INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is associated with metabolic abnormalities in muscles of the lower limbs, but it is not known whether these abnormalities are generalized or limited to specific muscle groups, nor is there an easy way of predicting their presence. METHODS: Metabolism in the quadriceps and biceps of 14 COPD patients and controls was assessed during sustained contraction using 31-phosphorus magnetic resonance spectroscopy ((31) P MRS). T1 MRI was used to measure quadriceps intermuscular adipose tissue (IMAT). RESULTS: COPD patients had prolonged quadriceps phosphocreatine time (patients: 38.8 ± 12.7 s; controls: 25.2 ± 10.6 s; P = 0.006) and a lower pH (patents: 6.88 ± 0.1; controls: 6.99 ± 0.06; P = 0.002). Biceps measures were not significantly different. IMAT was associated with a nadir pH <7.0 (area under the curve = 0.84). CONCLUSIONS: Anaerobic metabolism during contraction was characteristic of quadriceps, but not biceps, muscles of patients with COPD and was associated with increased IMAT. Because IMAT can be assessed quickly by conventional MRI, it may be a useful approach for identifying patients with abnormal muscle bioenergetics.
INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is associated with metabolic abnormalities in muscles of the lower limbs, but it is not known whether these abnormalities are generalized or limited to specific muscle groups, nor is there an easy way of predicting their presence. METHODS: Metabolism in the quadriceps and biceps of 14 COPD patients and controls was assessed during sustained contraction using 31-phosphorus magnetic resonance spectroscopy ((31) P MRS). T1 MRI was used to measure quadriceps intermuscular adipose tissue (IMAT). RESULTS: COPD patients had prolonged quadriceps phosphocreatine time (patients: 38.8 ± 12.7 s; controls: 25.2 ± 10.6 s; P = 0.006) and a lower pH (patents: 6.88 ± 0.1; controls: 6.99 ± 0.06; P = 0.002). Biceps measures were not significantly different. IMAT was associated with a nadir pH <7.0 (area under the curve = 0.84). CONCLUSIONS: Anaerobic metabolism during contraction was characteristic of quadriceps, but not biceps, muscles of patients with COPD and was associated with increased IMAT. Because IMAT can be assessed quickly by conventional MRI, it may be a useful approach for identifying patients with abnormal muscle bioenergetics.
Authors: Michael I Polkey; Jens Praestgaard; Amy Berwick; Frits M E Franssen; Dave Singh; Michael C Steiner; Richard Casaburi; Hanns-Christian Tillmann; Estelle Lach-Trifilieff; Ronenn Roubenoff; Daniel S Rooks Journal: Am J Respir Crit Care Med Date: 2019-02-01 Impact factor: 21.405
Authors: Gwenael Layec; Corey R Hart; Joel D Trinity; Oh-Sung Kwon; Matthew J Rossman; Ryan M Broxterman; Yann Le Fur; Eun-Kee Jeong; Russell S Richardson Journal: Am J Physiol Endocrinol Metab Date: 2017-03-14 Impact factor: 4.310
Authors: Raolat M Abdulai; Tina Jellesmark Jensen; Naimish R Patel; Michael I Polkey; Paul Jansson; Bartolomé R Celli; Stephen I Rennard Journal: Am J Respir Crit Care Med Date: 2018-02-15 Impact factor: 21.405
Authors: Katrina J Curtis; Katie A O'Brien; Rebecca J Tanner; Juliet I Polkey; Magdalena Minnion; Martin Feelisch; Michael I Polkey; Lindsay M Edwards; Nicholas S Hopkinson Journal: PLoS One Date: 2015-12-23 Impact factor: 3.240
Authors: Riemer J K Vegter; Sebastiaan van den Brink; Leonora J Mouton; Anita Sibeijn-Kuiper; Lucas H V van der Woude; Jeroen A L Jeneson Journal: Front Physiol Date: 2021-02-19 Impact factor: 4.566
Authors: Matthew Maddocks; Dinesh Shrikrishna; Simone Vitoriano; Samantha A Natanek; Rebecca J Tanner; Nicholas Hart; Paul R Kemp; John Moxham; Michael I Polkey; Nicholas S Hopkinson Journal: Eur Respir J Date: 2014-07-03 Impact factor: 16.671