Prevalence of Obstructive Sleep Apnea in HHT and HHT-specific Challenges in OSA-therapy - a Retrospective Cohort Study

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder (prevalence approx. 1:5,000-1:8,000) characterized by recurrent epistaxis, mucocutaneous telangiectasias and visceral vascular malformations. Chronic bleeding frequently leads to anemia and iron deficiency, which is associated with restless legs syndrome. Our earlier work suggested that up to 22% of affected patients may suffer from it. Nocturnal epistaxis, nasal clots, and nasal obstruction may further disturb sleep, and positive airway pressure (PAP) therapy may dry out the nasal mucosa, aggravate bleeding, and cause mask intolerance. The association between obstructive sleep apnea (OSA) and HHT has not yet been adequately studied. This retrospective, exploratory, hypothesis-generating analysis aims to determine the frequency of OSA diagnoses documented in the clinical records of our existing HHT cohort. The primary endpoint is this documented frequency, explicitly interpreted as a minimum frequency rather than a true prevalence, since not all patients were systematically screened. Secondary endpoints include details of OSA diagnostics and treatment course, complications of OSA therapy in HHT patients, OSA-related comorbidities (e.g., arterial hypertension, obesity), medication and potential adverse effects (especially respiratory depression), hypoxia-related laboratory parameters (iron status, anemia), and general patient and disease characteristics (sex, weight, height, Curaçao criteria). The findings are intended to inform a possible subsequent prospective screening phase.