The Research Of Serum TGR5 Level In People With Different Glucose Tolerance

Objective: With the changes of lifestyle and diet structure,the incidence of metabolic diseases such as obesity and type 2 diabetes mellitus is increasing,it has been a global public health problem,so it is necessary to investigate the mechanism for metabolic diseases.G protein-coupled bile acid receptor 1(TGR5)is a kind of cell surface bile acid G protein-coupled receptor.TGR5 is widely expressed in multiple tissues,it can regulate the metabolic processes through many ways such as inducing the insulin secretion by acting on islet beta cells and intestinal endocrine cells directly or indirectly.The aim of this study is to investigate the level of serum TGR5 in people with different glucose tolerance and the relationship between TGR5 and blood glucose,blood lipid,total bile acid.Methods: Subjects were enrolled from people who came for health screening in Health Examination Center of Hebei Province General Hospital from June to July,2016.After writting informed consent,Oral glucose tolerance test with 75 g of glucose load(OGTT)was proceeded in all participants.According to the results of OGTT,participants were divided into normal glucose tolerance group(NGT group),impaired glucose regulation group(IGR group)and type 2 diabetes mellitus group(T2DM group).Eventually,a total of 100 individuals were enrolled.The blood pressure,height,weight were measured and the body mass index(BMI)calculated.Peripheral venous blood samples were collected from all participants.Blood glucose,blood lipids and total bile acid were analyzed by automatic biochemical analyzer.Serum fasing insulin(Fins)was detected by electrochemical luminescence method.Glycosylated hemoglobin(HbA1c)was detected by high performance liquid chromatography.Serum TGR5 was detected by enzyme-linked immunosorbent assay.The general data,biochemical index and the level of serum TGR5 were analyzed,then the relationship between TGR5 and blood glucose,blood lipid,total bile acid were evaluated.Results:1 The general characteristics of participants in NGT,IGR and T2 DM groups1.1 The baseline clinical characteristics of participantsThe difference of age,blood pressure and BMI among NGT group,IGR group and T2 DM group were compared using one-way ANOVA analysis.The results indicated that there were no statistical differences in age and BMI among the three groups(P>0.05).Compared to the NGT group,the level of SBP and DBP were significantly higher in IGR group(P=0.019,P=0.003).The level of SBP and DBP in T2 DM group were signifIcantly higher than NGT group and IGR group(P<0.05).1.2 Comparison of biochemical index1.2.1 Comparison of blood glucose related indexThe differences of blood glucose related index between three group were compared.The results indicated that compared to the NGT group,the levels of FBG,PBG and HbA1 c were signifcantly higher in IGR group(P<0.001,P<0.001,P=0.024).The levels of FBG,PBG and Hb A1 c in T2 DM group were significantly higher than NGT group(P<0.001)and IGR group(P<0.001),the level of Fins was lower in T2 DM than NGT group and IGR group(P=0.001,P<0.001).1.2.2 Comparison of blood lipidThe differences of blood lipid related index between three group were compared.The results indicated that the level of TC and LDL-C in IGR group were significantly higher than NGT group(P=0.049,P=0.014).The T2 DM group had higher level of TG than the NGT group(P=0.016).Compared to the NGT and IGR groups,T2 DM group had lower level of HDL-C(P=0.008,P=0.001).1.2.3 Comparison of total bile acidThe difference of TBA were compared.The results indicated that therewere no statistical differences in TBA among the three groups(P >0.05).2 The level of serum TGR5 and sex difference analyses among NGT,IGR and T2 DM group2.1 The serum level of TGR5 of different glucose tolerance participantsThe results indicated that the level of serum TGR5 in IGR group was significantly lower than NGT group(P=0.033).The level of serum TGR5 was significantly lower in T2 DM group than NGT and IGR group(P<0.001,P=0.001).2.2 The serum level of TGR5 according to the sexAccording to the sex,we divided the participants in each group into two subgroups: male subgroup and female subgroup.The differences between subgroups were compared using Mann-Whitney U analysis.The results indicated that the male in T2 DM group had higher level of serum TGR5 than female(P=0.035).However,the serum level of TGR5 in male had the higher tendency than female in group of NGT and IGR,but had no statistical difference(P=0.308,P=0.213).3 The correlation analyses of serum TGR5 level with biochemical index3.1 The correlation of serum TGR5 level with blood glucose related indexIn this study,we detected the correlation of serum TGR5 level with FBG,PBG,Fins,HbA1 c by Pearson correlation coefficient or Spearman,s correlation coefficient.The results indicated that serum TGR5 level in NGT group was negatively associated with FBG(r=-0.466,P=0.019).There were no significant relations between serum TGR5 level and FBG,PBG,Fins,HbA1 c in IGR group.In group of T2 DM,serum TGR5 level was negatively associated with FBG,PBG and HBAIc(r=-0.544,P<0.001,r=-0.568,P<0.001,r=-0.458,P < 0.001),but had no significant correlations with Fins(P=0.124).3.2 The correlation of serum TGR5 level with blood lipidIn this study,we detected the correlation of serum TGR5 level with TC,TG,HDL-C and LDL-C by Pearson correlation coefficient or Spearman,s correlation coefficient.The results indicated that serum TGR5 level in NGTgroup was positively associated with TG(r= 0.619,P=0.005).Serum TGR5 level in IGR group was negatively associated with TC and LDL-C(r=-0.503,P=0.012,r=-0.558,P=0.005).In group of T2 DM,serum TGR5 level was negatively associated with LDL-C(r=-0.304,P=0.014).3.3 The correlation of serum TGR5 level with TBAIn this study,we detected the correlation of serum TGR5 level with TBA use Spearman,s correlation coefficient.The results indicated that serum TGR5 level had no significant correlations with TBA.4 The influence factors of serum TGR5 levelIn this study,we treated TGR5 as an independent factor,using Multiple linear stepwise regression analysis to detected the influence of FBG,PBG,Fins,Hb A1 c,TC,TG,HDL-C,LDL-C and TBA on the level of serum TGR5.The result indicates that FBG was the important factor of serum TGR5 level in people with different glucose tolerance.Conclusion:1 The level of TGR5 was lower in IGR group and T2 DM group than that in NGT group.In group of T2 DM,male serum TGR5 was higher than that of female.2 In IGR group,serum TGR5 level was negatively associated with TC and LDL-C.In T2 DM group,serum TGR5 level was negatively associated with FBG,PBG and Hb A1 c.FBG was the important influence factor of serum TGR5 level in people with different glucose tolerance.