Biomarkers of the development and progression of diabetic polyneuropathy

Abstract

To study the diagnostic potential of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGFA) and their high affinity receptors (TrkB, VEGFR2) in the development and progression of diabetic polyneuropathy. The main group consisted of 65 patients with diabetes mellitus and confirmed DPN. The comparison group included 14 people with diabetes mellitus without DPN. The control group consisted of 15 healthy individuals. Clinical characteristics of DPN were evaluated with VAS, PainDetect, TSS, NSS, NDS scores. The degree of polyneuropathy was verified by electroneuromyography. Serum levels of the growth factors and their receptors were studied using enzyme-linked immunosorbent assay. Elevated expression of serum BDNF, VEGFA and TrkB was found in patients with DPN, regardless of the presence of symptoms. The severe stage of DPN is characterized by painless form of polyneuropathy, the deficiency of serum BDNF, VEGFA and VEGFR2 and the high serum level of TrkB. The high expression of BDNF affects the intensity of neuropathic pain, the severity of the clinical signs of DPN and is associated with the severity of axonal damage to sensory nerve fibers. The increase in the TrkB level is associated with the painless form of neuropathy and the degree of nerve fiber demyelination. Enhanced serum expression of BDNF and VEGFA is proposed as a biomarker for the development of DPN, while different concentrations of TrkB and VEGFR2 receptors can be considered as predictors of DPN severity.