空腹血糖及糖化血红蛋白用于筛查糖耐量减退的比较性研究

目的比较空腹血糖（FPG）和糖化血红蛋白（HbAlc）在筛查糖耐量减退（IGT）中的应用价值。方法到我院门诊为明确有无血糖异常而就诊者336人，测定空腹血糖、糖化血红蛋白，并行口服葡萄糖耐量试验（OGTT）。结果按照1999年WHO的DM诊断标准，本研究人群空腹血糖〈6．1者124例，≥6．1-〈7．0者56例，≥7．0者156例；糖化血红蛋白〈6．1者84例，≥6．1者252例；OGTT2 hPG〈7．8者92例，≥7．8-〈11．1者99例，≥11．1者145例。结论糖化血红蛋白和空腹血糖均不适用于筛查IGT人群，但糖化血红蛋白比空腹血糖提示病人是否存在血糖异常更敏感。     

急性脑梗死患者糖调节受损的分布及其临床价值分析

目的：探讨急性脑梗死糖调节受损（IGR）的分布情况,并就FG、HbA1c、餐后2h血糖及胰岛素对急性脑血管患者血糖评估的价值进行重新评价。方法：测定2007年1月-2008年12月急性脑梗死患者的空腹血糖及胰岛素、餐后2h血糖及胰岛素、HbA1c等,按世界卫生组织的正常血糖、IGR、糖尿病诊断标准进行评定,了解IGR在急性脑血管病的分布情况,并对以上各指标的临床价值进行重新评估。结果：263例急性脑梗死患者既往已确诊有2型糖尿病史者103例,经连续2次空腹血糖测定≥7．0mmol·L^-1而新确诊为2型糖尿病者17例,IGR5例;经口服糖耐量试验（OGTT）试验后新诊糖尿病患者36例,即入院后的急性脑梗死患者中新诊糖尿病患者为53倒,占总病例数的20．15％,在263例患者,最终确诊糖尿患者数为156例,即合并糖尿患者比例由入院时的39．16％增加至59．32％;另新诊断IGR患者27例,其中IFG10例,I-IGT12例,IFG＋IGT5例,糖代谢异常率由入院时的47．53％上升至OGTT试验后的69．58％。NGT组、IGR组、DM组的HbAIc异常率分别为5／80（6．25％）,13／27（48．15％）,132／156（84．62％）,空腹胰岛素值分别为：10．06±9．28,9．55±5．42,9．98±5．26mU·L^-1,餐后2h胰岛素分别为28．18±18．06,50．77±32．37,35．6±27．2mu·L^-1.NIHSS评分分别为4．21±2．27,4．80±2．81,5．83±2．88。结论：急性脑梗死患者中存在广泛的糖代谢畀常,仅据空腹血糖和既往糖尿病史将使81．48％IGR、20．15％糖尿病病人漏诊,对急性脑血管病人进行餐后2h血糖及胰岛素、HbA1c测定有利于对患者血糖的正确评估及治疗。     

Is using WHO criteria for impaired fasting glycaemia appropriate as an indication for OGTT in patients at high risk of developing diabetes?

Aim: Impaired fasting glycaemia (IFG) is an indication for oral glucose tolerance test (OGTT). World health organisation and International Diabetes Federation define IFG as fasting plasma glucose (FPG) levels of 6.1–6.9 mmol/l. However, American Diabetes Association still recommends a range of 5.6–6.9 mmol/l as IFG. We performed an audit to assess the outcome of OGTT at various cut offs of FPG levels in patients at high risk of developing diabetes. Methods: Laboratory data on OGTT performed over a period of 1 year in a district general hospital were collected. Patients with FPG levels between 5.6 and 6.9 mmol/l were selected and the outcome was analysed. Results: Our audit shows that in patients with FPG levels of 5.6–6.0 mmol/l, 19% had diabetes and 43% had impaired glucose tolerance (IGT). Conclusion: The percentage of subjects with abnormal OGTT in our study is much higher than that of Decode study [Diabetologica, 42 (1999) 647] (7% diabetes and 29% IGT). However, Decode study had included general population whereas our data were collected from subjects who are at high risk of developing diabetes. We conclude that in these subjects the lower cut off level of 5.6 mmol/l for FPG should be used as an indication for OGTT.     

