Dietary Flaxseed Reduces Central Aortic Blood Pressure Without Cardiac Involvement but Through Changes in Plasma Oxylipins

Stephanie P B Caligiuri; Delfin Rodriguez-Leyva; Harold M Aukema; Amir Ravandi; Wendy Weighell; Randolph Guzman; Grant N Pierce

doi:10.1161/HYPERTENSIONAHA.116.07834

Dietary Flaxseed Reduces Central Aortic Blood Pressure Without Cardiac Involvement but Through Changes in Plasma Oxylipins

Hypertension. 2016 Oct;68(4):1031-8. doi: 10.1161/HYPERTENSIONAHA.116.07834. Epub 2016 Aug 15.

Authors

Stephanie P B Caligiuri¹, Delfin Rodriguez-Leyva¹, Harold M Aukema¹, Amir Ravandi¹, Wendy Weighell¹, Randolph Guzman¹, Grant N Pierce²

Affiliations

¹ From the Canadian Centre for Agri-food Research in Health and Medicine (S.P.B.C., D.R.-L., H.M.A., G.N.P.), Institute of Cardiovascular Sciences, St Boniface Hospital (S.P.B.C., D.R.-L., A.R., G.N.P.), Department of Physiology and Pathophysiology (S.P.B.C., D.R.-L., A.R., G.N.P.), Department of Internal Medicine (D.R.-L., A.R.), Department of Human Nutritional Sciences (H.M.A.), and Department of Surgery (W.W., R.G.), University of Manitoba, Winnipeg, Manitoba, Canada.
² From the Canadian Centre for Agri-food Research in Health and Medicine (S.P.B.C., D.R.-L., H.M.A., G.N.P.), Institute of Cardiovascular Sciences, St Boniface Hospital (S.P.B.C., D.R.-L., A.R., G.N.P.), Department of Physiology and Pathophysiology (S.P.B.C., D.R.-L., A.R., G.N.P.), Department of Internal Medicine (D.R.-L., A.R.), Department of Human Nutritional Sciences (H.M.A.), and Department of Surgery (W.W., R.G.), University of Manitoba, Winnipeg, Manitoba, Canada. gpierce@sbrc.ca.

PMID: 27528063
DOI: 10.1161/HYPERTENSIONAHA.116.07834

Abstract

In the year-long FlaxPAD clinical trial (Flaxseed for Peripheral Artery Disease), dietary flaxseed generated a powerful reduction in brachial systolic and diastolic blood pressure in patients with peripheral artery disease. Oxylipins were implicated as potential mechanistic mediators. However, the ability of flaxseed to impact central aortic hypertension, arterial stiffness, or cardiac performance was not investigated. Additionally, the relationship between central blood pressure (cBP) and oxylipins was not elucidated. Therefore, radial tonometry and pulse wave analysis were used to measure cBP and cardiac function in the FlaxPAD population (n=62). Plasma oxylipins were analyzed with high-performance liquid chromatography mass spectrometry. In patients with high blood pressure at baseline, the average decrease in central systolic and diastolic blood pressures versus placebo was 10 and 6 mm Hg, respectively. Flaxseed did not significantly impact augmentation index or other cardiac function indices. Alternatively, the data support several specific oxylipins as potential mediators in the antihypertensive properties of flaxseed. For example, every 1 nmol/L increase in plasma 16-hydroxyeicosatetraenoic acid increased the odds of higher central systolic and diastolic blood pressures by 12- and 9-fold, respectively. Every 1 nmol/L increase in plasma thromboxane B2 and 5,6-dihydroxyeicosatrienoic acid increased the odds of higher cBP by 33- and 9-fold, respectively. Flaxseed induced a decrease in many oxylipins, which corresponded with a reduced risk of elevated cBP. These data extend the antihypertensive properties of flaxseed to cBP without cardiac involvement but rather through oxylipins. This study provides further support for oxylipins as therapeutic targets in hypertension.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00781950.

Keywords: central blood pressure; flaxseed; hypertension; nutrition; oxylipins; peripheral vascular disease; pulse wave analysis.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Analysis of Variance
Arterial Pressure / drug effects*
Blood Pressure Determination
Cardiovascular Diseases / prevention & control
Dietary Supplements*
Double-Blind Method
Female
Flax*
Humans
Hypertension / drug therapy
Hypertension / prevention & control
Logistic Models
Male
Middle Aged
Odds Ratio
Oxylipins / blood*
Peripheral Vascular Diseases / drug therapy*
Peripheral Vascular Diseases / physiopathology
Prospective Studies
Pulse Wave Analysis
Reference Values
Treatment Outcome

Substances

Oxylipins

Associated data

ClinicalTrials.gov/NCT00781950