Background: Nonalcoholic steatohepatitis or fibrosis is associated with the increased prevalence of impaired kidney function. It is not known whether nonalcoholic fatty liver (NAFL), which is steatosis without inflammation or fibrosis, is associated with renal impairment as these individuals are not candidates for liver biopsy.
Materials and methods: The study group included all liver donors who underwent a preoperative liver biopsy for various reasons. NAFL was defined as more than 5% hepatocytes having steatosis and no changes of steatohepatitis and/or fibrosis. Individuals with NAFL were compared with individuals with normal liver histology. Estimated glomerular filtration rate was calculated with the Modification of Diet in Renal Disease and Chronic Kidney Disease Epidemiology Collaboration methods.
Results: The mean age of the study group was 35±10.3 years and the mean BMI was 26±3.2 kg/m. A total of 187 adults having NAFL (80 men) were compared with 186 (88 men) individuals with normal liver histology (controls). Individuals with steatosis had significantly higher BMI (26.8±3.5 vs. 25.5±3.8 kg/m, P<0.001) and serum alanine transaminase levels (33.8±13.3 vs. 27.2±9.8 IU/l, P<0.000). There was no significant difference in the estimated glomerular filtration rate between the normal histology group and the NAFL group with Modification of Diet in Renal Disease (115±21.8 vs. 114.4±23.2 ml/min, P=0.803) and Chronic Kidney Disease Epidemiology Collaboration methods (113.6±14.8 vs. 113±14.7 ml/min, P=0.668). There was no significant difference as regards serum creatinine (0.73±0.16 vs. 0.74±0.16 mg%, P=0.536), proteinuria (P=0.121), diabetes (1 vs. 4, P=0.372), and hypertension (2 vs. 6, P=0.174) in individuals of both groups.
Conclusion: Presence of NAFL does not adversely affect renal function.