Research Of Correlation Between Serum C-peptide And Carotid Atherosclerosis In Type2Diabetes Mellitus

Objective:In the research, we detected the carotid intima-media thickness(IMT), thecharacteristic of atherosclerosis plaques in patients with type2diabetes mellitus by carotidultrasound, intending to investigate the correlation between serum C-peptide level andcarotid atherosclerosis in type2diabetes mellitus.Methods:From July2011to March2012in department of endocrinology, Affliated Hospital ofTaishan Medical College,94inpatients (51males and43females) with type2diabetesmellitus collected were enrolled. Their age were from49to66years old, with an averageage57.2±3.9years. DM diagnosis is according to1999WHO diagnosis standard of DM.All patients had no secondary diabetes mellitus, type1diabetes mellitus, acute diabeticcomplication, haematological disease, rheumatic immune disease, malignant tumor, recentmajor surgery and injury, serious heart, liver and kidney dysfunction, pregnant andlactating women. All these patients were divided into different groups based on cardtidintima-media thickness and the characteristic of plaques. We gathered all these patientswith age, sex, smoking and drinking, measured height, weight, systolic blood pressure(SBP)and diastolic blood pressure(DBP), calculated body mass index(BMI); tested fasting bloodglucose(FBG), glycosylated hemoglobin(HbA1c), total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C);tested fasting serum C-peptide(FCP) level and postprandial2h serum C-peptide(PCP) levelwith radioimmunoassay. We compared the clinical data and C-peptide level of differentgroups, and then analyzed the correlation between serum C-peptide and carotidatherosclerosis in type2diabetes mellitus.Rusults:1. Comparison of FCP and PCP level with different echo plaques: FCP and PCP level were lower in low echo group, mixed echo group and strong echo group compared withcontrols, difference was statistically significant (P<0.01); there was no significantdifference between low echo group, mixed echo group and strong echo group(P>0.05);there was no significant difference between unstable plaque group and stable plaquegroup(P>0.05).2. Comparison of FCP and PCP level with different intima-media thickness: FCP andPCP level in group of0.9≤IMT<1.0, group of1.0≤IMT<1.1and group of1.1≤IMT<1.2were lower compared with controls, difference was statistically significant (P<0.01); FCPand PCP level in group of1.0≤IMT<1.1and group of1.1≤IMT<1.2were lower comparedwith group of0.9≤IMT<1.0, difference was statistically significant (P<0.01); the differenceof FCP and PCP level between group of1.0≤IMT<1.1and group of1.1≤IMT<1.2was notstatistically significant (P>0.05).3. A negative correlation was found between FCP level and diabetic duration, FBG,HbA1c, TG, LDL-C, SBP(r=-0.316, P=0.009; r=-0.307, P=0.011; r=-0.274, P=0.024;r=-0.289, P=0.017; r=-0.261, P=0.031; r=-0.262, P=0.031); a positive correlation was alsoevident between FCP level and HDL-C(r=0.292，P=0.031); there was no statisticallycorrelation between FCP level and TC, DBP.4. A negative correlation was found between PCP level and diabetic duration, FBG,HbA1c, TG, LDL-C, SBP(r=-0.557, P=0.000; r=-0.381, P=0.001; r=-0.271, P=0.025;r=-0.249, P=0.040; r=-0.238, P=0.049; r=-0.306, P=0.011); a positive correlation was alsoevident between PCP level and HDL-C(r=0.335, P=0.005); there was no statisticallycorrelation between PCP level and TC, DBP.Conclusions:1. Serum C-peptide was reduced in type2diabetics with carotid atherosclerosis,which may play a protective role in the occurrance and development of type2diabeteswith carotid atherosclerosis.2. Further study of C-peptide and the pathogenesis of type2diabetes with carotidatherosclerosis, supplementation of exogenous C-peptide to observe the treatment effect ofcarotid atherosclerosis, have important clinical significance.