Dietary nitrate improves muscle microvascular reactivity and lowers blood pressure at rest and during isometric exercise in untreated hypertensives.
Title | Dietary nitrate improves muscle microvascular reactivity and lowers blood pressure at rest and during isometric exercise in untreated hypertensives. |
Publication Type | Journal Article |
Year of Publication | 2019 |
Authors | Zafeiridis, A., Triantafyllou A., Papadopoulos S., Koletsos N., Touplikioti P., Zafeiridis A. S., Gkaliagkousi E., Dipla K., & Douma S. |
Journal | Microcirculation |
Volume | 26 |
Issue | 3 |
Pagination | e12525 |
Date Published | 2019 04 |
ISSN | 1549-8719 |
Keywords | Adult, Blood Pressure, Dietary Supplements, Double-Blind Method, Exercise, Female, Hand Strength, Hemodynamics, Humans, Hypertension, Male, Middle Aged, Nitrates, Pulse Wave Analysis, Vascular Resistance, Vascular Stiffness |
Abstract | OBJECTIVE: This double-blind, cross-over study examined in drug-naïve hypertensives the effects of a single dose of dietary nitrate (beetroot juice, BRJ) on (a) office/ambulatory BP and arterial stiffness, (b) muscle microvascular function, and (c) hemodynamic responses and cardiovagal baroreceptor sensitivity (cBRS) at rest and during isometric exercise.METHODS: Eighteen untreated hypertensives (44.0 ± 2.6 years) consumed randomly, a nitrate-rich (8.1 mmol-BRJ ) and a nitrate-depleted (BRJ ) BRJ. Office BP and pulse wave velocity were assessed before/after BRJ. An occlusion-reperfusion maneuver with continuous monitoring of muscle oxygenated hemoglobin (O Hb) and total hemoglobin (tHb), via NIRS, followed. Participants performed submaximal isometric handgrip with beat-by-beat monitoring of hemodynamics and cBRS. Ambulatory BP assessment followed.RESULTS: During reperfusion, following arterial occlusion, the magnitude and rate of muscle microvascular reoxygenation (O Hb) and red blood cell content (tHb) were higher in BRJ vs BRJ (P < 0.05), suggesting improved microvascular reactivity. Office/ambulatory BP were lower following BRJ vs BRJ (P < 0.05); pulse-wave-velocity was not altered. During isometric handgrip, BP and peripheral resistance rise were smaller in BRJ vs BRJ (P < 0.01-0.05), with no differences in cBRS.CONCLUSIONS: In drug-naïve hypertensives, a single dose of BRJ induces (a) short-term reductions in resting/ambulatory BP, (b) acute improvements in muscle microvascular function, and (c) attenuation in BP and peripheral resistance responses during isometric exercise. |
DOI | 10.1111/micc.12525 |
Alternate Journal | Microcirculation |
PubMed ID | 30586209 |