Dietary Intervention and Vascular Function

Cardiovascular Disease Clinical Trial

— DIVAS  

Official title:

The Effects of the Substitution of Dietary SFA With n-6 PUFA or MUFA on Vascular Function

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01478958
• Other study ID #: N02044
• Status: Completed
• Phase: N/A
• First received: November 16, 2011
• Last updated: June 12, 2014
• Start date: May 2010
• Est. completion date: October 2012

Study information

• Verified date: June 2014
• Source: University of Reading
• Contact: n/a
• Is FDA regulated: No
• Health authority: United Kingdom: Food Standards Agency and Department of Health
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 202
• Est. completion date: October 2012
• Est. primary completion date: October 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 21 Years to 60 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Cardiovascular Disease
• Cardiovascular Diseases

Intervention

Dietary Supplement:
• SFA diet
Volunteers are following a high saturated fat diet for a 4-month period
• MUFA diet
Volunteers are following a high monounsaturated fat diet for a 4-month period
• n-6 PUFA diet
Volunteers are following a high n-6 polyunsaturated fat diet for a 4-month period

Locations

Country	Name	City	State
United Kingdom	Department of Food and Nutritional Sciences, University of Reading	Reading	Berkshire
United Kingdom	University of Reading	Reading	Berkshire

Sponsors (1)

Lead Sponsor	Collaborator
University of Reading

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Percent Change in Flow Mediated Dilatation (FMD)		Baseline, 4 months	No
Secondary	Cardiovascular Risk Factors (Lipids, Inflammatory Markers, Indices of Insulin Resistance, Cell Microparticles, Endothelial Progenitor Cells)	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)).	4 months	No
Secondary	24-hour Ambulatory Blood Pressure	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)	4 months	No
Secondary	Vascular Stiffness by Pulse Wave Velocity (PWV), Pulse Wave Analysis (PWA) and Digital Volume Pulse (DVP)	PWV (m/s) PWA produces Augmentation Index (AIx; %) DVP produces Stiffness Index (SI; m/s) and Reflection Index (RI; %)	4 months	No
Secondary	Microvascular Reactivity (Laser Doppler Imaging With Iontophoresis)	Laser Doppler imaging (LDI) with iontophoresis of acetylcholine (Ach; endothelium-dependent vasodilation) and sodium nitroprusside (SNP; endothelium-independent vasodilation).	4 months	No