Reproducibility of NIRS-derived mitochondrial oxidative capacity in highly active older adults.

Autor: Fennell CRJ; School of Sport and Exercise Sciences, University of Kent, Canterbury, Kent, England, UK. Electronic address: crjf3@kent.ac.uk., Mauger AR; School of Sport and Exercise Sciences, University of Kent, Canterbury, Kent, England, UK., Hopker JG; School of Sport and Exercise Sciences, University of Kent, Canterbury, Kent, England, UK.
Jazyk: angličtina
Zdroj: Experimental gerontology [Exp Gerontol] 2023 May; Vol. 175, pp. 112156. Date of Electronic Publication: 2023 Mar 28.
DOI: 10.1016/j.exger.2023.112156
Abstrakt: Introduction: In-vivo techniques using near-infrared spectroscopy (NIRS) have been developed to assess skeletal muscle mitochondrial oxidative capacity. However, the test-retest and day-to-day reliability of NIRS-derived mitochondrial oxidative capacity has yet to be established in older individuals. Therefore, the primary aim of this study was to determine the day-to-day and test-retest reliability of NIRS-derived mitochondrial oxidative capacity in older adults. The secondary aim was to examine the relationship between NIRS-derived mitochondrial capacity and whole-body aerobic fitness.
Material and Methods: Twenty-four healthy individuals (19 M, 5F; aged 60 ± 4 years; maximal oxygen uptake (V̇O 2peak ) = 41.2 ± 6.8 ml.kg -1 .min -1 ) completed three visits to the laboratory. Visit one assessed isometric maximal voluntary contractions of the knee extensors and aerobic capacity through an incremental exercise test. In visits two and three participants completed two measurements of NIRS-derived mitochondrial oxidative capacity in the vastus lateralis (VL).
Results: NIRS-derived mitochondrial oxidative capacity was found to have good to excellent day-to-day reliability (Day 1 vs Day 2; coefficient of variation (CV) = 7.0 %; standard error of measurement (SEM) = 5.2; intra-class correlation coefficient (ICC) = 0.94) and test re-test reliability (Day 1 [Test 1 vs Test 2]; CV = 5.0 %; SEM = 3.7; ICC 0.97 and Day 2 [Test 1 vs Test 2]; CV = 6.3 %; SEM = 4.9; ICC = 0.93). NIRS-derived mitochondrial oxidative capacity was found to be significantly correlated with V̇O 2peak (r = -0.61; R 2  = 0.37; P = 0.002), oxygen uptake at the gas exchange threshold (r = -0.49; R 2  = 0.24; P = 0.02), and oxygen uptake at the respiratory compensation point (r = -0.57; R 2  = 0.32; P = 0.004).
Conclusion: NIRS provides a reliable method for deriving a measure of VL mitochondrial oxidative capacity in highly active older adults and demonstrates a significant relationship with measures of whole-body aerobic fitness.
Competing Interests: Declaration of competing interest None.
(Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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