Evaluation of insulin release and insulin sensitivity through oral glucose tolerance test: differences between NGT, IFG, IGT, and type 2 diabetes mellitus. A cross-sectional and follow-up study

Animal vs Plant-Based Meat: A Hearty Debate

Plant-based meat alternatives (PBMAs) are highly processed food products that typically replace meat in the diet. In Canada, the growing demand for PBMAs coincides with public health recommendations to reduce ultra-processed food consumption, which prompts the need to investigate the long-term health implications of PBMAs. This review assesses the available literature on PBMAs and cardiovascular disease (CVD), including an evaluation of their nutritional profile and impact on CVD risk factors. Overall, the nutritional profiles of PBMAs vary considerably but generally align with recommendations for improving cardiovascular health; compared with meat, PBMAs are usually lower in saturated fat and higher in polyunsaturated fat and dietary fibre. Some dietary trials that have replaced meat with PBMAs have reported improvements in CVD risk factors, including total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B-100, and body weight. No currently available evidence suggests that the concerning aspects of PMBAs (eg, food processing and high sodium content) negate the potential cardiovascular benefits. We conclude that replacing meat with PBMAs may be cardioprotective; however, long-term randomised controlled trials and prospective cohort studies that evaluate CVD events (eg, myocardial infarction, stroke) are essential to draw more definitive conclusions.

Hypertensive Disorders of Pregnancy and Long-Term Maternal Cardiovascular and Metabolic Biomarkers

OBJECTIVE

This study aimed to measure the association between hypertensive disorders of pregnancy (HDP) and long-term maternal metabolic and cardiovascular biomarkers.

STUDY DESIGN

Follow-up study of patients who completed glucose tolerance testing 5 to 10 years after enrollment in a mild gestational diabetes mellitus (GDM) treatment trial or concurrent non-GDM cohort. Maternal serum insulin concentrations and cardiovascular markers VCAM-1, VEGF, CD40L, GDF-15, and ST-2 were measured, and insulinogenic index (IGI, pancreatic β-cell function) and 1/ homeostatic model assessment (insulin resistance) were calculated. Biomarkers were compared by presence of HDP (gestational hypertension or preeclampsia) during pregnancy. Multivariable linear regression estimated the association of HDP with biomarkers, adjusting for GDM, baseline body mass index (BMI), and years since pregnancy.

RESULTS

Of 642 patients, 66 (10%) had HDP: 42 with gestational hypertension and 24 with preeclampsia. Patients with HDP had higher baseline and follow-up BMI, higher baseline blood pressure, and more chronic hypertension at follow-up. HDP was not associated with metabolic or cardiovascular biomarkers at follow-up. However, when HDP type was evaluated, patients with preeclampsia had lower GDF-15 levels (oxidative stress/cardiac ischemia), compared with patients without HDP (adjusted mean difference: -0.24, 95% confidence interval: -0.44, -0.03). There were no differences between gestational hypertension and no HDP.

CONCLUSION

In this cohort, metabolic and cardiovascular biomarkers 5 to 10 years after pregnancies did not differ by HDP. Patients with preeclampsia may have less oxidative stress/cardiac ischemia postpartum; however, this may have been observed due to chance alone given multiple comparisons. Longitudinal studies are needed to define the impact of HDP during pregnancy and interventions postpartum.

KEY POINTS

· Hypertensive disorders of pregnancy were not associated with metabolic dysfunction.. · Cardiovascular dysfunction was not consistently seen after pregnancy hypertension.. · Longitudinal studies with postpartum interventions after preeclampsia are needed..

Long-Term Maternal Metabolic and Cardiovascular Phenotypes after a Pregnancy Complicated by Mild Gestational Diabetes Mellitus or Obesity

OBJECTIVE

The aim of this study was to evaluate the association of mild gestational diabetes mellitus (GDM) and obesity with metabolic and cardiovascular markers 5 to 10 years after pregnancy.

