Baseline Oral Glucose Tolerance Test Research Articles

Impaired pancreatic beta-cell function after a single dose of oral iron: A before-and-after (pre-post) study.

Although in vitro and animal studies have shown that iron loading in pancreatic beta cells impairs insulin secretion, no human studies have documented the acute effects of oral iron on beta-cell insulin secretory capacity. In the present study, we determined beta-cell insulin secretory capacity at baseline and after a single oral dose of iron (ferrous sulphate, 120 mg elemental iron) in healthy male individuals. Fifteen healthy male volunteers underwent an oral glucose tolerance test (OGTT) to document baseline glucose tolerance and insulin secretion kinetics (baseline OGTT). One week later, the same subjects underwent a second OGTT, 2 h after an oral dose of ferrous sulphate (120 mg of elemental iron) (post-iron OGTT). Changes in disposition index, insulin secretion kinetics, glucose tolerance, insulin resistance, insulin clearance and iron-related parameters in serum were determined. Compared to baseline OGTT, the areas under the curve (AUC) for serum iron and transferrin saturation increased by 125% and 118%, respectively, in the post-iron OGTT. The disposition index decreased by 20% (p = 0.009) and the AUC for glucose concentrations increased by 5.7% (p < 0.001) during the post-iron OGTT. The insulin secretion rate was marginally lower during the first hour (-3.5%, p = 0.63), but became significantly higher during the second hour (22%, p = 0.005) of the post-iron OGTT. Insulin resistance and insulin clearance rate were not affected by iron intake. The decrease in disposition index and glucose tolerance observed after the oral dose of iron points to an acute iron-induced impairment in pancreatic beta-cell insulin secretory capacity.

Index60 Identifies Individuals at Appreciable Risk for Stage 3 Among an Autoantibody-Positive Population With Normal 2-Hour Glucose Levels: Implications for Current Staging Criteria of Type 1 Diabetes.

We assessed whether Index60, a composite measure of fasting C-peptide, 60-min C-peptide, and 60-min glucose, could improve the metabolic staging of type 1 diabetes for progression to clinical disease (stage 3) among autoantibody-positive (Ab+) individuals with normal 2-h glucose values (<140 mg/dL). We analyzed 3,058 Type 1 Diabetes TrialNet Pathway to Prevention participants with 2-h glucose <140 mg/dL and Index60 <1.00 values from baseline oral glucose tolerance tests. Characteristics associated with type 1 diabetes (younger age, greater Ab+, higher HLA DR3-DQ2/DR4-DQ8 prevalence, and lower C-peptide) were compared among four mutually exclusive groups: top 2-h glucose quartile only (HI-2HGLU), top Index60 quartile only (HI-IND60), both top quartiles (HI-BOTH), and neither top quartile (LO-BOTH). Additionally, within the 2-h glucose distribution of <140 mg/dL and separately within the Index60 <1.00 distribution, comparisons were made between those above or below the medians. HI-IND60 and HI-BOTH were younger, with greater frequency of more than two Ab+, and lower C-peptide levels, than either HI-2HGLU or LO-BOTH (all P < 0.001). The cumulative incidence for stage 3 was greater for HI-IND60 and HI-BOTH than for either HI-2HGLU or LO-BOTH (all P < 0.001). Those with Index60 values above the median were younger and had higher frequency of two or more Ab+ (P < 0.001) and DR3-DQ2/DR4-DQ8 prevalence (P < 0.001) and lower area under the curve (AUC) C-peptide levels (P < 0.001) than those below. Those above the 2-h glucose median had higher AUC C-peptide levels (P < 0.001), but otherwise did not differ from those below. Index60 identifies individuals with characteristics of type 1 diabetes at appreciable risk for progression who would otherwise be missed by 2-h glucose staging criteria.

TCF7L2 Genetic Variants Do Not Influence Insulin Sensitivity or Secretion Indices in Autoantibody-Positive Individuals at Risk for Type 1 Diabetes.

We aimed to test whether type 2 diabetes (T2D)-associated TCF7L2 genetic variants affect insulin sensitivity or secretion in autoantibody-positive relatives at risk for type 1 diabetes (T1D). We studied autoantibody-positive TrialNet Pathway to Prevention study participants (N = 1,061) (mean age 16.3 years) with TCF7L2 single nucleotide polymorphism (SNP) information and baseline oral glucose tolerance test (OGTT) to calculate indices of insulin sensitivity and secretion. With Bonferroni correction for multiple comparisons, P values < 0.0086 were considered statistically significant. None, one, and two T2D-linked TCF7L2 alleles were present in 48.1%, 43.9%, and 8.0% of the participants, respectively. Insulin sensitivity (as reflected by 1/fasting insulin [1/IF]) decreased with increasing BMI z score and was lower in Hispanics. Insulin secretion (as measured by 30-min C-peptide index) positively correlated with age and BMI z score. Oral disposition index was negatively correlated with age, BMI z score, and Hispanic ethnicity. None of the indices were associated with TCF7L2 SNPs. In multivariable analysis models with age, BMI z score, ethnicity, sex, and TCF7L2 alleles as independent variables, C-peptide index increased with age, while BMI z score was associated with higher insulin secretion (C-peptide index), lower insulin sensitivity (1/IF), and lower disposition index; there was no significant effect of TCF7L2 SNPs on any of these indices. When restricting the analyses to participants with a normal OGTT (n = 743; 70%), the results were similar. In nondiabetic autoantibody-positive individuals, TCF7L2 SNPs were not related to insulin sensitivity or secretion indices after accounting for BMI z score, age, sex, and ethnicity.

