Background: Diabetic peripheral neuropathy (DPN) is a common and debilitating complication of type 2 diabetes mellitus (T2DM), often diagnosed only after significant nerve damage has occurred. Early detection of subclinical neuropathy is crucial for implementing preventative strategies. Nerve conduction studies (NCS) are objective measures of peripheral nerve function, but their utility in asymptomatic T2DM patients is still being characterized. Methodology: A cross-sectional comparative study was conducted with 50 asymptomatic T2DM subjects (mean age 54.2 ± 6.8 years) and 50 healthy controls (mean age 53.8 ± 7.1 years). Participants underwent bilateral nerve conduction studies of the median (motor and sensory) and sural (sensory) nerves. Parameters including distal motor latency (DML), motor nerve conduction velocity (MNCV), compound muscle action potential (CMAP) amplitude, sensory nerve conduction velocity (SNCV), and sensory nerve action potential (SNAP) amplitude were recorded. Glycated hemoglobin (HbA1c) and duration of diabetes were documented for the T2DM group. Independent t-tests were used for group comparisons, and Pearson correlation analysis was performed to assess associations. Results: The T2DM group showed significantly prolonged DML (Median nerve: 3.9 ± 0.5 ms vs. 3.2 ± 0.4 ms, p<0.001), reduced MNCV (Median nerve: 48.5 ± 4.1 m/s vs. 55.2 ± 3.8 m/s, p<0.001), and lower SNAP amplitudes (Sural nerve: 8.2 ± 2.9 µV vs. 15.6 ± 3.5 µV, p<0.001) compared to controls. In the T2DM group, sural SNAP amplitude showed a significant negative correlation with both HbA1c (r = -0.58, p<0.001) and duration of diabetes (r = -0.64, p<0.001). Similarly, median MNCV was negatively correlated with HbA1c (r = -0.51, p<0.001) and diabetes duration (r = -0.55, p<0.001). Conclusions: Asymptomatic T2DM subjects exhibit significant subclinical electrophysiological abnormalities consistent with early-stage neuropathy. The severity of these changes correlates with the duration of diabetes and the degree of glycemic control. NCS can serve as a valuable, objective tool for the early detection of DPN, potentially enabling timely intervention to prevent or delay clinical progression.

Neuropathy, Motor Latency, Conduction Velocity, Action Potential, Diabetes Mellitus