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

Background: Peripheral neuropathy is a common complication of diabetes mellitus. Among the diabetic neuropathiessymmetrical sensory polyneuropathy is the most common one. Abnormalities of sensory nerve conduction are featuresof diabetic nerve damage. Significant association has been found between electrophysiological parameters of sensorynerves and duration of metabolic derangement in patients with diabetic neuropathy. Objectives: The present study wasdesigned to characterize nerve conduction abnormalities of sensory nerves in subjects with type 2 diabetes mellitus ofdifferent 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 subjectshaving duration of diabetes for 5-10 years (shorter duration) and Group B2 consisted of 21 diabetic subjects havingduration of diabetes for 10-15 years (longer duration). Twenty-five age and BMI matched healthy subjects withoutfamily history of diabetes were included as Group A (control) subjects. Sensory nerve conduction velocities, actionpotential 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 havingshorter duration of diabetes. In the diabetic group with relatively longer duration of diabetes some of the sensory nerveconduction 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 thatneuronal dysfunction for sensory nerves appears after a prolonged exposure to hyperglycemia; there may also be somegenetic and biochemical basis (other than hyperglycemia) for early sensory sparing in type 2 diabetic population ofBangladesh.DOI: 10.3329/bsmmuj.v3i1.5507BSMMU J 2010; 3(1): 9-1