The Performance of Glycated Hemoglobin vs. Oral Glucose Tolerance Test in the Diagnosis of Glycemic Disorders among Women with Polycystic Ovary Syndrome in Southern Iraq

BACKGROUND: Obese women with polycystic ovary syndrome (PCOS) are at high risk for developing type 2 diabetes mellitus (T2DM). A baseline oral glucose tolerance test (2-h OGTT) is important to screen for dysglycemia in PCOS particularly those high risk women. Due to its advantages by fasting is not required and less day-to-day variability, glycated hemoglobin (HbA1c) might be a convenient screening tool. This study aimed to evaluate the performance of HbA1c vs. 2-h OGTT in the diagnosis of glycemic disorders in PCOS and to evaluate the correlation between glycemic disorders, insulin resistance (IR), and anthropometric measures.METHODS: One hundred and twenty nine women diagnosed with PCOS according to the Rotterdam 2003 criteria in Basrah were included in the study. All subjects were examined for weight, body mass index (BMI) and waist circumference (WC). Then they were tested for fasting glucose, 2-h OGTT, HbA1c, and fasting insulin to assess IR.RESULTS: The result of 2-h OGTT test showed that there were 21 subjects (16.1%) showed to have IGT. The result of HbA1c test showed that 25 subjects (19.4%) were diagonised with prediabetes. Meanwhile FPG test result showed that 34 subjects (26.4%) were having IFG. The HbA1c examination showed an underdetected the diagnosis of T2DM (0.8%) and an overdeteced diagnosis of prediabetes (19.4%) (p=0.021) and at HbA1c 5.55% (37.2 mmol/mol), the specificity was (74.3%) and sensitivity (56.5%) to discriminate normal from abnormal glucose status. Ninety nine women (76.7%) were either overweight or obese and most of them had IR (76.8%).CONCLUSION: Screening of glycemic disorders is crucial for PCOS by using 2-h OGTT regardless of risk factor and HbA1c seems to be an unsatisfactory screening tool to predict glycemic disorders in women with PCOS.KEYWORDS: PCOS, glycemic disorders, OGTT, HbA1c, insulin resistance, and prediabetes

The Performance of Glycated Hemoglobin Versus Oral Glucose Tolerance Test in the Diagnosis of Glycemic Disorders Among Women With Polycystic Ovary Syndrome in Southern Iraq

Background: Obese women with PCOS are at high risk for developing diabetes mellitus (T2DM). A baseline oral glucose tolerance test (2hrs-OGTT) annually is an important to screen for dysglycemia in women with PCOS particularly those with at least one risk factor. Due to its advantages by fasting is not required and less day-to-day variability during periods of stress or illness, glycated hemoglobin (HbA1c) might consider a convenient screening tool. This study aimed to evaluate the performance of HbA1c versus 2hrs-OGTT in the diagnosis of glycemic disorders in women with PCOS and to evaluate the correlation between glycemic disorders, insulin resistance (IR), and anthropometric measures. Patients and methods: One hundred and thirty women of a mean age 26.3 ± 6.85 year were diagnosed with PCOS according to Rotterdam 2003 criteria in Basrah, Southern Iraq. All women were examined for weight, BMI and waist circumference then they were sent for fasting plasma glucose (FPG), 2hrs-OGTT, HbA1c, and fasting insulin to assess IR. Results: By 2hrs-OGTT, impaired glucose tolerance and T2DM were diagnosed in 16.1% and 2.4% of women with PCOS respectively and 6.7% of lean women were prediabetes. HbA1c was underestimate the diagnosis of T2DM (0.8%) and overestimate prediabetes (20%) (p=0.011) and at HbA1c= 5.55%, the specificity was (74.3%) and sensitivity (56.5%) to discriminate normal from abnormal glucose status in women with PCOS (AUC: 0.645; 95% C.I.: 0.503–0.77; p = 0.03). One hundred women (76.9%) were either overweight or obese and most of them had IR (78%). Conclusion: screening of glycemic disorders is a crucial for PCOS by using 2hrs-OGTT regardless risk factor and HbA1c seems to be unsatisfactory screening tool to predict glycemic disorders in women with PCOS.

