HbA_(1c)诊断2型糖尿病特性观察及在空腹血糖正常人群中的分布特征研究

目的观察糖化血红蛋白(HbA1c)诊断2型糖尿病(T2DM)的特点及其在空腹血糖(FPG)正常者中的分布情况。方法同时测定729例FPG正常者尿酸(UA)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C);用免疫抑制比浊法测定247例接受口服葡萄糖耐量试验(OGTT)者(包括T2DM 164例、糖耐量受损41例、空腹血糖受损18例、糖耐量正常者24例)的HbA1c,以OGTT和临床诊断结果作为标准,绘制HbA1c和FPG的受试者工作特征(ROC)曲线,确定HbA1c诊断T2DM的切点,通过对比分析观察不同性别及同性别不同年龄组中HbA1c的分布情况。结果免疫抑制比浊法测定HbA1c诊断T2DM的切点为6.36%,诊断灵敏度为86.50%、特异性为90.60%、阳性预测值为94.63%、阴性预测值为76.50%、曲线下面积为0.944[95%可信区间(CI):0.917~0.971],FPG7.0 mmol/L时诊断糖尿病的灵敏度为85.90%、特异性为93.80%、曲线下的面积为0.957[95%CI:0.932~0.981]。FPG正常者中女性HbA1c、HDL-C水平明显高于男性(P=0.000),男性血红蛋白(Hb)、FPG、UA、TG水平高于女性(P值分别为0.000、0.020、0.000、0.000)。随着年龄的增加,男、女性HbA1c、FPG、TC和LDL-C均有增高的趋势;特别是在60岁以后,女性HbA1c升高更高明显;但HDL-C在男性中有上升的趋势,在女性中有下降的趋势。结论免疫抑制比浊法测定HbA1c诊断T2DM的切点为6.36%,随着年龄的增加要定期测定HbA1c,以达到预防糖尿病的目的。

Observation on the characteristic of HbA1c for diagnosing type 2 diabetes mellitus and research on the distribution characteristic in population with normal fasting plasma glucose

Objective To observe the characteristic of glycosylated hemoglobin A1 c （HbA1 c ）for diagnosing type 2 diabetes mellitus （T2DM）and its distribution characteristic in population with normal fasting plasma glucose（FPG）. Methods A total of 729 subjects with normal FPG were enrolled,and uric acid （UA）,triglyceride （TG）,total cholesterol（TC）,high-density lipoprotein cholesterol（HDL-C）and low-density lipoprotein cholesterol （LDL-C）were determined.Oral glucose tolerance test（OGTT）was administered to 247 patients,including 1 64 cases with T2DM,41 cases with impaired glucose tolerance,1 8 cases with impaired fasting glucose and 24 cases with normal glucose tolerance.HbA1 c was determined by turbidimetric inhibition immunoassay,and the receiver operating characteristic （ROC）curve was used to determine the cut-off point of HbA1c and FPG for diagnosing T2DMaccording to the results of OGTT and clinical diagnosis.The distribution characteristics of HbA1 c with different sex and with different age in same sex were analyzed and observed comparatively.Results The cut-off point of HbA1 c for the diagnosis of T2DM was 6.36% with a sensitivity and specificity of 86.50%and 90.60%respectively,the positive predictive value and negative predictive value were 94.63% and 76.50% respectively,and the area under ROC curve was 0.944 [95% confidence interval （CI）：0.91 7-0.971 ].The area under ROC curve of FPG was 0.957 （95% CI：0.932-0.981 ）,the sensitivity and specificity were 85.90%and 93.80%when FPG〉7.0 mmol/L for the diagnosis of T2DM.The HbA1c and HDL-C in females with normal FPG were significantly higher than those in males with normal FPG （P=0.000）.Hemoglobin （Hb）,FPG,UA and TG in males were higher than those in females （P=0.000,0.020,0.000 and 0.000）.HbA1 c , FPG,TC and LDL-C were positively correlated with age.After 60 years old,HbA1 c in females increased significantly, there was increasing trend of HDL-C in males,and there was decreasing tread of HDL-C in females.Conclusions The＆amp;nbsp;cut-off point of HbA1c for diagnosing T2DM is 6.36% by turbidimetric inhibition immunoassay.In order to avoid diabetes mellitus,elder people should monitor HbA1 c termly.