The Natural History of Obstructive Sleep Apnea: A Scoping Review.

Obstructive sleep apnea (OSA) is a common disorder caused by recurrent upper airway obstruction during sleep, affecting individuals across the lifespan. In children, OSA commonly results from adenotonsillar hypertrophy and may resolve spontaneously or following surgical intervention. Among adolescents and adults, OSA is more frequently associated with modifiable lifestyle factors, particularly obesity. The natural history of OSA may evolve from intermittent snoring and mild disease to moderate or severe forms if left untreated, leading to reduced health-related quality of life and overall health deterioration. Early identification of OSA, especially in mild and moderate cases, allows timely interventions to improve OSA-associated indices and may prevent progression to severe disease. Continuous positive airway pressure therapy remains the treatment of choice for adults, providing effective symptom control and reducing long-term complications, although adherence rates vary. In obese patients, sustained weight reduction represents the most effective disease-modifying strategy: a ≥5% weight loss is associated with an approximately 80% reduction in progression risk, while bariatric surgery achieves remission in up to 60-65% of cases at one year. Emerging anti-obesity pharmacotherapies have also demonstrated clinically meaningful reductions in the apnea-hypopnea index. Comorbid conditions such as hypertension, type 2 diabetes, and depression exacerbate OSA severity, impair treatment response, and complicate overall disease management. This review uniquely integrates pediatric and adult longitudinal data, treatment-modified trajectories, and emerging therapeutic approaches to provide a life-course perspective on OSA natural history, highlighting opportunities for early, phenotype-directed intervention to possibly alter disease course and long-term outcomes.