Introducción
Early diagnosis and treatment of subclinical kidney damage will reduce both the risk of progression of kidney disease and the risk of developing cardiovascular complications against their background. However, diagnosing CKD in the early stages, due to the lack of specific laboratory and instrumental changes, is difficult. Based on the results of clinical and experimental studies, the relationship between non-alcoholic fatty liver disease (NAFLD) and CKD has been proven. The prevalence of CKD in patients with NAFLD ranges from 20% to 55%, and the course of these diseases is mutually aggravating.

Materiales y Métodos
The study included 60 patients - 32 women (53.3%), 28 men (46.7%). The average age of the patients was 45.9+10.9 years. Diagnoses of NAFLD and CKD were made according to the criteria of EASL and KDIGO clinical guidelines, respectively. Liver stiffness was assessed in kPa according to the METAVIR scale, the degree of steatosis in db/m by indirect ultrasound transient elastography with CAP software, which was performed on a Fibroscan 502 device (Echosens, France).

Análisis de los datos
51 patients (85%) were diagnosed with NAFLD, with 36 patients (70.6%) in the form of steatosis and 15 (29.4%) in the form of steatohepatitis. In 45 (88.2%) patients with NAFLD, subclinical manifestations of CKD were identified, among which 33 patients (73.3%) had an increased glomerular filtration rate (GFR) (> 90 ml/min/1.73 m2) and 12 (26.7%) patients showed a slight decrease (60-89 ml/min/1.73 m2). Among the patients with hyperfiltration there were only patients with NAFLD in the form of steatosis and with normal liver elasticity parameters. Among patients with reduced GFR, only 2 (16.6%) patients had liver steatosis, and 10 (83.4%) patients were diagnosed with steatohepatitis and all these patients had second stage of liver fibrosis (F2) according to Metavir. Among patients who were not diagnosed with NAFLD, only 3 (33.3%) patients did not have subclinical signs of CKD. The odds ratio (OR) for the presence of subclinical kidney disease in patients with NAFLD was 15.0 (95% CI 2.948–76.313; p <0.001).

Conclusiones
Non-alcoholic fatty liver disease may serve as a reliable marker for the early diagnosis of chronic kidney disease.