Exaggerated orthostatic hypotension as first sign of diabetic autonomic neuropathy in the elderly.

Long-standing diabetic subjects have an impaired sympathetic nervous system activity as a consequence of autonomic neuropathy. Moreover, in this latter group of subjects the parasympathetic rather than the sympathetic nervous system seems firstly impaired by glucose metabolism derangements. In the present study we show that, in aged diabetic subjects with a short duration of the disease (less than 5 years), and who are free from diabetic complications, it is possible to evidence a primary compromise of sympathetic rather than parasympathetic nervous system activity since a greater rate of orthostatic hypotension occurred. In the light of the well-known age-related changes in the physiopathology of cardiovascular activity, we hypothesize that in aged diabetic patients, even after a short duration of disease, sympathetic compromise precedes the derangement of parasympathetic nervous system activity.