Glucose Tolerance Test Research Articles

The Inhibitory Effects of NCT503 and Exogenous Serine on High-Selenium Induced Insulin Resistance in Mice

Objective: This study aims to identify whether the development of insulin resistance (IR) induced by high selenium (Se) is related to serine deficiency via the inhibition of the de novo serine synthesis pathway (SSP) by the administrations of 3-phosphoglycerate dehydrogenase (PHGDH) inhibitor (NCT503) or exogenous serine in mice. Method: forty-eight male C57BL/6J mice were randomly divided into four groups: adequate-Se (0.1 mgSe/kg), high-Se (0.8 mgSe/kg), high-Se +serine (240 mg/kg/day), and high-Se +NCT503 (30 mg/kg, twice a week) for 5 months. The glucose tolerance test (GTT) and insulin tolerance test (ITT) were used to confirm the development of IR in mice with high-Se intake, and fasting blood glucose levels were measured monthly. The Se contents in plasma and tissues were detected by ICP-MS. The levels of insulin (INS), homocysteine (HCY), and serine in plasma were tested by ELISA. Western blot analyses were conducted to evaluate the protein expressions of glutathione peroxidase 1 (GPX1), selenoprotein P (SELENOP) and PHGDH, the PI3K-AKT-mTOR pathway, folate cycle (SHMT1, MTHFR), and methionine cycle (MS). Results: An IR model was developed in mice from the high-Se group with elevated fasting blood glucose and INS levels, impaired glucose tolerance, and reduced insulin sensitivity, but not in both the high-Se +serine group and the high-Se +NCT503 group. Compared with the high-Se and high-Se +serine groups, the expressions of GPX1 and SELENOP significantly decreased for the high-Se +NCT503 group in the liver, muscle, and pancreas tissues. The expression of PHGDH of high-Se group was significantly higher than that of the adequate-Se group in the liver (p < 0.05) and pancreas (p < 0.001). Also, the expected high expression of PHGDH was effectively inhibited in mice from the high-Se +serine group but not from the high-Se +NCT503 group. The expression of p-AKT (Ser-473) for the high-Se group was significantly lower than that of the adequate-Se group in the liver, muscle, and pancreas. Conclusions: The IR induced by high-Se intake in the body has been confirmed to be partially due to serine deficiency, which led to the initiation of SSP to produce endogenous serine. The supplementations of exogenous serine or inhibitors of PHGDH in this metabolic pathway could be used for the intervention.

Assessment of the impact of VDR polymorphisms on selected hormonal, metabolic and mineral balance markers in young women with hyperandrogenism.

Hyperandrogenism is a frequently recognized endocrine imbalance in which there is excessive production of androgens. The purpose of the study was to investigate the impact of vitamin D receptor (VDR) gene polymorphisms on chosen bone metabolism and biochemical parameters in women with hyperandrogenism. Eighty young females with hyperandrogenism were enrolled in the study, in whom selected parameters of bone turnover, endocrine and metabolic parameters were determined. Two polymorphisms of the VDR gene were analyzed: rs731236 (TaqI) and rs1544410 (BsmI), using real-time polymerase chain reaction (PCR). Statistical tests were performed in this research with the program SPSS Statistics 17.0 for Windows. The rs731236 and rs1544410 polymorphisms of the VDR gene turned out to be statistically significantly related to the concentration of insulin determined in the 60 'glucose tolerance test. There was no relationship between the studied polymorphisms of the VDR gene and the determined parameters of bone metabolism and other biochemical parameters. The research presented that VDR gene variants may influence disturbances in carbohydrate metabolism in young women with hyperandrogenism.

Dapagliflozin combined with metformin improves blood glucose, bone metabolism and bone mineral density in elderly patients with type 2 diabetes mellitus complicated with osteoporosis.

