The purpose of this trial is to explore whether liraglutide has a long term effect on clinical symptoms and biomarkers in patients with diabetic neuropathy.

Inclusion Criteria:

• Abile person of Northern European descent
• Age between 18 to 65 years
• A verified diagnosis of DM type 1 for minimum 2 years (HbA1C=7%)
• Stable DM treatment (Treatment is considered stable when the patient has been treated with basal-bolus insulin, premixed insulin or continously infused insulin with an insulin dose considered stable by investigator for at least 3 months prior to screening.)
• The participants must be able to read and understand Danish.
• Peripheral diabetic neuropathy ensured by having abnormal nerve conduction velocity
• BMI equal to or above 22
• Personally signed and dated informed consent document indicating that the patient has been informed of all pertinent aspects of the trial.
• Patients willing and able to comply with the scheduled visits, treatment plan, laboratory tests and other trial procedures.

Exclusion Criteria:

• Diabetes mellitus type II
• Estimated glomerular filtration rate (s-creatinin/eGRF) < 60 ml/min/1.37m2
• Calcitonin > 25
• HbA1c level < 7%
• Patients with any clinically significant laboratory abnormalities, that in the opinion of the investigator may increase the risk associated with trial participation or may interfere with the interpretation of the trial results.
• Patients on GLP-1 receptor agonist treatment (exenatide, liraglutide or others) or pramlintide or any DPP-4 inhibitor within 3 months prior to screening.
• Other neurological and/or psychiatric disease
• Treatment of other endocrinological disease except hypothyreosis
• Malignant neoplasms requiring chemotherapy, surgery, radiation or palliative care in the previous 5 years.
• Family or personal history of multiple endocrine neoplasia type 2 (MEN2) or familial medullary thyroid carcinoma.
• Personal history of non-familial medullary thyroid carcinoma
• Known abuse or alcohol and/or medicine (Alcohol use in accordance with the recommendations by the Danish Health and Medicines Authority are allowed).
• Known allergy to liraglutide.
• Participation in other clinical trials less than 3 months prior to inclusion
• Female patients who are pregnant or lactating, or intend to become pregnant and male patients who intend to father a child during course of the study.
• In women, a serum pregnancy test will be conducted at baseline based on h-CG in the blood. The investigator will have to ensure that fertile female patients use a safe contraception method during the study and for at least 15 hours after termination of the study medication period.