| Autor: |
Jacob Peter Hartmann, Rasmus H. Dahl, Stine Nymand, Gregers W. Munch, Camilla K. Ryrsø, Bente K. Pedersen, Pia Thaning, Stefan P. Mortensen, Ronan M. G. Berg, Ulrik Winning Iepsen |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
Frontiers in Physiology, Vol 13 (2022) |
| Druh dokumentu: |
article |
| ISSN: |
1664-042X |
| DOI: |
10.3389/fphys.2022.979359 |
| Popis: |
Aim: Skeletal muscle convective and diffusive oxygen (O2) transport are peripheral determinants of exercise capacity in both patients with chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). We hypothesised that differences in these peripheral determinants of performance between COPD and CHF patients are revealed during small muscle mass exercise, where the cardiorespiratory limitations to exercise are diminished.Methods: Eight patients with moderate to severe COPD, eight patients with CHF (NYHA II), and eight age- and sex-matched controls were studied. We measured leg blood flow (Q̇leg) by Doppler ultrasound during submaximal one-legged knee-extensor exercise (KEE), while sampling arterio-venous variables across the leg. The capillary oxyhaemoglobin dissociation curve was reconstructed from paired femoral arterial-venous oxygen tensions and saturations, which enabled the estimation of O2 parameters at the microvascular level within skeletal muscle, so that skeletal muscle oxygen conductance (DSMO2) could be calculated and adjusted for flow (DSMO2/Q̇leg) to distinguish convective from diffusive oxygen transport.Results: During KEE, Q̇leg increased to a similar extent in CHF (2.0 (0.4) L/min) and controls (2.3 (0.3) L/min), but less in COPD patients (1.8 (0.3) L/min) (p |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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