Low Body Mass Index in Patients With Gastrointestinal Tumors Is Associated With Higher Rates of Postoperative Intensive Care Unit Admission

Accumulating evidence demonstrated that low body mass index (BMI) is associated with adverse surgical outcomes. This study aimed to investigate the relationship between BMI and postoperative intensive care unit (ICU) admission in patients undergoing surgery for gastrointestinal tumors. We conducted a retrospective analysis using data from the Vital Signs Database (VitalDB). Patients were stratified into four BMI categories: underweight (BMI <18.5 kg/m2), normal weight (18.5-22.9 kg/m2), overweight (23.0-27.4 kg/m2), and obese (≥27.5 kg/m2). Demographic characteristics, intraoperative variables, in-hospital mortality, and ICU admission rates were analyzed. Binary logistic regression was performed to identify independent predictors of ICU admission. Among 2052 patients analyzed, the underweight group exhibited the highest ICU admission rate (24.1%) compared to normal weight (15.2%), overweight (10.5%), and obese groups (14.5%; p < 0.001). Hospital stays were significantly prolonged in underweight patients (11.4 ± 12.9 days, p < 0.001). Logistic regression identified underweight status as an independent risk factor for ICU admission (odds ratio [OR] 1.78; 95% confidence interval [CI] 1.20-2.64), and it remained an independent risk factor after adjusting for other risk factors (OR 2.17; 95% CI 1.28-3.67). Patients with gastrointestinal tumors and a BMI <18.5 kg/m2 have an increased risk of postoperative ICU admission and prolonged hospital stays.