Vascular Function Monitoring And Effecting Factors In Children/Adolescents With Type 1 Diabetes Mellitus

ObjectiveTo monitor the vascular function of children/adolescents with Type 1 Diabetes(T1D),assess the effects of long-term and short-term glucose fluctuation on vascular function,and explore the effects of different ways of insulin use and blood glucose monitoring on glycemic control and vascular function.MethodsAge,course of disease,Lipids[High Density Lipoprotein(HDL),Cholesterol,Triglycerides(TG),Low Density Lipoprotein(LDL)],Body Mass Index(BMI)Standard deviation[Standard deviation of body mass index of the same age and gender(BMI-SD)],Systolic Blood Pressure(SBP),Glycemic indexes[Standard Deviation of Blood Glucose(SDBG),Largest Amplitude of Glycemic Excursions(LAGE),Postprandial Glucose Excursion(PPGE)],glycosylated hemoglobin(HbA1c),Urinary Albumin Creatinine ratio(ACR)and Flow Mediated Dilation(FMD)were collected in 38 children with T1D,while 15 healthy controls were matched by sex and age,and related data were collected.The basic data of children with T1D and healthy control group were compared by independent sample t test or nonparametric test.According to well?controlling criterion as HbA1c<7%,they were divided into healthy controls,the well-controlled group(HbAlc<7%)and the poorly-controlled group(HbA1c?7%).By ANOVA test,the differences in FMD and ACR of 3 groups were analyzed.The correlation factors of FMD and ACR were analyzed using Pearson or Spearman methods.The influencing factors of FMD and ACR were analyzed by multiple regression analysis.With the independent sample T test,the different effects of insulin use and blood glucose monitoring methods on blood glucose fluctuation and vascular function were analyzedResults1.FMD in the healthy control group was little higher than that in the children with T1D(18.5±5.7%VS 15.4±10.3%),but there was no statistical significance(P>0.05)ACR was lower than that of T1D(8.58±3.92 VS 17.99±8.71mg/g),with statistical significance(P<0.01)2.ACR of the healthy control group was lower than that of the well-controlled T1D group and the poorly-controlled T1D group(8,58±3.92 VS 16.99±9.10mg/g;8.58±3.92 VS 18.45±8.66mg/g,P<0.05).However,there was no statistical difference in FMD(P>0.05).In T1D group,there were no significant difference in the indicators of vascular function(FMD and ACR in the well-controlled group was similar with that in the poorly-controlled group,P=0.636,0.27,respectively),whether HbA1c was met to standard or not.3.Pearson and Spearman correlation analysis:FMD was negatively correlated with BMI-SD,SDBG and LAGE,and their r values were-0.351?-0.568?-0.464,respectively(P<0.05).ACR was negatively correlated with age,course,and their r values were-0.613,-0.491,(P<0.05),while ACR was positively correlated with HbA1c-SD(r=0.486,P=0.002)4.(1)FMD of multiple regression analysis:SDBG,BMI-SD had statistical significance(P<0.05),and the two factors of standardized coefficient were-0.384?-0.396,respectively;FMD was mainly decided by the SDBG,BMI-SD.if other factors' influences were the same,the higher SDBG,the bigger BMI-SD would lead to the worse FMD,which meant the worse vascular endothelial function.(2)ACR regression analysis:age,HbA1c-SD was statistically significant(P<0.05),and their standardized coefficients were-0.491 and 0.353.In other words,at the same age,the higher fluctuation of HbA1c would lead to the higher ACR,which meant the worse renal microvascular function5.According to the different ways of insulin use and blood glucose monitoring,it was divided into the insulin pump or CGMs group and the traditional treatment group(4 times daily subcutaneous insulin injection and multiple fingertip blood glucose monitoring).Comparison of insulin pump or CGMs group and traditional treatment group:SDBG(2.6±0.8 VS 3.5±1.1 mmol/L),LAGE(6.4±3.6 VS 9.6±4.3 mmol/L),PPGE(2.2±1.0 VS 3.8±1.5 mmol/L),FMD(19.4±8.9%VS 12.5±10.4%),in other words,SDBG,LAGE and PPGE were smaller and FMD was higher in the insulin pump or CGMs group,and the t values were-2.663,-2.410,-3.946 and 2.134,respectively(P<0.05).There were no significant differences in HbA1c-SD and ACR between the insulin pump or CGMs group and the traditional treatment group(P>0.05)Conclusions1.In this study,the renal microvascular function of children with T1D are worse than those of healthy children.It cannot predict the vascular function of children with T1D according to HbA1c level.2.Glucose fluctuation and obesity can affect the vascular function of T1D children,and short-term blood glucose fluctuation and obesity was related to FMD in large blood vessels.The fluctuation of HbA1c had a stronger correlation with renal microvascular complications,which is a risk factor of microvascular complications.In clinical practice,besides the level of HbAlc,more attention should be paid to the harm of blood glucose fluctuations to blood vessels3.Using CGMs or insulin pump can better manage blood glucose,reduce blood glucose fluctuation,be more meaning helpful for blood glucose control,so as to improve the great vascular function.However,no protective effect on microvascular function was found.