This article is more than 5 years old. Information may no longer be current.
Nerve fiber loss linked to severe diabetic neuropathy
Click Here to Manage Email Alerts
As severity of diabetic neuropathy increases, the skin on the foot experiences loss of intra-epidermal nerve fibers, advanced endothelial dysfunction and reduced vascular endothelial growth factor expression.
To determine the role of vascular endothelial growth factor (VEGF) in the preservation of peripheral nerve function in diabetic neuropathy, researchers at the University of Manchester in England analyzed 53 patients with diabetes and 12 non-diabetic controls.
The researchers examined skin biopsies from the dorsum of the foot and performed neurological evaluations, electrophysiology, quantitative sensory and autonomic function tests.
They found that as severity of neuropathy increased, intra-epidermal nerve fiber density gradually decreased. Compared with controls, patients with diabetes experienced a reduction in the intensity of staining for epidermal VEGF-A (P,.01). Those patients with diabetes who had mild and moderate neuropathy (P,.01) had reduced dermal blood flow response to acetylcholine. – by Stacey L. Adams
Diabetes Care. 2008;31:140-145.
The association between decreased VEGF expression and peripheral neuropathy has been reported and is the main goal of an ongoing clinical trial, which aims to increase VEGF expression in the peripheral tissues with the hope of improving symptoms and pathologies of diabetic neuropathy. The study by Quattrini, et al in Diabetes Care further supports this idea by showing that VEGF expression is decreased in the skin of diabetic patients with severe neuropathy. However, all of these data are correlative and it is not clear whether the decreases in VEGF are causing neuropathy or the atrophy of the tissue is leading to the decreases in metabolic need, and thus cause a subsequent decrease in VEGF expression and capillary density. The results of the clinical trial will be important for several reasons. First, there are few specific treatments for diabetic neuropathy; second, the result will be supportive of the theory that decreased VEGF is responsible for neuropathy; and third, this mode of increasing VEGF is clinically feasible since decreases in VEGF expression are also observed in the myocardium and peripheral limbs of diabetic patients. Thus, this mode of treatment may also be applicable to cardiovascular complications of diabetes. Like any new potential treatments, its adverse effects have to be evaluated. This is especially true for any treatments that are trying to increase VEGF expression in diabetic patients, since increased VEGF expression is a major cause of diabetic proliferative retinopathy.
– George L. King, MD
Professor of Medicine at Harvard Medical School and Research Director at Joslin Diabetes Center, Boston