HbA1c增高、糖耐量异常与老年糖尿病发病的相关性

目的研究空腹糖耐量异常(IFG)、糖化血红蛋白(Hb A1c)增加或者两者同时具有是否能预测老年人群发生糖尿病的风险。方法采用前瞻性研究方法,以江苏省多代谢异常和代谢综合征综合防治研究队列满足条件的人群为研究对象,比较基线IFG[空腹血糖(FPG)100～125 mg/dl]及Hb A1c增加(Hb A1c 5.7%～6.4%)的研究人群在随访后发生糖尿病的风险。采用Cox回归分析模型计算在调整年龄、性别、体重指数(BMI)、吸烟、体力活动后,观察IFG、Hb A1c与随访发生糖尿病的关系。结果在607例研究人群中(平均年龄66.2岁,男性41.8%),经过5年的随访有29例进展为糖尿病。在调整后的Cox回归分析中,基线IFG人群相比于基线FPG100 mg/dl的人群发生糖尿病的RR为4.303(3.119～5.936),而基线仅Hb A1c增高人群相比于Hb A1c5.7%的人群,其发生糖尿病的RR值为2.648(2.117～3.314)。而同时考虑IFG、Hb A1c后,仅有IFG的人群、仅Hb A1c增高的人群、同时合并IFG、Hb A1c增加的人群发生糖尿病的风险分别是3.603(2.526～5.137)、5.646(3.964～6.751)、10.098(6.160～16.551)。结论老年人群同时患有IFG、Hb A1c增加,其随后进展为糖尿病的风险也增加。如果同时检测FPG、Hb A1c有助于筛查有糖尿病高危风险的老年人群。     

空腹血糖和糖化血红蛋白用于筛查糖尿病的研究

目的评估空腹血糖(FPG)和糖化血红蛋白(HbA1c)在筛查糖尿病(DM)和糖耐量受损(IGT)中的应用价值。方法北京地区研究对象1118名,为明确DM诊断而就诊者和DM高危人群接受DM筛查者,男489名,女629名,平均48±12岁,行口服葡萄糖耐量试验(OGTT)并测定HbA1c。结果按照1999年WHO的DM诊断标准,本研究人群糖耐量正常(NGT)、空腹血糖受损(IFG)、IGT、IGT合并IFG和DM者分别为510、35、155、52、366例。采用受试者工作特征曲线(ROC曲线)判断,与以OGTT诊断的DM状态相关的FPG临界点为6.2mmol/L,敏感性和特异性分别为85.0%和90.4%,曲线下面积0.943(95%CI0.927～0.959),阳性似然比8.9,阴性似然比0.2;与以OGTT诊断的DM状态相关的HbA1c临界点为6.2%,敏感性和特异性分别为86.6%和77.5%,曲线下面积0.896(95%CI0.876～0.916),阳性似然比3.9,阴性似然比0.2。与IGT状态相关的FPG临界点为5.1mmol/L,敏感性和特异性分别为65.2%和68.3%,曲线下面积为0.729,阳性似然比2.1,阴性似然比0.5。与IGT状态相关的HbA1c临界点为5.7%,敏感性和特异性分别63.3%和56.5%,曲线下面积为0.634,阳性似然比1.5,阴性似然比0.7。结论6.2mmol/L6.2%时应进一步行OGTT了解2h血糖以明确有无DM,FPG和HbA1c不适用于筛查IGT人群。     

以糖化血红蛋白A1c作为糖尿病诊断和筛查的指标

糖化血红蛋白（Hb）A1c用于评价糖尿病患者的血糖控制水平已有几十年历史。尽管近年来HbA1c的检测方法、计量单位以及标准化日臻完善,但迄今为止的指南仍没有推荐使用HbA1c筛查与诊断糖尿病,而是通过检测空腹或糖负荷之后的血清葡萄糖来筛查与诊断糖尿病。鉴于现有诊断方法存在的缺陷,以及近年来HbA1c检测技术的进步,HbA1c用于糖尿病的筛查与诊断已成为一种趋势。在第69届美国糖尿病协会（ADA）年会上,由ADA、欧洲糖尿病研究学会（EASD）以及国际糖尿病联盟（IDF）组成的国际专家委员会指出,将HbA1c≥6．5％作为筛查与诊断糖尿病的标准具有合理性,其准确性、敏感性与特异性也较为满意,其与血糖联合使用,可进一步提高糖尿病诊断的敏感性,更有利于临床实践。但是,临床医生需要了解影响HbA1c检测结果的因素、HbA1c的标准化、HbA1c用于筛查与诊断糖尿病的循证医学证据、基于HbA1c与血糖检测的糖尿病筛查标准等诸多问题。     

