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

Performance of the 1 h oral glucose tolerance test in predicting type 2 diabetes and association with impaired β-cell function in Asians: a national prospective cohort study

Background

Postprandial glucose concentration 1-h (1 h-PG) after an oral glucose tolerance test (OGTT) has similar or superior performance to 2 h-PG in predicting type-2 diabetes mellitus (T2DM) in several populations, and is simpler to obtain in clinical practice. However, studies in Asians are scarce. We investigated the utility of elevated baseline 1 h-PG in predicting T2DM incidence within three years, and its relationship with β-cell function in 1250 non-diabetic Asian participants.

Methods

Participants underwent an OGTT, an intravenous glucose challenge and a hyperinsulinemic-euglycemic clamp to determine glucose tolerance, acute insulin response (AIR) and insulin sensitivity at baseline. OGTTs were repeated every six months until study completion to monitor T2DM conversion.

Findings

The area under the receiver operating characteristic curve of 1 h-PG was not significantly different from 2 h-PG (AUC1h-PG = 0.883 vs. AUC2h-PG = 0.907; ΔAUC = -0.024, P = 0.124) and the optimal 1 h-PG cut-off was ≥10.7 mmol/L. When groups of high/low 1 h-PG and 2 h-PG at baseline were compared, AIR and disposition index were significantly lower in groups with high 1 h-PG, and both had a stronger correlation with 1 h-PG, indicating that impaired β-cell function was more strongly associated with elevated 1 h-PG than 2 h-PG.

Interpretation

The ability of 1 h-PG to detect Asians at risk of developing T2DM within three years is on par with 2 h-PG and the optimal cut-off is 10.7 mmol/L. Elevated 1 h-PG is associated with β-cell dysfunction. We conclude that 1 h-PG can be considered as a primary OGTT time point to identify Asians at risk for T2DM, allowing for screening at a reduced time and cost, and with lower patient burden.

Funding

National Medical Research Council (NMRC), Ministry of Health (MOH; Singapore) Industry Alignment Fund [NMRC/MOHIAFCat1/0048/2016] and Janssen Pharmaceuticals Inc. (USA).

Pathophysiological characteristics of subjects with intermediate hyperglycemia and type 2 diabetes identified by 1-hour plasma glucose during an oral glucose tolerance test

AIMS

The International Diabetes Federation (IDF) has recently recommended determination of 1-hour plasma glucose (1-hPG) during an oral glucose tolerance test (OGTT) to diagnose intermediate hyperglycemia (IH) and type 2 diabetes (T2DM). Herein, we investigated the cardiometabolic characteristics of individuals with IH and T2DM according to IDF criteria.

METHODS

We studied 3086 individuals stratified on the basis of fasting, 1-hPG and 2-hPG in four groups: 1) normal glucose tolerance (NGT), 2) isolated impaired fasting glucose (iIFG,), 3) IH (fasting glucose < 126 mg/dL, 1-hPG 155-208 mg/dL, and/or 2-hPG 140-199 mg/dL, and 4) newly diagnosed T2DM (fasting glucose, 1-hPG and/or 2-hPG≥126 mg/dL, 209 mg/dL and 200 mg/dL, respectively).

RESULTS

Individuals with IH and T2DM exhibited higher adiposity, blood pressure, uric acid, a worse lipid and inflammatory profile and a progressive reduction in Matsuda index of insulin sensitivity, insulinogenic index, and disposition index as compared to the NGT group. Moreover, individuals with IH and T2DM exhibited lower Matsuda, insulinogenic, and disposition indexes as compared to the iIFG group.

CONCLUSIONS

1-h PG-based criteria for diagnosis of IH and diabetes identify individuals having an unfavorable cardiometabolic risk profile with a progressive reduction in insulin sensitivity associated with impaired β cell function.

Implementing care for women with gestational diabetes after delivery-the challenges ahead

Gestational diabetes (GDM), defined as glucose intolerance during pregnancy, affects one in six pregnancies globally and significantly increases a woman's lifetime risk of type 2 diabetes mellitus (T2DM). Being a relatively young group, women with GDM are also at higher risk of developing diabetes related complications (e.g., cardiovascular disease, non-alcoholic fatty liver disease) later in life. Children of women with GDM are also likely to develop GDM and this perpetuates a cycle of diabetes, escalating our current pandemic of metabolic disease. The global prevalence of GDM has now risen by more than 30% over the last two decades, making it an emerging public health concern. Antepartum management of maternal glucose is unable to fully mitigate the associated lifetime cardiometabolic risk. Thus, efforts may need to focus on improving care for women with GDM during the postpartum period where prevention or therapeutic strategies could be implemented to attenuate progression of GDM to DM and its associated vascular complications. However, strategies to provide care for women in the postpartum period often showed disappointing results. This has led to a missed opportunity to halt the progression of impaired glucose tolerance/impaired fasting glucose to DM in women with GDM. In this review, we examined the challenges in the management of women with GDM after delivery and considered how each of these challenges are defined and could present as a gap in translating evidence to clinical care. We highlighted challenges related to postpartum surveillance, postpartum glucose testing strategies, postpartum risk factor modification, and problems encountered in engagement of patients/providers to implement interventions strategies in women with GDM after delivery. We reasoned that a multisystem approach is needed to address these challenges and to retard progression to DM and cardiovascular disease (CVD) in women with GDM pregnancies. This is very much needed to pave way for an improved, precise, culturally sensitive and wholistic care for women with GDM.

