The axonal properties in prediabetic patients

The purpose of our study is to exam whether electrophysiology changes could be detected in prediabetes patients and to discover the possible mechanism of nerve injury in prediabetes stage. We analysis and compare the nerve excitability test data between prediabetic patients and age-matched normal control subjects. Prediabetes is defined by American diabetes association (ADA) as one of the three following: HbA1C 5.7% to 6.4%, fasting glucose 100mg/dL to 125mg/dL, and 2 hour oral glucose tolerance test 140 to 199 mg/dL. Patients with radiculopathy, myelopathy, entrapment neuropathy such as carpel tunnel syndrome, and polyneuropathy were excluded. The strength-duration time constant (SDTC) and superexcitability showed significant difference (p<0.05) between two groups. We also find increased threshold electrotonus in depolarization (TEd) and reduced relative refractory period (RRP) and refractoriness in 2.5 msec. These early changes in prediabetic patient are similar in nerve excitability feature of diabetic patients. However, the abovechanges are not found in motor axonal excitability test. Our data supports that nerve excitability test may be a useful, non-invasive, and less timedependent tool to detect peripheral nerve injury in prediabetic stage. The sensory axons are more vulnerable than motor axons. Superexcitability is themost sensitive parameter in prediabetes.