A Study On The Relationship Between Serum Tumor Necrosis Factor-alpha, Leptin And Insulin Sensitivity By A Modified Minimal Model Analysis

Objective To investigate the relationship between serum tumor necrosis factor-alpha (TNF-a) , serum leptin and insulin sensitivity by a modified minimal model analysis; and then, to evaluate the risk factors for affecting insulin sensitivity . Methods (1)The reduced sample number of FSIVGTT was performed to evaluate SI, SG and AIRg in 10 non-obese subjects with NGT (NGT), 8 obese subjects with NGT (FAT) and 10 IGT subjects(IGT) by Bergman's minimal model method. (2) The serum TNF-a concentrations and serum leptin concentrations were measured by radioimmunoassay (RIA) . (3)We compared SI, SG, AIRg, serum TNF-a concentrations and serum leptin concentrations in the three groups; analyzed the risk factors for worsening insulin sensitivity by stepwise linear regression analysis. Results (1) There were significant differences in SI, SG, TNF-a between IGT and NGT groups. SI, SG were significant lower in subjects with IGT than in controls (P<0.001, P=0.048) while serum TNF-a was significant higher in subjects with IGT than in controls (P=0.002). But there were no significant differences in AIRg, serum leptin between the two groups, (2) There were no statistically significant differences in TNF-a between obese subjects with normal glucose tolerance (FAT) and controls (NGT). But SI, SG was significant lower in FAT group than in controls (PO.001, P=0.031) while AIRg, serum leptin were significant increased between the two groups (P=0.008, P=0.005). (3) SI was significant correlation with the concentrations of serum TNF-a and serum leptin (r=-0.610, P=0.001; r=-0.454, P=0.015) . After controlling the factors of age, BMI, serum glucose et al, stepwise multiple linear regression analysis suggested the independent risk predictor forworsening SI were WHR and TNF- α. Conclusions Our study suggested: (1) There was significant insulin resistance (SI was significant lower) in subjects with IGT and obese subjects with NGT than in controls. (2) The acute insulin secretion of pancreatic islets to glucose was significantly increased in obese subjects with NGT than in controls . (3) There was significant correlation between SI and serum TNF- α , serum leptin. WHR and serum TNF-α were the independent risk predictors for worsening SI.