The 1-hour post-load glucose level is more effective than HbA1c for screening dysglycemia

International Diabetes Federation Position Statement on the 1-hour post-load plasma glucose for the diagnosis of intermediate hyperglycaemia and type 2 diabetes

Many individuals with intermediate hyperglycaemia (IH), including impaired fasting glycaemia (IFG) and impaired glucose tolerance (IGT), as presently defined, will progress to type 2 diabetes (T2D). There is confirmatory evidence that T2D can be prevented by lifestyle modification and/or medications, in people with IGT diagnosed by 2-h plasma glucose (PG) during a 75-gram oral glucose tolerance test (OGTT). Over the last 40 years, a wealth of epidemiological data has confirmed the superior value of 1-h plasma glucose (PG) over fasting PG (FPG), glycated haemoglobin (HbA1c) and 2-h PG in populations of different ethnicity, sex and age in predicting diabetes and associated complications including death. Given the relentlessly rising prevalence of diabetes, a more sensitive, practical method is needed to detect people with IH and T2D for early prevention or treatment in the often lengthy trajectory to T2D and its complications. The International Diabetes Federation (IDF) Position Statement reviews findings that the 1-h post-load PG ≥ 155 mg/dL (8.6 mmol/L) in people with normal glucose tolerance (NGT) during an OGTT is highly predictive for detecting progression to T2D, micro- and macrovascular complications, obstructive sleep apnoea, cystic fibrosis-related diabetes mellitus, metabolic dysfunction-associated steatotic liver disease, and mortality in individuals with risk factors. The 1-h PG of 209 mg/dL (11.6 mmol/L) is also diagnostic of T2D. Importantly, the 1-h PG cut points for diagnosing IH and T2D can be detected earlier than the recommended 2-h PG thresholds. Taken together, the 1-h PG provides an opportunity to avoid misclassification of glycaemic status if FPG or HbA1c alone are used. The 1-h PG also allows early detection of high-risk people for intervention to prevent progression to T2D which will benefit the sizeable and growing population of individuals at increased risk of T2D. Using a 1-h OGTT, subsequent to screening with a non-laboratory diabetes risk tool, and intervening early will favourably impact the global diabetes epidemic. Health services should consider developing a policy for screening for IH based on local human and technical resources. People with a 1-h PG ≥ 155 mg/dL (8.6 mmol/L) are considered to have IH and should be prescribed lifestyle intervention and referred to a diabetes prevention program. People with a 1-h PG ≥ 209 mg/dL (11.6 mmol/L) are considered to have T2D and should have a repeat test to confirm the diagnosis of T2D and then referred for further evaluation and treatment. The substantive data presented in the Position Statement provides strong evidence for redefining current diagnostic criteria for IH and T2D by adding the 1-h PG.

Prediabetes and Cardiometabolic Risk: The Need for Improved Diagnostic Strategies and Treatment to Prevent Diabetes and Cardiovascular Disease

The progression from prediabetes to type-2 diabetes depends on multiple pathophysiological, clinical, and epidemiological factors that generally overlap. Both insulin resistance and decreased insulin secretion are considered to be the main causes. The diagnosis and approach to the prediabetic patient are heterogeneous. There is no agreement on the diagnostic criteria to identify prediabetic subjects or the approach to those with insufficient responses to treatment, with respect to regression to normal glycemic values or the prevention of complications. The stratification of prediabetic patients, considering the indicators of impaired fasting glucose, impaired glucose tolerance, or HbA1c, can help to identify the sub-phenotypes of subjects at risk for T2DM. However, considering other associated risk factors, such as impaired lipid profiles, or risk scores, such as the Finnish Diabetes Risk Score, may improve classification. Nevertheless, we still do not have enough information regarding cardiovascular risk reduction. The sub-phenotyping of subjects with prediabetes may provide an opportunity to improve the screening and management of cardiometabolic risk in subjects with prediabetes.

Early detection of type 2 diabetes risk: limitations of current diagnostic criteria

Type 2 diabetes (T2D) is the leading cause of diabetes worldwide and is increasing rapidly, especially in youth. It accounts for most diabetes deaths in adults ≥20 years old in the Americas, with type 2 diabetes responsible for most of the disease burden. The incidence and burden of type 2 diabetes in adolescents and young adults have risen in recent decades globally. Countries with lower socioeconomic status had the highest incidence and burden, and females generally had higher mortality and disease burden than males at ages <30 years. Early diagnosis and management are crucial to delaying progression, but current diagnostic criteria based on glucose thresholds and glycated hemoglobin have limitations. Recent analyses show that prediabetes increases cancer risk. Better diagnostic criteria are urgently needed to identify high-risk individuals earlier. This article discusses the limitations of current criteria and explores alternative approaches and future research directions.

One-hour glucose is an earlier marker of dysglycemia than two-hour glucose

AIMS

The timing of increase in 1-hour PG and its utility as an earlier predictor of both prediabetes (PreDM) and type 2 diabetes (T2D) compared to 2-hour PG (2 h-PG) are unknown. To evaluate the timing of crossing of the 1 h-PG ≥ 155 mg/dl (8.6 mmol/L) for PreDM and 209 mg/dl (11.6 mmol/L) for T2D and respective current 2 h-PG thresholds of 140 mg/dl (7.8 mmol/L) and 200 mg/dl (11.1 mmol/L).

METHODS

Secondary analysis of 201 Southwest Native Americans who were followed longitudinally for 6-10 years and had at least 3 OGTTs.

RESULTS

We identified a subset of 43 individuals who first developed PreDM by both 1 h-PG and 2 h-PG criteria during the study. For most (32/43,74%), 1 h-PG ≥ 155 mg/dl was observed before 2 h-PG reached 140 mg/dl (median [IQR]: 1.7 [-0.25, 4.59] y; mean ± SEM: 5.3 ± 1.9 y). We also identified a subset of 33 individuals who first developed T2D during the study. For most (25/33, 75%), 1 h-PG reached 209 mg/dl earlier (median 1.0 [-0.56, 2.02] y; mean ± SEM: 1.6 ± 0.8 y) than 2 h-PG reached 200 mg/dl, diagnostic of T2D.

CONCLUSIONS

1 h-PG ≥ 155 mg/dl is an earlier marker of elevated risk for PreDM and T2D than 2 h-PG ≥ 140 mg/dl.

Value of 1-Hour Plasma Glucose During an Oral Glucose Tolerance Test in a Multiethnic Cohort of Obese Children and Adolescents

One hour plasma glucose (1-hr PG) concentration during an oral glucose tolerance test (OGTT) is steadily emerging as an independent predictor of type 2 diabetes (T2D).

Methods

We applied the current cut off thresholds reported in the pediatric literature for the 1-hr PG, 132.5 (7.4 mmol/l) and 155 mg/dL (8.6 mmol/l) during an OGTT, to report abnormal glucose tolerance (AGT) using ROC curve analyses. We determined the empirical optimal cut point for 1-hr PG for our multi ethnic cohort using the Youden Index.

