Comparison of incretin immunoassays with or without plasma extraction: Incretin secretion in Japanese patients with type 2 diabetes

Glucagon-like peptide-1 and interleukin-6 interaction in response to physical exercise: An in-silico model in the framework of immunometabolism

BACKGROUND AND OBJECTIVE

Glucagon-like peptide 1 (GLP-1) is classically identified as an incretin hormone, secreted in response to nutrient ingestion and able to enhance glucose-stimulated insulin secretion. However, other stimuli, such as physical exercise, may enhance GLP-1 plasma levels, and this exercise-induced GLP-1 secretion is mediated by interleukin-6 (IL-6), a cytokine secreted by contracting skeletal muscle. The aim of the study is to propose a mathematical model of IL-6-induced GLP-1 secretion and kinetics in response to physical exercise of moderate intensity.

METHODS

The model includes the GLP-1 subsystem (with two pools: gut and plasma) and the IL-6 subsystem (again with two pools: skeletal muscle and plasma); it provides a parameter of possible clinical relevance representing the sensitivity of GLP-1 to IL-6 (k0). The model was validated on mean IL-6 and GLP-1 data derived from the scientific literature and on a total of 100 virtual subjects.

RESULTS

Model validation provided mean residuals between 0.0051 and 0.5493 pg⋅mL-1 for IL-6 (in view of concentration values ranging from 0.8405 to 3.9718 pg⋅mL-1) and between 0.0133 and 4.1540 pmol⋅L-1 for GLP-1 (in view of concentration values ranging from 0.9387 to 17.9714 pmol⋅L-1); a positive significant linear correlation (r = 0.85, p<0.001) was found between k0 and the ratio between areas under GLP-1 and IL-6 curve, over the virtual subjects.

CONCLUSIONS

The model accurately captures IL-6-induced GLP-1 kinetics in response to physical exercise.

Administration of Jerusalem artichoke reduces the postprandial plasma glucose and glucose-dependent insulinotropic polypeptide (GIP) concentrations in humans

Background

The consumption of Jerusalem artichoke has multiple beneficial effects against diabetes and obesity.

Objective

The aim of this study was to determine the effect of a single administration of Jerusalem artichoke tubers on postprandial glycemia and the concentrations of incretin hormones in humans.

Method

Grated Jerusalem artichoke was administered prior to a meal (Trial 1; white rice for prediabetic participants, n = 10). Dose-dependent effect of Jerusalem artichoke (Trial 2; white rice for prediabetic participants, n = 4) and effect prior to the fat-rich meal were also investigated (Trial 3; healthy participants, n = 5) in this pilot study. Circulating glucose, insulin, triglyceride, glucagon, active glucagon-like peptide-1 (GLP-1), and active glucose-dependent insulinotropic polypeptide (GIP) concentrations were subsequently measured in all the trials.

Results

Jerusalem artichoke significantly reduced the glucose and GIP concentrations after the consumption of either meal in Trial 1 and Trial 3, whereas there were no differences in the insulin, glucagon, and active GLP-1 concentrations. Also, there was no significant difference in the triglyceride concentration after the ingestion of the fat-rich meal in Trial 3. The glucose and GIP-lowering effects were dose-dependent, and the consumption of at least 100 g of Jerusalem artichoke was required to have these effects in Trial 2.

Conclusion

This study demonstrates that a single administration of Jerusalem artichoke tubers reduces postprandial glucose and active GIP concentrations in prediabetic and healthy individuals.

Effects of glucagon-like peptide-1 receptor agonists on secretions of insulin and glucagon and gastric emptying in Japanese individuals with type 2 diabetes: A prospective, observational study

AIMS/INTRODUCTION

Differences in the glucose-lowering mechanisms of glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been noted. Clarifying these differences could facilitate the choice of optimal drugs for individuals with type 2 diabetes and requires investigation in a clinical setting.

MATERIALS AND METHODS

A single-arm, prospective, observational study was conducted to evaluate the effects of various GLP-1RAs on postprandial glucose excursion, secretions of insulin and glucagon as well as on the gastric emptying rate. Participants were subjected to meal tolerance tests before and 2 weeks and 12 weeks after GLP-1RA initiation. Effects on postprandial secretions of glucose-dependent insulinotropic polypeptide (GIP) and apolipoprotein B48 were also investigated.

RESULTS

Eighteen subjects with type 2 diabetes received one of three GLP-1RAs, i.e., lixisenatide, n = 7; liraglutide, n = 6; or dulaglutide, n = 5. While 12-week administration of all of the GLP-1RAs significantly reduced HbA1c, only lixisenatide and liraglutide, but not dulaglutide, significantly reduced body weight. Postprandial glucose elevation was improved by all of the GLP-1RAs. Postprandial insulin levels were suppressed by lixisenatide, while insulin levels were enhanced by liraglutide. Postprandial glucagon levels were suppressed by lixisenatide. The gastric emptying rate was significantly delayed by lixisenatide, while liraglutide and dulaglutide had limited effects on gastric emptying. GIP secretion was suppressed by lixisenatide and liraglutide. Apolipoprotein B48 secretion was suppressed by all of the GLP-1RAs.

CONCLUSIONS

All of the GLP-1RAs were found to improve HbA1c in a 12-week prospective observational study in Japanese individuals with type 2 diabetes. However, differences in the mechanisms of the glucose-lowering effects and body weight reduction were observed.

