Substances of endogenous intoxication syndrome (EIS), which belong to medium-mass molecules (MMM), have cardiovascular toxicity; their content is increased in conditions of chronic heart failure. However, the influence of EIS activity has been studied not enough, which determined the relevance and expediency of our study.Aim. In order to compare the laboratory-instrumental features of the course of metabolically associated liver steatosis (LS) under the conditions of pronounced and insignificant activity of EIS, 19 patients (10 men, 9 women; average age 61,8 years) with coronary artery disease (CAD), atherosclerotic cardiosclerosis, HF of I-II FC and sonographically diagnosed LS were examined. Depending on the level of MMM, patients were divided into two groups with pronounced EIS (MMM >0,6 units) and moderate activity (MMM <0,6 units), which were identical in gender and age composition, hemodynamic indicators, body mass index and area body surface. Photometric determination of MMM total and at wave lengths of 238, 254, 266, 282 nm in blood and urine was carried out; determination of blood L-arginine and urine nitrites, leptin were provided; aromaticity coefficient 238/282, hepato-steatosis index, AST/platelet ratio, nuclear intoxication index (NII), the ratio of lymphocytes and neutrophils to monocytes were calculated. All results were calculated statistically, the level of significance was taken as p<0.05.The results. Among the examined patients, 36.8% had high EIS activity (grades 2-3), and in 63.2% it was moderate (grade 1). Patients with pronounced EIS activity were characterized by hypoalbuminemia, dyslipidemia, low leptin content and higher arginine level, peripheral blood lymphopenia, and relative thinning of the heart walls. The content of MMM254,266,282 in blood was correlated with the size of the left ventricle in diastole, MMM266,282 in urine - with total cholesterol, low and very low density its particles and triglycerides, the aromaticity coefficient - with urinary nitrites. Integral hematological NII was directly proportional to diastolic pressure, and the lymphocyte/monocyte ratio - to systolic pressure. The ratio of neutrophils to monocytes and AST/platelets were correlated with the content of total bilirubin; and the hepato-steatosis index - with high-density lipoproteins and the coefficient of atherogenicity.Conclusion. Patients with concomitant metabolic-associated steatosis of the liver and a high level of EIS were characterized by metabolic disorders. Specific indicators of EIS correlated with parameters of lipid metabolism and hemodynamics.