Ozen K. Basoglu

1 Introduction Obstructive sleep apnoea (OSA) affects up to one billion of the adult population, with less than one third experiencing clinically significant daytime symptoms (Benjafield et al. 2019). Although anatomical factors such as obesity, upper-airway crowding or craniofacial abnormalities contribute to risk, these findings are inconsistent, and the underlying aetiology of OSA remains heterogeneous (Lisik and Zou 2025).

Summary The growing number of patients with obstructive sleep apnea is challenging healthcare systems worldwide. Obstructive sleep apnea is characterized by chronic intermittent hypoxaemia, episodes of apnea and hypopnea, and fragmented sleep. Cardiovascular and metabolic diseases are common in obstructive sleep apnea, also in lean patients. Further, comorbidity burden is not unambiguously linked to the severity of obstructive sleep apnea.

The effect of positive airway pressure treatment on weight and markers of central obesity in patients with obstructive sleep apnea remains unclear. We studied the change in body weight and anthropometric measures following positive airway pressure treatment in a large clinical cohort.