Clinical profiles of post-load glucose subgroups and their association with glycaemic traits over time: An IMI-DIRECT study.

AIM: To examine the hypothesis that, based on their glucose curves during a seven-point oral glucose tolerance test, people at elevated type 2 diabetes risk can be divided into subgroups with different clinical profiles at baseline and different degrees of subsequent glycaemic deterioration. METHODS: We included 2126 participants at elevated type 2 diabetes risk from the Diabetes Research on Patient Stratification (IMI-DIRECT) study. Latent class trajectory analysis was used to identify subgroups from a seven-point oral glucose tolerance test at baseline and follow-up. Linear models quantified the associations between the subgroups with glycaemic traits at baseline and 18 months. RESULTS: At baseline, we identified four glucose curve subgroups, labelled in order of increasing peak levels as 1-4. Participants in Subgroups 2-4, were more likely to have higher insulin resistance (homeostatic model assessment) and a lower Matsuda index, than those in Subgroup 1. Overall, participants in Subgroups 3 and 4, had higher glycaemic trait values, with the exception of the Matsuda and insulinogenic indices. At 18 months, change in homeostatic model assessment of insulin resistance was higher in Subgroup 4 (ß = 0.36, 95% CI 0.13-0.58), Subgroup 3 (ß = 0.30; 95% CI 0.10-0.50) and Subgroup 2 (ß = 0.18; 95% CI 0.04-0.32), compared to Subgroup 1. The same was observed for C-peptide and insulin. Five subgroups were identified at follow-up, and the majority of participants remained in the same subgroup or progressed to higher peak subgroups after 18 months. CONCLUSIONS: Using data from a frequently sampled oral glucose tolerance test, glucose curve patterns associated with different clinical characteristics and different rates of subsequent glycaemic deterioration can be identified.

Impact of mismatches in HbA1c vs glucose values on the diagnostic classification of diabetes and prediabetes.

AIMS: To determine whether HbA1c mismatches (HbA1c levels that are higher or lower than expected for the average glucose levels in different individuals) could lead to errors if diagnostic classification is based only on HbA1c levels. METHODS: In a cross-sectional study, 3106 participants without known diabetes underwent a 75-g oral glucose tolerance test (fasting glucose and 2-h glucose) and a 50-g glucose challenge test (1-h glucose) on separate days. They were classified by oral glucose tolerance test results as having: normal glucose metabolism; prediabetes; or diabetes. Predicted HbA1c was determined from the linear regression modelling the relationship between observed HbA1c and average glucose (mean of fasting glucose and 2-h glucose from the oral glucose tolerance test, and 1-h glucose from the glucose challenge test) within oral glucose tolerance test groups. The haemoglobin glycation index was calculated as [observed - predicted HbA1c ], and divided into low, intermediate and high haemoglobin glycation index mismatch tertiles. RESULTS: Those participants with higher mismatches were more likely to be black, to be men, to be older, and to have higher BMI (all P<0.001). Using oral glucose tolerance test criteria, the distribution of normal glucose metabolism, prediabetes and diabetes was similar across mismatch tertiles; however, using HbA1c criteria, the participants with low mismatches were classified as 97% normal glucose metabolism, 3% prediabetes and 0% diabetes, i.e. mostly normal, while those with high mismatches were classified as 13% normal glucose metabolism, 77% prediabetes and 10% diabetes, i.e. mostly abnormal (P<0.001). CONCLUSIONS: Measuring only HbA1c could lead to under-diagnosis in people with low mismatches and over-diagnosis in those with high mismatches. Additional oral glucose tolerance tests and/or fasting glucose testing to complement HbA1c in diagnostic classification should be performed in most individuals.

Testosterone level in aging male with different glucose tolerance state and its association with osteocalcin.

