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Effects of dietary nitrate supplementation on the response to extremity cooling and endothelial function in individuals with cold sensitivity. A double blind, placebo controlled, crossover, randomised control trial

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posted on 22.09.2017, 12:41 by Clare Eglin, Joseph T. Costello, Stephen Bailey, Mark Gilchrist, Heather Massey, Anthony I. Shepherd
Individuals with cold sensitivity have low peripheral skin blood flow and skin temperature possibly due to reduced nitric oxide (NO•) bioavailability. Beetroot has a high concentration of inorganic nitrate and may increase NO-mediated vasodilation. Using a placebo-controlled, double blind, randomised, crossover design, this study tested the hypotheses that acute beetroot supplementation would increase the rate of cutaneous rewarming following a local cold challenge and augment endothelium-dependent vasodilation in cold sensitive individuals. Thirteen cold sensitive participants completed foot and hand cooling (separately, in 15 °C water for 2 minutes) with spontaneous rewarming in 30°C air whilst skin temperature and cutaneous vascular conductance (CVC) were measured (Baseline). On two further separate visits, participants consumed 140 ml of either concentrated beetroot juice (nitrate supplementation) or nitrate-depleted beetroot juice (Placebo) 90 minutes before resting seated blood pressure was measured. Endothelial function was assessed by measuring CVC at the forearm, finger and foot during iontophoresis of 1% w/v acetylcholine followed by foot and hand cooling as for Baseline. Plasma nitrite concentrations significantly increased in nitrate supplementation compared to Placebo and Baseline (502 ± 246 nmol.L-1; 73 ± 45 nmol.L-1; 74 ± 49 nmol.L-1 respectively; n=11; P < 0.001). Resting blood pressure and the response to foot and hand cooling did not differ between conditions (all P > 0.05). Nitrate supplementation did not alter endothelial function in the forearm, finger or foot (all P > 0.05) compared to Placebo. Despite a physiologically meaningful rise in plasma nitrite concentrations, acute nitrate supplementation does not alter extremity rewarming, endothelial function or blood pressure in individuals with cold sensitivity.

History

School

  • Sport, Exercise and Health Sciences

Published in

Nitric Oxide: Biology and Chemistry

Volume

70

Pages

76-85

Citation

EGLIN, C. ...et al., 2017. Effects of dietary nitrate supplementation on the response to extremity cooling and endothelial function in individuals with cold sensitivity. A double blind, placebo controlled, crossover, randomised control trial. Nitric Oxide, 70, pp. 76-85.

Publisher

© Elsevier

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

18/09/2017

Publication date

2017-09-20

Notes

This paper was published in the journal Nitric Oxide and the definitive published version is available at https://doi.org/10.1016/j.niox.2017.09.005.

ISSN

1089-8611

Language

en

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Keywords

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