Comparison of HbA1c and oral glucose tolerance test for diagnosis of diabetes in patients with coronary artery disease

Background

Measurement of glycated hemoglobin A1c (HbA1c) to diagnose diabetes mellitus (DM-2) is recommended by several expert groups. DM-2 occurs very frequently among patients with coronary artery disease (CAD). Therefore, we aimed to investigate the diagnostic strengths of HbA1c and oral glucose tolerance test (OGTT) in detecting latent glucometabolic disturbances among patients with CAD.

Materials and methods

One hundred ninety-nine consecutive patients admitted with CAD were included in this observational study. Fasting plasma glucose as well as HbA1c measurement was performed in all study participants and those without preexisting DM-2 underwent an OGTT.

Results

Patients were subdivided according to their medical history into those with previous DM-2 (n?=?37). The remaining 162 patients underwent OGTT, which revealed 39 patients with diabetes (DM-_OGTT), 35 with impaired glucose tolerance (IGT), 20 with impaired fasting glucose (IFG) and 68 with normal glucose tolerance (NGT). Using HbA1c resulted in 6.8% DM and 45.6% at risk (HbA1c 5.7–6.4%) diagnosis. OGTT identified 24.1% DM (p?=?0.002 compared with HbA1c) and 21.6% IGT patients. Among those with intermediate HbA1c (5.7–6.4%) 26.5% patients were NGT and only 30.9% displayed DM-2 by use of OGTT. Among patients with HbA1c of <5.7%, 44% (n?=?31) of patients had disturbed glucose metabolism. Using receiver-operating curve HbA1c cutoff with the highest sensitivity and specificity was found to be 5.8%.

Discussion

There is a large discordance between OGTT and HbA1c in terms of detecting latent DM-2 in patients with CAD. Measurement of HbA1c could result in lower propensity of DM-2 diagnosis.     

口服葡萄糖耐量试验诊断DM、IGT、IFG的临床意义

目的　探讨空腹血糖 (FPG) <7.0mmol/L ,OGTT试验诊断糖尿病 (DM )、糖耐量减低 (IGT)及空腹血糖损害 (IFG)的价值。方法　挑选经体检确认FPG >7.0mmol/L人群作为观察对象 ,经馒头餐后 2h PG≥ 6.7mmol/L人员 ,施以OGTT ,根据 1999年WHO标准分为三组 :DM组、IGT组及IFG组。给每一组人员检查 2 4h尿微量白蛋白 (UmALB)。结果　DM、IGT及IFG男性检出率分别为 6.6%、10 .5 %及 5 .1% ,女性为 5 .1%、12 .5 %及 3 .3 % ,男性DM及IFG检出率高于女性 (P <0 .0 5 ) ,女性IGT检出率显著高于男性 (P <0 .0 1) ;2 4hUmALB ,FPG诊断DM组为 43 .2± 14 .3mg、OGTT诊断DM组为 3 0 .4± 15 .3mg、IGT组为 2 1.7± 8.5mg、IFG组为 7.7± 3 .6mg、正常对照组 7.5± 4.6mg ,DM组、IGT组均显著高于正常对照组 (P <0 .0 1) ,IFG组与正常对照组无差异 (P >0 .0 5 )。结论　对于FPG <7.0mmol/L者 ,应以OGTT试验来筛查患者是否有糖尿病或糖耐量异常。     

Identification and treatment of prediabetes to prevent progression to type 2 diabetes

Overt type 2 diabetes is usually preceded by a condition known as prediabetes, which is characterized by impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). Both IFG and IGT exhibit elevated glucose levels that are not sufficient to be classified as diabetes but that represent the development of insulin resistance. Achieving glycemic control in patients with prediabetes through lifestyle and pharmacologic interventions can effectively prevent or delay the development of diabetes and its associated complications. The first step, however, is to identify patients at risk. Although patients can be identified with an oral glucose tolerance test (OGTT) or a fasting plasma glucose (FPG) screening, a normal FPG does not preclude an elevated OGTT and, therefore, the presence of prediabetes. For patients who progress to type 2 diabetes, intensive therapy aimed at reducing and maintaining glycosylated hemoglobin (A1C) levels <7% has been shown to reduce the risk of complications. An A1C level > or =7% should signal the need to initiate or change therapy to achieve glycemic goals.     

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.     

