Evaluation of the relationship between capillary and venous plasma glucose concentrations obtained by the HemoCue Glucose 201+ system during an oral glucose tolerance test

In 55 women with previous gestational diabetes mellitus, simultaneous capillary and venous plasma glucose concentrations were measured at 0, 30 and 120 min during a 75 g oral glucose tolerance test (OGTT). The aims of the study were to examine the relationship between capillary and venous glucose measurements, and to establish equations for the conversion of capillary and venous glucose concentrations using the HemoCue Glucose 201+ system. Additionally, the correlation between the capillary and venous glucose concentrations with the diagnostic cut-off limits proposed by the World Health Organization (WHO) in 1999 was evaluated. Capillary glucose concentrations were consistently higher than venous glucose concentrations at all time points of the OGTT (p < 0.001), and the correlations between the measurements were statistically highly significant (p < 0.001). The differences between the samples were greatest in the non-fasting state as revealed by the 95% prediction intervals (mmol/L) in Bland-Altman plots; ± 0.54 at 0 min, ± 2.01 at 30 min, and ± 1.35 at 120 min. Equivalence values for capillary plasma glucose concentrations derived from this study tended to be higher than those proposed by the WHO as diagnostic cut-off limits. Stratifying subjects by glucose tolerance status according to the WHO criteria revealed disagreements related to glucose values close to the diagnostic cut-off points. The study findings highlight the uncertainty associated with derived equivalence values. However, capillary plasma glucose measurements could be suitable for diagnostic purposes in epidemiological studies and when translating results on a group basis.     

Evaluation of the relationship between capillary and venous plasma glucose concentrations obtained by the HemoCue Glucose 201+ system during an oral glucose tolerance test

Abstract

In 55 women with previous gestational diabetes mellitus, simultaneous capillary and venous plasma glucose concentrations were measured at 0, 30 and 120 min during a 75 g oral glucose tolerance test (OGTT). The aims of the study were to examine the relationship between capillary and venous glucose measurements, and to establish equations for the conversion of capillary and venous glucose concentrations using the HemoCue Glucose 201+ system. Additionally, the correlation between the capillary and venous glucose concentrations with the diagnostic cut-off limits proposed by the World Health Organization (WHO) in 1999 was evaluated. Capillary glucose concentrations were consistently higher than venous glucose concentrations at all time points of the OGTT (p < 0.001), and the correlations between the measurements were statistically highly significant (p < 0.001). The differences between the samples were greatest in the non-fasting state as revealed by the 95% prediction intervals (mmol/L) in Bland-Altman plots; ± 0.54 at 0 min, ± 2.01 at 30 min, and ± 1.35 at 120 min. Equivalence values for capillary plasma glucose concentrations derived from this study tended to be higher than those proposed by the WHO as diagnostic cut-off limits. Stratifying subjects by glucose tolerance status according to the WHO criteria revealed disagreements related to glucose values close to the diagnostic cut-off points. The study findings highlight the uncertainty associated with derived equivalence values. However, capillary plasma glucose measurements could be suitable for diagnostic purposes in epidemiological studies and when translating results on a group basis.     

Risk of progression to type 2 diabetes based on relationship between postload plasma glucose and fasting plasma glucose

