The Relationship Of Insulin-Like Growth Factor-Ⅱ To Diabetic Peripheral Neuropathy

Objective and Background:Neuropathy is a common and often debilitating complication of diabetes. Diabetic peripheral neuropathy (DPN) is heterogeneous and includes a variety of different disorders that affect the peripheral nervous system. The most common type of DPN is the predominantly sensory distal polyneuropathy, which is characterized by degeneration of sensory and autonomic fibers early in the course of the disease, and mild to moderate motor dysfunction later on. Unfortunately, the complex syndrome has proven difficult to explain and a consensus as to its cause has not emerged. It has recently to light that insulin-like growth factor-â…¡ (IGF-â…¡) have neurotrophic actions on sensory, sympathetic and motor neurons. These are the main types of neurons afflicted in this disorder. Moreover, it has been reported diabetic patients with neuropathy has significantly lower levels of serum IGF- â…¡ compared to controls and to diabetic patients without neuropathy .So IGF-â…¡ might be used in replacement therapy to ameliorate or reverse the progression of neuropathy .In this study ,we detected and compared the serum IGF- II in type 2 diabetic patients with/without neuropathy and controls to evaluate the possible relationship between IGF-â…¡and diabetic peripheral neuropathy. Design and Methods:148 patients with type 2 diabetes, as defined by the WHO criteria, were studied. They were divided into two groups based on nerve conduction velocity (NCV) (77 patients with neuropathy and 71 without neuropathy).30 healthy subjects were included as control subjects.1. Detection of serum IGF- II and other clinical parameters: blood was obtained for serum IGF-â…¡ and other clinical parameters(BG0h, BG2h, CP0h, CP2h, Ins0h, Ins2h, GH, HbA1c,et al). serum IGF- â…¡ was determined by ELISA assay.2. Detection of NCV: Median nerve and common peroneal nerve were detected by electrophysiological test to get the motor nerve conduction velocity(MCV);median nerve,ulnar nerve, sural nerve were detected to get the sensory nerve conduction velocity(SCV). Results:The peripheral neuropathy group had significant lower levels of IGF- II compared to non-peripheral neuropathy group and control subjects(P<0.05). No significant difference was found between non-peripheral neuropathy group and control subjects. The levels of serum IGF-II were positively correlated with MCV and SCV, negatively correlated with age, duration, BG2h and HbAlc. Conclusions:Decreased IGF- II in diabetic patients with peripheral neuropathy may contribute to the pathogeny of neuropathy.