Results

About 1-hour and 2-hours plasma glucose showed the highest predictive potential based on Areas under the curve (AUC) values of 0.91 [CI: 0.85, 0.97] and 1 [CI: 1, 1], respectively. Further comparison of the ROC curves of the 1-hour and 2-hour PG measurements as predictors of an abnormal OGTT showed that their associated AUCs differed significantly (X²(1) = 9.25, P < .05). Using 132.5 mg/dL as the cutoff point for plasma glucose at 1-hour yielded a ROC curve with an AUC of 0.796, a sensitivity of 88%, and a specificity of 71.2%. Alternatively, the cutoff point of 155 mg/dL resulted in a ROC AUC of 0.852, a sensitivity of 80%, and a specificity of 90.4%.

Conclusion

Our cross-sectional study affirms that the 1-hr PG can identify obese children and adolescents at increased risk for prediabetes and/or T2D with almost the same accuracy as a 2-hr PG. In our multi-ethnic cohort, a 1-hr PG ⩾ 155 mg/dL (8.6 mmol/l) serves as an optimal cut-point, using the estimation of the Youden index with AUC of 0.86 and sensitivity of 80%.We support the petition to consider the 1-hr PG as integral during an OGTT, as this adds value to the interpretation of the OGTT beyond the fasting and 2-hr PG.

The Triglycerides and Glucose (TyG) Index Is Associated with 1-Hour Glucose Levels during an OGTT

BACKGROUND AND OBJECTIVES

Among individuals with normal glucose tolerance (NGT), subjects with high levels of plasma glucose (≥155 mg/dL) at sixty minutes during an oral glucose tolerance test (1h-OGTT) are at an increased risk of developing type 2 diabetes. We investigated the association between the triglycerides and glucose (TyG) index, a novel marker of insulin resistance, with 1h-OGTT glucose plasma concentrations.

MATERIAL AND METHODS

1474 non-diabetic Caucasian subjects underwent a 75 g OGTT and were divided into two groups according to the cutoff 1h-OGTT plasma glucose < 155 mg/dL (NGT-1h-low) and ≥ 155 mg/dL (NGT-1h-high). The TyG index was calculated as ln [fasting triglycerides (milligrams per deciliter) × fasting blood glucose (milligrams per deciliter)/2]. Multivariable linear and logistic regression analyses were used to establish the contribution of the TyG index to the variability of 1h-OGTT glucose, and how the former affected the risk of being NGT-1h-high.

RESULTS

1004 individuals were NGT-1h-low and 470 were NGT-1h-high. The TyG index was higher for NGT-1h-high (p = 0.001) individuals, and it was an independent factor influencing 1h-OGTT glycemia (β = 0.191, p < 0.001) after correcting for age, sex, and BMI. The TyG index was the strongest marker associated with the risk of being NGT-1h-high (OR = 1.703, CI 95% 1.34-2.17, p < 0.001) when compared with FPG (OR = 1.054, CI 95% 1.04-1.07, p < 0.001) and the HOMA-IR (OR = 1.156, CI 95% 1.08-1.23, p < 0.001).

CONCLUSIONS

Our study demonstrated that the TyG index, an efficient and cost-effective marker of insulin resistance, is associated with the variability of early post-challenge glucose levels and is an independent marker of being NGT-1h-high.

1-h post-load plasma glucose for detecting early stages of prediabetes

Prediabetes is a very prevalent condition associated with an increased risk of developing diabetes and/or other chronic complications, in particular cardiovascular disorders. Early detection is therefore mandatory since therapeutic interventions may limit the development of these complications. Diagnosis of prediabetes is currently based on glycemic criteria (fasting plasma glucose (PG), and/or glycemia at 120 min during a 75 g oral glucose tolerance test (OGTT) and/or glycated hemoglobin (HbA1c). Accumulating longitudinal evidence suggests that a 1-hour PG ≥155 mg/dl (8.6 mmol/l) during the OGTT is an earlier marker of prediabetes than fasting PG, 2-h post-load PG, or HbA1c. There is substantial evidence demonstrating that the 1-h post-load PG is a more sensitive predictor of type 2 diabetes, cardiovascular disease, microangiopathy and mortality compared with conventional glucose criteria. The aim of this review is to highlight the paramount importance of detecting prediabetes early in its pathophysiological course. Accordingly, as recommended by an international panel in a recent petition, 1-h post-load PG could replace current criteria for diagnosing early stages of "prediabetes" before prediabetes evolves as conventionally defined.

Saving time by replacing the standardised two-hour oral glucose tolerance test with a one-hour test: Validation of a new screening algorithm in patients with coronary artery disease from the ESC-EORP EUROASPIRE V registry

AIMS

An oral glucose tolerance test (OGTT) combining fasting (FPG) and 2-hour plasma glucose (2hPG) is the most sensitive method for detecting type 2 diabetes (T2DM). Since it is considered time-consuming, we aim at validating a previously proposed screening algorithm based on a 1-hour plasma glucose (1hPG) with a 12 mmol/L threshold.

METHODS

Nine-hundred-eighteen patients with coronary artery disease (CAD) without known T2DM from the EUROASPIRE V cross-sectional survey underwent an OGTT. The reference for T2DM was 2hPG ≥ 11.1 mmol/L. T2DM diagnosis by HbA1c ≥ 6.5%(48 mmol/mol), FPG ≥ 7.0 mmol/L, and 1hPG ≥ 12 mmol/L were compared with the outcome of 2hPG.

RESULTS

Mean FPG, HbA1c and 2hPG were 6.1 mmol/L, 5.6%(38 mmol/mol) and 7.8 mmol/L respectively. Ninety-six patients (10%) were diagnosed with T2DM according to 2hPG. Using this definition, in the group with FPG < 6.5 mmol/L and 1hPG < 12 only 5 (1%) were misdiagnosed as false negatives. All patients with a FPG > 8.0 mmol/L and 1hPG > 15.0 mmol/L were identified as having T2DM. According to the algorithm, in 79% of patients T2DM could be excluded by combining FPG < 6.5 mmol/L and 1hPG < 12 mmol/L.

CONCLUSIONS

T2DM Screening by means of an algorithm combining FPG and 1hPG limits the demand of a 2hOGTT in 79% of CAD patients without known T2DM. HbA1c did not add to the information derived from this algorithm.

Effects of Diet and Exercise Interventions to Prevent Gestational Diabetes Mellitus in Pregnant Women With High-Risk Factors in China: A Randomized Controlled Study

This is a randomized controlled study to determine whether diet and exercise interventions can reduce the incidence of gestational diabetes mellitus (GDM) in pregnant women with high-risk factors. Ninety-four pregnant women were randomly divided into the intervention (n = 47) and control (n = 47) groups. A diet and exercise program was provided for the intervention group by researchers and was adjusted every 2 weeks by outpatient or WeChat intervention. The control group only received the routine health management in the hospital. Follow-up continued until the birth of the baby. The incidence of GDM (23.9%) in the intervention group was lower than in the control group (51.1%) (p = .007). Weight gain did not differ significantly between the two groups throughout pregnancy (p = .572). It is concluded that diet and exercise interventions can reduce the incidence of GDM in pregnant women with high-risk factors.

