Modelling of OGTT curve identifies 1 h plasma glucose level as a strong predictor of incident type 2 diabetes: results from two prospective cohorts

One-hour post-load plasma glucose level predicts future type 2 diabetes in a community-based study of Hong Kong Chinese workforce

BACKGROUND

We compared performance of high 1-hour PG level, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) in predicting type 2 diabetes in a longitudinal community-based cohort of Hong Kong Chinese.

METHODS

Between 2001 and 2003, 472 adults aged 18-55 years without diabetes underwent 75-gram oral glucose tolerance test (OGTT). Between 2012 and 2014, progression to diabetes was ascertained by reviewing medical records or repeating OGTT and HbA1c. We defined high 1-hour PG as PG ≥ 8.6 mmol/L at 1-hour.

RESULTS

In this cohort, 23.5% had normal glucose tolerance and high 1-hour PG, 10.0% had isolated IGT, 4.2% had isolated IFG. Over 12-year follow-up, 9.3% developed type 2 diabetes. In logistic regression, high 1-hour PG was associated with progression to type 2 diabetes with adjusted odds ratio (95% CI) of 4.20 (1.60, 12.40), independent of IFG, IGT and other clinical variables. Areas under ROC (95% CI) for type 2 diabetes were similar between 1-hour (0.84 [0.78, 0.89], 2-hour (0.79 [0.72, 0.86]) and fasting PG (0.79 [0.71, 0.86]).

CONCLUSION

High 1-hour PG identified young Chinese with 5-fold increased risk of type 2 diabetes independent of other intermediate hyperglycaemia status and clinical factors. 1-hour PG is similar to fasting and 2-hour PG in predicting type 2 diabetes.

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.

One-hour post-load glucose levels are associated with hepatic steatosis assessed by transient elastography

AIM

To examine the association between 1-hour plasma glucose (PG) concentration and markers of non-alcoholic fatty liver disease (NAFLD) assessed by transient elastography (TE).

METHODS

We performed TE in 107 metabolically well-characterized non-diabetic White individuals. Controlled attenuation parameter (CAP) was used to quantify liver steatosis, while liver stiffness marker (LS) was used to evaluate fibrosis.

RESULTS

Controlled attenuation parameter correlated significantly with 1-hour PG (r = 0.301, P < 0.01), fasting insulin (r = 0.285, P < 0.01), 2-hour insulin (r = 0.257, P < 0.02), homeostasis model assessment index of insulin resistance (r = 0.252, P < 0.01), high-density lipoprotein cholesterol (r = -0.252, P < 0.02), body mass index (BMI; r = 0.248, P < 0.02) and age (r = 0.212, P < 0.03), after correction for age, sex and BMI. In a multivariable linear regression analysis, 1-hour PG (β = 0.274, P = 0.008) and fasting insulin levels (β = 0.225, P = 0.029) were found to be independent predictors of CAP. After excluding subjects with prediabetes, 1-hour PG was the sole predictor of CAP variation (β = 0.442, P < 0.001). In a logistic regression model, we observed that the group with 1-hour PG ≥  8.6 mmol/L (155 mg/dL) had a significantly higher risk of steatosis (odds ratio 3.98, 95% confidence interval 1.43-11.13; P = 0.008) than individuals with 1-hour PG <  8.6 mmol/L, after correction for potential confounders. No association was observed between 1-hour PG and LS.

CONCLUSION

Our data confirm that 1-hour PG ≥  8.6 mmol/L is associated with higher signs of NAFLD, even among individuals with normal glucose tolerance, categorized as low risk by canonical diagnostic standards. TE is a safe low-impact approach that could be employed for stratifying the risk profile in these patients, with a high level of accuracy.

Is glucose pattern of OGTT associated with late-onset gestational diabetes and adverse pregnant outcomes?

BACKGROUND

The heterogeneity of oral glucose tolerance test (OGTT) patterns during pregnancy remains unclear. This study aims to identify latent OGTT patterns in pregnant women and investigate the high-risk population for late-onset gestational diabetes mellitus (GDM).

METHODS

This study including 17,723 participants was conducted from 2018 to 2021. Latent mixture modeling was used to identify subgroups. Modified Poisson regression was performed to explore the relationship between OGTT patterns and late-onset GDM or adverse perinatal outcomes.

RESULTS

Three distinct glucose patterns, high, medium, and low glucose levels (HG, MG, and LG patterns) were identified. The HG pattern represented 28.5% of the participants and 5.5% of them developed late-onset GDM. A five-fold higher risk of late-onset GDM was found in HG pattern than in LG pattern (relative risk [RR]: 5.17, 95% confidence interval [CI]: 3.38-7.92) after adjustment. Participants in HG pattern were more likely to have macrosomia, large for gestational age, preterm birth, and cesarean deliveries, with RRs of 1.59 (1.31-1.93), 1.55 (1.33-1.82), 1.30 (1.02-1.64) and 1.15 (1.08-1.23), respectively.

CONCLUSION

Three distinct OGTT patterns presented different risks of late-onset GDM and adverse perinatal outcomes, indicating that timely monitoring of glucose levels after OGTT should be performed in pregnant women with HG pattern.

Poplar Propolis Improves Insulin Homeostasis in Non-Diabetic Insulin-Resistant Volunteers with Obesity: A Crossover Randomized Controlled Trial

Propolis, a natural resinous mixture rich in polyphenols, produced by bees from a variety of plant sources, has shown significant therapeutic effects and may prevent the development of certain chronic diseases like type 2 diabetes mellitus (T2DM). The objective of this study was to evaluate the effect of supplementation with standardized poplar propolis extract powder (PPEP) on insulin homeostasis in non-diabetic insulin-resistant volunteers with obesity. In this randomized, controlled, crossover trial, nine non-diabetic insulin-resistant volunteers with obesity, aged 49 ± 7 years, were subjected to two periods of supplementation (placebo and PPEP) for 3 months. Blood samples and anthropomorphic data were collected at baseline and at the end of each phase of the intervention. PPEP supplementation improved insulin sensitivity by significantly decreasing the percentage of insulin-resistant subjects and the insulin sensitivity Matsuda index (ISI-M). According to this study, supplementation with standardized PPEP for 3 months in non-diabetic insulin-resistant volunteers with obesity led to an improvement in insulin homeostasis by its effect on insulin resistance and secretion. This study suggests that poplar propolis has a preventive effect on the physiopathological mechanisms of T2DM and, therefore, that it can help to prevent the development of the disease.