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.

Factors associated with maternal hyperglycaemia and neonatal hypoglycaemia after antenatal betamethasone administration in women with diabetes in pregnancy

AIMS

Bespoke glycaemic control strategies following antenatal corticosteroids for women with diabetes in pregnancy (DIP) may mitigate hyperglycaemia. This study aims to identify predictive factors for the glycaemic response to betamethasone in a large cohort of women with DIP.

METHODS

Evaluation of a prospective cohort study of 347 consecutive DIP pregnancies receiving two doses of 11.4 mg betamethasone 24 h apart between 2017 and 2021 and treated with the Pregnancy-IVI intravenous insulin protocol. Regression modelling identified factors associated with maternal glycaemic time-in-range (TIR) and maternal insulin requirements following betamethasone. Factors associated with neonatal hypoglycaemia (glucose <2.6 mmol/L) in infants born within 48 h of betamethasone administration (n = 144) were investigated.

RESULTS

The mean maternal age was 31.9 ± 5.8 years, with gestational age at betamethasone of 33.5 ± 3.4 weeks. Gestational diabetes was present in 81% (12% type 1; 7% type 2). Pre-admission subcutaneous insulin was prescribed for 63%. On-infusion maternal glucose TIR (4.0-7.8 mmol/L) was 83% [IQR 77%-90%] and mean on-IVI glucose was 6.6 ± 0.5 mmol/L. Maternal hypoglycaemia (<3.8 mmol/L) was uncommon (0.47 h/100 on-IVI woman hours). Maternal glucose TIR was negatively associated with indicators of insulin resistance (type 2 diabetes, polycystic ovary syndrome), late-pregnancy complications (pre-eclampsia, chorioamnionitis) and the 1-h OGTT result. Intravenous insulin requirements were associated with type of diabetes, pre-eclampsia and intrauterine infection, the 1-h OGTT result and the timing of betamethasone administration. Neonatal hypoglycaemia was associated with pre-existing diabetes but not with measures of glycaemic control.

CONCLUSION

An intravenous infusion protocol effectively controls maternal glucose after betamethasone. A risk-factor-based approach may allow individualisation of therapy.

Insulin Sensitivity and β-Cell Function During Early and Late Pregnancy in Women With and Without Gestational Diabetes Mellitus

OBJECTIVE

To evaluate the metabolic alterations associated with gestational diabetes mellitus (GDM) in women with overweight or obesity.

RESEARCH DESIGN AND METHODS

We compared fasting and postprandial plasma glucose and free fatty acid (FFA) concentrations, insulin sensitivity (IS; Matsuda index), and β-cell function (i.e., β-cell responsiveness to glucose) by using a frequently sampled oral glucose tolerance test (OGTT) at 15 and 35 weeks' gestation in women with overweight or obesity who had GDM (n = 29) or did not have GDM (No-GDM; n = 164) at 35 weeks.

RESULTS

At 15 weeks, IS and β-cell function were lower, and fasting, 1-h, and total area-under-the-curve plasma glucose concentrations during the OGTT were higher (all P < 0.05) in the GDM than in the No-GDM group. At 35 weeks compared with 15 weeks, IS decreased, β-cell function increased, and postprandial suppression of plasma FFA was blunted in both the GDM and No-GDM groups, but the decrease in IS and the increase in postprandial FFA concentration were greater and the increase in β-cell function was less (all P ≤ 0.05) in the GDM than in the No-GDM group. A receiver operating characteristic curve analysis showed that both fasting plasma glucose and 1-h OGTT glucose concentration at 15 weeks are predictors of GDM, but the predictive power was <30%.

CONCLUSIONS

Women with overweight or obesity and GDM, compared with those without GDM, have worse IS and β-cell function early during pregnancy and a greater subsequent decline in IS and blunted increase in β-cell function. Increased fasting and 1-h OGTT plasma glucose concentration early during pregnancy are markers of increased GDM risk, albeit with weak predictive power.

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.

From Metabolic Syndrome to Type 2 Diabetes in Youth

In the frame of metabolic syndrome, type 2 diabetes emerges along a continuum of the risk from the clustering of all its components, namely visceral obesity, high blood pressure and lipids, and impaired glucose homeostasis. Insulin resistance is the hallmark common to all the components and, in theory, is a reversible condition. Nevertheless, the load that this condition can exert on the β-cell function at the pubertal transition is such as to determine its rapid and irreversible deterioration leading to plain diabetes. The aim of this review is to highlight, in the context of metabolic syndrome, age-specific risk factors that lead to type 2 diabetes onset in youth; resume age specific screening and diagnostic criteria; and anticipate potential for treatment. Visceral obesity and altered lipid metabolism are robust grounds for the development of the disease. Genetic differences in susceptibility to hampered β-cell function in the setting of obesity and insulin resistance largely explain why some adolescents with obesity do develop diabetes at a young age and some others do not. Lifestyle intervention with a healthy diet and physical activity remains the pillar of the type 2 diabetes treatment in youth. As to the pharmacological management, metformin and insulin have failed to rescue β-cell function and to ensure long-lasting glycemic control in youth. A new era might start with the approval for use in pediatric age of drugs largely prescribed in adults, such as dipeptidyl peptidase-4 and sodium-dependent glucose transport inhibitors, and of new weight-lowering drugs in the pipeline such as single and multiple agonists of the glucagon-like peptide 1 receptor. The latter drugs can have tremendous impact on the natural history of the disease. By treating diabetes, they will reduce the burden of all the metabolic abnormalities belonging to the syndrome while causing a tremendous weight loss hitherto never seen before.

