Recently published work has demonstrated in animals that the control of pancreatic hormone secretion is due, at least in part, to the action of GLP-1 on the via the autonomic nervous system. Therefore, rhe investigators hypothesized that altered autonomic nervous system could explain, at least in part, the altered therapeutic efficacy of DPP-IV inhibitors observed in some patients. Our aim is to validate this concept in humans.~The objective of this physiopathological, monocentric, comparative, open, parallel study is to compare the effect of a single administration of a DPP-IV (vildagliptin: Galvus ®) over two populations of type 1 diabetic patients: a control group of 12 patients without diabetic autonomic neuropathy (NA) and a group of 12 patients with NA.~This proof of concept study will enrol type 1 diabetic patients to avoid confounding factors related to endogen insulin secretion and frequent polymedication of type 2 diabetic patients. The response will be evaluated for each patient by the relative difference between pre-and post-glucagon concentrations following a test meal, measured in the absence and presence of treatment with DPP4 inhibitor. Expected results: the DPP-4 inhibitor should lead to a reduction of about 20 to 30% of the glucagon level in patients without NA and a smaller or no decrease in patients with NA.
The purpose of this study is to compare the effect of a single administration of a DPP-IV inhibitor (vildagliptin: Galvus ®) versus no treatment over two populations of diabetic patients: without diabetic autonomic neuropathy (NA, i.e. the control group) and with diabetic autonomic neuropathy (i.e. the neuropathy group). The investigators hypothesize that the therapeutic efficacy of DPP-IV inhibitors is partly mediated by the autonomic nervous system. This hypothesis will be validated if a lower glycemic response to DPP-IV inhibitor treatment is observed for the neuropathy group compared to control.