The Impact of Fish-oil Fatty Acids on Postprandial Vascular Reactivity (FOFA)
|Cardiovascular Physiological Phenomena Endothelial Nitric Oxide Synthase Eicosapentaenoic Acid Docosahexaenoic Acid (All-Z Isomer)||Dietary Supplement: EPA Dietary Supplement: DHA Dietary Supplement: Placebo|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
|Official Title:||The Impact of Fish-oil Fatty Acids on Postprandial Vascular Reactivity|
- Endopat [ Time Frame: Change from baseline at 4 hours postprandially ]EndoPat is an easy to use and rapid technique which has been validated against other clinically accepted measures of endothelial function such as Flow Mediated Dilation and Coronary Blood Flow measured by angiography alongside acetylcholine infusion. EndoPat has also been shown to correlate with multiple known CVD risk factors and to be predictive of future cardiovascular events. In addition, EndoPat will be utilised alongside oral administration of nitroglycerin in order to establish if peripheral arterial tone is altered in response to EPA or DHA in a non-Nitric Oxide dependent manner. EndoPAT produces a reactive hyperaemic index score which is indicative of the endothelial's capacity to produce NO, which itself is indicative of general endothelial function. EndoPAT will be assessed using a standardised methodology developed by Itamar Medical, which involves measuring changes in dilation in response to induced hyperaemia.
- Pulse Wave Velocity [ Time Frame: Change from baseline at 4 hours postprandially ]Pulse Wave Velocity (PWV) analysis will also be utilised in order to measure arterial stiffness. PWV analysis will allow several non-invasive measurements to be taken simultaneously including PWV, which is an established index of arterial stiffness, and augmentation index, an indirect measure of arterial stiffness which is dependent on wave-reflections and independent of pulse pressure. PWV and associated measures will be measured using methodology developed by Skidmore medical. PWV is measured in m/sec while augmentation index is measured as a % of augmentation (of central aortic pressure by a reflected pulse wave).
|Study Start Date:||September 2012|
|Study Completion Date:||October 2013|
|Primary Completion Date:||October 2013 (Final data collection date for primary outcome measure)|
High fat meal containing DHA rich oil.
Dietary Supplement: DHA
High fat meal containing DHA
High fat meal containing EPA.
Dietary Supplement: EPA
High fat meal containing EPA
Placebo Comparator: Control
High fat meal with no/negligable omega-3 fatty acid content.
Dietary Supplement: Placebo
High fat meal containing negligible EPA/DHA content
A loss of vascular reactivity and increased vascular tone is being increasingly recognised as a significant cardiovascular disease (CVD) risk factor and highly predictive of future CVD events. A previous study by our group has shown the inclusion of a fish oil mixture administered alongside a high fat meal preserves postprandial vascular function in healthy men . In this three arm, placebo controlled cross over study, the impact of individual fatty acids contained within fish-oil on postprandial vascular reactivity (measured at 4 hour post test meal) will be assessed for the first time. Clinical measurements of vascular function which correlate with CVD risk factors and are predictive of future CVD events will be undertaken in order to assess any potentially beneficial effects. In addition plasma samples will be taken at 0 and 4 hours to determine the change in concentration of modulators of vascular tone. Accordingly, our nutrients of interest which will be administered in the intervention arms of the study, will be present in this lipoprotein rich fraction. By exposing cells in culture to these EPA- and DHA-enriched lipoproteins, mechanisms underlying the vascular response in our human volunteers will be investigated. Finally we will measure the plasma fatty acid profile to confirm that circulating concentrations of EPA and DHA are increasing postprandially according to intake.
As it is now recognised that genetic variation, in addition to being an important determinant of the risk of all known chronic diseases, plays a large part in determining an individual's response to dietary change, DNA will be extracted from whole blood taken at the clinical screening and stored for subsequent genotyping for variants likely to be important in the regulation of EPA and DHA metabolism and vascular tone. Although the current study will not be fully powered to generate definite conclusion regarding genotype*diet interactions, it will serve to generate pilot data for future studies.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01692431
|Norwich Medical School|
|Norwich, United Kingdom, NR47TJ|
|Principal Investigator:||Anne Marie Minihane, PhD||University of East Anglia|