Pros and Cons of Current Diagnostic Tools for Risk-Based Screening of Prediabetes and Type 2 Diabetes in Children and Adolescents with Overweight or Obesity

It is still a matter of debate which is the most suitable diagnostic test for risk-based screening of prediabetes and type 2 diabetes (T2D) in children and adolescents with overweight or obesity. This review highlighted benefits and pitfalls of currently recommended screening tools (fasting plasma glucose [FPG], oral glucose tolerance test [OGTT], glycated hemoglobin A1c [HbA1c]). The greatest advantage of OGTT is the ability to detect people with impaired glucose tolerance, a subcategory at high risk of developing both T2D and cardiovascular disease. Important disadvantages are low reproducibility and inconvenience. FPG measurement is more practical, as it needs only one blood draw, although both OGTT and FPG require fasting. The reliability of HbA1c as a screening tool has been questioned, especially in children and adolescents, but its undeniable convenience can lead to increased adherence to screening. In contrast, it can be altered by several nonglycemic factors. Importantly, none of these tests have been validated in the pediatric population. Alternative tests have been recently proposed, including new OGTT-derived biomarkers and additional nonfasting glycemic markers. In conclusion, when choosing the most suitable test in clinical practice, advantages and disadvantages should be considered, as well as the possibility of performing different tests at once.

Predicting Factors for Metabolic Non-Response to a Complex Lifestyle Intervention-A Replication Analysis to a Randomized-Controlled Trial

BACKGROUND

T2DM heterogeneity affects responsiveness to lifestyle treatment. Beta-cell failure and nonalcoholic fatty liver disease (NAFLD) independently predict T2DM, but NAFLD inconsistently predicts metabolic response to lifestyle intervention.

AIM

We attempt to replicate a prediction model deducted from the Tübinger Lifestyle Intervention Program by assessing similar metabolic factors to predict conversion to normal glucose regulation (NGR) in a comparable lifestyle intervention trial.

METHODS

In the Optimal Fiber Trial (OptiFiT), 131 Caucasian participants with prediabetes completed a one-year lifestyle intervention program and received a fiber or placebo supplement. We compared baseline parameters for responders and non-responders, assessed correlations of major metabolic changes and conducted a logistic regression analysis for predictors of remission to NGR.

RESULTS

NGR was achieved by 33 participants, respectively. At baseline, for the placebo group only, 1 h and 2 h glucose levels, glucose AUC and Cederholm index predicted conversion to NGR. HOMA-beta, HOMA-IR or liver fat indices did not differ between responders and non-responders of the placebo or the fiber group. Changes in waist circumference or fatty liver index correlated with changes in glycemia and insulin resistance, but not with changes in insulin secretion. Insulin-resistant NAFLD did not predict non-response. Differences in compliance did not explain the results.

CONCLUSIONS

Higher post-challenge glucose levels strongly predicted the metabolic non-response to complex lifestyle intervention in our cohort. Depending on the specific intervention and the investigated cohort, fasting glucose levels and insulin sensitivity might contribute to the risk pattern. Beta-cell function did not improve in accordance with other metabolic improvements, qualifying as a potential risk factor for non-response. We could not replicate previous data suggesting that an insulin-resistant fatty liver is a specific risk factor for treatment failure. Replication studies are required.

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.

Proteomic signatures for identification of impaired glucose tolerance

The implementation of recommendations for type 2 diabetes (T2D) screening and diagnosis focuses on the measurement of glycated hemoglobin (HbA1c) and fasting glucose. This approach leaves a large number of individuals with isolated impaired glucose tolerance (iIGT), who are only detectable through oral glucose tolerance tests (OGTTs), at risk of diabetes and its severe complications. We applied machine learning to the proteomic profiles of a single fasted sample from 11,546 participants of the Fenland study to test discrimination of iIGT defined using the gold-standard OGTTs. We observed significantly improved discriminative performance by adding only three proteins (RTN4R, CBPM and GHR) to the best clinical model (AUROC = 0.80 (95% confidence interval: 0.79-0.86), P = 0.004), which we validated in an external cohort. Increased plasma levels of these candidate proteins were associated with an increased risk for future T2D in an independent cohort and were also increased in individuals genetically susceptible to impaired glucose homeostasis and T2D. Assessment of a limited number of proteins can identify individuals likely to be missed by current diagnostic strategies and at high risk of T2D and its complications.

