Evaluation of HUGE equation (hematocrit, urea, gender) performance for screening chronic kidney disease in clinically stable cirrhotic patients

MUSSO, CARLOS G.; CASCIATO, PAOLA; TERRASA, SERGIO; VILAS, MANUEL; JAUREGUI, JOSE; ALVAREZ-GREGORI, JOAQUIN; BELLIZZI, VINCENZO; GADANO, ADRIAN; MACÍAS NÚÑEZ, JUAN F.

INTERNATIONAL UROLOGY AND NEFROLOGY

Springer Netherlands

Año: 2016 vol. 48 p. 1555 - 1557

0301-1623

Editor,It is known that a chronically reduced glomerular filtration rate (GFR) in elderly people does not necessarily mean that they suffer from chronic kidney disease (CKD), since there is an expected GFR reduction secondary to aging [1, 2]. Based on this nephrogeriatric concept, Alvarez-Gregori et al. described and validated an equation (HUGE) for screening CKD without taking into account patient?s GFR. In this original study, medical information of 487 individuals, of both genders, and aged 16?102 was obtained. Then, these data were assessed and statistically analyzed using logistic regression techniques, and HUGE equation was derived from those parameters found as discriminative variables: hematocrit, serum urea and gender. Finally, for HUGE equation validation patient?s evaluation by two nephrologists blind between them, as gold standard for renal health status, was used [3, 4, 5].CKD is an entity frequently diagnosed in cirrhotic patients, and this kidney?liver alteration may be caused by diseases that can affect both organs (e.g., chronic virus C infection with cryoglobulinemia), or renal conditions induced by cirrhosis (e.g., Ig A nephropathy or pre-renal insufficiency induced by an increased vasomotor tone on renal circulation [6].An equation like HUGE could be useful for screening CKD in cirrhotic patients, but this equation is based on serum parameters that can be altered by cirrhosis: Hematocrit may be low due to erythropoietin resistance (chronic disease anemia), and serum urea values may be lower because of a reduced urea biosynthesis (reduced hepatic conversion of ammonium to urea) [7, 8]. Thus, we decided to originally evaluate whether HUGE equation could be an accurate tool for detecting CKD in stable cirrhotic patients despite the influence that this condition can have on its constituents.With this objective, we performed a retrospective observational study to assess the operational characteristics of HUGE equation for screening CKD in 75 patients suffering from stable liver cirrhosis (Child?Pugh A) mostly secondary to hepatitis C (43 %), selected from a population of 750 cirrhotic patients who were on follow-up during 1 year (January 2014?January 2015) by the Hepatology and Transplantation Section of the Internal Medicine Division in the Hospital Italiano de Buenos Aires (Argentina).Inclusion criteria were as follows: to have information, every 4 months, during the year of the study (2014?2015) regarding patients? serum and urine electrolytes, urea, creatinine, uric acid, hematocrit, hemoglobin, glucose, intact parathyroid hormone, urinalysis, and renal ultrasound. Then, all these patients were classified as having or not CKD after their evaluation at the end of this year (January 2015) by two independent nephrologists who based their diagnoses evaluating mainly the last year patients? medical information (medical informs, laboratories and renal images) included in their electronic medical records. The categorization in normal renal function (NRF) or CKD was based on the coincidence in one of these diagnoses performed by two nephrologists (blind between them). A matched in these two clinical nephrological diagnoses was considered to be the gold standard for determining patients? renal health status, and same criteria had been used in the original HUGE study. These two nephrologists based their medical judgment on the National Kidney Foundation KDOQI criteria for diagnosing CKD (Appendix) [9].From this evaluation resulted that 22 patients (29 %) were found to suffer from CKD, while 53 patients (71 %) were found to be free of renal disease. In this study, the prevalence of CKD in cirrhotic population was originally documented: 28 %, which was higher than in the general population (10 %) [8].In this study, it was found a significant difference in renal ultrasound images (