Mathieu Marillier 1,2 , Anne-Catherine Bernard 1,2 , Samuel Verges 2 , Onofre Moran-Mendoza 1 , Denis E O'Donnell 1 , José Alberto Neder 3 Show Affiliations »
Abstract
BACKGROUND: Exercise-induced hypoxaemia is a hallmark of chronic fibrotic interstitial lung disease (f-ILD). It remains unclear whether patients' severe hypoxaemia may exaggerate locomotor muscle fatigue and, if so, to what extent oxygen (O2) supplementation can ameliorate these abnormalities. METHODS: Fifteen patients (12 males, 9 with idiopathic pulmonary fibrosis) performed a constant-load (60% peak work rate) cycle test to symptom limitation (Tlim) while breathing medical air. Fifteen age-matched and sex-matched controls cycled up to patients' Tlim. Patients repeated the exercise test on supplemental O2 (42%±7%) for the same duration. Near-infrared spectroscopy assessed vastus lateralis oxyhaemoglobin concentration ((HbO2)). Pre-exercise to postexercise variation in twitch force (∆Tw) induced by femoral nerve magnetic stimulation quantified muscle fatigue. RESULTS: Patients showed severe hypoxaemia (lowest O2 saturation by pulse oximetry=80.0%±7.6%) which was associated with a blunted increase in muscle (HbO2) during exercise vs controls (+1.3±0.3 µmol vs +4.4±0.4 µmol, respectively; p<0.001). Despite exercising at work rates ∼ one-third lower than controls (42±13 W vs 66±13 W), ∆Tw was greater in patients (∆Tw/external work performed by the leg muscles=-0.59±0.21 %/kJ vs -0.25±0.19 %/kJ; p<0.001). Reversal of exertional hypoxaemia with supplemental O2 was associated with a significant increase in muscle (HbO2), leading to a reduced decrease in ∆Tw in patients (-0.33±0.19 %/kJ; p<0.001 vs air). Supplemental O2 significantly improved leg discomfort (p=0.005). CONCLUSION: O2 supplementation during exercise improves leg muscle oxygenation and fatigue in f-ILD. Lessening peripheral muscle fatigue to enhance exercise tolerance is a neglected therapeutic target that deserves clinical attention in this patient population. © Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.
BACKGROUND: Exercise-induced hypoxaemia is a hallmark of chronic fibrotic interstitial lung disease (f-ILD). It remains unclear whether patients ' severe hypoxaemia may exaggerate locomotor muscle fatigue and, if so, to what extent oxygen (O2 ) supplementation can ameliorate these abnormalities. METHODS: Fifteen patients (12 males, 9 with idiopathic pulmonary fibrosis ) performed a constant-load (60% peak work rate) cycle test to symptom limitation (Tlim) while breathing medical air. Fifteen age-matched and sex-matched controls cycled up to patients ' Tlim. Patients repeated the exercise test on supplemental O2 (42%±7%) for the same duration. Near-infrared spectroscopy assessed vastus lateralis oxyhaemoglobin concentration ((HbO2)). Pre-exercise to postexercise variation in twitch force (∆Tw) induced by femoral nerve magnetic stimulation quantified muscle fatigue . RESULTS: Patients showed severe hypoxaemia (lowest O2 saturation by pulse oximetry=80.0%±7.6%) which was associated with a blunted increase in muscle (HbO2) during exercise vs controls (+1.3±0.3 µmol vs +4.4±0.4 µmol, respectively; p<0.001). Despite exercising at work rates ∼ one-third lower than controls (42±13 W vs 66±13 W), ∆Tw was greater in patients (∆Tw/external work performed by the leg muscles=-0.59±0.21 %/kJ vs -0.25±0.19 %/kJ; p<0.001). Reversal of exertional hypoxaemia with supplemental O2 was associated with a significant increase in muscle (HbO2), leading to a reduced decrease in ∆Tw in patients (-0.33±0.19 %/kJ; p<0.001 vs air). Supplemental O2 significantly improved leg discomfort (p=0.005). CONCLUSION: O2 supplementation during exercise improves leg muscle oxygenation and fatigue in f-ILD. Lessening peripheral muscle fatigue to enhance exercise tolerance is a neglected therapeutic target that deserves clinical attention in this patient population. © Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.
Entities: Chemical
Disease
Species
Keywords:
Long Term Oxygen Therapy (LTOT); exercise; interstitial fibrosis; lung physiology; pulmonary rehabilitation; respiratory measurement; short burst oxygen therapy
Mesh： See more »
Year: 2021
PMID： 33542089 DOI： 10.1136/thoraxjnl-2020-215135
Source DB: PubMed Journal: Thorax ISSN： 0040-6376 Impact factor: 9.139