Utility of hemoglobin A1c for the identification of individuals with diabetes and prediabetes in a Chinese high risk population

Abstract Background. The aim of the study was to assess the utility of Hemoglobin A1c (HbA1c) to identify individuals with undiagnosed DM and prediabetes (preDM) in the high risk population of Chinese people. Methods. A total of 424 high risk individuals without known diabetes, who met at least three of the high risk factors for DM (hypertension, abnormal blood lipid, family history of DM and high BMI) were selected for this study, HbA1c, fasting plasma concentrations of glucose (FPG) and a 75 g oral glucose tolerance test (OGTT) were measured. The performance of HbA1c in relation to undiagnosed DM and preDM investigated through receiver operating characteristic (ROC) curves, the reference for DM and preDM, are according to the 2011 WHO-FPG/OGTT criteria and the appropriate cut-off points of HbA1c for DM and preDM were assessed. The properties of HbA1c diagnosing DM and preDM were also compared with that of the fasting plasma glucose (FPG). Results. It was shown that the AUC (area under the curve) of the ROC curve for HbA1c predicting undiagnosed DM was similar to that of FPG, and the cut-off point of HbA1c 6.2% was optimal for predicting DM, with a sensitivity of 66%, and a specificity of 91%. Furthermore, the cut-off point of HbA1c was 5.9% for preDM with a sensitivity of 70%, a specificity of 87%. Conclusion. Collectively, this study found that the measurement of HbA1c may be efficient to diagnosis undiagnosed both DM and preDM with the cut-off point of 6.2% and 5.9%, respectively.     

The 1997 American Diabetes Association and 1999 World Health Organization criteria for hyperglycemia in the diagnosis and prediction of diabetes

OBJECTIVE: The 1997 American Diabetes Association (ADA) and the 1985 and 1999 World Health Organization (WHO) criteria for diabetes and hyperglycemia differ. The appropriateness of these diagnostic criteria in terms of individuals identified as abnormal and their prognosis has been debated. The purpose of this study is to compare the classifications of people by these criteria and to compare fasting and postload plasma glucose concentrations in the prediction of diabetes. RESEARCH DESIGN AND METHODS: The frequencies of diabetes by the 3 sets of criteria were compared in 5,023 adult Pima Indians not taking hypoglycemic drugs. Among nondiabetic subjects, fasting plasma glucose (FPG) and 2-h postload plasma glucose (2-h PG) concentrations and categories of impaired glucose regulation or diabetes were evaluated as predictors of diabetes defined by 1999 WHO criteria. RESULTS: The frequency of diabetes was 12.5% by 1997 ADA criteria, 14.6% by 1985 WHO criteria, and 15.3% by 1999 WHO criteria. The incidence of diabetes was strongly related to higher FPG and 2-h PG, each of which had very similar predictive powers. Impaired glucose tolerance (IGT) was more common than impaired fasting glucose (IFG) (15 vs. 5%), but the 5-year incidence of diabetes was higher in IFG than IGT (37 vs. 24%). CONCLUSIONS: The prevalence and incidence of diabetes are somewhat lower with the ADA criteria than with the 1985 or 1999 WHO criteria. The intermediate categories of glycemia differ substantially IFG defines a smaller number of people who are at higher risk of developing diabetes than those with IGT. More people at high risk of diabetes could be identified by using either IFG or IGT, as recommended by the 1999 WHO criteria, or by using the FPG concentration alone, but with a lower cutoff value.     

Changing the definition of impaired fasting glucose: impact on the classification of individuals and risk definition

OBJECTIVE: This study evaluates the impact of lowering the diagnostic threshold for impaired fasting glucose (IFG) from 6.1 to 5.6 mmol/l as proposed by the American Diabetes Association (ADA) on the prevalence of the condition, classification of individuals, and risk definition. RESEARCH DESIGN AND METHODS: A total of 1,285 employees of the Italian Telephone Company aged 35-59 years without known diabetes underwent an oral glucose tolerance test (OGTT). BMI, serum cholesterol, triglycerides, and blood pressure were measured. Medication use was recorded. RESULTS: With the new ADA criterion, the proportion of people diagnosed with IFG increased from 3.2 to 9.7%. The newly proposed IFG category identified 41% of all subjects with impaired glucose tolerance (IGT) compared with 16.2% identified with the use of the World Health Organization criterion for IFG; the improvement in accuracy has been achieved at the cost of classifying more previously "normal" subjects as having IFG (from 2.3 to 7.3%). Both IFG and IGT were associated with an unfavorable risk profile for diabetes and cardiovascular disease, with a higher estimated risk for IGT than IFG. CONCLUSIONS: Even with the revised diagnostic criterion, IFG and IGT identify distinct groups that have a different background risk. The cost/benefit of preventive measures tested in people with IGT may not apply to the new IFG category.     

