Electrophysiological Changes of Sensory Nerves in Patients with Type-2 Diabetes Mellitus of Different Duration

Abstract

Background: Peripheral neuropathy is a common complication of diabetes mellitus. Among the diabetic neuropathies
symmetrical sensory polyneuropathy is the most common one. Abnormalities of sensory nerve conduction are features
of diabetic nerve damage. Significant association has been found between electrophysiological parameters of sensory
nerves and duration of metabolic derangement in patients with diabetic neuropathy. Objectives: The present study was
designed to characterize nerve conduction abnormalities of sensory nerves in subjects with type 2 diabetes mellitus of
different duration and also to assess whether duration of diabetes has any influence on the sensory nerve function.
Methods: Forty-four type 2 diabetic subjects were included in two groups:- Group B₁ consisted of 23 diabetic subjects
having duration of diabetes for 5-10 years (shorter duration) and Group B₂ consisted of 21 diabetic subjects having
duration of diabetes for 10-15 years (longer duration). Twenty-five age and BMI matched healthy subjects without
family history of diabetes were included as Group A (control) subjects. Sensory nerve conduction velocities, action
potential amplitudes and latencies of ulnar and sural nerves were measured by a standard NCV-EMG equipment. Result:
No significant changes in sensory nerve conduction parameters were observed in the group of diabetic subjects having
shorter duration of diabetes. In the diabetic group with relatively longer duration of diabetes some of the sensory nerve
conduction parameters were affected. Among them S SNAP and S NCV were significantly (P<0.01 and <0.05 respectively)
reduced in diabetic group with relatively longer duration of diabetes. Conclusion: The results of the study indicated that
neuronal dysfunction for sensory nerves appears after a prolonged exposure to hyperglycemia; there may also be some
genetic and biochemical basis (other than hyperglycemia) for early sensory sparing in type 2 diabetic population of
Bangladesh.

DOI: 10.3329/bsmmuj.v3i1.5507

BSMMU J 2010; 3(1): 9-12