Study Of Relationship Between Vaspin, Adiponectin, Leptin And Diabetes Peripheral Neuropathy

BackgroundWith the increasing prevalence of diabetes, China has become a global superpower country with diabetes. Diabetic peripheral neuropathy (DPN) is a common chronic complication of diabetes without specific treatment, and the research of DPN is the current hot spots. Adipose tissue is an active endocrine organ, which can produce and secrete various adipokines. Adiponectin and leptin have been shown to closely related with the metabolic syndrome, participating in insulin sensitivity, lipid metabolism and other processes. Decreased serum adiponectin and increased serum leptin play an important role in the development process of diabetes. Recent studies have found that adiponectin and leptin are closely related to diabetic macrovascular and microvascular complications. Vaspin(visceral adipose tissue-derived serpin) is a new adipokine found in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of abdominal obesity and type 2 diabetes mellitus. Vaspin is exclusively expressed in the visceral white adipose tissue and can improve insulin sensitivity, so it is closely related to obesity, insulin resistance and glucose metabolism. Vaspin serum research in diabetic population studied abroad shows that vaspin is correlated with blood glucose, lipids and has some association with diabetes microvascular complications. Until now, rarely study evaluating the association of serum vaspin,adiponectin and leptin levels with the diabetes peripheral neuropathy complication has been undertaken. ObjectiveIn this research we detect the serum vaspin, adiponectin and leptin levels of type 2 diabetes patients with or without peripheral neuropathy,to analyze the relationship between serum vaspin, adiponectin, leptin levels and clinical metabolic indicators, and to explore the relationship between vaspin, adiponectin leptin and diabetic peripheral neuropathy.Methods105 patients with diabetes mellitus were choosen and divided into diabetes peripheral neuropahty group(DPN group,n=47) and simple diabetes group(DM group,n=58) by presence or absence of diabetes peripheral neuropahty.55 healthy controls were enrolled in this study. Patients and controls were age and sex matched. All subjects were excluded hepatic or renal failure, severe high blood pressure, heart dysfunction, cerebral vascular accident, acute or chronic infection,immune system diseases and pregnancy woman. General clinical parameters were measured and calculated, such as height, weight, waist circumference(WC), hip circumference, systolic blood pressure(SBP), dystolic blood pressure(DBP), body mass index(BMI) and waist to hip ratio(WHR). Besides routine biochemical parameters were mearured, including fasting plasma glucose(FPG), triglyccride(TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), type 2 diabetes patients also need to exam hemoglobinAlC (HbAlC).Enzyme-Linked Immuno Sorbent Assay(ELISA) was applied to measuring serum levels of vaspin and adiponectin. Leptin and insulin levels were assessed using a commercially available radioactivity immunoassay kit. Using homeostasis model assessment(HOMA-IR) to estimate insulin resistance:HOMA-IR=FPG*FINS/22.5. Statistical software SPSS 16.0 was used for data analysis. All the measurement data was expressed as x±s deviation. The experimental data were undergone with normal examination and those abnormal data were undergone with logarithmic transfonnation. For normal distributed variables, student t test or ANOVA were used; for skewed variables, Mann-Whitney U test was used; enumeration data was undergone with Chi-square test to compare the difference between or among different groups. Simple linear correlation(Pearson correlation)and stepwise regression analysis were utilized to evaluate the relations between vaspin, adiponectin, leptin and other parameters. The factors effecting diabetic peripheral neuropathy were undergone with logistic regession analysis. The difference was statistically significant if P<0.05.Result1. The levels of vaspin and leptin in DM and DPN groups were markedly higher than those of the normal group (P<0.01), vaspin and leptin in DPN group were markedly higher than those of the DM group (P<0.05). The levels of adiponectin in DPN and DM groups were lower than those of the normal group (P<0.01), adiponectin in DPN group was markedly lower than those of DM group (P<0.05).2. The serum levels of vaspin, adiponectin and leptin were higher in female than those in male (P<0.05). The concentrations of leptin in over-weight and obesity group (BMI≥25kg/m2) were higher than those in the normal weight subjects(BMI< 25kg/m2) (P<0.05), while serum vaspin and adiponectin levels were no significantly difference in the two groups.3. Pearson relation analysis in all the subjects showed that serum vaspin concentrations were positively correlated with sex, WC, FPG, FINS, HOMA-IR, TG, TC and LDL-C(P<0.05). A multiple stepwise regression analysis revealed that FPG, WC, sex and WHR were independent variables of vaspin.4. Pearson relation analysis in all the subjects showed that serum adiponectin concentrations were positively correlated with sex (P<0.01), negatively correlated with SBP, BMI, FPG, FINS, HOMA-IR, TG, TC and LDL-C(P<0.01). A multiple stepwise regression analysis revealed that HOMA-IR, TG and sex were independent variables of adiponectin.5. Pearson relation analysis in all the subjects showed that serum lepin concentrations were positively correlated with sex, WC, BMI, FPG, FINS, HOMA-IR, TG, TC and LDL-C(P<0.05). A multiple stepwise regression analysis revealed that sex, BMI, HOMA-IR,TG and LDL-C were independent variables of leptin.6. In all diabetic subjects(DM and DPN group), logistic regression analysis showed that vaspin, adiponectin and BMI were significantly associated with the presence of peripheral neuropathy in type 2 diabetes.Conclusion1. Serum vaspin and leptin levels were significantly elevated, while adiponectin level significantly declined in DPN group than those of DM group or control group, and these changes were related with obesity, insulin resistance and lipid metabolism disorder.2. Serum vaspin and adiponectin were independent effecting variables of diabetes peripheral neuropathy, indicating that high vaspin level and low adiponectin level may be related to the the process of diabetes peripheral neuropathy.3. Serum leptin level was significantly elevated in DPN group than DM group, however it was not the independent effecting variables of diabetes peripheral neuropathy, indicating that leptin may participate in the process of diabetes peripheral neuropathy by affecting metabolism of blood glucose and lipids.