A multivariate logistic regression equation to screen for dysglycaemia: development and validation.

AIMS: To develop and validate an empirical equation to screen for dysglycaemia [impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and undiagnosed diabetes]. METHODS: A predictive equation was developed using multiple logistic regression analysis and data collected from 1032 Egyptian subjects with no history of diabetes. The equation incorporated age, sex, body mass index (BMI), post-prandial time (self-reported number of hours since last food or drink other than water), systolic blood pressure, high-density lipoprotein (HDL) cholesterol and random capillary plasma glucose as independent covariates for prediction of dysglycaemia based on fasting plasma glucose (FPG)>or=6.1 mmol/l and/or plasma glucose 2 h after a 75-g oral glucose load (2-h PG)>or=7.8 mmol/l. The equation was validated using a cross-validation procedure. Its performance was also compared with static plasma glucose cut-points for dysglycaemia screening. RESULTS: The predictive equation was calculated with the following logistic regression parameters: P=1+1/(1+e-X)=where X=-8.3390+0.0214 (age in years)+0.6764 (if female)+0.0335 (BMI in kg/m2)+0.0934 (post-prandial time in hours)+0.0141 (systolic blood pressure in mmHg)-0.0110 (HDL in mmol/l)+0.0243 (random capillary plasma glucose in mmol/l). The cut-point for the prediction of dysglycaemia was defined as a probability>or=0.38. The equation's sensitivity was 55%, specificity 90% and positive predictive value (PPV) 65%. When applied to a new sample, the equation's sensitivity was 53%, specificity 89% and PPV 63%. CONCLUSIONS: This multivariate logistic equation improves on currently recommended methods of screening for dysglycaemia and can be easily implemented in a clinical setting using readily available clinical and non-fasting laboratory data and an inexpensive hand-held programmable calculator.     

Diagnostic value of glycated haemoglobin (HbA1c) for the early detection of diabetes in high‐risk subjects

Objective The aim of this study was to assess the validity of fasting plasma glucose (FPG) and/or glycated haemoglobin (HbA_1c) as screening tests for the early detection of diabetes in high‐risk subjects. Methods A total of 392 subjects (149 male and 243 female) with risk factors for diabetes were included. All subjects underwent a 75‐g oral glucose tolerance test and HbA_1c measurement. Receiver operating characteristic curve analysis was used to examine the sensitivity and specificity of FPG and HbA_1c for detecting diabetes, which was defined as a FPG ≥ 7.0 mmol/l or a post‐challenge 2‐h plasma glucose ≥ 11.1 mmol/l. Results The prevalence of newly diagnosed diabetes was 22.4% (n = 88). The current guideline of FPG ≥ 7.0 mmol/l for diabetes screening detected only 55.7% of diabetic subjects. The optimal cut‐off points of HbA_1c and FPG for the diagnosis of diabetes were 6.1% (sensitivity 81.8%, specificity 84.9%) and 6.1 mmol/l (sensitivity 85.2%, specificity 88.5%), respectively. The screening model using FPG ≥ 6.1 mmol/l and/or HbA_1c ≥ 6.1% had sensitivities of 71.6–95.5% and specificities of 77.6–95.7% for detecting undiagnosed diabetes. Conclusions The current American Diabetes Association diagnostic criteria, based only on FPG, are relatively insensitive in the detection of diabetes in high‐risk subjects. The simultaneous measurement of FPG and HbA_1c might be a more sensitive screening tool for identifying high‐risk individuals with diabetes at an early stage.     

Impaired glucose regulation,elevated glycated haemoglobin and cardiac ischaemic events in vascular surgery patients

