α-Klotho: An Early Risk-Predictive Biomarker for Acute Kidney Injury in Patients with Acute Myocardial Infarction

Abstract

Background. Acute kidney injury (AKI) was a common and serious complication in patients with acute myocardial infarction (AMI). Novel biomarkers and therapies were deficient and imperative for AKI’s early diagnosis and therapy after AMI. α-Klotho was considered as an early biomarker and potential therapy for AKI recently. Previous studies reported that the expression of α-Klotho was decreased in AKI rodents, and supplement of α-Klotho alleviated kidney injury. Nevertheless, its effect has not been studied in patients presenting with AMI. Methods. A total of 155 consecutive diagnosed with AMI at emergency department whose eGFR >60 ml/min ∗ 1.73 m2 were enrolled in this prospective observational cohort study which conducted between May 2016 and April 2019 in Peking University People’s Hospital. AKI was defined according to the KDIGO criteria in 2012. At admission, the clinical data of patients were collected and serum α-Klotho was tested by ELISA. The relationship between α-Klotho, serum creatinine, eGFR, systolic pressure, BNP, LVEF, and Hgb of AKI were analyzed and their discrimination performances were compared. The association variables were calculated (adjusted odds ratio) with a confidence interval (CI) of 95% by binary logistic regression. And, we followed up the incidence of CKD and rehospitalization after patients’ discharge in one year. Our study was approved by the ethics committee (no. 2016PHB042-01). Results. AKI incidence was 17.4% (27/155) during hospitalization. Compared to patients without AKI, the AKI group had obviously higher mortality and was more female and had higher incidence of chronic kidney disease, worse cardiac function, more cardiac complications, larger doses of diuretics, and less use of angiotensin-converting enzyme inhibitors/angiotensin receptor blocker. By contrary to previous animal experiments, we found serum α-Klotho levels were increased significantly in AKI patients (740.2 ± 306.8 vs. 419.0 ± 272.6 pg/mL, p60 ml/min ∗ 1.73 m2. Higher α-Klotho levels are related to the development of AKI during hospitalization and suggest a higher prevalence of CKD after discharge. By contrary to animal experiments, whether the increased expression of α-Klotho could be a protective factor secreted by AKI after AMI, is remained to be further studied.