OBJECTIVE: We sought to assess the risk of progression to type 2 diabetes in normal glucose tolerance (NGT) subjects based on the relationship between the plasma glucose concentration during oral glucose tolerance tests (OGTTs) and the fasting plasma glucose (FPG) concentration. RESEARCH DESIGN AND METHODS: Subjects with NGT (n = 1,282) from the San Antonio Heart Study received an OGTT with measurement of the plasma glucose concentration at 0, 30, 60, and 120 min at baseline and after 7-8 years of follow-up. Subjects were divided into four groups based on the relationship between the plasma glucose concentration during the OGTT and the FPG concentration on the same day as the OGTT. Insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index. Early-phase insulin secretion was calculated as the ratio between the incremental plasma insulin and glucose concentrations during the first 30 min of the OGTT (DeltaI(0-30)/DeltaG(0-30)). Total insulin secretion was calculated as the ratio between the incremental areas under the insulin and glucose curves during the OGTT [DeltaG(AUC)/DeltaI(AUC)]. RESULTS: In 23 subjects (group I), the plasma glucose concentration during the OGTT returned to levels below the FPG concentration at 30 min; in 111 subjects (group II) and in 313 subjects (group III), the plasma glucose concentration during the OGTT returned to levels below the FPG concentration at 60 and 120 min, respectively. In the remaining 835 subjects (group IV), the plasma glucose concentration during the OGTT never fell below the FPG concentration. Insulin resistance, measured by HOMA-IR and the Matsuda index, increased progressively from group I through group IV, while insulin secretion measured by DeltaI(0-30)/DeltaG(0-30) and DeltaG(AUC)/DeltaI(AUC) decreased progressively from group I through group IV. The incidence of type 2 diabetes was 0% in group I and progressively increased to 0.9% in group II, 3.2% in group III, and 6.4% in group IV. CONCLUSIONS: Subjects whose postload plasma glucose concentration returned to baseline (i.e., FPG level) more quickly had greater insulin sensitivity, a higher insulinogenic index, and a lower risk of developing type 2 diabetes after 8 years of follow-up compared with subjects whose postload glucose concentration returned to baseline more slowly.     

Detecting type 2 diabetes by a single post-challenge blood sample.

In the recent American Diabetes Association (ADA)/WHO recommendations, the oral glucose tolerance test (OGTT) was replaced by the measurement of a single fasting glucose concentration with a decision limit for the detection of type 2 diabetes mellitus (DM) reduced. This proposal, however, misses all cases of isolated post-prandial hyperglycaemia. Therefore, a study was undertaken to develop a post-challenge, one-sample mode of diagnosis. OGTT was performed in 240 high-risk subjects who were suspected to suffer from type 2 DM. Glucose concentrations were determined at 30 min intervals in the capillary blood, venous blood and plasma, and insulin was determined in venous plasma only. The test results were classified in non-disease and disease group according to the decision limits recommended by ADA/WHO. Furthermore, the early insulin response and an insulin sensitivity index were used to determine new cut-off values. These were identified as the concentrations demonstrating the highest diagnostic efficiency and were lower than the WHO limits. The 2 h post-load plasma concentration led to higher efficiency at a cut-off value of 9.0 mmol/l glucose (162 mg/dl) compared to concentrations of samples taken in the fasting state, at an earlier time of the OGTT, or in venous and capillary blood. Under this condition, 72 diabetic patients (35%) were detected in the study group (n = 207), whereas only 36 (17%) were found with one sample in the fasting state and 53 (26%) with two samples using the ADA/WHO criteria. Therefore, a single venous plasma sample taken after 2 h post-glucose challenge appeared to be most efficient for the early detection of DM.     

Diagnosis of impaired glucose tolerance in hypertensive patients in daily clinical practice

Many patients with hypertension suffer from impaired glucose tolerance or type 2 diabetes mellitus. Although these diagnoses are generally simple and reliable, it is more difficult to diagnose impaired glucose tolerance. As the gold standard (oral glucose tolerance test (OGTT)) is complicated to perform, a simpler alternative would be useful. The aims of the Pre-Diabetes Score study are to correlate demographic and/or laboratory parameters that are clinically simple to determine with the results of the OGTT and to determine the diagnostic significance of the combinations of parameters with regard to impaired glucose tolerance. A total of 260 patients were included in the evaluation; 39% had impaired glucose tolerance and 12% had diabetes mellitus. A combination of HbA1c of > or =6%, a venous fasting glucose of > or =110 mg/dl, an age of > or =55 years, a systolic blood pressure of > or =140 mmHg and an enlarged waist size is highly predictive of impaired glucose tolerance.     

