(1458) Assessing the Impact of Body Mass Index on Sepsis Patients: Is There a Heightened Effect?

Introduction: The global rise in obesity rates has drawn attention to its dual impact on higher morbidity in the general population and its paradoxical effects on sepsis patients. This study aims to investigate the association of body mass index (BMI) with outcomes in sepsis patients.

Methods: In this retrospective observational study, we analyzed 8,962 sepsis patients admitted to the Mayo Hospitals from August 2018 to September 2022 (IRB 20-008691). Patient data is extracted from the sepsis database. The cohort was categorized into six BMI groups: class 1 obese (n=1606, median BMI: 32.18 kg/m2), class 2 obese (n=861, median BMI: 37.18 kg/m2), class 3 obese (n=898, median BMI: 44.8 kg/m2), normal (n=2645, median BMI: 22.5 kg/m2), overweight (n=2576, median BMI: 27.3 kg/m2), and underweight (n=385, median BMI: 17.04 kg/m2). Statistical analysis was performed using BlueSky v10.3.1

Results: Our study included 8,962 mostly male (55.55%), white (92.25%), and non-Hispanic (94.3%) patients, with a median age of 70.5 years and a BMI of 27.66 kg/m2. 8,404 (93.8%) survived, while 558 (6.2%) did not.

Non-survivors had higher median age (75.5 vs 71.0, p< 0.001), lactate level (3.7 vs 2.1, p< 0.001), CAD (50.7% vs 45.6%, p=0.018), CHF (59.7% vs 52.1%, p< 0.001), septic shock (39.8% vs 5.0%, p< 0.001), CRRT (15.8% vs 1.8%), vasopressor (43.9% vs 6.6%, p< 0.001), diuretic (62.2% vs 42.4%, p< 0.001), and MV requirements (13.4% vs 7.4%, p< 0.001). The median BMI (26.88 vs 27.72, p=0.01), the incidence of DM (41.4% vs 48.6%, p< 0.001), and MAP (73.33 vs 90.33, p< 0.001) at admission were lower in non-survivors.

Comorbidity rates (HTN, DM, CKD, CHF, COPD) increased across class 1, 2, and 3 obesity groups, with class 3 obesity having the highest burden. Mortality rates in class 2 (4.6%) and 3 obesity (4.8%) were lower than in class 1 (5.5%) and normal BMI groups (7.4%) (p=0.007).

Higher BMI was initially associated with lower odds of mortality in the unadjusted analysis (OR=0.98, 95% CI: 0.96, 0.99). However, after adjusting for baseline demographics, comorbidities, and MAP at admission, BMI did not independently predict mortality (p=0.65).

Conclusions: In unadjusted analysis, BMI was linked to lower in-hospital mortality in sepsis patients. However, in the adjusted analysis, no significant association was observed.