Comparison Of Methods For Estimating Kidney Function In Cirrhosis

ObjectiveTo evaluate the performance of conventional creatinine-based glomerularfiltration rate (GFR) equations in subjects with cirrhosis, we compared them to theCKD-EPI creatinine-cystatin C equation (2012) in85subjects with cirrhosis. We alsoanalyzed the risk factors for renal dysfunction in cirrhotic patients.MethodsWe performed a retrospective study of145patients with cirrhosis or otherchronic liver diseases diagnosed in the First Hospital of Jilin University from June2014to Mar2015. All the data including sex, age, height, weight, surgical history,medical history, etiology and complications (ascites, primary liver cancer, infections,hepatic encephalopathy and upper gastrointestinal bleeding) were recorded accordingto medical records. Liver cancer was diagnosed based on medical history, clinicalmanifestations, laboratory tests and CT scan or MRI. Ascites was detected byultrasonography. The BMI index, body surface area, Child-Pugh score, MELD score,eGFR and other data were calculated. IBM SPSS Statistics21.0and MedCalc14.8.1were used in data analysis and graphing.Results1. Renal function of85subjects with cirrhosisTwelve had eGFR (CKD-EPI SCr-Cys C equation)<60mL/min/1.73m2in85subjects, the prevalence of renal dysfunction was14%. Patients with cirrhosis hadlower eGFR (79.4±21.2ml/min/1.73m2) than ones with chronic hepatic lesion (90.3±20.9ml/min/1.73m2)(P=0.006). The female, the elderly and subjects with urinaryprotein had lower eGFR among patients with cirrhosis (P <0.05).2. The diagnostic value of Cr and Cys C on renal function in cirrhosisYouden index demonstrated a cut-off point for Cys C to define renal dysfunctionin cirrhosis of1.56mg/L (sensitivity91.7%, specificity100%) and a point for Cr of77.85umol/L (sensitivity83.3%, specificity87.7%). Cys C had a better diagnosticvalue on renal dysfunction than Cr (AUC:0.987>0.912). 3. Comparison of several eGFR equationsThere were good correlations between the new equation (CKD-EPI SCr-Cys Cequation) and three creatinine-based equations(r=0.738,0.742,0.811, P <0.001).Paired T test showed creatinine-based equations eGFR were significantly higher thanthe new equation eGFR (P <0.001) with normal renal function (eGFR≥60ml/min/1.73m2), while there were no marked difference between MDRD and newequation (P=0.055) with abnormal kidney function (eGFR <60ml/min/1.73m2).Overall, the eGFR of three creatinine-based equations were significantly higher thannew equation (P <0.001). Bland-Altman LoA showed the differences of eGFRmeasured with Cr-based equations and Cr-Cys C equation were beyond clinicallyacceptable levels.4. Risk factors for renal dysfunction in cirrhosisSubjects with normal or abnormal renal function were similar in age, sex, BMI,Child-Pugh score, MELD score, liver cancer, ascites, hepatic encephalopathy,diabetes, prothrombin time, percentage of neutrophils, International standard ratio,total bilirubin, alanine aminotransferase and aspartate aminotransferase (P>0.05).Univariate analysis showed that white blood cell count, serum albumin, serum sodium,hemoglobin, urine protein and ascites infection of both groups were statisticallydifferent (P <0.05). Multivariate logistic regression analysis showed infected ascites(OR=14.544, P=0.001) and female (OR=4.564, P=0.044) may be independentrisk factors for renal dysfunction in cirrhosis.ConclusionThe diagnostic performance of Cr and three Cr-based equations in patients withcirrhosis was inferior in clinical practice for estimating GFR, and the CKD-EPICr-Cys C equation (2012) should be considered conventionally.