The Value Of The Glycosylated Hemoglobin And Fasting Blood Glucose Detection In Diagnosing Abnormal Glucose Metabolism In Patients With Hyperthyroidism

Objective To investigate the value of hemoglobin A1c(HbA1c)and fasting blood glucose(FPG)in screening diabetes and pre-diabetes in patients with hyperthyroidism,and determine the optimal cut-off point.Methods 508 hyperthyroidism who carried out oral glucose tolerance test were recruited into the study,and HbA1c were measured at the same time.ROC curve was made to determine the optimal cut-off point,positive likelihood ratio and negative likelihood ratio.Results(1)According to the 2010 WHO diagnostic criteria for diabetes,according to blood glucose standard: 69 cases of patients with newly diagnosed diabetes(13.6%),167 cases of IGR(32.9%),of which 6 cases with IFG(3.59% IGT),158 cases(94.61%),3 cases of IFG with IGT(1.80%).NGT was 272 cases(53.5%).According to the HbA1c criteria,18 patients were newly diagnosed with diabetes mellitus(3.5%),181 with IGR(35.6%),and 309 with NGT(60.9%).The positive rate of combined with diabetes was significantly lower than that of OGTT in the diagnosis of hyperthyroidism by HbA1c of 6.5%,P<0.05.(2)The levels of HbA1c?FPG?2h PG in DM group,IGR group and NGT group were reduceded gradually with statistical difference(6.0±0.4,5.5±0.3,5.3±0.2)(P<0.001).(3)According to the ROC curve,5.4% was the optimal cut-off point of HbA1c for diagnosis of IGR,and the specificity was 64.39%,the sensitivity was 55.9%,.5.5%,was the optimal cut-off point of HbA1c for diagnosis of DM,with the sensitivity of 79.71% and the specificity of 73.16%.(4)HbA1c had been recommended by WHO as an indicator of screening and diagnosing diabetes and prediabetes in the general population.In this study,when the cut-off point of HbA1c was 5.4%,the negative predictive value was 55.9% and the positive predictive value of was 77.2% and When the cut-off point of HbA1c was 5.5%,the negative predictive value was 54.3%,and the positive predictive value was 77.8%.When the value of Hb Alc was 5.5%,the number of DM and OGTT diagnoses was the same as that of the combined FPG diagnosis,with 100%.Nc Memar test analysis,HbA1c combined with FPG diagnosis,DM and OGTT diagnostic results of the anastomosis was statistically significant,P<0.001.Hb Alc combined with FPG screening DM is more consistent than single Hb Alc screening.Conclusion HbA1c can reflect the different glucose metabolism in patients with hyperthyroidism correctly,and the optimal cut-off point of HbA1c for screening IGR and DM is 5.4% and 5.5%.HbA1c.The coincidence degree in the diagnosis of DM by the combination of Hb Alc and FPG is higher than that of Hb Alc alone.