Combination therapy with pioglitazone/exenatide improves beta-cell function and produces superior glycaemic control compared with basal/bolus insulin in poorly controlled type 2 diabetes: A 3-year follow-up of the Qatar study.

To examine the long-term efficacy of thiazolidinedione plus a glucagon-like peptide-1 receptor agonist versus basal-bolus insulin on glycaemic control and beta-cell function in patients with poorly controlled type 2 diabetes (T2D) on metformin plus sulphonylurea. Three hundred and thirty-one patients with poorly controlled T2D were recruited over 3 years and were followed for an additional year. Subjects received a 75 g oral glucose tolerance test (OGTT) at baseline and at study end. After completing the baseline OGTT, subjects were randomized to receive either pioglitazone plus weekly exenatide (combination therapy) or basal/bolus insulin (insulin therapy) to maintain an HbA1c of less than 7.0%. The primary outcome of the study was the difference in HbA1c at study end between the two treatment groups. Both therapies caused a robust decrease in HbA1c. However, combination therapy caused a greater decrement (-1.1%, P < .0001) than insulin therapy, and more subjects in the combination therapy group (86%) achieved the American Diabetes Association goal of glycaemic control (HbA1c < 7.0%) than those in the insulin therapy group (44%) (P < .0001). Both therapies improved insulin secretion. However, the improvement in insulin secretion with combination therapy was 2.5-fold greater (P < .001) than with insulin therapy (50%). Insulin therapy caused more weight gain and hypoglycaemia. Both combination therapy and insulin therapy effectively reduced HbA1c in poorly controlled T2D on multiple oral agents. However, combination therapy produced a greater improvement in insulin secretion and decrease in HbA1c with a lower risk of hypoglycaemia.

348-OR: Metabolic Phenotype of Autoantibody Positive (AbPos) Long-Term Nonprogressors (LTNPs) to Type 1 Diabetes (T1D)

Few studies have described the metabolic phenotype of AbPos individuals who remain T1D free for an extended period of time. We aimed to compare C-peptide and glucose (Glu) data from oral glucose tolerance tests (OGTTs) performed longitudinally in 646 AbPos TrialNet Pathway to Prevention (PTP) participants who remained T1D free for ≥5.0 yrs (LTNPs; mean follow-up: 7.8±2.3 yrs) versus 405 Rapid Progressor (RP) PTP participants who progressed to T1D within &amp;lt;2 yrs of study entry (mean follow-up 0.97±0.54 yrs) and 150 Ab negative (AbNeg) controls. At study entry, 48% of LTNPs were single AbPos and 52% were multiple AbPos; 45.8% of single AbPos LTNPs became multiple AbPos during follow-up. LTNPs were older (mean age 18.8 ± 14.1 yrs) compared to RPs (11.8 ± 9.3 yrs) and AbNeg individuals (16 ± 10 yrs) (p&amp;lt;0.001). LTNPS exhibited an intermediate metabolic phenotype, with age and BMIZ-adjusted C-peptide area under the curve (AUC) and 30-0 min C-peptide values that were lower than AbNegs but higher than RPs (p&amp;lt;0.001), and Index60 levels (a composite of glucose and C-peptide values from OGTTs) that were higher than AbNegs but lower than RPs (p&amp;lt;0.001). Longitudinal trends in LTNPs were analyzed using fitted linear mixed models. Multiple AbPos LTNPs had higher Glu AUC (p=0.01) and Index60 values (p=0.032) compared to single AbPos LTNPs. However within both AbPos groups, metabolic patterns were remarkably stable over extended follow-up. When measures were evaluated for non-linear interactions using a regression tree analysis, the combination of Index60&amp;lt;1.06 + Glu AUC&amp;lt;137.7 at baseline was associated with an odds ratio of 8.55 (p&amp;lt;0.001) of being a LTNP. These data suggest that, while β cell function is reduced in LTNPs at the time of AbPos identification, longitudinal Glu and C-peptide patterns are largely stable without evidence of a relapsing or remitting course. Baseline OGTT measures (here, Index 60 and Glu AUC) may be able to predict AbPos individuals with lower risk of progression to T1D. Disclosure C. Evans-Molina: Consultant; Self; Bristol-Myers Squibb. Z.I. Saeed: None. J. Sosenko: None. M.A. Atkinson: None. K.C. Herold: Consultant; Self; Provention Bio, Inc. H.M. Ismail: None. H. Elding Larsson: None. M. Lundgren: None. A. Moran: Research Support; Self; Abbott, Intrexon, JDRF, Medtronic, National Institute of Diabetes and Digestive and Kidney Diseases, Provention Bio, Inc. Other Relationship; Self; Novo Nordisk Inc. D.J. Moore: None. B.M. Nathan: None. J.P. Palmer: None. E.K. Sims: None. A. Steck: None. D.K. Wherrett: None. M.J. Redondo: None. Funding National Institutes of Health (U01107014, U01DK106993)

Safety, efficacy and pharmacokinetics of repeat subcutaneous dosing of avexitide (exendin 9-39) for treatment of post-bariatric hypoglycaemia.

