Role of Platelet to Albumin Ratio for Predicting Persistent Acute Kidney Injury in Patients Admitted to the Intensive Care Unit

Yuanwei Zhai; Xiaoqiang Liu; Yu Li; Qionghua Hu; Zhengwei Zhang; Tianyang Hu


BMC Anesthesiol. 2023;23(242) 

In This Article

Abstract and Introduction


Background: The aim of this study was to investigate the prognostic role of platelet to albumin ratio (PAR) and in persistent acute kidney injury (pAKI) of patients admitted to the intensive care unit (ICU).

Methods: We involved pAKI patients from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database and eICU Collaborative Research Database (eICU-CRD). Receiver operating curve (ROC) analysis was performed to evaluate the optimal cut-off PAR.

Results: A total of 7,646 patients were finally included in the present study. The optimal cut-off value of PAR was 7.2. The high-PAR group was associated with pAKI (hazard ratio [HR]: 3.25, 95% CI: 2.85–3.72, P < 0.001). We also performed this in the validation cohort, the results further confirmed that the high-PAR group was associated with pAKI (HR: 2.24, 95% CI: 1.86–2.71, P < 0.001). The PAR exhibited good pAKI predictive abilities in the original cohort (C-index: 0.726, 95%CI: 0.714–0.739) and in the validation cohort (C-index: 0.744, 95%CI:0.722–0.766) Moreover, as a systemic inflammatory indicator, PAR depicted better predictive ability compared to other systemic inflammatory indicators.

Conclusion: The present study manifested that elevated PAR could predicts pAKI in patients admitted to ICU. PAR may be an easily obtained and useful biomarker to clinicians for the early identification of pAKI.


Acute kidney injury (AKI) is commonly occurs with a high incidence which represents a global public health problem in patients admitted to the intensive care unit (ICU) and is associated with significant morbidity and mortality.[1–3] Reported mortality in ICU patients with AKI accounts for approximately 36–67% depending on AKI definition.[2,4] Although efforts have been made to curb AKI progress to chronic kidney disease (CKD) and end-stage kidney disease (ESKD), there remains a considerable proportion of patients presenting to ICU who required renal replacement therapy (RRT).[5,6] Moreover, the AKI occurrence in ICU increases the length of stay, the need for more vasopressors drugs, and increased the cost of services and health care systems.[7,8]

Since the 2017 Acute Disease Quality Initiative (ADQI) workgroup proposed standard definitions of transient and persistent AKI (pAKI) based on the potential impact of AKI duration on outcomes,[9] numerous investigators explored the outcomes of different types of AKI. Previous evidence indicated that two-thirds of patients with AKI resolve their renal dysfunction rapidly and there still almost one-third of patients progress to pAKI. pAKI patients exhibited an increased risk of CKD, ESKD, prone to receive RRT, and reduced survival compared to those transient AKI patients.[10,11] Considering the important role of pAKI in the prognosis of critically ill patients, early and accurate risk assessment is of critical importance for clinical management in ICU patients to receive early interventions.

Clinicians are seeking clinically meaningful predictors or biomarkers for pAKI in ICU patients. A recent study intended to assess novel candidate biomarkers to predict pAKI in critically ill patients and found that urinary C-C motif chemokine ligand 14 (CCL14) is a predictive biomarker for pAKI in critically ill patients.[12] Shen et al. reported that 24-h procalcitonin change is a good predictor of pAKI in critical patients.[13] However, these biomarkers are not easily obtained upon admission to clinical. A simple and easily accessible prognostic biomarker for early risk stratification of pAKI in patients admitted to ICU is needed.

Platelet to albumin ratio (PAR) is a widely used biomarker clinically based on routine laboratory tests which reflect the systemic inflammatory state and nutrition status, has been reported to predict several disease settings.[14,15] However, limited data have been presented on the relationship between PAR and pAKI in critically ill patients. This study sought to investigate the role of PAR in predicting pAKI in patients admitted to ICU.