Associations between sleep disorders, lung mechanics, and thoracic ultrasound signals in adults with obesity: a cross-sectional study

<bold>Introduction:</bold> Respiratory oscillometry (RO) and thoracic ultrasound (TUS) are sensitive tools increasingly used to detect pulmonary abnormalities. We hypothesized that there are interrelationships between lung structure/function, as evaluated by RO and TUS, and sleep disorders, as evaluated by simple tools. <bold>Objective:</bold> To correlate the risk of sleep disorders with abnormalities in lung mechanics, abnormal ultrasound signals, and anthropometric parameters in adults with obesity. <bold>Methods:</bold> Fifty individuals were assessed for the risk of obstructive sleep apnoea (OSA) using the Mallampati classification, Epworth sleepiness scale (ESS), STOP-Bang questionnaire, and Sleep Apnea Clinical Score (SACS). Patients also underwent RO, spirometry, and TUS. <bold>Results:</bold> The median age and BMI were 42 (34–58) years and 37 (33–44) kg/m², respectively. The subgroup with abnormal RO was more likely to have an ESS indicating high risk for OSA (87.5%) than the subgroup with normal RO (42.9%) (p=0.024). According to the Mallampati classification, the area under the reactance curve [14.8 (7–26) vs. 19 (13–53) kPa/L·Hz, p=0.017] was lower in participants at low risk than in those at high risk for OSA. On TUS, the frequency of patients with a Mallampati classification of high risk for OSA was higher in the subgroup with >2 B-lines (80%) than in the subgroup without >2 B-lines (25.7%) (p=0.0003). The subgroup with subpleural consolidations was more likely to have an OSA-indicative ESS (100%) than the subgroup without subpleural consolidations (41.9%) (p=0.004). <bold>Conclusion:</bold> In adults with obesity, the higher the risk of OSA was, the worse the resistive and reactive parameters measured by the RO. Abnormal RO and abnormal TUS are factors associated with a high risk for OSA.