The incidence of type 2 diabetes mellitus (T2DM) complicated with osteoporosis (OP) (T2DM-OP) is growing. Dapagliflozin and metformin are commonly prescribed to manage glycemic levels in T2DM patients. We investigated the clinical efficacy of combining dapagliflozin with metformin in elderly patients with T2DM-OP. Totally 144 T2DM-OP patients were prospectively enrolled and allocated into two groups: the Metformin and Dapagliflozin + Metformin groups. Each group received treatment for 12 months. Fasting peripheral blood samples were collected before and after 12 months of treatment. Glycemic parameters and bone metabolic parameters were measured using oral glucose tolerance test, automatic biochemical analyzers, or liquid chromatography. Bone mineral density (BMD) changes at lumbar vertebrae (L1-4), femoral neck (FN) and total hip (TH) were assessed using dual-energy X-ray bone mineral densitometry. Pain severity was evaluated using the visual analog scale (VAS). The total effective rate, fracture incidence, and adverse reaction rate were also evaluated. After 12 months, both groups showed improvements in glycemic parameters, bone metabolic parameters, and BMD at L1-4, FN, and TH, and reductions in VAS scores. The Dapagliflozin + Metformin group exhibited more significant improvements. The overall effective rate was higher and fracture incidence, was lower in Dapagliflozin + Metformin group, with comparable rates of adverse reactions and safety profiles between the two groups. Taken together, treatment with a combination of dapagliflozin and metformin led to improvements in blood glucose levels, bone metabolism, and BMD in elderly patients with T2DM-OP, demonstrating superior efficacy and safety compared to metformin monotherapy.

Gestational diabetes and mental health: longitudinal analysis of data from the GEMS randomized trial.

There is limited high-quality evidence about perinatal mental health among women with gestational diabetes. We aimed to assess the risks and longitudinal changes in anxiety, depression, and health-related quality of life comparing women with gestational diabetes and those without among a contemporary cohort of pregnant women. Prospective cohort study of participants in the GEMS Trial. Women with a singleton pregnancy were eligible if they had a 75-g diagnostic oral glucose-tolerance test between 24 and 32 weeks' gestation, provided written informed consent, and completed questionnaires about anxiety, depression, and health-related quality of life at the study time points. There were no differences in risk for anxiety (RR 1.13, 95% CI 0.86, 1.49; p = 0.39) or depression (RR 1.08, 95% CI 0.78, 1.50; p = 0.64) between the two groups at 36 weeks' gestation or 6 months postpartum [anxiety: (RR 1.21, 95% CI 0.90, 1.63; p = 0.21); depression: (RR 0.84, 95% CI 0.55, 1.28; p = 0.43]. However, at 36 weeks' gestation participants with gestational diabetes reported better physical functioning, and at 6 months postpartum, better mental functioning (mean difference (MD) in scores 1.28, 95% CI 0.25, 2.30; p = 0.01) although worse physical functioning (MD -2.99, 95% CI -3.90, -2.07; p = < 0.001) compared to participants without. The risk for poor mental health during the perinatal period does not differ importantly among women diagnosed and treated for gestational diabetes compared to the general pregnant population.

Effects of Short-Term Low Energy Availability on Metabolism and Performance-Related Parameters in Physically Active Adults

Background/Objectives: Low energy availability (LEA) can cause impaired reproductive function, bone health issues, and suppressed immune function, and may result in decreased performance and overall health status. The purpose of this study was to investigate adaptions of body composition, blood status, resting metabolic rate, and endurance performance to gain more comprehensive insights into the symptoms of LEA and the adaptive effects in the athlete population (active women (n = 11) and men (n = 11)). Methods: Three treatments were defined as 45 (EA45, control), 30 (EA30), and 10 (EA10) kcal/kg FFM/day and randomly assigned. Pre- and post-intervention measurements were performed through blood sampling, bioelectrical impedance analysis, resting metabolic rate measurement, the oral glucose tolerance test (OGTT), and the incremental endurance test to exhaustion. Results: There was a significant reduction in body weight and fat mass in EA10 compared to EA45 (p ≤ 0.05). Blood serum levels were altered in triglyceride, uric acid, and creatinine concentrations in EA10 compared to EA45 (p ≤ 0.05). Furthermore, blood glucose was still accumulated after 120 min during OGTT in EA10 compared to EA45 (p ≤ 0.05). The respiratory exchange ratio was reduced during submaximal stages of the incremental treadmill test to exhaustion without influencing performance output after treatment EA10 (p ≤ 0.05). However, the resting metabolic rate did not change (p &gt; 0.05). Conclusions: In conclusion, this short-term study indicates that energy restriction can lead to several metabolic-related adaptations, which suggests that the availability and regulation of glucose and fats are significantly influenced after only five days of LEA in physically active women and men. Future research should focus on longer exposures of LEA and sex-specific comparisons (including the menstrual cycle) on LEA symptoms.