OBJECTIVE: To investigate the relationship of testosterone and different glucose tolerance state, and its association with osteocalcin. METHODS: A cross-sectional study was conducted of 1176 males aged 60-97 years who were arranged for an annual regular checkup from March to May 2012 in Chinese PLA general hospital in Beijing. RESULTS: Individuals categorized as having prediabetes or diabetes were more likely to have lower osteocalcin, testosterone, and SHBG levels compared to those with normal glucose tolerance (p < .05 in males). In aging males, after adjusting for age, the negative association between osteocalcin and BMI, waist circumference, FPG, 2hPBG, or TG were significant. And serum TT was negatively associated with BMI, waist circumference, FPG, 2hPBG, or TG independent of age, ALP, Ca, P, VitD, and PTH. CONCLUSIONS: It showed that serum osteocalcin and TT were closely related with BMI, blood glucose, and TG, which supported the hypothesis that regulation of bone remodeling, energy metabolism, and reproduction are linked.

Plasma Metabolomics to Identify and Stratify Patients With Impaired Glucose Tolerance.

OBJECTIVE: Impaired glucose tolerance (IGT) is one of the presymptomatic states of type 2 diabetes mellitus and requires an oral glucose tolerance test (OGTT) for diagnosis. Our aims were twofold: (i) characterize signatures of small molecules predicting the OGTT response and (ii) identify metabolic subgroups of participants with IGT. METHODS: Plasma samples from 827 participants of the Study of Health in Pomerania free of diabetes were measured using mass spectrometry and proton-nuclear magnetic resonance spectroscopy. Linear regression analyses were used to screen for metabolites significantly associated with the OGTT response after 2 hours, adjusting for baseline glucose and insulin levels as well as important confounders. A signature predictive for IGT was established using regularized logistic regression. All cases with IGT (N = 159) were selected and subjected to unsupervised clustering using a k-means approach. RESULTS AND CONCLUSION: In total, 99 metabolites and 22 lipoprotein measures were significantly associated with either 2-hour glucose or 2-hour insulin levels. Those comprised variations in baseline concentrations of branched-chain amino ketoacids, acylcarnitines, lysophospholipids, or phosphatidylcholines, largely confirming previous studies. By the use of these metabolites, subjects with IGT segregated into two distinct groups. Our IGT prediction model combining both clinical and metabolomics traits achieved an area under the curve of 0.84, slightly improving the prediction based on established clinical measures. The present metabolomics approach revealed molecular signatures associated directly to the response of the OGTT and to IGT in line with previous studies. However, clustering of subjects with IGT revealed distinct metabolic signatures of otherwise similar individuals, pointing toward the possibility of metabolomics for patient stratification.

Increasing the accuracy of oral glucose tolerance testing and extending its application to individuals with normal glucose tolerance for the prediction of type 1 diabetes: the Diabetes Prevention Trial-Type 1.

OBJECTIVE: We assessed the extent to which both standard and alternative indexes from 2-h oral glucose tolerance testing predict type 1 diabetes and whether oral glucose tolerance tests (OGTTs) predict type 1 diabetes in individuals with normal glucose tolerance. RESEARCH DESIGN AND METHODS: The prediction of type 1 diabetes from baseline OGTTs was studied in 704 Diabetes Prevention Trial-Type 1 participants (islet-cell autoantibody [ICA]-positive relatives of type 1 diabetic patients). The maximum follow-up was 7.4 years. Analyses utilized receiver-operator curves (ROCs), proportional hazards models, and survival curves. RESULTS: ROC areas under the curve (ROCAUCs) for both the AUC glucose (0.73 +/- 0.02) and an OGTT prediction index (0.78 +/- 0.02) were higher (P < 0.001) than those for the fasting (0.53 +/- 0.02) and 2-h glucose (0.66 +/- 0.02). ROCAUCs for the 60- and 90-min glucose (0.71 +/- 0.02 and 0.72 +/- 0.02, respectively) were also higher (P < 0.01) than those for the fasting and 2-h glucose. Among individuals with normal glucose tolerance, OGTTs were highly predictive, with 4th versus 1st quartile hazard ratios for the 2-h glucose, AUC glucose, and OGTT prediction index ranging from 3.77 to 5.30 (P < 0.001 for all). CONCLUSIONS: Certain alternative OGTT indexes appear to better predict type 1 diabetes than standard OGTT indexes in ICA-positive relatives of type 1 diabetic patients. Moreover, even among those with normal glucose tolerance, OGTTs are strongly predictive. This suggests that subtle metabolic abnormalities are present several years before the diagnosis of type 1 diabetes.

Glycaemic variability-based classification of impaired glucose tolerance vs. type 2 diabetes using continuous glucose monitoring data.

