糖化血红蛋白在糖尿病诊断中的临床意义

目的通过糖化血红蛋白（HbA1c）水平的检测,探讨其在糖尿病诊断中的意义。方法选取2009年在我院集体健康体检的志愿者2986例（除外已经诊断糖尿病者和其他影响HbA1c检测结果因素者）,全部检查HbAlc及空腹血糖,HbA1c≥6.5%的318例和空腹血糖（FPG）≥6.1 mmol/L的616例（其中FPG≥7.0 mmol/L者262例）,择日再行血糖水平检测或75%糖耐量试验（OGTT）,根据两次检测结果诊断或排除糖尿病。结果进一步检测HbAlc≥6.5%组诊断糖尿病276例,FPG≥6.1 mmol/L组诊断糖尿病311例（其中FPG≥7.0 mmol/L组216例）。以HbA1c≥6.5%为切点诊断糖尿病的敏感性为88.7%,特异性为98.4%;FPG≥7.0 mmol/L为切点诊断糖尿病的敏感性为69.5%,特异性为98.3%;以HbA1c≥6.5%为切点诊断糖尿病的漏诊率（11.3%）,明显低于以FPG≥7.0 mmol/L为切点诊断糖尿病的漏诊率（30.5%）。结论 HbA1c水平可以作为糖尿病诊断的参考指标之一,或提供进一步检查诊断糖尿病的依据。     

糖化血红蛋白对糖尿病的诊断价值分析

目的探讨糖化血红蛋白(HbA1c)对糖尿病(DM)诊断的临床价值。方法以143例健康人、82例空腹血糖受损(IFG)患者和340例DM患者进行口服糖耐量试验(OGTT),葡萄糖氧化酶电极法测定血糖,免疫透射比浊法测定HbA1c,对结果进行分析。结果从健康组、IFG组到DM组,HbA1c水平逐渐增高,各组间比较差异均有统计学意义(P<0.05),以HbA1c≥6.5%或HbA1c≥7.0%作为DM诊断临界值,其诊断灵敏度分别为99.18%和97.33%,诊断特异度分别为94.45%和99.97%,均优于以空腹血糖(FPG)大于或等于7 mmol/L作为诊断临界值的诊断灵敏度(76.43%)和诊断特异度(89.82%)。结论 HbA1c具有比FPG更高的DM诊断灵敏度和诊断特异度;比OGTT更为简便快速,有利于DM的早期诊断,适合作为DM诊断指标而广泛应用。     

糖化血红蛋白对糖尿病的诊断价值

摘要：目的：探讨糖化血红蛋白（HbA1c）在糖尿病(DM)诊断中的应用价值。 方法：随机选择DM初筛患者535例,均行口服葡萄糖耐量试验（OGTT）,用高效液相色谱法检测HbA1c水平。根据OGTT结果把受试者分为糖耐量正常（NGT）组、血糖调节受损(IGR)组和糖尿病(DM)组,NGT组和IGR组并称为非糖尿病组(non-DM)。用ROC曲线分析HbA1c、空腹血糖（FPG）诊断DM及IGR的能力。 结果：DM组患者、FPG、餐后2 h血糖（2h PG）及HbA1c均显著高于其他组(P均＜0.01);上述指标IGR组亦显著高于NGT组(P均＜0.01)。DM组男性患者显著多于女性(P＜0.01)。HbA1c 的cut off值为6.1%时,诊断DM的ROC曲线下面积（AUC^ROC）为0.849,敏感性为79.1%,特异性为78.4%,与7.0 mmol/L FPG的诊断能力无显著性差异（P>0.05）。2者联合应用显著提高诊断能力,AUC^ROC=0.885,敏感性为75.0%,特异性为88.0%。以HbA1c 5.7%为cut-off值,诊断IGR（AUCV=0.66）能力显著低于FPG（AUC^ROC=0.787）,P<0.01。 结论:HbA1c的cut off值为6.1%时可用于诊断DM,与7.0 mmol/L FPG 联合应用可增加诊断DM的能力,但5.7% HbA1c对IGR的筛查能力较弱,不及5.6 mmol/L FPG。     

