Análisis comparativo de respuesta glicémica y de péptido C, tras la ingesta de estevia y D-tagatosa, según habitualidad de consumo de edulcorantes no nutritivos y preferencias alimentarias reportadas por mujeres con resistencia a la insulina / Comparative analysis of glicemic response and c peptide, after comsumption of stevia and d tagatosa, according to regular compsumtion of not nutritive sweeteners andnourish preferences reported by woman with insuline resistance

INTRODUCCIÓN: El consumo de edulcorantes no nutritivos (ENN) ha ido en aumento. A pesar de ello, se desconoce el efecto entre el consumo habitual de ENN y las preferencias alimentarias con parámetros bioquímicos en pacientes con resistencia a la insulina. OBJETIVO: Comparar la respuesta glicémica y de péptido C, según habitualidad de consumo de edulcorantes y preferencias alimentarias reportados por mujeres con resistencia a la insulina tras la ingesta de estevia y D-tagatosa. MÉTODOS: Treinta y tres mujeres con RI se sometieron a una encuesta de opción múltiple sobre preferencias alimentarias y ETCC modificada de edulcorantes. Aleatoriamente recibieron una precarga de control o experimental (estevia y D-tagatosa) donde se midió glicemia y péptido C en los tiempos -10, 30, 60, 90, 120, 180. RESULTADOS: Se encontró un ABC de péptido C más alto después de la ingesta de D-tagatosa (p = 0,02) en pacientes que prefieren alimentos ricos en proteínas en comparación con aquellos que prefieren alimentos ricos en grasas o en carbohidratos simples. Se observó un mayor ABC de péptido C (p = 0,04) para la prueba control en quienes prefieren el sabor salado y consumen menor cantidad de ENN, sin diferencias significativas entre quienes prefirieron sabor dulce. CONCLUSIONES: Al comparar las respuestas glicémicas e insulinémicas entre habitualidad de consumo de edulcorantes y preferencias alimentarias reportados por las pacientes tras la ingesta de agua, estevia y D-Tagatosa, no se obtuvieron diferencias significativas. Salvo en quienes preferían alimentos ricos en proteínas tras la ingesta de D- tagatosa y quienes preferían sabor salado con menor consumo habitual de ENN tras ingesta control.

INTRODUCTION: The consumption of non-nutritive sweeteners (NNS) has been increasing. Despite this, the effect between the habitual consumption of ENN and food preferences with biochemical parameters in patients with insulin resistance is unknown. OBJECTIVE: To compare the glycemic and C-peptide response, according to the habitual consumption of sweeteners and food preferences reported by women with insulin resistance after ingesting stevia and D-tagatose. METHODS: Thirty-three women with IR underwent a multiple choice survey on food preferences and modified ETCC for sweeteners. They randomly received a control or experimental preload (stevia and D-tagatose) where glycemia and peptide C were measured at times -10, 30, 60, 90, 120, 180. RESULTS: A higher C-peptide AUC was found after ingestion of D-tagatose (p = 0.02) in patients who prefer foods rich in protein compared to those who prefer foods rich in fat or simple carbohydrates. A higher AUC of peptide C (p = 0.04) is performed for the control test in those who prefer a salty taste and consume a lower amount of ENN, without significant differences between those who prefer a sweet taste. CONCLUSION: When comparing the glycerol and insulin responses between the habitual consumption of sweeteners and the food preferences reported by the patients after the ingestion of water, stevia and D-Tagatose, no significant differences were obtained. Except in those who prefer foods rich in protein after ingesting D-tagatose and those who prefer salty taste with less habitual consumption of NNS after control intake.

The effect of acute dual SGLT1/SGLT2 inhibition on incretin release and glucose metabolism after gastric bypass surgery.

