Ｏｂｊｅｃｔｉｖｅ：To observe and evaluate whether fibroblast growth factor 23(FGF23) can be a biomarker for predicting renal function recovery in critical care patients with acute kidney injury (AKI).
Ｍｅｔｈｏｄｏｌｏｇｙ：Patients with AKI admitted to the renal intensive care unit (ICU) of Jinling Hospital from June 2014 to July 2015 were included,to analysis FGF23  level in AKI,and to compare the correlation between renal function recovery and FGF23,and analysis  risk factors affecting  prognosis of AKI.
Ｒｅｓｕｌｔｓ：104 AKI patients were included,and 60 healthy controls were included from the biological sample bank of our center.FGF23 level of AKI patients was higher than that of healthy control group.FGF23 in AKI patients was positively correlated with serum phosphate level.FGF23 level in nonrecovery group was higher than that of complete recovery group (P<005).Single factor Logistic regression analysis found that  poor prognosis of  kidney function at discharge were related with elderly age,higher FGF23,hyperphosphatemia,peak serum creatinine (SCr)   blood cystatin C,urine RBP,anemia,sepsis and chronic kidney disease (CKD).The multifactor Logistic regression analysis found that renal poor prognosis of AKI patients were associated with FGF23,CKD,age and  peak SCr.CKD  history is  the main factor influencing renal prognosis of AKI patients.The diagnostic threshold of FGF23 for judging renal function recovery of AKI was 23779 pg/ml.
Ｃｏｎｃｌｕｓｉｏｎ：FGF23 level was elevated in AKI patients,which was correlated with serum phosphate level.FGF23 could be used as a biomarker to predict renal function recovery in AKI patients.