One-hour plasma glucose concentration can identify elderly Chinese male subjects at high risk for future type 2 diabetes mellitus: A 20-year retrospective and prospective study

AIM

There have been few reports regarding the association between 1 h-PG concentration and type 2 diabetes mellitus (T2DM) in the elderly. This study was performed to assess the efficacy of 1 h-PG and 2 h-PG values in predicting future risk of T2DM in elderly.

METHODS

The study population consisted of 928 male volunteers ≥ 55 years old without diabetes who were involved in a retrospective-prospective cohort study over 20 years with a baseline fasting plasma glucose (FPG) and OGTT that included measurement of 1 h-PG and 2 h-PG. The predictive capabilities of FPG and 1 h-PG, 2 h-PG values obtained during OGTT alone and added to a clinical prediction model consisting of traditional diabetes risk factors were assessed.

RESULTS

Overall, 577 of all the 928 study participants (62%) developed T2DM over the 20-year follow-up. 1 h-PG and 2 h-PG values predicted T2DM and remained independent predictors of T2DM after adjusting for various traditional risk factors [HR = 1.269 (95% CI = 1.214-1.327), P < 0.001; HR = 1.269 (95% CI = 1.179-1.366), P < 0.001, respectively]. C-statistics for 1-h PG (C-statistics 0.794 [95% CI 0.765-0.823]) was significantly greater than that for 2-h PG (C-statistic 0.747 [95% CI 0.716-0.779]) in models adjusting for various traditional risk factors. 1 h-PG had the greatest area under the ROC curve (AUC, 0.766), which was greater than that of 2 h-PG (0.719).

CONCLUSIONS

1 h-PG is useful as a predictor of future development of T2DM independently of traditional risk factors in an elderly Chinese male population.

The Oral Glucose Tolerance Test: 100 Years Later

For over 100 years, the oral glucose tolerance test (OGTT) has been the cornerstone for detecting prediabetes and type 2 diabetes (T2DM). In recent decades, controversies have arisen identifying internationally acceptable cut points using fasting plasma glucose (FPG), 2-h post-load glucose (2-h PG), and/or HbA1c for defining intermediate hyperglycemia (prediabetes). Despite this, there has been a steadfast global consensus of the 2-h PG for defining dysglycemic states during the OGTT. This article reviews the history of the OGTT and recent advances in its application, including the glucose challenge test and mathematical modeling for determining the shape of the glucose curve. Pitfalls of the FPG, 2-h PG during the OGTT, and HbA1c are considered as well. Finally, the associations between the 30-minute and 1-hour plasma glucose (1-h PG) levels derived from the OGTT and incidence of diabetes and its complications will be reviewed. The considerable evidence base supports modifying current screening and diagnostic recommendations with the use of the 1-h PG. Measurement of the 1-h PG level could increase the likelihood of identifying high-risk individuals when the pancreatic ß-cell function is substantially more intact with the added practical advantage of potentially replacing the conventional 2-h OGTT making it more acceptable in the clinical setting.

One-hour plasma glucose combined with skin autofluorescence identifies subjects with pre-diabetes: the DIAPASON study

INTRODUCTION

The major challenge for diabetes prevention is early identification of individuals at risk to allow for implementation of measures to delay the onset of future disease. Measures such as fasting plasma glucose (FPG), 2-hour plasma glucose (2hPG), and glycosylated hemoglobin (HbA1c) are equally appropriate for identifying pre-diabetes and diabetes, but do not all identify the disease in the same individual. We tested the utility of a diagnostic method combining FPG, 2hPG and HbA1c for early evaluation and easy identification of pre-diabetes.

RESEARCH DESIGN AND METHODS

531 subjects underwent skin autofluorescence (SAF) and glycemia analyses. We created two classification groups based on the American Diabetes Association diagnosis guidelines: (1) based on 2hPG and (2) based on a new combination of three glycemia parameters (the three-criteria strategy (3-c)). Logistic regression modeling was used to estimate the associations.

RESULTS

SAF showed high associations for both 3-c definition and 2hPG definition alone. These associations appeared stronger in 3-c than those in 2hPG. The non-invasive SAF measurement outperformed 2hPG in the detection of dysglycemia or pre-diabetes. Stepwise selections identified 1-hour postload glucose (1hPG) as variable identifying pre-diabetes using the 2hPG criterion, and the model based on 1hPG plus SAF appeared to be the best association using the 3-c strategy.

CONCLUSIONS

1hPG coupled with SAF showed a strong association in the evaluation of pre-diabetes using the 3-c method.

Gamma-Polyglutamic Acid-Rich Natto Suppresses Postprandial Blood Glucose Response in the Early Phase after Meals: A Randomized Crossover Study

We evaluated the suppressive effects of high-gamma-polyglutamic acid (γ-PGA) natto on postprandial blood glucose level and insulin response. After confirming the eligibility of candidates using a pre-selective test with packaged white rice, a meal loading test including low- or high-γ-PGA natto (with 57.6 mg (LPGA) and 439.6 mg (HPGA) of γ-PGA, respectively) was conducted in men aged 20 to 70 years (n = 29) and postmenopausal women aged ≤70 years (n = 7). On each examination day, blood samples were obtained after they fasted overnight and for 120 min after test meal loading. The primary outcome of this study was the difference between the measurements of the incremental area under the curve (IAUC) for blood glucose 0 to 30 min after loading of LPGA and HPGA meals. The IAUCs for blood glucose and insulin after the HPGA meal were lower than those after the LPGA meal within 45 min (0 to 15 and 0 to 30 min: p < 0.001, 0 to 45 min: p < 0.01) and 1 h (all p < 0.001) of loading, respectively. The suppressive effects of HPGA natto on postprandial glucose response in the early phase, which possibly relates to the risk of dysglycemia and cardiovascular disease, were clarified.

