BMI and pneumonia outcomes in critically ill COVID-19 patients: an international multicenter study.

Background Previous studies unveiled a relation between the severity of COVID-19 pneumonia and obesity. The aims of this multicenter retrospective cohort study were to disentangle the association of BMI and associated metabolic risk factors (diabetes, hypertension, hyperlipidemia, current smoking) in critically ill patients with COVID-19. Methods This multicenter retrospective cohort study enrolled patients admitted in intensive care for COVID-19, in 21 centers (Europe, Israel, USA) between 02/19/2020 and 05/19/2020. Primary and secondary outcomes were the need for invasive mechanical ventilation (IMV), and 28-day mortality. Results A total of 1,461 patients were enrolled, median(IQR) age was 64 years (40.9-72.0); 73.2% males; BMI 28.1 kg/m2 (25.4-32.3); 1,080 patients (73.9%) required IMV; the 28-day mortality estimate was 36.1% (95%CI, 33.0-39.5). Adjusted mixed logistic regression model showed a significant linear relation between BMI and IMV: OR 1.27 (95%CI, 1.12-1.45) per 5 kg/m2 . Adjusted Cox proportional hazards regression model showed a significant association between BMI and mortality, which was only increased in obesity class III (≥40 kg/m2 ) (HR 1.68 (95%CI 1.06-2.64). Conclusion In critically ill COVID-19 patients, we observed a linear association between BMI and the need for IMV, independent of other metabolic risk factors, and a non-linear association between BMI and mortality risk. (NCT04391738).