The role of TyG index in predicting the incidence of diabetes in Chinese elderly men: a 20-year retrospective study

Background

The triglyceride glucose index (TyG index) has been regarded as a reliable surrogate marker of insulin resistance and an independent predictor of diabetes. However, few studies have reported the association between the TyG index and diabetes in the elderly population. Accordingly, this study aimed to investigate the association between the TyG index and diabetes progression in elderly Chinese.

Methods

Baseline medical history, fasting plasma glucose (FPG), glucose levels during the oral glucose tolerance test (OGTT) after 1-hour (1h-PG) and 2-hour (2h-PG), and triglyceride (TG) were obtained from a cohort of 862 elderly (aged ≥ 60 years) Chinese in the Beijing urban area between 1998 and 1999. A follow-up visit was conducted between 1998 and 2019 to assess incident diabetes. TyG index was calculated by the following formula ln[TG (mg/dL) × FPG (mg(dL)/2]. The predictive values of TyG index, lipids, and glucose levels during OGTT were assessed alone and also in a clinical prediction model comprising traditional risk factors using concordance index (C-index). Areas under the receiver operating characteristics curves (AUC) and 95% CIs were calculated.

Results

After 20 years of follow-up, there were 544 cases of incident type 2 diabetes mellitus (63.1% of incidence). The multivariable HRs (95% CI) for TyG index, FPG, 1h-PG and 2h-PG, high-density lipoprotein-cholesterol (HDL-c), and TG were 1.525 (1.290-1.804), 1.350 (1.181-1.544), 1.337 (1.282-1.395), 1.401 (1.327-1.480), 0.505 (0.375-0.681), and 1.120 (1.053-1.192), respectively. The corresponding C-index were 0.623, 0.617, 0.704, 0.694, 0.631, and 0.610, respectively. The AUC (95% CI) for the TyG index, FPG, 1h-PG, 2h-PG, HDL-c, and TG were 0.608 (0.569-0.647), 0.587 (0.548-0.625), 0.766 (0.734-0.797), 0.713 (0.679-0.747), 0.397 (0.358-0.435), and 0.588 (0.549-0.628). The AUC of the TyG index was higher than that of TG but did not differ with FPG and HDL-c. In addition, the AUCs of 1h-PG and 2h-PG were higher than that of the TyG index.

Conclusions

Elevated TyG index is independently correlated with an increased risk of incident diabetes in the elderly male population, but it is not superior to OGTT 1h-PG and 2h-PG in predicting the risk of diabetes.

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.

A simulation model estimates lifetime health and economic outcomes of screening prediabetes using the 1-h plasma glucose

AIMS

The current method to diagnose impaired glucose tolerance (IGT) is based on the 2-h plasma glucose (2-hPG) value during a 75-g oral glucose tolerance test (OGTT). Robust evidence demonstrates that the 1-h post-load plasma glucose (1-hPG) ≥ 8.6 mmol/L in those with normal glucose tolerance is highly predictive of type 2 diabetes (T2D), micro and macrovascular complications and mortality. The aim of this study was to conduct a health economic analysis to estimate long-term cost-effectiveness of using the 1-hPG compared to the 2-hPG for screening and assessing the risk of diabetes over 35 years. The main outcome was cost per quality-adjusted life year (QALY) gained.

METHODS

A Monte Carlo-based Markov simulation model was developed to forecast long-term effects of two screening strategies with regards to clinical and cost-effectiveness outcomes. The base case model included 20,000 simulated patients over 35-years follow-up. Transition probabilities on disease progression, mortality, effects on preventive treatments and complications were retrieved from landmark diabetes studies. Direct medical costs were sourced from published literature and inflated to 2019 Euros.

RESULTS

In the lifetime analysis, the 1-hPG was projected to increase the number of years free from disease (2 years per patient); to delay the onset of T2D (1 year per patient); to reduce the incidence of T2D complications (0·6 RR-Relative Risk per patient) and to increase the QALY gained (0·58 per patient). Even if the 1-hPG diagnostic method resulted in higher initial costs associated with preventive treatment, long-term diabetes-related costs as well as complications costs were reduced leading to a lifetime saving of - 31225719.82€. The incremental cost-effectiveness ratio was - 8214.7€ per each QALY gained for the overall population.

CONCLUSIONS

Screening prediabetes with the 1-hPG is feasible and cost-effective resulting in reduced costs per QALY. Notwithstanding, the higher initial costs of testing with the 1-hPG compared to the 2-hPG due to incremental preventive intervention, long-term diabetes and complications costs were reduced projecting an overall cost saving of - 8214.7€ per each QALY gained.

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.