Enhanced meal-related enteroendocrine secretion, particularly of glucagon-like peptide-1 (GLP-1), contributes to weight-loss and improved glycemia after Roux-en-Y gastric bypass (RYGB). Dietary glucose drives GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) secretion postoperatively. Understanding how glucose triggers incretin secretion following RYGB could lead to new treatments of diabetes and obesity. In vitro, incretin release depends on glucose absorption via sodium-glucose cotransporter 1 (SGLT1). We investigated the importance of SGLT1/SGLT2 for enteropancreatic hormone concentrations and glucose metabolism after RYGB in a randomized, controlled, crossover study. Ten RYGB-operated patients ingested 50 g of oral glucose with and without acute pretreatment with 600 mg of the SGLT1/SGLT2-inhibitor canagliflozin. Paracetamol and 3-O-methyl-d-glucopyranose (3-OMG) were added to the glucose drink to evaluate rates of intestinal entry and absorption of glucose, respectively. Blood samples were collected for 4 h. The primary outcome was 4-h plasma GLP-1 (incremental area-under the curve, iAUC). Secondary outcomes included glucose, GIP, insulin, and glucagon. Canagliflozin delayed glucose absorption (time-to-peak 3-OMG: 50 vs. 132 min, P < 0.01) but did not reduce iAUC GLP-1 (6,067 vs. 7,273·min·pmol-1·L-1, P = 0.23), although peak GLP-1 concentrations were lowered (-28%, P = 0.03). Canagliflozin reduced GIP (iAUC -28%, P = 0.01; peak concentrations -57%, P < 0.01), insulin, and glucose excursions, whereas plasma glucagon (AUC 3,216 vs. 4,160 min·pmol·L-1, P = 0.02) and amino acids were increased. In conclusion, acute SGLT1/SGLT2-inhibition during glucose ingestion did not reduce 4-h plasma GLP-1 responses in RYGB-patients but attenuated the early rise in GLP-1, GIP, and insulin, whereas late glucagon concentrations were increased. The results suggest that SGLT1-mediated glucose absorption contributes to incretin hormone secretion after RYGB.

Analysis of Metal Effects on C-Peptide Structure and Internalization.

The connecting peptide (C-peptide) has received increased attention for its potential therapeutic effects in ameliorating illnesses such as kidney disease and diabetes. Although the mechanism of C-peptide signaling remains elusive, evidence supports its internalization and intracellular function. Emerging research is uncovering the diverse biological roles metals play in controlling and affecting the function of bioactive peptides. The work presented herein investigates interactions between C-peptide and first-row d-block transition metals, as well as their effects on C-peptide internalization into cells. Through spectroscopic techniques, it is demonstrated that CrIII , CuII , and ZnII bind to C-peptide with differing stoichiometries and biologically relevant affinities. In addition, metal binding elicits both subtle changes in secondary structure and inhibits adoption of an α-helical character in environments where the dielectric constants are reduced. This study shows how metal ions can modulate peptide hormone activity through subtle structural changes to disrupt cellular uptake.

The association of calcium channel blockers with ß-cell function in type 2 diabetic patients: A cross-sectional study.

Type 2 diabetes mellitus (T2DM) patients are often accompanied with hypertension. However, the association of antihypertensive drugs with ß-cell function has not been well studied. To investigate this question, the authors performed a cross-sectional study involving 882 hypertensive T2DM patients. To assess ß-cell function, patients were given 75g glucose orally and C-peptide levels before and 1, 2, and 3 hours after glucose intake were measured. Homa-ß was computed by Homeostasis Model Assessment model to evaluate ß-cell function using fasting C-peptide and glucose levels in the plasma. Multivariable-adjusted analysis was performed to evaluate the association of antihypertensive drugs with C-peptide levels, HbA1c, and Homa-ß. Among 882 hypertensive patients, 547 (62.0%) received antihypertensive treatment. Multivariate-adjusted analysis demonstrated that use of calcium channel blockers (CCBs) was negatively associated with HbA1c levels (CCBs: 0.95 [95% CI: 0.92-0.98], P = 0.002). Our data further illustrated that the C-peptide levels before and 1, 2, and 3 hours of OGTT were 1.10-, 1.18-, 1.19-, and 1.15-fold increase in T2DM patients taking CCBs (P = 0.084 for fasting C-peptide levels; P ≤ 0.024 for C-peptide levels at 1, 2, and 3 hours after OGTT) in comparison with non-CCB users. Nevertheless, usage of any other antihypertensive drugs did neither associated with HbA1c nor associated with C-peptide levels (P ≥ 0.11). In conclusion, CCB treatment was negatively associated with HbA1c levels but positively associated with ß-cell function in hypertensive T2DM patients, implying that CCBs could be considered to treat hypertensive T2DM patients with reduced ß-cell function.

Islet Hormone and Incretin Secretion in Cystic Fibrosis after Four Months of Ivacaftor Therapy.