Using HbA(1c) to improve efficacy of the american diabetes association fasting plasma glucose criterion in screening for new type 2 diabetes in American Indians: the strong heart study

OBJECTIVE: To find an optimal critical line in the fasting plasma glucose (FPG)-HbA(1c) plane for identifying diabetes in participants with impaired fasting glucose (IFG) and thereby improve the efficacy of using FPG alone in diabetes screening among American Indians. RESEARCH DESIGN AND METHODS: We used FPG, 2-h postload glucose (2hPG), and HbA(1c) measured in the 2,389 American Indians (aged 45-74 years, without diabetes treatment or prior history of diabetes) in the Strong Heart Study (SHS) baseline (second) examination. Participants were classified as having diabetes if they had either FPG > or =126 mg/dl or 2hPG > or =200 mg/dl, as having IFG if they had 110 < or = FPG < 126 mg/dl, and as having normal fasting glucose (NFG) if they had FPG <110, according to the American Diabetes Association (ADA) definition. Logistic regression models were used for identifying diabetes (2hPG > or =200 mg/dl) in IFG participants. The areas under the receiver operating characteristic (ROC) curves generated by different logistic regression models were evaluated and compared to select the best model. A utility function based on the best model and the cost-to-benefit ratio was used to find the optimal critical line. The data from the second examination were used to study the effect of the time interval between the successive diabetes screenings on both the FPG criterion and the optimal critical line. RESULTS: A total of 37% of all subjects with new diabetes at baseline and 55.2% of those in the second exam had 2hPG > or =200 but FPG <126. There was a very large portion of IFG participants with diabetes (19.3 and 22.9% in the baseline and second exam, respectively). Among the areas under the ROC curves, the area generated by the logistic regression model on FPG plus HbA(1c) is the largest and is significantly larger than that based on FPG (P = 0.0008). For a cost-to-benefit ratio of 0.23888, the optimal critical line that has the highest utility is: 0.89 x HbA(1c) + 0.11 x FPG = 17.92. Those IFG participants whose FPG and HbA(1c) were above or on the line were referred to take an oral glucose tolerance test (OGTT) to diagnose diabetes. The optimal critical line is lower if a successive diabetes screening will be conducted 4 years after the previous screening. CONCLUSIONS: FPG > or =126 and 2hPG > or =200, as suggested by the ADA, are used independently to define diabetes. The FPG level is easy to obtain, and using FPG alone is suggested for diabetes screening. It is difficult to get physicians and patients to perform an OGTT to get a 2hPG level because of the many drawbacks of the OGTT, especially in those patients who already have FPG <126. It is also impractical to conduct an OGTT for everyone in a diabetes screening. Our data show that 37% of all subjects with new diabetes in the SHS baseline exam and 55.2% of those in the second exam have 2hPG > or =200 but FPG <126. These cases of diabetes cannot be detected if FPG is used alone in a diabetes screening. Therefore, although the small portion of diabetes in the NFG group (4.7% in the baseline and 6.9% in the second exam) may be ignored, those cases of diabetes among IFG participants ( approximately 20% in our data) need further consideration in a diabetes screening. It may be worthwhile for those IFG participants identified by the optimal critical line to take an OGTT. The optimal critical line and time interval between successive diabetes screenings need further study.     

Combined use of fasting plasma glucose and glycated hemoglobin A1c in a stepwise fashion to detect undiagnosed diabetes mellitus

Type 2 diabetes mellitus (DM) is a common and serious condition related with considerable morbidity. Screening for DM is one strategy for reducing this burden. In Japan National Diabetes Screening Program (JNDSP) guideline, the combined use of fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) in a stepwise fashion has been recommended to identify the group of people needing life-style counseling or medical care. However, the efficacy of this program has not been fully evaluated, as an oral glucose tolerance test (OGTT) is not mandatory in the guideline. The aim of this study was to assess the validity of the screening test scenario, in which an OGTT would be applied to people needing life-style counseling or medical care on this guideline: FPG 110-125 mg/dl and HbA1c over 5.5%. Subjects were 1,726 inhabitants without a previous history of DM in the Funagata study, which is a population-based survey conducted in Yamagata prefecture to clarify the risk factors, related conditions, and consequences of DM. DM was diagnosed according to the 1999 World Health Organization criteria. The prevalence of undiagnosed DM was 6.6%. The tested screening scenario gave a sensitivity of 55.3%, a specificity of 98.4%, a positive predictive value of 70.8%, and a negative predictive value of 96.9% for undiagnosed DM. In conclusion, the screening test scenario, in which an OGTT would be followed by the combined use of FPG and HbA1c in a stepwise fashion according to the JNDSP guideline, was not effective in identifying people with undiagnosed DM.     

