Normal Glucose Tolerance Individuals Research Articles

Association between Transcription Factor 7-Like 2 Gene Polymorphisms rs7903146 and rs12255372 with the Risk of Diabetic Nephropathy among South Indian Population

Abstract Introduction: Transcription factor 7-like 2 (TCF7L2) gene has been associated with the genetic predisposition of type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN) in different populations. The study aimed to explore the correlation between rs7903146 and rs12255372 polymorphisms of TCF7L2 gene and DN among the South Indian population. Methods: Polymerase chain reaction (PCR)-based direct sequencing method and allele-specific PCR were used to determine the genotypes of TCF7L2 polymorphisms in 20 normal glucose tolerance (NGT) participants, 35 T2DM patients without DN and 35 T2DM patients with DN. The differences in genotype and allelic distribution between the study groups were analyzed by Chi-square test and odds ratio (OR) with 95% confidence interval (CI) which were used to indicate the relative risk of DN. Results: The distribution of TCF7L2 gene polymorphism rs7903146 prevalence was as follows: in the NGT group, CC, 65%; CT, 30%; TT, 5%; in the T2DM without DN group, CC, 25.71%; CT, 62.86%; TT, 11.43%; and in the T2DM with DN group, CC, 31.43%; CT, 60.0%; TT, 8.57%. The distribution of rs12255372 was as follows: in the NGT group, GG, 80%; GT, 15%; TT, 5%; in the T2DM without DN group, GG, 42.86%; GT, 41.46%; TT, 8.57%; and in the T2DM with DN group, GG, 48.57%; GT, 40%; TT, 5.71%. The T allele of rs7903146 polymorphism was associated with an increased risk of T2DM without DN (OR = 3.0; 95% CI = 1.21–7.437; P = 0.010) and T2DM with DN (OR = 2.51; 95% CI = 1.00–6.252; P = 0.04), and the T allele of rs12255372 polymorphism was also associated with increased risk of T2DM without DN (OR = 3.42; 95% CI = 1.18–9.902; P = 0.018) and not with T2DM with DN when compared with NGT individuals. Conclusion: In our study, the T allele of the rs7903146 single-nucleotide polymorphism in the TCF7L2 gene confers the risk of developing DN in diabetes patients, but the T allele of the rs12255372 polymorphism in the TCF7L2 gene is associated with T2DM and its association with DN is arbitrated through T2DM.

Differential effect of gastric bypass versus sleeve gastrectomy on insulinotropic action of endogenous incretins.

Prandial hyperinsulinemia after Roux-en-Y gastric bypass surgery (GB), and to lesser degree after sleeve gastrectomy (SG), has been attributed to rapid glucose flux from the gut and increased insulinotropic gut hormones. However, β-cell sensitivity to exogenous incretin is reduced after GB. This study examines the effect of GB versus SG on prandial glycemia and β-cell response to increasing concentrations of endogenous incretins. Glucose kinetics, insulin secretion rate (ISR), and incretin responses to 50-g oral glucose ingestion were compared between ten nondiabetic participants with GB versus nine matched individuals with SG and seven nonoperated normal glucose tolerant control individuals (CN) with and without administration of 200 mg ofsitagliptin. Fasting glucose and hormonal levels were similar among three groups. Increasing plasma concentrations of endogenous incretins by two- to three-fold diminished prandial glycemia and increased β-cell secretion in all three groups (p < 0.05), but insulin secretion per insulin sensitivity (i.e., disposition index) was increased only in GB (p < 0.05 for interaction). However, plot of the slope of ISR (from premeal to peak values) versus plasma glucagon-like peptide-1 concentration was smaller after GB compared with SG and CN. After GB, increasing incretin activity augments prandial β-cell response whereas the β-cell sensitivity to increasing plasma concentrations of endogenous incretin is diminished.

Weight progression and adherence to weight gain target in women with vs. without gestational diabetes: a retrospective cohort study

