[Decrease of dynamic muscle function in patients with COPD: preliminary study].
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.


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.


CONCLUSIONS
Our results showed that skeletal muscle function parameters such as Pmax and Vopt could characterise peripheral muscle weakness of COPD.
Yquel
R
R
Service d'Exploration Fonctionnelle du Système Respiratoire, Hôpital Pellegrin-Tripode, Bordeaux, France. ronan.yquel@free.fr
Tessonneau
F
F
Pillet
O
O
Moinard
J
J
Manier
G
G
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000503:physiopathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*