RT Journal Article SR Electronic T1 Prevalence, predictors and impact of nocturnal hypoxemia in non-apnoeic patients with COPD JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA4591 DO 10.1183/13993003.congress-2015.PA4591 VO 46 IS suppl 59 A1 Pawan Gupta A1 Sunil Chhabra YR 2015 UL http://erj.ersjournals.com/content/46/suppl_59/PA4591.abstract AB Background: Prevalence of significant nocturnal desaturation(NOD) in non-apnoeic patients with Chronic Obstructive Pulmonary Disease (COPD)varies widely from 27 to70% with limited information on its predictors and impacts.Aims: To determine the prevalence and predictors of NOD in non-apnoeic COPD and evaluate its impacts.Methods: Sixty patients with COPD with daytime oxygen saturation (SaO2) > 90% were categorized as “desaturators” and “non-desaturators” after overnight pulse oximetry, with desaturation defined as SaO2 < 90% occurring for > 30% of total recording time with a nadir< 85%. Investigations included a 6-minute walk test, lung function study, high resolution computed tomography (HRCT Chest), and measurement of Pittsburgh Sleep Quality Index and health-related quality of life. Sleep apnoea was ruled out using Epworth Sleepiness Score and Apnea-Hypopnea Index (AHI) on sleep screening.Results: The prevalence of NOD was 25%. These patients had greater dyspnea, higher GOLD severity, lower FEV1 and diffusion capacity, higher BODE index, greater frequency of exercise desaturation,and a poorer quality of sleep and health-related quality of life but were similar to non-desaturators for age, gender distribution, AHI and frequency of emphysema on HRCT. Multiple regression analysis identified exercise desaturation and lower daytime PaO2 as significant predictors of NOD.Conclusions: NOD is common in non-apnoeic COPD, is associated with disease severity and adversely impacts sleep quality and health-related quality of life. Exercise desaturation and low daytime PaO2 predict its occurrence.