Obstructive sleep apnea (OSA) is associated with altered respiratory mechanics, including diaphragmatic function. Ultrasonography provides a non-invasive tool to assess diaphragmatic structure and performance, which may correlate with OSA severity.

Obstructive sleep apnea (OSA) is associated with altered respiratory mechanics, including diaphragmatic function. Ultrasonography provides a non-invasive tool to assess diaphragmatic structure and performance, which may correlate with OSA severity. The aim of the study is to evaluate diaphragmatic function in OSA patients using ultrasonography and to investigate its relationship with OSA severity and sleep-related parameters.

Inclusion Criteria:

• Patients visiting the Sleep Disordered Breathing (SDB) Unit at the Chest Medicine Department and diagnosed with obstructive sleep apnea (OSA) were included if they met the following criteria:
• Age 18-65 years.
• Willingness to participate in the study.

Exclusion Criteria:

• Patients were excluded if they had any of the following conditions:
• Refusal to participate in the study
• Age <18 or >65 years
• Systemic organ failure, including heart failure, stroke, renal failure, or liver failure; Uncontrolled diabetes mellitus
• Diagnosed obesity hypoventilation syndrome (OHS) or other sleep disorders apart from OSA
• Chronic respiratory diseases such as COPD, bronchial asthma, or restrictive lung disease
• OSA patients already receiving therapy (CPAP, oral appliances, or upper airway surgery)
• Neuromuscular disorders or other conditions affecting diaphragmatic function (malnutrition, chest trauma, or immobility)
• Use of steroids or uncontrolled autoimmune diseases.

Patients visiting the Sleep Disordered Breathing (SDB) Unit at the Chest Medicine Department and diagnosed with obstructive sleep apnea (OSA) were included if they met the following criteria: Age 18-65 years.; OSA group: Newly diagnosed OSA confirmed by full-night polysomnography (PSG) with apnea-hypopnea index (AHI) > 5 events/hour; Control group: Patients with AHI < 5 events/hour on PSG; Willingness to participate in the study.