P007 A Comparison of Sleep Study Parameters between COPD+OSA (Overlap Syndrome) and Obstructive Sleep Apnoea

Abstract Background Comorbid Chronic Obstructive Pulmonary Disease (COPD) and Obstructive Sleep Apnoea (OSA)—Overlap Syndrome (OVS) is associated with worse sleep study parameters than OSA alone. The patient demographics and severity of OSA often confound these sleep study parameters. Aim: In this study, we aim to compare OVS to OSA PSG parameters in a case-control study. Methods We matched OVS and OSA patients for age, sex, BMI, and AHI, then compared the PSG data. We also compared additional measures of hypoxic burden, including desaturation severity, desaturation slope, and desaturation recovery. Results We suitably matched a total of 83 patients in each group. There were no differences in sleepiness (Epworth Sleepiness Scale; OVS 10±5 vs. OSA 10±5, P = 0.978), PVT lapses (OVS 30±30 vs. OSA 25±30, P = 0.260), or comorbidity. The OVS group has poorer quality of life (SF36 Physical Component Score (OVS 37±11 vs. OSA 41±11, P = 0.001). There were no differences in sleep duration (OVS 274±82 min vs. OSA 284±78 min, P = 0.383) or sleep efficiency (OVS 63% vs. OSA 66%, P = 0.204). There were no differences in the number of ≥3% desaturations scored (OVS 149±117 vs. OSA 125±126, P = 0.072). The OVS had greater desaturation severity (0.40% vs. 0.25%; P<0.035) and greater sleep time below SpO2 90% (11% vs. 1%; P<0.001). There were no differences in desaturation duration, desaturation slope, or recovery slope. Discussion/Conclusion When controlling for demographics and AHI, OVS shows no differences in sleep study parameters except for oxygen saturation.