TY - JOUR T1 - Predictors of exercise-induced oxygen desaturation in systemic sclerosis patients with interstitial lung disease. JF - Respiratory Care DO - 10.4187/respcare.02452 SP - respcare.02452 AU - Fujiko Someya AU - Naoki Mugii AU - Minoru Hasegawa AU - Tetsutarou Yahata AU - Takao Nakagawa Y1 - 2013/06/12 UR - http://rc.rcjournal.com/content/early/2013/06/13/respcare.02452.abstract N2 - Background: The diffusion capacity of the lung for carbon monoxide (DLCO) is a good marker of disease severity in patients with idiopathic interstitial pneumonia, and is associated with oxygen saturation; however, little is known about this marker in systemic sclerosis patients with interstitial lung disease. We aimed to indicate the predicting factors among pulmonary functions in systemic sclerosis patients for exercise-induced oxygen desaturation. Methods: Data was collected prospectively from 80 of 110 consecutive systemic sclerosis patients with normal oxygen saturation at rest (> 95%) who could perform the six-minute walk test without physical discomfort including leg pain. Parameters from pulmonary function tests and echocardiography were collected for all subjects. Results: Thirty subjects showed a decline (≥ 4%) in oxygen saturation during the six-minute walk test (desaturation group). The other subjects were assigned to the normoxic group. The percent predicted of vital capacity, forced expiratory volume in one second, total lung capacity, DLCO, and DLCO/alveolar volume were lower and forced expiratory volume in one second/forced vital capacity was higher in the desaturation group than in the normoxic group. Logistic regression analysis showed the percent predicted of DLCO as a high accurate parameter for exercise-induced oxygen desaturation and the area under the ROC curve was 0.92 (cut-off point 56.3%, sensitivity 0.83, and specificity 0.86). Five subjects, over the cut-off point of the percent predicted of DLCO in the desaturation group, could not be distinguished from normoxic subjects using parameters including lung volumes and right ventricular systolic pressure. Conclusions: The factor underlying exercise-induced oxygen desaturation was suggested to be reduced percent predicted of DLCO, which was useful as a predictor in over 80% of subjects in this population. ER -