No Indices of Increased Type 2 Diabetes Risk in Individuals with Reactive Postprandial Hypoglycemia

Reactive postprandial hypoglycemia (RPH) is an understudied condition that lacks clinical definition, knowledge of future health implications, and an understanding of precise underlying mechanisms. Therefore, our study aimed to assess the glycemic response after glucose ingestion in individuals several years after the initial evaluation of RPH and to compare glucose regulation in individuals with RPH vs. healthy volunteers. We assessed the inter- and intra-individual differences in glucose, insulin, and C-peptide concentrations during 5-h oral glucose tolerance tests (OGTTs); the surrogate markers of insulin resistance (HOMA-IR and Matsuda index); and beta-cell function (distribution index and insulinogenic index). The study included 29 subjects with RPH (all females, aged 39 (28, 46) years) and 11 sex-, age-, and body mass index (BMI)-matched controls. No biochemical deterioration of beta-cell secretory capacity and no progression to dysglycemia after 6.4 ± 4.2 years of follow-up were detected. RPH subjects were not insulin resistant, and their insulin sensitivity did not deteriorate. RPH subjects exhibited no differences in concentrations or in the shape of the glucose-insulin curves during the 5-h OGTTs compared to age- and BMI-matched controls. No increased incident type 2 diabetes risk indices were evident in individuals with RPH. This dictates the need for further research to investigate the magnitude of future diabetes risk in individuals experiencing RPH.

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.

The characteristics of postprandial glycemic response patterns to white rice and glucose in healthy adults: Identifying subgroups by clustering analysis

OBJECTIVES

Large interpersonal variability in postprandial glycemic response (PGR) to white rice has been reported, and differences in the PGR patterns during the oral glucose tolerance test (OGTT) have been documented. However, there is scant study on the PGR patterns of white rice. We examined the typical PGR patterns of white rice and glucose and the association between them.

MATERIALS AND METHODS

We analyzed the data of 3-h PGRs to white rice (WR) and glucose (G) of 114 normoglycemic female subjects of similar age, weight status, and same ethnic group. Diverse glycemic parameters, based on the discrete blood glucose values, were calculated over 120 and 180 min. K-means clustering based on glycemic parameters calculated over 180 min was applied to identify subgroups and representative PGR patterns. Principal factor analysis based on the parameters used in the cluster analysis was applied to characterize PGR patterns. Simple correspondence analysis was performed on the clustering categories of WR and G.

RESULTS

More distinct differences were found in glycemic parameters calculated over 180 min compared with that calculated over 120 min, especially in the negative area under the curve and Nadir. We identified four distinct PGR patterns to WR (WR1, WR2, WR3, and WR4) and G (G1, G2, G3, and G4), respectively. There were significant differences among the patterns regard to postprandial hyperglycemia, hypoglycemic, and glycemic variability. The WR1 clusters had significantly lower glycemic index (59 ± 19), while no difference was found among the glycemic index based on the other three clusters. Each given G subgroup presented multiple patterns of PGR to WR, especially in the largest G subgroup (G1), and in subgroup with the greatest glycemic variability (G3).

CONCLUSION

Multiple subgroups could be classified based on the PGR patterns to white rice and glucose even in seemingly homogeneous subjects. Extending the monitoring time to 180 min was conducive to more effective discrimination of PGR patterns. It may not be reliable to extrapolate the patterns of PGR to rice from that to glucose, suggesting a need of combining OGTT and meal tolerance test for individualized glycemic management.

EVALUATION OF HIGH LEVELS OF SPORTS ACTIVITY AND THE BENEFICIAL EFFECT ON POSTPRANDIAL BLOOD GLUCOSE PROFILES

ABSTRACT Introduction: Hyperglycemia is the principal characteristic component of type 2 diabetes. High blood glucose concentrations for long periods can be countered with postprandial exercise by increasing glucose retention involuntary muscles. However, no research is present on the relationship between exercise time and glucose levels. Objective: This study evaluates the relationship between sports activity and postprandial glycemia levels. Methodology: Forty-five individuals were included in the study, 10 males and 35 females with an age of 27.11±2.8 years; a body fat percentage of 25.02% ±5.04%; and a body mass index of 22.74±4.55 kg/m2. Participants were included via WhatsApp for daily information on postprandial activity levels. WhatsApp messages were forwarded to a total of 2,500 people at different colleges and universities. Out of the total 60 active people (2.40%) who responded, 45 individuals participated in the study. They were divided into three categories based on self-reported postprandial activity: not very active (15), quite active (15), highly active (15). All active individuals completed an oral glucose intake test with blood samples obtained for evaluation at 15, 30, 45, 60, 90, and 120 minutes post-rest. On a gender basis, the groups could not be associated (P =.057). Results: All active groups showed a remarkable effect on blood glucose level at one hour (P =.031). A mean increase in blood glucose level in the first hour of 1.50 mmol/L was observed for every extra 1.0 mmol/L of standard glycemic amount, on average, women had a higher blood glucose amount of 1.35 mmol/L than men. Conclusion: It can be concluded that a high amount of postprandial activity generates a good outcome on glycemic parameters. Evidence Level II; Therapeutic Studies – Investigating the results.

Mechanistic Insights Into the Heterogeneity of Glucose Response Classes in Youths With Obesity: A Latent Class Trajectory Approach

OBJECTIVE

In a large, multiethnic cohort of youths with obesity, we analyzed pathophysiological and genetic mechanisms underlying variations in plasma glucose responses to a 180 min oral glucose tolerance test (OGTT).

RESEARCH DESIGN AND METHODS

Latent class trajectory analysis was used to identify various glucose response profiles to a nine-point OGTT in 2,378 participants in the Yale Pathogenesis of Youth-Onset T2D study, of whom 1,190 had available TCF7L2 genotyping and 358 had multiple OGTTs over a 5 year follow-up. Insulin sensitivity, clearance, and β-cell function were estimated by glucose, insulin, and C-peptide modeling.

RESULTS

Four latent classes (1 to 4) were identified based on increasing areas under the curve for glucose. Participants in class 3 and 4 had the worst metabolic and genetic risk profiles, featuring impaired insulin sensitivity, clearance, and β-cell function. Model-predicted probability to be classified as class 1 and 4 increased across ages, while insulin sensitivity and clearance showed transient reductions and β-cell function progressively declined. Insulin sensitivity was the strongest determinant of class assignment at enrollment and of the longitudinal change from class 1 and 2 to higher classes. Transitions between classes 3 and 4 were explained only by changes in β-cell glucose sensitivity.