Using metabolic syndrome traits for efficient detection of impaired glucose tolerance

OBJECTIVE: Efficient detection of impaired glucose tolerance (IGT) is needed to implement type 2 diabetes prevention interventions. RESEARCH DESIGN AND METHODS: We assessed the capacity of the metabolic syndrome (MetS) to identify IGT in a cross-sectional analysis of 3,326 Caucasian Framingham Offspring Study (FOS), 1,168 Caucasian and 1,812 Mexican-American San Antonio Heart Study (SAHS), 1,983 Mexico City Diabetes Study (MCDS), and 452 Caucasian, 407 Mexican-American, and 290 African-American Insulin Resistance Atherosclerosis Study (IRAS) men and women aged 30-79 years who had a clinical examination and an oral glucose tolerance test (OGTT) during 1987-1996. Those with diabetes treatment or fasting plasma glucose > or =7.0 mmol/l were excluded (MetS was defined by Third Report of the National Cholesterol Education Program's Adult Treatment Panel criteria and IGT as 2-h postchallenge glucose [2hPG] > or =7.8 mmol/l). We calculated positive (PPV) and negative predictive values (NPV), population attributable risk percentages (PAR%), age- and sex-adjusted odds ratios (ORs), and areas under the receiver operating characteristic curve (AROCs) associated with MetS traits. RESULTS: Among FOS, SAHS, and MCDS subjects, 24-43% had MetS and 15-23% had IGT (including 2-5% with 2hPG > or =11.1 mmol/l). Among those with MetS, OR for IGT were 3-4, PPV were 0.24-0.41, NPV were 0.84-0.91, and PAR% were 30-40%. Among subjects with MetS defined by impaired fasting glucose (IFG) and any two other traits, OR for IGT were 9-24, PPV were 0.62-0.89, NPV were 0.78-0.87, and PAR% were 3-12%. Among IRAS subjects, 24-34% had MetS and 37-41% had IGT. Among those with MetS, ORs for IGT were 3-6, PPVs were 0.57-0.73, and NPVs were 0.67-0.72. In logistic regression models, IFG, large waist, and high triglycerides were independently associated with IGT (AROC 0.71-0.83) in all study populations. CONCLUSIONS: The MetS, especially defined by IFG, large waist, and high triglycerides, efficiently identifies subjects likely to have IGT on OGTT and thus be eligible for diabetes prevention interventions.     

Full Accounting of Diabetes and Pre-Diabetes in the U.S. Population in 1988�C1994 and 2005�C2006