Efficacy and Safety of Miglitol- or Repaglinide-Based Combination Therapy with Alogliptin for Drug-Naïve Patients with Type 2 Diabetes: An Open-Label, Single-Center, Parallel, Randomized Controlled Pilot Study

BACKGROUND

Combination therapy with an alpha-glucosidase inhibitor or glinide plus a dipeptidyl peptidase-4 inhibitor is thought to be effective for glycemic control because of its effects on postprandial hyperglycemia. However, no studies have directly compared these two combination therapies in relation to efficacy and safety.

METHODS

Eighteen patients with type 2 diabetes were studied. All had diabetes not adequately controlled with diet and exercise therapy, an HbA1c level of ≥7.5%, and were not receiving any medication for diabetes. The patients were randomized to either miglitol- or repaglinide-based combination therapy with alogliptin. Patients received miglitol or repaglinide monotherapy for 3 months (the miglitol and repaglinide groups, respectively), after which alogliptin was added to each group as combination therapy for 3 months. A meal tolerance test (MTT) was performed before the start of treatment and at the end of monotherapy and combination therapy.

RESULTS

During the study period, decreases in HbA1c and glycated albumin were significantly greater in the repaglinide group than in the miglitol group; however, there was no significant difference between treatment groups at the end of the study. At the end of monotherapy, insulin secretion relative to glucose elevation (ISG_0-30: area under the curve of insulin from 0 to 30 min during MTT [AUC_0-30 of IRI]/AUC_0-30 of plasma glucose) was significantly higher only in the repaglinide group; ISG_0-30 did not significantly increase in either group after the addition of alogliptin.

CONCLUSIONS

The addition of alogliptin to repaglinide monotherapy did not cause glucose-independent inappropriate insulin secretion and did not appear to increase the incidence of hypoglycemia.

Effect of tasteless calorie-free gum chewing before meal on postprandial plasma glucose, insulin, glucagon, and gastrointestinal hormones in Japanese men without diagnosed glucose metabolism disorder: a pilot randomized crossover trial

This pilot study aimed to examine the effect of pre-meal tasteless calorie-free gum chewing on post-meal blood levels of glucose, insulin, glucagon, and gastrointestinal hormones. This was an open-label, randomized, 2-sequence, 3-period, 2-treatment crossover trial with a 1:1 allocation. Sixteen Japanese adult male volunteers aged between 30 and 49 years without diagnosed glucose metabolism disorder were enrolled. Ingestion of 200-g cooked rice after 15-min tasteless calorie-free gum chewing (GUM+ treatment) was compared to that without preceding gum chewing (GUM- treatment). Cooked rice was divided into twelve equally sized portions and consumed by chewing each portion 30 times before swallowing. Treatment sessions were separated by an at least 1-week interval and attended after an overnight fast. Circulating levels of glucose, insulin, glucagon, active glucagon-like peptide (GLP)-1 and ghrelin were measured at baseline (before treatment) and 0, 15, 30, 60, and 120 min after completion of the meal ingestion, and the postprandial change from baseline was assessed. As a result, the change in glucose levels at 0 min was significantly lower in the GUM+ treatment than in the GUM- treatment (P = 0.004). Furthermore, the GUM+ treatment demonstrated higher incremental insulin levels at 15 min (P = 0.041) and higher incremental active GLP-1 levels at 30 and 60 min (P = 0.018 and 0.021, respectively); whereas, postprandial glucagon and ghrelin levels were not significantly different. In conclusion, the current pilot study demonstrated that tasteless calorie-free gum chewing before rice eating had a significant but limited impact on the increase of postprandial active GLP-1 levels in male individuals without diagnosed glucose metabolism disorder.

Canagliflozin Increases Postprandial Total Glucagon-Like Peptide 1 Levels in the Absence of α-Glucosidase Inhibitor Therapy in Patients with Type 2 Diabetes: A Single-Arm, Non-randomized, Open-Label Study

INTRODUCTION

To investigate canagliflozin-induced changes in postprandial total glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) levels in patients with type 2 diabetes mellitus (T2DM).

METHODS

Forty-five patients with T2DM who had inadequate glycemic control (glycated hemoglobin ≥ 6.5%) with diet and exercise alone (n = 15, drug naïve) and in combination with either a stable dose of the α-glucosidase inhibitor acarbose (n = 15) or metformin (n = 15) received canagliflozin, a sodium-glucose cotransporter 2 inhibitor, at 100 mg once daily for 12 weeks. The primary endpoint was the change from baseline to week 12 in postprandial glucose and plasma levels of total GLP-1 and GIP during a meal tolerance test (MTT).

RESULTS

Canagliflozin significantly reduced postprandial blood glucose (mean difference - 40.2 mg/mL at 60 min) and increased postprandial total GLP-1 (mean difference 1.8 pg/mL at 60 min) during an MTT. A transient reduction in the postprandial GIP level at only 30 min (mean difference - 80.3 pg/mL) during an MTT was observed. No changes in postprandial GLP-1 or GIP levels were seen after canagliflozin treatment as an add-on to acarbose in patients with T2DM. Acarbose treatment significantly decreased postprandial total GIP levels (P < 0.05) and tended to increase postprandial total GLP-1 levels (P = 0.07) compared to the other two treatments prior to canagliflozin.

CONCLUSION

Canagliflozin 100 mg increased postprandial total GLP-1 levels in the absence of acarbose, suggesting that it may upregulate GLP-1 secretion through delayed glucose absorption in the upper intestine, as with the α-glucosidase inhibitor.

