Nocturnal desaturation predicts mortality in immune-mediated ILDs

Introduction: Nocturnal desaturation may contribute to long-term pulmonary vascular stress in interstitial lung disease (ILD). We studied the prevalence and prognostic utility of nocturnal desaturation across ILDs. Methods: ILD patients with overnight oximetry (January 2010-December 2013) were included (n=437; Idiopathic Pulmonary Fibrosis, n=122; Connective Tissue Disease-ILD, n=48; Hypersensitivity Pneumonitis, n=60; Non-specific Interstitial Pneumonia, n=56; unclassifiable, n=27; Sarcoidosis, n=66; other, n=58). Desaturation index (DI) was defined as the number of desaturation events >4%/hr. Results: DI was higher in NSIP and CTD-ILD than in IPF (p=0.03 and p=0.02 respectively). In the whole cohort, DLco and serum BNP predicted mortality (HR 0.95; 95% CI 0.94, 0.96; p Conclusion: DI is more prevalent and it is a stronger predictor of mortality in immune-mediated ILDs than in IPF and may be an important manifestation of these disorders.