Effect of Liraglutide on Vascular Inflammation in Type-2 Diabetes

Despite multifactorial treatment patients with type 2 diabetes are still at high risk of cardiovascular disease. The clinical LEADER trial demonstrated a reduction in cardiovascular events in patients with type 2 diabetes treated with the GLP-1 receptor agonist liraglutide and there are a number of studies indicating that liraglutide has a positive effect on the vascular phenotype. Several of the animal or ex vivo studies suggest an anti-inflammatory mechanism behind this effect. However, no in vivo human studies have been undertaken to test this hypothesis and it would be of significance to determine the precise mechanism since atherosclerosis has large prognostic impact in patients with type 2 diabetes.

The objective of this study is to evaluate the mechanism behind the anti-atherogenic effects of liraglutide.

In a randomized, placebo-controlled, double-blind, parallel trial we will included 100 patients with type 2 diabetes. Patients will be randomized 1:1 to an active treatment period of 26 weeks or placebo for 26 weeks.

The primary endpoint is change from baseline to week 26 in vascular inflammation, assessed by Flour Deoxy Glucose (FDG)-Positron Emission Tomography/Computed Tomography (PET/CT). FDG-PET/CT is currently the only clinically available technique for specific in vivo evaluation of vascular inflammation and for quantification of the effects of medical intervention on plaque inflammation. FDG-PET of arteries has been proven very reproducible and therefore has high power to show a treatment effect in a smaller group of patients.

A number of complementary methods exist that assess different steps in the atherogenesis like endothelial function (e.g. endo-PAT, glycocalyx measurement), artery wall thickening (e.g. carotid intima media thickness), or coronary atherosclerosis (e.g. coronary artery calcium score). For comparison these other methods will be included as secondary endpoints as they are generally more accessible and less expensive.

Inclusion criteria

• Given written informed consent
• Male or female patients >50 years with type 2 diabetes (WHO criteria)
• HbA1c ≥ 48 mmol/mol (6.5 %)
• eGFR ≥ 30 ml/min/1.73 m2 (estimated by CKD-epi formula)
• Stable glucose-lowering medication (excluding oral glucocorticoids, calcineurin inhibitors, dipeptidyl peptidase 4 (DPP4) inhibitors, glucagon like peptide-1 agonists and other agents, which in the investigator's opinion could interfere with the effect of liraglutide)for at least 4 weeks before the baseline PET/CT
• Stable/no treatment of hypercholesterolemia 4 weeks before baseline PET/CT
• Must be able to communicate with the investigator and understand informed consent.

Exclusion criteria

• Type 1 diabetes mellitus
• Chronic pancreatitis / previous acute pancreatitis
• Known or suspected hypersensitivity to trial product(s) or related products
• Treatment 90 days prior to screening with oral glucocorticoids, calcineurin inhibitors, dipeptidyl peptidase 4 (DPP4) inhibitors, glucagon like peptide-1 agonists and other agents, which in the investigator's opinion could interfere with the effect of liraglutide
• Cancer or any other clinically significant disorder, except for conditions associated with type 2 diabetes history, which in the investigators opinion could interfere with the results of the trial
• Clinical signs of diabetic gastroparesis
• Previous bowel resection
• Impaired liver function (transaminases > two times upper reference levels)
• Inflammatory bowel disease
• Weight >150 kg
• Females of childbearing potential who are pregnant, breast-feeding, intend to become pregnant or are not using adequate contraceptive methods
• Known or suspected abuse of alcohol or narcotics
• Subjects with personal or family history of medullary thyroid carcinoma or a personal history of multiple endocrine neoplasia type 2