TRIAL REGISTRATION

University Hospital Medical Information Network, UMIN000018345.

FUNDING

Mitsubishi Tanabe Pharma Corporation.

Effects of anagliptin on plasma glucagon levels and gastric emptying in patients with type 2 diabetes: An exploratory randomized controlled trial versus metformin

AIMS

Glucagon has an important role in glucose homeostasis. Recently, a new plasma glucagon assay based on liquid chromatography-high resolution mass spectrometry was developed. We evaluated the influence of a dipeptidyl peptidase-4 inhibitor (anagliptin) on plasma glucagon levels in Japanese patients with type 2 diabetes by using this new assay.

METHODS

Twenty-four patients with type 2 diabetes were enrolled in a prospective, single-center, randomized, open-label study and were randomly allocated to 4 weeks of treatment with metformin (1000 mg/day) or anagliptin (200 mg/day). A liquid test meal labeled with sodium [¹³C] acetate was ingested before and after the treatment period. Samples of blood and expired air were collected over 3 h. Plasma levels of glucose, glucagon, C-peptide, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) were measured, and gastric emptying was also evaluated.

RESULTS

Twenty-two patients completed the study (metformin group: n = 10; anagliptin group: n = 12). Glycemic control showed similar improvement in both groups. In the anagliptin group, there was a slight decrease of the incremental area under the plasma concentration versus time curve for glucagon after the test meal (P = 0.048). In addition, the plasma level of active GLP-1 and GIP was increased, and plasma C-peptide was also increased versus baseline. Neither anagliptin nor metformin delayed gastric emptying.

CONCLUSIONS

In patients with type 2 diabetes maintained endogenous insulin secretion, anagliptin increased the plasma level of active GLP-1 and GIP in association with a slight stimulation of insulin secretion and slight inhibition of glucagon secretion, but did not delay gastric emptying. Clinical Trial Registry: University hospital Medical Information Network UMIN000028293.

Low-carbohydrate diet by staple change attenuates postprandial GIP and CPR levels in type 2 diabetes patients

AIMS

The aim of this study is to investigate the effects of a low-carbohydrate staple food (i.e., low-carbohydrate bread) on glucose and lipid metabolism and pancreatic and enteroendocrine hormone secretion in comparison with meals containing normal-carbohydrate bread, without consideration of the carbohydrate content of the side dishes.

METHODS

T2DM patients (n = 41) were provided meals containing low-carbohydrate bread (LB) together with side dishes or normal-carbohydrate bread (NB) together with side dishes every other day as a breakfast. Blood glucose levels were evaluated by using a continuous glucose monitoring system; blood samples were collected before and 1 and 2 h after the breakfast.

RESULTS

Postprandial blood glucose levels, plasma insulin, plasma glucose-dependent insulinotropic polypeptide (GIP) and plasma triglyceride were significantly lower and plasma glucagon levels were significantly higher in LB compared with those in NB. Plasma glucagon-like peptide-1 (GLP-1) levels did not differ in the LB and NB groups.

CONCLUSIONS

These results indicate that changing only the carbohydrate content of the staple food has benefits on glucose and lipid metabolism in T2DM patients concomitant with the decrease of insulin and GIP secretion, which ameliorate body weight gain and insulin resistance.

Solid-phase extraction treatment is required for measurement of active glucagon-like peptide-1 by enzyme-linked immunosorbent assay kit affected by heterophilic antibodies

AIMS/INTRODUCTION

It is reported that interfering substances in the blood might influence the value for measurement of active glucagon-like peptide-1 (GLP-1) in human plasma. Solid phase extraction (SPE) pretreatment is recommended to reduce their influence, but it requires a lot of cost and time. However, there is little investigation about causative inhibitory substances and about methods that can replace solid phase extraction. In the present study, we aimed to seek the candidate of the substances that might interfere with an active GLP-1 enzyme-linked immunosorbent assay (ELISA).

MATERIALS AND METHODS

Two kinds of active GLP-1 ELISA kits using different antibodies, plural extraction carriers and elution solutions were used to evaluate the SPE method. Active GLP-1 concentration was compared with or without SPE, and with or without a heterophilic blocking tube.

RESULTS

Active GLP-1 values were often higher without SPE compared with those with SPE pretreatment. This difference was eliminated by pretreatment with a heterophilic blocking tube or ELISA kits that did not use a mouse monoclonal antibody, and was independent of SPE.

CONCLUSIONS

Substances absorbed to a heterophilic blocking tube carrier might interfere with an active GLP-1 immunoassay. Solid-phase extraction treatment is required for measurement of active GLP-1 by an ELISA kit affected by heterophilic antibodies.

Ursodeoxycholic acid potentiates dipeptidyl peptidase-4 inhibitor sitagliptin by enhancing glucagon-like peptide-1 secretion in patients with type 2 diabetes and chronic liver disease: a pilot randomized controlled and add-on study

OBJECTIVE

We evaluated the effects of ursodeoxycholic acid (UDCA) on glucagon-like peptide-1 (GLP-1) secretion and glucose tolerance in patients with type 2 diabetes with chronic liver disease.