Many glycaemic variability (GV) indices extracted from continuous glucose monitoring systems data have been proposed for the characterisation of various aspects of glucose concentration profile dynamics in both healthy and non-healthy individuals. However, the inter-index correlations have made it difficult to reach a consensus regarding the best applications or a subset of indices for clinical scenarios, such as distinguishing subjects according to diabetes progression stage. Recently, a logistic regression-based method was used to address the basic problem of differentiating between healthy subjects and those affected by impaired glucose tolerance (IGT) or type 2 diabetes (T2D) in a pool of 25 GV-based indices. Whereas healthy subjects were classified accurately, the distinction between patients with IGT and T2D remained critical. In the present work, by using a dataset of CGM time-series collected in 62 subjects, we developed a polynomial-kernel support vector machine-based approach and demonstrated the ability to distinguish between subjects affected by IGT and T2D based on a pool of 37 GV indices complemented by four basic parameters-age, sex, BMI, and waist circumference-with an accuracy of 87.1%.

Effect of pioglitazone on insulin secretion in patients with both impaired fasting glucose and impaired glucose tolerance.

AIM: To evaluate the effect of a thiazolidinedione, pioglitazone, on insulin secretion in patients with both impaired fasting glucose and impaired glucose tolerance. METHODS: A randomized, double-blind, placebo-controlled clinical trial was carried out in 18 overweight or obese patients with both impaired fasting glucose and impaired glucose tolerance. Pharmacological intervention consisted of an oral morning administration of pioglitazone (30 mg) or a placebo with a similar presentation for 30 days. Before and after the intervention, glucose, creatinine, lipid profile and uric acid concentrations were measured. To evaluate insulin secretion (early, late and total phases) and insulin sensitivity, a hyperglycemic-hyperinsulinemic clamp was also performed. RESULTS: There were significant reductions (p=0.008) in fasting insulin concentration (121 versus 45 pmol/l), late (565 versus 307 pmol/l) and total insulin secretion (474 versus 254 pmol/l), as well as, in 2h postload glucose levels (9.7 versus 6.9 mmol/l, p=0.028), with an increment in insulin sensitivity after pioglitazone administration (7.5 versus 9.9). CONCLUSION: Pioglitazone administration during a period of 4 weeks decreased late and total insulin secretion phases, fasting insulin and 2h postload glucose levels, and improved insulin sensitivity in patients with both impaired fasting glucose and impaired glucose tolerance.

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.

Implications of new diagnostic criteria for abnormal glucose homeostasis in women with previous gestational diabetes.

OBJECTIVE: To determine the consequences of applying revised American Diabetes Association (ADA) (1997) and World Health Organization (WHO) (1998) recommendations for the classification of glucose intolerance in women with previous gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: There were 192 women with previous GDM who took an oral glucose tolerance test (OGTT) 1-86 months after delivery and were classified by WHO (1985), ADA (1997, fasting glucose), and revised WHO (1998) guidelines. RESULTS: Among the 165 women without a preexisting diagnosis of diabetes, WHO-1985 and ADA-1997 provided similar estimates of diabetes prevalence (13.3% vs. 11.5%) but widely differing estimates of impaired glucose homeostasis (31.5% impaired glucose tolerance [IGT] by WHO-1985 vs. 10.9% impaired fasting glucose by ADA-1997 criteria). Overall, 56 women (34%) showed a classification discrepancy between WHO-1985 and ADA-1997 criteria, including 44 with normal fasting glucose by ADA-1997 criteria, but abnormal 2-h glucose by WHO-1985 criteria (40 IGT, 4 diabetes). The cardiovascular risk profile of these women was more favorable than that of 18 women with impaired fasting glucose. WHO-1998 recommendations reproduced ADA-1997 findings when used as a fasting screen, but behaved similarly to WHO-1985 criteria when 2-h glucose values were also analyzed. CONCLUSIONS: All criteria produced similar estimates of diabetes prevalence. However, analyses based on a single fasting glucose screen (and a threshold of 6.1 mmol/l) failed to identify 60% of women with abnormal 2-h glucose levels. Screening women with previous GDM (and by analogy, other groups at high risk of diabetes) with a single fasting glucose has low sensitivity for the detection of abnormal glucose tolerance. Recent guidelines recommending this approach require reevaluation.

