Diagnosis and treatment of the early stages of diabetic polyneuropathy

Diabetic polyneuropathy (DPN) is the most common and earliest complication of diabetes mellitus and it may occur much earlier in patients with type-2 diabetes than in patients with type-1. Distal polyneuropathy can develop not only in diabetes mellitus, but also at the stage of prediabetes and even in patients with metabolic syndrome without impaired glycemic state. Hyperglycemia viewed as a major, but not the sole factor, responsible for development and progression DPN. The control of blood glucose as an obligatory step of therapy to delay or reverse DPN is no longer an arguable issue. Damage of peripheral nervous system in prediabetes and in the initial stages of diabetes mainly affects small nerve fibers, which also leads to disorders of the autonomic nervous system. Cardiac autonomic neuropathy diagnosed in 5-7.7% of patients at the time of diagnosis of type 1 and type 2 diabetes mellitus. For the early diagnosis of DPN, both routine assessment of peripheral sensation can be used, as well as specialized methods (sympathetic skin reactions, skin biopsy, confocal corneal microscopy, quantitative sensory tests) and validated questionnaires (Utah Early Neuropathy Scale) focused on assessing the function of small nerve fibers. Non-electrophysiological studies also were tested for early diagnosis of DPN: peripheral nerve sonoelastography, optical coherence tomography, MRI neurography, spiral positron emission CT (SPECT) with 123I-MIBG. DPN diagnosis in the pre-clinical stage very important, because treatment with diet and lifestyle intervention may be successful. The correlation between the severity of oxidative stress and the activity of antioxidant defense is considered as a potential mechanism for early nerves damage with hyperglycemia and as a possible target for therapeutic intervention. In this work, we will review prevalence, diagnostic approaches and potential treatment options for early diabetic polyneuropathy