Addition of liraglutide in patients with Type 2 diabetes well controlled on metformin monotherapy improves several markers of vascular function.

Aims: The aim of this study was to investigate the vascular effects of liraglutide in patients well controlled on metformin monotherapy.

Methods: Forty-four patients with Type 2 diabetes were included in the study. Main inclusion criteria were: pretreatment with metformin on a stable dosage, HbA(1c) < 53 mmol/mol (7.0%), age 30-65 years. Patients were randomized to receive additional liraglutide or to remain on metformin monotherapy. After 6 weeks (1.2 mg) and after 12 weeks (1.8 mg), venous blood was taken for the measurement of several laboratory markers characterizing vascular and endothelial function. In addition, retinal microvascular endothelial function and arterial stiffness were measured.

Results: HbA(1c) levels declined from 45 ± 4 mmol/mol (6.3 ± 0.4%; mean ± SD) to 40 ± 3 mmol/mol (5.8 ± 0.3%) during liraglutide treatment. Asymmetric dimethylarginin was reduced by liraglutide treatment from 0.39 ± 0.08 to 0.35 ± 0.06 μmol/l, E-selectin from 43.6 ± 15.4 to 40.8 ± 15.1 ng/ml, plasminogen activator inhibitor 1 from 861.6 ± 584.3 to 666.1 ± 499.4 ng/ml and intact proinsulin from 9.0 ± 7.2 to 7.0 ± 4.8 pmol/l at 12 weeks of treatment. The microvascular response to flicker light increased from 7.0 ± 15.1 to 15.4 ± 11.5% after 6 weeks and to 11.1 ± 9.9% after 12 weeks. No change could be observed for high-sensitivity C-reactive protein, monocyte chemotactic protein 1, vascular cell adhesion molecule or arterial stiffness parameters.

Conclusions: In patients with Type 2 diabetes, well controlled with metformin monotherapy, addition of liraglutide improves several cardiovascular risk markers beyond glycaemic control.