To evaluate the safety, efficacy and pharmacokinetics of repeat dosing of two formulations of subcutaneous (SC) avexitide (exendin 9-39) in patients with post-bariatric hypoglycaemia (PBH). In this phase 2, multiple-ascending-dose study conducted at Stanford University, 19 women with PBH underwent a baseline oral glucose tolerance test (OGTT), with metabolic and symptomatic assessments. Fourteen were then sequentially assigned to receive one of four ascending-dose levels of twice-daily lyophilized (Lyo) avexitide by SC injection for 3 days. On the basis of safety, efficacy and tolerability, five additional participants then received a novel liquid formulation (Liq) of avexitide by SC injection at a fixed dose of 30 mg twice daily for 3 days. All 19 participants underwent a repeat OGTT on day 3 of dosing to quantify metabolic, symptomatic and pharmacokinetic responses. Treatment with Lyo avexitide reduced the magnitude of symptomatic hyperinsulinaemic hypoglycaemia at all dose levels, with dose-dependent improvements in glucose nadir, insulin peak and symptom score; doses ≥20 mg twice daily did not require glycaemic rescue (administered at glucose <2.8 mmol/L). Participants receiving Liq avexitide 30 mg twice daily did not require any glycaemic rescue, and on average achieved a 47% increase in glucose nadir, a 67% reduction in peak insulin, and a 47% reduction in overall symptom score. Equivalent doses of Liq versus Lyo avexitide yielded higher and more sustained plasma concentrations. Both formulations were well tolerated. In patients with PBH, twice-daily administration of SC avexitide effectively raised the glucose nadir and prevented severe hypoglycaemia requiring rescue intervention. Avexitide may represent a viable therapy for PBH.

Clusters of Glycemic Response to Oral Glucose Tolerance Tests Explain Multivariate Metabolic and Anthropometric Outcomes of Bariatric Surgery in Obese Patients.

Glycemic responses to bariatric surgery are highly heterogeneous among patients and defining response types remains challenging. Recently developed data-driven clustering methods have uncovered subtle pathophysiologically informative patterns among patients without diabetes. This study aimed to explain responses among patients with and without diabetes to bariatric surgery with clusters of glucose concentration during oral glucose tolerance tests (OGTTs). We assessed 30 parameters at baseline and at four subsequent follow-up visits over one year on 154 participants in the Bialystok Bariatric Surgery Study. We applied latent trajectory classification to OGTTs and multinomial regression and generalized linear mixed models to explain differential responses among clusters. OGTT trajectories created four clusters representing increasing dysglycemias that were discordant from standard diabetes diagnosis criteria. The baseline OGTT cluster increased the predictive power of regression models by over 31% and aided in correctly predicting more than 83% of diabetes remissions. Principal component analysis showed that the glucose homeostasis response primarily occurred as improved insulin sensitivity concomitant with improved the OGTT cluster. In sum, OGTT clustering explained multiple, correlated responses to metabolic surgery. The OGTT is an intuitive and easy-to-implement index of improvement that stratifies patients into response types, a vital first step in personalizing diabetic care in obese subjects.

Fructose Consumption Contributes to Hyperinsulinemia in Adolescents With Obesity Through a GLP-1-Mediated Mechanism.

The consumption of high-fructose beverages is associated with a higher risk for obesity and diabetes. Fructose can stimulate glucagon-like peptide 1 (GLP-1) secretion in lean adults, in the absence of any anorexic effect. We hypothesized that the ingestion of glucose and fructose may differentially stimulate GLP-1 and insulin response in lean adolescents and adolescents with obesity. We studied 14 lean adolescents [four females; 15.9 ± 1.6 years of age; body mass index (BMI), 21.8 ± 2.2 kg/m2] and 23 adolescents with obesity (five females; 15.1 ± 1.6 years of age; BMI, 34.5 ± 4.6 kg/m2). Participants underwent a baseline oral glucose tolerance test to determine their glucose tolerance and estimate insulin sensitivity and β-cell function [oral disposition index (oDIcpep)]. Eligible subjects received, in a double-blind, crossover design, 75 g of glucose or fructose. Plasma was obtained every 10 minutes for 60 minutes for the measures of glucose, insulin, and GLP-1 (radioimmunoassay) and glucose-dependent insulinotropic polypeptide (GIP; ELISA). Incremental glucose and hormone levels were compared between lean individuals and those with obesity by a linear mixed model. The relationship between GLP-1 increment and oDIcpep was evaluated by regression analysis. Following the fructose challenge, plasma glucose excursions were similar in both groups, yet the adolescents with obesity exhibited a greater insulin (P < 0.001) and GLP-1 (P < 0.001) increase than did their lean peers. Changes in GIP were similar in both groups. After glucose ingestion, the GLP-1 response (P < 0.001) was higher in the lean group. The GLP-1 increment during 60 minutes from fructose drink was correlated with a lower oDIcpep (r2 = 0.22, P = 0.009). Fructose, but not glucose, ingestion elicits a higher GLP-1 and insulin response in adolescents with obesity than in lean adolescents. Fructose consumption may contribute to the hyperinsulinemic phenotype of adolescent obesity through a GLP-1-mediated mechanism.

