Predictability of 1-h postload plasma glucose concentration: A 10-year retrospective cohort study

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).

Efficacy of 1-hour postload plasma glucose as a suitable measurement in predicting type 2 diabetes and diabetes-related complications: A post hoc analysis of the 30-year follow-up of the Da Qing IGT and Diabetes Study

AIM

To evaluate whether 1-hour plasma glucose (1hPG) can be a comparable measurement to 2-hour plasma glucose (2hPG) in identifying individuals at high risk of developing diabetes.

METHODS

A total of 1026 non-diabetic subjects in the Da Qing IGT and Diabetes Study were included and classified according to baseline postload 1hPG. The participants were followed up and assessed at 6-, 20- and 30year follow-up for outcomes including diabetes, all-cause and cardiovascular mortality, cardiovascular disease (CVD) events, and microvascular disease. We then conducted a proportional hazards analysis in this post hoc study to determine the risks of developing type 2 diabetes and its complications in a '1hPG-normal' group (1hPG <8.6 mmol/L) and a '1hPG-high' group (≥8.6 mmol/L). The predictive values of 1hPG and 2hPG were evaluated using a time-dependent receiver-operating characteristic (ROC) curve.

RESULTS

Compared with the 1hPG-normal group, the 1hPG-high group had increased risk of diabetes (hazard ratio [HR] 4.45, 95% CI 3.43-5.79), all-cause mortality (HR 1.46, 95% CI 1.07-2.01), CVD mortality (HR 1.84, 95% CI 1.16-2.95), CVD events (HR 1.39, 95% CI 1.03-1.86) and microvascular disease (HR 1.70, 95% CI: 1.03-2.79) after adjusting for confounders. 1hPG exhibited a higher area under the ROC curve (AUC) for predicting diabetes than 2hPG during the long-term follow-up (AUC [1hPG vs. 2hPG]: 10 years: 0.86 vs. 0.84, p = 0.08; 20 years: 0.88 vs. 0.87, p = 0.04; 30 years: 0.85 vs. 0.82, p = 0.009).

CONCLUSIONS

Elevated 1hPG level (≥8.6 mmol/L) was associated with increased risk of developing type 2 diabetes and its long-term complications, and could be considered as a suitable measurement for identifying individuals at high risk of type 2 diabetes.

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 Antidiabetic Effects and Modes of Action of the Balanites aegyptiaca Fruit and Seed Aqueous Extracts in NA/STZ-Induced Diabetic Rats

Diabetes mellitus (DM) is a chronic metabolic disorder that threatens human health. Medicinal plants have been a source of wide varieties of pharmacologically active constituents and used extensively as crude extracts or as pure compounds for treating various disease conditions. Thus, the aim of this study is to assess the anti-hyperglycemic and anti-hyperlipidemic effects and the modes of action of the aqueous extracts of the fruits and seeds of Balanites aegyptiaca (B. aegyptiaca) in nicotinamide (NA)/streptozotocin (STZ)-induced diabetic rats. Gas chromatography-mass spectrometry analysis indicated that 3,4,6-tri-O-methyl-d-glucose and 9,12-octadecadienoic acid (Z,Z)- were the major components of the B. aegyptiaca fruit and seed extracts, respectively. A single intraperitoneal injection of STZ (60 mg/kg body weight (b.w.)) 15 min after intraperitoneal NA injection (60 mg/kg b.w.) was administered to induce type 2 DM. After induction was established, the diabetic rats were treated with the B. aegyptiaca fruit and seed aqueous extracts (200 mg/kg b.w./day) via oral gavage for 4 weeks. As a result of the treatments with the B. aegyptiaca fruit and seed extracts, the treated diabetic-treated rats exhibited a significant improvement in the deleterious effects on oral glucose tolerance; serum insulin, and C-peptide levels; liver glycogen content; liver glucose-6-phosphatase and glycogen phosphorylase activities; serum lipid profile; serum free fatty acid level; liver lipid peroxidation; glutathione content and anti-oxidant enzyme (glutathione peroxidase, glutathione-S-transferase, and superoxide dismutase) activities; and the mRNA expression of the adipose tissue expression of the insulin receptor β-subunit. Moreover, the treatment with fruit and seed extracts also produced a remarkable improvement of the pancreatic islet architecture and integrity and increased the islet size and islet cell number. In conclusion, the B. aegyptiaca fruit and seed aqueous extracts exhibit potential anti-hyperglycemic and anti-hyperlipidemic effects, which may be mediated by increasing the serum insulin levels, decreasing insulin resistance, and enhancing the anti-oxidant defense system in diabetic rats.

