Introduction: Diabetic peripheral neuropathy (DPN) is a common and debilitating complication of diabetes mellitus which severely impairs the quality of life in patients. At present, there is no cure for DPN and treatment primarily involves alleviation of symptoms. Glucagon-like peptide-1 (GLP-1) agonists are used extensively in the treatment of type 2 diabetes for their anti-diabetic effects. However, animal studies have suggested that GLP-1 agonism may also be neuroprotective. The present pilot study sought to investigate the effect of GLP-1 agonist treatment on peripheral nerve function in vivo in patients with type 2 diabetes (T2DM).

Methods: 6 T2DM (average age = 61 ± 8, 3M:3F) patients receiving exenatide were consecutively recruited and underwent comprehensive health screening and neurological assessments including nerve conduction studies. To assess peripheral nerve function, patients underwent motor nerve excitability assessments which provided indirect information about underlying axonal ion channel function in vivo. An age, sex and neuropathy severity matched cohort of T2DM (n = 15) was also recruited for comparison.

Results: Nerve excitability parameters were significantly different between GLP-1 agonist treated T2DM (EXE) compared to those not treated with a GLP-1 agonist (nEXE). Specifically, threshold electrotonus, which provides an indication of internodal conductances in vivo was significantly different between EXE and nEXE treatment groups.

Conclusion: This study demonstrates that treatment with GLP-1 agonists has an effect on peripheral nerve function in T2DM. The investigation also demonstrates that GLP-1 agonism may be a potential treatment option for DPN. Further larger cohort studies are required to more thoroughly investigate this hypothesis.