Evaluation of plasma levels of adrenomedullin and ghrelin, and their correlation with electrophysiological changes in diabetic neuropathy

OBJECTIVE: To evaluate plasma levels of adrenomedullin (AM) and ghrelin and their correlation with the electrophysiological changes in diabetic neuropathy.

METHODS: The current study was conducted from March 2008 to November 2010 at the Clinical Physiology Department, King Abdulaziz University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia on 90 females divided into 30 controls (group I), 30 controlled diabetic patients (group II), and 30 with peripheral neuropathy (group III). All electrophysiological and biochemical measurements of AM and ghrelin were investigated.

RESULTS: There was a significant decrease of motor and sensory nerve conduction velocity and prolongation of F wave response of median, ulnar, peroneal, and sural nerves in diabetic patients with neuropathy. Ankle/brachial index (A/BI) showed insignificant change in all groups compared with the control group. There was significant decrease of plasma levels of AM and ghrelin in group III compared with group I. The results revealed that AM and ghrelin were positively correlated with peripheral nerves motor and sensory conduction velocities.

CONCLUSION: The altered concentration of AM and ghrelin in diabetic neuropathy could indicate a pathophysiological role. The decline of plasma levels of AM and ghrelin in diabetic neuropathy may be a causative factor, they have neuroprotective and vasculoprotective effects, so their lack could induce neuronal injury and advancement of neuropathy, but the precise role of AM and ghrelin in the pathogenesis of diabetic neuropathy is still to be elucidated.