RATIONALE: Diabetes is associated with worse cystic fibrosis (CF) outcomes. The CFTR potentiator ivacaftor is suggested to improve glucose homeostasis in individuals with CF. OBJECTIVES: To test the hypothesis that clinically indicated ivacaftor would be associated with improvements in glucose tolerance and insulin and incretin secretion. METHODS: Oral glucose tolerance tests, mixed-meal tolerance tests, and glucose-potentiated arginine tests were compared preivacaftor initiation and 16 weeks postivacaftor initiation in CF participants with at least one CFTR gating or conductance mutation. Meal-related 30-minute (early phase) and 180-minute incremental area under the curves were calculated as responses for glucose, insulin, C-peptide, and incretin hormones; glucagon-like peptide-1; and glucose-dependent insulinotropic polypeptide. First-phase insulin secretion, glucose potentiation of arginine-induced insulin secretion, and disposition index were characterized by glucose-potentiated arginine stimulation tests. MEASUREMENTS AND MAIN RESULTS: Twelve subjects completed the study: six male/six female; seven normal/five abnormal glucose tolerance (oral glucose tolerance test 1-h glucose ≥155 and 2-h glucose <200 mg/dl); of median (minimum-maximum) age (13.8 yr [6.0-42.0]), body mass index-Z of 0.66 (-2.4 to 1.9), and FEV1% predicted of 102 (39-122). Glucose tolerance normalized in one abnormal glucose tolerance subject. Ivacaftor treatment did not alter meal responses except for an increase in early phase C-peptide (P = 0.04). First-phase (P = 0.001) and glucose potentiation of arginine-induced (P = 0.027) insulin secretion assessed by acute C-peptide responses improved after ivacaftor treatment. Consistent with an effect on ß-cell function, the disposition index relating the amount of insulin secreted for insulin sensitivity also improved (P = 0.04). CONCLUSIONS: Insulin secretion improved following 4 months of clinically indicated ivacaftor therapy in this relatively young group of patients with CF with normal to mildly impaired glucose tolerance, whereas incretin secretion remained unchanged.

One-year follow-up on liraglutide treatment for prediabetes and overweight/obesity in clozapine- or olanzapine-treated patients.

OBJECTIVE: Treatment with most antipsychotics is associated with an increased risk of weight gain and metabolic disturbances. In a randomized trial, we previously demonstrated that 16 weeks of glucagon-like peptide-1 receptor agonist liraglutide treatment vs. placebo significantly reduced glucometabolic disturbances and body weight in prediabetic, overweight/obese schizophrenia-spectrum disorder patients treated with clozapine or olanzapine. The aim of this study was to investigate whether the beneficial effects of the 16-week intervention were sustained beyond the intervention period. METHOD: One year after completion of the intervention, we investigated changes in body weight, fasting glucose, glycated hemoglobin, C-peptide, and lipids comparing 1-year follow-up levels to end of treatment (week 16) and baseline (week 0) levels. RESULTS: From end of treatment to the 1-year follow-up, body weight had increased in the liraglutide-treated group. However, compared to baseline levels, the placebo-subtracted body weight loss remained significantly reduced (-3.8 kg, 95% CI: -7.3 to -0.2, P = 0.04). Fasting glucose, glycated hemoglobin, C-peptide, and lipids had each returned to baseline levels 1 year after stopping liraglutide. CONCLUSION: The body weight reduction during 16 weeks of liraglutide treatment was partially sustained 1 year after the intervention was completed. However, the improvements in other metabolic parameters returned to baseline levels.

Ethnic differences in insulin secretory function between black African and white European men with early type 2 diabetes.

AIM: To test the hypothesis that men of black (West) African ethnicity (black African men [BAM]) with early type 2 diabetes (T2D) would have greater insulin secretory deficits compared with white European men (WEM), following prediabetic hypersecretion. METHODS: In 19 BAM and 15 WEM, matched for age, body mass index and duration of diabetes, we assessed and modelled insulin secretory responses to hyperglycaemia stimulated intravenously (hyperglycaemic clamp) and orally (meal tolerance test). RESULTS: With similar post-challenge glucose responses, BAM had lower second-phase C-peptide responses to intravenous glucose (BAM 70.6 vs WEM 115.1 nmol/L/min [ratio of geometric mean 0.55, 95% confidence interval {CI} 0.37, 0.83]; P = .006) and to oral glucose (BAM 65.4 vs WEM 88.5 nmol/L/min [mean difference -23.2, 95% CI -40.0, -6.3]; P = .009). Peripheral insulin response in BAM to oral glucose was preserved (BAM 47.4 vs WEM 59.4 nmol/L/min [ratio of geometric mean 0.89, 95% CI 0.59, 1.35]; P = .566), with relative reductions in insulin clearance (BAM 506.2 vs WEM 630.1 mL/m2 BSA/min [mean difference -123.9, 95% CI -270.5, 22.6]; P = .095), associated with enhanced incretin responses (gastric inhibitory polypeptide incremental area under the curve: BAM 46.8 vs WEM 33.9 µg/L/min [mean difference 12.9, 95% CI 2.1, 23.7]; P = .021). CONCLUSIONS: In early T2D, BAM had significantly lower insulin secretory responses to intravenous and oral stimulation than WEM. Lower insulin clearance, potentially driven by increased incretin responses, may act to preserve peripheral insulin concentrations. Tailoring early management strategies to reflect distinct ethnic-specific pathophysiology may improve outcomes in this high-risk population.