Aims Cardiac morbidity and mortality is high in patients undergoing high‐risk surgery. This study investigated whether impaired glucose regulation and elevated glycated haemoglobin (HbA_1c) levels are associated with increased cardiac ischaemic events in vascular surgery patients. Methods Baseline glucose and HbA_1c were measured in 401 vascular surgery patients. Glucose < 5.6 mmol/l was defined as normal. Fasting glucose 5.6–7.0 mmol/l or random glucose 5.6–11.1 mmol/l was defined as impaired glucose regulation. Fasting glucose ≥ 7.0 or random glucose ≥ 11.1 mmol/l was defined as diabetes. Perioperative ischaemia was identified by 72‐h Holter monitoring. Troponin T was measured on days 1, 3 and 7 and before discharge. Cardiac death or Q‐wave myocardial infarction was noted at 30‐day and longer‐term follow‐up (mean 2.5 years). Results Mean (± sd ) level for glucose was 6.3 ± 2.3 mmol/l and for HbA_1c 6.2 ± 1.3%. Ischaemia, troponin release, 30‐day and long‐term cardiac events occurred in 27, 22, 6 and 17%, respectively. Using subjects with normal glucose levels as the reference category, multivariate analysis revealed that patients with impaired glucose regulation and diabetes were at 2.2‐ and 2.6‐fold increased risk of ischaemia, 3.8‐ and 3.9‐fold for troponin release, 4.3‐ and 4.8‐fold for 30‐day cardiac events and 1.9‐ and 3.1‐fold for long‐term cardiac events. Patients with HbA_1c > 7.0% (n = 63, 16%) were at 2.8‐fold, 2.1‐fold, 5.3‐fold and 5.6‐fold increased risk for ischaemia, troponin release, 30‐day and long‐term cardiac events, respectively. Conclusions Impaired glucose regulation and elevated HbA_1c are risk factors for cardiac ischaemic events in vascular surgery patients.     

The prevalence of retinopathy in impaired glucose tolerance and recent‐onset diabetes in the Diabetes Prevention Program

Aims Retinopathy is considered the complication most closely associated with and characteristic of diabetes mellitus. Hyperglycaemia below levels diagnostic of diabetes, so called pre‐diabetes, is associated with a low prevalence of ‘diabetic’ retinopathy. However, few longitudinal studies of non‐diabetic populations have performed repeated measures of glycaemia and screened for retinopathy to determine its occurrence in the non‐diabetic population and the onset of retinopathy in new‐onset diabetic patients. We determined the prevalence of retinopathy characteristically seen in diabetes in persons with impaired glucose tolerance and in patients with new‐onset diabetes of known duration in the Diabetes Prevention Program (DPP) cohort. Methods The DPP recruited persons with elevated fasting glucose (5.3–6.9 mmol/l) and impaired glucose tolerance, and no history of diagnosed diabetes, other than gestational diabetes not persisting after pregnancy. Seven‐field, stereoscopic fundus photography was completed a mean of 3.1 years after the development of diabetes in 594 of 878 participants who had developed diabetes during the DPP, and in a random sample of 302 participants who remained non‐diabetic. Results Retinopathy consistent with diabetic retinopathy was detected in 12.6 and 7.9% of the diabetic and non‐diabetic participants, respectively (P = 0.03, comparing prevalence in the two groups). Systolic blood pressure and HbA_1c were higher at baseline in the diabetic participants who had retinopathy compared with the diabetic participants without retinopathy. Conclusions Retinopathy characteristic of diabetes is present in persons with elevated fasting glucose and impaired glucose tolerance and no known history of diabetes. The prevalence of retinopathy is significantly higher in persons who develop diabetes, even within 3 years of diagnosis.     

Abnormal glucose tolerance in young male patients with nonalcoholic fatty liver disease

Objective: The association of nonalcoholic fatty liver disease (NAFLD) with insulin resistance and metabolic syndrome has been documented for obese men and middle‐aged men. This study was designed to determine the relationship between NAFLD and the oral glucose tolerance test (OGTT) to predict preclinical diabetes in nondiabetic young male patients (<30 years old). Methods: A total of 75 male patients who had elevated liver enzymes and who were diagnosed with NAFLD were enrolled in this study. A standard 75 g OGTT was carried out on all patients. Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were defined as a fasting plasma glucose (FPG) level ≥100 mg/dl but <126 mg/dl, and a 2‐h post‐load glucose on the OGTT of ≥140 mg/dl, but <200 mg/dl respectively. Results: According to the OGTT results, 24 (32%) patients were diagnosed as having IGT and 12 (16%) patients were diagnosed as having diabetes. Among the 48 patients with normal fasting glucose, 18 (37.6%) patients showed abnormal glucose tolerance (15 had IGT and three had diabetes). The NAFLD patients with abnormal glucose tolerance showed significant differences in age, weight, body mass index, waist–hip ratio, alanine aminotransferase, total bilirubin, total cholesterol, low‐density lipoprotein cholesterol, triglyceride, insulin, FPG and homeostasis model for insulin resistance (HOMA‐IR). Multiple regression analysis showed that age, FPG and HOMA‐IR were independent predictors of abnormal glucose tolerance. Conclusions: Although the patients were young men, an OGTT should be recommended for NAFLD patients with elevated liver enzymes and IFG to predict the risk of type 2 diabetes.     