Beta cell function and global glucose metabolism are impaired in Dp(16)1Yey mouse model of Down syndrome.

Down syndrome (DS) or trisomy 21 is the most prevalent genetic disorder in the world. In addition to common symptoms such as intellectual disabilities and morphological abnormalities, several comorbidities are associated with DS, including metabolic dysfunction. Obesity and diabetes are more prevalent in people with DS compared with the general population. However, the mechanisms linking obesity/diabetes to DS remain poorly understood. Systematic investigation of metabolic disorders in animal models of DS is scarce. We used the Dp(16)1Yey mouse model of DS to evaluate the energy and glucose metabolism in both male and female Dp(16)1Yey mice at 3 and 6 months of age. We assessed the whole-body glucose metabolism by glucose and insulin tolerance tests, and investigated the pancreatic functions in terms of insulin synthesis, ß cell mass and the glucose-induced insulin secretion in vivo. We show that Dp(16)1Yey mice do not present signs of obesity when they are fed with chow diet. However, these mice are glucose intolerant and insulin resistant, and exhibit dysfunctions of their endocrine pancreas, reflected by decreased insulin content and defective glucose-induced insulin secretion (GIIS) in vivo. The impairment of metabolic parameters is similar between males and females trisomic mice, indicating the absence of metabolic sexual dimorphism in this model. Our study suggests that Dp(16)1Yey model is suitable for the assessment of metabolic disorders associated with DS.

Impact of Maternal Macronutrient Intake on Large for Gestational Age Neonates’ Risk Among Women with Gestational Diabetes Mellitus: Results from the Greek BORN2020 Cohort

Background/Objectives: The effect of maternal macronutrient composition on the risk of large for gestational age (LGA) neonates among women with gestational diabetes mellitus (GDM) is not well understood. This study aimed to investigate these associations in a pregnant cohort in Northern Greece, considering both pre-pregnancy and early pregnancy dietary intake, and stratifying women by pre-pregnancy body mass index (BMI). Methods: From a total of 797 eligible pregnant women, the 117 (14.7%) who developed GDM (and thus were included in the study) completed the validated Food Frequency Questionnaires (FFQs). Macronutrient intake was assessed for the six months before pregnancy and until mid-gestation, prior to the oral glucose tolerance test. Data were compared with European Food Safety Authority (EFSA) guidelines, and participants were stratified by pre-pregnancy BMI (normal vs. overweight/obese). Multivariate logistic regression was used to estimate adjusted odds ratios (aORs) for LGA risk. Results: In normal-BMI women with GDM, higher dietary fiber (aOR = 1.39) and vegetable protein (aOR = 1.61) intake before pregnancy were both significantly associated with an increased risk of LGA. During early pregnancy, the elevated risk from vegetable protein persisted (aOR = 1.51). Among overweight/obese women, no significant pre-pregnancy associations were observed. However, during early pregnancy, a higher percentage of total carbohydrate intake was linked to increased LGA risk (aOR = 1.11), while maintaining saturated fatty acids “as low as possible” reduced the odds of LGA (aOR = 0.71). Elevated vegetable protein intake also increased LGA risk (aOR = 1.61). Conclusions: Maternal macronutrient intake prior to and during early pregnancy may influence LGA risk in GDM, with distinct patterns according to pre-pregnancy BMI. These findings underscore the importance of tailoring dietary recommendations—especially regarding fiber, vegetable protein, carbohydrates, and saturated fat—to mitigate the risk of LGA in women with GDM.

Intermittent standing does not acutely improve postprandial metabolism in university students.