2型糖尿病及其高危人群筛查方法的探讨分析

目的探讨2型糖尿病(T2DM)及其高危人群筛查适宜而有效的方法。方法选择首钢四个社区的16 056例T2DM普查人群,同时测定空腹血糖(FPG)、口服葡萄糖耐量试验(OGTT)后2 h血糖值(2 h PG)及糖化血红蛋白(Hb A1c),筛查T2DM患者及高危人群。结果 (1)以WHO(1999年)糖尿病诊断标准FPG≥7.0 mmol/L,2 h PG≥11.1 mmol/L,筛出T2DM患者2 011例(12.52%),T2DM高危人群4 334例(26.99%)。(2)按2010年ADA的糖尿病诊断标准筛查T2DM患者:单检测Hb A1c≥6.5%灵敏度为53.41%,漏诊46.59%;单检测FPG≥7.0 mmol/L灵敏度为49.98%,漏诊率50.02%。糖尿病高危人群:Hb A1c≥6.0%或FPG≥6.0 mmol/L灵敏度为69.4%。(3)应用受试者工作特征(ROC)曲线进行统计分析,与OGTT诊断糖尿病相关的FPG最佳切点为6.1 mmol/L,灵敏度和特异度分别为75.5%和90.3%;Hb A1c最佳切点为6.2%,灵敏度和特异度分别为71.4%和84.5%。与OGTT诊断T2DM及高危人群相关的FPG最佳切点为5.7 mmol/L,灵敏度和特异度分别为62%和87.2%,Hb A1c最佳切点为6.0 mmol/L,灵敏度和特异度分别为57.3%和77.4%。(4)若采用联合筛查T2DM以FPG≥6.1 mmol/L或Hb A1c≥6.2%作为标准,灵敏度可达到85.3%,同时有较好的特异度78.9%;以FPG≥5.6 mmol/L或Hb A1c≥6.1%联合筛查T2DM及高危人群作为标准,灵敏度74.4%,特异度71.5%。结论 Hb A1c与FPG联合测定是一种筛查诊断T2DM及糖尿病高危人群方便而有效的方法,建议对5.6 mmol/L≤FPG≤7 mmol/L或Hb A1c≥6.1%的人群应行OGTT,以降低糖尿病的漏诊率。     

空腹血葡萄糖及糖化血红蛋白检测在2型糖尿病诊断中的应用比较

目的:比较空腹血葡萄糖(FPG)和糖化血红蛋白(HbA1c)在2型糖尿病(2DM)诊断中的意义。方法:对188例未诊断为2DM的对象同时检测FPG和HbA1c。分别按1999年世界卫生组织(WHO)诊断糖尿病标准(FPG≥7.0 mmol/L)和美国糖尿病协会(ADA)新标准(HbA1c≥6.5%),对研究对象分别进行分组(2DM和非2DM组),比较2个检测指标在诊断2DM中的差异。以FPG为诊断2DM的金标准,计算HbA1c诊断2DM的灵敏度、特异度、预测值、似然比等诊断性能。结果:FPG均值在2种标准诊断的2DM患者之间差异有统计学意义(P0.05)。HbA1c均值在2种标准诊断的2DM患者间差异无统计学意义(P>0.05),在2种标准诊断的非2DM患者间差异有统计学意义(P<0.05)。HbA1c≥6.5%诊断糖尿病的灵敏度(S)为100%,特异度(Sp)为93%,阴性似然比(-LR)为0.00和阳性似然比(+LR)为14.29。结论:HbA1c诊断糖尿病有较高的诊断灵敏度和特异度。     

