Para-Aortic Adipose Tissue as Predictor of Severe Acute SARS-CoV-2 Infection

Background/Objectives: Obesity is a well-established risk factor for severe COVID-19, largely mediated by chronic inflammation originating from adipose tissue. The role of para-aortic adipose tissue (PAT)—a component of perivascular adipose tissue in COVID-19 severity remains poorly understood. This study aimed to investigate the association between PAT volume and the severity of acute SARS-CoV-2 infection and to evaluate its potential as a predictor of severe COVID-19. Methods: This retrospective single-center cohort study included 279 hospitalized patients with confirmed COVID-19 pneumonia. Based on disease severity, patients were divided into moderate and severe groups. PAT volume was measured around the aorta semi-automatically on a single chest computed tomography. Clinical, laboratory, and imaging data were analyzed. Logistic regression and receiver operating characteristic curve analysis were performed to assess the predictive value of PAT volume. Results: Patients with severe COVID-19 were significantly older, had higher body mass index. PAT volume differed significantly between groups, with a greater proportion of higher values in the severe group. Severe cases also exhibited significantly elevated levels of C-reactive protein, ferritin, and D-dimer, and lower oxygen saturation. Correlation analysis revealed significant associations between PAT volume and age, BMI, ferritin, the extent of lung involvement and SpO₂. Multivariable logistic regression confirmed that log-transformed PAT volume was independently associated with severe COVID-. The optimal threshold for initial PAT volume was 0.35 cm³ (sensitivity: 51.2%, specificity: 67.1%). Conclusions: PAT volume is independently associated with severe COVID-19, and values exceeding 0.35 cm³ may serve as a predictor of disease severity in hospitalized patients.