Immuno-Mediated Inflammation in Hypertensive Patients with 1-h Post-Load Hyperglycemia

Inflammation plays a key role in the pathogenesis/progression of atherosclerosis, and inflammatory molecules contribute to the progression of cardiovascular disease. Subjects with normal post-load glucose tolerance and 1-h post-load plasma glucose >155 mg/dL have an increased risk of subclinical target organ damage and incident diabetes. We aimed to test possible differences in immune-mediated inflammatory parameters in newly-diagnosed hypertensives with or without 1-h post-load hyperglycemia. We enrolled 25 normotensives (NGT) and 50 hypertensives normotolerant on oral glucose tolerance test, further divided into two groups based on 1-h post-load plasma glucose: NGT 1-h ≥ 155 (n = 25) and NGT 1-h < 155 (n = 25). We measured toll-like receptor (TLR) 2, TLR4, nuclear factor kβ (NF-kβ), interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α. Hypertensives showed significantly worse metabolic and lipid profiles, and higher values of body mass ass index (BMI), creatinine, and inflammatory parameters, compared to controls. NGT 1-h ≥ 155 had a worse glycometabolic profile and higher values of TLR2 (9.4 ± 4.2 vs. 5.9 ± 2.6 MFI), TLR4 (13.1 ± 3.9 vs. 7.8 ± 2.3 MFI), NF-kβ (0.21 ± 0.07 vs. 0.14 ± 0.04), IL-1β (6.9 ± 3.4 vs. 3.2 ± 2.1 pg/mL), IL-6 (10.8 ± 2.6 vs. 4.1 ± 1.6 pg/mL), IL-8 (27.6 ± 9.3 vs. 13.3 ± 5.6 pg/mL), TNF-α (6.4 ± 2.9 vs. 3.3 ± 1.4 pg/mL), and high-sensitivity C-reactive protein (hs-CRP) (4.8 ± 1.5 vs. 2.7 ± 1.0 mg/dL) in comparison with NGT 1-h < 155. Matsuda-index and 1-h post-load glycemia were retained as major predictors of TLRs and NF-kβ. These results contribute to better characterizing cardiovascular risk in hypertensives.

One-hour plasma glucose level after a 75 g oral glucose load and its relationship to gastric emptying in survivors of critical illness and stress hyperglycaemia

Objective: A 1-hour plasma glucose level ≥ 8.6 mmol/L in a 75 g oral glucose tolerance test has been strongly associated with increased morbidity and mortality in outpatients without diabetes. Our primary aim was to evaluate the 1-hour plasma glucose level in a 75 g glucose tolerance test in survivors of critical illness with stress hyperglycaemia at 3 months after intensive care unit (ICU) discharge, with the secondary aims to evaluate the 2-hour plasma glucose level, glycated haemoglobin (HbA1c), and gastric emptying. Design:Post hoc analysis of a single-centre, prospective cohort study. Setting: Single-centre, tertiary referral, mixed medical-surgical ICU. Participants: Consecutively admitted patients aged ≥ 18 years who developed stress hyperglycaemia and survived to hospital discharge were eligible. Interventions: Participants returned at 3 months after ICU discharge and underwent a 75 g oral glucose tolerance test. Main outcome measures: One- and 2-hour post load plasma glucose level, HbA1c, and assessment of gastric emptying via an isotope breath test. Results: Thirty-five patients (12 females; mean age, 58.5 years [SD, 10.5]; mean HbA1c, 37.4 mmol/mol [SD, 7.0]) attended the followup. In 32/35 patients (91%) the 1-hour post load plasma glucose level was ≥ 8.6 mmol/L. There was a positive correlation between the plasma glucose level at 1 hour (r2 = 0.21; P = 0.006), but no correlation between the 2-hour glucose level (r2 = 0.006; P = 0.63) and gastric emptying. Conclusion: Glucose intolerance, when defined as 1-hour glucose level ≥ 8.6 mmol/L following a 75 g oral glucose load, persists at 3 months in most survivors of stress hyperglycaemia and is dependent on the rate of gastric emptying. Longitudinal studies to characterise mechanisms underlying dysglycaemia and progression to diabetes in individuals with stress hyperglycaemia are indicated.

Elevated One-Hour Post-Load Glucose Is Independently Associated with Albuminuria: A Cross-Sectional Population Study

The purpose of this study was to examine and compare the associations between albuminuria and fasting (FPG), 1 h post-load (1 h PG) and 2 h post-load plasma glucose (2 h PG) in an oral glucose tolerance test (OGTT). A total of 496 people free of known diabetes (mean age 72 years) participated in the examinations including the OGTT with plasma glucose measurements at 0, 1, and 2 h and levels of HbA1c. Albuminuria was determined by the urinary albumin-to-creatinine ratio and was defined as ≥3.0 mg/mmol. Compared with those without albuminuria, participants with albuminuria had significantly higher 1 h PG and 2 h PG levels, but not FPG or HbA1c levels. An elevated 1 h PG increased the estimated odds ratio of albuminuria more than three times in people with prediabetic 1 h PG (8.6–11.5 mmol/L: OR 3.60; 95% CI 1.70–7.64) and diabetic 1 h PG (≥11.6 mmol/L: OR 3.05; 95% CI 1.29–7.23). After adjusting for blood pressure and age, the association of elevated 1 h PG with albuminuria remained significant. Prediabetic or diabetic FPG, 2 h PG, or HbA1c did not have a statistically significant association with albuminuria. These findings suggest that 1 h PG seems to be the best glycemic parameter and is useful in recognizing persons with an elevated risk of early kidney disease due to hyperglycemia.

Postpartum reclassification test in gestational diabetes: can the test be reduced to 1 hour?

PURPOSE

In gestational diabetes mellitus (GDM), a postpartum oral glucose tolerance test (OGTT) is recommended. However, poor adherence to this procedure has been described, and the time required is one of the reasons. Our aims were to identify predictive factors for abnormal 2-h reclassification OGTT values, including OGTT 1-h glucose, and, if it was a factor, to determine the 1-h cutoff point that best identifies abnormal values at 2 h.