STUDY DESIGN

This was a secondary analysis of 5- to 10-year follow-up study of a mild GDM treatment trial and concurrent observational cohort of participants ineligible for the trial with abnormal 1-hour glucose challenge test only. Participants with 2-hour glucose tolerance test at follow-up were included. The primary exposures were mild GDM and obesity. The outcomes were insulinogenic index (IGI), 1/homeostatic model assessment of insulin resistance (HOMA-IR), and cardiovascular markers vascular endothelial growth factor, (VEGF), vascular cell adhesion molecule 1 (VCAM-1), cluster of differentiation 40 ligand (CD40L), growth differentiation factor 15 (GDF-15), and suppression of tumorgenesis 2 (ST-2). Multivariable linear regression estimated the association of GDM and obesity with biomarkers.

RESULTS

Of 951 participants in the parent study, 642 (68%) were included. Lower 1/HOMA-IR were observed in treated and untreated GDM groups, compared with non-GDM (mean differences, -0.24 and -0.15; 95% confidence intervals [CIs], -0.36 to -0.12 and -0.28 to -0.03, respectively). Lower VCAM-1 (angiogenesis) was observed in treated GDM group (mean difference, -0.11; 95% CI, -0.19 to -0.03). GDM was not associated with IGI or other biomarkers. Obesity was associated with lower 1/HOMA-IR (mean difference, -0.42; 95% CI, -0.52 to -0.32), but not other biomarkers.

CONCLUSION

Prior GDM and obesity are associated with more insulin resistance but not insulin secretion or consistent cardiovascular dysfunction 5 to 10 years after delivery.

KEY POINTS

· Mild GDM increases the risk of insulin resistance 5 to 10 years postpartum but not pancreatic dysfunction.. · Obesity increases the risk of insulin resistance 5 to 10 years postpartum but not pancreatic dysfunction.. · Neither mild GDM nor obesity increased the risk of cardiovascular dysfunction 5 to 10 years postpartum..

Pregnancy Serum DLK1 Concentrations Are Associated With Indices of Insulin Resistance and Secretion

CONTEXT

Delta like noncanonical notch ligand 1 (DLK1) is a paternally expressed imprinted gene that encodes an epidermal growth factor repeat-containing transmembrane protein. A bioactive, truncated DLK1 protein is present in the circulation and has roles in development and metabolism.

OBJECTIVE

We sought to investigate links between maternal pregnancy circulating DLK1 concentrations and: (1) maternal and fetal DLK1 genotypes, (2) maternal insulin resistance and secretion, and (3) offspring size at birth.

PATIENTS, DESIGN, AND SETTING

We measured third-trimester maternal serum DLK1 concentrations and examined their associations with parentally transmitted fetal and maternal DLK1 genotypes, indices of maternal insulin resistance and secretion derived from 75-g oral glucose tolerance tests performed around week 28 of pregnancy, and offspring size at birth in 613 pregnancies from the Cambridge Baby Growth Study.

RESULTS

Maternal DLK1 concentrations were associated with the paternally transmitted fetal DLK1 rs12147008 allele (P = 7.8 × 10-3) but not with maternal rs12147008 genotype (P = 0.4). Maternal DLK1 concentrations were positively associated with maternal prepregnancy body mass index (P = 3.5 × 10-6), and (after adjustment for maternal body mass index) with both maternal fasting insulin resistance (Homeostatic Model Assessment of Insulin Resistance: P = 0.01) and measures of maternal insulin secretion in response to oral glucose (insulinogenic index: P = 1.2 × 10-3; insulin disposition index: P = 0.049). Further positive associations were found with offspring weight (P = 0.02) and head circumference at birth (P = 0.04).

CONCLUSION

These results are consistent with a partial paternal or placental origin for the maternal circulating DLK1 which may lead to increased maternal circulating DLK1 concentrations, stimulation of maternal insulin resistance and compensatory hyperinsulinemia during pregnancy, and the promotion of fetal growth.