Grading effect of abnormal glucose status on arterial stiffness and a new threshold of 2‐h post‐load glucose based on a Chinese community study

Aims/Introduction

To investigate the relationship between various glucose metabolic status and arterial stiffness, and further explore the threshold of blood glucose indices for the risk of arterial stiffness.

Materials and Methods

The present cross‐sectional study included 4,851 individuals from a Chinese community. Overnight fasting blood glucose and 2‐h post‐load glucose were sampled. Arterial stiffness was measured as brachial‐ankle pulse wave velocity. The association was examined using generalized linear regression models. The threshold effect was explored using two piecewise linear regression models by the smoothing plot.

Results

After adjustment for covariates, isolated impaired fasting glucose, isolated impaired glucose tolerance, combined glucose intolerance and newly diagnosed diabetes mellitus were associated with a greater risk of arterial stiffness compared with normal glucose tolerance (B = 18.09, 95% confidence interval [CI] 0.42–35.76, P = 0.045; B = 28.51, 95% CI: 3.40–53.62, P = 0.026; B = 60.70, 95% CI: 38.37–83.04, P < 0.001; B = 95.06, 95% CI: 71.88–118.25, P < 0.001, respectively). Furthermore, there was a non‐linear relationship between 2‐h post‐load glucose and arterial stiffness. A threshold for 2‐h post‐load glucose of 6.14 mmol/L was observed for the risk of arterial stiffness.

Conclusions

Impaired fasting glucose, impaired glucose tolerance, combined glucose intolerance and newly diagnosed diabetes mellitus were related to a greater risk of arterial stiffness compared with normal glucose levels. A threshold for 2‐h post‐load glucose of 6.14 mmol/L probably exists for the risk of arterial stiffness.     

Assessment of the new criteria for diabetes mellitus according to 10-year relative survival rates

Summary The validity of the new diagnostic criteria for diabetes mellitus for Japanese subjects was assessed by the long-term prognosis of 501 patients, found in an epidemiological survey of 6,681 people in a Japanese town. Ten-year relative survival rates were examined in relation to the 50 g oral glucose tolerance test (serum glucose determined by a ferricyanide method). Subjects were classified using the new criteria. The prognosis of normal subjects (fasting glucose <140 mg/dl (7.8 mmol/l) and 2-hour glucose level <140 mg/dl) and of subjects with fasting glucose <140 mg/dl and 2-h 140–200 mg/dl (7.8–11.1 mmol/l) did not differ from that of the general population. Diabetics (fasting140 mg/dl and 2-h200 mg/dl) showed a significantly reduced survival rate, corresponding to an excess mortality. Subjects with a fasting level <140mg/dl and 2-h 200mg/dl had a relative survival rate similar to that of normal subjects. As a group, fasting levels l40 mg/dl indicated a reduced survival rate, regardless of the 2-h level, while those with a 2-h level 200 mg/dl alone failed to show a significantly reduced survival rate. Thus, the fasting glucose values appeared to be more closely related to death rate than the 2-hour glucose values.     

