Post-operative serum uric acid and acute kidney injury.
BACKGROUND
We hypothesized that post-operative serum uric acid (SUA) may be associated with acute kidney injury (AKI).


METHODS
In this prospective, observational study, the relationships between SUA, urine neutrophil gelatinase-associated lipocalin (uNGAL) and interleukin-18 (uIL-18), serum monocyte chemoattractant protein-1 (sMCP-1) and tumor necrosis factor-alpha (sTNF-alpha), and incidence of AKI were determined. SUA were divided into tertiles and their association with AKI investigated.


RESULTS
A total of 100 cardiac surgery patients were included for analyses. The 1st, 2nd, and 3rd SUA tertiles were associated with 15.1%, 11.7%, and 54.5% incidence of AKI, respectively. The 3rd SUA tertile, compared to the referent 1st tertile, was associated with an eightfold (OR 8.38, CI95% 2.13-33.05, p=0.002) increased risk for AKI. Patients with AKI on post-operative day 1 (n=11) were then excluded for the purpose of determining the predictive value of SUA to diagnose AKI on postoperative day 2 and during hospital stay. In comparison to the referent 1st tertile, the 3rd tertile SUA was associated with an eightfold increased risk for AKI on post-operative day 2 (adjusted OR 7.94, CI95% 1.50-42.08, P=.015) and a five-fold increased risk for AKI during hospital stay (OR 4.83, CI95% 1.21-19.20, P=.025), respectively. SUA (Area Under Curve, AUC 0.77 (CI95% 0.66-0.88, P<.001), serum creatinine (0.73, CI95% 0.62-0.84, P<.001) and sTNF-alpha (0.76, CI95% 0.65-0.87, P<.001) had the best diagnostic performance measured by the Receiver Operating Characteristics curves.


CONCLUSIONS
We conclude that post-operative SUA is associated with an increased risk for AKI and compares well to conventional markers of AKI.
Division of Nephrology, Hypertension and Transplantation, University of Florida, Gainesville, FL 32610-0224, USA. ejazaa@medicine.ufl.edu
A Ahsan
AA
Ejaz
Ganesh
G
Kambhampati
Noel I
NI
Ejaz
Bhagwan
B
Dass
Vijay
V
Lapsia
Amir A
AA
Arif
Abdo
A
Asmar
Michiko
M
Shimada
Mourad M
MM
Alsabbagh
Ravi
R
Aiyer
Richard J
RJ
Johnson
D058186:Acute Kidney Injury / Q000097:blood* / Q000453:epidemiology / Q000652:urine; D000209:Acute-Phase Proteins / Q000652:urine; D015415:Biomarkers / Q000097:blood / Q000652:urine; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D018932:Chemokine CCL2 / Q000097:blood; D016009:Chi-Square Distribution; D005260:Female; D005431:Florida / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D020382:Interleukin-18 / Q000652:urine; D007902:Length of Stay; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000652:urine; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014527:Uric Acid / Q000097:blood*
D000209:Acute-Phase Proteins; D015415:Biomarkers; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D020382:Interleukin-18; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D014409:Tumor Necrosis Factor-alpha; D014527:Uric Acid