Pitfalls of HbA1c in the Diagnosis of Diabetes

Many health care providers screen high-risk individuals exclusively with an HbA1c despite its insensitivity for detecting dysglycemia. The 2 cases presented describe the inherent caveats of interpreting HbA1c without performing an oral glucose tolerance test (OGTT). The first case reflects the risk of overdiagnosing type 2 diabetes (T2D) in an older African American male in whom HbA1c levels, although variable, were primarily in the mid-prediabetes range (5.7-6.4% [39-46 mmol/mol]) for many years although the initial OGTT demonstrated borderline impaired fasting glucose with a fasting plasma glucose of 102 mg/dL [5.7 mmol/L]) without evidence for impaired glucose tolerance (2-hour glucose ≥140-199 mg/dl ([7.8-11.1 mmol/L]). Because subsequent HbA1c levels were diagnostic of T2D (6.5%-6.6% [48-49 mmol/mol]), a second OGTT performed was normal. The second case illustrates the risk of underdiagnosing T2D in a male with HIV having normal HbA1c levels over many years who underwent an OGTT when mild prediabetes (HbA1c = 5.7% [39 mmol/mol]) developed that was diagnostic of T2D. To avoid inadvertent mistreatment, it is therefore essential to perform an OGTT, despite its limitations, in high-risk individuals, particularly when glucose or fructosamine and HbA1c values are discordant. Innate differences in the relationship between fructosamine or fasting glucose to HbA1c are demonstrated by the glycation gap or hemoglobin glycation index.

Evaluation of the relationship between the one-hour plasma glucose concentration and beta-cell functions and cardiometabolic parameters during oral glucose tolerance test in obese children and adolescents

Background In this study, we aimed to evaluate the relationship between the 1-h plasma glucose (PG) level in the oral glucose tolerance test (OGTT) and conventional glycemic parameters, indices evaluating beta-cell functions, and cardiometabolic risk factors. Methods The records of 532 obese patients who were followed up in the Pediatric Endocrinology Polyclinic and who underwent standard OGTT were evaluated retrospectively. All patients were divided into two groups according to OGTT data as the 1-h plasma glucose concentration <155 mg/dL (n=329) and ≥155 mg/dL (n=203). Patients with normal glucose tolerance (NGT) were divided into two groups according to the 1-h PG level, as 218 patients with NGT 1 h-low (<155 mg/dL) and 53 patients with high NGT 1 h-high (≥155 mg/dL). Results There was a statistically significant difference between the lipid profiles of individuals with NGT 1 h-low (<155 mg/dL) and individuals with NGT 1 h-high (≥155 mg/dL) (p<0.001). Total cholesterol, LDL cholesterol, and triglyceride levels were higher, while HDL cholesterol levels were lower in individuals with NGT 1 h-high (≥155 mg/dL). The indices evaluating beta-cell functions were significantly higher in individuals with NGT 1 h-low (<155 mg/dL). Conclusion As a result, a plasma glucose concentration above or equal to 155 mg/dL at 1 h during an OGTT is associated with a worse clinical phenotype characterized by changes in insulin sensitivity and β-cell function. Therefore, this threshold value can predict the progression of prediabetes in obese young people with NGT.

Evaluating the 1-h post-load glucose level to predict future type 2 diabetes

AIMS

To evaluate the predictive ability of 2-h post-load glucose level in addition to fasting and 1-h glucose levels in predicting the risk of type 2 diabetes.

METHODS

We examined a prospective population-based cohort study of 654 subjects without type 2 diabetes at baseline. All subjects underwent an oral glucose tolerance test (OGTT), with measurement of glucose at 0, 60, and 120 min at baseline, and after 12 years in a follow-up survey. We evaluated the predictive properties of fasting, 1- and 2-h post-load glucose levels by comparing the areas under the receiver-operating characteristic (ROC) curve.

RESULTS

We found that 2-h glucose concentration in the prediction model with fasting and 1-h glucose levels did not significantly increase the predictability of type 2 diabetes compared to a model only including fasting and 1-h glucose levels (AUC 0.83 vs. AUC 0.82, respectively; p = 0.23). The area under the ROC curve was the largest for 1-h glucose level (AUC 0.81), compared to fasting (AUC 0.71; p < 0.01) and 2-h glucose levels (AUC 0.72; p = 0.01).

CONCLUSIONS

Adding 2-h glucose to the model with fasting and 1-h glucose levels did not improve the predictability of new onset type 2 diabetes.

Update on the current modalities used to screen high risk youth for prediabetes and/or type 2 diabetes mellitus

The modalities currently employed to screen for type 2 diabetes mellitus (T2DM)/prediabetes are HbA1c, fasting plasma glucose (FPG), and 2-hour plasma glucose (PG) during an oral glucose tolerance test (OGTT). The purpose of this review is to highlight the positive qualities and pitfalls of these diagnostic modalities and reflect on the most reasonable and effective approach to screen high risk youth. Given its inherent preanalytical advantages, glycated hemoglobin (HbA1c) continues to be the preferred diagnostic modality used by pediatricians to screen high risk youth. However, when the three aforementioned tests are performed in youths of different races/ethnicities, discrepant results for T2DM/prediabetes are observed. The prevalence rates for T2DM vary from 0.53% in Chinese youth (including youth of all body mass indexes) to 18.3% in high-risk, overweight, obese Korean youth. Moreover, the FPG is abnormal (&gt;100 less than &lt;126 mg/dL) in 15% of Korean youth versus 8.7% of Chinese youth. The prevalence rates for prediabetes are 1.49% in Chinese youth versus 21% in Emirati youth (HbA1c, 5.7%-6.4%). The coefficient of agreement, k, between these screening tests for T2DM are fair, 0.45-0.5 across all youth. However, using HbA1c as a comparator, the agreement is weak with FPG (k=0.18 in German youth versus k=0.396 in Korean youth). The American Diabetes Association (ADA) Standards of Medical Care Guidelines define "high risk youth" who need to be tested for T2DM and/or prediabetes. OGTT and HbA1c do not always detect T2DM in similar individuals. HbA1c may not be an ideal test for screening Hispanic and African American youth. FPG and OGTT are suitable screening tests for youth of ethnic minorities and those with cystic fibrosis or hemoglobinopathies. Performing all three tests either together or sequentially may be the only way to encompass all youth who have aberrations in different aspects of glucose homeostasis.

Cardiometabolic importance of 1-h plasma glucose in obese subjects

Background/objectives

To study the importance and clinical usefulness of the 1-h plasma glucose (1hPG) in a Caucasian obese population with regard to the presence of prediabetes, diabetes, and metabolic syndrome (MetS).

Subjects/methods

We conducted a cross-sectional study of 2439 overweight or obese subjects. All received an oral glucose tolerance test (OGTT) using the American Diabetes Association criteria. ROC-curves were used to compare the sensitivity and (1-specificity) of 1hPG versus FPG and 2hPG to diagnose prediabetes and diabetes.

