Assessment of sarcopenia in the differential diagnosis of idiopathic pulmonary fibrosis patients

Objective: In this study, we aimed to determine the potential value of sarcopenia as a non-invasive biomarker in differential diagnosis by analysing computed tomography (CT) images in patients with an ordinary interstitial pneumonia (OIP) pattern. Materials and Methods: Our study included a total of 200 patients: 150 patients aged 45-90 years who underwent HRCT or chest CT for clinical evaluation at Tokat Gaziosmanpaşa University Faculty of Medicine Hospital between January 2022 and June 2024 and were diagnosed with NIP, probable NIP, or NSIP patterns on imaging; and 50 patients of a similar age group who underwent chest CT for any reason during the same period and were evaluated as normal, for a total of 200 patients. The volume of the unilateral erector spinae muscle group was measured manually from the level of the T12 vertebra and the lower section of the L1 vertebra transverse processes, and the ROI (region of interest) area of the unilateral erector spinae muscle group was measured manually at the level of the L1 vertebra transverse processes. All data were analysed using the SPSS 26.0 software package. Results: The mean muscle volume in the individuals included in the study was 83.44 ± 27.2 cm³, while the mean muscle density at the L1 level was determined to be 34.48 ± 14.8 HU. Significant differences were observed between genders in terms of both muscle volume and muscle density (p<0.001). Furthermore, when age groups were compared, it was determined that muscle density values at the L1 level were significantly lower in individuals over 65 years of age (p<0.001). A significant difference in muscle volume was also detected between the study groups (p<0.001). Conclusion: Including sarcopenia in the diagnostic process of IPF patients with an OIP pattern may provide clinicians with a practical and rapid assessment, contributing to the planning of interventions such as early rehabilitation and nutritional support. Keywords: Idiopathic Pulmonary Fibrosis, Sarcopenia, Erector spinae