Height-adjustable workstations offer a practical strategy to reduce sedentary behaviour in student populations, but the effect of standing intervals on young adults' metabolic health remains uncertain. This study investigated the acute impact of breaking up sitting time with intermittent standing on postprandial metabolic responses in university students. Using a randomised, cross-over design, 23 participants (13 females, 10 males; age, 24 ± 5 years; BMI, 23.2 ± 3.1 kg/m2) completed two trials: 2 hours of uninterrupted sitting (SIT); and 2 hours alternating between sitting and standing every 30 minutes (STAND). During this period, participants underwent an oral glucose tolerance test, with [glucose] and [insulin] measured. Ad libitum food intake post intervention was also measured. No significant effects between trials nor trial × time interaction was found for [glucose] or [insulin] (all p > 0.05). The postprandial iAUC did not differ for [glucose] (p = 0.824; SIT: 222 ± 83 mmol/L; STAND: 225 ± 90 mmol/L) or [insulin] (p = 0.269; SIT: 17507 ± 9738 pmol/L; STAND: 15649 ± 10181 pmol/L). There were no differences in energy or macronutrient intake between trials. These findings indicate that interrupting sitting with 30-minute standing intervals does not improve postprandial metabolic responses in young, normal-weight adults.

Anorexia nervosa is associated with higher brain mu-opioid receptor availability.

Anorexia nervosa (AN) is a severe psychiatric disorder, characterized by restricted eating, fear to gain weight, and a distorted body image. Mu-opioid receptor (MOR) functions as a part of complex opioid system and supports both homeostatic and hedonic control of eating behavior. Thirteen patients with AN and thirteen healthy controls (HC) were included in this study. We measured (1) MOR availability with [11C]carfentanil positron emission tomography (PET), (2) brain glucose uptake (BGU) with 2-deoxy-2[18F]fluoro-D-glucose ([18F]FDG) PET during hyperinsulinemic-euglycemic clamp and (3) blood-oxygen-level-dependent signal with functional magnetic resonance imaging. All subjects underwent a screening visit consisting of physical examination, anthropometric measurements, fasting blood samples, an oral glucose tolerance test, psychiatric assessment, and an inquiry regarding medical history. Body fat mass (%) was measured and M value was calculated. MOR availability from caudate and putamen was higher in patients with AN and those from nucleus accumbens (NAcc) and thalamus showed the higher trend in patients with AN. There was no area where MOR availability was lower in patients with AN. BGU was not different between AN and HC. MOR availability and BGU were negatively correlated in caudate, NAcc and thalamus and showed the trend of negative association in putamen. In conclusion, AN is associated with higher MOR availability in the brain regions implicated in reward processing, while BGU remains unaltered. Therefore, the endogenous opioid system might be one of the key components underlying AN. This better understanding of AN could support the development of new treatments for AN.

Prevalence of neoplasms in acromegaly: a Turkish single-center retrospective study

Aims: This study aimed to investigate the prevalence of benign and malignant neoplasms and to assess associated clinical conditions in patients with acromegaly. Methods: In this single center, retrospective and observational study, data from 71 patients with acromegaly followed at an endocrinology and metabolism diseases outpatient clinic between January 2010 and December 2023 were reviewed through the hospital's electronic database. Patients' medical histories, demographic data, blood examinations, medications, pituitary MRI scans, thyroid ultrasound, mammography, colonoscopy, endoscopy, and pathology reports were evaluated. Acromegaly diagnosis was based on elevated insulin-like growth factor-1 (IGF-1) levels and unsuppressed growth hormone (GH) levels after oral glucose tolerance testing. The chi-square test and Mann-Whitney U test were used to compare patients with malignancy to other patients in terms of demographic and clinical characteristics. Results: The study included predominantly female patients (60.6%) with an average age of 55.6 years. The mean age at diagnosis was 44.3±11.3 years, and the mean disease duration was 11.3±8.4 years. Malignancies, including breast, thyroid, and colorectal cancers, were detected in 9.9% of patients. Additionally, thyroid nodules were present in 62% of patients, and colon polyps in 14.1%. No significant differences were observed in clinical features including age, gender, disease duration, GH levels, IGF-1 levels, adenoma size, or remission frequency between patients with and without malignancy (p&gt;0.05 for all). Conclusion: This study reveals an increased prevalence of breast, colon, and thyroid cancers in patients with acromegaly. Performing cancer screenings in patients with acromegaly more comprehensively and at an earlier stage compared to the normal population may be beneficial.