云南5家三甲医院老年2型糖尿病患者血糖控制现状及影响因素

目的了解云南三甲医院老年2型糖尿病（T2DM）患者糖化血红蛋白（HbA1c）达标现状及其影响因素。 方法于2015年10月至2016月5月,选取云南5家三甲医院老年T2DM患者151例作为研究对象,进行人口学信息、体质量指数（BMI）、血糖、血压的数据统计,评估血糖控制情况,分析其影响因素。采用单因素方差分析比较不同年龄阶段组间空腹血糖（FPG）、餐后2 h血糖（2 h PG）、糖化血红蛋白（HbA1c）的差异,采用t检验比较不同文化程度组之间、不同BMI组之间、不同糖尿病病程组之间、不同血压组之间FPG、2 h PG及HbA1c的差异。 结果年龄（73.4±7.4）岁,病程（11.4±8.0）年,HbA1c（8.8±2.2）%,HbA1c<7.0%的患者29例（19.2%,29/151）,BMI（24.3±3.6）kg/m²,BMI<24 kg/m²的患者占50.3%（76/151）,FPG<7.0 mmol/L占33.1%（50/151）,2 h PG<10.0 mmol/L占23.8%（36/151）;按年龄60~69岁、70~79岁、≥80岁分组,HbA1c组间比较［（8.1±2.0）% vs （8.9±1.8）% vs （9.2±2.5）%］,差异具有统计学意义（F=3.711,P=0.027）、2 h PG组间比较［（11.6±3.1）mmol/L vs （14.9±5.0）mmol/L vs （14.4±5.7）mmol/L］,差异具有统计学意义（F=5.829,P=0.004）,FPG组间比较［（7.7±2.6）mmol/L vs （9.5±3.6）mmol/L vs （9.3±3.4）mmol/L］,差异无统计学意义（F=2.948,P=0.056）;初中及以下组及高中及以上组间,HbA1c组间比较［（9.0±2.2）% vs （8.2±2.0）%］,差异具有统计学意义（t=2.269,P=0.025）,FPG、2 h PG组间比较,差异无统计学意义（P>0.05）;按照BMI<24 kg/m²、≥24 kg/m²分组,HbA1c、FPG、2 h PG组间差异均无统计学意义（P>0.05）;按照血压是否达标,HbA1c、FPG、2 h PG组间差异均无统计学意义（P>0.05）。按照糖尿病病程<10年、≥10年分组,HbA1c、FPG、2 h PG组间差异均无统计学意义（P>0.05）。 结论云南5家三甲医院老年T2DM患者血糖控制与年龄、文化程度有关,随着年龄增加血糖控制较差,文化程度越高,血糖控制越好。BMI、血压、糖尿病病程对血糖控制影响不明显。     

糖尿病的两种空腹血糖诊断标准对比分析

目的探讨糖尿病(DM)新诊断标准中以空腹血糖(FPG)≥7.0 mmol/L(≥1.26 g/L)取代FPG≥7.8mmol/L(≥1.40 g/L)这一变动是否符合本地区临床应用。方法对我院内分泌门诊438例检查血糖的患者用口服75 g葡萄糖耐量试验(OGTT)确诊后,利用2种不同的诊断标准进行对比分析。结果共检出DM患者159例,其中男83例,女76例,利用受试者工作特征(ROC)曲线对FPG≥7.8 mmol/L和FPG≥7.0 mmol/L诊断的特异性和敏感性进行分析,FPG≥7.8 mmol/L的敏感性和特异性分别为56%和99%;而FPG≥7.0 mmol/L的敏感性和特异性分别为68%和97%。结论FPG≥7.0 mmol/L因其特异性达97%,而敏感性又高于FPG≥7.8mmol/L,适合于本地区临床应用。     

糖化血红蛋白诊断糖尿病的切点研究

目的 探讨糖化血红蛋白(HbAlc)用于诊断糖尿病的切点.方法 对为明确DM诊断而初次就诊的高危人群739例进行口服葡萄糖耐量试验(OGTT),测定其空腹血糖(FPG)和服用75 g葡萄糖2h后血糖(2 h PG),同时测定HbAlc,根据WHO(1999年)糖代谢状态分类标准进行分组,研究人群糖耐量正常(NGT) 61例,空腹血糖受损(IFG) 46例,糖耐量减低(IGT) 84例,糖调节受损(IGR) 130例,糖尿病(DM) 548例,通过受试者工作特征曲线(ROC曲线)分析,确定HbAlc用于诊断糖尿病的切点.结果 NGT组的HbA1c为(5.7±0.6)％,DM组为(9.8±3.0)％,两者比较差异有统计学意义(t=10.7,P＜0.01);如以FPG≥7.0 mmol/L,或以2 hPG≥11.1 mmol/L,或以FPG≥7.0 mmol/L且2 hPG≥11.1mmol/L,或以FPG≥7.0 mmol/L或2 hPG≥11.1 mmol/L作为诊断糖尿病的标准,HbAlc切点均为6.5％,曲线下面积(AUC)分别为0.981,0.980,0.990和0.973.结论 高危人群糖尿病诊断的HbAlc切点为6.5％,HbAlc不适用于糖调节受损的诊断.     