Aspartame Consumption for 12 Weeks Does Not Affect Glycemia, Appetite, or Body Weight of Healthy, Lean Adults in a Randomized Controlled Trial

BackgroundLow-calorie sweeteners are often used to moderate energy intake and postprandial glycemia, but some evidence indicates that they may exacerbate these aims. ObjectiveThe trial's primary aim was to assess the effect of daily aspartame ingestion for 12 wk on glycemia. Effects on appetite and body weight were secondary aims. MethodsOne hundred lean [body mass index (kg/m2): 18–25] adults aged 18–60 y were randomly assigned to consume 0, 350, or 1050 mg aspartame/d (ASP groups) in a beverage for 12 wk in a parallel-arm design. At baseline, body weight and composition were determined, a 240-min oral-glucose-tolerance test (OGTT) was administered, and measurements were made of appetite and selected hormones. Participants also collected a 24-h urine sample. During the intervention, the 0-mg/d ASP group consumed capsules containing 680 mg dextrose and 80 mg para-amino benzoic acid. For the 350-mg/d ASP group, the beverage contained 350 mg aspartame and the 1050-mg/d ASP group consumed the same beverage plus capsules containing 680 mg dextrose and 700 mg aspartame. Body weight, blood pressure, heart rate, and waist circumference were measured weekly. At weeks 4, 8, and 12, participants collected 24-h urine samples and kept appetite logs. Baseline measurements were repeated at week 12. ResultsWith the exception of the baseline OGTT glucose concentration at 60 min (and resulting area under the curve value), there were no group differences for glucose, insulin, resting leptin, glucagon-like peptide 1, or gastric inhibitory peptide at baseline or week 12. There also were no effects of aspartame ingestion on appetite, body weight, or body composition. Compliance with the beverage intervention was ∼95%. ConclusionAspartame ingested at 2 doses for 12 wk had no effect on glycemia, appetite, or body weight among healthy, lean adults. These data do not support the view that aspartame is problematic for the management of glycemia, appetite, or body weight. This trial was registered at www.clinicaltrials.gov as NCT02999321.

Effect of one time high dose "stoss therapy" of vitamin D on glucose homeostasis in high risk obese adolescents.

To study the effect of using a one time high dose "stoss therapy" of vitamin D2 (ergocalciferol: VD2) on indices of insulin sensitivity {whole body sensitivity index: WBISI} and secretion {insulinogenic index: IGI} measured during an oral glucose tolerance test (OGTT) in obese adolescents with VDD (25 OHD; serum metabolite of vit D: < 30 ng/dL). In a randomized placebo controlled cross over design 20 obese adolescents with vitamin D deficiency (VDD) had baseline OGTT. Arm A received one time high dose 300,000 IU of ergocalciferol and Arm B received placebo. After 6 weeks the adolescents were reassigned to Arm A if they were in Arm B and vice versa. 25OHD, calcium, parathyroid hormone, comprehensive metabolic panel, urine calcium creatinine ratio were measured at each study visit. OGTTs to assess indices of sensitivity and secretion were done at baseline, 6 weeks and 12 weeks respectively. Adolescents were obese and insulin resistant (mean ± SD: mean age = 15.1 ± 1.9 years; BMI: 32.7 ± 9.8; homeostatic model of insulin resistance: HOMA-IR: 4.2 ± 2.8). Stoss therapy with VD2 increased 25OHD from baseline (16.7 ± 2.9 to 19.5 ± 4.5; p = 0.0029) when compared to the placebo. WBISI (2.8 ± 1.9) showed a trend towards improvement in Rx group (p = 0.0577) after adjustment for covariates. IGI (3 ± 2.2) showed an improvement in both Rx and placebo groups. Our study demonstrated that using a high dose of VD2 (300,000 IU) did not have any beneficial effect on insulin sensitivity (whole body sensitivity index {WBISI}) and secretory indices (insulinogenic index {IGI}) in obese adolescents. High dose "stoss therapy" of VD2 did not appear to have any beneficial effect on glucose homeostasis on obese adolescents.

