Central Processing of Gut Pain in Diabetic Patients With Gastrointestinal Symptoms

OBJECTIVE: To evaluate the brain's responses to painful visceral and somatic stimuli in diabetic patients with gastrointestinal symptoms. RESEARCH DESIGN AND METHODS: The sensitivity to electrical esophageal and median nerve stimulations was assessed in 15 healthy volunteers and 14 type 1 diabetic patients with autonomic neuropathy and gastrointestinal symptoms using a euglycemic-hyperinsulinemic clamp. Evoked brain potentials were recorded. RESULTS: Patients had reduced sensitivity to esophageal (48%; P < 0.001) and median nerve (80%; P < 0.001) stimulations. They also had increased (8.8%; P = 0.007) and nonreproducible (P = 0.006) latencies of evoked potentials in response to esophageal stimulations, with 26% reduction in amplitude (P = 0.011). No potential differences were seen to median nerve stimulations. In diabetic patients, the topographic location of the first peak in potentials was more central (P < 0.001) and gastrointestinal symptoms correlated with characteristics of brain potentials (P = 0.049). CONCLUSIONS: This study supports that diabetes induces changes in peripheral visceral nerves as well as in the central nervous system.