Patterns of Toll-Like Receptor Expressions and Inflammatory Cytokine Levels and Their Implications in the Progress of Insulin Resistance and Diabetic Nephropathy in Type 2 Diabetic Patients

Background: Diabetic nephropathy (DNP) is a type 2 diabetes mellitus (T2DM) chronic complication, which is the largest single cause of end-stage kidney disease. There is an increasing evidence of the role of inflammation and Toll-like receptors (TLRs) as part of innate immune system in its development and progression. In addition, Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) downward signaling causes the production of proinflammatory cytokines, which can induce insulin (INS) resistance in T2DM.

Objective: The goal of this study was to estimate the expression of TLRs (TLR2 and TLR4) in relation to inflammation and INS resistance in nephrotic type 2 diabetic patients with or without renal failure and to discuss the role of these TLRs in DNP progression.

Patients and Methods: In this study, blood samples were obtained from type 2 diabetic patients with or without renal failure, and patients with non-diabetic renal failure were compared to healthy controls. All participants were tested for analysis of fasting plasma glucose and serum insulin, kidney function tests, C-reactive protein (CRP), and proinflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and interleukin 6 (IL-6) as well as expression of TLR2 and TLR4 in peripheral blood (PB). Statistical analysis of data was done by using SPSS.

Results: Diabetic patients with renal failure exhibited significant increase in TLR2, TLR4 mRNA expression in PB in comparison with normal subjects, diabetic patients without renal failure and non-diabetic patients with renal failure. Both diabetic patients with or without kidney failure and non-diabetic patients with renal failure had increased TLR2 and TLR4 mRNA expression in association with increased levels of proinflammatory cytokines (TNF-α, IFN-γ, and IL-6) compared to normal subjects. The diabetic patients with kidney failure exhibited the highest elevation of TLRs, Th1 cytokines and CRP in association the highest record of insulin resistance.

Conclusion: Toll-like receptor 2 and Toll-like receptor 4 increased expression and Th2 cytokines may have an important role in the progression of DNP and deteriorations in insulin resistance in type 2 diabetic patients. Therefore, TLR2 and TLR4 may be a promising therapeutic target to prevent or retard DNP in type 2 diabetic patients.

Musa paradisiaca L. leaf and fruit peel hydroethanolic extracts improved the lipid profile, glycemic index and oxidative stress in nicotinamide/streptozotocin-induced diabetic rats

This study aimed to assess antihyperlipidemic, cardiac and antioxidant effects as well as mode of actions of Musa paradisiaca (M. paradisiaca) leaf and fruit peel hydroethanolic extracts in nicotinamide (NA)/streptozotocin (STZ)‐induced diabetic rats. Experimental diabetes mellitus was induced by a single intraperitoneal injection of STZ (60 mg/kg body weight), 15 min after intraperitoneal injection of NA (120 mg/kg body weight). NA/STZ‐induced diabetic rats were orally supplemented with M. paradisiaca leaf and fruit peel hydroethanolic extracts in a dose of 100 mg/kg body weight/day for 28 days. The treatment of NA/STZ‐induced diabetic rats with M. paradisiaca leaf and fruit peel extracts significantly decreased the elevated fasting and post‐prandial serum glucose, total cholesterol, triglycerides, LDL‐cholesterol and vLDL‐cholesterol levels and significantly increased the lowered serum insulin level, liver glycogen content, serum HDL‐cholesterol level, homeostasis model assessment‐insulin resistance (HOMA‐IS) and HOMA‐β cell function. The elevated cardiovascular risk indices in diabetic rats were significantly improved due to treatment with M. paradisiaca extracts. Concomitant with the increase in liver glycogen content, the glucose‐6‐phosphatase activity significantly decreased reflecting the decrease in hepatic glucose output. The heart function was potentially ameliorated as manifested by decrease in the elevated serum creatine kinase‐MB, lactate dehydrogenase and aspartate aminotransferase activities after treatments of diabetic rats with M. paradisiaca extracts. The elevated liver lipid peroxidation and the decline in liver glutathione content and superoxide dismutase, glutathione peroxidase and glutathione‐S‐transferase activities were significantly reversed by treatments. Thus, it can be concluded that M. paradisiaca leaf and fruit peel hydroethanolic extracts may have antihyperlipidemic and cardioprotective potentials in NA/STZ‐induced diabetic rats. These effects may be mediated via improvements in the glycemic state, β‐cell function, tissue insulin sensitivity, and antioxidant defense mechanism.