Predicting progression to diabetes in islet autoantibody positive children

While full oral glucose tolerance test (OGTT) helps improve prediction, it requires intravenous access with 6 sample collections for glucose and C-peptide. The objective of this study was to explore less costly and less time-consuming options. All children being prospectively followed by the Diabetes Autoimmunity Study in the Young (DAISY) who had a complete baseline OGTT and at least one confirmed islet autoantibody (Ab+) were included in this study (n = 68). Of 68 Ab+ subjects with a baseline OGTT, 25 developed diabetes after a mean follow-up 5.7 yrs, at a mean age of 12.4 yrs. Univariate proportional hazards (PH) models suggested that age at seroconversion, number of Ab+, IA-2A levels, HbA1c and metabolic variables from the OGTT predicted progression to diabetes, while HLA DR3/4, BMI, levels of IAA or GADA did not. Five multivariate PH predictive models were similar (p = 0.32). All five models included age at seroconversion, number of Ab+, IA-2A levels and HbA1c, and in addition included: model 1 - 1 h glucose and 1 h C-peptide; model 2 - 2 h glucose and 2 h C-peptide; model 3 - glucose sum and C-peptide sum; model 4 - glucose AUC and C-peptide AUC; and model 5: index 60. A model containing age at seroconversion, number of Ab+, IA-2A levels, HbA1c, 1 h glucose and 1 h C-peptide was as predictive for type 1 diabetes progression as models including all sum or AUC values for glucose and C-peptide from full OGTT. The performance of this model should be confirmed in an independent population of Ab+ children.

Glucose Homeostasis and Effect of Chelation on β Cell Function in Children With β-Thalassemia Major.

To assess the prevalence of impaired glucose tolerance in β-thalassemia major and correlate it with chelation therapy. Sixty-seven subjects with β-thalassemia major, aged 1 to 20 years, were enrolled in our prospective cohort. Clinical details were recorded. Baseline oral glucose tolerance test, serum insulin, C peptide, and insulin resistance were measured. The biochemical profile was repeated after 6 months. The mean age of subjects was 7.43±4.48 years. Eight (11.9%) subjects had impaired fasting glucose, 7 (10.4%) had impaired glucose tolerance, and 1 (1.4%) subject had diabetes at baseline. Subjects with abnormal glucose profile had longer disease duration (95% confidence interval [CI] of difference=-6.64 to -0.68; P=0.019) and higher fasting blood glucose (95% CI of difference=-32.1 to -10.5; P=0.001) and serum ferritin (95% CI of difference=-219.8 to -3.4; P=0.001) than normoglycemic subjects. Insulin resistance and serum ferritin showed significant increase at 6 months (P<0.001 and P=0.001, respectively). Patients on deferiprone alone significantly improved glucose homeostasis on follow-up than those on desferrioxamine or combination therapy of desferrioxamine and deferiprone (P<0.05). Prolonged disease duration and higher serum ferritin adversely affects glucose homeostasis in thalassemic children. Deferiprone was the most effective chelator to improve glucose homeostasis in chronically transfused thalassemics.

Suppressed Adiponectin Levels and Increased Adiponectin Response to Oral Glucose Load in Lean Women with Severe Acne Normalizes after Isotretinoin Treatment

Background/Aim: Isotretinoin, the drug of choice for severe acne, might be associated with a decrease in insulin sensitivity. Adiponectin is an adipose tissue-derived protein that increases insulin sensitivity. In this study, we aimed to investigate adiponectin levels in postadolescent severe acne and the effect of isotretinoin on adiponectin levels. Methods: Participants included 18 female patients with severe acne and 18 healthy women matched for age and body mass index (BMI). Acne patients completed a 6-month isotretinoin treatment. Anthropometric measurements, serum adiponectin, lipids, fasting glucose, fasting insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were determined, and a standard 2-h oral glucose tolerance test (OGTT) was performed in healthy women once and in patients with acne before and after treatment. Results: At baseline, patients with acne had significantly lower serum adiponectin levels than controls. Isotretinoin treatment resulted in a significant increase in weight, BMI, and triglyceride and adiponectin levels. Glucose metabolism markers in patients with acne and controls were similar at baseline and did not change after treatment. Baseline OGTT in acne patients revealed an increased adiponectin response at 2 h, which was not present in healthy controls. Remarkably, this OGTT-induced adiponectin increment in acne patients was diminished after isotretinoin treatment. Conclusion: Adiponectin levels are differently regulated in women with severe acne and healthy controls in that circulating basal levels in patients are suppressed and show an increase in response to oral glucose load. Suppression of baseline adiponectin ameliorates after 6 months of isotretinoin treatment, reaching levels similar to those of healthy controls.

