One-minute sit-to-stand test to detect gas exchange capacity during exercise stress in patients with idiopathic or progressive pulmonary fibrosis: A randomized, crossover trial

Background: The 6-min walk test (6MWT), used to monitor disease progression or exacerbation in interstitial lung disease, faces challenges such as requiring a 30-m walking path and difficulty assessing patients with gait disturbance. The 1-min sit-to-stand test (1STST) offers a convenient alternative, potentially addressing these issues. Despite its advantages, the effectiveness of the 1STST in patients with idiopathic pulmonary fibrosis (IPF) and progressive pulmonary fibrosis (PPF) still needs to be explored. We assessed 1STST's ability to detect exercise-induced desaturation in a randomized, crossover trial involving patients with IPF or PPF. Methods: Participants were divided into group A (6MWT to 1STST) and B (1STST to 6MWT), with a 30-min rest period between the tests. The primary endpoint was the difference in nadir oxygen saturation (SpO2) between the groups throughout the study. Secondary endpoints included the percentage of participants with a nadir SpO2 <88% during the tests, a decline of >= 4% in SpO2, and the variation in Borg scores post-tests. Results: Twenty-three participants (91.3% male; mean age +/- standard deviation: 77.2 +/- 7.4 years) diagnosed with IPF and PPF were enrolled in this study. The difference in nadir SpO2 between the 1STST and 6MWT was 1.14% (95% confidence interval:-0.18, 2.48), with the 95% confidence intervals falling within the predefined equivalence range. No significant differences were observed in the secondary endpoints. Conclusions: The results suggest that the 1STST is as effective as the 6MWT in detecting desaturation in patients with IPF and PPF. Trial registration: This study was registered on the website of the Japan Registry of Clinical Trials (jRCT1032230037; URL: https://jrct.niph.go.jp/).