The Optimal Cut-off Value Of HbA1c For Screening And Diagnosing Diabetes Mellitus In Xining Region

Objective: The best cut-off value of glycosylated hemoglobin to investigate the screening and diagnosis of diabetes mellitus in Xining region,when the value of HbA1c in the Qinghai area to provide data for the diagnosis of DM,to provide reference for Chinese scholars to improve the relevant data in plateau area.Methods: During the period from January 2015 to October 2016,people at risk of diabetes in Xining area,who get treatment in Department of endocrinology of Affiliated Hospital of Qinghai University were our subjects.To determine the object of study,all the people must be judged through strict accordance with the inclusion criteria and exclusion criteria,a total of 699 cases had been chosen,including 439 cases of male,260 cases of female.All subjects were subjected to the oral glucose tolerance test(OGTT),and glycosylated hemoglobin A1c(HbA1c).Results:(1)With OGTT as the gold standard for the diagnosis of diabetes,during the 699 patients(439 were male,260 were female),the diagnosis of DM are369 cases(52.8%),a total of 148 cases are IGR(21.2%),a total of 182 cases are NGT(26%).(2)Based on OGTT--the "gold standard" of DM diagnostic,through ROC curves can be obtained using the OGTT2 h PG diagnosis of DM is better than HbA1c,and the application of HbA1c in the diagnosis of DM is better than that of FPG: the area under the curve of OGTT2 h PG was 0.999(95%CI: 0.998~1.000);the area under the curve of HbA1c was 0.972(95%CI 0.962~0.983);the area under the curve of FPG: 0.959(95%CI 0.945~0.973).(3)Through the ROC curve,and the application of Youden index(sensitivity + specificity-1)the maximum point to find the optimal cut point of HbA1c for the diagnosis of DM was 6.45%,the cut-off point of the corresponding sensitivity and specificity respectively were 87.3% and 98.5%,the positive predictive value and negative predictive value respectively were 98.5% and87.4%;HbA1c diagnosis of IGR(sugar Pre diabetes)the optimal cut-off value of5.65% points,the corresponding sensitivity and specificity respectively were 58.8%and 75.3%,the positive predictive value and negative predictive value respectivelywere 65.9% and 69.2%.Conclusions:(1)Application of HbA1c diagnosis of DM is better than FPG.(2)HbA1c screening in high-risk patients with diabetes and diagnosis of diabetes and pre diabetes(IGR)and the best cut-off value was 6.45% and 5.65% in Xining region.(3)HbA1c = 6.45% as diagnostic criteria for diabetes is more than using FPG?7.0mmol/ L as the diagnostic criteria of sensitivity,but less than OGTT2 h PG?11.1mmol/L as diagnostic standard of sensitivity.