Kizuki Yuza, Selamawit Woldesenbet, Odysseas P Chatzipanagiotou, Qaidar Alizai, Meher Angez, Lorenza Arena, Charalampos M Charalampous, Rida Ejaz, Sebastian O Ekenze, Abdulaziz Elemosho, Areesh Mevawalla, Jethro W Zih-Shuo, Timothy M Pawlik
Severe obesity was associated with higher postoperative morbidity, particularly cardiac and renal complications. BMI should be interpreted alongside nutritional status and hepatic reserve in perioperative risk assessment. The attenuated inverse associations should not be interpreted as evidence that higher BMI is protective.
BACKGROUND: The association between body mass index (BMI) and outcomes after liver resection remains controversial. We examined this association using a large real-world electronic health record cohort.
METHODS: Patients undergoing liver resection for cancer from 2017 to 2025 were identified from Epic Cosmos. BMI was categorized according to World Health Organization criteria, with normal weight as the reference. Multivariable regression, restricted cubic splines, subgroup analyses, and sensitivity analyses were performed.
RESULTS: Among 16,022 patients, class II/III obesity was associated with higher odds of any 30-day complication (aOR 1.22, 95%CI 1.09-1.36), cardiac events (aOR 1.32, 95%CI 1.16-1.51), and renal events (aOR 1.77, 95%CI 1.41-2.22). After additional adjustment for cirrhosis, ALBI grade, and malnutrition, the association with any 30-day complication persisted (aOR 1.39, 95%CI 1.23-1.57). Higher BMI was associated with shorter length of stay in the primary analysis (aIRR 0.89-0.94). Inverse associations with 90-day mortality and hepatobiliary complications were attenuated after additional adjustment.
CONCLUSION: Severe obesity was associated with higher postoperative morbidity, particularly cardiac and renal complications. BMI should be interpreted alongside nutritional status and hepatic reserve in perioperative risk assessment. The attenuated inverse associations should not be interpreted as evidence that higher BMI is protective.