One-hour plasma glucose concentration and the metabolic syndrome identify subjects at high risk for future type 2 diabetes

OBJECTIVE—To assess the efficacy of 1-h plasma glucose concentration and the metabolic syndrome in predicting future risk of type 2 diabetes.RESEARCH DESIGN AND METHODS—A total of 1,611 subjects from the San Antonio Heart Study, who were free of type 2 diabetes at baseline; who had plasma glucose and insulin concentrations measured at time 0, 30, 60, and 120 min during the oral glucose tolerance test (OGTT); and who had their diabetes status determined with an OGTT after 7–8 years of follow-up, were evaluated. Two models, based on glucose tolerance status, 1-h plasma glucose concentration, and presence of the metabolic syndrome, were tested in predicting the risk for type 2 diabetes at 7–8 years of follow-up.RESULTS—A cutoff point of 155 mg/dl for the 1-h plasma glucose concentration during the OGTT was used to stratify subjects in each glucose tolerance group into low, intermediate, and high risk for future type 2 diabetes. A model based upon 1-h plasma glucose concentration, Adult Treatment Panel (ATP) III criteria for the metabolic syndrome, and fasting plasma glucose, independent of 2-h plasma glucose, performed equally well in stratifying nondiabetic subjects into low, intermediate, and high risk for future type 2 diabetes and identified a group of normal glucose-tolerant subjects who were at very high risk for future type 2 diabetes.CONCLUSIONS—The plasma glucose concentration at 1 h during the OGTT is a strong predictor of future risk for type 2 diabetes. A plasma glucose cutoff point of 155 mg/dl and the ATP III criteria for the metabolic syndrome can be used to stratify nondiabetic subjects into three risk groups: low, intermediate, and high risk.Clinical trials have demonstrated that lifestyle intervention and pharmacological therapy in high-risk individuals reduce the incidence of type 2 diabetes (1). Thus, reliable models for identification of individuals at high risk for future type 2 diabetes are essential and have important clinical implications for intervention programs. Subjects with impaired glucose tolerance (IGT) are at increased risk for future type 2 diabetes (2), and the oral glucose tolerance test (OGTT) has become the standard method for identifying individuals at risk for type 2 diabetes. Indeed, all clinical trials that have assessed strategies for type 2 diabetes prevention have recruited subjects with IGT. Although IGT subjects have increased risk for type 2 diabetes, only ∼50% convert to type 2 diabetes within 10 years of follow-up (2), indicating that the future risk for diabetes is not similar among all individuals with IGT. Furthermore, in longitudinal epidemiological studies, ∼40% of subjects who develop type 2 diabetes have normal glucose tolerance (NGT) at baseline, indicating that there is a population of NGT subjects who are at risk for future type 2 diabetes (2). Recently, we demonstrated that subjects with NGT, despite having relatively low risk for type 2 diabetes, can be stratified into low- and high-risk categories based upon the relationship between their postload and fasting plasma glucose (FPG) concentrations (3).Several models have been proposed to improve the predictive ability for future type 2 diabetes (4–7). These models are based upon established risk factors for type 2 diabetes (e.g., obesity, FPG, lipid profile, and blood pressure). All of these risk factors are components of the metabolic or insulin resistance syndrome, which is itself a predictor of future type 2 diabetes in nondiabetic individuals (8). In a recent publication (9), we demonstrated that the 1-h plasma glucose concentration is a better predictor for future type 2 diabetes than either the FPG or 2-h plasma glucose concentration. Furthermore, the addition of the 1-h plasma glucose concentration to a prediction model based on clinical parameters significantly improved the ability of the model to predict future type 2 diabetes (9). In this study, we have used the classification tree model (10) to stratify the risk for future type 2 diabetes in nondiabetic subjects based upon their 1-h plasma glucose concentration during the OGTT and the Adult Treatment Panel (ATP) III criteria for the metabolic syndrome. We demonstrate that a model based on the combination of 1-h plasma glucose concentration during the OGTT and the ATP III criteria for the metabolic syndrome improves the ability to predict the future risk for type 2 diabetes.     

Prevalence-dependent decision limits for the early detection of type 2 diabetes mellitus in venous blood, venous plasma and capillary blood during glucose challenge.