OBJECTIVE—We examined the prevalences of diagnosed diabetes, and undiagnosed diabetes and pre-diabetes using fasting and 2-h oral glucose tolerance test values, in the U.S. during 2005–2006. We then compared the prevalences of these conditions with those in 1988–1994.RESEARCH DESIGN AND METHODS—In 2005–2006, the National Health and Nutrition Examination Survey included a probability sample of 7,267 people aged ≥12 years. Participants were classified according to glycemic status by interview for diagnosed diabetes and by fasting and 2-h glucoses measured in subsamples.RESULTS—In 2005–2006, the crude prevalence of total diabetes in people aged ≥20 years was 12.9%, of which ∼40% was undiagnosed. In people aged ≥20 years, the crude prevalence of impaired fasting glucose was 25.7% and of impaired glucose tolerance was 13.8%, with almost 30% having either. Over 40% of individuals had diabetes or pre-diabetes. Almost one-third of the elderly had diabetes, and three-quarters had diabetes or pre-diabetes. Compared with non-Hispanic whites, age- and sex-standardized prevalence of diagnosed diabetes was approximately twice as high in non-Hispanic blacks (P < 0.0001) and Mexican Americans (P = 0.0001), whereas undiagnosed diabetes was not higher. Crude prevalence of diagnosed diabetes in people aged ≥20 years rose from 5.1% in 1988–1994 to 7.7% in 2005–2006 (P = 0.0001); this was significant after accounting for differences in age and sex, particularly in non-Hispanic blacks. Prevalences of undiagnosed diabetes and pre-diabetes were generally stable, although the proportion of total diabetes that was undiagnosed decreased in Mexican Americans.CONCLUSIONS—Over 40% of people aged ≥20 years have hyperglycemic conditions, and prevalence is higher in minorities. Diagnosed diabetes has increased over time, but other conditions have been relatively stable.Diabetes and its complications remain major causes of morbidity and mortality in the U.S. (1). Estimated economic costs of diabetes in medical expenditures and lost productivity total $174 billion in the U.S. in 2007 (2). In 1999–2002, the crude prevalence of diabetes (diagnosed and undiagnosed) in the U.S. was 9.3%, of which 30% was undiagnosed based on fasting plasma glucose (FPG) (3). A further 26% had impaired fasting glucose (IFG). IFG increases the risk of diabetes (4), and both undiagnosed diabetes and IFG are associated with diabetes complications and risk factors (4,5). These prevalence data came from the National Health and Nutrition Examination Survey (NHANES), the only national survey that captures information on diabetes and pre-diabetes from an interview and FPG.In 2005–2006, an oral glucose tolerance test (OGTT) was added to NHANES, which had not been performed since NHANES 1988–1994. Whereas elevated FPG is determined more by impaired hepatic insulin resistance, elevated 2-h plasma glucose from an OGTT is determined predominantly by peripheral insulin resistance (4,6). The OGTT aids in detecting the total burden of diabetes and also impaired glucose tolerance (IGT). Two-hour plasma glucose values are more sensitive in the elderly (7), an increasing proportion of the U.S. population. IGT also predicts diabetes and is more commonly associated with cardiovascular disease risk factors and events than IFG (4,8).In this report, we analyze the prevalence of diagnosed diabetes, undiagnosed diabetes based on fasting and 2-h plasma glucose from an OGTT, and pre-diabetes (IFG or IGT) in people aged ≥12 years using data from NHANES 2005–2006. Results are presented by age, sex, and race/ethnicity. We compare these estimates with those from NHANES 1988–1994.The addition of the OGTT also allowed assessment of the agreement between diagnostic categories defined by fasting and 2-h plasma glucose. Although this was examined in NHANES 1988–1994 in those aged 40–74 years (9), a reexamination is appropriate given 1) the measurements in a wider age range in NHANES 2005–2006, 2) the change in criteria for IFG (lowered from 110 to 100 mg/dl) since that report (8), and 3) the rising prevalence of glucose abnormalities (3) and obesity (10).     

The significance of impaired fasting glucose versus impaired glucose tolerance: importance of insulin secretion and resistance

OBJECTIVE: The American Diabetes Association recommended substituting 2hBS (glycemia at the second hour of an oral glucose tolerance test [OGTT]) for fasting blood glucose (FBS) in screening for glucose intolerance. It is debated whether these tests measure the same abnormality and relate to defective insulin secretion or resistance. This study examines the diagnostic effectiveness of FBS versus 2hBS and their relationship with insulin secretion and resistance. RESEARCH DESIGN AND METHODS: Based on history or physical findings suggesting glucose intolerance, we enrolled 398 unselected subjects admitted to a general Internal Medicine ward. After 5 days of a weight-maintaining diet, FBS, 2hBS, and insulin were measured during OGTT. The homeostatic model assessment was used to assess beta-cell function and insulin resistance. RESULTS: Excluding 19 patients with diabetes (5%), we identified 284 subjects with normal glucose tolerance (NGT), 22 with isolated impaired fasting glucose (IFG), 59 with isolated impaired glucose tolerance (IGT), and 14 with associated IFG/IGT. The sensitivity of FBS in predicting 2hBS was 19%, specificity 93%. Positive and negative predictive values were 39% and 83%, respectively. Insulin resistance was absent in NGT and IFG and markedly elevated in IGT and IFG/IGT, whereas defective insulin release was significant only in isolated IFG. CONCLUSIONS: In unselected patients, elevated FBS depends primarily on defective insulin secretion, and impaired 2hBS on insulin resistance. Because these tests measure different alterations, they are useful in combination.     

Postpartum Diabetes Screening: Adherence rate and the performance of fasting plasma glucose versus oral glucose tolerance test

OBJECTIVE

To determine the rate of adherence to postpartum glycemic testing in women with gestational diabetes mellitus (GDM) and the performance of fasting plasma glucose (FPG) versus the 75-g oral glucose tolerance test (OGTT) in detecting postpartum glucose intolerance.

