Mechanism of pain in diabetic peripheral neuropathy. Effect of glucose on pain perception in humans.

Animal studies have suggested an altered response to opiate agonists and antagonists as well as an altered pain threshold in diabetic animals. In the studies reported herein, a 50 g glucose infusion in normal subjects resulted in a significant decrease in both the threshold level of pain and the maximal level of pain tolerated, as measured by responses to electrical pain induced by a Grass stimulator. In addition, patients with diabetes mellitus were hyperalgesic when compared with normal subjects. It is concluded that elevated glucose levels and/or rapid fluxes in glucose levels result in a decrease in pain tolerance. These findings have potential clinical implications in the pathophysiology and management of painful diabetic neuropathy and the use of narcotic agents in diabetes mellitus.