Analysis Of HbA1c Level And Islet Cell Function In Newly Diagnosed T2DM Patients In Xining Area

Objective: By analyzing the relationship between different glycosylated hemoglobin（Hb A1c）levels and islet β cell function in newly diagnosed type 2 diabetes mellitus（T2DM）patients in Xining area,to understand the islet function status of newly diagnosed T2 DM patients at different Hb A1 c levels and provide guidance for clinical treatment of newly diagnosed diabetes mellitus patients in Xining area.Methods: The 50 patients with normal glucose tolerance were divided into group A and 270 patients with newly diagnosed T2 DM were divided into three groups according to Hb A1c: group B（n = 90）: Hb A1 c < 7%,group C（n = 99）: 7% ≤ Hb A1 c ≤ 9%,group D（n = 81）: Hb A1 c > 9%.General data such as name,gender,age,body mass index（BMI）,waist circumference（WC）,glycosylated hemoglobin（Hb A1c）,blood pressure（mm Hg）,blood lipid（TG）and blood cholesterol（TC）were collected.Fasting blood glucose,insulin,blood glucose,insulin,homeostasis model assessment of islet β cell secretion index（HOMA-β）,insulin resistance index（HOMA-IR）,insulin sensitivity index（ISI）,insulin proliferation ha an hour after glucose load and blood glucose proliferation ratio(ΔI₃₀/ΔG₃₀),insulin area under curve 60-120 minutes after glucose load and blood glucose area ratio(AUC_{I60-120/G60-120})were used to evaluate islet β cell function and compared between the groups.regression analysis was used to evaluate the correlation between Hb A1 c levels and various indicators of pancreatic β-cell function in newly diagnosed T2 DM patients in Xining.The data were statistically analyzed using SPSS 21.0 software.Results:（1）Comparison of general data between groups: BMI of T2 DM three groups was higher than normal,（BMI ≥ 24 kg/m² was defined as overweight）,BMI of Hb A1 c < 7% group and 7% ≤ Hb A1 c ≤ 9% group was greater than NGT group,（all P < 0.05）,BMI of T2 DM 7% ≤ Hb A1 c ≤ 9% group was greater than Hb A1 c > 9% group（P < 0.05）.WC was greater in all T2 DM groups than in the NGT group(all P < 0.05.,and there was no statistically significant difference between the groups in the other indicators.（2）Comparison of blood glucose and insulin levels at different time points between the groups: FPG and 2h PG were higher in the T2 DM groups than in the NGT group（all P < 0.05）,and gradually increased with the increase of Hb A1 c between the T2 DM groups.FINS was smaller in the Hb A1 c > 9% group than in the first three groups（P < 0.05）,and there was no difference between the other groups.2h INS was greater in the Hb A1 c < 7% group than in the NGT group and less in the Hb A1 c > 9% group than in the NGT group（P < 0.05）,which was not statistically different from the 7% ≤ Hb A1 c ≤ 9% group,and 2h INS decreased with increasing Hb A1 c among the three groups of T2 DM,all of which were statistically different.（3）Comparison of islet β cell function index between the groups showed that ΔI₃₀/ΔG₃₀ and AUC_{I60-120/G60-120} in T2 DM groups were lower than those in NGT group（all P < 0.05）,and gradually decreased with the increase of Hb A1 c level between T2 DM groups.HOMA-β in the NGT group was not different from that in the Hb A1 c < 7% group,greater than 7% ≤ Hb A1 c ≤ 9% group,and Hb A1 c > 9% group（all P < 0.05）,and gradually decreased with increasing Hb A1 c among the T2 DM groups.HOMA-IR was greater in the T2 DM group than in the NGT group,and Hb A1 c < 7% was less than 7% ≤ Hb A1 c ≤ 9%,7% ≤ Hb A1 c ≤ 9% was greater than Hb A1 c > 9%,and there was no statistically significant difference in Hb A1 c < 7% Hb A1 c > 9%.ISI was lower in the 7% ≤ Hb A1 c ≤ 9% group than in the NGT Hb A1 c < 7% group（all P < 0.05）,and there was no statistical difference between the other groups.（4）The results of correlation analysis between Hb A1 c and each clinical index in T2 DM group showed that Hb A1 c was negatively correlated with FINS,2h INS,HOMA-β,ΔI₃₀/ΔG₃₀,and AUC_{I60-120/G60-120},and positively correlated with FPG,2h PG,and ISI.（5）In multiple linear regression,Hb A1 c was used as the dependent variable Y,and 2h PG,2h INS,FPG,and ISI were used as independent variables,which were labeled X₁,X₂,X₃,and X₄,respectively,to obtain the equation Y = 3.325 + 0.176X₁-0.009X₂ + 0.328X₃ + 27.085X₄,and multiple linear regression was performed to introduce the regression equation to obtain the analysis of variance F = 49.660,P < 0.001,and the equation was valid.The standardized regression coefficient values of marker response variables X1,X2,X3 and X4 were 0.300,-0.139,0.290 and 0.186,respectively,indicating that the effects of these four factors on Hb A1 c were 2h PG,FPG,ISI and 2h INS,respectively.Conclusion:（1）For newly diagnosed T2 DM patients with low glycosylated hemoglobin level（Hb A1 c < 7%）,more attention should be paid to the change of 2-hour postprandial blood glucose in clinical practice,so as to early detect the loss of early phase islet β cell function.（2）Basal insulin secretion function of newly diagnosed T2 DM patients in Xining area was significantly affected in the early stage（Hb A1 c < 7%）,and significantly decreased when Hb A1 c > 9%.For newly diagnosed T2 DM patients with Hb A1 c > 7%,clinical treatment should be initiated as early as possible,and patients with Hb A1 c > 9% should be treated with exogenous insulin,thus striving for more opportunities for apoptosis of pancreatic β-cells.（3）For newly diagnosed T2 DM patients in Xining area,controlling Hb A1 c below 9% for the assessment of insulin secretion function and insulin resistance can reduce the interference of glucotoxicity and more accurately assess islet β cell function.