Effects of watermelon supplementation on aortic blood pressure and wave reflection in individuals with prehypertension: a pilot study.
BACKGROUND
Oral L-citrulline is efficiently converted to L-arginine, the precursor for endothelial nitric oxide (NO) synthesis. Oral L-arginine supplementation reduces brachial blood pressure (BP). We evaluated the effects of watermelon supplementation on aortic BP and arterial function in individuals with prehypertension.


METHODS
Heart rate (HR), brachial systolic BP (bSBP), brachial pulse pressure (bPP), aortic SBP (aSBP), aortic PP (aPP), augmentation index (AIx), AIx adjusted for HR of 75 beats/min (AIx@75), amplitude of the first (P1) and second (P2) systolic peaks, reflection time (Tr), and carotid-femoral pulse wave velocity (PWV) were evaluated in the supine position in nine subjects (four men/five women, age 54 ± 3 years) with prehypertension (134/77 ± 5/3 mm Hg). Subjects were randomly assigned to 6 weeks of watermelon supplementation (L-citrulline/L arginine, 2.7 g/1.3 g/day) or placebo followed by a 4-week washout period and then crossover.


RESULTS
There was a significant treatment effect (change in the value of watermelon minus placebo from baseline to 6 weeks) on bPP (-8 ± 3 mm Hg, P < 0.05), aSBP (-7 ± 2 mm Hg, P < 0.05), aPP (-6 ± 2 mm Hg, P < 0.01), AIx (-6 ± 3%, P < 0.05), AIx@75 (-4 ± 2%, P < 0.05), and P2 (-2 ± 1 mm Hg, P < 0.05). There was no significant treatment effect (P > 0.05) on bSBP, brachial diastolic BP (DBP), aortic DBP, Tr, P1, HR, and carotid-femoral PWV.


CONCLUSIONS
This pilot study shows that watermelon supplementation improves aortic hemodynamics through a decrease in the amplitude of the reflected wave in individuals with prehypertension.
Figueroa
Arturo
A
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, USA. afiguero@fsu.edu
Sanchez-Gonzalez
Marcos A
MA
Perkins-Veazie
Penelope M
PM
Arjmandi
Bahram H
BH
D001011:Aorta / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002339:Carotid Arteries / Q000503:physiopathology; D029773:Citrullus; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005263:Femoral Artery / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D058246:Prehypertension / Q000503:physiopathology*