RESEARCH DESIGN AND METHODS

The study was a retrospective cohort of 1,006 women with GDM attending a pregnancy diabetes clinic.

RESULTS

Postpartum screening was completed in 438 (48%) women. Women nonadherent to testing had higher parity (1.10 vs. 0.87) and were less likely to require insulin for management of their GDM. Among women who were tested, 89 (21%) had an abnormal result, only 25 (28%) of whom were identified by FPG. Factors associated with abnormal postpartum diabetes screening include non-Caucasian ethnicity, previous GDM, higher A1C, and OGTT values during pregnancy and treatment with insulin.

CONCLUSIONS

The rate of postpartum diabetes screening is low, and FPG lacks sensitivity as a screening test in comparison with OGTT.Gestational diabetes mellitus (GDM) strongly predicts future development of type 2 diabetes (1), and abnormal glucose tolerance can persist postpartum leading to impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes (2). Compared with an oral glucose tolerance test (OGTT), fasting plasma glucose (FPG) has greater reproducibility but may lack sensitivity to identify women with IGT or type 2 diabetes (3–5). The main study objectives were to assess adherence with postpartum testing, to identify factors associated with nonadherence, and to compare the sensitivity of FPG versus a 75-g OGTT in detecting postpartum glucose intolerance.     

Impaired fasting glucose or impaired glucose tolerance. What best predicts future diabetes in Mauritius?

OBJECTIVE: To determine if impaired fasting glucose (IFG; fasting plasma glucose level 6.1-6.9 mmol/l) can predict future type 2 diabetes as accurately as does impaired glucose tolerance (IGT; 2-h plasma glucose level 7.8-11.0 mmol/l). RESEARCH DESIGN AND METHODS: A longitudinal population-based study was performed with surveys in 1987 and 1992 on the island of Mauritius, assessing diabetes status by the oral glucose tolerance test. A total of 3,717 subjects took part in both surveys. Of these subjects, 3,229 were not diabetic in 1987 and formed the basis of this study. RESULTS: At baseline, there were 607 subjects with IGT and 266 subjects with IFG. There were 297 subjects who developed diabetes by 1992. For predicting progression to type 2 diabetes, the sensitivity, specificity, and positive predictive values were 26, 94, and 29% for IFG and 50, 84, and 24% for IGT, respectively. Only 26% of subjects that progressed to type 2 diabetes were predicted by their IFG values, but a further 35% could be identified by also considering IGT. The sensitivities were 24% for IFG and 37% for IGT in men and 26% for IFG and 66% for IGT in women, respectively. CONCLUSIONS: These data demonstrate the higher sensitivity of IGT over IFG for predicting progression to type 2 diabetes. Screening by the criteria for IFG alone would identify fewer people who subsequently progress to type 2 diabetes than would the oral glucose tolerance test.     

Should oral glucose tolerance testing be mandatory following acute myocardial infarction?

A high prevalence of newly detected diabetes mellitus (DM) and impaired glucose tolerance (IGT) has been reported in patients with acute myocardial infarction (AMI) and no previous diagnosis of DM. However, the prevalence of newly detected DM is grossly underestimated by using fasting plasma glucose (FPG). We determined the prevalence of DM and IGT in patients post-AMI from our local mixed ethnicity population, and evaluated the usefulness of oral glucose tolerance testing in such patients. All non-diabetic subjects admitted with AMI underwent a standardised oral glucose tolerance test (OGTT) with 75 g glucose load predischarge in our institution. Fasting and 2-h postchallenge plasma glucose levels were recorded, in addition to admission plasma glucose, serum cholesterol, triglycerides, HDL cholesterol and haemoglobin A1(C)levels. We studied 61 patients [38 (62%) male; mean (SD) age, 64 (12.5) years], of whom 70% were white European and 30% South Asians. Mean (SD) plasma glucose concentration on admission was 6.9 (1.7; range, 5.8-8.1) mmol/l. Newly diagnosed DM and IGT were detected in 31% (95% CI 10-52) and 33% (95% CI 12-53) of patients respectively. Of those with newly detected diabetes only 32% (95% CI 0-69) had FPG > 6.1 mmol/l. The 12 month major adverse cardiac event rate was 4.5%, 15% and 32% in those with normal glucose tolerance, IGT and DM respectively. Previously undiagnosed DM and IGT in patients with AMI is common. The false reassurance of a normal FPG denies a significant proportion of undiagnosed diabetics the chance of early treatment. The importance of OGTT in the diagnostic work up of this vulnerable high-risk group cannot be over-emphasised.     