Cancerous glucose metabolism in lung cancer—evidence from exhaled breath analysis

Cancer cells prefer hyperglycolysis versus oxidative phosphorylation, even in the presence of oxygen. This phenomenon is used through the FDG-PET scans, and may affect the exhaled volatile signature. This study investigates the volatile signature in lung cancer (LC) before and after an oral glucose tolerance test (OGTT) to determine if tumor cells’ hyperglycolysis would affect the volatile signature. Blood glucose levels and exhaled breath samples were analyzed before the OGTT, and 90 min after, in both LC patients and controls. The volatile signature was measured by proton transfer reaction mass spectrometry (PTR-MS). Twenty-two LC patients (age 66.6 ± 12.7) with adenocarcinoma (n = 14), squamous (n = 6), small cell carcinoma (n = 2), and twenty-one controls (age 54.4 ± 13.7; 10 non-smokers and 11 smokers) were included. All LC patients showed a hyperglycolytic state in their FDG-PET scans. Both baseline and post OGTT volatile signatures discriminate between the groups. The OGTT has a minimal effect in LC (a decrease in m/z 54 by 39%, pv = 0.0499); whereas in the control group, five masses (m/z 64, 87,88, 142 and 161) changed by −13%, −49%, −40% and −29% and 46% respectively. To conclude, OGTT has a minimal effect on the VOC signature in LC patients, where a hyperglycolytic state already exists. In contrast, in the control group the OGTT has a profound effect in which induced hyperglycolysis significantly changed the VOC pattern. We hypothesized that a ceiling effect in cancerous patients is responsible for this discrepancy.

Neurolytic celiac plexus block enhances skeletal muscle insulin signaling and attenuates insulin resistance in GK rats.

Non-insulin-dependent diabetes mellitus (NIDDM) is associated with chronic inflammatory activity and disrupted insulin signaling, leading to insulin resistance (IR). The present study investigated the benefits of neurolytic celiac plexus block (NCPB) on IR in a rat NIDDM model. Goto-Kakizaki rats fed a high-fat, high-glucose diet to induce signs of NIDDM were randomly divided into NCPB and control groups; these received daily bilateral 0.5% lidocaine or 0.9% saline injections into the celiac plexus, respectively. Following 14 and 28 daily injections, rats were subject to oral glucose tolerance tests (OGTTs) or sacrificed for the analysis of serum free fatty acids (FFAs), serum inflammatory cytokines and skeletal muscle insulin signaling. Compared with controls, rats in the NCPB group demonstrated significantly (P<0.05) lower baseline, 60-min and 120-min OGTT values, lower 120-min serum insulin, lower IR [higher insulin sensitivity index (ISI1) and lower ISI2) and lower serum FFAs, tumor necrosis factor-α, interleukin (IL)-1β and IL-6. Conversely, NCPB rats exhibited higher basal and insulin-stimulated skeletal muscle glucose uptake and higher skeletal muscle insulin receptor substrate-1 (IRS-1) and glucose transporter type 4 expression. There were no differences between the groups in insulin receptor β (Rβ) or Akt expression; however Rβ-Y1162/Y1163 and Akt-S473 phosphorylation levels were higher and IRS-1-S307 phosphorylation were lower in NCPB rats than in the controls. These results indicate that NCPB improved insulin signaling and reduced IR, possibly by inhibiting inflammatory cytokine release.

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

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

American Association Of Clinical Endocrinologists, American College Of Endocrinology, And Androgen Excess And Pcos Society Disease State Clinical Review: Guide To The Best Practices In The Evaluation And Treatment Of Polycystic Ovary Syndrome - Part 2

