The Effect of Enalapril, an Angiotensin Converting Enzyme Inhibitor, on Diabetic Neuropathy: A Double Blind Random–Allocated Study

OBJECTIVE: Diabetes mellitus is one of the most common endocrine diseases with micro-vascular complications and is a common cause of polyneuropathy. We studied the effect of enalapril on electrophysiologic criteria and clinical symptoms of patients with type II diabetes and sensory neuropathy. MATERIALS AND METHODS: A double blind study was conducted on 45 Patients with type II diabetes and neuropathy. They were normotensive and randomly divided into case and control groups. The case group received oral enalapril 2.5 mg twice a day for 3 months. The control group received placebo. We evaluated the changes in symptoms and electrophysiologic findings. RESULTS: In case group distal latency of peroneal (p=0.01), tibial (p=0.2), ulnar motor (p<0.001), ulnar sensory (p<0.001), median sensory (p<0.001), and median motor nerves (p=0.004) decreased. Amplitude of peroneal (p=0.01), tibial (p=0.01), ulnar motor (p<0.001), ulnar sensory (p<0.001), median sensory (p<0.001) and median motor nerves (p<0.001) increased. Electrophysioloic test of peroneal n. (p=0.01), tibial n. (p=0.01), ulnar motor n. (p<0.001), ulnar sensory n. (p<0.001), median sensory n. (p<0.001) and median motor n. (p<0.001) increased. We did not get any result about sural sensory potential at the beginning and the end of the study. Neuropathy symptom score was also decreased. (p=0.16) CONCLUSION: In case group electrophysiologic criteria of peroneal, tibial, median sensory and motor, and ulnar sensory and motor nerves showed significant improvement. But no significant changes were found in clinical symptoms.