Elevated BMI as a Hypothetical Protective Factor in Patients With Severe Traumatic Brain Injury: A TQIP Database...

Obesity is a growing epidemic across the globe and is contributing to complications and differences in trauma outcomes. This study aims to explore the impact of obesity on morbidity and mortality in patients with traumatic brain injury (TBI), examining differences in complication rates and outcomes between patients with and without obesity, as it may play a contradictory but beneficial role in outcomes by preconditioning the brain to primary and secondary damaging factors, such as elevated intracranial pressure and cerebral ischemia. The Trauma Quality Improvement Program (TQIP) database was queried between 2021 and 2022 for adult patients with isolated and combined severe traumatic brain injuries and obesity. A total of 230,844 patients were identified as presenting with severe TBI. Patients with isolated and combined, penetrating and non-penetrating trauma were then divided into subcohorts based upon body mass index (BMI) values: underweight (<18.5 kg/m²), normal weight (18.5-24.99 kg/m²), overweight (25-29.99 kg/m²), obese (30-39.99 kg/m²), and severe obesity (≥40 kg/m²). Our analysis of 230,844 patients with severe TBI revealed that obesity in general (BMI 30+) demonstrates higher rates of comorbidities, such as diabetes (26.38% vs. 13.38%) and hypertension (51.28% vs. 39.04%). For severe obesity (BMI 40+), the risks of adjusted in-hospital mortality (AOR 1.19, p < 0.0001), cardiac arrest (AOR 1.68), and craniotomy/craniectomy (AOR 1.93) were significantly elevated. Patients in this cohort demonstrated a tendency for more resource usage in terms of length of stay in the intensive care unit (+0.87 days) and mechanical ventilation (+1.37 days) compared with normal BMI patients. Severe obesity (BMI ≥ 40) is associated with significantly higher in-hospital mortality, major complications, and increased resource utilization compared to normal weight patients. These findings do not support the hypothesis of preconditioning benefits, indicating a need for development of BMI-specific neurocritical care protocols.