Autonomic neuropathy in diabetes mellitus

Aims. We analyse the different studies conducted on the prevalence, aetiopathology, clinical symptoms and treatment of diabetic autonomic neuropathy (AN), together with its involvement in the mortality of patients. Development. AN can affect any part of the nervous system to varying degrees and at different moments in time, and its prevalence is significant in any of the stages of diabetes. The aetiopathogenesis of AN results from a multifactorial process involving metabolic disorders triggered by the activation of the polyolic pathway, microangiopathy and alterations affecting the synthesis of essential fatty acids due to hyperglycemia, which is made worse by a deficient regeneration of nerve tissue. Any of the systems innervated by the autonomous nervous system can be affected; the initial symptoms are insidious and of little cause for concern until the more advanced stages of the disease. The chief dysfunctions affect the cardiovascular, digestive, genito-urinary and thermoregulatory systems. How AN courses in time varies from patient to patient and depends on the glycemic control that is carried out. Its presence is a factor that increases the mortality rate in diabetic patients. Conclusions. The prevalence of AN is notable, and the symptoms of autonomic dysfunction are usually under-diagnosed owing to its variability, lack of specificity and the wide range of symptoms. It is important to recognise this entity because of its effects on increasing morbidity and mortality, although they can be reduced by means of a strict glycemic control and specific treatment. © 2005, Revista de Neurología.