BACKGROUND: The glycemia decision limits recommended by WHO/ADA for type 2 diabetes detection are derived from clinical signs in advanced stages of the disease. Since insulin secretion patterns and sensitivitity are impaired at the beginning of type 2 diabetes, this stage may be better suited to identify decision limits with higher diagnostic efficiency than those currently applied. METHODS: Oral glucose tolerance tests were performed in 300 subjects. Glucose concentrations were measured at 30-min intervals in venous plasma, venous blood and capillary blood. Insulin concentrations in venous plasma, an insulin sensitivity index and body mass index were used to indicate a type 2 diabetic state. A multiple logistic regression procedure was "trained" using only subjects "clearly" considered to be non-diseased or diseased based on an oral glucose tolerance test according to WHO criteria. This insulin algorithm was applied to the whole study group, leading to definitive classification into the non-diseased or the diseased group. This a posteriori classification was used to identify cutoff values with the highest diagnostic efficiency. RESULTS: The diagnostic efficiency was significantly higher when decision limits lower than the WHO recommendations for glucose concentrations were applied in a preselected subpopulation and in all three sample systems tested, e.g., 9.49 mmol/L (171 mg/dL) for venous plasma and 8.94 mmol/L (161 mg/dL) for capillary blood in the 2-h post-load state. The optimized and WHO 2-h cutoff values corresponded to a disease prevalence of 28% and approximately 5% (20% in the fasting state), respectively. Diagnostic efficiency was higher in the 2-h post-load than in the fasting state. Combining fasting values with 2-h post-load values did not further improve the diagnostic efficiency. Glucose concentrations determined from capillary blood were as efficient as those from venous blood or plasma. The number of diabetic subjects detected differed considerably between capillary blood and venous plasma for the WHO/ADA cutoff values, but not for the optimized cutoff values. CONCLUSIONS: The efficiency of type 2 diabetes diagnosis can be improved by optimizing cutoff values according to disease prevalence. Unexpectedly, the optimized 2-h post-load cutoff was lower for capillary blood than for venous plasma. It is proposed to identify a risk group e.g., by characteristics of the metabolic syndrome in which the 2-h post-challenge concentration is determined using lower cut-off values than presently recommended.     

The prevalence of diabetes and impaired glucose tolerance in Sivas, Central Anatolia, Turkey

OBJECTIVE: The aim of this study was to determine type 2 diabetes, impaired glucose tolerance (IGT), and impaired fasting glucose (IFG) prevalence in Sivas, Turkey. RESEARCH DESIGN AND METHODS: This cross-sectional study was conducted in the city center of Sivas. The study population of 771 subjects was selected by the cluster sampling method from 115,998 individuals aged > or =30 years. Participants with fasting venous plasma glucose concentrations <100 mg/dl were classified as "normal." Diabetes was diagnosed in participants if they had fasting blood glucose levels > or =126 mg/dl. An oral glucose tolerance test (OGTT) was performed in subjects with fasting blood glucose levels > or =100 mg/dl and <126 mg/dl. RESULTS: According to the fasting blood glucose levels of the 771 subjects, 44 (5.7%) had diabetes. OGTTs were performed in 80 (10.4%) subjects. According to OGTT results, there were 5 subjects with diabetes, 20 subjects with IGT (2.6%), and 55 subjects with IFG (7.1%). The combined prevalence of IFG and IGT was 9.7%. After OGTT, the total number of diabetic subjects was determined to be 49 (6.4%). Twenty-four (3.1%) of the subjects had a previous diagnosis of diabetes. Multivariate analyses showed that age, sex, hypertension, cigarette smoking, obesity, and family history of diabetes were risk factors for type 2 diabetes (P < 0.05). CONCLUSIONS: Diabetes incidence increases with changes in dietary habits and lifestyle. Education is particularly important for public health, as the community may then have required knowledge about the disease and its risk factors.     