Altered Metabolome of Lipids and Amino Acids Species: A Source of Early Signature Biomarkers of T2DM

Diabetes mellitus, a disease of modern civilization, is considered the major mainstay of mortalities around the globe. A great number of biochemical changes have been proposed to occur at metabolic levels between perturbed glucose, amino acid, and lipid metabolism to finally diagnoe diabetes mellitus. This window period, which varies from person to person, provides us with a unique opportunity for early detection, delaying, deferral and even prevention of diabetes. The early detection of hyperglycemia and dyslipidemia is based upon the detection and identification of biomarkers originating from perturbed glucose, amino acid, and lipid metabolism. The emerging “OMICS” technologies, such as metabolomics coupled with statistical and bioinformatics tools, proved to be quite useful to study changes in physiological and biochemical processes at the metabolic level prior to an eventual diagnosis of DM. Approximately 300–400 such metabolites have been reported in the literature and are considered as predicting or risk factor-reporting metabolic biomarkers for this metabolic disorder. Most of these metabolites belong to major classes of lipids, amino acids and glucose. Therefore, this review represents a snapshot of these perturbed plasma/serum/urinary metabolic biomarkers showing a significant correlation with the future onset of diabetes and providing a foundation for novel early diagnosis and monitoring the progress of metabolic syndrome at early symptomatic stages. As most metabolites also find their origin from gut microflora, metabolism and composition of gut microflora also vary between healthy and diabetic persons, so we also summarize the early changes in the gut microbiome which can be used for the early diagnosis of diabetes.

MicroRNA, Proteins, and Metabolites as Novel Biomarkers for Prediabetes, Diabetes, and Related Complications

Type 2 diabetes mellitus (T2DM) is no more a lifestyle disease of developed countries. It has emerged as a major health problem worldwide including developing countries. However, how diabetes could be detected at an early stage (prediabetes) to prevent the progression of disease is still unclear. Currently used biomarkers like glycated hemoglobin and assessment of blood glucose level have their own limitations. These classical markers can be detected when the disease is already established. Prognosis of disease at early stages and prediction of population at a higher risk require identification of specific markers that are sensitive enough to be detected at early stages of disease. Biomarkers which could predict the risk of disease in people will be useful for developing preventive/proactive therapies to those individuals who are at a higher risk of developing the disease. Recent studies suggested that the expression of biomolecules including microRNAs, proteins, and metabolites specifically change during the progression of T2DM and related complications, suggestive of disease pathology. Owing to their omnipresence in body fluids and their association with onset, progression, and pathogenesis of T2DM, these biomolecules can be potential biomarker for prognosis, diagnosis, and management of disease. In this article, we summarize biomolecules that could be potential biomarkers and their signature changes associated with T2DM and related complications during disease pathogenesis.

Changes in glucose metabolism in people with different glucose metabolism disorders at baseline: follow-up results of a Finnish national diabetes prevention programme

AIM

To examine changes in glucose metabolism (fasting and 2-h glucose) during follow-up in people with impaired fasting glucose in comparison with changes in people with isolated impaired glucose tolerance, people with impaired fasting glucose and impaired glucose tolerance combined and people with screening-detected Type 2 diabetes at baseline, among those who participated in a diabetes prevention programme conducted in Finland.

METHODS

A total of 10 149 people at high risk of Type 2 diabetes took part in baseline examination. Of 5351 individuals with follow-up ≥ 9 months, 1727 had impaired glucose metabolism at baseline and completed at least one lifestyle intervention visit. Most of them (94.6%) were overweight/ obese.

