The Function Changes Of Pancreatic Islets Beta-cell,Adrenal Cortex And Sympatho-adrenomedullary Before And After Treatment In Patients With Type2Diabetes

Objective: Diabetes mellitus become as a significant, chronic andnoninfectious disease throughout the world. Its incidence is increasing rapidly,especially in developing countries. Both inadequate insulin and insulinresistance are the main causes of the disease. But much attention has beenattached to counter-regulatory hormones such as glucocorticoid,catecholamine in the development and progress of diabetes. Results of manydomestic and foreign researches showed that there are hypothalamus-pituitary-adrenal (HPA) axis and sympatho-adrenomedullary functiondisorder even in the early stage of type2diabetes, namely they are bothoveractive under diabetic condition and level of relative counter-regulatoryhormones rise markedly. Although the most scholars consider that level of allkinds of catecholamine rise in patients with type2diabetes, there are stillcontroversies about it. Hence, more researches on HPA axis and sympatho-adrenomedullary system during diabetes development, progress and treatmentare needed. In this study we compared changes of beta-cell function index,24hours urine free cortisol(UFC) and catecholamine metabolism product levelbefore and after insulin treatment in patients with type2diabetes in order toevaluate the effects of insulin treatment on pancreatic islets, adrenal cortex andsympatho-adrenomedullary.Methods：In this study, we randomly recruited30patients with type2diabetes (20male cases,10female cases). The span of year is from28yr to63yr (average:46.7±10.4yr).The span of body mass index is from19.7Kg/cm2to33.9Kg/cm2(average:26.39±3.12Kg/cm2). All patients werenewly diagnosed as diabetes in accordance with of diabetes standard based onWHO(1999), which were with fasting plasma glucose(FPG) over12mmol/l and not treated. Exclusion standard: the patients were excluded from this studyif they were in one or more of following situations: infection, hepatic andkidney injury, heart disease, hypertension, type1diabetes, ketosis, diabeticketoacidosis and thyroid dysfunction, or being under treatment with medicines.All candidates were received insulin intensive therapy (continuoussubcutaneous insulin infusion or multiple subcutaneous insulin injections).Then, level of the following items were tested and compared before and aftertreatment:fasting plasma glucose (FPG),fasting C-peptide (FCp),postprandial2h plasma glucose(P2hPG),postprandial2h C-peptide (P2hCp),24h urine freecortisol (UFC),24h urine normetanephrine (NM),24h urine metanephrine(MN)and beta-cell function index(Cp/G) using formula Cp/G=(P2hCp-FCp)/(P2hPG-FPG). All changes of above indexes were analyzed whether itwas statistically significant or not. The level of plasma glucose, C-peptide,24hUFC,24h urine NM and MN were measured by glucose oxidase method,electrochemistry luminescence, high performance liquid chromatography andenzymelinked immunosorbent assay respectively.Statistical analysis was performed by using SPSS13.0software package.P<0.05was considered statistically significant. The normal distribution datawas described by Mean±SD and skewed distribution data was described by M(P₂₅, P₇₅).The normal distribution and homogeneity variance data was anal-yzed by paired-samples T test, otherwise using nonparametric test (WilcoxonSigned Ranks Test).Results：1The patients with type2diabetes had lower level of FPG and P2hPG andhigher beta-cell function index (Cp/G) after insulin treatment (P<0.01).The average of FPG and P2hPG are12.3±2.7and21.5±4.7mmol/lrespect tively, and M(P₂₅,P₇₅)of Cp/G is0.11(0.06,0.17)before treatment.The average of FPG and P2hPG are6.2±1.3and12.3±3.7mmol/l respectively,and M(P₂₅,P₇₅)of Cp/G is0.23(0.12,0.32)after treatment.2The patients with type2diabetes significantly decreased24h UFC after in-sulin treatment (P<0.05). M(P₂₅,P₇₅)of24h UFC is45.88(25.07,59.76)ug/24h before treatment, and29.70(17.54,49.54)ug/24h after treatment.3Compared with before treatment, the level of24h urine NM of patientswith type2diabetes has significantly decreased after insulin treatment (P<0.05).M(P₂₅,P₇₅)of24h urine NM is267.44(203.10,386.50)ug/24h beforetreatment, and198.01(151.40,402.07)ug/24h after treatment.4There is no significant difference in the level of24h urine MN betweenbefore and after treatment (P>0.05).M(P₂₅,P₇₅)of24h urine MN is80.43(56.84,127.05)ug/24h beforetreatment, and88.88(60.76,113.83)ug/24h after treatment.Conclusion:1Insulin treatment could improve pancreatic beta-cell function of patientswith type2diabetes.2Insulin treatment could inhabit HPA axis hyperactivity under diabeticcondition.3Insulin treatment could inhabit sympathetic system hyperactivity underdiabetic condition by reducing norepinephrine level.