Comparison between six minutes walking test and sit-to-stand test in COPD patients

Abstract

Background: COPD is frequently associated to a reduced exercise tolerance. This parameter is routinely evaluated using six minute walking test (6MWT). New field tests appear and are investigated regularly as alternative tests. The aim of this study was to compare 6MWT to sit-to-stand test (STST) in COPD patients. Method: 19 COPD patients were recruited and performed randomly two tests: 6MWT and STST. A training test was performed systematically before. Six minutes walking distance (6MWD) and number of repetitions were measured. Cardiorespiratory parameters, dyspnea and lower limb fatigue (Borg) were recorded before and after the tests. Results: 6MWD (445 ± 105m) and sit-to-stand repetitions (21 ± 7) were correlated (r = 0.789; p < 0.001). At variance with 6MWT, no training was necessary before STST. Variations of heart rate and pulsed oxygen saturation were significantly different between tests (23 ± 17% vs 13 ± 11%; p = 0.022 and -7.6 ± 4.6% vs -0.7 ± 2.7%; p < 0.001 for 6MWT and STST respectively). Variations of dyspnea and lower limb fatigue were similar between both tests (p = 0.827 and p = 0.467). Conclusion: The sit-to-stand test can be an alternative to the 6MWT to estimate exercise capacity in COPD patients. The variation of dypsnea is similar between both tests.