Impact of Meal Fatty Acids on Postprandial Vascular Reactivity (DIVAS-2)

The Acute Effects of Meals Rich in Saturated, Monounsaturated and n-6 Polyunsaturated Fatty Acids on Vascular Function

Cardiovascular disease (CVD) is the leading cause of death in women. Premenopausal women have a lower risk of CVD compared with men of a similar age. However, the incidence of CVD increases greatly after the menopause. The risk of heart disease is strongly associated with the health of an individual's blood vessels. It is thought that changes to the type of fat the investigators eat in their diet may affect the normal functioning and elasticity of the blood vessels, as well as affect cholesterol levels in the blood. Types of fat in the diet include monounsaturated fats (found mainly in olive oil), n-6 polyunsaturated fats (found mainly in sunflower oil) and saturated fats (found mainly in dairy products, such as butter and cheese). Since the investigators are in the fed (or postprandial) state for up to 18 hours of the day, it is important to see how these different fats affect the investigators blood vessels and blood fats over the course of the day after eating a meal. The aim of this study is to determine how consuming meals rich in saturated fats, n-6 polyunsaturated fats or monounsaturated fats influence the normal functioning and elasticity of the blood vessels throughout the day in postmenopausal women. A secondary aim is to determine the effects of these different dietary fats on a range of accepted heart disease risk markers including circulating levels of fats (lipids) and glucose in the blood.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Disease
• Intervention / Treatment: Dietary supplement: Saturated fat; Dietary supplement: Monounsaturated fat; Dietary supplement: n-6 polyunsaturated fat

• Study Type: Interventional
• Enrollment (Actual): 32
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Berkshire
    • Reading, Berkshire, United Kingdom, RG6 6AP
      • University of Reading

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Postmenopausal (not menstruated for at least 1 year)
• Plasma triacylglycerol (TAG) between 0.8 and 4.0 mmol/l
• Body mass index (BMI) between 18-35 kg/m2
• Total cholesterol (TC): <8 mmol/l
• Systolic blood pressure <160 mmHg and diastolic blood pressure <100 mmHg
• Non-smoker

Exclusion Criteria:

• Having suffered a myocardial infarction/stroke in the past 12 months
• Diabetic (diagnosed as fasting blood glucose >7 mmol/l) or suffering from other endocrine disorders
• Suffering from renal or bowel disease or have a history of cholestatic liver or pancreatitis
• On drug treatment for hyperlipidaemia, hypertension, inflammation or hypercoagulation
• History of alcohol abuse
• On hormone replacement therapy (HRT)
• Planning or on a weight reducing regime
• Taking nutritional supplements (e.g. fish oil, calcium)
• Anaemic: haemoglobin <11.5 g/dl

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Meal rich in saturated fats; Subjects are asked to consume a breakfast (0 min) and lunch (330 min) rich in saturated fats	Dietary supplement: Saturated fat; Other Names: SFA
Experimental: Meal rich in monounsaturated fats; Subjects are asked to consume a breakfast (0 min) and lunch (330 min) rich in monounsaturated fats	Dietary supplement: Monounsaturated fat; Other Names: MUFA
Experimental: Meal rich in n-6 polyunsaturated fats; Subjects are asked to consume a breakfast (0 min) and lunch (330 min) rich in n-6 polyunsaturated fats	Dietary supplement: n-6 polyunsaturated fat; Other Names: n-6 PUFA

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change from baseline in vascular reactivity measured by flow-mediated dilatation (FMD)	Acute study: measured at 0 (baseline), 180, 300 and 420 min

Secondary Outcome Measures

Outcome Measure	Time Frame
Change from baseline in vascular reactivity measured by laser Doppler imaging with iontophoresis of acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent)	Acute study: measured at 0 (baseline), 240 and 450 min
Change from baseline in plasma lipids (primarily triacylglycerol, apolipoprotein B and non-esterified fatty acids)	Acute study: taken at 30 min intervals between 0 min (baseline) and 480 min
Change from baseline in arterial stiffness measured by digital volume pulse (stiffness index and reflection index)	Acute study: taken at 0 (baseline), 240 amd 450 min
Change from baseline in blood pressure (systolic blood pressure, diastolic blood pressure and pulse pressure)	Acute study: taken at 0 (baseline), 240 and 450 min
Change from baseline in markers of insulin resistance (glucose, insulin, indices of insulin resistance/sensitivity)	Acute study: taken at 30 min intervals between 0 min (baseline) and 480 min
Change from baseline in nitric oxide (total plasma nitrates and nitrites)	Acute study: 0 (baseline), 180, 300 and 420 min
Change from baseline in plasma markers of endothelial activation (e.g. E-selectin, P-selectin, vascular cell adhesion molecule (VCAM-1))	Acute study: 0 (baseline), 180, 300 and 420 min
Change from baseline in plasma phospholipid fatty acid composition	Acute study: 0 (baseline), 180, 300 and 420 min

Collaborators and Investigators

• Sponsor: University of Reading
• Collaborators: Department of Health, United Kingdom

Publications and helpful links

General Publications

• Rathnayake KM, Weech M, Lovegrove JA, Jackson KG. Glu298Asp (rs1799983) Polymorphism Influences Postprandial Vascular Reactivity and the Insulin Response to Meals of Varying Fat Composition in Postmenopausal Women: Findings from the Randomized, Controlled Dietary Intervention and VAScular function (DIVAS)-2 Study. J Nutr. 2021 Apr 8;151(4):848-856. doi: 10.1093/jn/nxaa394.
• Rathnayake KM, Weech M, Jackson KG, Lovegrove JA. Meal Fatty Acids Have Differential Effects on Postprandial Blood Pressure and Biomarkers of Endothelial Function but Not Vascular Reactivity in Postmenopausal Women in the Randomized Controlled Dietary Intervention and VAScular function (DIVAS)-2 Study. J Nutr. 2018 Mar 1;148(3):348-357. doi: 10.1093/jn/nxx042.

Study record dates

Study Major Dates

• Study Start: June 1, 2014
• Primary Completion (Actual): September 1, 2015
• Study Completion (Actual): September 1, 2015

Study Registration Dates

• First Submitted: May 15, 2014
• First Submitted That Met QC Criteria: May 21, 2014
• First Posted (Estimate): May 22, 2014

Study Record Updates

• Last Update Posted (Estimate): December 3, 2015
• Last Update Submitted That Met QC Criteria: December 2, 2015
• Last Verified: December 1, 2015

More Information

Terms related to this study

• Keywords: Cardiovascular disease; Insulin resistance; Blood pressure; Vascular function; Fatty acids; Plasma lipids; Endothelial activation
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: 024/0036