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.

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.

Antihyperglycemic Effects and Mode of Actions of Musa paradisiaca Leaf and Fruit Peel Hydroethanolic Extracts in Nicotinamide/Streptozotocin-Induced Diabetic Rats

The present study aimed to evaluate the antihyperglycemic effects of Musa paradisiaca (M. paradisiaca) leaf and fruit peel hydroethanolic extracts and to suggest their probable mode of actions in nicotinamide (NA)/streptozotocin (STZ)-induced diabetic rats. The leaf and fruit peel hydroethanolic extracts were analyzed by GC-MS that indicated the presence of phytol, octadecatrienoic acid, hexadecanoic acid, and octadecadienoic acid as major components in the leaf extract and vitamin E, octadecenamide, β-sitosterol, and stigmasterol as major phytochemicals in the fruit peel extract. Diabetes mellitus was induced by a single intraperitoneal injection of STZ (60 mg/kg body weight) dissolved in citrate buffer (pH 4.5), 15 minutes after intraperitoneal injection of NA (120 mg/kg body weight). The NA/STZ-induced diabetic rats were, respectively, treated with M. paradisiaca leaf and fruit peel hydroethanolic extracts at a dose of 100 mg/kg body weight/day by oral administration for 28 days. The treatment of NA/STZ-induced diabetic rats with leaf and fruit peel extracts significantly improved the impaired oral glucose tolerance and significantly increased the lowered serum insulin and C-peptide levels. The HOMA-IR (as the index of insulin resistance) and QUICKI (as a marker for insulin sensitivity), as well as HOMA-β cell function were significantly alleviated as a result of treatment of diabetic rats with leaf and fruit peel extracts. In association, the elevated serum-free fatty acids, TNF-α, and IL-6 levels were significantly decreased. In addition, the suppressed adipose tissue PPARγ, GLUT4, adiponectin, and insulin receptor β-subunit mRNA expressions were upregulated while the elevated adipose tissue resistin expression was downregulated in diabetic rats as a result of treatment with the leaf and peel extract. Based on these results, it can be concluded that M. paradisiaca leaf and fruit peel hydroethanolic extracts have antihyperglycemic effects which may be mediated via their insulinotropic and insulin-sensitizing effects.

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.

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.

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.

Abnormal 1-hour post-load glycemia during pregnancy impairs post-partum metabolic status: a single-center experience

PURPOSE

Recent evidence indicates that people with normal glucose tolerance (NGT) but 1-h post-load plasma glucose (1-h OGTT) ≥ 155 mg/dl have an increased risk for developing Type 2 diabetes mellitus (T2DM), determining a new risk category with deeper metabolic impairment. The aim of this study was to identify, among women with gestational diabetes (GDM), which alterations at OGTT during pregnancy are more frequently associated with 1-h OGTT ≥ 155 mg/dl at post-partum examination.

METHODS

Among 297 women affected by GDM, we retrospectively evaluated 244 resulted NGT after delivery. Based on post-partum glucose levels at 1-h OGTT, these people were divided into 188 cases (77.0%) with 1-h OGTT < 155 mg/dl (L-NGT) and 56 (23.0%) with 1-h OGTT ≥ 155 mg/dl (H-NGT).

RESULTS

Abnormal glucose levels at 1-h OGTT during pregnancy (≥ 180 mg/dl) were more frequent in H-NGT than in L-NGT (39.3 vs. 24.6%, odds ratio 3.7 [95% CI 1.4-9.6]; p = 0.016). Moreover, H-NGT showed more frequently the simultaneous alteration of all three OGTT plasma glucose values during pregnancy (10.7 vs. 2.1%, odds ratio 4.5 [95% CI 1.5-20.3]; p = 0.038) and less frequently the alteration of fasting plasma glucose alone (14.3 vs. 30.8%, odds ratio 0.4 [95% CI 0.1-0.7]; p = 0.028).

