SAT-413 Timely Hypothyroidism Treatment Reduces Cpap Need In A 50-year-old Hispanic Female With Osa

Abstract Disclosure: S. Manikonda: None. M. Ayman: None. Introduction: Obstructive sleep apnea (OSA) is a common condition that often coexists with hypothyroidism, obesity, and metabolic disorders. Hypothyroidism may contribute to OSA by causing upper airway edema, macroglossia, and decreased ventilatory drive. Continuous positive airway pressure (CPAP) is the standard therapy for moderate-to-severe OSA, but treating underlying causes may improve symptoms and reduce CPAP dependence. This case illustrates the benefit of timely thyroid hormone replacement in a patient with moderate OSA and untreated hypothyroidism. Case Presentation A 50-year-old Hispanic woman with a history of untreated hypothyroidism, obesity (BMI 37.5), hypertension, and type 2 diabetes mellitus presented with fatigue, excessive daytime sleepiness, snoring, and poor concentration. Polysomnography revealed moderate OSA with an apnea-hypopnea index (AHI) of 22. She was advised to begin CPAP therapy. Concurrent labs revealed a 14.8 µIU/mL TSH with low free T3 and T4. She was started on levothyroxine 0.1mg and monitored by endocrinology. Over three months, her thyroid function normalized (TSH < 3.0 µIU/mL), and her symptoms improved significantly, including better sleep quality and daytime alertness.A repeat sleep study six months after achieving euthyroidism showed a reduced AHI of 7, indicating mild OSA. Based on these findings and her symptomatic improvement, CPAP was discontinued. She was managed conservatively with lifestyle modifications and remained asymptomatic at six- and twelve-month follow-ups. Discussion: This case highlights the reversible nature of OSA in the setting of untreated hypothyroidism. Thyroid hormone deficiency may worsen OSA by increasing upper airway collapsibility and impairing respiratory drive. Correction of hypothyroidism in this patient led to a substantial decrease in OSA severity, allowing for safe discontinuation of CPAP therapy. While CPAP remains essential for many patients, this case emphasizes the need for evaluating and managing reversible contributors to OSA. Conclusion: In patients with moderate OSA and hypothyroidism, timely initiation of thyroid hormone replacement can significantly improve sleep-disordered breathing and reduce reliance on CPAP. Comprehensive evaluation and treatment of underlying conditions should be considered in OSA management, especially in patients with multiple metabolic comorbidities. Presentation: Saturday, July 12, 2025