Chronic bronchitis leads to accelerated hyperinflation in COPD patients during exercise.
Respirology
; 20(4): 618-25, 2015 May.
Article
em En
| MEDLINE
| ID: mdl-25799924
ABSTRACT
BACKGROUND AND OBJECTIVE:
It is not known whether patients with chronic obstructive pulmonary disease (COPD) have a different exercise capacity with (CB(+) ) or without accompanying chronic bronchitis (CB(-) ).METHODS:
We conducted spirometry, a 6-min walk distance test and cardiopulmonary exercise test in 50 age-matched healthy control subjects, 45 COPD patients without CB (CB(-) ) and 37 COPD patients with CB (CB(+) ). A multiple regression model was established to identify factors independently associated with peak oxygen consumption ( V Ë O 2 ).RESULTS:
Patients with and without CB had similar forced expiratory volume in 1 s (FEV1 ). CB(+) patients had a lower V Ë O 2 . CB(+) and CB(-) participants had similar increases in tidal volume at peak exercise; however, CB(+) patients had an increased respiratory rate (RR). These patients reached the peak value for ratio of end-expiratory lung volume to total lung capacity (TLC) at a lower work load. A stepwise multiple linear regression analysis identified chronic bronchitis, FEV1 , diffusing capacity for carbon monoxide, the ratio of residual volume to TLC and serum tumour necrosis factor-α as independent predictors of peak V Ë O 2 .CONCLUSIONS:
CB significantly lowers exercise capacity in COPD patients because of dynamic hyperinflation during exercise. The accelerated dynamic hyperinflation may contribute to increased airway and systemic inflammation in COPD patients.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Enfisema Pulmonar
/
Tolerância ao Exercício
/
Bronquite Crônica
/
Doença Pulmonar Obstrutiva Crônica
Tipo de estudo:
Prognostic_studies
Limite:
Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article