Comparative Analysis of Sepsis Outcomes Across Body Mass Index Groups: A Retrospective Cohort Study

Background/Objectives: The relationship between body mass index (BMI) and clinical outcomes in sepsis patients remains controversial, with some studies suggesting an "obesity paradox" and others indicating increased risks for underweight individuals. This study aims to further explore the impact of BMI on mortality and other specific sepsis outcomes. Methods: This was a retrospective cohort study of adult patients with sepsis admitted to the intensive care unit (ICU) from 1 January 2021 to 31 December 2023. Patients were divided into four groups according to BMI category. The primary outcome of this study was ICU mortality. Secondary outcomes included the development of septic shock, acute respiratory distress syndrome, 30- and 90-day mortality, ICU and hospital length of stay, and vasopressor- and/or ventilation-free days. Results: A total of 559 patients were included in the study. Among these, 51 were in the underweight group, 206 were in the normal weight group, 158 were in the overweight group, and 184 were in the obese group. The primary outcome of ICU mortality was not significantly different among all BMI groups (p-value > 0.05). Similarly, all secondary outcomes were not significantly different between the groups. Conclusions: Our findings demonstrate that BMI in sepsis patients is not associated with worse clinical outcomes. Further prospective research is warranted to confirm these findings on a larger scale.