Dietary nitrate supplementation and exercise tolerance in patients with heart failure with reduced ejection fraction

• Main Author: Hirai, Daniel Müller [UNIFESP]
• Publication Date: 2017
• Other Authors: Zelt, Joel T., Jones, Joshua H., Castanhas, Luiza G., Bentley, Robert F., Earle, Wendy, Staples, Patti, Tschakovsky, Michael E., McCans, John, O'Donnell, Denis E., Neder, J. Alberto
• Format: Article
• Language: eng
• Source: Repositório Institucional da UNIFESP
• Download full: https://repositorio.unifesp.br/handle/11600/56378; http://dx.doi.org/10.1152/ajpregu.00263.2016
• topic: blood pressure; nitrite; nitric oxide; oxygen consumption; skeletal muscle

Endothelial dysfunction and reduced nitric oxide (NO) signaling are key abnormalities leading to skeletal muscle oxygen delivery-utilization mismatch and poor physical capacity in patients with heart failure with reduced ejection fraction (HFrEF). Oral inorganic nitrate supplementation provides an exogenous source of NO that may enhance locomotor muscle function and oxygenation with consequent improvement in exercise tolerance in HFrEF. Thirteen patients (left ventricular ejection fraction <= 40%) were enrolled in a double-blind, randomized crossover study to receive concentrated nitrate-rich (nitrate) or nitrate-depleted (placebo) beetroot juice for 9 days. Low- and high-intensity constant-load cardiopulmonary exercise tests were performed with noninvasive measurements of central hemodynamics (stroke volume, heart rate, and cardiac output via impedance cardiography), arterial blood pressure, pulmonary oxygen uptake, quadriceps muscle oxygenation (near-infrared spectroscopy), and blood lactate concentration. Ten patients completed the study with no adverse clinical effects. Nitrate-rich supplementation resulted in significantly higher plasma nitrite concentration compared with placebo (240 +/- 48 vs. 56 +/- 8 nM, respectively