Fatty liver index, albuminuria and the association with chronic kidney disease: a population-based study in China

OBJECTIVES The effects of lipid metabolism disorder on renal damage have drawn much attention. Using the fatty liver index (FLI) as a validated indicator of hepatic steatosis, this study aims to provide insight about the possible links between fatty liver and the development of chronic kidney disease (CKD). SETTING Hospital. PARTICIPANTS We performed a population-based study on 9436 subjects aged 40 years or older. PRIMARY AND SECONDARY OUTCOME MEASURES FLI is calculated using an algorithm based on body mass index, waist circumference, triglycerides and γ-glutamyltransferase. Increased urinary albumin excretion was defined according to the urinary albumin to creatinine ratio ranges ≥30 mg/g. CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² or presence of albuminuria. RESULTS There were 620 (6.6%) subjects categorised to have increased urinary albumin excretion and 753 (8.0%) subjects categorised to have CKD. Participants with higher FLI had increased age, blood pressure, low-density lipoprotein cholesterol, fasting plasma glucose, fasting insulin and decreased eGFR level. Prevalence of increased urinary albumin excretion and CKD tended to increase with the elevated FLI quartiles. In logistic regression analysis, compared with subjects in the lowest quartile of FLI, the adjusted ORs in the highest quartile were 2.30 (95% CI 1.36 to 3.90) for increased urinary albumin excretion and 1.93 (95% CI 1.18 to 3.15) for CKD. CONCLUSION Hepatic steatosis evaluated by FLI is independently associated with increased urinary albumin excretion and prevalence of CKD in middle-aged and elderly Chinese.