R Yquel1, F Tessonneau, O Pillet, J Moinard, G Manier. 1. Service d'Exploration Fonctionnelle du Système Respiratoire, Hôpital Pellegrin-Tripode, Bordeaux, France. ronan.yquel@free.fr
Abstract
BACKGROUND: The aim of the study was to investigate dynamic muscle function during all-out exercise in patients with chronic obstructive pulmonary disease (COPD) and to observe the relationship between body composition and skeletal muscle function. MATERIAL AND METHODS: Eight patients (FEV1: 53.0 +/- 9.3%) performed three tests i) three maximal sprints on a specialised cycle ergometer to assess individual Velocity-Power relationship, and measure of maximal anaerobic power (Pmax), optimal velocity (Vopt), ii) assessment of whole-body and subregional fat-free mass (FFM) by dual-energy X-ray absorptiometry, iii) determination of maximal oxygen consumption. RESULTS: Maximal anaerobic power and corresponding optimal velocity were 3.9 +/- 1.6 W x kg(-1) et 85.4 +/- 17.0 rpm, respectively. COPD showed a 30% decrease of Pmax, compared to healthy older subjects (5.6 +/- 1.1 W x kg(-1)). No such difference was observed with Vopt (85.4 +/- 13.0 rpm vs 86.8 +/- 9.5 rpm). Pmax and Vopt were highly significantly correlated with lower extremities FFM, but not with airflow obstruction parameters. CONCLUSION: Our results showed that skeletal muscle function parameters such as Pmax and Vopt could characterise peripheral muscle weakness of COPD.
BACKGROUND: The aim of the study was to investigate dynamic muscle function during all-out exercise in patients with chronic obstructive pulmonary disease (COPD) and to observe the relationship between body composition and skeletal muscle function. MATERIAL AND METHODS: Eight patients (FEV1: 53.0 +/- 9.3%) performed three tests i) three maximal sprints on a specialised cycle ergometer to assess individual Velocity-Power relationship, and measure of maximal anaerobic power (Pmax), optimal velocity (Vopt), ii) assessment of whole-body and subregional fat-free mass (FFM) by dual-energy X-ray absorptiometry, iii) determination of maximal oxygen consumption. RESULTS: Maximal anaerobic power and corresponding optimal velocity were 3.9 +/- 1.6 W x kg(-1) et 85.4 +/- 17.0 rpm, respectively. COPD showed a 30% decrease of Pmax, compared to healthy older subjects (5.6 +/- 1.1 W x kg(-1)). No such difference was observed with Vopt (85.4 +/- 13.0 rpm vs 86.8 +/- 9.5 rpm). Pmax and Vopt were highly significantly correlated with lower extremities FFM, but not with airflow obstruction parameters. CONCLUSION: Our results showed that skeletal muscle function parameters such as Pmax and Vopt could characterise peripheral muscle weakness of COPD.