A model-based method for assessing insulin sensitivity from the oral glucose tolerance test

OBJECTIVE: Available insulin sensitivity (IS) methods based on the oral glucose tolerance test (OGTT) are empirical. We used a glucose-insulin model to derive an OGTT-based IS (oral glucose insulin sensitivity [OGIS]) index, which predicts glucose clearance in a glucose clamp. We validated OGIS against clamp data. RESEARCH DESIGN AND METHODS: OGIS requires glucose and insulin concentrations from a 75-g OGTT at 0, 2, and 3 h (3-h OGTT) or at 0, 1.5, and 2 h (2-h OGTT). The formula includes six constants optimized to match the clamp results. For this purpose, 15 lean nondiabetic subjects (BMI < 25 kg/m2), 38 obese nondiabetic subjects (BMI > 25 kg/m2), and 38 subjects with type 2 diabetes randomly underwent an OGTT and a 120 mU x min(-1) x m(-2) insulin infusion euglycemic clamp. Glucose clearance (Cl CLAMP), calculated as the ratio of glucose infusion to concentration during the last hour of the clamp, was compared with OGIS. OGIS was also tested on an independent group of 13 subjects with impaired glucose tolerance (IGT). RESULTS: OGIS and Cl CLAMP were correlated in the whole group (R = 0.77, P < 0.0001), in the subgroups (lean: R = 0.59; obese: R = 0.73; type 2 diabetes: R = 0.49; P < 0.02), and in the independent IGT group (R = 0.65, P < 0.02). Reproducibility of OGIS and Cl CLAMP were similar (coefficients of variation: OGIS 7.1%, Cl CLAMP 6.4%). OGIS was as effective as Cl CLAMP in discriminating between groups (for OGIS, lean vs. obese: 440 +/- 16 vs. 362 +/- 11 ml x min(-1) x m(-2), p < 0.001; lean vs. type 2 diabetes: 440 +/- 16 vs. 239 +/- 7, P < 0.0001; obese vs. type 2 diabetes: 362 +/- 11 vs. 239 +/- 7, P < 0.0001; results were similar for Cl CLAMP). The relationships between IS and BMI, fasting plasma insulin, and insulin secretion (calculated from the OGTT insulin concentration) were examined. OGIS yielded results similar to Cl CLAMP and fully consistent with established physiological principles. The performance of the index for the 3-h and 2-h OGTT was similar. CONCLUSIONS: OGIS is an index of IS in good agreement with the clamp. Because of its simplicity (only three blood samples required), this method has potential use for clinical investigation including large-scale epidemiological studies.     

Acute fructose administration improves oral glucose tolerance in adults with type 2 diabetes.

OBJECTIVE: In normal adults, a small (catalytic) dose of fructose administered with glucose decreases the glycemic response to a glucose load, especially in those with the poorest glucose tolerance. We hypothesized that an acute catalytic dose of fructose would also improve glucose tolerance in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: Five adults with type 2 diabetes underwent an oral glucose tolerance test (OGTT) on two separate occasions, at least 1 week apart. Each OGTT consisted of 75 g glucose with or without the addition of 7.5 g fructose (OGTT + F or OGTT - F), in random order. Arterialized blood samples were collected from a heated dorsal hand vein twice before ingestion of the carbohydrate and every 15 min for 3 h afterward. RESULTS: The area under the curve (AUC) of the plasma glucose response was reduced by fructose administration in all subjects; the mean AUC during the OGTT + F was 14% less than that during the OGTT - F (P < 0.05). The insulin AUC was decreased 21% with fructose administration (P = 0.2). Plasma glucagon concentrations declined similarly during OGTT - F and OGTT + F. The incremental AUC of the blood lactate response during the OGTT - F was approximately 50% of that observed during the OGTT + F (P < 0.05). Neither nonesterified fatty acid nor triglyceride concentrations differed between the two OGTTs. CONCLUSIONS: Low-dose fructose improves the glycemic response to an oral glucose load in adults with type 2 diabetes, and this effect is not a result of stimulation of insulin secretion.     