BackgroundWeight management has been an important component of the service in obstetric care offered to pregnant women. Current gestational weight gain recommendations were primarily for the general obstetric population, raising concern about the applicability to women with gestational diabetes mellitus (GDM). We aimed to assess the difference in weight progression and adherence to the recommended gestational weight gain targets between women with gestational diabetes mellitus (GDM) and women with normal glucose tolerance (NGT).MethodsThis was a hospital-based retrospective study of 56,616 pregnant women (9,430 GDM women and 47,186 NGT women) from Guangzhou between 2017 and 2021. The average change in weight progression was estimated based on serial weight measurements throughout pregnancy, using a mixed effects model with a random intercept to account for repeated measures of the same individual.ResultsWomen with GDM gained less weight (12.07 [SD 5.20] kg) than women with NGT (14.04 [SD 5.04] kg) throughout pregnancy. Before OGTT, a small difference was observed in the average change in weight progression between the two groups (GDM, 0.44 kg/week vs. NGT, 0.45 kg/week, p < 0.001), however, this gap widened significantly after the test (0.34 vs. 0.50 kg/week, p < 0.001). GDM individuals were identified with an approximately 4-fold increased proportion of insufficient weight gain (41.1% vs. 10.4%) and a 2-fold decreased proportion of excessive weight gain (22.6% vs. 54.2%) compared to NGT individuals. These results were consistently observed across different BMI categories, including underweight (insufficient: 52.7% vs. 19.9%; excessive: 15.6% vs. 35.3%), normal weight (insufficient 38.2% vs. 7.4%; excessive: 22.2% vs. 57.3%), and overweight/obese (insufficient: 43.1% vs. 9.8%; excessive: 30.1% vs. 68.8%).ConclusionWeight progression varied significantly between GDM and NGT individuals, resulting in a substantial difference in identifying insufficient and excessive weight gain between the two groups under current gestational weight gain guidelines.

234-OR: Succinate Potentiates Insulin Secretion through SUCNR1

Here, we examined the role of succinate, a metabolite that acts by engaging the succinate receptor 1 (SUCNR1), in regulating insulin secretion by β-cells. We found that glucose increases SUCNR1 expression in β-cells and that activating SUCNR1 with either extracellular succinate or a synthetic agonist boosts glucose-stimulated insulin secretion through the Gq and PKC signaling pathways. Also, we identified that SUCNR1 is essential for preserving insulin secretion in a diet-induced insulin-resistance model. Mice with β-cell-specific SUCNR1 deficiency had impaired glucose tolerance and reduced insulin secretion when fed a high-fat diet, without changes in β-cell mass or insulin sensitivity. To investigate the physiological significance of succinate as a secretagogue in humans, we studied the potential connection between circulating succinate levels and β-cell function in response to oral and intravenous glucose challenges in a cohort of patients with impaired glucose tolerance (IGT). These patients were characterized by presenting hyperinsulinemia during both oral and intravenous glucose tests, compared to normal glucose tolerance (NGT) individuals. Moreover, succinate levels were elevated in IGT patients in response to these challenges compared to NGT patients, whereas circulating GLP-1 levels during the tests were not different between groups. Remarkably, we found that circulating succinate levels are positively correlated with insulin secretion potentiation during intravenous glucose administration, indicating that this system is activated by high glucose levels and partially regulated by the β-cell in an autocrine fashion. These findings suggest that succinate may act as a hormone, potentiating insulin secretion in humans through SUCNR1- a compensatory mechanism particularly relevant in the hyperinsulinemia elicited by insulin resistance. Our work sheds new light on the role of the succinate-SUCNR1 axis as a potential therapeutic target for improving insulin secretion in metabolic disorders. Disclosure J.Sabadell-basallote: None. J.J.Vendrell: None. S.Fernandez-veledo: None. B.D.Astiarraga: None. M.Ejarque: None. M.Repollés-de-dalmau: None. F.X.Sureda: None. D.F.De jesus: None. C.Núñez roa: None. A.Mari: Consultant; Eli Lilly and Company. R.Kulkarni: Advisory Panel; Novo Nordisk, Inversago, Biomea Fusion, Inc., REDD Pharma, Research Support; Inversago. Funding Spanish Ministry of Science and Innovation (SAF2015-65019-R, RTI2018-093919-B-100); Instituto de Salud Carlos III (FI18/00151, CP10/00438, CPII16/00008); Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CB07708/0012); Catalan Association of Diabetes (PV21039S)

Chronic physiologic hyperglycemia impairs insulin-mediated suppression of plasma glucagon concentration in healthy humans