CONCLUSIONS

We identified four glucose response classes in youths with obesity with different genetic risk profiles and progressive impairment in insulin kinetics and action. Insulin sensitivity was the main determinant in the transition between lower and higher glucose classes across ages. In contrast, transitions between the two worst glucose classes were driven only by β-cell glucose sensitivity.

Oral glucose tolerance testing at 1 h and 2 h: relationship with glucose and cardiometabolic parameters and agreement for pre-diabetes diagnosis in patients with morbid obesity

BACKGROUND

One hour plasma glucose concentration (1hPG) during an oral glucose tolerance test (OGTT) may be an alternative to 2-h plasma glucose concentration (2hPG) in the identification of individuals at increased risk of hyperglycaemia, although its role is not fully understood.

AIM

We aim to investigate the relationship of these measures with other glucose parameters, as well as their relationship with cardiometabolic risk markers and the level of agreement for prediabetes mellitus diagnosis, in a sample of patients with morbid obesity.

METHODS

We retrospectively evaluated 656 patients with morbid obesity without diagnosed diabetes. To define prediabetes with 2hPG, 2022 American Diabetes Association guidelines criteria were used, while for 1hPG, glucose ≥ 155 mg/dL was considered. Cohen's Kappa coefficient was used to assess the agreement between both measures of prediabetes mellitus diagnosis.

RESULTS

A Cohen's Kappa coefficient of 0.405 (p < 0.001) was obtained. The 1hPG were positively correlated with homeostatic model assessment for insulin resistance (HOMA-IR) (ρ = 0.281, p < 0.001), fasting plasma glucose (FPG) (ρ = 0.581, p < 0.001), glycated haemoglobin (Hb1AC) (ρ = 0.347, p < 0.001) and were negatively correlated with homeostatic model assessment for cell-β function (HOMA-β) (ρ = -0.092, p = 0.018). 2hPG were also correlated with the same parameters, except for HOMA-β.

CONCLUSION

A fair agreement between 1 and 2hPG was verified. 1hPG criteria may be a useful indicator of β-cell dysfunction and insulin resistance in patients with morbid obesity without diabetes diagnosis.

The bad rainbow of COVID-19 time: effects on glucose metabolism in children and adolescents with obesity and overweight

Background

COVID-19 restriction measurements have enhanced the obesity status in the pediatric population which might further contribute to obesity-related glucose-insulin metabolism alterations. Therefore, we retrospectively compared anthropometric and OGTT data on children with obesity during the 13 years before and during the COVID-19 pandemic.

Subjects/methods

Data from 741 children with obesity and overweight were retrieved and clustered into seven groups starting from year 2008–2009 until 2020–2021. Differences in anthropometric measurements and glucose/insulin metabolism were evaluated between the different groups.

Results

Children with overweight and obesity in the COVID-19 restriction group did not present increased values of SDS­Body Mass Index (BMI). Significantly higher values for Waist Circumference (WC), SDS-WC, Waist/Height ratio (WHtR), and body mass fat were detected in these children (all P < 0.01). Fasting glycaemia, glucose, and insulin excursions were significantly higher compared to pre­ pandemic children (all P < 0.01). Insulin resistance was higher while insulin secretion was lower (all P < 0.01) determining a significantly higher percentage of impaired glucose tolerance in the COVID-19 restriction group (P < 0.002). Furthermore, High-Density Lipoprotein (HDL) cholesterol was significantly lower (P < 0.01) and SDS for systolic and diastolic blood pressure values were significantly higher (P = 0.03 and P = 0.02, respectively).

Conclusions

COVID-19 restriction measurements determined profound alterations in glucose and insulin metabolism in children with obesity and overweight. Urgent strategies are needed in order to reverse COVID-19 restriction measures’ effects on glucose and insulin metabolism.

Associations of the HOMA2-%B and HOMA2-IR with progression to diabetes and glycaemic deterioration in young and middle-aged Chinese

AIMS

Insulin deficiency (ID) and resistance (IR) contribute to progression from normal glucose tolerance to diabetes to insulin requirement although their relative contributions in young-onset diabetes is unknown.

METHODS

We examined the associations of HOMA2 using fasting plasma glucose and C-peptide in Chinese aged 20-50 years with (1) progression to type 2 diabetes (T2D) in participants without diabetes in a community-based cohort (1998-2013) and (2) glycaemic deterioration in patients with T2D in a clinic-based cohort (1995-2014). We defined ID as HOMA2-%B below median and insulin IR as HOMA2-IR above median.

RESULTS

During 10-year follow-up, 62 (17.9%) of 347 community-dwelling participants progressed to T2D. After 8.6 years, 291 (48.1%) of 609 patients with T2D had glycaemic deterioration. At baseline, progressors for T2D had higher HOMA2-IR, while in patients with T2D, progressors for glycaemic deterioration had higher HOMA2-IR and lower HOMA2-%B than non-progressors. The non-ID/IR group and the ID/IR group had an adjusted odds ratios of 2.47 (95% CI: 1.28, 4.94) and 5.36 (2.26, 12.79), respectively, for incident T2D versus the ID/non-IR group. In patients with T2D, 50% of the ID/IR group required insulin at 6.7 years versus around 11 years in the non-ID/IR or ID/non-IR, and more than 15 years in the non-ID/non-IR group. Compared with the latter group, the adjusted hazard ratios were 2.74 (1.80, 4.16) in the ID/non-IR, 2.73 (1.78, 4.19) in the non-ID/IR and 4.46 (2.87, 6.91) in the ID/IR group (p-interaction = 0.049).

CONCLUSIONS

In young Chinese adults, IR and ID contributed to progression to T2D and glycaemic deterioration.