Efficacy and safety of canagliflozin as add-on therapy to teneligliptin in Japanese patients with type 2 diabetes mellitus: Results of a 24-week, randomized, double-blind, placebo-controlled trial.

AIMS: To investigate efficacy and safety of the sodium-glucose co-transporter 2 (SGLT2) inhibitor canagliflozin administered as add-on therapy to the dipeptidyl peptidase-4 (DPP-4) inhibitor teneligliptin in patients with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: We conducted a multicentre, randomized, double-blind, placebo-controlled, phase 3 clinical trial in Japanese patients with T2DM who had inadequate glycaemic control with teneligliptin. Patients were randomized to receive teneligliptin 20 mg plus either canagliflozin 100 mg (T + C, n = 70) or placebo (T + P, n = 68) once daily. The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline to week 24. Other endpoints included changes in fasting plasma glucose, body weight, proinsulin/C-peptide ratio, homeostatic model assessment 2-%B and adverse events. Patients also underwent mixed-meal tolerance tests. RESULTS: The difference between the T + C and T + P groups for HbA1c change from baseline to week 24 was -0.88% (least-squares mean, P < .001). Fasting plasma glucose, body weight and the proinsulin/C-peptide ratio were significantly lower in the T + C group than in the T + P group. Homeostatic model assessment 2-%B improved with T + C compared with T + P. The T + C group exhibited a decrease in the 2-hour postprandial plasma glucose and plasma glucose area under the curve (AUC)0-2h in a mixed-meal tolerance test. No significant between-group differences were observed for C-peptide AUC0-2h or glucagon AUC0-2h after meals. Incidences of adverse events were 60.0% and 47.1% in the T + C and T + P groups, respectively. No hypoglycaemia was observed. CONCLUSIONS: Canagliflozin administered as add-on therapy to teneligliptin was effective and well tolerated in Japanese T2DM patients.

Neu5Gc and α1-3 GAL Xenoantigen Knockout Does Not Affect Glycemia Homeostasis and Insulin Secretion in Pigs.

Xenocell therapy from neonate or adult pig pancreatic islets is one of the most promising alternatives to allograft in type 1 diabetes for addressing organ shortage. In humans, however, natural and elicited antibodies specific for pig xenoantigens, α-(1,3)-galactose (GAL) and N-glycolylneuraminic acid (Neu5Gc), are likely to significantly contribute to xenoislet rejection. We obtained double-knockout (DKO) pigs lacking GAL and Neu5Gc. Because Neu5Gc-/- mice exhibit glycemic dysregulations and pancreatic ß-cell dysfunctions, we evaluated islet function and glucose metabolism regulation in DKO pigs. Isolation of islets from neonate piglets yielded identical islet equivalent quantities to quantities obtained from control wild-type pigs. In contrast to wild-type islets, DKO islets did not induce anti-Neu5Gc antibody when grafted in cytidine monophosphate-N-acetylneuraminic acid hydroxylase KO mice and exhibited in vitro normal insulin secretion stimulated by glucose and theophylline. Adult DKO pancreata showed no histological abnormalities, and immunostaining of insulin and glucagon was similar to that from wild-type pancreata. Blood glucose, insulin, C-peptide, the insulin-to-glucagon ratio, and HOMA-insulin resistance in fasted adult DKO pigs and blood glucose and C-peptide changes after intravenous glucose or insulin administration were similar to wild-type pigs. This first evaluation of glucose homeostasis in DKO pigs for two major xenoantigens paves the way to their use in (pre)clinical studies.

Targeting orphan G protein-coupled receptors for the treatment of diabetes and its complications: C-peptide and GPR146.

G protein-coupled receptors (GPCRs) are the most abundant receptor family encoded by the human genome and are the targets of a high percentage of drugs currently in use or in clinical trials for the treatment of diseases such as diabetes and its associated complications. Thus, orphan GPCRs, for which the ligand is unknown, represent an important untapped source of therapeutic potential for the treatment of many diseases. We have identified the previously orphan GPCR, GPR146, as the putative receptor of proinsulin C-peptide, which may prove to be an effective treatment for diabetes-associated complications. For example, we have found a potential role of C-peptide and GPR146 in regulating the function of the retinal pigment epithelium, a monolayer of cells in the retina that serves as part of the blood-retinal barrier and is disrupted in diabetic macular oedema. However, C-peptide signalling in this cell type appears to depend at least in part on extracellular glucose concentration and its interaction with insulin. In this review, we discuss the therapeutic potential of orphan GPCRs with a special focus on C-peptide and GPR146, including past and current strategies used to 'deorphanize' this diverse family of receptors, past successes and the inherent difficulties of this process.

