Subcutaneous Adipose Tissue Is Associated with Acute Kidney Injury after Abdominal Trauma Based on the Generalized Propensity Score Approach: A Retrospective Cohort Study

Abstract

Introduction: Obesity is associated with an increased risk of acute kidney injury (AKI) after trauma. However, the associations between different adipose tissue depots and AKI remain unknown. Our study aimed to quantify the effect of abdominal adiposity on AKI in trauma patients. Methods: We performed a retrospective cohort study of abdominal trauma patients who were admitted to our hospital from January 2010 to March 2020. Abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured at the level of the third lumbar vertebra using computed tomography. Causal modeling based on the generalized propensity score was used to quantify the effects of body mass index (BMI), VAT, and SAT on AKI. Results: Among 324 abdominal trauma patients, 67 (20.68%) patients developed AKI. Patients with AKI had higher BMI (22.46 kg/m² vs. 22.04 kg/m², p = 0.014), higher SAT areas (89.06 cm² vs. 83.39 cm², p = 0.151), and higher VAT areas (140.02 cm² vs. 91.48 cm², p = 0.001) than those without AKI. By using causal modeling, we found that the risk of developing AKI increased by 8.3% (p = 0.001) and 4.8% (p = 0.022) with one unit increase in BMI (per 1 kg/m²) and ten units increase in SAT (per 10 cm²), respectively. However, VAT did not show a significant association with AKI (p = 0.327). Conclusion: SAT, but not VAT, increased the risk of AKI among abdominal trauma patients. Measurement of SAT might help identify patients at higher risk of AKI.