Oral glucose tolerance test in diabetes, the old method revisited

The oral glucose tolerance test (OGTT) has been widely used both in clinics and in basic research for a long time. It is applied to diagnose impaired glucose tolerance and/or type 2 diabetes mellitus in individuals. Additionally, it has been employed in research to investigate glucose utilization and insulin sensitivity in animals. The main aim of each was quite different, and the details are also somewhat varied. However, the time or duration of the OGTT was the same, using the 2-h post-glucose load glycemia in both, following the suggestions of the American Diabetes Association. Recently, the use of 30-min or 1-h post-glucose load glycemia in clinical practice has been recommended by several studies. In this review article, we describe this new view and suggest perspectives for the OGTT. Additionally, quantification of the glucose curve in basic research is also discussed. Unlike in clinical practice, the incremental area under the curve is not suitable for use in the studies involving animals receiving repeated treatments or chronic treatment. We discuss the potential mechanisms in detail. Moreover, variations between bench and bedside in the application of the OGTT are introduced. Finally, the newly identified method for the OGTT must achieve a recommendation from the American Diabetes Association or another official unit soon. In conclusion, we summarize the recent reports regarding the OGTT and add some of our own perspectives, including machine learning and others.

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 mean of fasting, 1-h, and 2-h plasma glucose levels is superior to each separate index in predicting diabetes

AIMS

The fasting, 1-h, and 2-h plasma glucose (PG) levels during oral glucose tolerance test represent different glucose metabolic functions. We examined whether averaging these PG indices (GLU_M0.60.120) results in a better predictor of future type 2 diabetes (T2DM).

METHODS

7533 participants were followed up biannually for 12 years. Hazard ratios (HRs), area under the curve (AUC) of the receiver-operating characteristic, and the net reclassification index (NRI) for T2DM were calculated to compare the discriminative ability of GLU_M0.60.120 versus other PG indices.

RESULTS

The adjusted HRs and 95% confidence intervals for an increase in SD of GLU_M0.60.120 was 2.50 (2.36-2.65) and 1.88 (1.73-2.04) in T2DM-free and normal glucose tolerance (NGT) participants, respectively. The AUC of GLU_M0.60.120 was higher than that of fasting PG, 1-h, and 2-h PG values for T2DM-free (0.79 versus 0.67, 0.77, and 0.73) and NGT (0.73 versus 0.65, 0.72, and 0.61). The model using GLU_M0.60.120 improved the classification of the models with fasting PG, 1-h, and 2-h PG values (NRI: 0.369, 0.272, and 0.282 for T2DM-free and 0.249, 0.131, and 0.351 for NGT participants with all p < 0.001).

CONCLUSIONS

The mean of fasting, 1-h, and 2-h PG levels predicts future T2DM better than each index.

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

AIM

To examine the hypothesis that, based on their glucose curves during a seven-point oral glucose tolerance test, people at elevated type 2 diabetes risk can be divided into subgroups with different clinical profiles at baseline and different degrees of subsequent glycaemic deterioration.

METHODS

We included 2126 participants at elevated type 2 diabetes risk from the Diabetes Research on Patient Stratification (IMI-DIRECT) study. Latent class trajectory analysis was used to identify subgroups from a seven-point oral glucose tolerance test at baseline and follow-up. Linear models quantified the associations between the subgroups with glycaemic traits at baseline and 18 months.

RESULTS

At baseline, we identified four glucose curve subgroups, labelled in order of increasing peak levels as 1-4. Participants in Subgroups 2-4, were more likely to have higher insulin resistance (homeostatic model assessment) and a lower Matsuda index, than those in Subgroup 1. Overall, participants in Subgroups 3 and 4, had higher glycaemic trait values, with the exception of the Matsuda and insulinogenic indices. At 18 months, change in homeostatic model assessment of insulin resistance was higher in Subgroup 4 (β = 0.36, 95% CI 0.13-0.58), Subgroup 3 (β = 0.30; 95% CI 0.10-0.50) and Subgroup 2 (β = 0.18; 95% CI 0.04-0.32), compared to Subgroup 1. The same was observed for C-peptide and insulin. Five subgroups were identified at follow-up, and the majority of participants remained in the same subgroup or progressed to higher peak subgroups after 18 months.

CONCLUSIONS

Using data from a frequently sampled oral glucose tolerance test, glucose curve patterns associated with different clinical characteristics and different rates of subsequent glycaemic deterioration can be identified.

Hyperglycemia at 1h-OGTT in Pregnancy: A Reliable Predictor of Metabolic Outcomes?

Gestational diabetes mellitus (GDM) is associated with a high risk of developing type 2 diabetes (T2DM) and cardiovascular disease (CVD). Identifying among GDM women those who are at high risk may help prevent T2DM and, possibly CVD. Several studies have shown that in women with GDM, hyperglycemia at 1 h during an oral glucose tolerance test (OGTT) (1-h PG) is not only associated with an increase in adverse maternal and perinatal outcomes but is also an independent predictor of T2DM. Interestingly, also in pregnant women who did not meet the criteria for a GDM diagnosis, 1-h PG was an independent predictor of postpartum impaired insulin sensitivity and beta-cell dysfunction. Moreover, maternal 1- and 2-h PG levels have been found to be independently associated with insulin resistance and impaired insulin secretion also during childhood. There is evidence that hyperglycemia at 1h PG during pregnancy may identify women at high risk of future CVD, due to its association with an unfavorable CV risk profile, inflammation, arterial stiffness and endothelial dysfunction. Overall, hyperglycemia at 1h during an OGTT in pregnancy may be a valuable prediction tool for identifying women at a high risk of future T2DM, who may then benefit from therapeutic strategies aimed at preventing cardiovascular outcomes.

No deleterious effect of an additional pregnancy on glucose metabolism in women with previous gestational diabetes mellitus

OBJECTIVE

Women with gestational diabetes mellitus (GDM) often develop type 2 diabetes later in life. It remains unclear whether this results solely from a common underlying predisposition or, whether a pregnancy itself persistently impairs glucose metabolism in predisposed women. We therefore examined how an additional pregnancy affected different aspects of glucose metabolism in women with previous GDM.