RESEARCH DESIGN AND METHODS

Japanese patients with type 2 diabetes (glycated hemoglobin (HbA1c) levels ≥7.0%) and chronic liver disease were included in this study. Sixteen patients (HbA1c level, 7.2%±0.6%(55.2 mmol/mol)) were randomized to receive 900 mg UDCA for 12 weeks followed by 50 mg sitagliptin add-on therapy for 12 weeks (UDCA-first group; n=8) or 50 mg sitagliptin for 12 weeks followed by 900 mg UDCA add-on therapy for 12 weeks (sitagliptin-first group; n=8). All patients underwent a liquid high-fat meal test before and after 12 or 24 weeks of treatment.

RESULTS

The baseline characteristics were similar between the UDCA-first and sitagliptin-first groups. There was a decrease in body weight (72.5±8.4 to 70.6±8.6 kg; P=0.04) and the HbA1c level (7.0%±0.3% to 6.4%±0.5%(53.0 to 46.4 mmol/mol); P=0.01) in the UDCA-first group. The HbA1c level decreased further after sitagliptin administration (6.4%±0.5% to 6.0%±0.4%(46.4 to 42.1 mmol/mol); P<0.01). Although there were no initial changes in the weight and HbA1c level in the sitagliptin-first group, the HbA1c level decreased after UDCA addition (7.1%±1.1% to 6.6%±0.9%(54.1 to 48.6 mmol/mol); P=0.04). UDCA alone increased the area under the curve_0-30 for GLP-1 response (115.4±47.2 to 221.9±48.9 pmol·min/L; P<0.01), but not the glucose-dependent insulinotropic polypeptide response, in the UDCA-first group.

CONCLUSIONS

UDCA treatment resulted in a greater reduction in HbA1c levels, and an increased early phase GLP-1 secretion.

TRIAL REGISTRATION NUMBER

NCT01337440.

Sitagliptin 100 mg vs glimepiride 1-3 mg as an add-on to insulin and metformin in type 2 diabetes (SWIM)

OBJECTIVE

To compare the effect of sitagliptin (100 mg) vs glimepiride (1-3 mg) as add-on therapy in Indian type 2 diabetes (T2DM) patients on treatment with insulin and metformin (SWIM study).

RESEARCH DESIGN AND METHODS

This 24-week, controlled, open-label study randomized T2DM patients (n = 440) receiving a stable dose of metformin and insulin combination therapy to sitagliptin (100 mg) or glimepiride (1-3 mg) as add-on therapy. Baseline HbA1c was ≥7.3% and ≤8.5%. After a 6-week titration period for glimepiride (dose titrated every 2 weeks by 1 mg up to a maximum of 3 mg daily), patients were continued for 18 weeks on their respective tolerable doses of glimepiride (ranging from 1 mg to 3 mg) or sitagliptin (100 mg) along with metformin and insulin.

RESULTS

Greater reductions in HbA1c and TDD of insulin were achieved with sitagliptin compared to glimepiride. HbA1c targets and reductions in TDD were achieved by more patients on sitagliptin than on glimepiride. Reductions in both body weight and BMI were also noted among patients on sitagliptin when compared to those on glimepiride, and more hypoglycemic events occurred with glimepiride treatment than with sitagliptin.

CONCLUSIONS

Sitagliptin (100 mg), when compared to glimepiride (1-3 mg), bestowed beneficial effects to T2DM patients in terms of achieving greater glycemic control and also brought significant reductions in total daily dose of insulin required, bodyweight, BMI and hypoglycemic events. Overall, the results suggest that sitagliptin (100 mg) is a superior agent over glimepiride (1-3 mg) as an add-on to insulin-metformin therapy among Asian Indians with T2DM.

The Role of Glucagon-like Peptide-1 Receptor Agonists in the Treatment of Type 2 Diabetes

The role of GLP-1 agonists in the treatment of type 2 diabetes have been shown to be viable options for add-on therapy in diabetic patients, as well as potential monotherapy options. With six available GLP-1 agents, and new combination products in the pipeline, they are a promising drug class for type 2 diabetic patients, especially due to their extended dosing interval and potential weight loss benefits.

What next after basal insulin? Treatment intensification with lixisenatide in Asian patients with type 2 diabetes mellitus

There is increasing evidence that the pathophysiology of type 2 diabetes mellitus (T2DM) in Asian patients differs from that in Western patients, with early phase insulin deficiencies, increased postprandial glucose excursions, and increased sensitivity to insulin. Asian patients may also experience higher rates of gastrointestinal adverse events associated with glucagon-like peptide-1 receptor agonists (GLP-1RAs), such as nausea and vomiting, compared with their Western counterparts. These factors should be taken into consideration when selecting therapy for basal insulin treatment intensification in Asian patients. However, the majority of studies to establish various agents for treatment intensification in T2DM have been conducted in predominantly Western populations, and the levels of evidence available in Chinese or Asian patients are limited. This review discusses the different mechanisms of action of short-acting, prandial, and long-acting GLP-1RAs in addressing hyperglycemia, and describes the rationale and available clinical data for basal insulin in combination with the short-acting prandial GLP-1RA lixisenatide, with a focus on treatment of Asian patients with T2DM.