2型糖尿病患者血液中糖化血红蛋白与空腹血糖的关系

目的研究2型糖尿病(T2DM)患者血液中糖化血红蛋白(HbA1c)水平与空腹血糖的关系。方法选取按世界卫生组织诊断标准诊断的糖尿病患者共200例,采用美国PRIMUSHPLC全自动分析仪检测HbA1c,采用日立7600-20全自动分析仪检测空腹血糖(FPG),取HbA1c=10%,HbA1c<10%为A组,HbA1c≥10%为B组,对比研究两组患者HbA1c水平与FPG的关系。结果 B组HbA1c值(14.7±2.3)%比A组HbA1c值(7.6±1.5)%明显高,差异有统计学意义(P<0.05);B组患者FPG(13.58±3.74)mmol/L比A组FPG(9.24±2.08)mmol/L明显高。结论检测血液中HbA1c对糖尿病患者诊断及治疗具有临床意义,是评价血糖控制方案的金标准。     

胶乳凝集法测定糖化血红蛋白及其在2型糖尿病初诊中的应用

目的探讨胶乳凝集法测定糖化血红蛋白(HbA1c)及其在2型糖尿病(T2DM)初诊中的应用价值。方法选择以往未诊断过糖尿病(DM)和进行相应治疗的志愿者882例,受检者10h内无热量摄入,测定HbA1c、空腹血糖(FPG),餐后2h血糖(2hPG)和行口服葡萄糖耐量试验(OGTT)。结果 218例T2DM患者HbA1c显著高于空腹血糖受损(IFG)、糖耐量受损(IGT)及血糖试验正常(NGT)者(P<0.01);用ROC曲线法得到HbA1c临床诊断界值为6.4%,ROC曲线下面积为0.886,采用HbA1c≥6.4%判断T2DM时,其敏感性为77.5%,特异性为95.0%;以HbA1c≥6.4%检出2hPG≥11.1mmol/L的敏感率为77.0%,漏诊率为23.0%。结论 HbA1c诊断敏感性和诊断性能优于FPG,胶乳凝集法测定HbA1c稳定性好、精确度高,能进行自动分析,可取代FPG用于临床DM筛查和初诊。     

HbA1c对糖调节受损和2型糖尿病的诊断价值

摘要：目的：评估糖化血红蛋白（HbA1c）不同cut off值诊断2型糖尿病（T2DM）的效能,初步探讨美国糖尿病协会（ADA）推荐的HbA1c诊断T2DM及T2DM前期标准对中国人的适用性。 方法：招募接受口服葡萄糖耐量（OGTT）试验且试验前未诊治为T2DM的志愿者338例,用高效液相色谱法检测HbA1c;以WHO标准诊断糖调节受损（IGR）、糖耐量正常和T2DM;用受试者工作特征（ROC）曲线分析不同 cut off值HbA1c诊断IGR和T2DM的效能。 结果：HbA1c在诊断T2DM时,ROC曲线下面积（AUC^ROC）为0.954,最佳cut off值为6.0%,敏感性为92.5%,特异性为86.0%;当HbA1c为6.5%时,敏感性为64.8%,特异性为96.7%;当HbA1c为5.6%时,诊断T2DM阴性预测值为100.0%;HbA1c诊断IGR的AUC^ROC为0.653。 结论: HbA1c用于IGR的诊断效能不高;HbA1c诊断T2DM最佳cut off值为6.0%,此界值诊断敏感性较FPG高,但特异性较差;ADA推荐用于T2DM诊断的cut off值6.5%主要考虑到诊断的特异性,该诊断标准适用于中国人群。     