RESULTS

Fasting glucose decreased during follow-up among overweight/obese people in the combined impaired fasting glucose and impaired glucose tolerance group (P = 0.044), as did 2-h glucose in people in the isolated impaired glucose tolerance group (P = 0.0014) after adjustment for age, sex, medication and weight at baseline, follow-up time and changes in weight, physical activity and diet. When comparing changes in glucose metabolism among people with different degrees of glucose metabolism impairment, fasting glucose concentration was found to have increased in those with isolated impaired glucose tolerance (0.12 mmol/l, 95% Cl 0.05 to 0.19) and it decreased to a greater extent in those with screening-detected Type 2 diabetes (-0.54 mmol/l, 95% Cl -0.69 to -0.39) compared with those with impaired fasting glucose (-0.21 mmol/l, 95% Cl -0.27 to -0.15). Furthermore, 2-h glucose concentration decreased in the isolated impaired glucose tolerance group (-0.82 mmol/l, 95% Cl -1.04 to -0.60), in the combined impaired fasting glucose and impaired glucose tolerance group (-0.82 mmol/l, 95% Cl -1.07 to -0.58) and in the screening-detected Type 2 diabetes group (-1.52, 95% Cl -1.96 to -1.08) compared with those in the impaired fasting glucose group (0.26 mmol/l, 95% Cl 0.10 to 0.43). Results were statistically significant even after adjustment for covariates (P < 0.001 in all models).

CONCLUSIONS

Changes in glucose metabolism differ in people with impaired fasting glucose from those in people with isolated impaired glucose tolerance, people with impaired fasting glucose and impaired glucose tolerance combined and people with screening-detected Type 2 diabetes.

Prevalence of diabetes and impaired fasting glucose in Poland--the NATPOL 2011 Study

AIMS

The aim of the analysis was to assess the prevalence of diabetes and impaired fasting glucose in Poland.

METHODS

A questionnaire survey on a representative sample of 2411 Polish adults, complemented by blood pressure, anthropometric and fasting plasma glucose measurements. The research was part of the national cross-sectional NATPOL 2011 Study. Diabetes was assessed as self-reported (diagnosed) or screened (fasting plasma glucose level ≥ 7 mmol/l, based on one blood draw).

RESULTS

Total prevalence of diabetes in 2011 was 6.7% (95% CI 5.6-7.9); 6.4% (95% CI 5.0-8.0) in women and 7.0% (95% CI 5.4-8.8) in men and did not change from 2002 (6.8%, 95% CI 95% CI 5.8-7.9). Over one quarter of individuals with diabetes were not aware of having the condition. Obesity, arterial hypertension and male gender were strong predictors of screened diabetes. Total prevalence of impaired fasting glucose in the surveyed population was 15.6% (95% CI 14.0-17.2).

CONCLUSIONS

The prevalence of diabetes in Poland is similar to that observed in other European populations and has not changed over the last decade. The fact that every fourth person with diabetes is unaware of the disease creates important opportunities for screening and detection of the disease.

Novel biomarkers for pre-diabetes identified by metabolomics

A targeted metabolomics approach was used to identify candidate biomarkers of pre-diabetes. The relevance of the identified metabolites is further corroborated with a protein-metabolite interaction network and gene expression data.

Three metabolites (glycine, lysophosphatidylcholine (LPC) (18:2) and acetylcarnitine C2) were found with significantly altered levels in pre-diabetic individuals compared with normal controls.

Lower levels of glycine and LPC (18:2) were found to predict risks for pre-diabetes and type 2 diabetes (T2D).

Seven T2D-related genes (PPARG, TCF7L2, HNF1A, GCK, IGF1, IRS1 and IDE) are functionally associated with the three identified metabolites.

The unique combination of methodologies, including prospective population-based and nested case–control, as well as cross-sectional studies, was essential for the identification of the reported biomarkers.

Type 2 diabetes (T2D) can be prevented in pre-diabetic individuals with impaired glucose tolerance (IGT). Here, we have used a metabolomics approach to identify candidate biomarkers of pre-diabetes. We quantified 140 metabolites for 4297 fasting serum samples in the population-based Cooperative Health Research in the Region of Augsburg (KORA) cohort. Our study revealed significant metabolic variation in pre-diabetic individuals that are distinct from known diabetes risk indicators, such as glycosylated hemoglobin levels, fasting glucose and insulin. We identified three metabolites (glycine, lysophosphatidylcholine (LPC) (18:2) and acetylcarnitine) that had significantly altered levels in IGT individuals as compared to those with normal glucose tolerance, with P-values ranging from 2.4 × 10⁻⁴ to 2.1 × 10⁻¹³. Lower levels of glycine and LPC were found to be predictors not only for IGT but also for T2D, and were independently confirmed in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort. Using metabolite–protein network analysis, we identified seven T2D-related genes that are associated with these three IGT-specific metabolites by multiple interactions with four enzymes. The expression levels of these enzymes correlate with changes in the metabolite concentrations linked to diabetes. Our results may help developing novel strategies to prevent T2D.