CONCLUSIONS

Abnormal 1-h OGTT during pregnancy predicts an increased risk for post-partum 1-h OGTT ≥ 155 mg/dl in women with previous GDM. Even if NGT after delivery, these women may require a closer long-term post-partum follow-up, being at higher risk to develop future glucose intolerance.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Diagnostic performance of glycated hemoglobin for diabetic retinopathy in non-diabetic older overweight/obese African-Americans

OBJECTIVES

Although clinicians do not routinely screen for diabetic retinopathy in non-diabetic patients, previous studies have shown that diabetic retinopathy can occur in patients with prediabetes. However, due to the limitations of glycated hemoglobin (HbA1c) in overweight/obese subjects, African-Americans and older adults, little is known about the correlation between HbA1c and diabetic retinopathy in non-diabetic older overweight/obese African-Americans. The aims of this study were to determine the association between HbA1c and diabetic retinopathy, and the optimal diagnostic threshold of HbA1c that predicts diabetic retinopathy in non-diabetic older overweight/obese African-Americans.

METHODS

The 2005-2012 data from the U.S. National Health and Nutrition Examination Surveys (NHANES) were utilized for this study. Prevalence odds ratios from logistic regression analyses were used to estimate risks of diabetic retinopathy across HbA1c categories, adjusting for age, sex, and hypertension. Receiver operating characteristic curve was used to determine diagnostic cutoff point of HbA1c for prevalent diabetic retinopathy.

RESULTS

There were gradients of increasing prevalence and odds of diabetic retinopathy with increasing HbA1c in non-diabetic overweight/obese African-Americans 50years of age and older. HbA1c cut-off point of 5.2% (AUC=.726, 95% CI=0.696-0.756) was found to maximize sensitivity [93.5%; 95% CI: 83.2-95.7] for diabetic retinopathy, though specificity [22.1%; 95% CI 19.9-32.8] was low.

CONCLUSION

Current criteria for diagnosis of prediabetes are effective in identifying many older overweight/obese African Americans with diabetic retinopathy. Based on our analysis, a lower HbA1c of 5.2% could serve as a more sensitive cutoff point for defining prediabetes in this population subgroup.

Follow-up duration influences the relative importance of OGTT and optimal timing of glucose measurements for predicting future type 2 diabetes

OBJECTIVE

To examine the impact of follow-up duration on the incremental prognostic yield of a baseline oral glucose tolerance test (OGTT) for predicting type 2 diabetes and to assess the discrimination ability of blood glucose (BG) obtained at different time points during OGTT.

DESIGN

A prospective, population-based cohort study (Malmö Preventive Project) with inclusion of subjects from 1974 to 1992.

METHODS

A total of 5256 men without diabetes, who had BG measured at 0, 20, 40, 60, 90, and 120 min during OGTT (30 g/m2 glucose), were followed for 30 years. Incident type 2 diabetes was recorded using registries. The performance of OGTT added to a clinical prediction model (age, body mass index (BMI), diastolic blood pressure, fasting BG, triglycerides, and family history of diabetes) was assessed using Harrell's concordance index (C-index) and integrated discrimination improvement (IDI).

RESULTS

Median age was 48 years, mean BMI 24.9 kg/m2, and mean fasting BG 4.7 mmol/L. Models with added post-load BG performed better than the clinical model (C-index: P = 0.08 for BG at 120 min at 5 years, otherwise P ≤ 0.045; IDI: P ≥ 0.06 for BG at 60 and 90 min at 5 years, otherwise P ≤ 0.01). With a longer follow-up duration, C-index decreased, and the C-index increase associated with OGTT was attenuated. Models including BG at 60 or 90 min performed significantly better than the model with BG at 120 min, evident beyond follow-up of 10 and 5 years, respectively.

CONCLUSIONS

OGTT provided incremental prognostic yield for type 2 diabetes prediction. BG measured at 60 or 90 min provided better discrimination than BG at 120 min.