Psychosocial factors are independent risk factors for the development of Type 2 diabetes in Japanese workers with impaired fasting glucose and/or impaired glucose tolerance1

Aims We prospectively studied Japanese workers with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and analysed possible risk factors for diabetes, including psychosocial factors such as stress. Methods The participants were 128 male Japanese company employees (mean age, 49.3 ± 5.9 years) with IFG and/or IGT diagnosed by oral glucose tolerance test (OGTT). Participants were prospectively studied for 5 years with annual OGTTs. The Kaplan–Meier method and Cox's proportional hazard model were used to analyse the incidence of diabetes and the factors affecting glucose tolerance, including anthropometric, biochemical and social–psychological factors. Results Of 128 participants, 36 (28.1%) developed diabetes and 39 (30.5%) returned to normal glucose tolerance (NGT) during a mean follow‐up of 3.2 years. Independent risk factors for diabetes were night duty [hazard ratio (HR) = 5.48, P = 0.002], higher fasting plasma glucose (FPG) levels within 6.1–6.9 mmol/l (HR = 1.05, P = 0.031), stress (HR = 3.81, P = 0.037) and administrative position (HR = 12.70, P = 0.045), while independent factors associated with recovery were lower FPG levels (HR = 0.94, P = 0.017), being a white‐collar worker (HR = 0.34, P = 0.033), non‐smoking (HR = 0.31, P = 0.040) and lower serum alanine aminotransferase (ALT) levels (HR = 0.97, P = 0.042). Conclusions In addition to FPG levels at baseline, psychosocial factors (night duty, stress and administrative position) are risk factors for Type 2 diabetes, while being a white‐collar worker, a non‐smoker and lower serum ALT levels are factors associated with return to NGT in Japanese workers with IFG and/or IGT.     

Unrecognized glucose intolerance is not associated with depression. Screening for Impaired Glucose Tolerance study 3 (SIGT 3)

Aims To understand the metabolic and temporal links in the relationship between diabetes and depression, we determined the association between depressive symptoms and unrecognized glucose intolerance. Methods In a cross‐sectional study, 1047 subjects without known diabetes were screened for diabetes or pre‐diabetes using the oral glucose tolerance test and for depressive symptoms using the Patient Health Questionnaire (PHQ). Results Mean age was 48 years, body mass index 30 kg/m²; 63% were female, 54% black, 11% previously treated for depression and 10% currently treated; 5% had diabetes and 34% pre‐diabetes. Median PHQ score was 2 (interquartile range 0–5). Depressive symptoms did not increase with worsening glucose tolerance, after adjusting for age, sex, ethnicity, body mass index, family history, exercise, education and depression treatment. Conclusions There is no association between depressive symptoms and unrecognized glucose intolerance. However, it remains possible that diagnosed diabetes, with its attendant health concerns, management issues, and/or biological changes, may be a risk for subsequent development of depression. Thus, patients with newly diagnosed diabetes should be counselled appropriately and monitored for the development of depression.     

Can HbA1c and One-Hour Glucose Concentration in Standard OGTT Be Used for Evaluation of Glucose Homeostasis in Childhood?

Objective: To investigate whether glycosylated hemoglobin (HbA1c) and 1-hour glucose level in oral glucose tolerance test (OGTT) are useful parameters for evaluation of glucose homeostasis in childhood.Methods: The medical records of 106 obese/overweight children aged from 7 to 18 years who underwent OGTT were evaluated retrospectively. The subjects were divided into 2 groups according to their one-hour glucose concentration. Group 1 consisted of subjects whose one-hour glucose level was <155 mg/dL, and Group 2 consisted of subjects whose one-hour glucose level was ≥155mg/dL. The fasting and 2-hour glucose concentrations of the groups werecompared. The sensitivity and specificity levels were determined using the ROC curve to assess the predictive value of HbA1c for impaired glucose tolerance (IGT).Results: The mean 2-hour glucose concentration of the subjects in Group 2 was significantly higher than that of the subjects in Group 1 (137.8±35.5 mg/dL versus 113.1±21.2 mg/dL, p<0.05). If a 5.5% cut-off value for HbA1c was accepted as predictor of IGT, the sensitivity was 63% and specificity was 70%. 31% of the subjects with HbA1c levels at or above 5.5% had IGT. This rate was significantly lower in subjects who had HbA1c levels below 5.5% (p<0.05).Conclusions: Obese/overweight children and adolescents whose 1-hourglucose level is ≥155 mg/dL in the standard OGTT carry a high risk for IGT. Obese/overweight children and adolescents whose HbA1c level is at or above 5.5% may have IGT even though their fasting glucose level is normal, thus, OGTT is necessary to evaluate the glucose tolerance.Conflict of interest:None declared.     