糖化血红蛋白在糖尿病及空腹血糖受损诊断中的价值

目的 探讨HbA1c在糖尿病及IFG诊断中的意义。方法选取526名未诊断糖尿病及IFG者同时检测HbA1C和FPG。按ADA诊断标准（FI）G≥7．0mmol／L）、IFG标准（5．6mmol／L≤FPG46．9mmol／L）和2010年ADA新标准（HbA1c≥6．5％及5．7％≤HbA1c≤6．4％）将研究对象分组。以FPG为“金标准”,统计HbA1C诊断糖尿糖及IFG的敏感性（s）、特异性（Sp）、阳性似然比（＋ut）、阴性似然比（-LR）。结果HbA1c≥6．5％诊断糖尿病的s为96％,Sp为95％,＋LR为19．2,-LR为0．042;5．7N≤HbA1c≤6．4％诊断IFG的S为26％,sp为94％,＋LR为4．3,-LR为0．79。结论HbA1C诊断糖尿病有较高的诊断敏感性和特异性,在诊断IFG时特异性较高,而敏感性较低。     

The glucose tolerance test, but not HbA(1c), remains the gold standard in identifying unrecognized diabetes mellitus and impaired glucose tolerance in hypertensive subjects

The objective of this study was to compare the value of the oral glucose tolerance test (GTT), glycated hemoglobin concentration (HbA(1c)), and fasting plasma glucose (FPG) for identifying unrecognized diabetes mellitus (DM) and impaired glucose tolerance (IGT) in hypertensive subjects. One hundred forty-four consecutive subjects who were not known to have DM and who were attending the Hypertension Clinic underwent 24-hour ambulatory blood pressure (BP) monitoring. A GTT and an HbA(1c) measurement were also carried out. Abnormal results from GTT were found in 94 patients (65%). Results from FPG were not different between those with DM and IGT but were significantly higher than in the euglycemic subjects. The FPG was between 110-125 mg/dL (6.1-6.9 mmol/L) in 31% (n = 20) of patients with IGT and in 53% (n = 16) of those with DM. With use of the previously published criteria to diagnose DM of FPG > or = 103 mg/dL (5.7 mmol/L) and HbA(1c) > or = 5.9%, 33% of our diabetic subjects and 75% of those with IGT would have been misclassified as euglycemic. The previously reported cut-off point for HbA(1c) of >6.1% to diagnose DM was present in 77% of our patients with DM and in 14% (n = 9) of the patients with IGT. Multiple regression analysis showed that an abnormal result from GTT was independent of the level of clinical or ambulatory BP, nocturnal BP dip, cholesterol level, smoking history, race, or class of antihypertensive medication taken. FPG levels or HbA(1c), or their combination, are not accurate enough to identify DM or IGT in patients attending a hospital Hypertension Clinic. A GTT may be required in these patients to reliably identify those with DM or IGT.     

Fructosamine and HbA1c during monitoring of glucose levels in diabetes

The authors compared the nycthemeral variations of fructosamine levels in nineteen patients with diabetes to fluctuations in their glucose levels. Thirty-five other patients with poorly controlled diabetes were given an optimal treatment then followed up for 2 months (mean glucose levels, fructosamine and HbA1c assays). Mean nycthemeral variations in fructosamine levels did not appear to be correlated with glucose levels. However, intraindividual nycthemeral variability was greater than the analytic variability. After correction for total protein levels this variability was smaller but remained significative. In this longitudinal study, fructosamine and HbA1c levels decreased when control of glucose levels improved. However, decreases were notably greater in HbA1c than in fructosamine compared at 15, 45 and 60 days of follow up. Inversely, fructosamine was correlated better with the mean glucose levels of the preceding 7 days than was HbA1c. When mean glucose levels were calculated for the 15, 30, 45 and 60 preceding days, the results favored HbA1c. The findings presented in this study show that HbA1c remains the best criteria for monitoring medium term glucose levels. However, further word is needed before this conclusion can be confirmed.     

