Pulmonary hypertension related to sleep-disordered breathing.

PURPOSE OF REVIEW: Sleep-disordered breathing (SDB) is an increasingly recognized contributor to WHO Group 3 pulmonary hypertension (PH). This review examines the epidemiology and pathophysiology linking SDB to PH, evaluates the evidence base for sleep-directed therapies in modifying pulmonary hemodynamics, and highlights emerging treatment modalities that may be able to alter disease course. RECENT FINDINGS: The mechanisms underlying SDB-related PH are multifactorial, including recurrent nocturnal hypoxemia, altered intrathoracic pressures, and obesity-driven metabolic and inflammatory dysregulation. Positive airway pressure therapy remains the cornerstone of treatment of SDB-related PH, though mandibular advancement devices and hypoglossal nerve stimulation offer viable alternatives. Hypoxic burden, rather than apnea-hypopnea index alone, is increasingly recognized as a better predictor for cardiovascular and pulmonary vascular outcomes in SDB. Long-term oxygen therapy provides hemodynamic benefit in patients with resting hypoxemia, though evidence is limited in those with isolated nocturnal desaturation. SUMMARY: SDB is an underdiagnosed and clinically important contributor to PH. Early identification and treatment, particularly with positive airway pressure therapy when indicated, can meaningfully reduce pulmonary arterial pressures. Future research should prioritize prospective trials examining the direct impact of glucagon-like peptide-1 receptor agonists and bariatric surgery on pulmonary hemodynamics and standardize the use of hypoxic burden as a clinical endpoint.