Meaning of upper limit of normal range of post‐load 1‐h plasma glucose level defined by oral glucose tolerance test in Japanese subjects

Aims/Introduction

To identify upper limit post‐load 1‐h plasma glucose (1‐h PG) after 75‐g oral glucose test in a Japanese population.

Materials and Methods

A total of 918 subjects were enrolled. We divided the subjects into two groups: normal 2‐h post‐load plasma glucose (2‐h PG; <140 mg/dL) and impaired 2‐h PG group (≥140 mg/dL).

Results

A total of 417 subjects had normal 2‐h PG and 501 had impaired 2‐h PG. The receiver operating characteristic (ROC) curve showed that the optimal cut‐off value of 1‐h PG was 179 mg/dL (area under ROC curve = 0.89), providing that the sensitivity, specificity, and positive and negative predictive value were 85, 79, 82 and 83%, respectively. The subjects with 1‐h PG < 179 mg/dL consisted of 0.5% diabetes and 99.5% non‐diabetes, whereas those with 1‐h PG ≥ 179 mg/dL consisted of 26.9% diabetes and 73.1% non‐diabetes (P < 0.01). Furthermore, there was a significant correlation between 1‐h PG and 2‐h PG (r² = 0.57, P < 0.01).

Conclusions

These data suggested that 179 mg/dL is the upper limit of the normal range of post‐load of 1‐h PG in a Japanese population. Thus, the subjects with 1‐h PG ≥ 179 mg/dL might be at risk of developing future diabetes. Therefore, appropriate prospective study should be carried out to test this hypothesis.     

Type 2 diabetes risk in persons with dysglycemia: the Framingham Offspring Study

Aims

Detection of risk of type 2 diabetes mellitus (T2DM) among adults with dysglycemia.

Methods

We used a nested case-cohort prospective design to estimate risk of new diabetes (diabetes treatment or FPG ≥7.0 mmol/L) among 1004 Framingham Heart Study Offspring with baseline dysglycemia [fasting plasma glucose (FPG) 5.4-6.9 mmol/L and/or 2-h post glucose load level 7.8-11.0 mmol/L]. Using clinical characteristics previously shown to predict incident T2DM, we used logistic regression to estimate odds ratios (OR), p-values for predictors, and assessment of model discrimination.

Results

At the end of 7 years follow-up there were 118 incident T2DM cases. In a model that included age, sex, elevated blood pressure or blood pressure treatment, lipid-lowering treatment and elevated triglycerides, we found the following additional characteristics to be independently associated with new T2DM: parental history of diabetes (OR 2.28, p = 0.004); excess adiposity (BMI ≥ 30 kg/m² or waist circumference ≥101.6 cm) (OR 2.04, p = 0.0005), and low HDL-C [<1.0 (men) or <1.3 mmol/L (women)] (OR 2.77, p < 0.0001). The multivariable C-statistic for this model was 0.701, and with glycemic category information included, c = 0.751.

Conclusions

The key non-glycemic traits that predicted later T2DM in adults with dysglycemia were parental history of diabetes, excess adiposity and low HDL-C.     

空腹血糖水平与胰岛素抵抗的关系

目的探讨美国糖尿病协会2003年修订的空腹血糖受损(IFG)下限新切点(5·6mmol/L)划分出的中国血糖调节异常(IGR)者是否存在胰岛素抵抗。方法选取糖调节正常者(NGR)9例;以新标准划分的单纯IFG者9例;空腹及糖负荷后血糖均异常的糖调节受损者共20例,其中以新空腹血糖(FPG)切点划分的新联合糖耐量低减(IGT)者10例;以旧FPG切点划分的旧联合IGT者10例;2型糖尿病患者10例。以高胰岛素正葡萄糖钳夹技术测定受试对象的胰岛素敏感性,以静脉葡萄糖耐量试验评估其胰岛β细胞分泌功能。结果(1)新单纯IFG组、新联合IGT组和旧联合IGT组的葡萄糖输注率(GIR)[分别为(7·2±0·8、7·0±1·5、4·8±0·4)mg·kg-1·min-1]明显低于NGR组[(10·3±0·9)mg·kg-1·min-1,P值均<0·05];旧IGT组和DM组[(5·6±1·0)mg·kg-1·min-1]处于相近水平。(2)空腹胰岛素水平在所有IGR组均升高,在DM组下降。(3)新IFG组的胰岛素一、二相分泌量和NGR组相似,但随糖代谢紊乱程度加重,胰岛素一相分泌量进行性下降,而二相分泌水平先逐渐升高,后有所降低。结论(1)新空腹血糖切点划分出的中国IGR者已经出现胰岛素抵抗。(2)随糖代谢紊乱程度的加重,胰岛素分泌缺陷趋于明显。     

