Cutpoint and clinical significance of HbA1C for diabetes diagnosis in a cross-sectional study / 中华内分泌代谢杂志

ABSTRACT

Objective To compare the difference of cutpoint and clinical significance of HbA1C for the diagnosis of abnormal glucose metabolism in two population groups with different ages.Methods According to oral glucose tolerance test(OGTT),the cutpoint and clinical significance of HbA1C for the diagnosis of type 2 diabetes and impaired glucose regulation(IGR)were investigated in the two population groups.Results The mean HbA1C of 1 064 young subjects in an academy and 1 671 aged subjects in a community were 5.31% ±0.41% and 5.79% ±0.71%,respectively.The cutpoints of HbA1C for diagnosis of diabetes were 5.7%(specificity 86.7%,sensitivity 66.7%)and 5.9%(specificity 73.8%,sensitivity 80.1%)in the two population groups,and 5.6% for diagnosis of IGR (specificity 82.8%,sensitivity 55.8%)and 5.7%(specificity 60.9%,sensitivity 64.3%),respectively.87.8%,78.7%,and 38.5% were diagnosed diabetes by current OGTT criteria at HbA1C levels of ≥5.7%,≥5.9%,and≥6.5%,IGR being 61.6%,39.6%,and 4.1%,and normal glucose tolerance being 24.4%,10.0%,and 0.4%.Conclusion The cutpoints of HbA1C for diagnosis of diabetes and IGR are different in populations with different ages and HbA1C levels.As one of diagnostic criteria for diabetes,HbA1C 6.5% with relatively higher specificity and lower sensitivity must be combined with fasting blood glucose,random blood glucose,and OGTT.