Aim. To assess the level of microRNA (miR) -21, -22, -126, -221 in patients with coronary artery disease (CAD) with borderline coronary artery stenosis depending on comorbidities and sex.Material and methods. We examined 37 patients with class 1-3 stable CAD aged 49-59 years with borderline (40-70%) coronary artery stenosis. The relative level of miRNA was determined using real-time polymerase chain reaction. Statistical analysis was performed using the non-parametric Mann-Whitney U-test. P<0,05 were considered statistically significant. Results. The miR-221 level was higher in the group of patients with stable CAD with borderline coronary artery stenosis with a metabolically unhealthy obesity (MUO) phenotype, but without diabetes (p=0,042). The level of miR-22 and miR-126 was higher in the group of patients with stable CAD phenotype with borderline stenosis and diabetes (p=0,007 and p=0,034, respectively). The analysis of miR levels in stable CAD patients depending on sex, without taking into account the phenotype, found that miR-21 and miR-221 values were higher in men (p=0,021 and p=0,014, respectively). The study of the sex characteristics of miR content in relation to different phenotypes revealed an increase of miR22 levels in men with MUO and diabetes (p=0,048) and an increase of miR-126 levels in women with concomitant diabetes in the comparison both with patients without MUO and diabetes (p=0,018), as well as with MUO and without diabetes (p=0,007). Conclusion. The study of the miRNA level in patients with CAD with borderline coronary artery stenosis is of great interest and reflects a promising direction in diagnosis based on comorbid pathology. Keywords: miRNA, obesity phenotypes, coronary artery disease, borderline coronary artery stenosis. Relationships and Activities: none. 1Novosibirsk State Medical University, Novosibirsk; 2Federal Research Center of Fundamental and Translational Medicine, Novosibirsk; 3E.N. Meshalkin National Medical Research Center, Novosibirsk, Russia.><0,05 were considered statistically significant.Results. The miR-221 level was higher in the group of patients with stable CAD with borderline coronary artery stenosis with a metabolically unhealthy obesity (MUO) phenotype, but without diabetes (p=0,042). The level of miR-22 and miR-126 was higher in the group of patients with stable CAD phenotype with borderline stenosis and diabetes (p=0,007 and p=0,034, respectively). The analysis of miR levels in stable CAD patients depending on sex, without taking into account the phenotype, found that miR-21 and miR-221 values were higher in men (p=0,021 and p=0,014, respectively). The study of the sex characteristics of miR content in relation to different phenotypes revealed an increase of miR22 levels in men with MUO and diabetes (p=0,048) and an increase of miR-126 levels in women with concomitant diabetes in the comparison both with patients without MUO and diabetes (p=0,018), as well as with MUO and without diabetes (p=0,007).Conclusion. The study of the miRNA level in patients with CAD with borderline coronary artery stenosis is of great interest and reflects a promising direction in diagnosis based on comorbid pathology