Background and aimsHyperglucagonemia is a characteristic feature of type 2 diabetes mellitus (T2DM). We examined the effect of chronic (48–72 h) physiologic increase (+50 mg/dl) in plasma glucose concentration on suppression of plasma glucagon concentration by insulin and by hyperglycemia in normal glucose tolerance (NGT) individuals. Materials and methodsStudy One: 16 NGT subjects received OGTT and 3-step hyperinsulinemic (10, 20, 40 mU/m2·min) euglycemic clamp before and after 48 hour glucose infusion to increase plasma glucose by ~50 mg/dl. Study Two: 20 NGT subjects received OGTT and 2-step hyperglycemic (+125 and + 300 mg/dl) clamp before and after 72 hour glucose infusion. Plasma insulin, C-peptide and glucagon concentrations were measured during OGTT, euglycemic hyperinsulinemic and hyperglycemic clamps. Ratio of plasma glucagon/insulin was used as an index of insulin-mediated suppression of glucagon secretion. ResultsDuring all 3 insulin clamp steps (Study 1), plasma glucagon concentration was increased compared to baseline study, and plasma glucagon/insulin ratio was significantly reduced by 24 % (p < 0.05). The rate of insulin-stimulated glucose disposal was inversely correlated with plasma glucagon/insulin ratio (r = −0.44, p < 0.05) and with glucagon AUC (r = −0.48, p < 0.05). During the 2-step hyperglycemic clamp (Study 2) plasma glucagon was similar before and after 72 h of glucose infusion; however, glucagon/insulin ratio was significantly reduced (p < 0.05). Incremental area under plasma insulin curve during the first (r = −0.74, p < 0.001) and second (r = −0.85, p < 0.001) hyperglycemic clamp steps was strongly and inversely correlated with plasma glucagon/insulin ratio. ConclusionSustained (48–72 h) physiologic hyperglycemia (+50 mg/dl) caused whole body insulin resistance and impaired insulin-mediated suppression of glucagon secretion, suggesting a role for glucotoxicity in development of hyperglucagonemia in T2DM.

Association Between Different Parameters of Adipose Distribution and Transient Elastography-Assessed Hepatic Steatosis in American Adults with Diabetes, Prediabetes and Normal Glucose Tolerance.

To investigate the association between adipose distribution and hepatic steatosis in American adults and to assess whether this association varies among different blood glucose states. Data from the American National Health and Nutrition Examination Survey (NHANES) 2017-2018 were analyzed. The subjects were divided into three groups: diabetes, prediabetes and normal glucose tolerance (NGT). Hepatic steatosis was quantified by median controlled attenuation parameter (CAP), which was measured by ultrasound transient elastography. Total abdominal fat volume, visceral adipose tissue (VAT) volume, total percent fat, trunk percent fat, android percent fat and android to gynoid ratio (AGR) was measured by dual-energy X-ray absorptiometry (DXA). Data pertaining to 2986 participants (1581 with hepatic steatosis) were included in the analysis. In the NGT group, the proportion of S0 (<5% of the hepatocytes with fatty infiltration) was 58.9%, and 25.2% for S3 (≥66% of the hepatocytes with fatty infiltration). In contrast, the proportion of S0 was 11.1%, while S3 accounts for as high as 68.7% in the diabetes group. In the NGT group, all parameters of fat distribution revealed a positive relation with the occurrence of hepatic steatosis (p<0.05) except total percent fat (p=0.872) after adjusting for confounding factors. In the prediabetes group, VAT volume, trunk percent fat, android percent fat and AGR had significant influence on hepatic steatosis (p<0.05). As for diabetes, only AGR remained significantly correlated with hepatic steatosis (p=0.004). For NGT individuals, high level of total abdominal fat volume, VAT volume, trunk percent fat, android percent fat and AGR all can be used to predict hepatic steatosis. For diabetes, only AGR can predict hepatic steatosis among the surveyed parameters of adipose distribution.

Irisin as a predictor of bone metabolism in Han Chinese Young Men with pre-diabetic individuals

BackgroundIrisin is a novel myokine both in mice and humans, and it can also be secreted by adipose tissue and the liver in a small amounts. There are few studies on irisin and bone metabolism. The aim of this study was to assess the relationship between serum irisin levels and bone metabolism and analyze its related factors in Han young male with pre-diabetic individuals.MethodsThis cross-sectional study included 41 pre-diabetes and 45 normal glucose tolerance (NGT). Anthropometric measurements, including height, weight, waist circumference (WC), and bone mineral content (BMC), were performed. All patients underwent an oral glucose tolerance test (OGTT) after 8 h of fasting, and the levels of glucose, insulin, lipids, serum irisin and bone turnover markers were measured.ResultsThe levels of serum irisin (4.4 ± 1.4 vs. 6.3 ± 1.5 µg/mL), P1NP and OC were significantly lower and CTX was significantly higher in the pre-diabetes group (P < 0.05). BMC did not differ in the two groups (P > 0.05). Serum irisin levels negatively correlated with BMI (r =-0.325), FPG (r =-0.329), TG (r =-0.339) (P < 0.05) in NGT individuals. Serum irisin levels positively correlated with P1NP (r = 0.398), OC (r = 0.351), HDL-C (r = 0.432) and negatively correlated with FPG (r = -0.725), 2 h-PG (r = -0.360) (P < 0.05) in pre-diabetic individuals. Multiple regression analysis revealed that Serum irisin (β = 9.768, P = 0.025) and WC (β = -2.355, P = 0.002) were significant independent predictors for P1NP.ConclusionBone turnover markers were changed rather than bone mineral content in young men with pre-diabetes. In pre-diabetes individuals, serum irisin levels were reduced and close relationship with P1NP. Falling irisin levels may be a predictor of decreased bone formation in Han young men with pre-diabetes individuals.

