Obesity and mortality in critically ill COVID-19 patients with respiratory failure.

Background: Patients with obesity are at increased risk of severe COVID-19, requiring mechanical ventilation due to acute respiratory failure. However, conflicting data are obtained for intensive care unit (ICU) mortality.

Objective: To analyze the relationship between obesity and in-hospital mortality of ICU patients with COVID-19.

Subjects/methods: Patients admitted to the ICU for COVID-19 acute respiratory distress syndrome (ARDS) were included retrospectively. The following data were collected: comorbidities, body mass index (BMI), the severity of ARDS assessed with PaO/FiO (P/F) ratios, disease severity measured by the Simplified Acute Physiology Score II (SAPS II), management and outcomes.

Results: For a total of 222 patients, there were 34 patients (15.3%) with normal BMI, 92 patients (41.4%) who were overweight, 80 patients (36%) with moderate obesity (BMI:30-39.9 kg/m), and 16 patients (7.2%) with severe obesity (BMI ≥ 40 kg/m). Overall in-hospital mortality was 20.3%. Patients with moderate obesity had a lower mortality rate (13.8%) than patients with normal weight, overweight or severe obesity (17.6%, 21.7%, and 50%, respectively; P = 0.011. Logistic regression showed that patients with a BMI ≤ 29 kg/m (odds ratio [OR] 3.64, 95% CI 1.38-9.60) and those with a BMI > 39 kg/m (OR 10.04, 95% CI 2.45-41.09) had a higher risk of mortality than those with a BMI from 29 to 39 kg/m. The number of comorbidities (≥2), SAPS II score, and P/F < 100 mmHg were also independent predictors for in-hospital mortality.

Conclusions: COVID-19 patients admitted to the ICU with moderate obesity had a lower risk of death than the other patients, suggesting a possible obesity paradox.