title: Correlation between mild hypoxaemia and limb skeletal muscle function in chronic obstructive pulmonary disease - pilot study.
abstract: BACKGROUND
  Exercise capacity in COPD patients depends on the degree of airflow obstruction, the severity of the hypoxaemia and skeletal muscle function. Muscle atrophy and weakness are considered systemic consequences of COPD and are associated with reduced exercise capacity.
  
  
  OBJECTIVE
  To investigate the correlation between mild hypoxaemia and muscular strength, muscular fatigue and functional capacity in COPD patients.
  
  
  METHODS
  Ten patients enrolled on a PRP at the Hospital Universitário de Brasília - HUB were included in this study. Lung function was evaluated by spirometry and arterial blood gas analysis. Functional evaluation was made using the 6MWT and using isometric contraction of deltoid and quadriceps muscles.
  
  
  RESULTS
  There were positive correlations between PaO2, quadriceps strength (r2 = 0.61 and p = 0.007) and PaO2 and the 6MWT (r2 = 0.96, p = 0.001). There were negative correlations between PaO2 and median frequency of quadriceps (r2 = -0.42 and p = 0.04). We observed significant correlation between quadriceps strength and the 6MWT (r2 = 0.67 and p = 0.001). There was negative correlation between median frequency of quadriceps and the 6MWT (r2 = -0.42 and p = 0.04). We did not observe any correlation between PaO2 and strength or median frequency of deltoid muscle.
  
  
  CONCLUSIONS
  PaO2 has important correlations with muscular function variables. The main negative impact of mild hypoxaemia and precocious limb muscular disability on COPD patients is decreased functional capacity.
authors.affiliation: Health Sciences, Universidade de Brasília, Brasil.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Leite Rodrigues
authors.forename: César Augusto
authors.initials: CA
authors.lastname: Melo e Silva
authors.forename: César
authors.initials: C
authors.lastname: Ferreira Amorim
authors.forename: Terezinha
authors.initials: T
authors.lastname: Lima
authors.forename: Fernanda
authors.initials: F
authors.lastname: Almeida Ribeiro
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Assis Viegas
mesh_terms: D015510:Clinical Medicine