Alpha-linolenic Acid and Blood Pressure (VASALA)
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|ClinicalTrials.gov Identifier: NCT02243969|
Recruitment Status : Completed
First Posted : September 18, 2014
Last Update Posted : March 22, 2016
Rationale: Increased intakes of n-3 long chain polyunsaturated fatty acids eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA), mainly found in fatty fish, are recommended for the prevention of coronary heart disease. Alpha-linolenic acid (ALA, C18:3n-3) is the most common vegetable-oil based n-3 fatty acid. Evidence exists that ALA supplementation can also have a protective effect on the development on cardiovascular disease, but may exert its cardio protective effects through different routes. The benefit may (partly) be due to blood pressure lowering. However, evidence for beneficial effects of ALA on blood pressure is conflicting. Therefore, we propose to investigate the effect of flaxseed oil, high in ALA, using a study powered on 24-hour blood pressure, in a population with high normal blood pressure and mild hypertension.
Objective: To study the effects of flaxseed oil, rich in ALA on 24h-ambulatory mean arterial pressure (MAP) in men and women with high-normal blood pressure and mild hypertension compared to high oleic sunflower oil, poor in ALA.
Study design: Using a double blind randomized, placebo-controlled parallel design, subjects will receive at random daily 10 g of flaxseed oil or a high-oleic acid sunflower oil (HOSF) as control for twelve weeks, with a run-in period of 14 days in advance.
Study population: 72 men and women, aged 40-70 years, with untreated high-normal blood pressure and stage I hypertension and a body mass index between 25 and 35 kg/m2 will participate in the run-in and intervention period. It is estimated that 144 subject have to be screened to find 72 subjects that will enter the run-in period.
Intervention: During the run-in period, subjects will receive daily 10 g of palm super olein oil. During the intervention period subjects receive either 10 g of HOSF or flaxseed oil. All oils are provided in bottles of 5 g, one will be consumed at breakfast or lunch and one at dinner.
Main study parameters/endpoints: The main study parameter is the change in 24h-ambulatory mean arterial pressure (MAP)
|Condition or disease||Intervention/treatment||Phase|
|Hypertension Lipid Metabolism Disorders||Dietary Supplement: Flaxseed oil Dietary Supplement: high oleic sunflower oil (HOSF)||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||62 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)|
|Official Title:||Effects of Alpha-linolenic Acid on 24h-ambulatory Mean Arterial Pressure in Untreated High-normal and Stage I Hypertensive Subjects|
|Study Start Date :||May 2014|
|Actual Primary Completion Date :||October 2015|
|Actual Study Completion Date :||October 2015|
|Experimental: flaxseed oil (rich in α-linolenic acid )||
Dietary Supplement: Flaxseed oil
The flaxseed oil will be provided in vials containing 5 g of oil, and should be taken for twelve weeks during the experimental period twice a day
|Placebo Comparator: high oleic sunflower oil||
Dietary Supplement: high oleic sunflower oil (HOSF)
The HOSF will be provided in vials containing 5 g of oil, and should be taken for twelve weeks during the experimental period twice a day
- 24h-ambulatory mean arterial pressure (MAP) [ Time Frame: Baseline and end of intervention period (week 2 and 14) ]Ambulatory blood pressure measurements will be performed using an automated blood pressure device with 15-minute intervals during the day and 30-minute intervals during the night.
- Postprandial flow mediated dilatation (FMD) [ Time Frame: End of intervention period (week 14) ]The brachial artery FMD will be measured in a subset (n=20 per group) of the study population. FMD will be measured before and 2 hours after a fat load.
- Night, day and early morning 24h-ambulatory MAP, SBP and DBP [ Time Frame: Baseline and end of intervention (week 2 and 14) ]Ambulatory blood pressure measurements will be performed using an automated blood pressure device with 15-minute intervals during the day and 30-minute intervals during the night.
- Systolic, diastolic and MAP office blood pressure [ Time Frame: Measured every visit (week 1,2,8,14) ]Each visit blood pressure will be measured in four-fold with 1-minute interval (the first measurement will be discarded and the last three measurement will be averaged) using a calibrated device.
- The fatty-acid profile of plasma phospholipids [ Time Frame: Baseline and end of intervention period (week 2 and 14) ]measured in fasting plasma samples
- Pulse wave velocity (PWV) [ Time Frame: Baseline and end of intervention period (week 2 and 14) ]PWV will be determined by extending data from standard brachial artery blood pressure measurements
- Retinal microvasculature [ Time Frame: Baseline and end of intervention period (week 2 and 14) ]Measured as AV-ratio and vessel diameter from digitized analogue fundus photographs
- Fasting and postprandial lipid and glucose metabolism [ Time Frame: Every visit (week 1,2,8,14) Postprandial in subset of n=20 per group ]Postprandial glucose at time point 15,30,45,60,90,120,180,240 minutes Postprandial lipids at time point 60, 120, 180, 240 minutes
- Fasting and postprandial serum biomarkers for low-grade systemic inflammation (hsCRP, IL-6) and endothelial function (sICAM-1, VCAM-1, MCP-1 and sE-Selectin) [ Time Frame: Every visit (week 1,2,8,14) Postprandial in subset of n=20 per group at time point 60, 120, 240 minutes ]
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02243969
|Maastricht University Medical Center|
|Maastricht, Limburg, Netherlands, 6229 ER|
|Principal Investigator:||Ronald P Mensink, PhD||Maastricht University Medical Center|