Treatment of Complications to Diabetic Autonomic Neuropathy With Vagus Nerve Stimulation

Treatment of Complications to Diabetic Autonomic Neuropathy With Vagus Nerve Stimulation

The purpose of the DAN-VNS study is to investigate the effects of non-invasive vagal nerve stimulation on gastrointestinal symptoms such as nausea, vomiting, bloating, and diarrhea in people with diabetes.

The study is a randomized, double-blinded, sham-controlled, parallel group clinical trial, which will include participants with diabetes and gastrointestinal (GI) problems. These problems may be manifestations of diabetic autonomic neuropathy.

Participants are randomised to received either active non-invasive transcutaneous vagal nerve stimulation (tVNS) or inactive sham stimulation. The study period is divided in two phases. The first phase investigates the effects of short-term, high-intensity tVNS treatment on GI symptoms. The second phase investigates the effects of long-term, middle-intensity tVNS treatment. The primary outcome of both phases is subjective patient evaluation of GI symptoms by the use of validated questionnaires.

A third phase, conducted only on participants, who proved to be responsive to tVNS treatment, will investigate the acute endocrine and metabolic response to short-term tVNS in a randomised cross-over design.

Lastly, healthy volunteers will be included in a cross-sectional, descriptive study in order to provide a comparable baseline dataset.

Inclusion Criteria:

• Age ≥ 18 years
• Verified diagnosis of diabetes for a minimum of 1 year and with stable medication
• CAN-score ≥ 1 (measured by the Vagus device (Medicus Engineering, Aarhus, Denmark) OR COMPASS-31 score of ≥ 16 OR electrochemical resistance <50µS (hands) and <70µS (feet) assessed with the SUDOSCAN device
• Weighted composite score of Gastroparesis Cardinal Symptom Index (GCSI) and Gastrointestinal Symptom Rating Scale (GSRS) ≥ 2.3
• Ability to read and understand Danish
• Personally signed and dated informed consent documents
• Willingness and ability to comply with scheduled visits, treatment plan, laboratory tests and other trial procedures

Exclusion Criteria:

• Significant GI diseases not related to diabetes
• Significant cardiovascular diseases
• GI surgery within 3 months prior to study inclusion
• Swallowing disorders
• Blood pressure < 100/60 or > 160/105
• Clinically significant bradycardia or tachycardia
• Implanted portable electro-mechanical medical devices including pacemaker, defibrillator, cochlear implant, and infusion pump
• Previous surgery of the vagus nerve
• Active laser treatment for proliferative retinopathy
• Contraindications for MRI
• Any clinical 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
• Pregnancy or intention to become pregnant or father a child during the course of the study
• Participation in other clinical trials less than three months prior to inclusion, unless such a participation is judged to have no influence on the recordings