Endocrine Abstracts

Introduction: Obesity and type 2 diabetes mellitus (T2DM) are commonly associated with coronary artery disease (CAD). Recent studies demonstrated that microRNAs (miRNAs) are involved in the pathogenesis of CAD.

Aim: To study miRNA-26a, microRNA-33a and microRNA-33b expression in patients with obesity.

Methods: MiRNAs were detected in peripheral blood samples of 66 patients, aged 48–65 years. Patients with BMI 30.0–39.9 kg/m² were divided into 3 groups. The 1st group included 21 patients with CAD (confirmed by coronary angiography) and T2DM, the 2nd group – 22 patients with T2DM and excluded CAD (according to the treadmill test), the 3rd group – 23 patients with obesity and excluded CAD and T2DM (‘healthy obesity’). RT-qPCR assays were used for miRNA detection.

Results: Expression of miRNA-33a was significantly different in the studied groups (P=0.009). MiRNA-33a was positively correlated with brachiocephalic arteries stenosis (r=0.453; P=0.039). MiRNA-33b was positively correlated with BMI (r=0.293; P=0.008) and HbA1c (r=0.269; P=0.016). MiRNA-33b was positively correlated with the thickness of interventricular septum (r=0.281; P=0.012); negatively with ejection fraction (r=–0.397; P=0.0003) and triglycerides (r=–0.551; P=0.009). In the third group, miRNA-33a and b were positively correlated with waist circumference (r=0.444; P=0.034 and r=0.438; P=0.036, respectively); negatively with cholesterol (r=–0.419; P=0.046 and r=–0.489; P=0.018, respectively). MiRNA-33b also negatively correlated with brachiocephalic arteries stenosis (r=–0.474; P=0.022). MiRNA-26a expression was lower in patients of the 1st group (with T2DM and CAD (P=0.003). In the first group of patients, miRNA-26a was positively correlated with LDL-cholesterol (r=0.541; P=0.011) and waist circumference (r=0.481; P=0.027). MiRNA-33a and -b were positively correlated with miRNA-26a (r=0.375; P=0.001 and r=0.353; P=0.001, respectively).

Conclusions: Expression of miRNA-33a differ in patients with CAD, T2DM, and ‘healthy’ obesity. MiRNA-33a and miRNA-33b were positively correlated with heart remodeling processes and therefore may determine the severity of cardiovascular disease in patients with obesity.