| Background and PurposeGestational diabetes mellitus (GDM) refers to the varying degrees of glucose metabolic disorder occurred or first discovered during pregnancy. Recent studies show that the incidence rate of GDM is rising year by year, ranging from 1.7% to 16.7%.There are many similarities between GDM and type 2 diabetes mellitus (T2DM)in etiology, pathogenesis and so on,which can cause great damage and serious complications for both mother and child. In addition, the risk of becoming T2DM in future has increased significantly, so it attracts great clinical attention. However, the etiology of GDM remains unclear by far, all therapeutic methods can not fundamentally control the progress of GDM, thus the research of seeking a therapy which can essentially improve the isletβcell's function turns into a focus. Glucagon like peptide-1(GLP-1) and Dipeptidyl peptidase-Ⅳ(DPP-Ⅳ) are the two factors discussed more currently.GLP-1 is an important incretin hormone secreted by intestinal L cells. DPP-Ⅳis a transmembrane serine protease, which can degrade various active substances concluding GLP-1 in vivo. Researches show that GDM patients may exist in a plasma disorder of GLP-1 and DPP-Ⅳ. Therefore, we used ELISA method to determine the serum levels of GLP-1 and DPP-Ⅳ, furthermore, we could explore the role and significance of them in GDM.Materials and MethodsExperimental samples:We collected 116 women in the first and third affiliated hospitals of zhengzhou university from Jan 2009 to May 2010,divided them into 3 groups:43 GDM patients(diagnosed according to Jie Liu's 7th obstetrics and gynecology edition diagnostic criteria) with mean age of (29.1±3.6), mean gestational weeks of (29.4±4.7),all cases had not given any treatment;38 gestational women with normal glucose tolerance, mean age of (28.9±4.1),and mean gestational weeks of (30.1±4.3).There were no statistical differences in maternal age, gestational weeks and pre-pregancy BMI between two groups, all pregnant women with no other complications. We randomly selected 35 non-pregnant women as control group, who were for regular examination from the identical period in the same hospitals.All women of these three groups were excluded from vital organs abnormalities, age was comparable and this trial had obtained all women's informed consent.We extracted 4ml fasting cubits venous blood from each object, collected in dry heparin test tube,3000r/min,for 15min.We got upper serum and divided into 2 parts:one was detected fasting blood glucose, insulin and glycosylated hemoglobin immediately, and the other was set aside into-70℃refrigerator.Experimental Methods:We determined the serum GLP-1 and DPP-Ⅳlevels of each women by enzyme-linked immunosorbent assay (ELISA), strictly accorded with the detection kit (both purchased from R&D company) operating instructions. Plasma glucose(FPG) was tested with glucose oxidase method, insulin(FINS) with enzymatic radioimmunoassay (RIA),and glycosylated hemoglobin(HbA1c) level was measured by glycated hemoglobin detector. Insulin resistance index (HOMA-IR) and insulin secretion index (HOMA-HBCI) were used to evaluate the isletβcell's function, HOMA-IR=FBG×FINS/22.5, and HOMA-HBCI=20×FINS/(FBG-3.5).Statistical AnalysisThe data were processed by SPSS16.0 statistical software. Comparison between the two groups with t-test, and comparison between groups with analysis of variance. If the mean variance was not neat, we used the rank sum test.The count data were compared by X2 test. Spearman rank correlation and Pearson correlation were employed for correlation analysis. Statistical significance level was 0.05, and P<0.05 was considered statistically significant.Results1. GLP-1 and DPP-IV levels of gestational diabetes mellitus (GDM) group respectively were (26.35±5.26)pmol/L,(19.57±2.55)ng/ml, normal glucose tolerance (NGT) group were (34.83±5.21)pmol/L,(14.37±3.83)ng/ml, and control (Normal) group were (35.74±4.98)pmol/L,(13.11±4.19)ng/ml。Significantly reduced serum GLP-1 concentration and elevated DPP-IV concentration were found in the women with GDM as compared with NGT group and Normal group, and the differences were statistically significant(P< 0.05); but there were no significant differerces between the latter two groups in the level of GLP-1 and DPP-IV (P>0.05).2. Compared with NGT group and Normal group, obviously insulin resistance and secretion decrease were discovered in GDM women(P<0.05),but the two indices showed no significant differences between NGT group and Normal group(P>0.05).3. Linear regression method was applied to analyze the relationship between GLP-1,DPP-IV and FPG,FINS,HbAlc in GDM patients, results showed that GLP-1 was negatively correlated with FPG,while DPP-IV was positively correlated with FPG (P<0.05), but no obvious correlation was discovered between GLP-1,DPP-IV and other indices(P>0.05).4. The incidence rates of cesarean section, pregnancy complicated with hypertension, polyhydramnios and premature rupture of membrane were significantly higher than NGT group (P<0.05), but no significant differences were discovered between them in oligohydramnios and postpartum hemorrhage (P>0.05).5. In the perinatal infant aspect, the incidence rates of fetal distress and giant infant were obviously higher than NGT group (P<0.05),but low birth weight child and neonatal hypoglycemia with no significant differences between them (P>0.05).Conclusions1. The decreased serum concentration of GLP-1 and hypersecretion of DPP-IV may exist in GDM patients, and it perhaps plays a great part in the pathogenesis of gestational diabetes mellitus.2. The serum level of GLP-1 in GDM patients was negatively correlated with FPG, while the level of DPP-IV was positively correlated with FPG..Regulating the substances which can increase GLP-1 or decrease DPP-IV may have a great effect in lowing blood glucose. |
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