ENDOTHELIAL PROTECTIVE EFFECT OF LIRAGLUTIDE IN TYPE 2 DIABETES MELLITUS

Background . Endothelial dysfunction underlies the development of chronic complications in type 2 diabetes mellitus. Glucose-lowering drugs with additional protective effects on endothelium are required. Objective . To study endothelial protective action of liraglutide in patients with type 2 diabetes mellitus and to detect its relation with glycemic control. Design and methods . The study was held in patients with type 2 diabetes mellitus with glycated hemoglobin 7,5–9,0 % who received metformin monotherapy. Metformin dose had been titrated for 3 months. Patients who reached glycated hemoglobin level less than 7,5 % were included in the group 1 — they had received metformin monotherapy for next 6 months. Patients with glycated hemoglobin over 7,5 % after 3 months formed the group 2, and they received liraglutide in addition to metformin for the following 6 months. At baseline, at 3, 6 and 9 months, endothelium-dependent vasodilation was evaluated by forearm microcirculation dopplerography with 0,3 % acetylcholine solution ionophoresis. Results. At baseline, patients of groups 1 and 2 showed impaired endothelium-dependent vasodilation (decrease of the reaction to acetylcholine, curve form change). There was no significant change in the linear blood flow parameters in the group 1 when euglycemia was reached by metformin monotherapy. Additional administration of liraglutide in the group 2 led to the increase in the amplitude and favourable change of the curve form. These changes were more prominent after 6 months of combined therapy. Endothelium-dependent vasodilation amplitude reached values observed in healthy subjects after 9 months from the study beginning. Conclusions. The improvement of glycemia control (euglycemia) does not have endothelial protective properties on its own. Liraglutide has its own endothelial protective action independent of glycemia control.