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。     

探讨糖化清蛋白在糖尿病中的诊断价值及诊断切点

目的评估糖化清蛋白(GA)在糖尿病中的诊断价值及诊断切点,比较GA、糖化血红蛋白(HbA1c)、空腹血糖(FPG)及餐后2h血糖(2hPG)对糖尿病的诊断效能。方法选取470例南京医科大学第一附属医院门诊就诊的疑似糖尿病患者,排除严重肝肾疾病者,检测口服葡萄糖耐量试验(OGTT)、GA、HbA1c。采用SPSS21.0软件进行统计,采用ROC曲线分析各指标对糖尿病的诊断价值并探讨诊断切点。结果 GA对于血糖调节受损(IGR)诊断的ROC曲线下面积为0.693,与HbA1c(0.692)相近;而以最佳截断点14.57%作为诊断切点,GA对IGR诊断的敏感度和特异度分别为0.79和0.55;GA对于糖尿病诊断的ROC曲线下面积为0.911(低于2hPG的0.994和HbA1c的0.948),而以最佳截断点17.50%作为诊断切点,其敏感度和特异度分别为0.89和0.83,其敏感度略高于HbA1c(0.85)。结论 GA对于IGR诊断有一定价值,对于糖尿病诊断有较高价值,可作为2hPG和HbA1c的有效补充。     

How valid is fasting plasma glucose as a parameter of glycemic control in non-insulin-using patients with type 2 diabetes?

OBJECTIVE: To assess the value of fasting blood glucose as a parameter for glycemic control in type 2 diabetic patients not using insulin. RESEARCH DESIGN AND METHODS: In 1,020 type 2 diabetic patients treated with diet or oral hypoglycemic agents (OHAs), measurements of fasting plasma glucose (FPG) and HbA1c were taken. In 617 patients, the measurement could be repeated after 3 months. Cross-sectional correlation coefficients were calculated for the association between HbA1c and FPG. Receiver-operating characteristic (ROC)-curve analyses were applied to examine the performance of FPG as a diagnostic test for HbA1c. Longitudinally, the change in FPG was compared with the change in HbA1c, with both correlation measures and ROC curve analyses. RESULTS: Correlation coefficients between HbA1c and FPG and between FPG change and HbA1c change were 0.77 and 0.65, respectively. ROC curve analysis showed that HbA1c is difficult to predict from FPG values: 66% of the patients with good HbA1c (< 7.0%) were identified as such by FPG values < 7.8 mmol/l. As a test for HbA1c change, FPG change performed moderately: the highest combined values of sensitivity and specificity (87.7 and 57%, respectively) were reached at a cutoff point of zero in the range of FPG change values. CONCLUSIONS: FPG and HbA1c values that do not correspond are not rare in type 2 diabetic patients on diet or OHA treatment. HbA1c is difficult to predict from FPG values, and even more difficult is the prediction of HbA1c changes from FPG changes.     

糖化血红蛋白联合空腹血糖筛查2型糖尿病高危人群的临床意义

目的了解糖化血红蛋白(HbA1c)筛查糖尿病和糖代谢受损的敏感性并与空腹血糖(FBG)进行比较。方法对400例无糖尿病病史的糖尿病高危人群同时检测FBG和HbA1c,据空腹血糖水平分为三组:A1组:FBG<6.1 mmol/L,计336例,A2组:FBG 6.1-6.9 mmol/L,45例,A3组FBG≥7.0 mmol/L,19例。结果 (1)400例人群中,HbA1c≥6.0%,88例,异常率为22.0%;FBG≥6.1mmol/L,54例,异常率13.5.%,HbA1c的异常率高于FBG,P<0.05。(2)A1组HbA1c>≥6.0%,29例,占8.6%;A2组HbA1c≥6.0%,41例,占91.1%;A3组HbA1c≥6.0%,18例,占94.7%;(3)400例人群中,HbA1c≥6.0%或FBG≥6.1mmol/L,93例,异常率23.3%%。结论 HbA1c筛查糖尿病高危人群血糖异常的敏感性高于空腹血糖,两者联合检查有助发现更多糖代谢异常的患者。     