METHODS

This was a retrospective study of 769 patients diagnosed with GDM between 2014 and 2019 in a tertiary center. The sample was divided into two groups according to the presence/absence of abnormal 2-h reclassification values, and predictive factors were studied. To determine the 1-h glycemia cutoff point capable of identifying 2-h changes, a ROC curve was drawn and the Youden index was used.

RESULTS

The mean age of included women was 33.6 ± 4.95 years: 70 of them (9.1%) had an abnormal 2-h test result. Women with a history of GDM (OR = 3.41, p = .012) and higher 1-h glycemia value (OR = 1.05, p < .001) had a higher risk of developing an abnormal 2-h test result. One-hour glycemia ≥ 142 mg/dL had a sensitivity of 91.4% and specificity of 75.1% to identify changes in the test at 2 h; area under the curve to predict 2-h changes was 0.90 (CI 95%: 0.86 - 0.93).

CONCLUSION

Glucose measurement at 1 h predicts alterations at 2 h in the reclassification test with excellent diagnostic accuracy, and the cutoff point of  ≥ 142 mg/dL presents high sensitivity. These findings could serve as a foundation for a possible future redefinition of the OGTT procedure, but further investigation is required.

Lower miR-21/ROS/HNE levels associate with lower glycemia after habit-intervention: DIAPASON study 1-year later

Background

The prevalence of prediabetes is increasing in the global population and its metabolic derangements may expose to a higher risk to develop type 2 diabetes (T2D) and its cardiovascular burden. Lifestyle modifications might have considerable benefits on ameliorating metabolic status. Alternative biomarkers, such as circulating miR-21, has been recently discovered associated with dysglycemia. Here we evaluated, in a longitudinal cohort of dysglycemic population the relation between the circulating miR-21/ROS/HNE levels and the habit-intervention (HI) after 1 year of follow-up.

Methods

1506 subjects from DIAPASON study were screened based on the Findrisc score. Of them, 531 subjects with Findrisc ≥ 9 were selected for dysglycemia (ADA criteria) and tested for circulating miR-21, ROS and HNE levels, as damaging-axis. 207 subjects with dysglycemia were re-evaluated after 1-year of habit intervention (HI). Repeated measures tests were used to evaluate changes from baseline to 1-year of follow-up. The associations between glycemic parameters and miR-21/ROS/HNE were implemented by linear regression and logistic regression models.

Results

After HI, we observed a significant reduction of miR-21/ROS/HNE axis in dysglycemic subjects, concomitantly with ameliorating of metabolic parameters, including insulin resistance, BMI, microalbuminuria, reactive hyperemia index and skin fluorescence. Significant positive interaction was observed between miR-21 axis with glycaemic parameters after HI. Lower miR-21 levels after HI, strongly associated with a reduction of glycemic damaging-axis, in particular, within-subjects with values of 2hPG < 200 mg/dL.

Conclusions

Our findings demonstrated that HI influenced the epigenetic changes related to miR-21 axis, and sustain the concept of reversibility from dysglycemia. These data support the usefulness of novel biological approaches for monitoring glycemia as well as provide a screening tool for preventive programmes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01465-0.

Non-invasive Monitoring of Three Glucose Ranges Based On ECG By Using DBSCAN-CNN

Autonomic nervous system (ANS) can maintain homeostasis through the coordination of different organs including heart. The change of blood glucose (BG) level can stimulate the ANS, which will lead to the variation of Electrocardiogram (ECG). Considering that the monitoring of different BG ranges is significant for diabetes care, in this paper, an ECG-based technique was proposed to achieve non-invasive monitoring with three BG ranges: low glucose level, moderate glucose level, and high glucose level. For this purpose, multiple experiments that included fasting tests and oral glucose tolerance tests were conducted, and the ECG signals from 21 adults were recorded continuously. Furthermore, an approach of fusing density-based spatial clustering of applications with noise and convolution neural networks (DBSCAN-CNN) was presented for ECG preprocessing of outliers and classification of BG ranges based ECG. Also, ECG's important information, which was related to different BG ranges, was graphically visualized. The result showed that the percentages of accurate classification were 87.94% in low glucose level, 69.36% in moderate glucose level, and 86.39% in high glucose level. Moreover, the visualization results revealed that the highlights of ECG for the different BG ranges were different. In addition, the sensitivity of prediabetes/diabetes screening based on ECG was up to 98.48%, and the specificity was 76.75%. Therefore, we conclude that the proposed approach for BG range monitoring and prediabetes/diabetes screening has potentials in practical applications.

A study of isolated hyperglycemia (blood glucose ≥155 mg/dL) at 1-hour of oral glucose tolerance test (OGTT) in patients with β-transfusion dependent thalassemia (β-TDT) followed for 12 years

OBJECTIVE

Subjects with normal glucose tolerance (NGT) but 1-hour post-load plasma glucose (1-h OGTT) ≥ 155 mg/dl (8.6 mmol/L; H-NGT) have an increased risk for developing Type 2 diabetes mellitus (T2DM), determining a new risk factor category with deeper metabolic impairment. The aim of this study was to evaluate the H-NGT as a diagnostic predictor of future dysglycemia in β-transfusion dependent thalassemia (β-TDT). Indices of insulin secretion and insulin sensitivity derived at baseline from OGTTs, were also reviewed.

