Detection of impaired gas exchange using the 1-minute sit-to-stand test in patients with interstitial lung disease

Although pulmonary function tests (PFTs) are important in patients with interstitial lung disease (ILD), they cannot be easily performed in a primary healthcare setting. This study aimed to examine the usefulness of the difference between pulse oxygen saturation (SpO2) at rest and the lowest SpO2 during the 1-min sit-to-stand test (delta SpO2-1STST) for predicting pulmonary function impairment. We retrospectively reviewed 116 patients with ILD who underwent 1STST and PFTs. The delta SpO2-1STST and diffusing capacity for carbon monoxide (DLco) strongly correlated (ρ = 0.70). The delta SpO2-1STST was effective in predicting impaired gas exchange (cut-off value, −4%; AUC, 0.86; sensitivity, 74%; specificity, 87%). The Delta SpO2-1STST may be a reasonable tool for predicting abnormalities in PFTs.