Abstract
Objective To investigate the cut - off points of glycosylated hemoglobin (HbA glucose (FPG)for early diagnosis of diabetes mellitus. Methods The subjects enrolled in this study were 766 consecutive outpatients and inpatients of Kailuan General Hospital Affiliated to North China University of Science and Technology who underwent measurement of HbA1c ,FPG and oral glucose tolerance test (OGTT)between January 2012 and April 2016. We used HA - 8160 Automatic Glycosylated Hemoglobin Analyzer made in Japan with high pressure liquid chromatography to determine HbA1c ,and HITACHI 7600 Automatic Biochemical Analyzer with hexokinase method to determine FPG. We divided the patients into diabetic group 〔2 - hour postprandial blood glucose (2 hPG)≥11. 1 mmol/ L,n = 628〕and non - diabetic group (2 hPG< 11. 1 mmol/ L,n = 138)based on the Definition,Diagnosis and Classification of Diabetes Mellitus and Its Complications 1c )and fasting plasma revised by WHO in 1999. We drew the receiver operating characteristic (ROC)curves of HbA 1c and FPG,and investigated the optimal cut - off points of them for the diagnosis of diabetes mellitus with analyzing the sensitivity,specificity,positive predictive value,negative predictive value,positive and negative likelihood ratios,Youden's index and Kappa value. Results The largest area under curve (AUC)of HbA 1c's ROC curve in the diagnosis of diabetes mellitus was 0. 918 〔95% CI (0. 895,0. 942),P< 0. 001〕,the cut - off point was 6. 55%,with a sensitivity of 90. 1%,specificity of 75. 4%,positive predictive value of 90. 1%,negative predictive value of 75. 4%,positive likelihood ratio of 3. 7,negative likelihood ratio of 0. 1,Youden's index was 0. 66 and Kappa value of 0. 63. The largest AUC of FPG' s ROC curve in the diagnosis of diabetes mellitus was 0. 901〔95% CI (0. 877,0. 926),P < 0. 001〕,the cut - off point was 6. 23 mmol/ L,with a sensitivity of 85. 0%,specificity of 81. 9%,positive predictive value of 84. 9%,negative predictive value of 81. 9%,positive likelihood ratio of 4. 7,negative likelihood ratio of 0. 2,Youden's index was 0. 67 and Kappa value of 0. 65. The cut off points of HbA 1c (6. 55%)and FPG (6. 23 mmol/ L)for the combined diagnosis of diabetes mellitus had a sensitivity of 76. 6%,specificity of 95. 5%,positive predictive value of 65. 5%,negative predictive value of 98. 3%,positive likelihood ratio of 17. 0,negative likelihood ratio of 0. 3,Youden's index was 0. 72 and Kappa value of 0. 70. Conclusion HbA 1c (6. 55%)combined with FPG (6. 23 mmol/ L)can be one of the methods for early diagnosis of diabetes mellitus,for it has good specificity. Moreover,it has higher Youden's index and Kappa value than HbA1c (6. 55%)or FPG (6. 23 mmol/ L)used alone as the early diagnosis method of diabetes mellitus.关键词
糖尿病/血红蛋白A,糖基化/空腹血糖/诊断/截点Key words
Diabetes mellitus/Hemoglobin A/glycosylated/Fasting plasma glucose/Diagnosis/Cut - off point分类
医药卫生