A report on the diagnosis of intermediate hyperglycemia in Korea: A pooled analysis of four community-based cohort studies

Many studies show poor agreement between fasting plasma glucose (FPG)-based and 2-h postchallenge glucose (2-h PG)-based criteria to assess glucose metabolism. We examined the rate of agreement between FPG- and 2-h PG-based criteria in the diagnosis of intermediate hyperglycemia in four representative cohort studies in South Korea and compared the clinical characteristics and biochemical parameters in subjects with impaired fasting glucose (IFG) according to their FPG values.

Of 6234 subjects from four population-based studies performed from 1993 to 2000, 4610 individuals with data from a 75 g oral glucose tolerance test (OGTT) and no previous history of diabetes were selected. We examined the concordance rate between the FPG and 2-h PG-based criteria. We also investigated the differences in the clinical characteristics and biochemical parameters between individuals with IFG according to their FPG values.

The fasting and 2-h PG criteria had large discordance rates in the diagnosis of diabetes and impaired glucose tolerance (IGT) in Korean adults. When individuals with IFG were classified into stage 1 [5.6–6.1 mmol/L (100–109 mg/dL)] and stage 2 [6.1–7.0 mmol/L (110–125 mg/dL)] IFG, individuals with stage 2 IFG are more obese and had higher blood pressure and total cholesterol and triglycerides concentrations compared with those with stage 1 IFG. In addition, more individuals with stage 2 IFG were with diabetes as determined by a 2-h PG ≥ 11.1 mmol/L (14.1% vs. 1.9%) (P < 0.05).

Considering the poorer metabolic profile and higher percentage of people with diabetes by OGTT, these data indicate that, in the Korean population, individuals with stage 2 IFG should be treated differently from those with stage 1 IFG. To detect more cases of diabetes, the OGTT is recommended for all individuals with stage 2 IFG and cases with stage 1 IFG with some additional risk factors for diabetes.     

Depression is not associated with peripheral insulin resistance in patients with chronic hepatitis C infection

Depression is common in individuals infected with hepatitis C virus (HCV), and both depression and HCV infection are independently associated with insulin resistance (IR). To evaluate the relationship between depression and IR, among other factors, in an HCV‐infected cohort. In this cross‐sectional analysis, seventy‐four non‐type 2 diabetic, noncirrhotic, HCV‐infected patients underwent comprehensive clinical, histologic and metabolic evaluation. IR was assessed directly with an insulin suppression test by measuring steady‐state plasma glucose (SSPG) levels during continuous infusions of octreotide, glucose and insulin. Logistic regression modelling was used to evaluate predictors associated with depression. Thirty‐nine (53%) patients were depressed, and 21 (54%) depressed patients were on at least one antidepressant. A higher estimated proportion of depressed patients were Caucasian (51% vs 20%, P = 0.005), unemployed (69% vs 49%, P = 0.07), heavier smokers (18 pack‐years vs 13 pack‐years, P = 0.07), on substance abuse therapy (16% vs 3%, P = 0.06) and had lower HDL levels (1.2 mmol/L vs 1.4 mmol/L, P = 0.01). The mean SSPG levels in depressed and nondepressed patients were 7.3 and 8.3 mmol/L (P = 0.45), respectively. In multipredictor adjusted analysis, only Caucasian race (OR 4.19, 95% CI 1.42–12.35, P = 0.009) and lower HDL (OR 0.95, 95% CI 0.89–0.99, P = 0.046) were associated with depression. In conclusion, although prevalent, depression was not associated with peripheral IR in this HCV‐infected cohort. Attention to other modifiable factors associated with depression in the HCV‐infected population is warranted.     

