[Pathomechanism of diabetic neuropathy: background of the pathogenesis-oriented therapy]

The pathomechanism of diabetic neuropathy remains still poorly understood, however, a broad spectrum of novel findings associated with therapeutic consequences emerged during the last decades. Both disturbed function of primary hemostasis and increased activity of coagulation system contribute to the reduced endoneurial blood flow. Increased superoxide anion production induced by hyperglycemia leads to decreased activity of glycerinaldehid-3-phosphate dehydrogenase and to consequential increased activity of alternative pathways, including the polyol-, hexosamine-, diacilglycerol protein kinase-C- and advanced glycation pathways. Advanced glycation endproducts increase the activity of the nuclear-factor kappa-B, as well as the production of vasoactive factors and cytokines (interleukin-1, -6, tumor necrosis factor alpha). The aim of pathogenetic oriented treatment is to slow down, stop or reverse the progression of neuropathy. Components of pathogenetic oriented treatment are glycaemic control, management of risk factors, benfotiamine and alpha-lipoic acid. On one hand, transketolase-activator benfotiamine inhibits alternative pathways induced by hyperglycemia (the polyol-, hexosamine-, diacilglycerol protein kinase-C-, and advanced glycation pathways), while, on the other hand, it increases the activity of the pentose-phosphate-shunt. The clinical effectiveness of benfotiamine has been shown in many international and Hungarian trials. Alpha-lipoic acid as a powerful antioxidant decreases oxidative stress and this way increases the activity of glycerinaldehid-3-phosphate dehydrogenase. Alpha-lipoic acid administered in infusion or oral treatment decreases both symptoms of neuropathy and neuropathic deficit. In conclusion, the case of diabetic neuropathy illustrates well, how widening of our knowledge on pathogenesis might contribute to successful therapy.