Metabolic Syndrome Is Associated With Impaired Insulin-Stimulated Myocardial Glucose Metabolic Rate in Individuals With Type 2 Diabetes: A Cardiac Dynamic 18F-FDG-PET Study.

Metabolic syndrome is a condition characterized by a clustering of metabolic abnormalities associated with an increased risk of type 2 diabetes and cardiovascular disease. An impaired insulin-stimulated myocardial glucose metabolism has been shown to be a risk factor for the development of cardiovascular disease in patients with type 2 diabetes. Whether cardiac insulin resistance occurs in subjects with metabolic syndrome remains uncertain. To investigate this issue, we evaluated myocardial glucose metabolic rate using cardiac dynamic 18F-FDG-PET combined with euglycemic-hyperinsulinemic clamp in three groups: a group of normal glucose tolerant individuals without metabolic syndrome (n = 10), a group of individuals with type 2 diabetes and metabolic syndrome (n = 19), and a group of subjects with type 2 diabetes without metabolic syndrome (n = 6). After adjusting for age and gender, individuals with type 2 diabetes and metabolic syndrome exhibited a significant reduction in insulin-stimulated myocardial glucose metabolic rate (10.5 ± 9.04 μmol/min/100 g) as compared with both control subjects (32.9 ± 9.7 μmol/min/100 g; P < 0.0001) and subjects with type 2 diabetes without metabolic syndrome (25.15 ± 4.92 μmol/min/100 g; P = 0.01). Conversely, as compared with control subjects (13.01 ± 8.53 mg/min x Kg FFM), both diabetic individuals with metabolic syndrome (3.06 ± 1.7 mg/min × Kg FFM, P = 0.008) and those without metabolic syndrome (2.91 ± 1.54 mg/min × Kg FFM, P = 0.01) exhibited a significant reduction in whole-body insulin-stimulated glucose disposal, while no difference was observed between the 2 groups of subjects with type 2 diabetes with or without metabolic syndrome. Univariate correlations showed that myocardial glucose metabolism was positively correlated with insulin-stimulated glucose disposal (r = 0.488, P = 0.003), and negatively correlated with the presence of metabolic syndrome (r = −0.743, P < 0.0001) and with its individual components. In conclusion, our data suggest that an impaired myocardial glucose metabolism may represent an early cardio-metabolic defect in individuals with the coexistence of type 2 diabetes and metabolic syndrome, regardless of whole-body insulin resistance.

Variations in glycated haemoglobin with age among individuals with normal glucose tolerance: Implications for diagnosis and treatment-Results from the ICMR-INDIAB population-based study (INDIAB-12).

To report on glycated haemoglobin (HbA1c) values among individuals with normal glucose tolerance (NGT) at different age groups, using data acquired from a large national survey in India. Data on glycaemic parameters at different age groups were obtained from the Indian Council of Medical Research-INdia DIABetes (ICMR-INDIAB) study, in adults aged ≥ 20years representing all parts of India. Age-wise distribution of HbA1c was assessed among individuals with NGT (n = 14,222) confirmed by an oral glucose tolerance test using the World Health Organization (WHO) criteria. Results were validated in another large epidemiological study (n = 1077) conducted in Chennai, India. Among NGT individuals, HbA1c increased gradually with age from 5.16 ± 0.71% (33mmol/mol) in the age group of 20-29years to 5.49 ± 0.69% (37mmol/mol) in those aged 70 + years. In the validation study, conducted in another study population, HbA1c was 5.35 ± 0.43% (35mmol/mol) in age group of 20-29years and 5.74 ± 0.50% (39mmol/mol) in those aged 70 and above. In the INDIAB study, for every decadal increase in age, there is a 0.08% increase in HbA1c and this increase was more significant in females (females: 0.10% vs. males: 0.06%) and in urban (urban: 0.10% vs. rural: 0.08%) population. HbA1c levels increase steadily with age. This suggests that age-specific cutoffs be used while utilizing HbA1c to diagnose diabetes and prediabetes, so as to minimize the risk of overdiagnosis and unnecessary initiation of treatment in elderly people who could have physiological increase in HbA1c levels.

Circulating Ligands of the Receptor for Advanced Glycation End Products and the Soluble Form of the Receptor Modulate Cardiovascular Cell Apoptosis in Diabetes.