STUDY DESIGN AND METHODS

OGTT and indices of insulin secretion and insulin sensitivity, derived at baseline during OGTT, in 17 β-TDT with H-NGT and 29 β-TDT with normal OGTT (NGT) and without H-NGT followed for 12 years were studied.

RESULTS

H-NGT was associated with decreased insulin sensitivity and progressive deterioration of glucose tolerance. At baseline, serum ferritin and serum alanine aminotransferase (ALT) levels were higher in patients with H-NGT compared to patients with NGT. A strong correlation was observed between ALT and 1-hour plasma glucose value during OGTT in the total group of 36 patients . Compliance to iron chelation therapy was poor in β-TDT patients with H-NGT. An inverse correlation was found between 1-hour plasma glucose value during OGTT and insulin secretion-sensitivity index-2 (ISSI-2) (r: -0.3298; p: 0.025), between ISSI-2 and ALT (r: -0.3262; p: 0.027), and between 1-hour plasma glucose value and ISSI-2 (r: -0.537; p: 0.005) in the whole group of β-TDT patients enrolled in our study.

CONCLUSIONS

This retrospective study displayed that finding an isolated high 1-hour post-load glucose level (≥155 mg/dL; H-NGT) during the OGTT may serve as a simple biomarker to detect high-risk patients, with chronic liver disease and/or iron overload, who need periodic glycemic surveillance. Measuring the ISSI 2 represented another valuable predictive marker in the assessment of glycemia in these patients.

Depressed myocardial mechano-energetic efficiency in subjects with dysglycemia

AIMS

Evidence indicate that 1 h post-load glucose levels (1hPG) ≥ 155 mg/dl identify amongst subjects with normal glucose tolerance (NGT) a new category of prediabetes (NGT 1 h-high). A compromised myocardial mechano-energetic efficiency (MEE) is associated with type 2 diabetes and predicts adverse cardiovascular outcomes. Herein, we explored the association between prediabetes conditions such as NGT 1 h-high, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) and a decreased MEE.

METHODS

MEE was assessed by an echocardiography-derived measure in 1467 non-diabetic individuals subdivided according to their glucose tolerance: NGT and 1-hPG < 155 mg/dl (NGT 1 h-low, n = 617), NGT 1 h-high (n = 210), isolated IFG (n = 237), and IGT (n = 403).

RESULTS

Subjects with NGT 1 h-high, isolated IFG, and IGT displayed a higher myocardial oxygen consumption, and a decreased MEE in comparison to NGT 1 h-low group. MEE was inversely related to male sex, age, body mass index, total cholesterol, triglycerides, fasting and post-load glucose and insulin, C reactive protein, and positively correlated with insulin sensitivity estimated by the Matsuda index. In a stepwise multivariate linear regression model including several cardio-metabolic risk factors, 1hPG was the major predictor of MEE.

CONCLUSIONS

Subjects with NGT 1 h-high, isolated IFG, and IGT have a raised myocardial oxygen consumption and a reduced MEE.

Association of Diabetic Retinopathy With Stroke: A Systematic Review and Meta-Analysis

Background: The population-based studies conducted thus far do not provide conclusive evidence of the link between diabetic retinopathy (DR) and stroke. The aim of the present systematic review was to determine whether DR is specifically associated with stroke.

Methods: MEDLINE, Embase, and Web of Science were systematically searched from their inception to July 31, 2020. All cohort studies that reported associations between the presence of DR and incident stroke were included. The pooled hazard ratios (HRs), pooled risk ratios (RRs), and 95% confidence intervals (CIs) were calculated.

Results: The meta-analysis included 19 cohort studies involving 81,452 diabetic patients. The pooled effect size of any DR related to stroke was 1.25 for HR (95% CI: 1.12–1.39; P < 0.0001) and 1.96 for RR (95% CI: 1.60–2.39; P < 0.0001). Subgroup analysis for the type of diabetes yielded pooled HR of 1.29 (95% CI: 1.10–1.50; P = 0.001) in patients with type 2 diabetes mellitus (T2DM). The pooled RR was 2.29 (95% CI: 1.77–2.96; P < 0.0001) in patients with T2DM. Two studies addressed the DR-related stroke among type 1 diabetes mellitus (T1DM) patients. One study found a significant association between DR and stroke (OR: 1.6; 95% CI: 1.1–2.3; P < 0.01), while the other did not identify an association between these two conditions (RR: 1.40; 95% CI: 0.62–2.18; P = 0.178).

Conclusions: The presence of DR is associated with an increased risk of stroke in diabetic patients. This correlation is robust in T2DM patients but uncertain in T1DM patients. Our findings indicate that DR is an important biomarker for the prediction of stroke. To further validate the role of DR in stroke-risk stratification, additional research is required on the association between the stage of DR and stroke risk, and more studies including T1DM patients are necessary.

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.