Antiinflammatory and ROS Suppressive Effects of the Addition of Fiber to a High-Fat High-Calorie Meal.

Background: Fiber intake is associated with a reduction in the occurrence of cardiovascular events and diabetes. Objective: To investigate whether the addition of fiber to a high-fat, high-calorie (HFHC) meal prevents proinflammatory changes induced by the HFHC meal. Design: Ten normal fasting subjects consumed an HFHC meal with or without an additional 30 g of insoluble dietary fiber on 2 separate visits. Blood samples were collected over 5 hours, and mononuclear cells (MNCs) were isolated. Results: Fiber addition to the HFHC meal significantly lowered glucose excursion in the first 90 minutes and increased insulin and C-peptide secretion throughout the 5-hour follow-up period compared with the meal alone. The HFHC meal induced increases in lipopolysaccharide (LPS) concentrations, MNC reactive oxygen species generation, and the expression of interleukin (IL)-1ß, tumor necrosis factor α (TNF-α), Toll-like receptor (TLR)-4, and CD14. The addition of fiber prevented an increase in LPS and significantly reduced the increases in ROS generation and the expression of IL-1ß, TNF-α, TLR-4, and CD14. In addition, the meal increased Suppressor of cytokine signaling (SOCS)-3 and protein tyrosine phosphatase 1B (PTP-1B) messenger RNA and protein levels, which were inhibited when fiber was added. Conclusions: The addition of fiber to a proinflammatory HFHC meal had beneficial anti-inflammatory and metabolic effects. Thus, the fiber content of the American Heart Association meal may contribute to its noninflammatory nature. If these actions of dietary fiber are sustained following long-term intake, they may contribute to fiber's known benefits in the prevention of insulin resistance, type 2 diabetes, and atherosclerosis.

Oxytocin Improves ß-Cell Responsivity and Glucose Tolerance in Healthy Men.

In addition to its pivotal role in psychosocial behavior, the hypothalamic neuropeptide oxytocin contributes to metabolic control by suppressing eating behavior. Its involvement in glucose homeostasis is less clear, although pilot experiments suggest that oxytocin improves glucose homeostasis. We assessed the effect of intranasal oxytocin (24 IU) administered to 29 healthy, fasted male subjects on glucose homeostasis measured by means of an oral glucose tolerance test. Parameters of glucose metabolism were analyzed according to the oral minimal model. Oxytocin attenuated the peak excursion of plasma glucose and augmented the early increases in insulin and C-peptide concentrations in response to the glucose challenge, while slightly blunting insulin and C-peptide peaks. Oral minimal model analyses revealed that oxytocin compared with placebo induced a pronounced increase in ß-cell responsivity (PHItotal) that was largely due to an enhanced dynamic response (PHId), and a more than twofold improvement in glucose tolerance (disposition index). Adrenocorticotropic hormone (ACTH), cortisol, glucagon, and nonesterified fatty acid (NEFA) concentrations were not or were only marginally affected. These results indicate that oxytocin plays a significant role in the acute regulation of glucose metabolism in healthy humans and render the oxytocin system a potential target of antidiabetic treatment.

The effect of oral and intravenous dextrose on C-peptide secretion in ponies.

Managing equine hyperinsulinemia is crucial for preventing laminitis, but our understanding of the mechanisms involved in insulin dysregulation in this species is incomplete. C-peptide is co-secreted with insulin but is resistant to hepatic metabolism and can be used to study insulin dysregulation. This study examined C-peptide secretion in serial blood samples collected after oral and i.v. dextrose (0.75 g/kg) administration to 9 ponies (BCS, 7.1 ± 0.5). The ponies were designated as hyperinsulinemic (HI) or normoinsulinemic (NI) responders before the study, using oral glucose tests and fasted glucose-to-insulin ratios, and responses were compared between the 2 groups. C-peptide concentrations increased ( < 0.01) rapidly from fasted levels after both oral and i.v. dextrose, with similar area under the concentration-time curve (AUC) for both tests and a significant correlation with AUC. The AUC was similar in HI and NI ponies after i.v. dextrose, indicating similar pancreatic capacity for both groups. However, for oral dextrose, the AUC and the AUC were markedly higher ( < 0.05) in the HI ponies, indicating a greater secretion rate of these peptides. Slower insulin clearance might have also contributed to the larger AUC in HI ponies, but this hypothesis requires further investigation with specific measures of hepatic insulin clearance.