Measurement of glucose content in plasma from capillary blood in diagnosis of diabetes mellitus

Overall, there is good correlation between glucose values obtained from ear capillary blood and those from peripheral venous plasma, but there are considerable individual differences. Results obtained with these two methods are generally not interchangeable and the converted values should not be used in the diagnosis of diabetes mellitus, because of the risk of misclassification. In Denmark this can affect 20-24000 persons. The aim of our study was to investigate whether these differences might be less significant if measurements were taken at the plasma phase of capillary blood and expressed directly as capillary plasma results and if finger capillary blood were used instead of ear capillary blood. The Hitachi 717 instrument was used for measurements of glucose concentrations in venous plasma, the Cobas Mira S in capillary whole blood and the Accu-Chek Inform from Roche in capillary plasma. The conclusions drawn were (1) capillary ear blood glucose concentration correlates well with capillary finger blood concentration and the two sites can be used interchangeably, yielding similar results in the individual patient; (2) sampling variation is almost the same (approx. 0.16 mmol/L) on capillary plasma and capillary whole blood from finger and ear. Sampling variation for venous plasma measured on the Hitachi instrument was 0.13 mmol/L; not significantly better; (3) the analytical imprecision of glucose measurements on capillary plasma (Accu-Chek Inform) and capillary whole blood (haemolysate method) is almost the same (approx. 2.0%). The analytical imprecision of glucose measurements on venous plasma is 0.9% using a laboratory method and almost twice as high using Accu-Chek Inform (2.1%); (4) determination of capillary plasma values in the finger did not improve the correlation with venous plasma values. Even though average values were in better concordance, individual differences did not change. For some persons, both ear- and finger capillary blood measurements deviate significantly from results on venous plasma, such that they cannot be used for diagnosis of diabetes mellitus; (5) the main factor for good correlation is the sampling site. Results obtained on plasma and whole blood from the same puncture correlate well; (6) neither capillary blood nor capillary plasma correlates with the venous plasma method recommended by the American Diabetes Association. It is concluded that physiologic differences in glucose content in capillary- and venous blood prohibit the random use of these two materials in the diagnosis of diabetes.     

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.     

Are spouses of patients with type 2 diabetes at increased risk of developing diabetes?

OBJECTIVE: To determine whether spouses of patients with type 2 diabetes have an increased risk of diabetes compared with spouses of subjects with normal glucose tolerance. RESEARCH DESIGN AND METHODS: A random sample of spouses of patients with type 2 diabetes (group 1S) attending a general practice diabetes clinic was compared with spouses of nondiabetic subjects (as determined by oral glucose tolerance test [OGTT]) (group 2S). Spouses in both groups underwent OGTT, fasting lipid profile, and blood pressure (BP) measurements. RESULTS: A total of 245 subjects in group 1S and 234 subjects in group 2S underwent OGTT. Group 1S had a significantly higher incidence of fasting glucose, impaired glucose tolerance, or type 2 diabetes (19.1 vs. 9.4%). Group 1S also had higher fasting glucose and triglyceride levels, higher BMI, and a trend toward higher BP. Multivariate logistic regression analysis, adjusted for BMI and age, showed the risk of diabetes in the spouse of a patient with diabetes was 2.11 (95% CI 1.74-5.1), as compared with the spouse of a subject with normal glucose tolerance. Similarly, the risk of any degree of glucose intolerance in a spouse of a patient with type 2 diabetes was 2.32 (1.87-3.98), as compared with a spouse of a subject with normal glucose tolerance. CONCLUSIONS: Spouses of patients with type 2 diabetes have a significantly increased risk of glucose intolerance and type 2 diabetes, and they should be classified as high risk for diabetes. This finding has implications for screening programs, which should include spouses of subjects with diabetes.     

