IS OSCILLOMETRY USEFUL IN OBSTRUCTIVE SLEEP APNEA?

<bold>Introduction:</bold> Oscillometry, assessing respiratory impedance based on resistance and reactance, is emerging in obstructive pathologies. To date, there are few studies that describe its usefulness in obstructive sleep apnea(OSA). Our study compares oscillometry values in OSA and non-OSA patients, and analyze results based on OSA severity. <bold>Material and methods:</bold> Prospective study conducted in Getafe University Hospital, Spain, from January to December 2023. 60 patients, aged 18-75 years, were recruited;30 with OSA and 30 without, confirmed through respiratory polygraphy. Classification into mild, moderate, or severe OSA was based on apnea-hypopnea index. All completed the Epworth Sleepiness scale and underwent spirometry and oscillometry. Patients with abnormal spirometry, body mass index>30, current or former smokers with pack-year index ≥10 and those with concomitant respiratory diseases were excluded. Oscillometry followed ERS 2020 recommendations, using Oostveen reference values and ResmonPROV3M equipment. <bold>Results:</bold> 60 patients analyzed, 52% men, median age 48 years. OSA group:10 mild, 10 moderate,10 severe. Clinical characteristics are described in Table1. Statistically significant lower inspiratory reactance at 5Hz was observed in OSA, with no other oscillometry differences(Table2). Subgroup analysis by OSA severity revealed no significant differences in oscillometry results(Table3). <bold>Conclusions:</bold> Results suggest limited utility of oscillometry in non-obese OSA patients. Previous studies observed differences in resistances and reactance at 5Hz but focused on obese population, a possible confusion factor. However, statistically significant differences were observed in inspiratory reactance at 5Hz between OSA/non-OSA group. Further studies are necessary to validate these findings.