Table 1 Summary of inclusion and exclusion criteria

Age > 18 years

Pregnancy

Type 1 or type 2 diabetes

Contraindication for MRI

History of lumbar surgery or disk protrusion

History of myocardial infarction, coronary heart disease or heart surgery

Risk factors for neuropathy aside from diabetes

Alcoholism

Hypovitaminosis

Malignant disease

Previous or ongoing exposure to neurotoxic agents

Chronic neurological diseases

Parkinson’s disease

Multiple sclerosis

Restless legs syndrome

Estimated glomerular filtration rate > 60 mL/min