Results

Of 2439 patients (72.1% female) (age 43 ± 13 years, BMI 37.9 (34.6–41.6) kg/m²), 1262 (51.7%) had a 1hPG ≥ 155 mg/dL. The prevalence of prediabetes was 33.8% and of diabetes 9.8%. In these 240 diabetic patients, only 1.6% (four patients) did not show a 1hPG ≥ 155 mg/dL. Subjects with 1hPG ≥ 155 mg/dL were more insulin resistant (p < 0.001), had a higher waist (p < 0.001), visceral adipose tissue (VAT) (p < 0.001), systolic blood pressure (p < 0.001), microalbuminuria (p < 0.001), PAI-1 (p < 0.001), and worse lipid profile (p < 0.001) than subjects with 1hPG < 155 mg/dL. MetS was present in 64.1% of subjects with 1hPG ≥ 155 mg/dL versus 42.5% of subjects with 1hPG < 155 mg/dL (p < 0.001). In the group with 1hPG ≥ 155 mg/dL 32.6% had a normal glucose tolerance (NGT), 48.9% had prediabetes, and 18.5% was diagnosed with T2DM compared to 81.7% NGT, 17.7% prediabetes, and 0.6% T2DM in subjects with 1hPG < 155 mg/dL (p < 0.001). Among NGT subjects, 30.0% had a 1hPG ≥ 155 mg/dL and showed higher HOMA-IR (p = 0.008), VAT (p < 0.001), blood pressure (p < 0.001), and worse lipid profile (p = 0.001). Compared to 1hPG < 155 mg/dL, the sensitivity and specificity of 1hPG ≥ 155 mg/dL of prediabetes were 74.8% and 60.0% and for diabetes 97.1% and 53.2%, respectively.

Conclusions

This study supports the role of 1hPG value as a valuable tool in the detection of obese subjects at high risk for T2DM and MetS.

The STOP DIABETES study: when prevention works

Although many drugs are now available, a large effort is still needed to prevent diabetes. The STOP DIABETES study evaluated individuals at risk for type 2 diabetes (T2D) by a 2-h 75-g oral glucose tolerance test (OGTT). Based on the three main defective physiological responses, subjects were stratified as at low, intermediate, or high risk, and treated accordingly with lifestyle modifications and drugs. Participants at intermediate and high risk experienced the greatest reduction of T2D conversion. Interestingly, a group of individuals developing T2D presented a normal glucose tolerance at baseline, but a 1-h plasma glucose concentration > 155 mg/dL. These results are critical as prediabetes can increase the incidence of cardiovascular disease. Considering the timeframe between the first defects in glucose metabolism and the manifestation of diabetes complications, the effort to tackle the glycemic impairment as soon as possible represents an outstanding task to reduce the incidence of diabetes. Ideally, the earlier glycemic alterations are recognized, the lesser armamentarium needs to be used, and the lower is the expense in terms of drugs, complications, and related events and costs. Finally, a wealth of studies clearly demonstrated the importance of 1-h plasma glucose concentration, which has been proposed as an adjunctive diagnostic tool to detect prediabetes earlier. In conclusion, by an OGTT, a lot of individuals at risk for T2D may be detected when the central role for the 1-h plasma glucose concentration is also considered. Consequently, these subjects would be treated early and with less drugs and delay T2D complications.

1-Hour Post-OGTT Glucose Improves the Early Prediction of Type 2 Diabetes by Clinical and Metabolic Markers

CONTEXT

Early prediction of dysglycemia is crucial to prevent progression to type 2 diabetes. The 1-hour postload plasma glucose (PG) is reported to be a better predictor of dysglycemia than fasting plasma glucose (FPG), 2-hour PG, or glycated hemoglobin (HbA1c).

OBJECTIVE

To evaluate the predictive performance of clinical markers, metabolites, HbA1c, and PG and serum insulin (INS) levels during a 75-g oral glucose tolerance test (OGTT).

DESIGN AND SETTING

We measured PG and INS levels at 0, 30, 60, and 120 minutes during an OGTT in 543 participants in the Botnia Prospective Study, 146 of whom progressed to type 2 diabetes within a 10-year follow-up period. Using combinations of variables, we evaluated 1527 predictive models for progression to type 2 diabetes.

RESULTS

The 1-hour PG outperformed every individual marker except 30-minute PG or mannose, whose predictive performances were lower but not significantly worse. HbA1c was inferior to 1-hour PG according to DeLong test P value but not false discovery rate. Combining the metabolic markers with PG measurements and HbA1c significantly improved the predictive models, and mannose was found to be a robust metabolic marker.

CONCLUSIONS

The 1-hour PG, alone or in combination with metabolic markers, is a robust predictor for determining the future risk of type 2 diabetes, outperforms the 2-hour PG, and is cheaper to measure than metabolites. Metabolites add to the predictive value of PG and HbA1c measurements. Shortening the standard 75-g OGTT to 1 hour improves its predictive value and clinical usability.

Performance of HbA1c versus oral glucose tolerance test (OGTT) as a screening tool to diagnose dysglycemic status in high-risk Thai patients

BACKGROUND

Dysglycemic status defined by prediabetes and diabetes is known to be related with future risk of diabetic complications and cardiovascular diseases. Herein, we aimed to determine the diagnostic accuracy of glycated hemoglobin (HbA1c) when compared with oral glucose tolerance test (OGTT) as a reference test in identifying dysglycemic status among high-risk Thai patients receiving care in an out-patient setting.

METHODS

An 11-year retrospective cross-sectional study of high-risk Thai patients who underwent OGTT during 2007-2017 was analysed. The OGTT was used as a reference test to identify subjects of dysglycemic status. The diagnostic accuracy of HbA1c and the agreement between HbA1c and OGTT were examined. Validated Thai diabetes risk score, Thai cardiovascular risk score (Thai CV risk score), and visceral fat area (VFA) were also compared in each glycemic status from OGTT as surrogate markers for future diabetes and cardiovascular diseases.

RESULTS

A total of 512 subjects (females 60.5%, mean age of 50.3 ± 12.7 years, BMI of 26.5 ± 4.6 kg/m2) were reviewed. Normal glucose tolerance (NGT) was found in 220 patients (43.0%), impaired glucose tolerance (IGT) in 191 patients (37.3%), and diabetes in 101 patients (19.7%). The prevalence of diabetes using OGTT was approximately two times higher than those defined by HbA1c (19.7% versus 11.1%). There were poor agreements between the classifications of prediabetes and diabetes defined by OGTT and HbA1c (Cohen's Kappa 0.154 and 0.306, respectively). Using a cut-off value for HbA1c ≥6.5% as a threshold for HbA1c-defined criteria of diabetes, sensitivity was 32% (95% CI 23-41%) and specificity was 94% (95% CI 92-96%). The optimal cut-off HbA1c value for detecting diabetes by Youden's index was at HbA1c 6.2%. Thai CV risk score was much higher among the OGTT-defined diabetes group when compared with the NGT group (median score 10 vs. 3, p-value < 0.001).

CONCLUSIONS

Despite the practicality and validity of HbA1c as a diagnostic test, our study suggested that HbA1c as a screening tool for diabetes in high-risk Thai patients is much inferior to OGTT. With limitations of HbA1c, physicians should continue to advocate OGTT as a screening tool for the identification of dysglycemic status in high-risk Thai patients.

