Body Composition May Be a Novel Presurgical Risk Factor for Acute Kidney Injury among Clear Cell Renal Cell Cancer Patients Undergoing Radical Nephrectomy

Patients with renal cell carcinoma (RCC) undergoing nephrectomy are at risk for acute kidney injury (AKI). Prior studies have focused predominantly on nonmodifiable surgical AKI risk factors. We conducted the first investigation of body composition features and AKI to identify factors that could improve presurgical risk stratification and be targeted in future interventions. We analyzed data from 1199 patients with stages I-III, clear cell RCC undergoing radical (RN) or partial nephrectomy (PN) from 2000 to 2020. AKI was defined as a serum creatinine (sCr) increase by 0.3 mg/dL within 48 h or a 1.5-fold increase in sCr within 7 days. Preoperative computed tomography (CT) scans were segmented to determine quantities and radiodensities of adipose tissue and skeletal muscle using Automatica software. Multivariable generalized linear models estimated 7-day risk differences (RD) and 95% confidence intervals (CI) within surgical subgroups. AKI was more frequent among patients undergoing RN (66%) than PN (26%). For RN, only higher visceral adipose tissue (VAT) quantity was significantly associated with greater AKI risk (RD per 40-unit increase 5.2 [95% CI: 1.3, 9.2]). We initially detected a similar association in PN, but after multivariable adjustment for all body composition features, associations were attenuated and became nonsignificant. Associations between presurgical body composition and AKI risk vary by surgery type. Higher VAT quantity increased AKI risk only among RN patients. If confirmed, CT-derived VAT quantity may be a novel presurgical imaging characteristic that could be used to inform treatment selection or modified to decrease postoperative AKI risk in RN patients.