Polycystic ovary syndrome (PCOS) is recognized as the most common endocrine disorder of reproductive-aged women around the world. This document, produced by the collaboration of the American Association of Clinical Endocrinologists and the Androgen Excess Society aims to highlight the most important clinical issues confronting physicians and their patients with PCOS. It is a summary of current best practices in 2014. Insulin resistance is believed to play an intrinsic role in the pathogenesis of PCOS. The mechanism by which insulin resistance or insulin give rise to oligomenorrhea and hyperandrogenemia, however, is unclear. Hyperinsulinemic-euglycemic clamp studies have shown that both obese and lean women with PCOS have some degree of insulin resistance. Insulin resistance is implicated in the ovulatory dysfunction of PCOS by disrupting the hypothalamic-pituitary-ovarian axis. Given the association with insulin resistance, all women with PCOS require evaluation for the risk of metabolic syndrome (MetS) and its components, including type 2 diabetes, hypertension, hyperlipidemia, and the possible risk of clinical events, including acute myocardial infarction and stroke. Obese women with PCOS are at increased risk for MetS with impaired glucose tolerance (IGT; 31 to 35%) and type 2 diabetes mellitus (T2DM; 7.5 to 10%). Rates of progression from normal glucose tolerance to IGT, and in turn to T2DM, may be as high as 5 to 15% within 3 years. Data suggest the need for baseline oral glucose tolerance test every 1 to 2 years based on family history of T2DM as well as body mass index (BMI) and yearly in women with IGT. Compared with BMI- and age-matched controls, young, lean PCOS women have lower high-density lipoprotein (HDL) size, higher very-low-density lipoprotein particle number, higher low-density lipoprotein (LDL) particle number, and borderline lower LDL size. Statins have been shown to lower testosterone levels either alone or in combination with oral contraceptives (OCPs) but have not shown improvement in menses, spontaneous ovulation, hirsutism, or acne. Statins reduce total and LDL cholesterol but have no effect on HDL, C-reactive protein, fasting insulin, or homeostasis model assessment of insulin resistance in PCOS women, in contrast to the general population. There have been no long-term studies of statins on clinical cardiac outcomes in women with PCOS. Coronary calcification is more prevalent and more severe in PCOS than in controls. In women under 60 years of age undergoing coronary angiography, the presence of polycystic ovaries on sonography has been associated with more arterial segments with >50% stenosis, but the relationship between PCOS and actual cardiovascular events remains unclear. Therapies for PCOS are varied in their effects and targets and include both nonpharmacologic as well as pharmacologic approaches. Weight loss is the primary therapy in PCOS--reduction in weight of as little as 5% can restore regular menses and improve response to ovulation- inducing and fertility medications. Metformin in premenopausal PCOS women has been associated with a reduction in features of MetS. Clamp studies using ethinyl estradiol/drosperinone combination failed to reveal evidence of an increase in either peripheral or hepatic insulin resistance. Subjects with PCOS have a 1.5-times higher baseline risk of venous thromboembolic disease and a 3.7-fold greater effect with OCP use compared with non-PCOS subjects. There is currently no genetic test to screen for or diagnose PCOS, and there is no test to assist in the choice of treatment strategies. Persistent bleeding should always be investigated for pregnancy and/or uterine pathology--including transvaginal ultrasound exam and endometrial biopsy--in women with PCOS. PCOS women can have difficulty conceiving. Those who become pregnant are at risk for gestational diabetes (which should be evaluated and managed appropriately) and the microvascular complications of diabetes. Assessment of a woman with PCOS for infertility involves evaluating for preconceptional issues that may affect response to therapy or lead to adverse pregnancy outcomes and evaluating the couple for other common infertility issues that may affect the choice of therapy, such as a semen analysis. Women with PCOS have multiple factors that may lead to an elevated risk of pregnancy, including a high prevalence of IGT--a clear risk factor for gestational diabetes--and MetS with hypertension, which increases the risk for pre-eclampsia and placental abruption. Women should be screened and treated for hypertension and diabetes prior to attempting conception. Women should be counseled about weight loss prior to attempting conception, although there are limited clinical trial data demonstrating a benefit to this recommendation. Treatment for women with PCOS and anovulatory infertility should begin with an oral agent such as clomiphene citrate or letrozole, an aromatase inhibitor.

Distribution of C-Peptide and Its Determinants in North American Children at Risk for Type 1 Diabetes

OBJECTIVETo determine basal and stimulated C-peptide percentiles in North American children and adolescents at risk for type 1 diabetes (T1D) and to examine factors associated with this distribution in the Diabetes Prevention Trial–Type 1 (DPT-1).RESEARCH DESIGN AND METHODSWe included 582 subjects aged 4–18 years at randomization in the DPT-1 trials. A 2-h oral glucose tolerance test (OGTT) was performed at baseline and every 6 months during the 5-year follow-up period. The percentile values of C-peptide after baseline OGTT were estimated according to age, BMI Z score (BMIZ), and/or sex categories. Conditional quantile regression was used to examine the relationship between C-peptide percentiles and various independent variables.RESULTSThe basal and stimulated C-peptide levels increased significantly as age and BMIZ increased (P < 0.05). Both age and BMIZ had a stronger impact on the upper quartile of C-peptide distributions than the lower quartile. Sex was only significantly associated with stimulated C-peptide. Higher stimulated C-peptide levels were generally observed in girls compared with boys at the same age and BMIZ (P < 0.05). HLA type and number of positive antibodies and antibody titers (islet cell antibody [ICA], insulin autoantibody, GAD65A, and ICA512A) were not significantly associated with C-peptide distribution after adjustment for age, BMIZ, and sex.CONCLUSIONSAge-, sex-, and BMIZ-specific C-peptide percentiles can be estimated for North American children and adolescents at risk for T1D. They can be used as an assessment tool that could impact the recommendations in T1D prevention trials.