoproteins and inflammatory biomarkers.


Condition Intervention
Cardiovascular Disease
Dietary Supplement: SFA diet
Dietary Supplement: MUFA diet
Dietary Supplement: n-6 PUFA diet

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Prevention
Official Title: The Effects of the Substitution of Dietary SFA With n-6 PUFA or MUFA on Vascular Function

Resource links provided by NLM:


Further study details as provided by University of Reading:

Primary Outcome Measures:
  • Percent Change in Flow Mediated Dilatation (FMD) [ Time Frame: Baseline, 4 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Cardiovascular Risk Factors (Lipids, Inflammatory Markers, Indices of Insulin Resistance, Cell Microparticles, Endothelial Progenitor Cells) [ Time Frame: 4 months ] [ Designated as safety issue: No ]
    Data for fasting serum lipids (total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), TC:HDL-C ratio, low-density lipoprotein cholesterol (LDL-C), triacylglycerol (TAG)).

  • 24-hour Ambulatory Blood Pressure [ Time Frame: 4 months ] [ Designated as safety issue: No ]
    24-hour, daytime and night-time measures of systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP; SBP-DBP) and heart rate (HR)

  • Vascular Stiffness by Pulse Wave Velocity (PWV), Pulse Wave Analysis (PWA) and Digital Volume Pulse (DVP) [ Time Frame: 4 months ] [ Designated as safety issue: No ]
    PWV (m/s) PWA produces Augmentation Index (AIx; %) DVP produces Stiffness Index (SI; m/s) and Reflection Index (RI; %)

  • Microvascular Reactivity (Laser Doppler Imaging With Iontophoresis) [ Time Frame: 4 months ] [ Designated as safety issue: No ]
    Laser Doppler imaging (LDI) with iontophoresis of acetylcholine (Ach; endothelium-dependent vasodilation) and sodium nitroprusside (SNP; endothelium-independent vasodilation).


Enrollment: 202
Study Start Date: May 2010
Study Completion Date: October 2012
Primary Completion Date: October 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: high saturated fat diet Dietary Supplement: SFA diet
Volunteers are following a high saturated fat diet for a 4-month period
Experimental: high monounsaturated fat diet Dietary Supplement: MUFA diet
Volunteers are following a high monounsaturated fat diet for a 4-month period
Experimental: high n-6 polyunsaturated fat diet Dietary Supplement: n-6 PUFA diet
Volunteers are following a high n-6 polyunsaturated fat diet for a 4-month period

  Eligibility

Ages Eligible for Study:   21 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

Adults should have a relative risk (RR) of > 1.5 of developing cardiovascular disease (CVD) based on presenting with at least one recognised risk factor for CVD:

  • total cholesterol (TC) > 6.0 mmol/l
  • HDL cholesterol (HDLC) ≤ 1.0 mmol/l male, ≤ 1.3 mmol/l female
  • Glucose ≥ 6 mmol/l
  • Stage 1 hypertension or above i.e. a systolic BP ≥ 140 mmHg, diastolic BP ≥ 90 mmHg
  • BMI 28-35 kg/m2
  • waist >102 cm male or > 84 cm female
  • Adults with a first degree relative with either a history of premature CVD - age of onset younger than 55 y in fathers, sons or brothers or younger than 65 y in mothers, daughters or sisters, or type 2 diabetes.

Exclusion Criteria:

  • having suffered a myocardial infarction/stroke in the past 12 months
  • diabetic (diagnosed or fasting glucose > 7 mmol/l) or suffer from other endocrine disorders
  • suffering from renal or bowel disease or have a history of choleostatic liver or pancreatitis
  • on drug treatment for hyperlipidaemia, hypertension, inflammation or hypercoagulation
  • no history of alcohol abuse
  • planning or on a weight reducing regime
  • taking any fish oil, fatty acid or vitamin and mineral supplements
  • pregnant, lactating or planning a pregnancy
  • smokers
  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: NCT01478958

Locations
United Kingdom
Department of Food and Nutritional Sciences, University of Reading
Reading, Berkshire, United Kingdom, RG6 6AP
University of Reading
Reading, Berkshire, United Kingdom, RG6 6AP
Sponsors and Collaborators
University of Reading
Investigators
Principal Investigator: Julie A Lovegrove, BSc PhD RNutr University of Reading
  More Information

No publications provided by University of Reading

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Julie Lovegrove, Professor, University of Reading
ClinicalTrials.gov Identifier: NCT01478958     History of Changes
Other Study ID Numbers: N02044
Study First Received: November 16, 2011
Results First Received: May 13, 2014
Last Updated: June 12, 2014
Health Authority: United Kingdom: Food Standards Agency and Department of Health

Keywords provided by University of Reading:
fatty acids
cardiovascular disease
vascular function
microparticles

Additional relevant MeSH terms:
Cardiovascular Diseases

ClinicalTrials.gov processed this record on October 20, 2014