RESEARCH DESIGN AND METHODS

Nested case-control study within the prospective cohort study PPSDiab, recruited in Munich, Germany from 2011-16. Cases (n = 41): women with previous GDM who completed an additional pregnancy; controls: no additional pregnancy, pairwise matching.

ENDPOINTS

change of the area under the glucose curve (AUGC) of an oral glucose tolerance, of plasma glucose at 60' of the test (PG 60'), of the insulin sensitivity index (ISI) and of the disposition index (DI), all between before and after the additional pregnancy in cases/the corresponding observation period in controls.

RESULTS

We observed no significant difference between cases and controls in the primary [ratio AUGC 1.05(0.92-1.15) vs. 0.97(0.85-1.14); p = 0.21] and in the secondary endpoints [difference PG 60', ratio ISI and ratio DI.

CONCLUSION

We did not find a deleterious effect of an additional pregnancy on glucose metabolism in women with previous GDM.

Post-load glucose subgroups and associated metabolic traits in individuals with type 2 diabetes: An IMI-DIRECT study

Aim

Subclasses of different glycaemic disturbances could explain the variation in characteristics of individuals with type 2 diabetes (T2D). We aimed to examine the association between subgroups based on their glucose curves during a five-point mixed-meal tolerance test (MMT) and metabolic traits at baseline and glycaemic deterioration in individuals with T2D.

Methods

The study included 787 individuals with newly diagnosed T2D from the Diabetes Research on Patient Stratification (IMI-DIRECT) Study. Latent class trajectory analysis (LCTA) was used to identify distinct glucose curve subgroups during a five-point MMT. Using general linear models, these subgroups were associated with metabolic traits at baseline and after 18 months of follow up, adjusted for potential confounders.

Results

At baseline, we identified three glucose curve subgroups, labelled in order of increasing glucose peak levels as subgroup 1–3. Individuals in subgroup 2 and 3 were more likely to have higher levels of HbA1c, triglycerides and BMI at baseline, compared to those in subgroup 1. At 18 months (n = 651), the beta coefficients (95% CI) for change in HbA1c (mmol/mol) increased across subgroups with 0.37 (-0.18–1.92) for subgroup 2 and 1.88 (-0.08–3.85) for subgroup 3, relative to subgroup 1. The same trend was observed for change in levels of triglycerides and fasting glucose.

Conclusions

Different glycaemic profiles with different metabolic traits and different degrees of subsequent glycaemic deterioration can be identified using data from a frequently sampled mixed-meal tolerance test in individuals with T2D. Subgroups with the highest peaks had greater metabolic risk.

Responses to oral glucose challenge differ by physical activity volume and intensity: A pilot study

BACKGROUND

One-hour postprandial hyperglycemia is associated with increased risk of type 2 diabetes and cardiovascular disease. Physical activity (PA) has short-term beneficial effects on post-meal glucose response. This study compared the oral glucose tolerance test results of 3 groups of people with habitually different levels of PA.

METHODS

Thirty-one adults without diabetes (age 25.9 ± 6.6 years; body mass index 23.8 ± 3.8 kg/m²; mean ± SD) were recruited and divided into 3 groups based on self-reported PA volume and intensity: low activity < 30 min/day of moderate-intensity activity (n = 11), moderately active ≥ 30 min/day of moderate-intensity PA (n = 10), and very active ≥ 60 min/day of PA at high intensity (n = 10). Participants completed an oral glucose tolerance test (50 g glucose) with capillary blood samples obtained at baseline, 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min post-ingestion.

RESULTS

There were no significant differences between groups for age or body fat percentage or glycated hemoglobin (p > 0.05). The groups were significantly different in terms of baseline glucose level (p = 0.003) and, marginally, for gender (p = 0.053) and BMI (p = 0.050). There was a statistically significant effect of PA on the 1-h postprandial glucose results (p = 0.029), with differences between very active and low activity groups (p = 0.008) but not between the moderately active and low activity groups (p = 0.360), even when baseline glucose level and gender differences were accounted for. For incremental area under the curve there was no significant effect of activity group once gender and body fat percentage had been accounted for (p = 0.401). Those in the low activity group took 15 min longer to reach peak glucose level than those in the very active group (p = 0.012).

CONCLUSION

The results suggest that high levels of PA have a beneficial effect on postprandial blood glucose profiles when compared to low and moderate levels of activity.

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.

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.

30-minute postload plasma glucose levels during an oral glucose tolerance test predict the risk of future type 2 diabetes: the Hisayama Study

INTRODUCTION

To investigate the associations of 30 min postload plasma glucose (30 mPG) levels during an oral glucose tolerance test (OGTT) with the risk of future diabetes in a general Japanese population.

RESEARCH DESIGN AND METHODS

A total of 2957 Japanese community-dwelling residents without diabetes, aged 40-79 years, participated in the examinations in 2007 and 2008 (participation rate, 77.1%). Among them, 2162 subjects who received 75 g OGTT in a fasting state with measurements of plasma glucose level at 0, 30, and 120 min were followed up for 7 years (2007-2014). Cox's proportional hazards model was used to estimate HRs and their 95% CIs of each index for the development of type 2 diabetes using continuous variables and quartiles with adjustment for traditional risk factors. The influence of 30 mPG on the predictive ability was estimated with Harrell's C-statistics, integrated discrimination improvement (IDI), and the continuous net reclassification index (cNRI).