Preparation and Hypoglycemic Effect of Magnolia Officinalis Polysaccharide Oral Liquid.

In this paper, an oral liquid containing Magnolia officinalis polysaccharide was formulated and its hypoglycemic effects were investigated. An orthogonal test was conducted based on single-factor experiments to optimize the formulation guided by sensory evaluations. Its stability and safety were also assessed. The oral liquid was administered via gavage to STZ-induced diabetic mice at low (2.5mL/kg), medium (5mL/kg) and high (10mL/kg) doses. Blood glucose levels were monitored weekly. After 8weeks of treatment, the oral glucose tolerance test (OGTT) was performed and fasting insulin levels, lipid profiles, oxidative stress levels in serum and liver, and the activities of hexokinase (HK) and pyruvate kinase (PK) in the liver were measured. Results indicated that the optimal formulation contained 0.2% steviol glycosides, 0.2% ascorbic acid, a pH of 5.0, and 0.5% ginger juice, yielding a sensory evaluation score of 94 ± 0.58. The oral liquid remained stable at room temperature for 12months and passed acute oral toxicity testing. After 8weeks, diabetic mice exhibited a significant reduction in blood glucose levels (P < 0.01), enhanced glucose metabolism, increased fasting insulin levels, and decreased lipid levels. Additionally, antioxidant capacity improved, and HK and PK activities increased significantly in the diabetic mice. In conclusion, the Magnolia officinalis polysaccharide oral liquid demonstrated potential antidiabetic effects by promoting glucose utilization in peripheral tissues, increasing fasting insulin levels, and enhancing antioxidant capacity alongside HK and PK activities. This formulation could represent a promising hypoglycemic health product.

Timing of Resistance Exercise and Cardiometabolic Outcomes in Adults with Prediabetes: A Secondary Analysis.

Objective: The objective of this study was to explore if the time of day (AM vs PM) resistance exercise is performed influences glucose and insulin concentrations, body composition, and muscular strength in adults with prediabetes. Methods: A secondary data analysis was conducted using data from the "Resist Diabetes" study, a phase II exercise intervention. Participants (Age:59.9±5.4 yrs; BMI:33±3.7 kg/m2) with prediabetes and overweight or obesity were categorized into AM (N=73) or PM (N=80) exercisers based on when they completed all of their supervised exercise sessions during a 12-week, 2x/week resistance exercise intervention. Blood glucose and insulin derived from oral glucose tolerance tests, body composition, and muscular strength were assessed pre and post resistance exercise training. Inverse propensity score weighting approach was used to estimate the efficacy of AM/PM exercise on the change of clinical responses. Paired samples t-test was used to compare pre-/post outcomes within AM/PM group. Results: No differences between AM and PM exercisers were detected in the change in glucose or insulin areas under the curve (AUC), body composition, or muscular strength. When exploring within-group changes, PM exercisers reduced glucose AUC (change: -800.6 mg/dl*120 min; p=0.01), whereas no significant change was detected for AM exercisers (change: -426.9 mg/dl*120 min; p=0.26). Only AM exercisers increased fat-free mass (change: 0.6 kg; p=0.001). Conclusions: The time of day of resistance exercise is performed may have some impact on glucose concentrations and body composition response. Future randomized clinical trials are needed to understand how exercise timing influences cardiometabolic outcomes in at-risk adults.

Predicting Gestational Diabetes Mellitus in the first trimester using machine learning algorithms: a cross-sectional study at a hospital fertility health center in Iran