Petition to replace current OGTT criteria for diagnosing prediabetes with the 1-hour post-load plasma glucose ≥ 155 mg/dl (8.6 mmol/L)

Many individuals with prediabetes, as presently defined, will progress to diabetes (T2D) despite the considerable benefit of lifestyle modification. Therefore, it is paramount to screen individuals at increased risk with a more sensitive method capable of identifying prediabetes at an even earlier time point in the lengthy trajectory to T2D. This petition reviews findings demonstrating that the 1-hour (1-h) postload plasma glucose (PG) ≥ 155 mg/dl (8.6 mmol/L) in those with normal glucose tolerance (NGT) during an oral glucose tolerance test (OGTT) is highly predictive for detecting progression to T2D, micro- and macrovascular complications and mortality in individuals at increased risk. Furthermore, the STOP DIABETES Study documented effective interventions that reduce the future risk of T2D in those with NGT and a 1-h PG ≥ 155 mg/dl (8·6 mmol/L). The 1-h OGTT represents a valuable opportunity to extend the proven benefit of diabetes prevention to the sizeable and growing population of individuals at increased risk of progression to T2D. The substantial evidence provided in this petition strongly supports redefining current diagnostic criteria for prediabetes with the elevated 1-h PG level. The authors therefore advocate a 1-h OGTT to detect prediabetes and hence, thwart the global diabetes epidemic.

Fasting plasma glucose is a stronger predictor of diabetes than triglyceride-glucose index, triglycerides/high-density lipoprotein cholesterol, and homeostasis model assessment of insulin resistance: Tehran Lipid and Glucose Study

AIMS

To compare the impact of triglyceride-glucose index (TyG-index), the product of fasting plasma glucose (FPG) and triglycerides (TG) with FPG, 2 h post-challenge plasma glucose (2 h-PCPG), TG/high-density lipoprotein cholesterol (TG/HDL-C), and homeostasis model assessment of insulin resistance (HOMA-IR) indices for prediction of type 2 diabetes (T2D) in Iranian adults during a median follow-up of 12 years.

METHODS

Study population included 4419 (1858 men) subjects with mean age of 40.6 ± 13.2 years. Multivariable Cox proportional hazard models were used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for each 1-standard deviation increase in each predictor. Areas under the receiver operating characteristics curves (AUC) and 95% CIs were calculated.

RESULTS

During follow-up, 215 men and 288 women developed T2D. The multivariable HRs for FPG, 2 h-PCPG, TyG-index, HOMA-IR, HOMA2-IR, and TG/HDL-C were 2.20, 1.97, 1.71, 1.33, 1.30, and 1.35 in men and 2.13, 2.11, 1.44, 1.37, 1.32, and 1.36 in women (all P < 0.001). Among the total population, the AUC for FPG [0.752 (0.727-0.776)] was similar to 2 h-PCPG but higher than TyG-index [0.697 (0.673-0.720)], TG/HDL-C [0.644 (0.620-0.669)], HOMA-IR [0.684 (0.659-0.710)], and HOMA2-IR [0.656 (0.630-0.682)]. In men, AUC of TyG-index was higher than TG/HDL-C but did not differ with HOMA-IR indices. In women, the AUC of TyG-index was higher than HOMA2-IR and TG/HDL-C, but was similar to that of HOMA-IR.

CONCLUSIONS

FPG is a stronger predictor of T2D than the TyG-index, TG/HDL-C, and HOMA-IR indices. Although TyG-index was better than TG/HDL-C in both genders, it did not rank above HOMA-IR.

One-Hour Postload Hyperglycemia: Implications for Prediction and Prevention of Type 2 Diabetes

CONTEXT

Recently, a value of 1-hour postload glucose concentration (1-h-PG) ≥155 mg/dL (8.6 mmol/L) in individuals with normal glucose tolerance (NGT) has been found to be associated with an increased risk for future type 2 diabetes mellitus (T2DM). In this review, we analyze the implication of 1-h-PG determination in prediction of T2DM and cardiovascular disease.

DESIGN

A literature search was performed using MEDLINE. We included all English studies published up to February 2018 in peer-reviewed journals that examined the relationship between 1-h-PG and diabetes, cardiometabolic alterations, organ damage, and cardiovascular disease.

RESULTS

Several longitudinal studies have consistently shown that 1-h-PG ≥155 mg/dL can recognize individuals at increased risk for future T2DM among subjects with NGT. Additionally, we describe the pathophysiological abnormalities associated with 1-h-PG ≥155 mg/dL including impaired insulin sensitivity, β-cell dysfunction, and increased glucose intestinal absorption, which are known to be involved in T2DM pathogenesis. Importantly, numerous studies have demonstrated that a value of 1-h-PG ≥155 mg/dL in individuals with NGT is not only linked to an increased risk for future T2DM, but also able to identify those having a worse cardiovascular phenotype and an increased risk of adverse cardiovascular outcomes.

CONCLUSIONS

Although 1-h-PG determination is not currently recommended by the American Diabetes Association for identifying high-risk individuals, the available evidence indicates that a value of 1-h-PG ≥155 mg/dL may be a useful tool to recognize, among subjects with NGT, those at increased risk of T2DM and cardiovascular disease.

Higher HbA1c and/or glucose levels alter the association patterns between glycated hemoglobin and fasting glucose levels

AIMS

To verify the correlations between HbA1c and fasting glucose levels.

METHODS

A cross-sectional study with 14,249 Chinese subjects. Objective was evaluated in pooled, age-stratified, HbA1c and fasting glucose-stratified populations.

RESULTS

In pooled populations, the Pearson correlation coefficients (PCCs) of males and females were 0.684 (P < 0.001) and 0.800 (P < 0.001), respectively. HbA1c and fasting glucose maintained significant correlations within the group with HbA1c < 6.5% and glucose <7.0 mmol/L and the group with HbA1c ≥ 6.5% and glucose ≥7.0 mmol/L in both males (PCC: 0.342, P < 0.001; and PCC: 0.765, P < 0.001, respectively) and females (PCC: 0.318, P < 0.001 and PCC: 0.788, P < 0.001, respectively). The slopes increased from the group with HbA1c < 6.5% and glucose <7.0 mmol/L to the group with HbA1c ≥ 6.5% and glucose ≥7.0 mmol/L in both males (0.26-0.44) and females (0.31-0.46). Linear regression analysis showed that fasting glucose and age were two common factors positively associated with HbA1C, and red blood cell count and red cell distribution width were two common factors negatively associated with HbA1c in both males and females with HbA1c < 6.5% and glucose <7.0 mmol/L. The correlations changed dramatically in the groups with HbA1c ≥ 6.5% and glucose <7.0 mmol/L and HbA1c < 6.5% and glucose ≥7.0 mmol/L.

CONCLUSIONS

High HbA1c and fasting glucose levels greatly altered the associations between HbA1c, glucose and age.