The disposition index: from individual to population approach

To correctly evaluate the glucose control system, it is crucial to account for both insulin sensitivity and secretion. The disposition index (DI) is the most widely accepted method to do so. The original paradigm (hyperbolic law) consists of the multiplicative product of indices related to insulin sensitivity and secretion, but more recently, an alternative formula has been proposed with the exponent α (power function law). Traditionally, curve-fitting approaches have been used to evaluate the DI in a population: the algorithmic implementations often introduce some critical issues, such as the assumption that one of the two indices is error free or the effects of the log transformation on the measurement errors. In this work, we review the commonly used approaches and show that they provide biased estimates. Then we propose a novel nonlinear total least square (NLTLS) approach, which does not need to use the approximations built in the previously proposed alternatives, and show its superiority. All of the traditional fit procedures, including NLTLS, account only for uncertainty affecting insulin sensitivity and secretion indices when they are estimated from noisy data. Thus, they fail when part of the observed variability is due to inherent differences in DI values between individuals. To handle this inevitable source of variability, we propose a nonlinear mixed-effects approach that describes the DI using population hyperparameters such as the population typical values and covariance matrix. On simulated data, this novel technique is much more reliable than the curve-fitting approaches, and it proves robust even when no or small population variability is present in the DI values. Applying this new approach to the analysis of real IVGTT data suggests a value of α significantly smaller than 1, supporting the importance of testing the power function law as an alternative to the simpler hyperbolic law.

Association of the CD36 gene with impaired glucose tolerance, impaired fasting glucose, type-2 diabetes, and lipid metabolism in essential hypertensive patients

Essential hypertension is a common disorder that can increase the risk of type 2 diabetes (T2D). CD36 has been studied in patients with diabetes and hypertension extensively; however, few studies have focused on the relationship of the CD36 gene with impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) or T2D in essential hypertension patients. To identify rs1049673 and rs1527483 in the CD36 gene conferring susceptibility to IFG/IGT and T2D, we conducted a case-control study in 1257 essential hypertension patients among the Han Chinese population (control: 676; IGT/IFG: 468; T2D: 113). We also evaluated the impact of two loci on insulin sensitivity, glucose tolerance and serum lipid. The major findings of this study were that rs1049673 was found associated with IFG/IGT and T2D in essential hypertension patients (Pco = 0.028; Pdom = 0.015). The rs1049673 G carriers showed significant higher Glu0 (βdom = 0.08 (0.01~0.16), Pdom = 0.045) and Lp(a) (βco = 0.04 (0.002~0.07), Pco = 0.041; βdom = 0.06 (0.01~0.12), Pdom = 0.032), and lower HDL by the linear regression with the adjustment for gender, age, BMI, and mean blood pressures. These findings provided evidence that the CD36 gene may play some role in the pathogenesis of IFG/IGT and T2D in essential hypertension patients.

Determinants of glycemic control in youth with type 2 diabetes at randomization in the TODAY study

OBJECTIVE

To investigate insulin sensitivity and secretion indices and determinants of glycemic control in youth with recent-onset type 2 diabetes (T2DM) at randomization in the TODAY study, the largest study of youth with T2DM to date.