Glucose Variability Assessed with Continuous Glucose Monitoring: Reliability, Reference Values, and Correlations with Established Glycemic Indices-The Maastricht Study

Background: Glucose variability (GV) measured by continuous glucose monitoring (CGM) has become an accepted marker of glycemic control. Nevertheless, several methodological aspects of GV assessment require further study. We, therefore, investigated the minimum number of days needed to reliably measure GV, assessed GV reference values, and studied the correlation of GV with established glycemic indices (i.e., HbA_1c, seven-point oral glucose tolerance test [OGTT]-derived indices). Methods: We used cross-sectional data from The Maastricht Study, an observational population-based cohort enriched with type 2 diabetes. Participants with more than 48 h of CGM (iPro2; Medtronic) were included for analysis (n = 851; age: 60 ± 9years; 49% women; 23% type 2 diabetes). We used mean sensor glucose (MSG), standard deviation (SD), and coefficient of variation (CV) as CGM-derived indices (the latter two for GV quantification). We calculated reliability using the Spearman-Brown prophecy formula, established reference values by calculating 2.5th-97.5th percentiles, and studied correlations using Spearman's rho. Results: Sufficient reliability (R > 0.80) was achieved with two (MSG and SD), or three monitoring days (CV). The reference ranges, assessed in individuals with normal glucose metabolism (n = 470), were 90.5-120.6 mg/dL (MSG), 7.9-24.8 mg/dL (SD), and 7.74%-22.45% (CV). For MSG, the strongest correlation was found with fasting plasma glucose (rho = 0.65 [0.61; 0.69]); for SD, with the 1-h OGTT value (rho = 0.61 [0.56; 0.65]); and for CV, with both the incremental glucose peak (IGP) during the OGTT (rho = 0.50 [0.45; 0.55]) and the 1-h OGTT value (rho = 0.50 [0.45; 0.55]). Conclusions: The reliability findings and reference values are relevant for studies that aim to investigate CGM-measured GV. One-hour OGTT and IGP values can be used as GV indices when CGM is unavailable.

A Novel Synthetic Model of the Glucose-Insulin System for Patient-Wise Inference of Physiological Parameters From Small-Size OGTT Data

Existing mathematical models for the glucose-insulin (G-I) dynamics often involve variables that are not susceptible to direct measurement. Standard clinical tests for measuring G-I levels for diagnosing potential diseases are simple and relatively cheap, but seldom give enough information to allow the identification of model parameters within the range in which they have a biological meaning, thus generating a gap between mathematical modeling and any possible physiological explanation or clinical interpretation. In the present work, we present a synthetic mathematical model to represent the G-I dynamics in an Oral Glucose Tolerance Test (OGTT), which involves for the first time for OGTT-related models, Delay Differential Equations. Our model can represent the radically different behaviors observed in a studied cohort of 407 normoglycemic patients (the largest analyzed so far in parameter fitting experiments), all masked under the current threshold-based normality criteria. We also propose a novel approach to solve the parameter fitting inverse problem, involving the clustering of different G-I profiles, a simulation-based exploration of the feasible set, and the construction of an information function which reshapes it, based on the clinical records, experimental uncertainties, and physiological criteria. This method allowed an individual-wise recognition of the parameters of our model using small size OGTT data (5 measurements) directly, without modifying the routine procedures or requiring particular clinical setups. Therefore, our methodology can be easily applied to gain parametric insights to complement the existing tools for the diagnosis of G-I dysregulations. We tested the parameter stability and sensitivity for individual subjects, and an empirical relationship between such indexes and curve shapes was spotted. Since different G-I profiles, under the light of our model, are related to different physiological mechanisms, the present method offers a tool for personally-oriented diagnosis and treatment and to better define new health criteria.

A CROSS-SECTIONAL STUDY OF THE ASSOCIATION BETWEEN THE 1-HOUR ORAL GLUCOSE TOLERANCE TEST AND THE METABOLIC SYNDROME IN A HIGH-RISK SAMPLE WITH IMPAIRED FASTING GLUCOSE

Objective: The aim of this study was to evaluate the association between the 1-hour oral glucose tolerance test (OGTT) (≥155 mg/dL) and metabolic syndrome (MS) in a sample with previous impaired fasting glucose (IFG). Methods: Three hundred and twenty four Peruvian subjects with a history of IFG ≥100 mg/dL were selected for a cross-sectional study. They underwent a 75 g OGTT and were assigned to different groups according to the result. We evaluated the association between 1-hour OGTT and MS. Results: The mean age was 56.5 ± 12.6 years and 191 (61.5%) were female. During the OGTT, we found 28 (8.6%) subjects with diabetes, 74 (22.8%) with IGT, and 222 (68.5%) with a normal glucose tolerance test with a 2-hour glucose <140 mg/dL (NGT). In the NGT group, 124 (38.3%) had 1-hour glucose levels <155 mg/dL, while 98 (30.2%) had 1-hour glucose levels ≥155 mg/dL. Evaluating the association between the 1-hour value in the OGTT and MS, we found that subjects with a 1-hour glucose ≥155 mg/dL were more than twice as likely to have MS as those with a 1-hour glucose <155 mg/dL (odds ratio = 2.64, 95% confidence interval: 1.52 to 4.57). In addition, body mass index, fasting glycemia, triglycerides, and waist circumferences were significantly higher in subjects with 1-hour glucose levels ≥155 mg/dL compared to those with 1-hour glucose levels <155 mg/dL (P<.05). Conclusion: Among subjects with IFG, performing an OGTT was helpful to identify subjects with 1-hour glucose levels ≥155 mg/dL and NGT who were significantly more likely to have MS and a worse cardiometabolic risk profile. Abbreviations: AST = aspartate aminotransferase; BMI = body mass index; CI = confidence interval; IFG = impaired fasting glucose; IGT = impaired glucose tolerance; LDL = low-density lipoprotein; MS = metabolic syndrome; NGT = normal glucose tolerance; OGTT = oral glucose tolerance test; OR = odds ratio; T2DM = type 2 diabetes; TG = triglycerides.