BackgroundGestational Diabetes Mellitus (GDM) is a common complication during pregnancy. Late diagnosis can have significant implications for both the mother and the fetus. This research aims to create an early prediction model for GDM in the first trimester of pregnancy. This model will help obstetricians and gynecologists make appropriate decisions for treating and preventing GDM complications.MethodsThis applied descriptive study was conducted at the fertility health center of Vali-e-Asr Hospital in Tehran, Iran. The dataset was collected from the records of pregnant women registered in the hospital’s system from 2020 to 2022. Risk factors for designing predictive models were identified through literature review, expert opinions, and clinical specialists’ input. The extracted information underwent preprocessing, and six machine learning (ML) methods were developed and evaluated for GDM prediction in the first trimester of pregnancy: decision tree (DT), multilayer perceptron (MLP), k-nearest neighbors (KNN), Naïve Bayes (NB), random forest (RF), and extreme gradient boosting (XGBoost).ResultsModels were evaluated using accuracy, precision, sensitivity, and the area under the receiver operating characteristic curve (AUC). Based on the glucose tolerance test (GTT) results, the RF model achieved the best performance in GDM prediction, with 89% accuracy, 86% precision, 92% recall, and 94% AUC, using demographic variables, medical history, and clinical findings. In modeling based on insulin consumption, the RF model achieved the best results with 62% accuracy, 60% precision, 63% recall, and 63% AUC in predicting GDM using demographic variables and medical history.ConclusionThe results of this study demonstrate that ML algorithms, especially RF, have acceptable accuracy in the early prediction of GDM during the first trimester of pregnancy.

Can First Trimester Plasma Protein A Level Predict Gestational Diabetes Mellitus

Aim: Gestational diabetes mellitus (GDM), a condition with multifactorial etiology and adverse perinatal consequences, affects approximately 15% of pregnancies globally, with higher prevalence in certain populations, such as Türkiye. The role of pregnancy-associated plasma protein-A (PAPP-A) on GDM risk remains unclear. This prospective study aimed to assess whether first-trimester maternal PAPP-A levels are predictive of GDM. Material and Method: This study involved 573 singleton pregnancies in women aged 18 to 45 years, conducted at a tertiary maternity hospital. PAPP-A and free β-hCG were assessed, and GDM screening was carried out using a 75 g oral glucose tolerance test. Comprehensive statistical analyses were applied to evaluate the findings. Results: Of the participants, 28.09% were diagnosed with GDM. GDM group exhibited significantly lower PAPP-A MoM levels compared to controls (p=0.042). ROC analysis revealed limited predictive utility, with a PAPP-A threshold of 0.99 demonstrating 52.3% sensitivity and 51.7% specificity. Logistic regression identified low PAPP-A levels, advanced maternal age, and higher body mass index (BMI) as independent GDM risk factors. Conclusion: While the findings underscore a potential association between PAPP-A levels and GDM, the predictive capacity of PAPP-A alone is modest. Future research should explore integrated predictive models incorporating PAPP-A and other biomarkers for improved early GDM screening.

Radon Exposure and Gestational Diabetes

Understanding environmental risk factors for gestational diabetes (GD) is crucial for developing preventive strategies and improving pregnancy outcomes. To examine the association of county-level radon exposure with GD risk in pregnant individuals. This multicenter, population-based cohort study used data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) cohort, which recruited nulliparous pregnant participants from 8 US clinical centers between October 2010 and September 2013. Participants who had pregestational diabetes or were missing data on GD or county-level radon measurements were excluded from the current study. Data were analyzed from September 2023 to January 2024. County-level radon data were created by the Lawrence Berkeley National Laboratory based on the Environmental Protection Agency's short- and long-term indoor home radon assessments. Radon exposure was categorized into 3 groups: less than 1, 1 to less than 2, and 2 or more picocuries (pCi)/L (to convert to becquerels per cubic meter, multiply by 37). Because radon, smoking, and fine particulate matter air pollutants (PM2.5) may share similar biological pathways, participants were categorized by joint classifications of radon level (<2 and ≥2 pCi/L) with smoking status (never smokers and ever smokers) and radon level with PM2.5 level (above or below the median). The main outcome was GD, identified based on glucose tolerance testing and information from medical record abstraction. Multiple logistic regression models were used to assess the association between radon exposure and GD. Among the 9107 participants, mean (SD) age was 27.0 (5.6) years; 3782 of 9101 (41.6%) had ever used tobacco. The mean (SD) county-level radon concentration was 1.6 (0.9) pCi/L, and 382 participants (4.2%) had GD recorded. After adjusting for potential confounders, individuals living in counties with the highest radon level (≥2 pCi/L) had higher odds of developing GD compared with those living in counties with the lowest radon level (<1 pCi/L) (odds ratio [OR], 1.37; 95% CI, 1.02-1.84); after additional adjustment for PM2.5, the OR was 1.36 (95% CI, 1.00-1.86). Elevated odds of GD were also observed in ever smokers living in counties with a higher (≥2 pCi/L) radon level (OR, 2.09; 95% CI, 1.41-3.11) and participants living in counties with higher radon and PM2.5 levels (OR, 1.93; 95% CI, 1.31-2.83), though no statistically significant interactions were observed. This cohort study suggests that higher radon exposure is associated with greater odds of GD in nulliparous pregnant individuals. Further studies are needed to confirm the results and elucidate the underlying mechanisms, especially with individual-level residential radon exposure assessment.

