Correlation between Compound Muscle Action Potential Amplitude of Extensor Digitorum Brevis Muscle Following Proneal Nerve Stimulation and HbA1C in Type-II Diabetic Patients

Diabetic peripheral neuropathy (DPN) is a common sequela of diabetes. Late diagnosis of DPN may result in ulcer and amputation of the lower limbs. Electrodiagnostic (EDX) testing is the golden standard for DPN assessment. However, due to the limitations of EDX testing, the estimation of EDX indices using a regression model is of utmost importance. Herein, we sought to determine the correlation between compound muscle action potential (CMAP) amplitude of extensor digitorum brevis muscle following peroneal nerve stimulation and HbA1C in type-II diabetic patients.
From among 730 diabetic females, we enrolled 33 patients with the mean age, weight, height, body mass index (BMI), fasting blood sugar (FBS), and HbA1C of 48.30±7.36 years, 69.68±8.38 kg, 1.59±0.07 m, 27.32±3.24 kg/m2, 180.94±52.09 mg/dl, and 8.65±0.28%, respectively. Using EMG/NCV 4000S system, the amplitude of CMAP of extensor digitorum brevis (EDB) muscle following the stimulation of peroneal nerve was quantified. Then, using HbA1C and BMI as predictor variables, stepwise multiple regression analysis was performed in SPSS 22 to estimate CMAP amplitude. P-value less than 0.05 was considered statistically significant.
Only HbA1C was entered into the equation. The regression equation was =9.354 (-0.638)* HbA1C. Multiple adjusted R2 showed that HbA1C could explain 34% of the variations in CMAP amplitude of EDB.
HbA1C variable can predict EDX indices. Timely diagnosis of DPN by regression equations in physician’s office can reduce diabetes complications through early initiation of treatment.