A Clinical Research Of The Relationship Among Serum FABP4,Irisin,CMPF And Glycolipid Metabolism

BackgroundRecently,several studies of metabolic factors found that adipocyte fatty acid binding protein(FABP4)plays a key role in obesity and obesity-induced insulin resistance.As a novel cytokine,irisin induced by exercise and the higher serum irisin level can improve insulin resistance both in vitro and vivo study.However,the interaction of FABP4 and irisin has not been clarified.In another,serum CMPF concentrations in FDRs,a group at higher risk for developing T2DM,remain unknown.Moreover,less evidence exists to support the relationship between circulating CMPF and the secretion of human pancreatic P cells.Therefore,this study aimed to examine the relationships between serum FABP4 levels and irisin in a middle-aged Chinese population.And the circulating CMPF levels of patients with different glucose metabolism statuses,the correlation between CMPF and glycolipid metabolism and the potential link between CMPF and β cell function.Objective1.To investigate the serum levels of FABP4 and irisin in general population and the relationship between FABP4 and irisin.2.To investigate the serum levels of FABP4 and irisin in type 2 diabetes mellitus patients and the relationship between FABP4 and irisin.3.To investigate the serum CMPF levels in different glucose metabolism statuses,the correlation between CMPF and glycolipid metabolism and the potential link between CMPF and β cell function.MethodsFrom December 2012 to September 2013,a total of 111 apparently healthy subjects(men/women:56/55),aged 40 to 60 years old.A total of 396 participants were recruited,including 99 newly diagnosed patients with T2DM,99 patients with impaired glucose tolerance(IGT),and 198 subjects with normal glucose tolerance(NGT),including 99 FDRs.Serum FABP4,irisin and CMPF concentrations were determined using enzyme-linked immunosorbent assay.Results1,In bivariate correlation analysis,FABP4 concentrations were associated with sex(r=0.348,P<0.001).To exclude the effects of sex difference,partial correlation analysis showed that serum FABP4 concentrations were positively correlated with diastolic blood pressure(r=0.270,P=0.005)and body fat percentage(r=0.251,P=0.012)and negatively correlated with skeletal muscle mass(r=-0.335,P=0.001)and irisin(r=-0.203,P=0.033)in all of the subjects after adjusting for sex.Further multivariate stepwise linear regression analysis demonstrated that serum FABP4 levels were independently associated with skeletal muscle mass(β=-0.766±0.184,P<0.001),diastolic blood pressure(β=1.074±0.303,P=0.001)and irisin(β=-0.212±0.103,P=0.043),adjusted for age,BMI,body fat percentage,total cholesterol and HbA1C.2.Compared with NGT group serum levels,CMPF levels were elevated in the prediabetes(p=0.019),T2DM(p<0.001)and FDRs(p<0.001)groups.Serum CMPF levels were higher in FDR participants than in the prediabetesparticipants(p<0.001).Furthermore,no sex-based differences were observed with regard to the serum CMPF levels(p=0.819).Serum CMPF concentrations were negatively correlated with body mass index(r=-0.129,p=0.037),triglycerides(r=-0.203,p=0.001),the Stumvoll first-phase insulin secretion index(r=-0.150,p=0.015)and the Stumvoll second-phase insulin secretion index(r=-0.127,p=0.041).A multivariatelinear regression analysis showed that serum CMPFlevels were independently associated withtriglycerides(β=-0.451±0.128,p=0.001)andthe Stumvoll first-phase insulin secretion index(β=-0.247±0.092,p=0.008),after adjusting for FPG,body mass index and the Stumvoll second-phase insulin secretion index.ConclusionsSerum irisin levels contributed independently to circulating FABP4 in the middle-aged community population.Serum irisin levels are closely associated with glycolipid metabolism and renal function.And irisin might have a slightly antagonistic effect on FABP4.Serum CMPF levels were higher in prediabetes,T2DM and FDR participants than in NGT controls.Serum CMPF was independently associated with β cell secretion.βcell function gradually decreased with the increase of CMPF levels.Our findings suggest that serum CMPF predicts glycolipid metabolism disorders,and elevated serum CMPF concentrations might be a determinant of hyperglycemia and β cell dysfunction.