METHODS

We examined estimates of insulin sensitivity [1/fasting insulin (1/I(F)), fasting glucose/insulin (G(F) /I(F)), 1/fasting C-peptide (1/C(F)), G(F) /C(F)], β-cell function [insulinogenic index (ΔI30/ΔG30), and ΔC30/ΔG30], and disposition index (DI) in the TODAY cohort of 704 youth (14.0 ± 2.0 yr; diabetes duration 7.8 ± 5.8 months; 64.9% female; 41.1% Hispanic, 31.5% Black, 19.6% White, 6.1% American Indian, and 1.7% Asian) according to hemoglobin A1c (HbA1c) quartiles at study randomization. The randomization visit followed a run-in period (median 71 d) during which glycemic control (HbA1c ≤ 8% for at least 2 months) was achieved with metformin alone. These measures were also examined in relation to screening HbA1c levels before run-in.

RESULTS

Insulin secretion indices declined with increasing HbA1c quartiles, at randomization (ΔC30/ΔG30: 0.11 ± 0.09, 0.10 ± 0.19, 0.07 ± 0.06, and 0.03 ± 0.03 ng/mL per mg/dL, p < 0.0001; DI: 0.03 ± 0.03, 0.03 ± 0.05, 0.02 ± 0.02, and 0.01 ± 0.01 mg/dL(-1) , p < 0.0001) and at screening, with no significant difference in insulin sensitivity. There were no significant differences in estimates of insulin sensitivity or secretion between genders or across the different racial groups. At randomization and screening, HbA1c correlated with DI (r = -0.3, p < 0.001), with ΔC30/ΔG30, but not with insulin sensitivity estimates.

CONCLUSIONS

In youth with recent-onset T2DM treated with metformin, glycemic control, as measured by HbA1c, appears to be associated with residual β-cell function and not insulin sensitivity.

Association of CAPN10 gene with insulin sensitivity, glucose tolerance and renal function in essential hypertensive patients

BACKGROUND

Essential hypertension (EH) is a common disorder, which can increase the risk for type 2 diabetes (T2D). Calpain-10 (CAPN10) gene was the first candidate gene of T2D identified through genome-wide linkage and positional cloning, but few works have focused on the relationship of CAPN10 with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) in EH patients.

METHODS

To identify the effect of UCSNP-43 and UCSNP-44 in CAPN10 gene on susceptibility to IFG/IGT, we conducted a case-control study in 961 EH patients with and without IFG/IGT among Han Chinese population. We also evaluated the impact of two SNPs on insulin sensitivity and glucose tolerance estimated through oral glucose tolerance test and renal functions by blood chemical assays.

RESULTS

The major findings of this study were that UCSNP-43 displayed higher G120 and AUCg. In addition, UCSNP-44 was found associated with IFG/IGT in EH patients, and associated with increased G30, G60, AUCg, Cederholm index, Scr and eGFR. The haplotype UCSNP-43-44 was detected associated with IFG/IGT susceptibility, G60, G120, I0, AUCg, Scr and eGFR by the linear regression with the adjustment for sex, age, BMI, mean blood pressures and ACEI/ARB treatment.

CONCLUSIONS

These findings provided some evidence that CAPN10 gene may play an important role in the pathogenesis of IFG/IGT in EH patients.

Change in plasma acylation stimulating protein during euglycaemic-hyperinsulinaemic clamp in overweight and obese postmenopausal women: a MONET study

OBJECTIVE

Acylation-stimulating protein (ASP) has been shown to positively stimulate fatty acid esterification and glucose uptake in adipocytes. In vitro studies demonstrate that insulin stimulates ASP secretion from adipocytes. Individuals with obesity and/or metabolic disturbances (insulin resistance and type 2 diabetes) have increased plasma ASP.

DESIGN

The present study was designed to evaluate whether ASP levels are influenced by the metabolic profiles of overweight and obese postmenopausal women during a euglycaemic/hyperinsulinaemic clamp (EHC). Patients The study population consisted of 76 overweight and obese sedentary postmenopausal women.

MEASUREMENTS

We evaluated insulin sensitivity, plasma ASP levels, body composition including visceral adipose tissue area, blood lipid profiles, liver enzymes, peak aerobic capacity, resting metabolic rate (RMR) and total energy expenditure (TEE).