Lessons learned from the 1-hour post-load glucose level during OGTT: Current screening recommendations for dysglycaemia should be revised

This perspective covers a novel area of research describing the inadequacies of current approaches for diagnosing dysglycaemia and proposes that the 1-hour post-load glucose level during the 75-g oral glucose tolerance test may serve as a novel biomarker to detect dysglycaemia earlier than currently recommended screening criteria for glucose disorders. Considerable evidence suggests that a 1-hour post-load plasma glucose value ≥155 mg/dl (8.6 mmol/L) may identify individuals with reduced β-cell function prior to progressing to prediabetes and diabetes and is highly predictive of those likely to progress to diabetes more than the HbA_1c or 2-hour post-load glucose values. An elevated 1-hour post-load glucose level was a better predictor of type 2 diabetes than isolated 2-hour post-load levels in Indian, Japanese, and Israeli and Nordic populations. Furthermore, epidemiological studies have shown that a 1-hour PG ≥155 mg/dl (8.6 mmol/L) predicted progression to diabetes as well as increased risk for microvascular disease and mortality when the 2-hour level was <140 mg/dl (7.8 mmol/L). The risk of myocardial infarction or fatal ischemic heart disease was also greater among subjects with elevated 1-hour glucose levels as were risks of retinopathy and peripheral vascular complications in a Swedish cohort. The authors believe that the considerable evidence base supports redefining current screening and diagnostic recommendations with the 1-hour post-load level. Measurement of the 1-hour PG level would increase the likelihood of identifying a larger, high-risk group with the additional practical advantage of potentially replacing the conventional 2-hour oral glucose tolerance test making it more acceptable in a clinical setting.

The 1-h post-load plasma glucose as a novel biomarker for diagnosing dysglycemia

Identifying the earliest moment for intervention to avert progression to prediabetes and diabetes in high-risk individuals is a substantial challenge. As β-cell function is already compromised in prediabetes, attention should therefore be focused on identifying high-risk individuals earlier in the so-called pre-prediabetes stage. Biomarkers to monitor progression and identify the time point at which β-cell dysfunction occurs are therefore critically needed. Large-scale population studies have consistently shown that the 1-h plasma glucose (1-h PG) ≥ 155 mg/dl (8.6 mmol/l) during the oral glucose tolerance test detected incident type 2 diabetes and associated complications earlier than fasting plasma glucose or 2-h plasma glucose levels. An elevated 1-h PG level appears to be a better alternative to HbA1c [5.7-6.4% (37-47 mmol/mol)] or traditional glucose criteria for identifying high-risk individuals at a stage when ß-cell function is substantially more intact than in prediabetes. Diagnosing high-risk individuals earlier proffers the opportunity for potentially reducing progression to diabetes, development of microvascular complications and mortality, thereby advancing benefit beyond that which has been demonstrated in global diabetes prevention programs.

The 1h post glucose value best predicts future dysglycemia among normal glucose tolerance subjects

AIM

To analyse the OGTT glycemic parameters - fasting, 1h and 2h plasma glucose values singly and in various combinations; with respect to their prediction of future dysglycemia in subjects with normal glucose tolerance (NGT).

METHODS

Electronic medical records of individuals who underwent an OGTT between 1991 and 2016 at a tertiary diabetes centre were analysed. NGT subjects who had at least one more follow up OGTT (n=1356) were selected for the study. Regarding their prediction of future dysglycemia, the glycemic parameters-Fasting plasma glucose (FPG), 1h plasma glucose (1HrPG) and 2h plasma glucose (2HrPG) were analysed separately and also in different combinations. HbA1c and the combined use of HbA1c and FPG were also compared. Receiver operating characteristic (ROC) curve analysis was performed to assess the capability of various glycemic parameters to discriminate between NGT and dysglycemia. The WHO criteria were used to define dysglycemia as the presence of prediabetes (Impaired fasting glucose and/or Impaired glucose tolerance) or diabetes.

RESULTS

318(23.4%) developed prediabetes (median follow up 3.5years) and 134(10%) developed diabetes (median follow up 5.6years). The 1hrPG had a significantly higher AUC (0.684, 0.716) compared to FPG (0.560 and 0.593) and 2hrPG (0.644 and 0.618) for prediabetes and diabetes respectively. Adding the FPG or the 2hrPG to the 1HrPG did not significantly improve the AUC beyond 1HrPG alone. The 1HrPG also predicted diabetes better than HbA1c as well as the combined use of HbA1c and FPG.

CONCLUSION

The 1HrPG value during OGTT is a good predictor of future dysglycemia among NGT subjects.

Elevated 1-h post-challenge plasma glucose levels in subjects with normal glucose tolerance or impaired glucose tolerance are associated with whole blood viscosity

AIM

It has been suggested that glucose levels ≥155 mg/dl at 1-h during an oral glucose tolerance test (OGTT) may predict development of type 2 diabetes and cardiovascular events among adults with normal glucose tolerance (NGT 1 h-high). Studies showed a link between increased blood viscosity and type 2 diabetes. However, whether blood viscosity is associated with dysglycemic conditions such as NGT 1 h-high, impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) is unsettled.

METHODS

1723 non-diabetic adults underwent biochemical evaluation and OGTT. A validated formula based on hematocrit and total plasma proteins was employed to estimate whole blood viscosity. Subjects were categorized into NGT with 1 h glucose <155 mg/dL (NGT-1 h-low), NGT-1 h-high, IFG and/or IGT.

RESULTS

Hematocrit and blood viscosity values appeared significantly higher in individuals with NGT 1 h-high, IFG and/or IGT as compared to NGT 1 h-low subjects. Blood viscosity was significantly correlated with age, waist circumference, blood pressure, HbA1c, fasting, 1- and 2-h post-challenge insulin levels, total cholesterol and low-density lipoprotein, triglycerides, fibrinogen, white blood cell, and inversely correlated with high-density lipoprotein and insulin sensitivity. Of the four glycemic parameters, 1-h post-challenge glucose showed the strongest correlation with blood viscosity (β = 0.158, P < 0.0001) in a multivariate regression analysis model including several atherosclerosis risk factors.

CONCLUSIONS

Our results demonstrate a positive relationship between blood viscosity and 1-h post-challenge plasma glucose. They also suggest that a subgroup of NGT individuals with 1-h post-challenge plasma >155 mg/dl have increased blood viscosity comparable to that observed in subjects with IFG and/or IGT.

Serum 1,5-anhydroglucitol level as a screening tool for diabetes mellitus in a community-based population at high risk of diabetes

AIMS

Early diagnosis of diabetes yields significant clinical benefits; however, currently available diagnostic tools for community-based population are limited. This study aimed to assess the value of serum 1,5-anhydroglucitol (1,5-AG) for the diagnosis and screening of diabetes mellitus in a community-based population at high risk of diabetes.

METHODS

In this diagnostic test, 1170 participants underwent a 75-g oral glucose tolerance test. Venous blood samples were collected for fasting blood glucose (FBG), 2-h postprandial blood glucose (PBG), and glycosylated hemoglobin A1c (HbA1c) measurements. Serum 1,5-AG levels were detected by the GlycoMark assay, and a receiver operating characteristic (ROC) curve was generated to assess their diagnostic value for diabetes.

