Nonalcoholic fatty liver disease predicts chronic kidney disease in nonhypertensive and nondiabetic Korean men

In the absence of significant research, we performed a prospective study to examine the association between nonalcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). The study cohort comprised a total of 8329 healthy men, with normal baseline kidney functions and no proteinuria, working in a semiconductor manufacturing company and its 13 affiliates. Alcohol intake was assessed with a self-reported questionnaire. Biochemical tests for liver and metabolic function and abdominal ultrasonography were done. Chronic kidney disease was defined as either the presence of proteinuria or a glomerular filtration rate (GFR) of <60 mL/min per 1.73 m(2). Cox proportional hazards model was used to estimate hazard ratios in the model for CKD. During 26717.1 person-years of follow-up, 324 men developed CKD. Nonalcoholic fatty liver disease was associated with the development of CKD (crude relative risk, 2.18; 95% confidence interval [CI], 1.75-2.71); and this relationship remained significant even after adjustment for age, GFR, triglyceride, and high-density lipoprotein cholesterol (adjusted relative risk [aRR], 1.55; 95% CI, 1.23-1.95). The association between NAFLD and incident CKD was evident in the NAFLD group with elevated serum gamma-glutamyltransferase (GGT) (aRR, 2.31; 95% CI, 1.53-3.50), even after adjustment for age, GFR, triglyceride, and high-density lipoprotein cholesterol, but not in the NAFLD group without elevated GGT (aRR, 1.09; 95% CI, 0.79-1.50) (P = .008 for interaction). To summarize, NAFLD with elevated GGT concentration was associated with an increased CKD risk among nondiabetic, nonhypertensive Korean men, irrespective of metabolic syndrome. (C) 2008 Elsevier Inc. All rights reserved.