BMI and mortality in critically ill patients with COVID-19: another brick in the wall of the obesity paradox

Objective

The objective of this study was to assess the existence of the obesity paradox in patients with COVID-19 admitted to the intensive care unit.

Methods

This was a multicentric retrospective cohort study including individuals aged 18 years or older admitted to the intensive care unit with SARS-CoV-2. Data were obtained from electronic medical records. The primary outcome was in-hospital mortality. Multiple logistic regression and restricted cubic splines analyses were conducted to assess the association between BMI and mortality.

Results

From March 2020 to December 2021, 977 patients met the inclusion criteria, and 868 were included in the analysis. Obesity was identified in 382 patients (44%). Patients with obesity more often underwent prone positioning (42% vs. 28%; p < 0.001), although they used less vasoactive medications (57% vs. 68%; p < 0.001). The overall in-hospital mortality was 48%, with 44% observed in the subgroup of individuals with obesity and 50% in those without obesity (p = 0.06). Patients with BMI < 25 kg/m² had the highest mortality.

Conclusions

Obesity was not associated with higher mortality rates in critically ill patients with COVID-19. Moreover, patients with BMI < 25 kg/m² had a higher mortality rate compared with those in higher BMI categories.