糖化血红蛋白诊断糖尿病标准的初步探讨

目的初步评估使用糖化血红蛋白(HbA1c)诊断糖尿病(DM)的最佳切点,探讨美国糖尿病协会(ADA)推荐的HbA1c≥6.5%作为糖尿病诊断标准是否适用于中国人群。方法 2010年6月至2011年10月在南京明基医院门诊进行75 g口服葡萄糖耐量试验的未被诊断为糖尿病的患者393例,同时测定其HbA1c。以世界卫生组织(WHO)的标准诊断DM,用受试者工作特征曲线(ROC)分析HbA1c诊断DM的能力。结果以非DM组为对照组,用HbA1c来诊断DM时,ROC曲线下面积(AUCROC)为0.926,最佳切点为6.3%,敏感度为91.1%,特异度为88.0%。当切点为6.5%时,敏感度下降为81.8%,特异度为93.7%。结论 HbA1c诊断DM的最佳切点为6.3%,ADA推荐HbA1c≥6.5%的诊断标准也许更适合欧美人群,中国人群的诊断标准仍有待大范围调查后确定。     

糖化血红蛋白对妊娠期糖尿病筛查及年龄依赖性发病率的价值探讨

目的探讨糖化血红蛋白(HbA1c)筛查妊娠期糖尿病(GDM)及年龄依赖性发病率的价值。方法美国糖尿病协会(ADA)葡萄糖耐量试验(OGTT)作为诊断GDM标准,将1 600例妊娠妇女(孕期24~28周)分为健康妊娠组1 319例、GDM组281例,同时测定2组HbA1c和空腹血糖(FPG)、1h及2h血糖,并进行统计学及受试者工作特征(ROC)曲线分析。结果 GDM组的HbA1c值显著高于健康妊娠组(P0.05)。当HbA1c诊断截点4.895%时,ROC曲线下面积(AUC)0.905,敏感性85.8%,特异性81.9%;FPG、1h血糖和2h血糖诊断GDM的ROC AUC分别为0.879、0.796及0.762。随着年龄的增加,不同年龄阶段GDM组中大于HbA1c诊断截点(4.895%)比例呈上升的趋势。结论随着年龄的增加,不同年龄阶段GDM组中HbA1c诊断GMD比例呈上升的趋势。OGTT与HbA1c联合检测能提高GDM诊断准确性,在GDM诊断及监测中有重要价值。     

HbA1c measurement improves the detection of type 2 diabetes in high-risk individuals with nondiagnostic levels of fasting plasma glucose: the Early Diabetes Intervention Program (EDIP)

OBJECTIVE: Whereas new diagnostic criteria based on a fasting plasma glucose (FPG) of > 126 mg/dl (7.8 mmol/l) have improved the detection of diabetes, multiple reports indicate that many people with diabetes diagnosed by 2-h oral glucose tolerance test (OGTT) glucose measurements > or = 11.1 mmol/l (200 mg/dl) would remain undiagnosed based on this FPG criteria. Thus, improved methods to detect diabetes are particularly needed for high-risk individuals. We evaluated whether the combination of FPG and HbA1c measurements enhanced detection of diabetes in those individuals at risk for diabetes with nondiagnostic or minimally elevated FPG. RESEARCH DESIGN AND METHODS: We analyzed FPG, OGTT, and HbA1c data from 244 subjects screened for participation in the Early Diabetes Intervention Program (EDIP). RESULTS: Of 244 high-risk subjects studied by FPG measurements and OGTT, 24% of the individuals with FPG levels of 5.5-6.0 mmol/l (100-109 mg/dl) had OGTT-diagnosed diabetes, and nearly 50% of the individuals with FPG levels of 6.1-6.9 mmol/l (110-125 mg/dl) had OGTT-diagnosed diabetes. In the subjects with OGTT-diagnosed diabetes and FPG levels between 5.5 and 8.0 mmol/l, detection of an elevated HbA1c (>6.1% or mean + 2 SDs) led to a substantial improvement in diagnostic sensitivity over the FPG threshold of 7.0 mmol/l (61 vs. 45%, respectively, P = 0.002). Concordant FPG levels > or = 7.0 mmol/l (currently recommended for diagnosis) occurred in only 19% of our cohort with type 2 diabetes. CONCLUSIONS: Diagnostic criteria based on FPG criteria are relatively insensitive in the detection of early type 2 diabetes in at-risk subjects. HbA1c measurement improves the sensitivity of screening in high-risk individuals.     

