Discriminación de la limitación al ejercicio en pacientes EPOC severa en pruebas máximas y submáximas

there are no data about symptoms of activity limitation in copd patients when maximal and submaximal exercise tests are compared. objective: to compare the activity limitation by dyspnea or fatigue between maximal and submaximal exercise tests. methods: moderate and severe copd patients were included (gold definition). they were classified as fatigue limited (fl) if borg scale of fatigue at maximal exercise was ≥ 2 points vs. dyspnea; and dyspnea limited (dl) if it was the reverse. each patient was evaluated in the same way with submaximal cycloergometry. results: 15 patients in the ld group and 18 patients in the lf group were evaluated. the lf patients were mainly women (fl 55.5 vs. dl 26.6% p: 0.034), had a low body-mass index (fl 24.1 ± 3.2 vs. dl 26.8 ± 2.1; p<0.04) and less airway obstruction (fl 47 ± 13.8% vs. dl 34.5 ± 11.1%, p<0.047). maximal and submaximal tests were concordant in fl patients (borg 2.8 ± 2; 2.5 ± 2.2, p=ns), but not in dl patients (borg 5.7 ± 2.1; 3.3 ± 1.6, p=0.014). conclusions: fl copd patients had less airway obstruction and body-mass index. in fl patients both tests were concordant. the submaximal exercise tests are specific but they have low sensitivity to determine the cause of symptom limitation.