BACKGROUND. Patients with type 2 diabetes mellitus (DM2) have disorders of cellular and plasma hemostasis independent of the level of glycemia, increased platelet activation, combined with microvascular angiopathy. The study of the role of genetic markers of hemostasis disorders in the formation and progression of chronic heart failure (CHF) in patients with type 2 diabetes will allow for prevention, possibly optimize treatment and improve prognosis.AIM. To reveal polymorphisms of genes of the hemostasis system in patients with type 2 diabetes mellitus and chronic heart failure with preserved ejection fraction.MATERIALS AND METHODS. The frequency of coagulation factor genetic polymorphisms was studied in patients with CHF-pEF and DM2 (52 people), CHF with reduced ejection fraction (CHF-rEF) and DM2 (49) and healthy volunteers (66), mean age 69.9±10.1 years old. DNA was isolated from venous blood according to the method of the manufacturer. Genetic polymorphisms were determined by real-time polymerase chain reaction.RESULTS. The frequencies of polymorphisms rs1799963 and rs6025 of the genes of blood coagulation factors F2 (prothrombin) and F5 (factor V of blood coagulation) in all three groups were insignificant and comparable in magnitude. In patients with CHF and DM2, the frequencies of the rs6046 polymorphism of the factor F7 gene in the heterozygous form were slightly higher (by 2.6 and 1.7 times, respectively) than in the control group, but the result was not statistically significant. The CHF-pEF and CHF-rEF groups differ in the frequencies of F13 (rs5985) and fibrinogen (rs1800790) genetic polymorphisms, but are more common in patients with CHF-rEF and DM2.CONCLUSION. Based on the results of the study, it follows that the groups of CHF-pEF and CHF-rEF differ significantly in the frequencies of polymorphisms of the studied genes, both among themselves and with the control group. The highest frequency of polymorphisms of genes, the products of which are involved in the coagulation and cellular components of hemostasis, is observed in the group of patients with DM2 and CHF-rEF.