Predictors of Exercise-Induced Oxygen Desaturation in Systemic Sclerosis Patients With Interstitial Lung Disease

Abstract

BACKGROUND:The diffusion capacity of the lung for carbon monoxide (D LCO ) is a good marker of disease severity in patients with idiopathic interstitial pneumonia, and is associated with oxygen saturation; however, little is known about D LCO in systemic sclerosis patients with interstitial lung disease. We studied potential predictors of exercise-induced oxygen desaturation in patients with systemic sclerosis. METHODS: Data were collected prospectively from 80 of 110 consecutive systemic sclerosis patients with normal oxygen saturation (> 95%) at rest, who could perform the 6-min walk test without physical discomfort, including leg pain. Pulmonary function tests and echocardiography were collected from all subjects. RESULTS: Thirty subjects showed a > 4% decline in oxygen saturation during the 6-min walk test (desaturation group). The other subjects were assigned to the normoxic group. The percent-of-predicted values for FVC, FEV 1 , total lung capacity, D LCO , and D LCO /alveolar volume were lower, and FEV 1 /FVC was higher, in the desaturation group. Logistic regression analysis showed the percent-of-predicted D LCO as a highly accurate predictor of exercise-induced oxygen desaturation: the area under the receiver operating characteristic curve was 0.92 (cutoff point 56.3%, sensitivity 0.83, specificity 0.86). Five subjects over the cutoff point of the percent-of-predicted D LCO in the desaturation group could not be distinguished from the normoxic subjects with the lung-volume measurements or right-ventricular systolic pressure. CONCLUSIONS: The factor underlying exercise-induced oxygen desaturation appeared to be reduced percent-of-predicted D LCO , which was useful as a predictor in over 80% of the subjects.

Aerobic and resistance exercise in systemic sclerosis: State of the art

“…reduced predicted lung volumes seem to predict oxygen desaturation in exercise testing (Someya et al, 2014). PAH and exercise-induced PAH are common features in SSc (Gargani et al, 2013;Saggar et al, 2010;Suzuki et al, 2015;Voilliot et al, 2014).…”

“…Exercise‐induced oxygen desaturation may occur in patients with SSc and ILD (Someya, Mugii, Hasegawa, Yahata, & Nakagawa, ). Reduced diffusion lung capacity for carbon monoxide (DLCO) and reduced predicted lung volumes seem to predict oxygen desaturation in exercise testing (Someya et al, ). PAH and exercise‐induced PAH are common features in SSc (Gargani et al, ; Saggar et al, ; Suzuki et al, ; Voilliot et al, ).…”

Clinical significance and usefulness of rehabilitation for systemic sclerosis

“…A decrease in SpO 2 to ≤88% during 6MWT predicts a high-mortality risk in patients with IPF (37). A factor underlying exercise-induced oxygen desaturation may be reduced as %DLco, which was found to be useful as a predictor in more than 80% of subjects (22).…”

Effects of walking with a portable oxygen concentrator on muscle oxygenation while performing normal or pursed-lip breathing in patients with interstitial lung disease: a randomized crossover trial

“… 13 Peripheral muscle dysfunction is an essential contributor to reduced exercise capacity in ILD patients, and the resulting reduction in activity leads to a vicious cycle that exacerbates exercise capacity and dyspnea. 14 – 16 In addition, it has been reported that oxygen supplementation in IPF patients improves cerebral and muscle oxygenation and alleviates dyspnea. 17 From this perspective, we considered oxygenation of the quadriceps, which is the most important muscle for walking, as the primary outcome.…”