Relationship between glucose tolerance,insulin secretion,and insulin action in non-obese individuals with varying degrees of glucose tolerance

Summary Plasma glucose and insulin concentration following a 75 g oral glucose challenge and glucose uptake during a hyperinsulinaemic glucose clamp study were determined in 50 non-obese individuals. The study population was divided into five groups on the basis of their glucose tolerance: normal, impaired glucose tolerance, Type 2 (non-insulin-dependent) diabetes mellitus with fasting plasma glucose of less than 8 mmol/l, between 8–15 mmol/l, and more than 15 mmol/l. The plasma insulin response was significantly greater (p<0.001) than normal in those with either impaired glucose tolerance or Type 2 diabetes and a fasting plasma glucose concentration less than 8 mmol/l. In contrast, the plasma insulin response was similar to normal in the other two groups of patients with Type 2 diabetes, i.e. fasting plasma glucose concentration 8–15 mmol/l or greater than 15 mmol/l. Glucose uptake rates were significantly lower (p<0.001) than normal in subjects with impaired glucose tolerance and all three groups of patients with Type 2 diabetes. Although glucose uptake rates during the glucose clamp studies were relatively similar in all four groups of glucose intolerant subjects, the values were significantly lower in those patients with Type 2 diabetes who had a fasting plasma glucose concentration greater than 8 mmol/l (p<0.01), These data indicate that a significant degree of insulin resistance exists in patients with impaired glucose tolerance or Type 2 diabetes, relatively independent of fasting plasma glucose concentration. Indeed, glucose uptake during glucose clamp studies fell 8-fold over a range in fasting plasma glucose concentration of from 4.5 to 6.5 mmol/l. In contrast, the plasma insulin response increased over the same range of fasting plasma glucose concentrations. The fact that this defect in insulin action can be seen in patients who are hyperinsulinaemic, not hypoinsulinaemic, and only modestly hyperglycaemic, is consistent with the hypothesis that resistance to insulin-stimulate glucose uptake is a basic characteristic of patients with impaired glucose tolerance or Type 2 diabetes.     

Normal fasting plasma glucose and risk of prediabetes and type 2 diabetes: the Isfahan Diabetes Prevention Study

AIM: To determine the association of fasting plasma glucose (FPG) level within normal range and the risk of prediabetes and type 2 diabetes in an Iranian population. METHODS: A total of 806 first-degree relatives (FDRs) of patients with type 2 diabetes who had FPG levels less than 5.6 mmol/l (100 mg/dl) in 2003 to 2005, and who did not have diabetes or impaired fasting glucose (IFG), were followed through 2010 for the occurrence of prediabetes or type 2 diabetes. At baseline and through follow-ups, participants underwent a standard 75 g 2-hour oral glucose tolerance test (OGTT). RESULTS: The incidence of type 2 diabetes, impaired glucose tolerance (IGT), and IFG was 9.6 (95% confidence interval (CI): 6.8-12.4), 28.7 (23.8-33.6), and 33.0 (27.7-38.2) per 1,000 person-years based on 4,489 person-years of follow-up, respectively. FPG was associated with the incidence of diabetes, IGT, and IFG. The multivariate-adjusted hazard ratios (95% CI) for diabetes, IGT, and IFG were 1.36 (1.01-1.84), 1.45 (1.10-1.91) and 1.31 (1.00-1.71), for the highest quintile of FPG compared with the lowest quintile, respectively. CONCLUSIONS: An increase in FPG in the normal range is associated with an increase in the incidence of IGT, IFG, and type 2 diabetes. These results prove FPG in the normal range to be useful in identifying apparently healthy FDRs of patients with type 2 diabetes at risk of developing prediabetes and diabetes.     

