[Determining factors of walking distance during 6-minutes walk test in COPD patients].

Introduction: In stable COPD, we studied the factors determining six-minute walking distance and dyspnea at the end of the test.

Methods: Patients were evaluated by tests of lung function, St Georges' respiratory questionnaire (SGRQ) and 6MWT with inspiratory capacity measurements (IC) and continuous oxymetry.

Results: Eighty-two patients (mean FEV(1): 56+19% predicted) were studied. Mean 6-minute walking distance was 477+89m, (72+14% PV). Walking distance during 6MWT (m) was correlated with FEV(1), IC/TLC ratio, TLC, pre-test IC and DLco/VA. When expressed as a percent of predicted values, walking distance was correlated with FRC, pre-test IC and SGRQ activity score. End-test dyspnea was correlated with FRC, pre-test dyspnea and SGRQ activity and total scores.

Conclusion: The factors determining 6-minute walking distance and end-test dyspnea are complex and include both functional and non-functional factors. In COPD, 6MWT is thus an investigation that has additional integrative value.