Lack of agreement between the revised criteria of impaired fasting glucose and impaired glucose tolerance in children with excess body weight.

OBJECTIVE: The aim of this study was to describe the agreement between impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) in children with excess body weight using the original and the revised definitions of IFG. RESEARCH DESIGN AND METHODS: Obese and overweight children aged 4-17 years were included (n = 533). Anthropometric parameters and biochemical tests (fasting and 2-h glucose tests after an oral glucose load [1.75 g/kg]) were performed. Case subjects with a fasting plasma glucose >/=126 mg/dl were excluded. The diagnostic parameters of the original and the revised definitions of IFG for detecting IGT were estimated. The analysis of agreement between these categories was made using the kappa test. RESULTS: The prevalence of IFG increased from 6.2 to 13.3% using the new criteria. The prevalence of IFG became closer to the prevalence of IGT (14.8%). The revised criteria increased the sensitivity from 26.6 to 36.7%. However, the new IFG definition was not useful for identifying IGT cases. Of the 71 case subjects with IFG, only 29 (40.8%) had IGT. In addition, 50 case subjects with IGT (9.4%) and 13 with diabetes (2.4%) had a fasting glycemia <100 mg/dl. A poor agreement was found between the 2003 IFG definition and abnormal 2-h postchallenge plasma glucose (kappa = 0.359). The proportion of false-positive cases increased (36.3-59.1%) under the new definition. CONCLUSIONS: The new definition modestly increases the sensitivity of IFG for detecting IGT in children with excess body weight. Despite this, more than one-half of these cases are not detected. In addition, the false-positive rate was increased by 61%.

Cardiovascular risk profile in individuals with borderline glycemia: the effect of the 1997 American Diabetes Association diagnostic criteria and the 1998 World Health Organization Provisional Report.

OBJECTIVE: In 1997, the American Diabetes Association (ADA) recommended a new diagnostic category, impaired fasting glucose (IFG), to describe individuals with borderline glucose tolerance. On the other hand, the World Health Organization (WHO) suggested retaining the category of impaired glucose tolerance (IGT). We studied the prevalence of IFG and IGT in a multiethnic society and compared the cardiovascular risk profiles of subjects with IFG, IGT, or both IFG and IGT. RESEARCH DESIGN AND METHODS: A total of 3,568 subjects were examined from the 1992 National Health Survey of Singapore, which involved a combination of disproportionately stratified sampling and systematic sampling. Anthropometric, blood pressure, insulin, lipid profile, and uric acid measurements were taken, and a standard 75-g oral glucose tolerance test was performed after a 10-h overnight fast. RESULTS: The prevalence rates of IFG only, IGT only, and both IFT and IGT were 3.45, 10.2, and 3.4%, respectively. The degree of agreement (kappa) between the two diagnostic criteria (the ADA IFG and the WHO IGT) was only 0.25. A fasting glucose level of 5.5 mmol/l was the optimal cutoff for predicting a 2-h postload glucose level of > or =7.8 mmol/l. The following cardiovascular risk factors were higher in subjects with both IFG and IGT compared with those with either IFG or IGT alone: systolic blood pressure (131 +/- 20 vs. 125 +/- 21 and 125 +/- 19 mmHg, respectively; P < 0.05 and P < 0.001, respectively); diastolic blood pressure (77 +/- 12 vs. 73 +/- 12 and 74 +/- 12 mmHg, respectively; P < 0.05); BMI (26.2 +/- 4.2 vs. 24.4 +/- 4.0 and 24.6 +/- 4.4 kg/m2, respectively; P < 0.01 and P < 0.001, respectively); waist circumference (84.1 +/- 10.3 vs. 79.3 +/- 10.7 and 79.3 +/- 10.6 cm, respectively; P < 0.001); waist-to-hip ratio (0.84 +/- 0.08 vs. 0.82 +/- 0.09 and 0.81 +/- 0.08, respectively; P < 0.05 and P < 0.001, respectively); fasting insulin (12.1 +/- 9.7 vs. 9.2 +/- 5.3 and 9.9 +/- 7.7 mU/l; P < 0.01); insulin resistance (by homeostasis model assessment [HOMA]) (3.41 +/- 2.77 vs. 2.58 +/- 1.50 and 2.43 +/- 1.83, respectively; P < 0.01 and P < 0.001, respectively); total cholesterol (5.81 +/- 1.1 vs. 5.51 +/- 1.1 and 5.53 +/- 1.1 mmol/l, respectively; P < 0.05) and apolipoprotein(B) [apo(B)] (1.5 +/- 0.38 vs. 1.40 +/- 0.34 and 1.39 +/- 0.35 mmol/l, respectively; P < 0.01). The pattern of difference remained significant only for fasting insulin, insulin resistance (HOMA), and apo(B) (borderline) after adjustment for age, sex, and ethnic differences. CONCLUSIONS: Obvious discordance was evident in the classification of glycemic status when applying the criteria proposed by the ADA (IFG) or WHO (IGT) in a multiethnic society like Singapore. However, subjects with either IFG or IGT had similar cardiovascular risk profiles. Therefore, both criteria identified individuals at high risk for cardiovascular disease. Individuals with both IFG and IGT had a greater incidence of the cardiovascular dysmetabolic syndrome.

