Dietary nitrate supplementation enhances exercise performance in peripheral arterial disease
| Autor: | Mitch VanBruggen, Jennifer L. Robbins, Thomas Stabler, William E. Kraus, Jason D. Allen, Johanna L. Johnson, Aarti A. Kenjale, Eunji Yim, Grayson Privette, Katherine L. Ham |
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| Rok vydání: | 2011 |
| Předmět: |
Male
Time Factors Physiology Arbitrary unit Blood Pressure Walking Plant Roots Hemoglobins Heart Rate Aged 80 and over Cross-Over Studies Exercise Tolerance Spectroscopy Near-Infrared Articles Middle Aged Vasodilation Treatment Outcome Female Beta vulgaris medicine.symptom Perfusion Blood drawing medicine.medical_specialty Nitric Oxide Beverages Peripheral Arterial Disease Oxygen Consumption Physiology (medical) Internal medicine Heart rate North Carolina medicine Humans Ankle Brachial Index Muscle Skeletal Nitrites Aged Analysis of Variance Nitrates business.industry Oxygenation Intermittent Claudication Intermittent claudication Surgery Endocrinology Blood pressure Oxyhemoglobins Dietary Supplements Exercise Test business Claudication |
| Zdroj: | Journal of Applied Physiology. 110:1582-1591 |
| ISSN: | 1522-1601 8750-7587 |
| Popis: | Peripheral arterial disease (PAD) results in a failure to adequately supply blood and oxygen (O2) to working tissues and presents as claudication pain during walking. Nitric oxide (NO) bioavailability is essential for vascular health and function. Plasma nitrite (NO2−) is a marker of vascular NO production but may also be a protected circulating “source” that can be converted to NO during hypoxic conditions, possibly aiding perfusion. We hypothesized that dietary supplementation of inorganic nitrate in the form of beetroot (BR) juice would increase plasma NO2−concentration, increase exercise tolerance, and decrease gastrocnemius fractional O2extraction, compared with placebo (PL). This was a randomized, open-label, crossover study. At each visit, subjects ( n = 8) underwent resting blood draws, followed by consumption of 500 ml BR or PL and subsequent blood draws prior to, during, and following a maximal cardiopulmonary exercise (CPX) test. Gastrocnemius oxygenation during the CPX was measured by near-infrared spectroscopy. There were no changes from rest for [NO2−] (152 ± 72 nM) following PL. BR increased plasma [NO2−] after 3 h (943 ± 826 nM; P ≤ 0.01). Subjects walked 18% longer before the onset of claudication pain (183 ± 84 s vs. 215 ± 99 s; P ≤ 0.01) and had a 17% longer peak walking time (467 ± 223 s vs. 533 ± 233 s; P ≤ 0.05) following BR vs. PL. Gastrocnemius tissue fractional O2extraction was lower during exercise following BR (7.3 ± 6.2 vs. 10.4 ± 6.1 arbitrary units; P ≤ 0.01). Diastolic blood pressure was lower in the BR group at rest and during CPX testing ( P ≤ 0.05). These findings support the hypothesis that NO2−-related NO signaling increases peripheral tissue oxygenation in areas of hypoxia and increases exercise tolerance in PAD. |
| Databáze: | OpenAIRE |
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