Markers of ß-Cell Failure Predict Poor Glycemic Response to GLP-1 Receptor Agonist Therapy in Type 2 Diabetes.

OBJECTIVE: To assess whether clinical characteristics and simple biomarkers of ß-cell failure are associated with individual variation in glycemic response to GLP-1 receptor agonist (GLP-1RA) therapy in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: We prospectively studied 620 participants with type 2 diabetes and HbA1c ≥58 mmol/mol (7.5%) commencing GLP-1RA therapy as part of their usual diabetes care and assessed response to therapy over 6 months. We assessed the association between baseline clinical measurements associated with ß-cell failure and glycemic response (primary outcome HbA1c change 0-6 months) with change in weight (0-6 months) as a secondary outcome using linear regression and ANOVA with adjustment for baseline HbA1c and cotreatment change. RESULTS: Reduced glycemic response to GLP-1RAs was associated with longer duration of diabetes, insulin cotreatment, lower fasting C-peptide, lower postmeal urine C-peptide-to-creatinine ratio, and positive GAD or IA2 islet autoantibodies (P ≤ 0.01 for all). Participants with positive autoantibodies or severe insulin deficiency (fasting C-peptide ≤0.25 nmol/L) had markedly reduced glycemic response to GLP-1RA therapy (autoantibodies, mean HbA1c change -5.2 vs. -15.2 mmol/mol [-0.5 vs. -1.4%], P = 0.005; C-peptide <0.25 nmol/L, mean change -2.1 vs. -15.3 mmol/mol [-0.2 vs. -1.4%], P = 0.002). These markers were predominantly present in insulin-treated participants and were not associated with weight change. CONCLUSIONS: Clinical markers of low ß-cell function are associated with reduced glycemic response to GLP-1RA therapy. C-peptide and islet autoantibodies represent potential biomarkers for the stratification of GLP-1RA therapy in insulin-treated diabetes.

Safety, efficacy and weight effect of two 11ß-HSD1 inhibitors in metformin-treated patients with type 2 diabetes.

AIMS: We assessed safety and efficacy of two selective 11ß-HSD1 inhibitors (RO5093151/RO-151 and RO5027383/RO-838) in this randomized, controlled study in metformin-treated patients with type 2 diabetes. METHODS: Patients either received placebo (N = 21), RO-151 BID 5 mg (N = 24) or 200 mg (N = 20) or RO-838 QD 50 mg (N = 21) or 200 mg (N = 24) for 28 days. Metabolic assessments comprising of nine-point plasma glucose profiles, oral glucose tolerance tests and determination of metabolic biomarkers including insulin, C-peptide, glucagon, HbA1c and lipids were done at baseline and end of treatment. RESULTS: Despite the short treatment duration, both RO-151 and RO-838 showed trends for improved HbA1c and consistent reductions in body weight (-0.86 to -1.67 kg) exceeding those observed with placebo (-0.28 kg, p = 0.019 for 200 mg RO-151 vs. placebo). Insulin sensitivity parameters (e.g. HOMA-IR and Matsuda-Index) improved non-significantly with 200 mg RO-151. Lipid parameters did not consistently improve with either compound, but RO-838 led to non-significant increases in triglycerides and VLDL-cholesterol versus placebo. Both compounds were well tolerated and showed inhibitory effects on 11ß-HSD1 activity based on urinary corticosteroid excretion. As reported for other 11ß-HSD1-inhibitors increased concentrations of ACTH and adrenal androgen precursors were found with RO-151, but not with RO-838. CONCLUSIONS: Slight metabolic improvements were seen, in particular with RO-151 high dose, however, the observed changes often did not reach statistical significance and were not clearly dose dependent. Studies of longer duration are needed to further investigate potential benefits and risks of these compounds.

Steady-state pharmacokinetics and glucodynamics of the novel, long-acting basal insulin LY2605541 dosed once-daily in patients with type 2 diabetes mellitus.

AIMS: To assess the pharmacokinetics (PK) and glucodynamics (GD) of LY2605541 in patients with type 2 diabetes mellitus. METHODS: This parallel-group, open-label, dose-escalation study examined the PK and GD of basal insulin LY2605541 after single and multiple-dose administration. Fixed doses of LY2605541 (0.33-1.00 U/kg) were given once-daily (QD) for 14 days to insulin-treated patients with type 2 diabetes. A 24-h euglycaemic glucose clamp was conducted on days 1 and 14. RESULTS: PK steady state was achieved within 7-10 days and the peak-to-trough fluctuation was <2, translating to a nearly 'peakless' glucose infusion rate at steady state and with a duration of action of at least 24 h. Across dose levels t1/2 ranged from 44.7 to 75.5 h (~2-3 days). As steady state was achieved, there were dose-dependent reductions in the prandial insulin dose and in fasting blood glucose, which decreased to 60-100 mg/dl across dose levels. Within-patient variability was <14 and <26% for the area under the concentration versus time curve (AUC) of the 8-point blood glucose profile and fasting blood glucose, respectively. The nocturnal glucose control between 03:00 and 09:00 hours was relatively unchanged. Mild hypoglycaemia was the most common adverse event. CONCLUSIONS: In this Phase I study of fixed LY2605541 doses without titration, LY2605541 was well-tolerated and demonstrated a flat PK and GD profile accompanied by glucose normalization, prandial insulin dose reduction and no severe hypoglycaemia.

