OBJECTIVE The effects of nonalcoholic fatty liver disease on the risk of end-stage renal disease (ESRD) remain unclear. We investigated the association between the fatty liver index (FLI) and risk of ESRD in patients with type 2 diabetes.

METHODS This population-based observational cohort study enrolled patients with diabetes who underwent health screening between 2009 and 2012 and utilized data from the Korean National Health Insurance Services. The FLI functioned as a surrogate marker for the presence of hepatic steatosis. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate < 60 ml/min/1.73 m² calculated using the Modification of Diet in Renal Disease equation. We performed Cox proportional hazards regression.

RESULTS Incident ESRD developed in 19,476 of 1,900,598 patients with type 2 diabetes during a median follow-up of 7.2 years. After adjusting for conventional risk factors, patients with high FLI scores had a higher risk for ESRD: FLI, 30-59 [hazard ratio (HR) = 1.124; 95% confidence interval (CI), 1.083-1.166]; FLI ≥ 60 [HR = 1.278; 95% CI, 1.217-1.343] compared with those with FLI < 30. The association between a high FLI score (≥ 60) and incident ESRD was more prominent in women than in men (male, FLI ≥60: HR, 1.106; 95% CI = 1.041-1.176 and female, FLI ≥ 60: HR, 1.835; 95% CI = 1.689-1.995). The association between a high FLI score (≥ 60) and the risk of ESRD differed according to baseline kidney function. High FLI scores increased the risk of ESRD (HR = 1.268; 95% CI, 1.198-1.342) in patients with CKD at baseline.

CONCLUSION High FLI scores are associated with a greater risk of ESRD in patients with type 2 diabetes with CKD at baseline. Close monitoring and appropriate management of hepatic steatosis may aid in preventing the progression of kidney dysfunction in patients with type 2 diabetes and CKD.