A comparative study of serum aminotransferases in chronic kidney disease with and without end-stage renal disease: Need for new reference ranges

Background: Hepatic diseases are common among chronic kidney disease patients and liver function tests particularly serum liver enzymes play an important role in diagnosing and monitoring these patients. Serum aminotransferase levels commonly fall near the lower end of the range of the normal values in patients of chronic kidney disease (CKD). High-levels of serum alkaline phosphatase (ALP) can occur in these patients due to renal osteodystrophy. Thus, the recognition of liver damage in these patients is challenging. Aim: To compare the levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and ALP among three groups - CKD patients without end stage renal disease (ESRD), patients with ESRD and healthy controls. Materials and Methods: A retrospective, hospital-based study was carried out from 100 patients’ records from each group and serum AST, ALT and ALP values were noted. Results: Our study showed that serum AST and ALT levels were significantly lower in CKD patients both without and with ESRD compared to controls. Further, these two enzyme levels were also significantly lower in CKD patients with ESRD compared to CKD patients without the condition. Serum ALP levels were significantly higher in patients with and without ESRD as compared to the controls. However, the values did not differ significantly between patients with and without ESRD. Conclusion: Levels of serum aminotransferases were low in CKD with and without ESRD and the levels become lower as the severity of CKD increases. Thus, the study established the need for separate reference ranges of serum aminotransferase in different stages of CKD.