不同糖耐量人群血清C反应蛋白水平

目的:比较不同糖耐量人群血清C反应蛋白(CRP)水平。方法:92例受试者行口服75g葡萄糖耐量试验(OGTT),确定糖耐量正常(NGT)30例,IGT43例,新诊断2型糖尿病19例,测定血清CRP。结果:NGT、IGT、新诊断的2型糖尿病人群中,血清CRP水平逐渐升高,血清CRP水平与OGTT2h血糖、总胆固醇、甘油三酯呈正相关。结论:随着糖耐量受损的加重,血清CRP水平逐渐升高;血清CRP水平与OGTT2h血糖、总胆固醇、甘油三酯呈正相关。     

Predictive value of first fasting plasma glucose compared with admission plasma glucose for undiagnosed diabetes in a stable cardiology population

ObjectivesThe study compared the predictive value of admission plasma glucose (APG) and first fasting plasma glucose (FPG) in stratifying patients meriting an oral glucose tolerance test (OGTT).Design and methodsCharacteristics of APG, FPG and OGTT 2-hour glucose as well as other blood measurements, physical examinations and medical information were assessed in 994 patients without known diabetes.ResultsThe prevalences of diabetes and impaired glucose tolerance were 24.6% and 37.9%, according to an OGTT, respectively. The first FPG demonstrated stronger predictive value in diagnosing diabetes than APG did both in overall and in patients with less clinical value. Compared to the first FPG, APG provided less value to coronary artery disease, hypertension and high-sensitivity C-reactive protein for diabetes screening.ConclusionsThe first FPG exerted more predictive value than APG did and was still a preferable reference prior to APG in stratifying patients for undiagnosed diabetes by an OGTT.     

糖尿病和糖耐量异常患者在急性缺血性脑血管病中的调查研究

目的 探讨糖尿病和糖耐量异常患者在急性缺血性脑血管病中的流行情况.方法 选择急诊内科病房及神经内科住院的115例短暂性脑缺血发作(TIA)、496例急性脑梗死患者进行空腹血糖、糖化血红蛋白检测,登记患者的临床资料,对既往未诊断糖尿病而空腹血糖在6.1～6.9 mmol/L的患者中进行口服葡萄糖耐量试验(OGTT),糖代谢分类采用2003年美国糖尿病学会建议标准.结果 611例急性缺血性脑血管病患者住院前糖尿病的诊断率18.8%,住院后系统检查发现糖尿病新的患病率45.0%,糖耐量异常18.6%;212例空腹血糖在6.1～6.9 mmol/L的患者中,OGTT发现其中33.5%患者可诊断为糖尿病,53.8%提示糖耐量异常.结论 63.8%的急性缺血性脑血管病患者合并糖尿病或糖耐量异常;空腹血糖在6.1～6.9 mmol/L的患者应常规做OGTT检查来筛查糖代谢异常患者.     

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.     

Insulin sensitivity indices obtained from oral glucose tolerance testing: comparison with the euglycemic insulin clamp.

OBJECTIVE: Several methods have been proposed to evaluate insulin sensitivity from the data obtained from the oral glucose tolerance test (OGTT). However, the validity of these indices has not been rigorously evaluated by comparing them with the direct measurement of insulin sensitivity obtained with the euglycemic insulin clamp technique. In this study, we compare various insulin sensitivity indices derived from the OGTT with whole-body insulin sensitivity measured by the euglycemic insulin clamp technique. RESEARCH DESIGN AND METHODS: In this study, 153 subjects (66 men and 87 women, aged 18-71 years, BMI 20-65 kg/m2) with varying degrees of glucose tolerance (62 subjects with normal glucose tolerance, 31 subjects with impaired glucose tolerance, and 60 subjects with type 2 diabetes) were studied. After a 10-h overnight fast, all subjects underwent, in random order, a 75-g OGTT and a euglycemic insulin clamp, which was performed with the infusion of [3-3H]glucose. The indices of insulin sensitivity derived from OGTT data and the euglycemic insulin clamp were compared by correlation analysis. RESULTS: The mean plasma glucose concentration divided by the mean plasma insulin concentration during the OGTT displayed no correlation with the rate of whole-body glucose disposal during the euglycemic insulin clamp (r = -0.02, NS). From the OGTT, we developed an index of whole-body insulin sensitivity (10,000/square root of [fasting glucose x fasting insulin] x [mean glucose x mean insulin during OGTT]), which is highly correlated (r = 0.73, P < 0.0001) with the rate of whole-body glucose disposal during the euglycemic insulin clamp. CONCLUSIONS: Previous methods used to derive an index of insulin sensitivity from the OGTT have relied on the ratio of plasma glucose to insulin concentration during the OGTT. Our results demonstrate the limitations of such an approach. We have derived a novel estimate of insulin sensitivity that is simple to calculate and provides a reasonable approximation of whole-body insulin sensitivity from the OGTT.     

