Dietary Intervention and Vascular Function

Not Applicable

Completed

Conditions: Cardiovascular Disease

Interventions: Dietary Supplement: SFA diet
Dietary Supplement: n-6 PUFA diet
Dietary Supplement: MUFA diet

Registration Number: NCT01478958

Lead Sponsor: University of Reading

Brief 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.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 202

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

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
high saturated fat diet	SFA diet	-
high n-6 polyunsaturated fat diet	n-6 PUFA diet	-
high monounsaturated fat diet	MUFA diet	-

Primary Outcome Measures

Name	Time	Method
Percent Change in Flow Mediated Dilatation (FMD)	Baseline, 4 months

Secondary Outcome Measures

Name	Time	Method
24-hour Ambulatory Blood Pressure	4 months	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)	4 months	PWV (m/s) PWA produces Augmentation Index (AIx; %) DVP produces Stiffness Index (SI; m/s) and Reflection Index (RI; %)
Cardiovascular Risk Factors (Lipids, Inflammatory Markers, Indices of Insulin Resistance, Cell Microparticles, Endothelial Progenitor Cells)	4 months	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)).
Microvascular Reactivity (Laser Doppler Imaging With Iontophoresis)	4 months	Laser Doppler imaging (LDI) with iontophoresis of acetylcholine (Ach; endothelium-dependent vasodilation) and sodium nitroprusside (SNP; endothelium-independent vasodilation).

Trial Locations

Locations (2): Department of Food and Nutritional Sciences, University of Reading
🇬🇧
Reading, Berkshire, United Kingdom
University of Reading
🇬🇧
Reading, Berkshire, United Kingdom