Seasonal variation in fasting glucose and HbA1c in patients with type 2 diabetes

Seasonal variations in fasting glucose and HbA1c levels in 638 diabetic patients (attending a primary care diabetic clinic during 2003–2007) were examined and found to be significantly higher in colder than in warmer months. Moreover, there were apparent peaks in fasting glucose levels after Christmas and Easter months. This study provides further evidence of monthly fluctuations in glycemic control, underscoring the need to consider seasonal/cultural effects when managing diabetic patients.     

2型糖尿病患者动态血糖变化与糖化血红蛋白水平的相关性分析

目的探讨2型糖尿病患者动态血糖变化与糖化血红蛋白(HbAlc)水平的相关性,为预防2型糖尿病并发症的发生提供参考。方法选取2009-05～2011-05收治的18例2型糖尿病患者,采用动态血糖监测系统(CGMS)观察2型糖尿病患者血糖变化与HbAl c的相关性。结果经Pearson分析显示,HbAlc与日内血糖水平呈正相关(P0.05),与餐后血糖波动幅度(PPGE)无明显相关性(P0.05)。结论 CGMS能详细显示日内血糖波动情况,HbAlc能反映日内整体血糖水平。     

Revisiting the oral glucose tolerance test criterion for the diagnosis of diabetes

OBJECTIVE: The Expert Committee on the Diagnosis and Classification of Diabetes retained the 2-hour glucose concentration on an oral glucose tolerance test of ≥11.1 mmol/L (200 mg/dL) as a criterion to diagnose diabetes. Since glycated hemoglobin levels have emerged as the best measure of long-term glycemia and an important predictor of microvascular and neuropathic complications, we evaluated the distribution of hemoglobin A1C (Hb A1C) levels in individuals who had undergone an oral glucose tolerance test to determine how well 2-hour values could identify those with normal versus increased Hb A1C levels. DESIGN: A cross-sectional analysis of 2 large data sets was performed. We cross-tabulated 2-hour glucose concentrations on an oral glucose tolerance test separated into 4 intervals (<7.8 mmol/L [140 mg/dL], 7.8–11.0 mmol/L [140–199 mg/dL], 11.1–13.3 mmol/L [200–239 mg/dL], and ≥13.3 mmol/L [240 mg/dL]) with Hb A1C levels separated into 3 intervals (normal; <1% above the upper limit of normal; and greater than or equal to the upper limit of normal +1%). RESULTS: Approximately two thirds of patients in both data sets with 2-hour glucose concentrations of 11.1 to 13.3 mmol/L (200–239 mg/dL) had normal Hb A1C levels. In contrast, 60% to 80% of patients in both data sets with 2-hour glucose concentrations ≥13.3 mmol/L (240 mg/dL) had elevated Hb A1C levels. CONCLUSION: Since Hb A1C levels are the best measures presently available that reflect long-term glycemia, we conclude that the 2-hour glucose concentration criterion on an oral glucose tolerance test for the diagnosis of diabetes should be raised from ≥11.1 mmol/L (200 mg/dL) to ≥13.3 mmol/L (240 mg/dL) to remain faithful to the concept that diagnostic concentrations of glucose should predict the subsequent development of specific diabetic complications (e.g., retinopathy). Presented at the American Diabetes Association meeting, San Diego, Calif, June 1999.     