RESULTS

We observed wide interindividual variations of ASP levels during the EHC. Therefore, subjects were divided into three groups based on ASP changes. Negative ASP Responders (NAR; n = 24) showed a -20% or greater decrease in ASP levels while Positive ASP Responders (PAR; n = 42) displayed ASP fluctuations superior to +20%. Ten subjects had little or no ASP change and were considered as Zero ASP responders (ZAR). PAR women displayed a worse metabolic profile than NAR women, including higher BMI, visceral adipose tissue, fasting insulin levels, lean body mass, and alanine aminotransferase (ALT), a marker of impaired liver function. After adjustment for BMI, only ALT remained significantly different, while lean body mass (P = 0.08) and visceral adipose tissue (P = 0.07) remained marginally higher. Correlation analysis of all subjects demonstrated that fasting ASP levels correlated positively with albumin and VO(2 peak) and this association remained significant after adjustments for the effect of BMI. In addition, the percentage maximal change in ASP levels during the EHC was positively associated with BMI, lean body mass, visceral adipose tissue, fasting insulin, HOMA, TEE, RMR, ALT and AST.

CONCLUSION

Overall these results suggest that an elevated ASP response during the EHC is associated with metabolic disturbances in overweight and obese postmenopausal women.

Prevalence of impaired glucose regulation in the population of Tianjin

OBJECTIVE

To investigate the prevalence of impaired glucose regulation (IGR) in the population of Tianjin.

METHODS

A cross-sectional study was conducted in Tianjin from June to September in 2005. The multi-phasic stratified cluster sampling method was adopted. Totally, 21,454 people were selected as survey sample. Information on risk factors was collected through face-to-face questionnaire interview. Fasting capillary whole blood glucose level and other clinical indexes were tested.

RESULTS

The prevalence of impaired fasting glucose (IFG) in the population was 5.61% (5.32% in male, 5.89% in female). The prevalence of impaired glucose tolerance (IGT) was 2.91% (2.59% in male, 3.20% in female) in whole population, and the prevalence of female was significantly higher than that of male (P = 0.04). The prevalences of IFG and IGT increased with the increasing of age. And the prevalences were also influenced by the profession, educational level, and income level.

CONCLUSION

The prevalences of IGT and IFG in Tianjin are similar to those in the other big cities of China.

Factors responsible for elevation of 1-h postchallenge plasma glucose levels in Japanese men

The 1-h postchallenge plasma glucose (1-h PG) level is considered to be a good index of the development of glucose intolerance and type 2 diabetes as well as of diabetic complications. In some cases, in Japanese, 1-h PG is elevated despite normal fasting glucose during oral glucose tolerance test (OGTT), but the factors responsible remain unclear. In the present study, subjects with normal glucose tolerance (NGT), isolated impaired fasting glucose (IFG), and isolated impaired glucose tolerance (IGT) were divided into subgroups at 1-h PG of 10.0mM, and the four indices of insulin secretion and insulin sensitivity were compared. In all three categories, the insulinogenic index in subjects with elevated 1-h PG was remarkably lower than in those without elevated 1-h PG. In addition, the insulinogenic index was the strongest factor in elevated 1-h PG according to the multiple regression analysis. Interestingly, one third of the NGT subjects enrolled in this study had elevated 1-h PG. These subjects showed significantly elevated area under the curve of glucose (G-AUC) compared to NGT subjects without 1-h PG elevation. Thus, elevated 1-h PG in Japanese subjects indicates mildly impaired glucose tolerance due to decreased early-phase insulin secretion.