Differences in height explain gender differences in the response to the oral glucose tolerance test— the AusDiab study

Aim To determine the extent of gender‐related differences in the prevalence of glucose intolerance for the Australian population and whether body size may explain such differences. Methods Cross‐sectional data were collected from a national cohort of 11 247 Australians aged ≥ 25 years. Glucose tolerance status was assessed according to both fasting plasma glucose (FPG) and 2‐h plasma glucose (2hPG) levels following a 75‐g oral glucose tolerance test (OGTT). Anthropometric and glycated haemoglobin measurements were also made. Results Undiagnosed diabetes and non‐diabetic glucose abnormalities were more prevalent among men than women when based only on the FPG results (diabetes: men 2.2%, women 1.6%, P = 0.02; impaired fasting glycaemia: men 12.3%, women 6.6%, P < 0.001). In contrast 16.0% of women and 13.0% of men had a 2hPG abnormality (either diabetes or impaired glucose tolerance, P = 0.14). Women had a mean FPG 0.3 mmol/l lower than men (P < 0.001), but 2hPG 0.3 mmol/l higher (P = 0.002) and FPG‐2hPG increment 0.5 mmol/l greater (P < 0.001). The gender difference in mean 2hPG and FPG‐2hPG increment disappeared following adjustment for height. For both genders, those in the shortest height quartile had 2hPG levels 0.5 mmol/l higher than the tallest quartile, but height showed almost no relationship with the FPG. Conclusions Men and women had different glycaemic profiles; women had higher mean 2hPG levels, despite lower fasting levels. It appeared that the higher 2hPG levels for women related to lesser height and may be a consequence of using a fixed glucose load in the OGTT, irrespective of body size.     

Impaired glucose tolerance in first‐episode drug‐naïve patients with schizophrenia

Aims To determine whether there is an association between Type 2 diabetes mellitus and schizophrenia, independent of medication. Methods In this cross‐sectional study we performed an oral glucose tolerance test on 38 non‐obese white Caucasians who fulfilled the criteria for first‐episode drug‐naïve schizophrenia, 38 control subjects (matched for age, gender, smoking status, alcohol intake and ethnicity) and 44 first‐degree relatives of the patients. Results The frequency of impaired glucose tolerance (IGT), defined by World Health Organization criteria, was 10.5% (n = 4) in patients with schizophrenia, 18.2% (n = 8) in unaffected relatives and 0.0% in healthy control subjects (χ² = 4.22, d.f. = 2, P < 0.05). Conclusions The high point prevalence of IGT in never‐treated patients and relatives supports either shared environmental or genetic predisposition to IGT. Both patients and their relatives present an ideal cost‐effective opportunity to screen for Type 2 diabetes mellitus, as they are both easily identifiable.     

Predictability of 1‐h postload plasma glucose concentration: A 10‐year retrospective cohort study

Aims/Introduction

Elevated 1-h postload plasma glucose concentration (1hPG) during oral glucose tolerance test has been linked to an increased risk of type 2 diabetes and a poorer cardiometabolic risk profile. The present study analyzed the predictability and cut-off point of 1hPG in predicting type 2 diabetes in normal glucose regulation (NGR) subjects, and evaluated the long-term prognosis of NGR subjects with elevated 1hPG in glucose metabolism, kidney function, metabolic states and atherosclerosis.

Materials and Methods

A total of 116 Han Chinese classified as NGR in 2002 at the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China, were investigated. Follow-up was carried out in 2012 to evaluate the progression of glucose metabolism, kidney function, metabolic syndrome and carotid atherosclerosis.

Results

The areas under receiver operating characteristic curves were higher for 1hPG than FPG or 2hPG (0.858 vs 0.806 vs 0.746). The cut-off value of 1hPG with the maximal sum of sensitivity and specificity in predicting type 2 diabetes in NGR subjects was 8.85 mmol/L. The accumulative incidence of type 2 diabetes in subjects with 1hPG ≥8.85 mmol/L was higher than those <8.85 mmol/L (46.2% vs 3.3%, P = 0.000; relative risk 13.846, 95% confidence interval 4.223–45.400). On follow up, the prevalence of metabolic syndrome and abnormal carotid intima-media thickness in the subjects with 1hPG ≥8.85 mmol/L tended to be higher compared with those <8.85 mmol/L.

Conclusions

1hPG is a good predictor of type 2 diabetes in NGR subjects, and the best cut-off point is 8.85 mmol/L. Some tendency indicates that NGR subjects with 1hPG ≥8.85 mmol/L are more prone to metabolic syndrome and carotid atherosclerosis.