Sleep-Disordered Breathing and Nocturnal Hypoxemia in Chronic Thromboembolic Pulmonary Disease

Abstract

Abstract Background Although sleep-disordered breathing (SDB) and nocturnal hypoxemia were known to be present in patients with chronic thromboembolic pulmonary hypertension (CTEPH), the difference of SDB and nocturnal hypoxemia between patients who have chronic thromboembolic pulmonary disease (CTEPD) with or without pulmonary hypertension (PH) at rest remain unknown. Methods Patients who had CTEPH (n = 80) or CTEPD without PH (n = 40) underwent sleep studies from July 2020 to October 2022 at Shanghai Pulmonary Hospital were enrolled. Nocturnal mean SpO2 (Mean SpO2) < 90% was defined as nocturnal hypoxemia, the percentage of time with a saturation below 90% (T90%) exceeding 10% was used to evaluate the severity of nocturnal hypoxemia. Logistic and linear regression analyses were performed to investigate the difference and potential predictor of SDB or nocturnal hypoxemia between CTEPH and CTEPD without PH. Results SDB was similarly prevalent in CTEPH and CTEPD without PH (p = 0.104), both characterized by obstructive sleep apnea (OSA). Twenty-two CTEPH patients were diagnosed with nocturnal hypoxemia, whereas only three were diagnosed in CTEPD without PH (p = 0.021). T90% was positively associated with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance in patients with CTEPH and CTEPD without PH (p < 0.001); T90% was also negatively related with CO in these patients. Single-breath carbon monoxide diffusing capacity, sex and mPAP were all correlated with nocturnal hypoxemia in CTEPH and CTEPD without PH (all p < 0.05). Conclusion Nocturnal hypoxemia was worse in CTEPD with PH; T90%, but not SDB, was independently correlated with the hemodynamics in CTEPD with or without PH.