We determined whether plasma concentrations of the receptor for advanced glycation end products (RAGE) and the soluble (s) form of RAGE (sRAGE) in healthy individuals and patients with type 2 diabetes (T2D) modulate vascular remodeling. Healthy individuals and patients with T2D were divided into two age groups: young = <35 years old or middle-aged (36–64 years old) and stratified based on normal glucose tolerance (NGT), impaired (IGT), and T2D. Plasma titers of sRAGE, the RAGE ligands, AGEs, S100B, S100A1, S100A6, and the apoptotic marker Fas ligand Fas(L) were measured by enzyme-linked immunosorbent assay (ELISA). The apoptotic potential of the above RAGE ligands and sRAGE were assessed in cultured adult rat aortic smooth muscle cells (ASMC). In NGT individuals, aging increased the circulating levels of AGEs and S100B and decreased sRAGE, S100A1 and S100A6. Middle-aged patients with T2D presented higher levels of circulating S100B, AGEs and FasL, but lower levels of sRAGE, S100A1 and S100A6 than individuals with NGT or IGT. Treatment of ASMC with either AGEs or S100B at concentrations detected in T2D patients increased markers of inflammation and apoptosis. Responses attenuated by concomitant administration of sRAGE. In middle-aged patients with T2D, lower circulating plasma levels of sRAGE may limit decoy and exogenous trapping of deleterious pro-apoptotic/pro-inflammatory RAGE ligands AGEs and S100B, increasing the risk for diabetic complications.

Family history of diabetes determines the association of HOMA-IR with fasting and postprandial triglycerides in individuals with normal glucose tolerance

Individuals with family history of diabetes carry nearly double the risk of diabetes than those without. However, the mechanism for this increased risk of diabetes in them is not fully understood. To study fasting and postprandial triglyceride levels in individuals with normal glucose tolerance (NGT) who had family history of diabetes and to ascertain their association with insulin resistance. Fasting triglyceride levels and HOMA-IR were compared in 671 NGT individuals with and without a family history of diabetes. A standardized fat challenge test was also done in one tenth of individuals of each group and postprandial triglyceride responses were compared between them. Association of HOMA-IR with fasting and postprandial triglyceride levels was ascertained through pearson's coefficient of correlation. Individuals with family history of diabetes had significantly higher HOMA-IR (P<0.001) and significantly higher postprandial triglyceride AUC (P=0.04) after standardized fat meal despite having similar fasting triglyceride levels (P=0.51) as those without family history of diabetes. Fasting as well as postprandial triglyceride levels significantly correlated with HOMA-IR (r=0.35, P<0.001 and r=0.39, P=0.04) only in those with a positive family history of diabetes but not in those without. Triglyceride levels mediated the associations of BMI (Δ β=-0.053) and waist circumference (Δ β=-0.075) with HOMA-IR. Triglyceride levels, both in the fasting and the postprandial state are associated with insulin resistance in NGT individuals with a family history of diabetes but not in those without.

No detectable effect of a type 2 diabetes-associated TCF7L2 genotype on the incretin effect.

The T allele of TCF7L2 rs7903146 is a common genetic variant associated with type 2 diabetes (T2D), possibly by modulation of incretin action. In this study, we evaluated the effect of the TCF7L2 rs7903146 T allele on the incretin effect and other glucometabolic parameters in normal glucose tolerant individuals (NGT) and participants with T2D. The rs7903146 variant was genotyped in cohorts of 61 NGT individuals (23 were heterozygous (CT) or homozygous (TT) T allele carriers) and 43 participants with T2D (20 with CT/TT). Participants were previously examined by an oral glucose tolerance test (OGTT) and a subsequent isoglycemic intravenous glucose infusion (IIGI). The incretin effect was assessed by quantification of the difference in integrated beta cell secretory responses during the OGTT and IIGI. Glucose and hormonal levels were measured during experimental days, and from these, indices of beta cell function and insulin sensitivity were calculated. No genotype-specific differences in the incretin effect were observed in the NGT group (P = 0.70) or the T2D group (P = 0.68). NGT T allele carriers displayed diminished glucose-dependent insulinotropic polypeptide response during OGTT (P = 0.01) while T allele carriers with T2D were characterized by lower C-peptide AUC after OGTT (P = 0.04) and elevated glucose AUC after OGTT (P = 0.04). In conclusion, our findings do not exclude that this specific TCF7L2 variant increases the risk of developing T2D via diminished incretin effect, but genotype-related defects were not detectable in these cohorts.

Circulating Meteorin-like Levels in Patients with Type 2 Diabetes Mellitus: A Meta-Analysis.

