Study On Correlation Between Abdominal Adiposity And Proinsulin, Insulin Resistance

Objective:To investigate the blood lipid, insulin,C peptide , proinsulin of abdominal adiposity person in type 2 diabetes mellitus and normal glucose tolerance subjects and explore the correlation between them and insulin resistance. The premise is that all of the subjects'weight are normal.Methods: According to the guideline of normal weight(BMI:18.5 kg/m2～24kg/m2) and demand of this study, 65 cases of type 2 diabetes mellitus patients (T2DM)and 65 cases of normal glucose tolerance subjects(NGT)were selected,the two groups were devided into two subunits as abdominal adiposity group and non abdominal adiposity group according to waist circumference(WC).Under fasting situaition, all of subjects'anthropometric measurements include height,weight,waist circumference, hip circumferece and some laboratory measurements such as blood glucose,blood lipid were measured;In addition,the remanent blood serum was collected which was used to measure immunoreactive insulin(IRI)(radioimmunity assay, RIA ),C peptide(CP)(RIA ) and proinsulin(PI)concentration (enzyme linked immunosorbent assay, ELISA).Between T2DM group and NGT group, and between the subunits both in T2DM and NGT group,to compare blood lipid,IRI,CP,PI concentration and insulin resistance index(HOMA-IR) by analysis of variance;and analyze correlation between waist circumstance and blood lipid,IRI,CP,PI and HOMA-IR.Result:(1)Blood lipid:①Between T2DM and NGT: The TG concentration in abdominal adiposity group of T2DM(A) was more than (C), and HDL-C concentration in non abdominal adiposity group of T2DM (B) was less than non abdominal adiposity group of NGT (D). All of these were statistically significant difference.②Between subunits: In T2DM group, the TG, TC and LDL-C concentration were higher significantly in A group compared to B group; In NGT group, the TG and LDL-C concentration were higher significantly in C group than D group, but the HDL-C was just opposite. After adjustment of BMI, there was still significantly difference of TC between A and B,so was LDL-c between C and D.(2) IRI,CP,PI and HOMA-IR:①Between T2DM and NGT: The CP,PI and HOMA-IR in A group were more than C group, and CP,HOMA-IR in B group were more than D group.All of these were statistically significant difference.②Between subunits: In T2DM group, The IRI,CP,PI and HOMA-IR in A group were more than B group, and the fore-two parameters were not statistically significant difference, but the post- two parameters were. In NGT group,compared with D group,the IRI,CP,PI and HOMA-IR were higher in C group which were not significant difference. After adjustment of BMI, there was still significantly difference of HOMA-IR in T2DM,but PI was not.(3)Spearman correlation analyses:①WC and BMI were related with all of the blood lipid parameters.And the coefficient of correlation of WC was higher than BMI.②WC and BMI were related with all of these parameters. And the coefficient of correlation of WC was higher than BMI.③The associations between IRI,CP,PI and HOMA-IR were positive correlation.④The waist-to-hipratio(WHR) has no correlation with these parameters. Conclusion:(1)Both in type 2 diabetes mellitus patients and normal glucose tolerance subjects with normal weight,blood lipid are significantly different between subunits,even after adjusted BMI.And WC is association with all the blood lipid.so it indicates that the blood lipid is associated with abdominal adiposity even in normal weight adults.(2) In normal weight adults of type 2 diabetes mellitus, abdominal adiposity subjects displaye more significant insulin resistance(IR) than non abdominal adiposity subjects. (3)Although the insulin resistance markers are no significant difference between subunits of normal glucose tolence group, the blood lipid presente significant difference,and the result of former may be due to shortage of subjects. The man who is normal BMI but high WC is also belonged to high risk group of abnormal metabolism,we can call them metabolically obese normal–weight (MONW) people.And we should intervene such person by life style and drug if necessary at earlier period. (4)WC is associated with insulin resistance,and the correlation is stronger than BMI.(5)Proinsulin is associated with HOMA-IR,and the coefficient of correlation is higher than insulin.So proinsulin may be a more sensitive IR index.