Peripheral diabetic neuropathy. Current recommendations and future prospects for its prevention and management.

One-third of diabetic patients are affected by peripheral neuropathy (PDN) in which the main aetiopathogenetic mechanism seems to be the high blood and nerve glucose content. The results of some long term trials, such as the Diabetes Control and Complications Trial (DCCT) and Stockholm studies, showed clearly that the maintenance of near-normal blood glucose levels and haemoglobin (Hb)A1c below 7.5% with intensive insulin treatment represents the best approach to primary and secondary prevention of the late diabetic complications, including PDN. After 5 years of such treatment DCCT reported that the development of clinical PDN was reduced by 64%. On the other hand, various and important problems still exist in identifying an efficacious aetiological therapy for PDN. In fact, while on the basis of current knowledge we have 2 possibilities for treatment of the pain, optimisation of glycaemic and HbA1c values and correct use of tricyclic antidepressants, none of the various substances tested has proven to be efficacious for PDN. Gangliosides, aldose-reductase inhibitors, including tolrestat, gamma-linolenic acid, levacecarnine (acetyl-L-carnitine) and antioxidants, were all shown to be of poor efficacy and often with significant adverse effects. The maintenance of near-normal glycaemic equilibrium seems currently to be the best way not only to prevent PDN but also to treat it. In the near future more long term trials, with very clear inclusion and exclusion criteria for recruitment, are needed to assist in identifying an efficacious treatment for PDN.