Predictive Value of C-Reactive Protein/Albumin Ratio for Acute Kidney Injury in Patients with Acute Pancreatitis

Purpose: This study aims to evaluate the predictive efficacy of the C-reactive protein/albumin ratio (CAR), a cost-effective, easily accessible, and reproducible biomarker obtained from standard blood tests, in forecasting acute kidney injury (AKI) among patients undergoing acute pancreatitis (AP). Considering that changes in the CAR are associated with AKI incidence in AP cases, this work aims to explore whether CAR can be used as the innovative, inflammation-based diagnostic marker for AKI in AP patients. Methods: The current retrospective cohort study consecutively enrolled AP patients admitted to First College of Clinical Medical Science of China Three Gorges University during the period from January 2019 to October 2023. Data were extracted systematically in electronic medical records from these hospitalized individuals, including baseline demographic and clinical characteristics. To ascertain the association of the CAR level with the development of AKI, we carried out multivariate logistic regression, adjusting for potential confounders. These confounders were initially identified through univariate regression. Furthermore, the potential effect modifiers in the relationship between CAR and AKI occurrence were explored by stratified logistic regression. Results: Totally, 1514 AP were recruited, including 257 (16.9%) with AKI. CAR was positively correlated with AKI. When adjusting for potential confounders, the AKI risk in patients in the upper CAR tertile (2.628- 22.994) increased by 83% relative to those in lower tertile (0.05- 0.289) (OR 1.83, 95% CI 1.13- 2.96, P = 0.013). The AKI risk tended to increase according to the increasing CAR tertile (P for trend = 0.013). No significant interactions were observed among subgroups based on age, sex, BMI, admission to ICU, hypertension, DM, chronic obstructive pulmonary disease, severity of AP, etiology of AP, demand for CRRT, mechanical ventilation, and blood transfusion (all P > 0.05). Conclusion: A higher CAR is significantly related to the higher AKI incidence in AP patients in the Chinese population.