Exploring insulin resistance and pancreatic function in individuals with overweight and obesity: Insights from OGTTs and IRTs.

To investigate insulin resistance and pancreatic β-cell function in overweight or obese people under the same glucose tolerance conditions. The subjects were categorized based on the results of the oral glucose tolerance test (OGTT) and the BMI classification criteria. Basal and postprandial glucose concentrations, insulin concentrations, pancreatic β-cell function (HOMA-β), the insulin resistance index (HOMA-IR), and the insulin early secretion index (ΔI30/ΔG30) were compared between the different weight groups. Among individuals with similar glucose tolerances, those in the obese group presented higher HOMA-β, HOMA-IR, and ΔI30/ΔG30 values than did those in the normal weight and overweight groups. Additionally, in individuals with normal glucose tolerance and early diabetes, OGTT 1-h plasma glucose concentrations demonstrated a stronger correlation with early insulin secretion across different body weights. When the same glucose-tolerant population was grouped by weight, OGTTs were significantly less different than IRTs. Therefore, integrating both tests is the optimal approach. In individuals with preobesity, there is an increase in pancreatic β-cell function to maintain normal blood glucose levels. As the disease progresses, obesity substantially increases insulin resistance, which acts as a disease-promoting factor. Furthermore, OGTT 1-h plasma glucose concentrations are strongly correlated with insulin secretion in normal or early diabetic populations.

Differences in target organ damage in individuals with intermediate hyperglycemia and type 2 diabetes identified by 1-hour plasma glucose during an oral glucose tolerance test

Aims: The International Diabetes Federation (IDF) has recently recommended determination of 1-hour glucose during an oral glucose tolerance test (OGTT) to diagnose intermediate hyperglycemia (IH) and type 2 diabetes (T2D). Herein, we investigated the implications of IDF recommendation for characterizing the risk of cardiovascular target organ damage including left ventricular mass normalized by body surface area (LVM index [LVMI]), and myocardial mechano-energetic efficiency normalized by LVM (MEEi) in individuals with IH and T2D. Methods: LVMI, and MEEi were assessed in 1847 adults classified on the basis of fasting, 1-hour and 2- hour glucose during an OGTT according to the IDF recommendation as having normal glucose tolerance (NGT, n = 736), isolated impaired fasting glucose (iIFG, n = 105), IH (n = 676), and newly diagnosed T2D (n = 330). Results: As compared with NGT group, individuals with either IH or T2D exhibited significantly higher LVMI (97 ± 26, 109 ± 30, and 116 ± g/m2, P < 0.001, respectively), and a decrease in MEEi (0.42 ± 0.11, 0.37 ± 0.10, and 0.35 ± 0.11 ml/sec*g-1, P < 0.001, respectively). LVMI, and MEEi did not differ between NGT and iIFG groups. Conclusion: The thresholds of 1-hour post-load glucose proposed by IDF as diagnostic criteria for IH and T2D are capable of detecting individuals at risk of cardiovascular target organ damage.

Serum resistin increases in gestational diabetes but does not differ among various trimesters.

