Electrophysiological Evaluation Of Peripheral Nerve In Impaired Glucose Regulation And Diabetes Mellitus

0bjective The aim of the study was to evaluate the impairment of peripheral nerve in patients with Impaired glucose regulation(IGR)and diabetes mellitus(DM)through electmphysiological approach and to provide reliable information for early diagnosis.Methods We retrospectively reviewed 92 cases with IGR and 68 cases with DM in our hospital from March 2015 to March 2016.Thirty-six healthy volunteers were included as control.All participants underwent MNSI score and physical examination,motor and sensory(median,ulnar,tibial,and peroneal)nerve conduction studies,SSR test and counting motor unit number of the hypothenar muscle and extensor digitorum brevis using the Keypoint.net(Medoc Ltd)electromyogram device.Results 1.The SSR amplitude of lower limbs were reduced[0.55±0.54 mv VS 0.75±0.34,p<0.05].Distal motor latency of the median were prolonged [3.33±0.59 ms VS 3.00±0.56 ms,p<0.05] and finger1/3 SNAP amplitude of median were decreased [20.69±8.61 uv VS 25.51±10.48uv/13.46±6.56 uv VS 17.64±7.09 uv,p<0.05].Sensory conduction velocity of median nerve were lowed[50.58±8.29m/s VS 54.41±7.24m/s / 54.22±4.63m/s VS 57.69±7.01m/s,p<0.05]in IGR group,compared with control group.But median,ulnar,tibial,and peroneal nerve sensory and motor conductiont had no difference(p>0.05).2.In DM group,the SSR amplitude of extremities were reduced and latency of lower limbs are extended,The difference was statistically significant(p<0.05).The sensory nerve action potential(SNAP)amplitude of median,ulnar,tibial and peroneal nerve was significantly lower and Compound muscle action potential(CMAP)amplitude were reduced(p<0.05);Distal motor latency of the median were prolonged and finger1/3 SNAP amplitude of median were decreased,the difference was statistically significant(p<0.05);Motor unit number of the hypothenar muscle and extensor.digitorum brevis was lowed [104.98±32.66 VS 152.31±46.33,72.63±24.17 VS 95.43±23.88],the difference was statistically significant p<0.05,when compared with control group.3.Compared to IGR group,the SSR latency of lower limbs are extended[1956±321ms VS 1851±254ms,p<0.05]and the amplitude was reduced [0.36±0.50 mv VS 0.55±0.54 mv,p<0.05];SNAP amplitude of median,ulnar,tibial and peroneal nerve was significantly lower and CMAP amplitude of tibial and peroneal nerve was reduced;MUNE of the hypothenar muscle and extensor digitorum brevis was lowed the difference was statistically significant(p<0.05).4.Compared with the normal control group,the clinical symptoms(pain,numbness,burning sensation),ankle reflex,vibration perception of big toe and pressure feeling were weakened or loss in patients of IGR groups(p<0.05).Compared with the IGR group,there was a higher abnormal proportion of clinical symptoms(pain,numbness,burning sensation),ankle reflex,vibration perception of big toe and pressure feeling in DM group(p<0.05),and there was no statistical difference in other areas.5.Logistic regression analysis was used to screen the risk factors of IGR related neuropathy,and the results showed that the increase of BMI,the level of serum triglyceride and low density lipoprotein were risk factors of IGR related neuropathy.Conclusion patients with IGR presist peripheral nerve damage,mainly involving the small fiber nerve of the lower limbs.Large fibers can also be mildly affected with the disease progression,mainly axonal injuring and the lower extremity heavier than the upper limb.Obesity and dyslipidemia may be the risk factors for IGR neuropathy.