Neuropathic Pain in Type 2 Diabetes Mellitus Patients

Background and purpose: The definition, clinical presentation, and treatment of diabetic neuropathic pain were reviewed. Results: The estimated prevalence of diabetic neuropathic pain is up to 22% based on a population of 270 million in the US. Diabetic neuropathy is one of themost common complications of type 2 diabetes mellitus (T2DM). Diabetic neuropathic pain is a sensorimotor neuropathy, or a distal symmetrical polyneuropathy, which is the most common type of excruciating, refractory pain in T2DM patients. Positive symptoms include pain and paresthesia. Patients complain about burning, tingling, aching, cold sensation, lancinating pain, numbness, or pain from normal touch. Painful symptoms occur in a part (11%-32%) of neuropathic patients with diabetes and do not correlate with diminished nerve conduction velocity. Thus electrophysiological testing is rarely needed according to the recommendations of the American Diabetes Association in 2010. The multifactorial pathogenesis of diabetic neuropathy suggested by recent research includes the polyol pathway, oxidative stress, advanced glycation end products, and protein kinase C. Medications for relief of diabetic neuropathic pain are recommended to improve the quality of life. For neuropathic pain control, the efficacy of tricyclic antidepressants, gabapentin, pregabalin, opioids, and tramadol is documented. Selective serotonin noradrenaline reuptake inhibitors, topical lidocaine, and transcutaneous electrical stimulation are therapies with some evidence of efficacy. Conclusions: Treatment is a great challenge, and has to be individualized to each patient, by taking into account side effects, pain type, comorbidities, and drug interactions. As poor glycemic control may worsen diabetic neuropathic pain, it is important to achieve a glucose target as rapidly as possible.