[Relationship between nonalcoholic fatty liver disease markers and renal function in patients with type 1 diabetes]

Recent evidence suggests that nonalcoholic fatty liver disease (NAFLD)) is associated with an increased prevalence and incidence of chronic kidney disease (CKD) in diabetic and nondiabetic subjects. The aim of this study was to explore relationship between markers of NAFLD, including concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALK), y-glutamyltransferase (GGT), ferritin and bilirubin with renal parameters, including urinary albumin excretion rate (UAE), serum creatinine and creatinine clearance in type 1 diabetic patients.

We analyzed 353 patients with type 1 diabetes. None of them showed signs of adrenal, thyroid, renal, liver or cardiovascular diseases and received drugs, apart from insulin, that could attenuate glucose metabolism, insulin sensitivity, renal or liver function. Correlations were performed to identify relationships between NAFLD associated markers with renal parameters. Urinary albumin concentration was determined by an immunoturbidimetric assay. Creatinine clearance was calculated from serum and urine creatinine concentrations and urine volume.

ALT, ALK and bilirubin significantly correlated with UAE (r=0.12, 0.14, and -0.10, respectively, all p<0.05), bilirubin and ferritin with creatinine clearance (r=0.14, and 0.21, respectively, all p<0.05), and ferritin with serum creatinine (r=0.28, p<0.05). ALT, ALK, creatinine clearance and UAE significantly correlated with HbA1c (r=0.14, 0.19, -0.14, and 0.13, respectively, all p<0.05), ALK, bilirubin, ferritin, serum creatinine and creatinine clearance with waist circumference (r=0.10, 0.13, 0.39, 0.34, and 0.29, respectively, all p<0.05), ALT, ALK and creatinine clearance with triglycerides (r=0.11, 0.25, and -0.14, respectively, all p<0.05), ALK, creatinine clearance and UAE with C-reactive protein (r=0.14, -0.18, and 0.12, respectively, all p<0.05), ALK and UAE with white blood cell count (r=0.12, and 0.24, respectively, all p<0.05).

We demonstrated that NAFLD associated markers, including ALT, ALK, bilirubin and ferritin are associated with renal parameters, especially UAE, in type 1 diabetic patients. The most plausible explanation for these findings is that the link between NAFLD and CKD may be represented by the shared risk factors and components of the metabolic syndrome. However, the published data from recent prospective studies suggest that NAFLD not only is a marker of CKD but also might play a part in the development and progression of CKD.