Impaired glucose tolerance is a risk factor for cardiovascular disease, but not impaired fasting glucose. The Funagata Diabetes Study.

OBJECTIVE: To determine whether the new category of impaired fasting glucose (IFG) recently proposed by the Expert Committee of the American Diabetes Association is a risk factor for cardiovascular disease. RESEARCH DESIGN AND METHODS: Death certificates and residence transfer documents from the cohort population consisting of participants of the diabetes prevalence study in Funagata, Yamagata prefecture, Japan, 1990-1992, were analyzed up through the end of 1996. First, the cohort population was classified into three groups: normal glucose tolerance (NGT) (n = 2,016), impaired glucose tolerance (IGT) (n = 382), and diabetic (n = 253). Then the same population was reclassified into normal fasting glucose (NFG), IFG, and diabetic. The cumulative survival rates among the groups were compared using the classical life-table method, and age-adjusted analyses, the person-year method, and Cox's proportional hazard model were adopted. RESULTS: At the end of seven observed years, the cumulative survival rates from cardiovascular disease of IGT and diabetes were 0.962 and 0.954, respectively, both significantly lower than that of NGT (0.988). The Cox's proportional hazard model analysis showed that the hazard ratio of IGT to NGT on death from cardiovascular disease was 2.219 (95% CI 1.076-4.577). However, the cumulative survival rate of IFG from cardiovascular disease was 0.977, not significantly lower than that of NFG (0.985). The Cox's hazard ratio of IFG to NFG on death from cardiovascular disease was 1.136 (0.345-3.734), which was not significant either. CONCLUSIONS: IGT was a risk factor for cardiovascular disease, but IFG was not.

[Prevalence of type 2 diabetes mellitus and glucose intolerance in the Setif area (Algeria)]. / Prévalence du diabète de type 2 et de l'intolérance au glucose dans la région de Sétif (Algérie).

OBJECTIVE: Diabetes mellitus stands as a major public health issue in Algeria and has an important socioeconomical impact. Our study involved a representative sample of 1457 subjects and aimed at assessing the prevalence of type 2 diabetes and glucose intolerance in the population of Setif Wilaya, aged between 30 and 64 years old. MATERIAL AND METHODS: Diagnosis was based on oral glucose tolerance test, according to World Health Organisation criteria. RESULTS: Diabetes prevalence was 8.2% (CI: 95%: 6.8% to 9.6%). It increased with age, while 50% of cases were undiagnosed, without any difference according to sex nor urban (7.3%)/rural (9.7%) distribution. Glucose intolerance prevalence was 7.1 (CI 95%: 5,8% to 8,4%). Age-standardized prevalence, according to world population data provided by WHO, was 9.08% for diabetes and 7.5% for glucose intolerance. When the new American Diabetes Association Criteria were used, prevalence of type 2 diabetes was 8.8 (CI: 95%: 7.3% to 10.2%) and that of fasting hyperglycemia was 6.9% (CI: 95%: 5.6 to 8.2). According to these new criteria, among the 66 cases with undiagnosed diabetes, 79% presented with a fasting blood glucose > or =126 mg/dl. CONCLUSION: This relatively high diabetes prevalence calls for an appropriate management and health education, particularly focused on high risk subjects. These results bring the the first detailed prevalence data in an Algerian population.

