Evaluation of small airway disease with impulse oscillometry in hiv-infected adults

Background: Respiratory system involvement is common in HIV-infected patients, with airway diseases being significant non-infectious complications independent of smoking. While spirometry is the gold standard for diagnosing airway disease, Impulse Oscillometry (IOS), a non-invasive method, can identify SAD even when spirometry values are normal. This study compares demographic and IOS parameters between patients with and without SAD and establishes optimal IOS parameter cut-offs. Methods: Data on demographics and HIV status were collected from HIV-infected patients under antiretroviral treatment without known airway disease. Spirometry was conducted, followed by IOS. Patients with MMEF values below 65% were classified as having spirometric SAD, and IOS parameters were compared between groups. ROC analysis determined optimal IOS parameter cut-offs based on spirometric SAD. Results: Among 127 patients (mean age: 43.4), 62 were non-smokers. Spirometric SAD was present in 22% of non-smokers. Age, smoking history, and biomass exposure significantly differed between groups. IOS parameters R5, R5-R20, AX, and Fres were significantly higher in the SAD group. ROC analysis identified R5-R20 > 0.08 (sensitivity: 71.8%, specificity: 58.1%) and AX > 0.55 (sensitivity: 51.2%, specificity: 91.7%) as optimal cut-offs. Conclusion: Small airway disease is common in HIV patients, affecting 22% of non-smokers. Risk factors include age, smoking, and biomass exposure. IOS parameters R5-R20 and AX show diagnostic potential, with specific cut-offs aiding early detection and intervention for airway diseases in HIV-infected patients.