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.