Diagnostic criteria for diabetes mellitus and other categories of glucose intolerance: 1997 criteria by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus (ADA), 1998 WHO consultation criteria, and 1985 WHO criteria. World Health Organization.

To compare 1997 ADA diagnostic criteria for diabetes mellitus and other categories of glucose intolerance/1998 WHO Consultation criteria versus 1985 WHO criteria, we analyzed data from a 75-g oral glucose tolerance test (OGTT) performed on 1051 high-risk subjects without medical history of diabetes at Diabetes Screening Clinic, Ramathibodi Hospital, Thailand. There were 372 males and 679 females, aged (mean +/- S.D.) = 50.3 +/- 12.55 years, BMI = 25.62 +/- 4.39 kg/m2. If fasting plasma glucose (FPG) was used as recently recommended then 54.1, 20.4, and 25.5% of cases were classified as normal, impaired fasting glucose (IFG), and diabetic, respectively. In diagnosing diabetes using a full OGTT based on the 1985 WHO criteria as the reference test, FPG > or = 7 mmol/l had a sensitivity of 57.7%, specificity of 97.4%, positive predictive value of 94.0%, and negative predictive value of 76.4%; 53.7% of subjects with IFG had 2-h plasma glucose > or = 11.1 mmol/l. The 1997 ADA/1998 WHO Consultation criteria and 1985 WHO criteria for a full OGTT yield similar overall results. FPG ( > or = 7 mmol/l) was not sensitive for diagnosing diabetes. Moreover, about half of the subjects with IFG were actually diabetic. Therefore, OGTT remains a valuable test in diagnosing diabetes and classifying various categories of glucose intolerance.

The new classification of diabetes mellitus and IGT: a critical approach.

In 1999 WHO published the new recommendations for diagnostic criteria for diabetes. The same publication introduced several new categories including the first proposal for diagnostic criteria for the metabolic syndrome. Also, WHO established a new category labelled "impaired fasting glycaemia", and thereafter this new group and the already established impaired glucose tolerance was combined as a common entity labelled "impaired glucose regulation".--These recommendations from WHO followed a decision in the American Diabetes Association to lower the diagnostic plasma glucose threshold for diabetes in the fasting state from 7.8 to 7.0 mmol/l and to use fasting values as the diagnostic test for diabetes. The suggested changes in the diagnostic criteria will include a new group of individuals as having diabetes, while others may be left undiagnosed if fasting glucose values are used as the only diagnostic criteria. The consequence of this has been analysed by several groups including the collaborative European activity (the DECODE-study).--This review summarises the findings. One major problem is that if fasting glucose values are used as the only diagnostic criteria in screening for diabetes, approximately one third of the diabetic individuals will be left undiagnosed. Furthermore, this group is the group of diabetic patients that have the highest mortality from cardiovascular disease and stroke, and the group with the worst cardiovascular risk profile compared to individuals with elevated fasting glucose values alone. This observation raises the need for a continued use of the oral glucose tolerance test in selected groups.

Impact of the 1997 American Diabetes Association criteria on classification of glucose intolerance among Kuwaitis below 50 years of age.

Type 2 (non-insulin-dependent) diabetes is emerging as a leading chronic non-communicable disease among the adult Kuwaiti population. Based on the World Health Organization and similar reports the projected estimates for subjects suffering from type 2 diabetes by the years 2000 and 2010 show a striking tendency to high rates of the disease in our area. We report the prevalence rates of glucose intolerance among a relatively young adult Kuwaiti population below 50 years of age and the effect of implementing the recent 1997 American Diabetes Association diagnostic criteria on the frequency of type 2 diabetes, impaired glucose tolerance and impaired fasting glucose among this group. The overall prevalence rate for the three categories of glucose intolerance reached as high as 15.8% (95% CI, 14.2 to 17.4). Age, though all subjects were below 50 years, parental history of type 2 diabetes, diastolic blood pressure and serum triglycerides were found to be significant associated risk factors for the development of type 2 diabetes. Obesity was an apparent significant factor associated with the three forms of glucose intolerance (p < 0.001). Obesity and physical inactivity were documented in both non-diabetic and more so in diabetic Kuwaiti adults, which should form the basis of any immediate intervention programme. An integrated approach to the prevention of the described critical risk factors associated with type 2 diabetes is highly recommended in Kuwait. Research, focused on genetics of type 2 diabetes in the highly susceptible Kuwaiti population, should be planned.