老年高血压患者血糖与颈动脉内膜中层厚度及动脉弹性的相关性

摘要 目的 探讨老年高血压患者血糖变化对颈动脉内膜中层厚度和动脉弹性的影响是否有叠加作用。方法 82例老年高血压患者根据糖耐量试验分成糖耐量正常组（NGT组）、空腹血糖受损组（IFG组）、糖耐量减低组（IGT组）和糖尿病组（DM组），26例健康体检者作为对照组（NC组）。通过超声检测颈动脉内膜中层厚度（IMT），用动脉硬化检测仪测量颈-股动脉脉搏波的传导速度（PWV）。结果 老年高血压患者IMT、PWV显著高于健康对照者。由NGT组到IFG组、IGT组、DM组，IMT、PWV逐渐增加，IFG组IGT组间无显著性差异。在无血糖紊乱的情况下，脉压和年龄是影响IMT、PWV的主要因素。当存在糖代谢异常时，糖化血红蛋白、餐后2小时血糖可影响IMT、PWV。结论 老年高血压患者，IMT增厚，动脉弹性降低。血糖代谢异常加重了老年高血压患者IMT增厚及动脉弹性的减退，使其心血管并发病的风险加大。     

不同年龄段的正常糖耐量人群血糖值及其相关因素分析

目的 分析不同年龄段正常糖耐量(NGT)者血糖水平及相互关系.方法 选择上海市杨浦区部分街道流行病学调研2098例30岁以上居民,根据糖耐量(OGTT)检测中空腹血糖值(FPG)和2 h血糖值(2 hPG),诊断为NGT、糖耐量低减(IGT)、空腹血糖受损(IFG)、IGT合并IFG(IGT/IFG)、糖尿病(DM),将NGT者按年龄分成5组,观察各年龄组的血糖水平,用稳态模式分析胰岛β细胞功能指数(HBCI),并对其进行统计学分析.结果 在NGT中60～69年龄组FPG值(5.17±0.48)mmol/L、糖化血红蛋白(HbA1c)(6.01±0.62)%较50～59年龄组FPG值(5.09±0.44)mmol/L、HbA1c值(5.95±0.66)%高(t值分别为2.06、2.48,P均<0.05).60～69年龄组FIG值较40～49年龄组FPG值(5.01±0.47)mmol/L高(t=2.26,P<0.01),50～59年龄组FPG值较40～49年龄组高(t=2.48,P<0.01),5组按年龄从小至大比较,空腹胰岛素(FINS)值变化无明显规律;60岁以上HBCI较60岁以下的HBCI值下降,差异有统计学意义(F值为33.75,P<0.01).结论 NGT人群随着年龄的增长,FPG、HbAlc可能增高.

Abstract：

Objective To compare the glucose levels and associated factors among the normal glucose tolerance subjects with different age.Methods Totally a community-based population of 2098 residences aged above 30 years Were tested with OGTT,and classified into normal glucose tolerance group(NGT),impaired glucose tolerance group(IGT),impaired fasting glucose group(IFG),both IGT and IFG group(ICT/IFC),anddiabetes group(DM) according to fasting and 2 hours glucose level(2 hPG).The subjects in NGT group were further divided into 5 groups according to different ages.The levels of blood glucose and HBCI in different groups and subgroups were measured and analyzed statistically. Results For patients in NGT,the FPG([5.17.±0.48]mmol/L vs.[5.09±0.44]mmol/L,P<0.05)and HbA1c([6.01±0.62]%vs.[5.95±0.66]%.P<0.05)in group aged 60-69 Were higher than that in group aged 50-59.The FPG in group aged 60-69 was also higher than those in group aged 40-49([5.17±0.48]mmol/L vs.[5.00±0.47]mmol/L,P<0.01),and the FPG in group aged 50-59 Was also higher than those in group aged 40-49([5.09±0.44]mmol/L vs..[5.00±0.47]mmol/L,P<0.01).There was no correlation between age and FINS,while a tendency of decreasing HBCI could be observed along with increasing of age(F=33.75,P<0.05).Conclusion In NGT subjects,the FPG and HbA1 C inereased along with age.