RESULTS

A total of 298 adults were diagnosed with diabetes, indicating a prevalence of 25.47%. Partial Pearson correlation analysis adjusted for age and body mass index showed that serum 1,5-AG level was negatively correlated with FBG, PBG, and HbA1c (all P < 0.01). Areas under the curves (AUCs) for serum 1,5-AG, FBG, PBG, and HbA1c in identifying diabetes were 0.920, 0.874, 0.933, and 0.887, respectively. According to the ROC curve, the optimal cutoff value of serum 1,5-AG for diagnosing diabetes was 11.18 μg/ml, which yielded a sensitivity of 92.6% and a specificity of 82.3%, respectively. Comparisons between 1,5-AG and HbA1c showed that both the AUC and sensitivity of 1,5-AG were higher than those of HbA1c (both P < 0.01).

CONCLUSIONS

Serum 1,5-AG is a simple and effective marker with high sensitivity and specificity for identifying diabetes in populations at high risk of diabetes.

An elevated 1-h post- load glucose level during the oral glucose tolerance test detects prediabetes

AIM

The objective of the study was to compare the diagnosis of dysglycemic states by conventional oral glucose tolerance test (OGTT) criteria (fasting and 2-h plasma glucose) with the 1-h post-load plasma glucose level.

MATERIAL AND METHODS

34 individuals (mean age: 55±13years; BMI: 27.7±6.3kg/m²) at risk for prediabetes were administered a 75g OGTT. Individuals with normal glucose tolerance (NGT) or prediabetes were identified according to fasting and/or 2-h plasma glucose (PG) concentrations. Subsequently, subjects were divided in 2 groups: group 1 (n=21) with a 1-h PG<155mg/dl and group 2 (n=13) with a 1-h PG≥155mg/dl. HOMA was performed to assess β-cell function and insulin sensitivity.

RESULTS

NGT or prediabetes based on conventional criteria correlated with the 1-h PG<or≥155mg/dl (p<0.001). Moreover, the 1-h PG≥155mg/dl was associated with higher HbA_1c levels (6.1±0.5 vs. 5.5±0.3%, p<0.001) and significantly impaired insulin secretion and hyperbolic product (BxS) on HOMA test vs. 1-h PG<155mg/dl.

CONCLUSION

The 1-h post-load plasma glucose value ≥155mg/dl is strongly associated with conventional criteria for (pre)diabetes and alterations of β-cell function.

Reducing the prevalence of dysglycemia: is the time ripe to test the effectiveness of intervention in high-risk individuals with elevated 1 h post-load glucose levels?

Identifying the earliest time point on the prediabetic continuum is critical to avoid progressive deterioration in β-cell function. Progressively rising glucose levels even within the "normal range" occur considerably late in the evolution to diabetes thus presenting an important opportunity for earlier diagnosis, treatment, and possible reversal. An elevated 1 h postprandial glucose level, not detected by current diagnostic standards, may provide an opportunity for the early identification of those at risk. When the 1 h post-load glucose level is elevated, lifestyle intervention may have the greatest benefit for preserving β-cell function and prevent further progression to prediabetes and diabetes. In view of the considerable consistent epidemiologic data in large disparate populations supporting the predictive capacity of the1 h post-load value for predicting progression to diabetes and mortality, the time is therefore ripe to evaluate this hypothesis in a large, prospective multicenter randomized trial with lifestyle intervention.

One-hour post-load plasma glucose level during the OGTT predicts dysglycemia: Observations from the 24year follow-up of the Israel Study of Glucose Intolerance, Obesity and Hypertension

AIMS

The present study assessed the longitudinal association of an elevated 1-h plasma glucose [1-h-PG >8.6mmol/l (155mg/dl)] with and without impaired glucose tolerance [IGT; 2-h-PG 7.8-11.0mmol/l (140-199mg/dl)] with cumulative incident of diabetes and prediabetes over 24years in a non-diabetic cohort.

METHODS

From 1979 to 1984, 1970 non-diabetic men and women completed an oral glucose tolerance test (OGTT), physical and biochemical measurements as well as a questionnaire related to lifestyle and medical background. During the years 2000-2004, 853 survivors of the original cohort were interviewed and re-examined for glycemic progression.

RESULTS

Individuals with 1-h-PG >8.6mmol/l (155mg/dl) but with 2-h-PG <7.8mmol/l (140mg/dl) had a significantly elevated risk, compared to those with both 1-h-PG ⩽8.6mmol/l (155mg/dl) and 2-h-PG <7.8mmol/l (140mg/dl), for both diabetes [OR:4.35 (95%CI: 2.50-7.73)] and prediabetes outcomes [OR:1.87 (95%CI 1.09-3.26)], adjusted for sex and age, smoking, body mass index, blood pressure, fasting blood glucose and insulin.

CONCLUSIONS

The risk for diabetes associated with a 1-h level >8.6mmol/l (155mg/dl) is increased and further worsened in the presence of IGT. Identifying individuals at risk with a 1-h-PG glucose level during an OGTT is recommended.

Short-term green tea extract supplementation attenuates the postprandial blood glucose and insulin response following exercise in overweight men

Green tea extract (GTE) ingestion improves glucose homeostasis in healthy and diabetic humans, but the interactive effect of GTE and exercise is unknown. The present study examined the effect of short-term GTE supplementation on the glycemic response to an oral glucose load at rest and following an acute bout of exercise, as well as substrate oxidation during exercise. Eleven sedentary, overweight men with fasting plasma glucose (FPG) ≥5.6 mmol·L^-1 (age, 34 ± 13 years; body mass index = 32 ± 5 kg·m^-2; FPG = 6.8 ± 1.0; mean ± SD) ingested GTE (3× per day, 1050 mg·day^-1 total) or placebo (PLA) for 7 days in a double-blind, crossover design. The effects of a 75-g glucose drink were assessed on 4 occasions during both GTE and PLA treatments: On days 1 and 5 at rest, and again following an acute bout of exercise on days 3 and 8. The glycemic response was assessed via an indwelling continuous glucose monitor (CGM) and venous blood draws. At rest, 1-h CGM glucose area under the curve was not different (P > 0.05), but the postexercise response was lower after GTE versus PLA (330 ± 53 and 393 ± 65 mmol·L^-1·min^-1, main effect of treatment, P < 0.05). The 1-h postprandial peaks in venous blood glucose (8.6 ± 1.6 and 9.8 ± 2.2 mmol·L^-1) and insulin (96 ± 59 and 124 ± 68 μIU·ml^-1) were also lower postexercise with GTE versus PLA (time × treatment interactions, P < 0.05). In conclusion, short-term GTE supplementation did not affect postprandial glucose at rest; however, GTE was associated with an attenuated glycemic response following a postexercise oral glucose load. These data suggest that GTE might alter skeletal muscle glucose uptake in humans.