Assessing the shape of the glucose curve during an oral glucose tolerance test

OBJECTIVE:The oral glucose tolerance test (OGTT) is used to define the status of glucose tolerance based on the plasma glucose level at 120 min. The purpose of the present study was to identify parameters that determine the shape of the plasma glucose course measured at 0, 30, 60, 90, and 120 min during an OGTT. RESEARCH DESIGN AND METHODS: OGTT data from 551 subjects (485 with normal glucose tolerance [NGT] and 66 with impaired glucose tolerance [IGT]) were analyzed. We distinguished between "monophasic," "biphasic," and unclassified glucose shapes. A "shape" index based on the extent and the direction of the plasma glucose change in the second hour allowed us to treat shape as a continuous variable. RESULTS: In the biphasic group, the NGT-to-IGT ratio was slightly higher (173/20 vs. 209/40, P = 0.08) and the male-to-female ratio was lower (60/133 vs. 120/129, P = 0.0003). Subjects with a biphasic shape had significantly lower age, BMI, waist-to-hip ratio (WHR), HbA(1c), plasma glucose, and area under the insulin curve (insulin(AUC)) and a better estimated insulin sensitivity and secretion (using validated indexes) than monophasic subjects (all P < 0.05). By adjusting this shape index for glucose(AUC) (as continuous measure of glucose tolerance), correlations with age, BMI, WHR, HbA(1c), and insulin(AUC) were completely abolished. The adjusted shape index was still higher in female than in male subjects but lower in IGT than in NGT subjects (both P = 0.0003). Finally, we tested common polymorphisms in insulin receptor substrate (IRS)-1, IRS-2, calpain-10, hepatic lipase, and peroxisome proliferator-activated receptor-gamma for association with the shape index. CONCLUSIONS: We conclude that the plasma glucose shape during an OGTT depends on glucose tolerance and sex. In addition, genetic factors seem to play a role. The shape index may be a useful metabolic screening parameter in epidemiological and genetic association studies.     

Reproducibility of S-insulin and B-glucose responses in two identical oral glucose tolerance tests

Recently, the diagnostic criteria for type 2 diabetes mellitus have been changed, but there are disagreements about which measurements should be used. In contrast to the American Diabetes Association (ADA), The World Health Organization (WHO) still recognizes fasting and 2-h glucose concentrations measured on either plasma or whole blood as diagnostic tools. Insulin sensitivity and insulin secretion are both assumed to be involved in the pathogenesis of type 2 diabetes. The oral glucose tolerance test (OGTT) for estimating insulin sensitivity and secretion is increasingly used, e.g. in intervention trials. The objectives of this study were to estimate the coefficients of intra-individual variation (CVw) of blood glucose and serum insulin concentrations from an OGTT as well as indices of insulin sensitivity (HOMA) and insulin secretion (delta insulin30/delta glucose30) derived from this test. Following duplicate OGTTs with a median interval of 13 days (range 1-87 days), the analytical, inter-individual, and intra-individual coefficients of variation were calculated by nested ANOVA. The CVw for fasting blood glucose (7%) was considerably lower than that for 2-h post-load glucose (15%), which was again lower than for the insulin concentrations and indices of insulin sensitivity and secretion. In conclusion, the intra-individual variation is larger for 2-h post-load glucose than for fasting glucose and may question the continued use of the 2-h post-load glucose value in the diagnosis of type 2 diabetes.