Pulmonary Dysfunction Contributes to Nocturnal Hypoxemia Beyond Obstructive Sleep Apnea Severity in Primary Sjögren Syndrome

Background/Objectives: Pulmonary involvement is a common extraglandular manifestation of primary Sjögren syndrome (pSS) and may impair pulmonary gas exchange. Although obstructive sleep apnea (OSA) has been reported in pSS, the relationship between nocturnal hypoxemia and pulmonary dysfunction remains unclear. We investigated whether nocturnal oxygenation abnormalities in pSS are associated with pulmonary functional impairment beyond OSA severity.