Predictive value of HbA1c level for in-hospital acute coronary syndrome patients with diabetes

Background Diabetes mellitus (DM) is the major risk factor of coronary artery disease (CAD), and the control status of blood sugar has direct effect on the prognosis of CAD. HbA1c is the important parameter reflecting control status of blood sugar, however, it is unclear about the value of in-hospital HbA1c in patients with acute coronary syndrome (ACS). Methods A retrospective analysis was performed for 236 in-hospital diabetic patients with ACS. Patients were stratified into two groups according to HbA1c level when admission (Well controlled group (HbA1c≤7.0%) and High HbA1c group (HbA1c > 7.0% ); major adverse cardiovascular events (MACE) group and Non-MACE group). In-hospital MACE and mortality were set as the observation target. Results 282 patients (112 in Well controlled group and 170 in High HbA1c group) were enrolled, of which 146 (51.77%), 63 (23.34%), and 73 (25.89%) patients respectively had unstable angina (UA), non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). Inhospital all-cause mortality and in-hospital MACE were both similar in Well controlled group and High HbA1c group (6.25% vs. 7.06% and 15.18% vs. 16.47%, P > 0.05). In MACEs, cardiac death (4.46% vs. 5.29%), recurrent myocardial infarction (2.68% vs. 2.94%), hemorrhage events (5.35% vs. 5.29%), malignant arrhyth- mia (6.25% vs. 5.29%), cardiac shock (4.46% vs. 4.12%), acute heart failure (8.93% vs. 10.0%), revascularization (4.46% vs. 5.29%) were also all similar in both two groups. In addition, there were no significant difference in HbA1c level between MACE group and Non-MACE group. Single-factor logistic regression analysis showed that HbA1c was not a risk factor for in-hospital MACE (P > 0.05) 1 . Conclusion The present study sug-gests that admission HbA1c is not the risk factor of in-hospital MACE in ACS patients with diabetes.     

冠状动脉搭桥术后应激性高血糖与术前糖化血红蛋白的关系研究

目的:探讨冠状动脉搭桥手术患者术后应激性血糖与术前糖化血红蛋(HbA1c)的关系。方法:回顾分析96例无糖尿病史且行心脏冠状动脉搭桥手术患者,术前完善了口服葡萄糖耐量(OGTT)试验除外糖尿病,根据HbA1c值分为相对高糖化组(HbA1c≥6.0%)和对照组(HbA1c<6.0%),观察2组术前基线指标和术后应激性血糖有无差异及相关性。结果:高糖化组与对照组术前年龄(P=0.001)、体质量指数(BMI)(P=0.007)、腰臀比(WHR)(P=0.0001)、胰岛素抵抗(HOMA-IR)指数(P=0.001)以及术后应激性血糖(P=0.0001)差异均有统计学意义;高糖化组术后应激性高血糖患者明显多于对照组(P=0.001),线性回归分析显示术前HbA1c值和应激性血糖密切相关(R2=0.224)。结论:术前超质量或腹型肥胖尤其是年龄大者,即使无糖尿病也应测定HbA1c,如果HbA1c≥6.0%应积极防治术后应激性高血糖。     

Racial and ethnic differences in the relationship between HbA1c and blood glucose: implications for the diagnosis of diabetes

Hemoglobin A1c (HbA1c) is widely used as an index of mean glycemia in diabetes, as a measure of risk for the development of diabetic complications, and as a measure of the quality of diabetes care. In 2010, the American Diabetes Association recommended that HbA1c tests, performed in a laboratory using a method certified by the National Glycohemoglobin Standardization Program, be used for the diagnosis of diabetes. Although HbA1c has a number of advantages compared to traditional glucose criteria, it has a number of disadvantages. Hemoglobinopathies, thalassemia syndromes, factors that impact red blood cell survival and red blood cell age, uremia, hyperbilirubinemia, and iron deficiency may alter HbA1c test results as a measure of average glycemia. Recently, racial and ethnic differences in the relationship between HbA1c and blood glucose have also been described. Although the reasons for racial and ethnic differences remain unknown, factors such as differences in red cell survival, extracellular-intracellular glucose balance, and nonglycemic genetic determinants of hemoglobin glycation are being explored as contributors. Until the reasons for these differences are more clearly defined, reliance on HbA1c as the sole, or even preferred, criterion for the diagnosis of diabetes creates the potential for systematic error and misclassification. HbA1c must be used thoughtfully and in combination with traditional glucose criteria when screening for and diagnosing diabetes.