Glucose-lowering effects and safety of DS-8500a, a G protein-coupled receptor 119 agonist, in Japanese patients with type 2 diabetes: results of a randomized, double-blind, placebo-controlled, parallel-group, multicenter, phase II study

OBJECTIVE

DS-8500a is a novel G protein-coupled receptor 119 agonist being developed for the treatment of type 2 diabetes. The study objective was to assess the efficacy and safety of DS-8500a in Japanese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this double-blind, parallel-group, phase II study, 99 Japanese patients with type 2 diabetes were randomized to receive placebo, or DS-8500a 10 mg or 75 mg once daily for 28 days. The primary efficacy endpoint was change in the 24-hour weighted mean glucose (WMG) from baseline (day -1) to day 28. Other endpoints included changes in fasting plasma glucose, postprandial glucose, lipids, and safety.

RESULTS

The 24-hour WMG decreased significantly after 28 days of treatment in the 10 mg and 75 mg groups with placebo-subtracted least squares mean differences (95% CI) of -0.74 (-1.29 to -0.19) mmol/L and -1.05 (-1.59 to -0.50) mmol/L, respectively. Reductions in 24-hour WMG in both DS-8500a groups were observed on day 14 and were greater on day 28 than on day 14. The reductions in fasting plasma glucose and 2-hour postprandial glucose were significantly greater in the 75 mg DS-8500a group versus placebo. Total cholesterol, low-density lipoprotein cholesterol, and triglycerides decreased significantly; high-density lipoprotein cholesterol increased significantly in the 75 mg group versus placebo. Both doses of DS-8500a were well tolerated without significant treatment-related adverse events, hypoglycemia, or discontinuations due to adverse events.

CONCLUSIONS

DS-8500a significantly improved glycemic control and lipids and was well tolerated over 28 days of administration in Japanese patients with type 2 diabetes.

TRIAL REGISTRATION NUMBER

NCT02222350; Post-results.

Effects of solid-phase extraction of plasma in measuring gut metabolic hormones in fasted and fed blood of lean and diet-induced obese rats

Glucagon‐like peptide‐1 (GLP‐1), peptide YY (3‐36) [PYY(3‐36)], amylin, ghrelin, insulin, and leptin are thought to act as hormonal signals from periphery to brain to control food intake. Here, we determined the effects of solid‐phase extraction of plasma in measuring these hormones in blood of lean and diet‐induced obese rats. Individual enzyme‐linked immunoassays and a multiplex assay were used to measure active GLP‐1, total PYY, active amylin, active ghrelin, insulin, leptin, and total GIP in response to (1) addition of known amounts of the peptides to lean and obese plasma, (2) a large meal in lean and obese rats, and (3) intravenous infusions of anorexigenic doses of GLP‐1, PYY(3‐36), amylin, and leptin in lean rats. Extraction of lean and obese plasma prior to assays produced consistent recoveries across assays for GLP‐1, PYY, amylin, ghrelin, and insulin, reflecting losses inherent to the extraction procedure. Plasma extraction prior to assays generally revealed larger meal‐induced changes in plasma GLP‐1, PYY, amylin, ghrelin, and insulin in lean and obese rats. Plasma extraction and the multiplex assay were used to compare plasma levels of GLP‐1, PYY, and amylin after a large meal with plasma levels produced by IV infusions of anorexigenic doses of GLP‐1, PYY(3‐36), and amylin. Infusions produced dose‐dependent increases in plasma peptide levels, which were well above their postprandial levels. These results do not support the hypothesis that postprandial plasma levels of GLP‐1, PYY(3‐36), and amylin are sufficient to decrease food intake by an endocrine mechanism.

Efficacy of lixisenatide in patients with type 2 diabetes: A post hoc analysis of patients with diverse β-cell function in the GetGoal-M and GetGoal-S trials

AIMS

To evaluate the impact of β-cell function on the efficacy of lixisenatide, a once-daily prandial glucagon-like peptide-1 receptor agonist, in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

In this post hoc analysis, patients from the Phase 3 GetGoal-M and GetGoal-S clinical trials randomized to lixisenatide 20μg once daily were stratified into quartiles by baseline β-cell function, as measured by the secretory units of islet in transplantation (SUIT) index.

RESULTS

Patients (N=437) were distributed evenly among SUIT index quartiles 1 to 4 (lowest to highest β-cell function). Clinical outcomes improved from baseline across all SUIT quartiles; mean changes at week 24 were: glycated hemoglobin (HbA1c; % [mmol/mol]), -0.99 (-10.8), -0.87 (-9.5), -0.86 (-9.4), -0.83 (-9.1); and postprandial plasma glucose (PPG; mmol/L), -7.9, -5.6, -5.5, -4.3 (overall effect P<0.0001). Furthermore, postprandial glucagon was reduced in all SUIT quartiles, while insulinogenic index improved only in patients with higher baseline SUIT (overall effect P=0.0286). No severe symptomatic hypoglycemic events were reported.

CONCLUSIONS

Lixisenatide treatment resulted in reductions in HbA1c and PPG levels across all SUIT quartiles. This suggests that non-insulin-related actions of lixisenatide contribute to improved glycemic control in T2D.

A method for quantification of serum tenascin-X by nano-LC/MS/MS

BACKGROUND

Complete deficiency of an extracellular matrix tenascin-X (TNX) leads to a classical type of Ehlers-Danlos syndrome (EDS). TNX haploinsufficiency is a cause of hypermobility type of EDS. Human TNX is also present in a serum form (sTNX) with a molecular size of 140kDa. In this study, we established a method for quantification of sTNX using nano-liquid chromatography tandem mass spectrometry (LC/MS/MS) with selected/multiple reaction monitoring.