RESULTS

During follow-up, 275 subjects experienced type 2 diabetes. Elevated 30 mPG levels were significantly associated with increased risk of developing diabetes (p<0.01 for trend): the multivariable-adjusted HR was 8.41 (95% CI 4.97 to 14.24) for the highest versus the lowest quartile, and 2.26 (2.04 to 2.52) per 1 SD increase. This association was attenuated but remained significant after further adjustment for fasting and 2-hour postload plasma glucose levels. Incorporation of 30 mPG into the model including traditional risk factors with fasting and 2-hour postload plasma glucose levels for diabetes improved the predictive ability of type 2 diabetes (improvement in Harrell's C-statistics values: from 0.828 to 0.839, p<0.01; IDI: 0.016, p<0.01; cNRI: 0.103, p=0.37).

CONCLUSIONS

Elevated 30 mPG levels were associated with increased risk of diabetes, and inclusion of 30 mPG levels significantly improved the predictive ability for future diabetes, suggesting that 30 mPG may be useful for identifying high-risk populations for type 2 diabetes.

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

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.

Clinical utility of 30-min plasma glucose for prediction of type 2 diabetes among people with prediabetes: Ancillary analysis of the diabetes community lifestyle improvement program

AIMS

To examine the clinical utility of 30-min plasma glucose (30-min-PG) measurement during an oral glucose tolerance (OGTT) in predicting type 2 diabetes (T2DM).

RESEARCH DESIGN AND METHODS

Data from a 3-year, randomized, controlled, primary prevention trial among 548 Asian Indians with prediabetes were analyzed. Participants underwent OGTT with PG measurements at fasting, 30-min, and 2-h at baseline and annually until the end of the study. Multivariable Cox regression models were constructed to calculate the risk of developing diabetes based on 30-min-PG levels. Improvement in prediction performance gained by adding an elevated level of 30-min-PG over prediabetic categories was calculated using the area-under-curve (AUC), net-reclassification (NRI), and integrated discrimination improvement (IDI) statistics.

RESULTS

At the end of follow-up, 30.4% of individuals had been diagnosed with T2DM by ADA criteria. Based on the maximally selected log-rank statistics, the optimal 30-min-PG cut point for predicting incident T2DM was >182 mg/dl. Multivariable-adjusted Cox regression models showed an independent association between elevated 30-min-PG (>182 mg/dl) and incident diabetes (hazard ratio (95% CI): 1.85 [1.32, 2.59]; D_xy = 0.353, c-statistic = 0.676). The addition of an elevated 30-min-PG (>182 mg/dl) model significantly improved the prediction of diabetes (Δdeviance: -15.4; ΔAUC: 0.11; NRI_continuous: 0.51; IDI: 0.08) compared with IFG model alone) in individuals with prediabetes.

CONCLUSION

In prediabetic individuals, baseline 30-min-PG independently predicted T2DM and significantly improved reclassification and discrimination. Therefore, 30-min-PG should be considered as part of the routine testing in addition to FPG and 2-h-PG for better risk stratification.

Heritability of Curve Patterns in Oral Glucose Tolerance Test

Type 2 diabetes, which is caused by both genetic and environmental factors, may be diagnosed using the oral glucose tolerance test (OGTT). Recent studies demonstrated specific patterns in glucose curves during OGTT associated with cardiometabolic risk profiles. As the relative contribution of genetic and environmental influences on glucose curve patterns is unknown, we aimed to investigate the heritability of these patterns. We studied twins from the Danish GEMINAKAR cohort aged 18-67 years and free from diabetes at baseline during 1997-2000; glucose concentrations were measured three times during a 2-h OGTT. Heterogeneity of the glucose response during OGTT was examined with latent class mixed-effects models, evaluating goodness of fit by Bayes information criterion. The genetic influence on curve patterns was estimated using quantitative genetic modeling based on linear structural equations. Overall, 1455 twins (41% monozygotic) had valid glucose concentrations measured from the OGTT, and four latent classes with different glucose response patterns were identified. Statistical modeling demonstrated genetic influence for belonging to a specific class or not, with heritability estimated to be between 45% and 67%. During ∼12 years of follow-up, the four classes were each associated with different incidence of type 2 diabetes. Hence, glucose response curve patterns associated with type 2 diabetes risk appear to be moderately to highly heritable.

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.

Metabolic and Genetic Determinants of Glucose Shape After Oral Challenge in Obese Youths: A Longitudinal Study

CONTEXT

The time-to-glucose-peak following the oral glucose tolerance test (OGTT) is a highly reproducible marker for diabetes risk. In obese youths, we lack evidence for the mechanisms underlying the effects of the TCF7L2 rs7903146 variant on glucose peak.

METHODS

We analyzed the metabolic phenotype and the genotype for the TCF7L2 rs7903146 in 630 obese youths with normal (NGT) and impaired (IGT) glucose tolerance. Participants underwent a 3-hour, 9-point OGTT to estimate, using the oral minimal model, the disposition index (DI), the static (φstatic) and dynamic (φdynamic) components β-cell responsiveness and insulin sensitivity (SI). In a subgroup (n = 241) longitudinally followed for 2 years, we estimated the effect of time-to-glucose-peak on glucose tolerance change.

RESULTS

Participants were grouped into early (<30 minutes) and late (≥30 minutes) glucose peakers. A delayed glucose peak was featured by a decline in φstatic (P < .001) in the absence of a difference in φdynamic. The prevalence of T-risk allele for TCF7L2 rs7903146 variant significantly increased in the late peak group. A lower DI was correlated with higher glucose concentration at 1 and 2 hours, whereas SI was inversely associated with 1-hour glucose. Glucose peak <30 minutes was protective toward worsening of glucose tolerance overtime (odds ratio 0.35 [0.15-0.82]; P = .015), with no subjects progressing to NGT or persisting IGT, in contrast to the 40% of progressor in those with late glucose peak.

CONCLUSION

The prevalence of T-risk allele for the TCF7L2 rs7903146 prevailed in the late time-to-glucose peak group, which in turn is associated with impaired β-cell responsiveness to glucose (φ), thereby predisposing to prediabetes and diabetes in obese youths.