Resistin is inflammatory adipocytokine released from adipose and other tissue. It is thought that it is related to insulin resistance and pathogenesis of gestational diabetes mellitus (GDM). This study was aimed to determine the level of serum resistin in mothers with GDM and normal glucose tolerance (NGT) in all trimesters to see whether it differs among different trimesters as well as between GDM and NGT. This cross-sectional study included 81 pregnant women with GDM and 86 NGT after challenging three samples of 75gm oral glucose tolerance test (OGTT) following WHO-2013 criteria. Resistin was measured from serum samples obtained in fasting state during OGTT. Resistin was measured by sandwich ELISA method. Resistin level [13.2(9.85, 16.0) vs. 4.66(3.53, 5.96), median (IQR); p<0.001] was significantly higher in GDM than NGT group. This was also observed for all the trimesters [1st p<0.001; 2nd p<0.001; and 3rd p<0.001 respectively] between the two groups. However, resistin showed no significant difference (p=NS for all) within each group among the three trimesters. By binary logistic regression, resistin was observed as an independent predictor for GDM (p<0.001). On the other hand, Receiver operating characteristics (ROC) curve analysis explored resistin (AUC=0.856; p<0.001) as a good predictor for GDM. Resistin is statistically and significantly higher in GDM than that of NGT group irrespective of gestational age. It does not differ among three trimesters within any of GDM or NGT mothers. Resistin is a good predictor for GDM.

Therapeutic Potential of Brassica carinata Microgreens Extract in Alleviating Symptoms of Type 2 Diabetes in Wistar Rats.

Microgreens of Brassica plants have attracted increasing research interest in the management of the prevailing epidemic of Type 2 diabetes mellitus (T2DM) because of their high nutritional value. This study evaluated the antidiabetic effects of Brassica carinata Microgreens Ethanolic Extract (BMEE) in type-2 diabetic rats. For the normoglycemic assay, rats were divided into five groups and received a single oral dose of 100, 250, and 500 mg/kg of BMEE while the control groups received distilled water and Glibenclamide. Fasting blood glucose (FBG) levels were determined on a weekly basis for 28 days in diabetic rats after treatment with BMEE at 250 and 500 mg/kg dosage levels. Oral glucose tolerance test (OGTT), serum insulin levels, lipid profile and messenger RNA expression levels of Insulin receptor substrate 1 (IRS-1), Glucose transporter 2 (GLUT2), and Nuclear factor kappa light-chain enhancer of activated B cells (NFKβ) genes were determined. BMEE did not induce hypoglycemic effects in rats with normal blood glucose levels, but induced antidiabetic activities in the experimental type-2 diabetic rats. BMEE lowered FBG levels, increased oral glucose tolerance, increased insulin sensitization, and reduced insulin resistance. Treatment of diabetic rats with BMEE increased lipid metabolism and relatively higher expression levels of IRS-1 and GLUT2 genes, and led to reduced expression levels of NFKβ in the liver. Overall, this study reports that BMEE has potential as a nutraceutical to be utilized in the management of T2DM.

Comparing ADA and IDF diagnostic criteria for intermediate hyperglycaemia and diabetes in the SHiDS study.

This study aimed to assess the prevalence of IH and diabetes, as well as insulin secretion, insulin sensitivity, and related curve patterns in subjects with different glucose tolerance categories according to the diagnostic criteria established by the American Diabetes Association (ADA) and the more recently published International Diabetes Federation (IDF) guidelines. We used data of 5,387 adult participants from the Shanghai High-risk Diabetic Screen (SHiDS) study. All participants underwent a five-point 75 g oral glucose tolerance test (OGTT). Glycemic states were then classified according to the ADA/IDF diagnostic criteria, while OGTT-derived indices were employed to evaluate insulin secretion and sensitivity. Overall, 3,729 subjects were diagnosed consistently under ADA/IDF criteria; while 941 and 717 subjects exhibited inconsistencies in the diagnostic classification for diabetes and IH, respectively. Notably, all of these individuals with discrepant diagnoses displayed β-cell dysfunction and/or insulin resistance compared to the NGT/NGT group. The ADA criteria can identify individuals with elevated haemoglobinA1c (HbA1c) levels when the 1-hour plasma glucose (1-h PG) stay within the normal range, while the IDF criteria can identify subjects with impaired insulin sensitivity and secretion when fasting plasma glucose (FPG), 2-hour plasma glucose (2-h PG) and HbA1c values are in the normal range.