METHODS

Twelve abundant protein-depleted sera were reduced, alkylated, and digested with Lys-C and trypsin. Subsequently, the digests were fractionated by strong cation exchange chromatography. Optimal and validated transitions of precursor and product ions of the peptides from sTNX were developed on a triple quadrupole mass spectrometer.

RESULTS

Serum concentrations of sTNX of healthy individuals were quantified as an average of 144ng/ml. However, sTNX was not detected by this method in serum from a patient with a classical type of EDS in whom sTNX was not found by Western blot analysis. The limit of quantification (LOQ) of sTNX by nano-LC/MS/MS method was 2.8pg whereas the detection sensitivity of sTNX by Western blot analysis was 19pg. The nano-LC/MS/MS method is more sensitive than Western blot analysis.

CONCLUSIONS

The quantification method will be useful for diagnosis and risk stratification of EDS caused by TNX deficiency and haploinsufficiency.

Long-term safety and efficacy of a novel once-weekly oral trelagliptin as monotherapy or in combination with an existing oral antidiabetic drug in patients with type 2 diabetes mellitus: A 52-week open-label, phase 3 study

Aims/Introduction

Trelagliptin is a novel once‐weekly oral dipeptidyl peptidase‐4 inhibitor for type 2 diabetes mellitus that was first approved in Japan. We evaluated long‐term safety and efficacy of trelagliptin in Japanese patients with type 2 diabetes mellitus.

Materials and Methods

This was a phase 3, multicenter, open‐label study to evaluate long‐term safety and efficacy of trelagliptin. Patients with type 2 diabetes mellitus inadequately controlled despite diet/exercise or treatment with one of the existing oral antidiabetic drugs along with diet/exercise received trelagliptin 100 mg orally once weekly for 52 weeks as monotherapy or combination therapies. The primary end‐points were the safety variables, and the secondary end‐points were glycosylated hemoglobin and fasting plasma glucose.

Results

A total of 680 patients received the following antidiabetic therapies: trelagliptin monotherapy (n = 248), combination with a sulfonylurea (n = 158), a glinide (n = 67), an α‐glucosidase inhibitor (n = 65), a biguanide (n = 70), or a thiazolidinedione (n = 72). During the study, 79.8% of the patients experienced at least one adverse event for monotherapy, 87.3% for combination with a sulfonylurea, 77.6% for a glinide, 81.5% for an α‐glucosidase inhibitor, 64.3% for a biguanide, and 84.7% for a thiazolidinedione, respectively. Most of the adverse events were mild or moderate. The change in glycosylated hemoglobin from baseline at the end of the treatment period was −0.74 to −0.25% for each therapy.

Conclusions

Once‐weekly oral trelagliptin provides well‐tolerated long‐term safety and efficacy in both monotherapy and combination therapies in Japanese patients with type 2 diabetes mellitus.

Meal sequence and glucose excursion, gastric emptying and incretin secretion in type 2 diabetes: a randomised, controlled crossover, exploratory trial

AIMS/HYPOTHESIS

Investigation of dietary therapy for diabetes has focused on meal size and composition; examination of the effects of meal sequence on postprandial glucose management is limited. The effects of fish or meat before rice on postprandial glucose excursion, gastric emptying and incretin secretions were investigated.

METHODS

The experiment was a single centre, randomised controlled crossover, exploratory trial conducted in an outpatient ward of a private hospital in Osaka, Japan. Patients with type 2 diabetes (n = 12) and healthy volunteers (n = 10), with age 30-75 years, HbA1c 9.0% (75 mmol/mol) or less, and BMI 35 kg/m(2) or less, were randomised evenly to two groups by use of stratified randomisation, and subjected to meal sequence tests on three separate mornings; days 1 and 2, rice before fish (RF) or fish before rice (FR) in a crossover fashion; and day 3, meat before rice (MR). Pre- and postprandial levels of glucose, insulin, C-peptide and glucagon as well as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide were evaluated. Gastric emptying rate was determined by (13)C-acetate breath test involving measurement of (13)CO2 in breath samples collected before and after ingestion of rice steamed with (13)C-labelled sodium acetate. Participants, people doing measurements or examinations, and people assessing the outcomes were not blinded to group assignment.