Pharmacokinetic properties and effects of PT302 after repeated oral glucose loading tests in a dose-escalating study.

BACKGROUND: PT302 is a sustained-release exenatide under clinical development for the treatment of type 2 diabetes mellitus. OBJECTIVE: The aim of this study was to evaluate the pharmacokinetic properties, pharmacodynamic properties, and tolerability of PT302 after a single subcutaneous injection in healthy individuals. METHODS: A dose-block randomized, double-blind, placebo-controlled, dose-escalating study (0.5, 1, 2, and 4 mg) was performed in 34 healthy individuals. The plasma concentrations of exenatide in serial blood samples were quantified for 56 days after dosing with an exendin-4 fluorescent immunoassay kit. Noncompartmental analysis was performed to assess the pharmacokinetic characteristics of PT302. Oral glucose tolerance tests were repeated weekly until day 42; the concentrations of serum glucose, serum C-peptide, plasma insulin, and plasma glucagon were measured for 2 hours to evaluate the pharmacodynamic characteristics of PT302. Clinical laboratory tests, vital signs, physical examinations, 12-lead ECGs, and adverse events were monitored to evaluate the safety profile and tolerability. RESULTS: PT302 exhibits a biphasic pharmacokinetic profile, with the initial peak occurring 2 hours after administration. PT302 was quantifiable in the plasma until days 23, 30, 32, and 55 (median) in the 0.5-mg, 1-mg, 2-mg, and 4-mg dosage groups of PT302, respectively. Systemic exposure increased proportionally to the dose during the entire dose range investigated. The pharmacodynamic effect of PT302 on the postprandial response of insulin and C-peptide was significant on days 21 to 28 at the 4-mg dose and was positively correlated with plasma exenatide concentrations, whereas the correlations with glucose and glucagon were not significant. The fasting levels of these pharmacodynamic biomarkers were not altered by PT302. The most common adverse events were injection site induration and pruritus related to inflammatory foreign body reaction, which were mild and spontaneously resolved within several weeks. CONCLUSION: The pharmacokinetic characteristics of PT302 were biphasic and dose proportional. A single 4-mg dose of PT302 significantly increased the insulin and C-peptide response to oral glucose loading and was well tolerated in healthy individuals.

Interleukin-1 antagonism in type 1 diabetes of recent onset: two multicentre, randomised, double-blind, placebo-controlled trials.

BACKGROUND: Innate immunity contributes to the pathogenesis of autoimmune diseases, such as type 1 diabetes, but until now no randomised, controlled trials of blockade of the key innate immune mediator interleukin-1 have been done. We aimed to assess whether canakinumab, a human monoclonal anti-interleukin-1 antibody, or anakinra, a human interleukin-1 receptor antagonist, improved ß-cell function in recent-onset type 1 diabetes. METHODS: We did two randomised, placebo-controlled trials in two groups of patients with recent-onset type 1 diabetes and mixed-meal-tolerance-test-stimulated C peptide of at least 0·2 nM. Patients in the canakinumab trial were aged 6-45 years and those in the anakinra trial were aged 18-35 years. Patients in the canakinumab trial were enrolled at 12 sites in the USA and Canada and those in the anakinra trial were enrolled at 14 sites across Europe. Participants were randomly assigned by computer-generated blocked randomisation to subcutaneous injection of either 2 mg/kg (maximum 300 mg) canakinumab or placebo monthly for 12 months or 100 mg anakinra or placebo daily for 9 months. Participants and carers were masked to treatment assignment. The primary endpoint was baseline-adjusted 2-h area under curve C-peptide response to the mixed meal tolerance test at 12 months (canakinumab trial) and 9 months (anakinra trial). Analyses were by intention to treat. These studies are registered with ClinicalTrials.gov, numbers NCT00947427 and NCT00711503, and EudraCT number 2007-007146-34. FINDINGS: Patients were enrolled in the canakinumab trial between Nov 12, 2010, and April 11, 2011, and in the anakinra trial between Jan 26, 2009, and May 25, 2011. 69 patients were randomly assigned to canakinumab (n=47) or placebo (n=22) monthly for 12 months and 69 were randomly assigned to anakinra (n=35) or placebo (n=34) daily for 9 months. No interim analyses were done. 45 canakinumab-treated and 21 placebo-treated patients in the canakinumab trial and 25 anakinra-treated and 26 placebo-treated patients in the anakinra trial were included in the primary analyses. The difference in C peptide area under curve between the canakinumab and placebo groups at 12 months was 0·01 nmol/L (95% CI -0·11 to 0·14; p=0·86), and between the anakinra and the placebo groups at 9 months was 0·02 nmol/L (-0·09 to 0·15; p=0·71). The number and severity of adverse events did not differ between groups in the canakinumab trial. In the anakinra trial, patients in the anakinra group had significantly higher grades of adverse events than the placebo group (p=0·018), which was mainly because of a higher number of injection site reactions in the anakinra group. INTERPRETATION: Canakinumab and anakinra were safe but were not effective as single immunomodulatory drugs in recent-onset type 1 diabetes. Interleukin-1 blockade might be more effective in combination with treatments that target adaptive immunity in organ-specific autoimmune disorders. FUNDING: National Institutes of Health and Juvenile Diabetes Research Foundation.

