Greater increase in urinary hepcidin predicts protection from acute kidney injury after cardiopulmonary bypass

Nephrol Dial Transplant. 2012 Feb;27(2):595-602. doi: 10.1093/ndt/gfr387. Epub 2011 Jul 29.


Background: Acute kidney injury (AKI) is a common and serious complication of cardiopulmonary bypass (CPB) surgery. Hepcidin, a peptide hormone that regulates iron homeostasis, is a potential biomarker of AKI following CPB.

Methods: We investigated the association between post-operative changes in serum and urinary hepcidin and AKI in 93 patients undergoing CPB.

Results: Twenty-five patients developed AKI based on the Risk, Injury, Failure, Loss, End-stage kidney disease (RIFLE) criteria in the first 5 days. Serum hepcidin, urine hepcidin concentration, the urinary hepcidin:creatinine ratio and fractional excretion of hepcidin in urine rose significantly after surgery. However, urine hepcidin concentration and urinary hepcidin:creatinine ratio were significantly lower at 24 h in patients with RIFLE-Risk, Injury or Failure compared to those without AKI (P = 0.0009 and P < 0.0001, respectively). Receiver operator characteristic analysis showed that lower 24-h urine hepcidin concentration and urinary hepcidin:creatinine ratio were sensitive and specific predictors of AKI. The urinary hepcidin:creatinine ratio had an area under the curve for the diagnosis of RIFLE ≥ risk at 24 h of 0.77 and of 0.84 for RIFLE ≥ injury. Urinary hepcidin had similar predictive accuracy. Such predictive ability remained when patients with early creatinine increases were excluded.

Conclusions: Urinary hepcidin and hepcidin:creatinine ratio are biomarkers of AKI after CPB, with an inverse association between its increase at 24 h and risk of AKI in the first five post-operative days. Measuring hepcidin in the urine on the first day following surgery may deliver earlier diagnosis and interventions.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / diagnosis*
  • Acute Kidney Injury / etiology
  • Acute Kidney Injury / mortality
  • Aged
  • Antimicrobial Cationic Peptides / blood
  • Antimicrobial Cationic Peptides / urine*
  • Area Under Curve
  • Biomarkers / blood
  • Biomarkers / urine
  • Cohort Studies
  • Coronary Artery Bypass / adverse effects*
  • Coronary Artery Bypass / methods
  • Coronary Stenosis / diagnostic imaging
  • Coronary Stenosis / mortality
  • Coronary Stenosis / surgery*
  • Creatinine / analysis
  • Creatinine / metabolism
  • Elective Surgical Procedures / adverse effects
  • Elective Surgical Procedures / methods
  • Female
  • Follow-Up Studies
  • Hepcidins
  • Hospital Mortality / trends
  • Humans
  • Male
  • Middle Aged
  • Postoperative Care / methods
  • Postoperative Complications / diagnosis
  • Postoperative Complications / mortality
  • Predictive Value of Tests
  • Preoperative Care / methods
  • ROC Curve
  • Radiography
  • Risk Assessment
  • Sensitivity and Specificity
  • Survival Rate
  • Time Factors
  • Treatment Outcome
  • Victoria


  • Antimicrobial Cationic Peptides
  • Biomarkers
  • HAMP protein, human
  • Hepcidins
  • Creatinine