Hemoglobin A1c and glucose criteria identify different subjects as having type 2 diabetes in middle-aged and older populations: The KORA S4/F4 Study

Abstract

Objective. The American Diabetes Association (ADA) has recently recommended HbA1c for diagnosing diabetes as an alternative to glucose-based criteria. We compared the new HbA1c-based criteria for diagnosis of diabetes and prediabetes with the glucose-based criteria.

Research design and methods. In the population-based German KORA surveys (S4/F4) 1,764 non-diabetic participants aged 31–60 years and 896 participants aged 61–75 years underwent measurements of HbA1c, fasting plasma glucose (FPG), and 2-h glucose.

Results. Only 20% of all subjects diagnosed with diabetes by glucose or HbA1c criteria had diabetes by both criteria; for prediabetes, the corresponding figure was 23%. Using HbA1c ≥ 6.5%, the prevalence of diabetes was strongly reduced compared to the glucose criteria (0.7% instead of 2.3% in the middle-aged, 2.9% instead of 7.9% in the older subjects). Only 32.0% (middle-aged) and 43.2% (older group) of isolated impaired glucose tolerance (i-IGT) cases were detected by the HbA1c criterion (5.7% ≤ HbA1c < 6.5%).

Conclusion. By glucose and the new HbA1c diabetes criteria, different subjects are diagnosed with type 2 diabetes in middle-aged as well as older subjects. The new HbA1c criterion lacks sensitivity for impaired glucose tolerance.     

Performance of HbA1c as an Early Diagnostic Indicator of Type 1 Diabetes in Children and Youth

OBJECTIVE The aim of this study was to evaluate HbA(1c) as an alternative criterion for impaired glucose tolerance (IGT) or type 1 diabetes (T1D) in high-risk subjects <21 years of age. RESEARCH DESIGN AND METHODS Subjects <21 years of age who participated in the prospective DPT-1, TEDDY, TRIGR, and Type 1 Diabetes TrialNet Natural History (TrialNet) studies and had an HbA(1c) within 90 days of an OGTT with a 2-h plasma glucose (2-hPG) measure were included. An OGTT of 140-199 mg/dL defined IGT, and an OGTT with 2-hPG ≥200 mg/dL or fasting plasma glucose ≥126 mg/dL defined diabetes. HbA(1c) ≥5.7% defined IGT, and HbA(1c) ≥ 6.5% defined diabetes. Receiver-operating characteristic curve analysis was used to assess diagnostic accuracy of HbA(1c) compared with OGTT. RESULTS There were 587 subjects from DPT-1, 884 from TrialNet, 91 from TEDDY, and 420 from TRIGR. As an indicator for IGT, HbA(1c) sensitivity was very low across the studies (8-42%), and specificity was variable (64-95%). With HbA(1c) ≥6.5% threshold used for T1D diagnosis, the sensitivity was very low and specificity was high (sensitivity and specificity: DPT-1 24 and 98%, TrialNet 28 and 99%, TEDDY 34 and 98%, and TRIGR 33 and 99%, respectively). The positive predictive value of HbA(1c) ≥6.5% for the development of T1D was variable (50-94%) across the four studies. CONCLUSIONS HbA(1c) ≥6.5% is a specific but not sensitive early indicator for T1D in high-risk subjects <21 years of age diagnosed by OGTT or asymptomatic hyperglycemia. Redefining the HbA(1c) threshold is recommended if used as an alternative criterion in diagnosing T1D.