Meteorin-like (Metrnl) is a newly identified adipokine implicated in the pathogenesis of type 2 diabetes mellitus (T2DM), yet data on the circulating levels of Metrnl in patients with T2DM are controversial. To derive a more precise estimation on circulating Metrnl levels in T2DM patients, we conducted this meta-analysis. The existing studies on the circulating levels of Metrnl in patients with T2DM published up to 16 January 2020 were comprehensively retrieved from PubMed, Web of Science, EMBASE, and The Cochrane library database. Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated using random-effects model. Heterogeneity was assessed and quantified by Cochrane's Q and I2 statistic. All statistical analyses were performed using Stata 12.0 software. Nine studies with 867 T2DM patients and 831 normal glucose tolerance (NGT) controls were included in the final analysis according to the inclusion criteria. No significant difference in circulating Metrnl levels was found between T2DM patients and NGT individuals (pooled SMD = -0.429, 95% CI = -1.077 to 0.219). Compared to controls, circulating Metrnl levels were significantly higher in the subgroups with BMI <25 kg/m2, using plasma sample and patient sample size ≥100, while circulating Metrnl levels were significantly lower in subgroups with age ≤50 years and homeostatic model assessment for insulin resistance (HOMA-IR) ≥4. This meta-analysis indicates no significant change in circulating Metrnl levels in T2DM patients. However, this result may be influenced by age, BMI, sample type, HOMA-IR and patients sample size. Further longitudinal studies are warranted to offer more insights into the relationship between Metrnl and T2DM.

Serum 25-hydroxyvitamin D concentration and its association with glucose intolerance in an indigenous population

Type 2 diabetes is a multifactorial disease resulting from diverse genetic and environmental factors as well as the interaction between them. Low levels of 25-hydroxyvitamin D [25(OH)D], an indicator of vitamin D status, have been associated with an increased risk of type 2 diabetes, but not consistently. Also, it remains to be determined if this association differs among ethnic groups. Therefore, we aimed to evaluate vitamin D status and its association with glucose intolerance in a Brazilian indigenous population, the Xavante Indians. The study population consisted of 819 full Xavante Indians (410 women), aged ≥18 years and living in two indigenous reserves located in Mato Grosso State, central region of Brazil. Clinical examination and anthropometrical measurements were made, blood samples were obtained for total cholesterol, HDL-cholesterol, triglycerides and 25(OH)D measurement. Fasting and 2-h post 75g oral glucose load capillary glucose was measured. Vitamin D status was defined by serum 25(OH)D levels: vitamin D sufficiency (25(OH)D: 30-100ng/mL), vitamin D insufficiency (25(OH)D: 20- <30ng/mL) and vitamin D deficiency (25(OH)D: < 20ng/mL). Multiple logistic regression was performed to identify independent associations between 25(OH)D levels and impaired glucose tolerance or diabetes mellitus. Analyses stratified by 25(OH)D levels shows that 65.5% of the population had vitamin D deficiency/insufficiency (25(OH)D<30ng/mL). 25(OH)D concentrations were lower in individuals with impaired glucose tolerance or diabetes mellitus than in normal glucose tolerant individuals. Multiple logistic regression analysis showed an inverse association between increments of 25(OH)D and presence of diabetes mellitus (OR per 1ng/mL increase in 25(OH)D: 0.97; 95% confidence interval: 0.95-0.99), or impaired glucose tolerance (OR per 1ng/mL increase in 25(OH)D: 0.87; 95% confidence interval: 0.85-0.89), in an age, sex, BMI and season of sampling-adjusted model. The present population-based study found a high prevalence of hypovitaminosis D among Xavante Indians. In this at-risk population of type 2 diabetes, a significant association of higher serum 25(OH)D with a decreased prevalence of diabetes mellitus and impaired glucose tolerance was observed.

Prediabetes uncovers differential gene expression at fasting and in response to oral glucose load in immune cells

