The influence of lung function and muscular strength on the functional capacity of chronic obstructive pulmonary disease patients.
OBJECTIVE
To determine which variable (forced expiratory volume in 1 second (FEV1), partial pressure of oxygen in arterial blood (PaO2), nocturnal hypoxaemia and muscular strength of femoral quadriceps) can predict the distance walked in the six-minute walk test (6MWT) by COPD patients.


METHODS
A cross-sectional and observational study of thirty patients referred to a pulmonary rehabilitation programme at a university hospital. Lung function was evaluated by spirometry, arterial blood gas analysis and nocturnal oximetry. Muscle function was evaluated by quadriceps strength and functional capacity by the 6MWT.


RESULTS
Bivariate regression analysis showed that quadriceps strength, was the only variable to correlate significantly with the distance walked in the 6MWT (p=0.002), accounting for 38% of the 6MWT variance. The statistical relationship established for these variables was 1kg of quadriceps strength equalled 5.9 metres walked in the 6MWT.


CONCLUSIONS
Our results showed the importance of lower limb muscle strength in submaximal exercise testing. We conclude that femoral quadriceps muscle strength is the only one of the variables studied which can predict the distance COPD patients walk in the 6MWT.
Leite Rodrigues
Sérgio
S
Mestre em Ciências da Saúde / MSC, Health Sciences.
Melo E Silva
César Augusto
CA
Lima
Tereza
T
de Assis Viegas
Carlos Alberto
CA
Palmeira Rodrigues
Marcelo
M
Almeida Ribeiro
Fernanda
F
D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D000860:Hypoxia / Q000209:etiology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D010100:Oxygen / Q000097:blood; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000150:complications / Q000503:physiopathology*
D010100:Oxygen