Elevated one hour with normal fasting and 2 h plasma glucose helps to identify those at risk for development of Type2 Diabetes-11 years observational study from south India

AIMS

To compare conversion rates of diabetes in subjects with elevated 1 h plasma glucose (1hrPG) during an OGTT with normal glucose tolerance(NGT) subjects over a period of 11 years.

METHODS

4023 subjects were selected from electronic data base of medical records.233 subjects who were followed up for a period of 11 years were included.160 with isolated prediabetes and their combinations were excluded.The remaining 73 were categorized into group1 NGT (n = 37) and group-2 (n = 36) with elevated 1hrPG.Kaplan Meier curves for incident diabetes and Cox proportional hazard model were compared between groups.

RESULTS

During follow up, 10.8% and 44.4% converted to DM in group1 and group2 (p = 0.003). Elevated 1hrPG was associated with incident diabetes(HR 7.9[95%CI 2.2-28.1](p = 0.001)provided better risk assessment.The adjusted risk of event in subjects with elevated 1hrPG is likely to be 7 times more when compared to NGT.Subjects with elevated1hrPG remained free of diabetes for a median period of 7.6 years (95% CI 5.8-7.8) whereas NGT subjects remained free for 10 years (95% CI 8.5-10.0) (p < 0.001).

CONCLUSION

In conclusion, conversion to DM was higher and risk was 7 times more in subjects with elevated 1hrPG. Elevated 1hrPG during OGTT has to be considered as a distinct entity.

Intestinal Glucose Absorption Is a Key Determinant of 1-Hour Postload Plasma Glucose Levels in Nondiabetic Subjects

CONTEXT

One-hour postload hyperglycemia, defined as 1-hour plasma glucose (1hPG) ≥ 155 mg/dL during an oral glucose tolerance test (OGTT), has been proposed as an independent predictor of type 2 diabetes. Recent evidence suggests that 1-hour hyperglycemia can be explained by enhanced duodenal glucose absorption, which in turn may increase the rate of appearance of oral glucose in the systemic circulation (RaO). However, the impact of RaO on 1hPG and 1-hour glucose excursions (incremental area under the curve calculated through the first hour after glucose ingestion; glucose iAUC1h) is still unknown.

OBJECTIVE

We quantified the relative contribution of postload RaO to 1hPG and glucose iAUC1h with respect to other major glucose homeostatic mechanisms in nondiabetic participants.

PARTICIPANTS AND METHODS

Model-derived β-cell function, insulin clearance, glucose metabolic fluxes, and peripheral and hepatic insulin sensitivity were measured during a 75-g OGTT by a double tracer method in 23 nondiabetic volunteers.

RESULTS

Early insulin secretion, whole-body insulin sensitivity, and plasma glucose disposal were significantly impaired in participants with 1hPG ≥ 155 mg/dL (n = 11), who also showed nominally greater RaO (19%; P = 0.10). In multivariable models, postload RaO showed an independent effect on both 1hPG and glucose iAUC1h (partial r2 = 0.26 and 0.48, respectively; P < 0.003). The relative contribution of RaO to 1hPG (23%) and glucose iAUC1h (30%) was similar to that of early insulin secretion and peripheral insulin sensitivity and greater than that of hepatic insulin sensitivity.

CONCLUSIONS

Our data highlight the primary role of RaO as a major determinant of 1-hour postprandial glucose excursions in nondiabetic participants.

One-hour post-load plasma glucose predicts progression to prediabetes in a multi-ethnic cohort of obese youths

AIMS

One-hour post-load hyperglycaemia has been proposed as an independent predictor of type 2 diabetes in adults. We examined whether 1-hour plasma glucose (1hPG) during an oral glucose tolerance test (OGTT) can predict changes in the glucose tolerance status of a multi-ethnic cohort of youths with normal glucose tolerance (NGT).

MATERIALS AND METHODS

A total of 202 obese youths with NGT (33.7% Caucasian, 31.1% Hispanic, 32.2% African American) underwent a 3-hour OGTT at baseline and after a 2-year follow-up period. Whole-body insulin sensitivity, insulin secretion, β-cell function and insulin clearance were estimated by modeling plasma glucose, insulin and C-peptide levels.

RESULTS

Obese youths with 1hPG ≥7.4 mmol/L (or 133 mg/dL; n = 83) exhibited higher body mass index (BMI), plasma triglycerides and fasting and post-load glucose concentrations than individuals with 1hPG <7.4 mmol/L. Also, 1hPG ≥7.4 mmol/L was associated with a lower disposition index (DI) (P < 0.0001) and with alterations in whole-body insulin sensitivity, β-cell function and insulin clearance. Adolescents with 1hPG ≥7.4 mmol/L were approximately three times more likely to develop prediabetes (ie, impaired glucose tolerance and/or impaired fasting glucose) over time (OR, 2.92 [1.22-6.98]; P = 0.02), independent of age, sex, race/ethnicity, BMI, insulin sensitivity, DI and plasma glucose concentrations. No differences emerged in the risk of prediabetes related to 1-hour hyperglycaemia among different ethnic groups.

CONCLUSIONS

A plasma glucose concentration ≥ 7.4 mmol/L at 1 hour during an OGTT is associated with a worse clinical and metabolic phenotype and may be an independent predictor of progression to prediabetes in obese youths with NGT.

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.

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.