Metabolic disorders including diabetes are associated with immune cell dysfunction. However, the effect of normal glucose metabolism or impairment thereof on immune cell gene expression is not well known. Hence, in this cross-sectional pilot study, we sought to determine the differences in gene expression in the peripheral blood mono-nuclear cells (PBMCs) of normal glucose tolerant (NGT) and prediabetic (PD) Asian Indian men, at fasting and in response to 75g oral glucose load. Illumina HT12 bead chip-based microarray was performed on PBMCs at fasting and 2-h post load conditions for NGT (N=6) and PD (N=9) subjects. Following normalization and due quality control of the raw data, differentially expressed genes (DEGs) under different conditions within and across the two groups were identified using GeneSpring GX V12.0 software. Paired and unpaired Student's t-tests were applied along with fold change cut-offs for appropriate comparisons. Validation of the microarray data was carried out through real-time qPCR analysis. Significantly regulated biological pathways were analyzed by employing DEGs and DAVID resource. Deconvolution of the DEGs between NGT and PD subjects at fasting was performed using CIBERSORT and genes involved in regulatory T-cell (Treg) function were further analyzed for biological significance. Glucose load specifically altered the expression of 112 genes in NGT and 356 genes in PD subjects. Biological significance analysis revealed transient up-regulation of innate and adaptive immune response related genes following oral glucose load in NGT individuals, which was not observed in PD subjects. Instead, in the PD group, glucose load led to an increase in the expression of pro-atherogenic and anti-angiogenic genes. Comparison of gene expression at fasting state in PD versus NGT revealed 21,707 differentially expressed genes. Biological significance analysis of the immune function related genes between these two groups (at fasting) revealed higher gene expression of members of the TLR signaling, MHC class II molecules, and T-cell receptor, chemotaxis and adhesion pathways in PD subjects. Expression of interferon-γ (IFN-γ) and TNFα was higher and that of type-1 interferons and TGF-β was lower at fasting state in PD subjects compared to NGT. Additionally, expression of multiple proteasome subunits and protein arginine methyl transferase genes (PRMTs) were higher and that of Treg specific genes was significantly distinct at fasting in PD subjects compared to NGT. Prediabetes uncovers constitutive TLR activation, enhanced IFN-γ signaling, and Treg dysfunction at fasting along with altered gene expression response to oral glucose load.

A Nutrigenetic Approach to Investigate the Relationship between Metabolic Traits and Vitamin D Status in an Asian Indian Population.

Studies in Asian Indians have examined the association of metabolic traits with vitamin D status. However, findings have been quite inconsistent. Hence, we aimed to explore the relationship between metabolic traits and 25-hydroxyvitamin D [25(OH)D] concentrations. We investigate whether this relationship was modified by lifestyle factors using a nutrigenetic approach in 545 Asian Indians randomly selected from the Chennai Urban Rural Epidemiology Study (219 normal glucose tolerant individuals, 151 with pre-diabetes and 175 individuals with type 2 diabetes). A metabolic genetic risk score (GRS) was developed using five common metabolic disease-related genetic variants. There was a significant interaction between metabolic GRS and carbohydrate intake (energy%) on 25(OH)D (Pinteraction = 0.047). Individuals consuming a low carbohydrate diet (≤62%) and those having lesser number of metabolic risk alleles (GRS ≤ 1) had significantly higher levels of 25(OH)D (p = 0.033). Conversely, individuals consuming a high carbohydrate diet despite having lesser number of risk alleles did not show a significant increase in 25(OH)D (p = 0.662). In summary, our findings show that individuals carrying a smaller number of metabolic risk alleles are likely to have higher 25(OH)D levels if they consume a low carbohydrate diet. These data support the current dietary carbohydrate recommendations of 50%–60% energy suggesting that reduced metabolic genetic risk increases 25(OH)D.

Elevated 1-h post-load plasma glucose levels in normal glucose tolerance children with obesity is associated with early carotid atherosclerosis

ContextEvidence suggests that the 1-h post-load plasma glucose (1-h PG) ≥155mg/dL during an oral glucose tolerance test (OGTT) predicts development of type 2 diabetes (T2DM) and associated complications, among adults with normal glucose tolerance (NGT), but relevant data on children is scarce. ObjectivesTo investigate whether NGT children with obesity whose 1-h PG is ≥155mg/dL have an increased carotid intima-media thickness (IMT) and exhibit non-alcoholic fatty liver disease (NAFLD) diagnosed by ultrasonography, as compared with NGT subjects with 1-h PG <155mg/dL and impaired glucose tolerance (IGT). MethodsCardio-metabolic profile, OGTT, measurements of carotid IMT and liver ultrasonography were analyzed in 171 non-diabetic children with obesity. Subjects were divided into 3 groups: NGT subjects with a 1-h PG <155mg/dL, NGT subjects with a 1-h PG ≥155mg/dL, and IGT subjects. ResultsAs compared with NGT individuals with a 1-h PG <155mg/dL, NGT individuals with a 1-h PG ≥155mg/dL exhibited higher carotid IMT (0.75±0.15mm vs. 0.68±0.15mm; p<0.05). No significant differences were observed in carotid IMT between IGT and NGT subjects with a 1-h PG ≥155mg/dL (0.75±0.18mm vs 0.75±0.15mm; p>0.05). Of the three glycemic parameters, 1-h and 2-h PG, but not fasting glucose, were significantly correlated with carotid IMT. There were no significant differences for increased risk of having NAFLD between the three groups. ConclusionsThese data suggest that a value of 1-h PG ≥155mg/dL in children and adolescents with obesity is as important as IGT with respect to cardiovascular risks.

Reduced Circulating Endothelial Progenitor Cells and Downregulated GTCPH I Pathway Related to Endothelial Dysfunction in Premenopausal Women with Isolated Impaired Glucose Tolerance.