RESULTS

FR and MR in comparison with RF ameliorated postprandial glucose excursion (AUC-15-240 min-glucose: type 2 diabetes, FR 2,326.6 ± 114.7 mmol/l × min, MR 2,257.0 ± 82.3 mmol/l × min, RF 2,475.6 ± 87.2 mmol/l × min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 1,419.8 ± 72.3 mmol/l × min, MR 1,389.7 ± 69.4 mmol/l × min, RF 1,483.9 ± 72.8 mmol/l × min) and glucose variability (SD-15-240 min-glucose: type 2 diabetes, FR 1.94 ± 0.22 mmol/l, MR 1.68 ± 0.18 mmol/l, RF 2.77 ± 0.24 mmol/l [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 0.95 ± 0.21 mmol/l, MR 0.83 ± 0.16 mmol/l, RF 1.18 ± 0.27 mmol/l). FR and MR also enhanced GLP-1 secretion, MR more strongly than FR or RF (AUC-15-240 min-GLP-1: type 2 diabetes, FR 7,123.4 ± 376.3 pmol/l × min, MR 7,743.6 ± 801.4 pmol/l × min, RF 6,189.9 ± 581.3 pmol/l × min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 3,977.3 ± 324.6 pmol/l × min, MR 4,897.7 ± 330.7 pmol/l × min, RF 3,747.5 ± 572.6 pmol/l × min [p < 0.05 for MR vs RF and MR vs FR]). FR and MR delayed gastric emptying (Time50%: type 2 diabetes, FR 83.2 ± 7.2 min, MR 82.3 ± 6.4 min, RF 29.8 ± 3.9 min [p < 0.05 for FR vs RF and MR vs RF]; healthy, FR 66.3 ± 5.5 min, MR 74.4 ± 7.6 min, RF 32.4 ± 4.5 min [p < 0.05 for FR vs RF and MR vs RF]), which is associated with amelioration of postprandial glucose excursion (AUC-15-120 min-glucose: type 2 diabetes, r = -0.746, p < 0.05; healthy, r = -0.433, p < 0.05) and glucose variability (SD-15-240 min-glucose: type 2 diabetes, r = -0.578, p < 0.05; healthy, r = -0.526, p < 0.05), as well as with increasing GLP-1 (AUC-15-120 min-GLP-1: type 2 diabetes, r = 0.437, p < 0.05; healthy, r = 0.300, p = 0.107) and glucagon (AUC-15-120 min-glucagon: type 2 diabetes, r = 0.399, p < 0.05; healthy, r = 0.471, p < 0.05). The measured outcomes were comparable between the two randomised groups.

CONCLUSIONS/INTERPRETATION

Meal sequence can play a role in postprandial glucose control through both delayed gastric emptying and enhanced incretin secretion. Our findings provide clues for medical nutrition therapy to better prevent and manage type 2 diabetes.

TRIAL REGISTRATION

UMIN Clinical Trials Registry UMIN000017434.

FUNDING

Japan Society for Promotion of Science, Japan Association for Diabetes Education and Care, and Japan Vascular Disease Research Foundation.

2015 White Paper on recent issues in bioanalysis: focus on new technologies and biomarkers (Part 2 – hybrid LBA/LCMS and input from regulatory agencies)

The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of over 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. It is once again a 5-day week long event – a full immersion bioanalytical week – specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches including the focus on biomarkers and immunogenicity. This 2015 White Paper encompasses recommendations that emerged from the extensive discussions held during the workshop, and is aimed at providing the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to advance scientific excellence, improve quality and deliver better regulatory compliance. Due to its length, the 2015 edition of this comprehensive White Paper has been divided into three parts. Part 2 covers the recommendations for hybrid LBA/LCMS and regulatory agencies’ inputs. Part 1 (small molecule bioanalysis using LCMS) and Part 3 (large molecule bioanalysis using LBA, biomarkers and immunogenicity) will be published in volume 7 of Bioanalysis, issues 22 and 24, respectively.

Long-term safety of once-daily lixisenatide in Japanese patients with type 2 diabetes mellitus: GetGoal-Mono-Japan

AIMS

This 76-week, open-label, parallel-group study assessed the long-term safety of once-daily lixisenatide monotherapy in Japanese patients with type 2 diabetes mellitus.

METHODS

Patients were randomized to receive lixisenatide in a 2-step or a 1-step dose-increase regimen. The primary objective was to assess the safety of lixisenatide at week 24 by a descriptive comparison of the 2- and 1-step groups.

RESULTS

As expected with treatment with a glucagon-like peptide-1 agonist, nausea was the most common treatment-emergent adverse event (2-step group: n=12/33 [36.4%] vs 1-step group: n=18/36 [50.0%] up to week 24). In total, 5/33 patients (15.2%; 2-step group) and 2/36 patients (5.6%; 1-step group) prematurely discontinued treatment up to week 24, mainly due to adverse events. Serious treatment-emergent adverse events occurred in 2/33 patients (6.1%; 2-step group) versus 0/36 patients (0%; 1-step group) up to week 24. Symptomatic hypoglycemia occurred in 2/33 patients (6.1%; 2-step group) versus 1/36 patients (2.8%; 1-step group) up to week 24, with no severe events reported. Glycated hemoglobin, fasting plasma glucose, and body weight were reduced from baseline at weeks 24 and 76.

CONCLUSION

In Japanese patients with type 2 diabetes mellitus, once-daily lixisenatide monotherapy was well tolerated, with less nausea with the 2-step regimen.

Multiplexed Quantification of Proglucagon-Derived Peptides by Immunoaffinity Enrichment and Tandem Mass Spectrometry after a Meal Tolerance Test

BACKGROUND

Proglucagon-derived peptides (PGDPs), which include glucagon-like peptide (GLP)-1, glucagon, and oxyntomodulin, are key regulators of glucose homeostasis and satiety. These peptide hormones are typically measured with immuno-based assays (e.g., ELISA, RIA), which often suffer from issues of selectivity.

METHODS

We developed a multiplexed assay for measuring PGDPs including GLP-1 (7-36) amide, GLP-1 (9-36) amide, glucagon, and oxyntomodulin by mass spectrometry and used this assay to examine the effect of a meal tolerance test on circulating concentrations of these hormones. Participants fasted overnight and were either given a meal (n = 8) or continued to fast (n = 4), with multiple blood collections over the course of 3 h. Plasma samples were analyzed by microflow immunoaffinity (IA)-LC-MS/MS with an isotope dilution strategy.

