Decreased blood supply to the nerves leading to hypoxia of the nerve
Yasuda and Dyck showed that blood vessel basement membrane was thicker in diabetics
Metabolic Theory
Nerve tissue is unique as it does not require insulin for glucose to be absorbed into the cells. Consequently, the glucose levels within nerve axons will be directly porportional to that of the blood. Glucose is then transformed into sorbitol and fructose which eventuallly leads to numerous biochemical and functional abnormalities. As the rate of the polyol pathway is directly dependent upon the level of glucose, persistent hyperglycemia feeds this process.