Background Individuals at a prediabetic stage have had an augmented cardiovascular disease (CVD) risk and CVD-related mortality compared to normal glucose tolerance (NGT) individuals, which may be attributed to the impaired vascular endothelial repair capacity. In this study, circulating endothelial progenitor cells' (EPCs) number and activity were evaluated, and the underlying mechanisms in premenopausal women with impaired glucose regulation were explored. Methods Circulating EPCs' number and activity and flow-mediated dilation (FMD) were compared in premenopausal women with NGT, isolated impaired fasting glucose (i-IFG), or isolated impaired glucose tolerance (i-IGT). Plasma nitric oxide (NO), EPCs-secreted NO, and intracellular BH4 levels were also measured. The key proteins (Tie2, Akt, eNOS, and GTPCH I) in the guanosine triphosphate cyclohydrolase/tetrahydrobiopterin (GTPCH/BH4) pathway and Tie2/Akt/eNOS signaling pathway were evaluated in these women. Results It was observed that the i-IGT premenopausal women not i-IFG premenopausal women had a significant reduction in circulating EPCs' number and activity as well as reduced FMD when compared to NGT subjects. Plasma NO levels or EPCs-secreted NO also decreased only in i-IGT women. The expression of GTCPH I as well as intracellular BH4 levels declined in i-IGT women; however, the alternations of key proteins' expression in the Tie2/Akt/eNOS signaling pathway were not observed in either i-IGT or i-IFG women. Conclusions The endothelial repair capacity was impaired in i-IGT premenopausal women but was preserved in i-IFG counterparts. The underlying mechanism may be associated with the downregulated GTCPH I pathway and reduced NO productions.

The relationship of gestational weight gain and development of gestational diabetes mellitus

Objective: To assess the effect of gestational weight gain in women developing gestational diabetes mellitus (GDM). Methods: In this retrospective case control study, singleton mothers with GDM (n=51) were compared with a control group (n=153) matched for age (±2 years), parity, booking visit BMI (±2 kg/m2). They were reviewed at delivery to identify sociodemographic risk factors and treatment modality if they were found to have GDM. Maternal weight at booking visit, at the end of 1st trimester and at the time of glucose tolerance testing was extracted from maternity records. Total gestational weight gain, and rate of weight gain per week during 1st and 2nd trimesters were the primary outcome data. Results: Having a 1st degree relative with diabetes had a significant association for development of GDM. No significant difference was observed in total weight gain or 2nd trimester weight gain between case and controls. However, weight gain during 1st trimester was significantly higher among mothers diagnosed with GDM when compared with controls. This difference was most significant among normal and overweight BMI categories. Out of the GDM group, although the mean rate of weight gain was higher in the pharmacotherapy sub group, there was no statistical significance compared with the group who was only on Medical Nutrition Therapy. Conclusions and recommendations: Gestational weight gain during first trimester was significantly higher among patients with GDM who were in the normal and overweight BMI categories compared to normal glucose tolerant individuals. Mothers with excessive 1st trimester weight gain should be carefully followed up for development of GDM.

Circulating miR-103 family as potential biomarkers for type 2 diabetes through targeting CAV-1 and SFRP4.

MicroRNA-103 (miR-103) family plays important roles in regulating glucose homeostasis in type 2 diabetes mellitus (DM2). However, the underlying mechanisms remain poorly characterized. The objective of this study was to test the hypothesis that circulating miR-103a and miR-103b, which regulate CAV-1 and SFRP4, respectively, are novel biomarkers for diagnosis of DM2. We determined the predictive potential of circulating miR-103a and miR-103b in pre-DM subjects (pre-DM), noncomplicated diabetic subjects, and normal glucose-tolerance individuals (control) using bioinformatic analysis, qRT-PCR, luciferase assays, and ELISA assays. We found that both miR-103a and miR-103b had high complementarity and conservation, modulated reporter gene expression through seed sequences in the 3'UTRs of CAV-1 and SFRP4 mRNA, and negatively regulated their mRNA and protein levels, respectively. We also found that increased miR-103a and decreased miR-103a in plasma were significantly and negatively correlated with reduced CAV-1 levels and elevated SFRP4 levels in pre-DM and DM2, respectively, and were significantly associated with glucose metabolism, HbA1c levels, and other DM2 risk factors for progression from a normal individual to one with pre-DM. Furthermore, we demonstrated that the reciprocal changes in circulating miR-103a and miR-103b not only provided high sensitivity and specificity to differentiate the pre-DM population but also acted as biomarkers for predicting DM2 with high diagnostic value. These findings suggest that circulating miR-103a and miR-103b may serve as novel biomarkers for diagnosis of DM2, providing novel insight into the mechanisms underlying pre-DM.