Relations of Glycosylated Hemoglobin and Parameters of Nerve Conduction Study in Diabetic Peripheral Polyneuropathy

ABSTRACT

OBJECTIVE: This study was performed to determine the relations of glycosylated hemoglobin (HbA1c) and parameters of nerve conduction study (NCS) in diabetic peripheral polyneuropathy patients. METHOD: Prospectively, total 40 patients with non-insulin dependent diabetes mellitus were included in the study. NCS was performed on median, ulnar, posterior tibial, deep peroneal, superficial peroneal, and sural nerves. Distal latency and conduction velocity (CV) of compound muscle action potential (CMAP), distal latency and amplitude of sensory nerve action potential (SNAP) were used as parameters of NCS. Multiple linear regression analysis were used to analyze the relations of HbA1c and parameters of NCS, after adjustment for age, height, weight, and disease duration of diabetes mellitus. RESULTS: HbA1c level had an inverse relation to CV of median motor nerve (beta= 1.272, p<0.01), ulnar motor nerve (beta= 1.287, p<0.01), posterior tibial nerve (beta= 0.982, p<0.05), and deep peroneal nerve (beta= 1.449, p<0.05). CONCLUSION: This study indicates that HbA1c level was inversely related to motor nerve CV, and that sustained hyperglycemia may be involved in demyelination of motor nerves. Analysis of motor nerve CV related to HbA1c is expected to be useful in the follow-up or efficacy study of diabetes mellitus neuropathy as baseline data.