Obstructive Sleep Apnea Exacerbates Glucose Dysmetabolism and Pancreatic β-Cell Dysfunction in Overweight and Obese Nondiabetic Young Adults

PURPOSE

This study aimed to investigate the effects of obstructive sleep apnea (OSA) on the pancreatic β-cells dysfunction and their implications in the glucose dysmetabolism of overweight and obese nondiabetic young adults.

MATERIALS AND METHODS

The cross-sectional analysis included 422 subjects (261 males/161 females) with the mean age of 27.77 ± 7.51 years and average body mass index (BMI) of 34.84 ± 5.69 kg/m². All subjects underwent polysomnography (PSG), oral glucose tolerance-insulin releasing test (OGTT-IRT) and serum glycosylated hemoglobin A1 (HbA1c) measurement. The glucose metabolism and pancreatic β-cell function in relation to measures of OSA were determined adjustment for important confounders such as age and sex.

RESULTS

OSA subjects accounted for 54.91% in the normal glucose tolerance (NGT) group and 72.11% in the prediabetes (preDM) group (P =0.001). HbA1c was the highest in the preDM subjects with severe OSA. In the NGT subjects, the 1-h glucose level significantly elevated with the OSA severity, and the homeostasis model assessment-β (HOMA-β) was negatively related to nocturnal mean SpO₂ (P <0.05). In the preDM subjects, HOMA-β, early phase insulinogenic index (∆I₃₀/∆G₃₀), total area under the curve of insulin in 180 min (AUC-I₁₈₀), and the oral disposition index (DI_O) were the lowest in the severe OSA group. DI_O was associated with higher oxygen desaturation index (ODI) and lower nocturnal mean SpO₂, and AUC-I₁₈₀ was negatively related to TS90 (P <0.05).

CONCLUSION

Our study indicated higher prevalence of OSA in overweight and obese nondiabetic young adults, especially preDM subjects. The impaired glucose tolerance was observed early after glucose intake in the NGT subjects. OSA induces compensatory increase in the pancreatic β-cell function in the NGT subjects, while pancreatic β-cell dysfunction is present in the preDM subjects with severe OSA.

1 h Postload Glycemia Is Associated with Low Endogenous Secretory Receptor for Advanced Glycation End Product Levels and Early Markers of Cardiovascular Disease

We investigated the correlation of the soluble receptor for advanced glycation end products (sRAGE) and endogenous secretory RAGE (esRAGE) with markers of cardiovascular disease in subjects with normal glucose tolerance (NGT) and 1 h postload glucose ≥155 mg/dL after an oral glucose tolerance test. We stratified 282 subjects without a previous diagnosis of diabetes into three groups: 123 controls (NGT and 1 h postload glycemia <155 mg/dL), 84 NGT and 1 h postload glycemia ≥155 mg/dL (NGT 1 h high), and 75 subjects with impaired fasting glucose and/or impaired glucose tolerance (IFG/IGT). NGT 1 h high subjects exhibited lower esRAGE (0.36 ± 0.18 vs. 0.4 5 ± 0.2, p < 0.05) and higher S100A12 levels than controls (5684 (3193.2–8295.6) vs. 3960.1 (2101.8–7419), p < 0.05). Furthermore, they showed an increased pulse wave velocity (PWV) and intima–media thickness (IMT). No differences were found between the NGT 1 h high group and the IFG/IGT group regarding cardiometabolic profiles. After multiple regression analyses, esRAGE was associated with glycated hemoglobin (HbA_1c) and high-sensitivity C-reactive protein (hs-CRP). Age, HbA_1c, and esRAGE were the determinants of IMT, whereas S100A12 and systolic pressure were the determinants of PWV. The NGT 1 h high group exhibited low esRAGE levels and an altered cardiometabolic profile. HbA_1c, S100A12, and hs-CRP were associated with these alterations. In conclusion, subjects with NGT are not a homogeneous population, and they present different cardiovascular and glycometabolic risks.

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.

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.

Virtual Screening of Henna Compounds Library for Discovery of New Leads against Human Thymidine Phosphorylase, an Overexpressed Factor of Hand-Foot Syndrome

Background:

Capecitabine is one of the most effective and successful drugs for the treatment of uterine and colorectal cancer which has been limited in use due to occurrence of handfoot syndrome (HFS). Overexpression of human thymidine phosphorylase enzyme is predicted to be one of the main causes of this syndrome. Thymidine phosphorylase enzyme is involved in many cancers and inflammatory diseases and pyrimidine nucleoside phosphorylase family is found in a variety of organisms. Results of clinical studies have shown that topical usage of henna plant (Lawsonia inermis from the family of Lythraceae) could reduce the severity of HFS.

Methods:

By using in silico methods on reported compounds of henna, the present study is aimed at finding phytochemicals and chemical groups with the potential to efficiently interact with and inhibit human thymidine phosphorylase. Various compounds (825) of henna from different chemical groups (138) were virtually screened by the interface to AutoDock in YASARA Software package, against the enzyme structure obtained from X-ray crystallography and refined by homology modeling methods.

Results:

By virtual screening, i.e. docking of candidate ligands into the determined active site of hTP, followed by applying the scoring function of binding affinity, 71 compounds (out of 825 compounds) were estimated to have the likelihood to bind to the protein with an interaction energy higher than 10 kcal/mol (Concerning the sign of “binding energies”, please refer to the Methods section).

Conclusion:

Finally, diosmetin-3'-O-β-D-glucopyranoside (#219) and monoglycosylated naphthalene were respectively selected as the most potent phytochemicals and chemical groups. Flavonoid-like compounds with appropriate interaction energy were also considered as the most probable inhibitors. More investigations on henna compounds, are needed in order to approve their effectiveness and also to explore more anti-cancer, anti-inflammatory, anti-angiogenesis and even antibiotics.

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.

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.

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.