Abdominal obesity phenotype is associated with COVID-19 chest X-ray severity score better than BMI-based obesity

Purpose: Chest X-ray (CXR) severity score and BMI-based obesity are predictive risk factors for COVID-19 hospital admission. However, the relationship between abdominal obesity and CXR severity score has not yet been fully explored. Methods: This retrospective cohort study analyzed the association of different adiposity indexes, including waist circumference and body mass index (BMI), with CXR severity score in 215 hospitalized patients with COVID-19. Results: Patients with abdominal obesity showed significantly higher CXR severity scores and had higher rates of CXR severity scores ≥ 8 compared to those without abdominal obesity (P< 0.001; P= 0.001, respectively). By contrast, patients with normal weight, with overweight and those with BMI-based obesity showed no significant differences in either CXR severity scores or in the rates of CXR severity scores ≥ 8 (P= 0.104; P= 0.271, respectively). Waist circumference and waist-to-height ratio (WHtR) correlated more closely with CXR severity scores than BMI (r= 0.43, P< 0.001; r= 0.41, P< 0.001; r= 0.17, P= 0.012, respectively). The area under the curves (AUCs) for waist circumference and WHtR were significantly higher than that for BMI in identifying a high CXR severity score (≥ 8) (0.68 [0.60–0.75] and 0.67 [0.60–0.74] vs 0.58 [0.51–0.66], P= 0.001). A multivariate analysis indicated abdominal obesity (risk ratio: 1.75, 95% CI: 1.25–2.45, P< 0.001), bronchial asthma (risk ratio: 1.73, 95% CI: 1.07–2.81, P= 0.026) and oxygen saturation at admission (risk ratio: 0.96, 95% CI: 0.94–0.97, P< 0.001) as the only independent factors associated with high CXR severity scores. Conclusion: Abdominal obesity phenotype is associated with a high CXR severity score better than BMI-based obesity in hospitalized patients with COVID-19. Therefore, when visiting the patient in a hospital setting, waist circumference should be measured, and patients with abdominal obesity should be monitored closely.