Hyperbolic relationship between insulin secretion and sensitivity on oral glucose tolerance test

The utility of the disposition index as a measure of beta-cell compensatory capacity rests on the established hyperbolic relationship between its component insulin secretion and sensitivity measures as derived from the intravenous glucose tolerance test (IVGTT). If one is to derive an analogous measure of beta-cell compensation from the oral glucose tolerance test (OGTT), it is thus necessary to first establish the existence of this hyperbolic relationship between OGTT-based measures of insulin secretion and insulin sensitivity. In this context, we tested five OGTT-based measures of secretion (insulinogenic index, Stumvoll first phase, Stumvoll second phase, ratio of total area-under-the-insulin-curve to area-under-the-glucose-curve (AUC(ins/gluc)), and incremental AUC(ins/gluc)) with two measures of sensitivity (Matsuda index and 1/Homeostasis Model of Assessment for insulin resistance (HOMA-IR)). Using a model of log(secretion measure) = constant + beta x log(sensitivity measure), a hyperbolic relationship can be established if beta is approximately equal to -1, with 95% confidence interval (CI) excluding 0. In 277 women with normal glucose tolerance (NGT), the pairing of total AUC(ins/gluc) and Matsuda index was the only combination that satisfied these criteria (beta = -0.99, 95% CI (-1.66, -0.33)). This pairing also satisfied hyperbolic criteria in 53 women with impaired glucose tolerance (IGT) (beta = -1.02, (-1.72, -0.32)). In a separate data set, this pairing yielded distinct hyperbolae for NGT (n = 245) (beta = -0.99, (-1.67, -0.32)), IGT (n = 116) (beta = -1.18, (-1.84, -0.53)), and diabetes (n = 43) (beta = -1.37, (-2.46, -0.29)). Moreover, the product of AUC(ins/gluc) and Matsuda index progressively decreased from NGT (212) to IGT (193) to diabetes (104) (P < 0.001), consistent with declining beta-cell function. In summary, a hyperbolic relationship can be demonstrated between OGTT-derived AUC(ins/gluc) and Matsuda index across a range of glucose tolerance. Based on these findings, the product of these two indices emerges as a potential OGTT-based measure of beta-cell function.

Glucose metabolism disorder in obese children assessed by continuous glucose monitoring system

BACKGROUND

Continuous glucose monitoring system (CGMS) can measure glucose levels at 5-minute intervals over a few days, and may be used to detect hypoglycemia, guide insulin therapy, and control glucose levels. This study was undertaken to assess the glucose metabolism disorder by CGMS in obese children.

METHODS

Eighty-four obese children were studied. Interstitial fluid (ISF) glucose levels were measured by CGMS for 24 hours covering the time for oral glucose tolerance test (OGTT). Impaired glucose tolerance (IGT), impaired fasting glucose (IFG), type 2 diabetic mellitus (T2DM) and hypoglycemia were assessed by CGMS.

RESULTS

Five children failed to complete CGMS test. The glucose levels in ISF measured by CGMS were highly correlated with those in capillary samples (r=0.775, P<0.001). However, the correlation between ISF and capillary glucose levels was lower during the first hour than that in the later time period (r=0.722 vs r=0.830), and the ISF glucose levels in 69.62% of children were higher than baseline levels in the initial 1-3 hours. In 79 obese children who finished the CGMS, 2 children had IFG, 2 had IGT, 3 had IFG + IGT, and 2 had T2DM. Nocturnal hypoglycemia was noted during the overnight fasting in 11 children (13.92%).

CONCLUSIONS

Our data suggest that glucose metabolism disorder including hyperglycemia and hypoglycemia is very common in obese children. Further studies are required to improve the precision of the CGMS in children.

Metabolic syndrome and other factors associated with increased risk of diabetes

The prevalence of diabetes has increased dramatically in the last 3 decades. Metabolic syndrome is a strong risk factor for incident diabetes. Among components of metabolic syndrome, obesity and abnormal carbohydrate metabolism are the most significant predictors. Primary care physicians should identify patients at risk and monitor their fasting glucose and/or postprandial glucose to enable timely diagnosis of diabetes and appropriate interventions. Lifestyle interventions that help reduce body weight and pharmacologic interventions that address insulin resistance and/or postprandial glycemia may help prevent diabetes. Intensive cardiovascular risk factor management should be an integral component of any diabetes prevention plan.