[Plasma insulin changes in obesity with or without abnormal glucose tolerance]. / Variaciones plasmáticas de insulina en la obesidad con y sin tolerancia anormal a la glucosa.

The aim of this study was to know about the plasmatic variations of insulin and its potential origin in the obesity with or without abnormal tolerance to glucose. Obese patients with normal tolerance to glucose showed normal and hypersecretion of insulin during fasting and after oral overdose of glucose (OOG). Fasting hyperinsulinism in patients with normal secretion of insulin was due to a decrease in its hepatic clearance, whereas in patients with hypersecretion, it was due mainly to insulin hypersecretion. Most of the obese patients with glucose intolerance showed hypersecretion of insulin during fasting and after OOG, being their basal hyperinsulinism due to insulinic secretion. After the OOG, the hyperinsulinism due to insulin hypersecretion and/or a decrease in its hepatic clearance. In addition, we observed an inverse correlation between body mass index and obese patients with normal tolerance to glucose.

[Impaired glucose tolerance--current concept and its classification].

In this paper, I pointed out a few basic problems related to oral glucose tolerance test (OGTT), and reviewed historical perspective focusing on the changes of diagnostic criteria of glucose intolerance and the application of OGTT to the diagnosis of diabetes mellitus. I also commented on the historical values of the NIH proposal on "the diagnosis of diabetes mellitus and other categories of glucose tolerance" (1979), and the recommendation of both WHO Expert Committee on Diabetes Mellitus (1980) and Japan Diabetes Society Committee on Diagnosis of Diabetes Mellitus (1982). Furthermore, I discussed perspectively the problems remained to be solved in the future.

Each degree of glucose intolerance in pregnancy predicts distinct trajectories of ß-cell function, insulin sensitivity, and glycemia in the first 3 years postpartum.

OBJECTIVE: Glucose intolerance in pregnancy predicts an increased risk of future type 2 diabetes mellitus (T2DM) that is proportional to the severity of antepartum dysglycemia (i.e., highest in women with gestational diabetes mellitus [GDM], followed by those with milder dysglycemia). However, the pathophysiologic changes driving this risk are not known. Thus, we evaluated the longitudinal changes in ß-cell function, insulin sensitivity, and glycemia in the first 3 years postpartum after gestational dysglycemia. RESEARCH DESIGN AND METHODS: A total of 337 women underwent glucose challenge test (GCT) and oral glucose tolerance test (OGTT) in pregnancy, followed by repeat OGTT at 3 months, 1 year, and 3 years postpartum. The antepartum GCT/OGTT identified four gestational glucose tolerance groups: GDM (n = 105); gestational impaired glucose tolerance (GIGT; n = 60); abnormal GCT, followed by normal glucose tolerance (NGT) on the OGTT (abnormal GCT NGT; n = 96); and normal GCT with NGT (n = 76). RESULTS: At each of 3 months, 1 year, and 3 years postpartum, the prevalence of glucose intolerance increased from normal GCT NGT to abnormal GCT NGT to GIGT to GDM (all P < 0.001), whereas ß-cell function, assessed by the Insulin Secretion-Sensitivity Index-2 (ISSI-2), and insulin sensitivity (Matsuda index), progressively decreased across the groups (all P < 0.002). Each group predicted distinct trajectories of ISSI-2, Matsuda index, and fasting and 2-h glucose (all P < 0.001). Notably, GDM, GIGT, and abnormal GCT NGT predicted varying rates of declining ß-cell function and insulin sensitivity, as well as rising glycemia, compared with normal GCT NGT. CONCLUSIONS: Each degree of gestational glucose intolerance predicts distinct trajectories of ß-cell function, insulin sensitivity, and glycemia in the first 3 years postpartum that drive their differential risk of future T2DM.