The duration of sulfonylurea treatment is associated with ß-cell dysfunction in patients with type 2 diabetes mellitus.

BACKGROUND: This study investigated the incidence of ß-cell dysfunction and the clinical and biochemical factors affecting that in patients with type 2 diabetes having more than 3 years of follow-up. SUBJECTS AND METHODS: ß-Cell dysfunction was assessed by measuring changes in the fasting serum C-peptide concentrations. Patients were classified into two groups: cases showing a decreased (Group D) or an unchanged or increased (Group I) C-peptide concentration from the baseline. RESULTS: Of the 504 patients included in this study, 259 (51%) showed decreased C-peptide concentrations, of whom 20% showed a decrease of ≥50%. Most patients, however, had a final C-peptide concentration of ≥1 ng/mL, with only 18 (4%) individuals having a level <0.6 ng/mL. Patients in Group D had a longer duration of diabetes, higher initial hemoglobin A1c concentration, and longer treatment durations with sulfonylurea and insulin compared with Group I. After adjusting for diabetes duration and C-peptide follow-up period, the duration of sulfonylurea treatment was found to be the only factor independently associated with decreases in the C-peptide concentration. CONCLUSIONS: Although ß-cell function deteriorates over time in patients with type 2 diabetes, these cases mainly have fasting serum C-peptide concentrations of ≥1 ng/mL. A longer treatment duration with sulfonylurea is associated with a more rapid decline in the C-peptide concentration.

Insulin secretion and sensitivity after single-dose amisulpride, olanzapine or placebo in young male subjects: double blind, cross-over glucose clamp study.

INTRODUCTION: Increased risks of weight gain and diabetes mellitus have been reported for schizophrenic patients under long-term treatment with several atypical antipsychotic drugs including olanzapine. Among other antipsychotic drugs, treatment with the selective dopamine D2 and D3 receptor antagonist amisulpride has been implicated with a lower risk for metabolic complications. PATIENTS AND METHODS: In this study we compared the acute, non-adiposity related effects of a single dose of olanzapine, amisulpride and placebo on insulin sensitivity and secretion in 10 healthy subjects in a randomised, double blind cross-over design. Subjects underwent euglycemic-hyperinsulinemic and hyperglycemic clamp tests using an automated clamp device. C-peptide and pro-insulin levels were determined using highly specific immuno-assays. RESULTS: Insulin sensitivity was not significantly different between both verum medications and placebo. However, C-peptide secretion during hyperglycemic clamp was significantly higher after administration of amisulpride than after olanzapine or placebo. This was true both for the early phase and for the second phase of insulin secretion (C-peptide at 0, 5,10 and 30 min: amisulpride 1.49±0.49; 4.22±1.45; 3.19±1.22; 5.33±1.85; olanzapine 1.35±0.47; 3.84±1.37; 2.72±0.91; 4.28±1.96; placebo 1.72±0.82; 3.59±1.19; 2.71±1.02; 4.54±1.42 ng/mL, mean±SD; ANOVA p=0.043). Pro-insulin levels did not differ significantly between groups. DISCUSSION: A low dose of the D2/D3 antagonist amisulpride, but not olanzapine appears to acutely increase pancreatic insulin secretion in healthy controls. Stimulation of ß-cells could be a protective factor against the development of diabetes mellitus.