Journal article
Acute inorganic nitrate supplementation and the hypoxic ventilatory response in patients with obstructive sleep apnea
Journal of applied physiology (1985), Vol.130(1), pp.87-95
01/01/2021
DOI: 10.1152/JAPPLPHYSIOL.00696.2020
PMCID: PMC7944935
PMID: 33211592
Abstract
Patients with obstructive sleep apnea (OSA) have increased cardiovascular disease risk largely attributable to hypertension. Heightened peripheral chemoreflex sensitivity (i.e., exaggerated responsiveness to hypoxia) facilitates hypertension in these patients. Nitric oxide blunts the peripheral chemoreflex, and patients with OSA have reduced nitric oxide bioavailability. We therefore investigated the dose-dependent effects of acute inorganic nitrate supplementation (beetroot juice), an exogenous nitric oxide source, on blood pressure and cardiopulmonary responses to hypoxia in patients with OSA using a randomized, double-blind, placebo-controlled crossover design. Fourteen patients with OSA (53 ± 10 yr, 29.2 ± 5.8 kg/m
, apnea-hypopnea index = 17.8 ± 8.1, 43%F) completed three visits. Resting brachial blood pressure and cardiopulmonary responses to inspiratory hypoxia were measured before, and 2 h after, acute inorganic nitrate supplementation [∼0.10 mmol (placebo), 4.03 mmol (low dose), and 8.06 mmol (high dose)]. Placebo increased neither plasma [nitrate] (30 ± 52 to 52 ± 23 μM,
= 0.26) nor [nitrite] (266 ± 153 to 277 ± 164 nM,
= 0.21); however, both increased following low (29 ± 17 to 175 ± 42 μM, 220 ± 137 to 514 ± 352 nM) and high doses (26 ± 11 to 292 ± 90 μM, 248 ± 155 to 738 ± 427 nM, respectively,
< 0.01 for all). Following placebo, systolic blood pressure increased (120 ± 9 to 128 ± 10 mmHg,
< 0.05), whereas no changes were observed following low (121 ± 11 to 123 ± 8 mmHg,
= 0.19) or high doses (124 ± 13 to 124 ± 9 mmHg,
= 0.96). The peak ventilatory response to hypoxia increased following placebo (3.1 ± 1.2 to 4.4 ± 2.6 L/min,
< 0.01) but not low (4.4 ± 2.4 to 5.4 ± 3.4 L/min,
= 0.11) or high doses (4.3 ± 2.3 to 4.8 ± 2.7 L/min,
= 0.42). Inorganic nitrate did not change the heart rate responses to hypoxia (beverage-by-time
= 0.64). Acute inorganic nitrate supplementation appears to blunt an early-morning rise in systolic blood pressure potentially through suppression of peripheral chemoreflex sensitivity in patients with OSA.
The present study is the first to examine the acute effects of inorganic nitrate supplementation on resting blood pressure and cardiopulmonary responses to hypoxia (e.g., peripheral chemoreflex sensitivity) in patients with obstructive sleep apnea (OSA). Our data indicate inorganic nitrate supplementation attenuates an early-morning rise in systolic blood pressure potentially attributable to blunted peripheral chemoreflex sensitivity. These data show proof-of-concept that inorganic nitrate supplementation could reduce the risk of cardiovascular disease in patients with OSA.
Details
- Title: Subtitle
- Acute inorganic nitrate supplementation and the hypoxic ventilatory response in patients with obstructive sleep apnea
- Creators
- Joshua M Bock - University of IowaBrady E Hanson - University of IowaThomas F Asama - University of IowaAndrew J Feider - University of IowaSatoshi Hanada - University of IowaAric W Aldrich - University of IowaMark Eric Dyken - University of IowaDarren P Casey - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.130(1), pp.87-95
- DOI
- 10.1152/JAPPLPHYSIOL.00696.2020
- PMID
- 33211592
- PMCID
- PMC7944935
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Grant note
- P30 CA086862 / NCI NIH HHS
- Language
- English
- Date published
- 01/01/2021
- Academic Unit
- Neurology; Anesthesia; Physical Therapy and Rehabilitation Science; Fraternal Order of Eagles Diabetes Research Center
- Record Identifier
- 9984294953402771
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