RESULTS

Assay performance characteristics were examined and established during analytical validation for all peptides. Intra- and interassay imprecision were found to be 2.2%-10.7% and 6.8%-22.5%, respectively. Spike recovery was >76%, and dilution linearity was established up to a 16-fold dilution. Immediately after the meal tolerance test, GLP-1 and oxyntomodulin concentrations increased and had an almost identical temporal relationship, and glucagon concentrations increased with a slight delay.

CONCLUSIONS

IA-LC-MS/MS was used for the simultaneous and selective measurement of PGDPs. This work includes the first indication of the physiological concentrations and modulation of oxyntomodulin after a meal.

Effects of Miglitol, Acarbose, and Sitagliptin on Plasma Insulin and Gut Peptides in Type 2 Diabetes Mellitus: A Crossover Study

INTRODUCTION

Both dipeptidyl peptidase-4 inhibitors and α-glucosidase inhibitors (α-GI) have been reported to change the incretin and insulin secretion. To examine the effects of acarbose, miglitol, and sitagliptin on glucose metabolism and secretion of gut peptides, we conducted a crossover study in patients with type 2 diabetes mellitus (T2DM).

METHODS

Eleven Japanese patients with T2DM underwent four meal tolerance tests with single administration of acarbose, miglitol, sitagliptin, or nothing. Fasting and postprandial plasma levels of glucose, insulin, glucagon, active glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), ghrelin, and des-acyl ghrelin were measured.

RESULTS

Early-phase insulin secretion was reduced following acarbose and miglitol, and the areas under the curve (AUC) of insulin at 180 min following acarbose and miglitol were significantly lower than sitagliptin. AUC of plasma glucose at 180 min after acarbose, miglitol, and sitagliptin tended to be lower than in controls, and plasma glucose levels at 30-60 min following miglitol were significantly lower than in controls. Plasma glucagon, ghrelin, and des-acyl ghrelin levels did not differ among the four conditions. Postprandial plasma active GLP-1 levels and AUC of GLP-1 increased significantly in both the sitagliptin and miglitol groups compared to control. Postprandial plasma total GIP levels increased following sitagliptin but decreased after acarbose and miglitol. Changes in incretin levels tended to be greater with miglitol than acarbose.

CONCLUSION

These results showed that sitagliptin and α-GIs, miglitol more so than acarbose, improved hyperglycemia in patients with T2DM after single administration, and had different effects on insulin and incretin secretion.

TRIAL REGISTRATION

UMIN-CTR number, UMIN000009981.

β cell dysfunction versus insulin resistance in the pathogenesis of type 2 diabetes in East Asians

Type 2 diabetes (T2DM) is one of the most serious global health problems and is mainly a result of the drastic increase in East Asia, which includes over a fourth of the global diabetes population. Lifestyle factors and ethnicity are two determinants in the etiology of T2DM, and lifestyle changes such as higher fat intake and less physical activity link readily to T2DM in East Asians. It is widely recognized that T2DM in East Asians is characterized primarily by β cell dysfunction, which is evident immediately after ingestion of glucose or meal, and less adiposity compared to the disease in Caucasians. These pathophysiological differences have an important impact on therapeutic approaches. Here, we revisit the pathogenesis of T2DM in light of β cell dysfunction versus insulin resistance in East Asians and discuss ethnic differences in the contributions of insulin secretion and insulin resistance, together with incretin secretin and action, to glucose intolerance.

Early phase glucagon and insulin secretory abnormalities, but not incretin secretion, are similarly responsible for hyperglycemia after ingestion of nutrients

AIMS

Hypersecretion of glucagon and reduced insulin secretion both contribute to hyperglycemia in type 2 diabetes (T2DM). However, the relative contributions of impaired glucagon and insulin secretions in glucose excursions at the various stages of T2DM development remain to be determined.

METHODS

The responses of glucagon and insulin as well as those of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were examined before and after ingestion of glucose or mixed meal in Japanese subjects with normal or impaired glucose tolerance (NGT and IGT) and in non-obese, untreated T2DM of short duration.

RESULTS

In OGTT, T2DM showed a rise in glucagon at 0-30 min, unlike NGT and IGT, along with reduced insulin. In MTT, all three groups showed a rise in glucagon at 0-30 min, with that in T2DM being highest, while T2DM showed a significant reduction in insulin. Linear regression analyses revealed that glucose area under the curve (AUC)0-120 min was associated with glucagon-AUC0-30 min and insulin-AUC0-30 min in both OGTT and MTT. Total and biologically intact GIP and GLP-1 levels were similar among the three groups.

CONCLUSIONS

Disordered early phase insulin and glucagon secretions but not incretin secretion are involved in hyperglycemia after ingestion of nutrients in T2DM of even a short duration.

Efficacy and safety of sitagliptin added to insulin in Japanese patients with type 2 diabetes: the EDIT randomized trial

Aims

To clarify the efficacy and safety of adding sitagliptin to insulin therapy in Japanese patients with suboptimally controlled type 2 diabetes (T2DM).

Study Design and Methods

This was a 24-week, prospective, randomized, open-labeled, controlled trial. Patients with T2DM who were suboptimally controlled despite receiving at least twice daily injection of insulin were enrolled in the study. The patients were randomized to continuation of insulin treatment (Insulin group) or addition of sitagliptin 50 to 100 mg daily to insulin treatment (Ins+Sita group). The primary outcome was change in HbA1c at week 24.

Results

Adding sitagliptin to insulin significantly reduced HbA1c from 7.9 ± 1.0% at baseline to 7.0 ± 0.8% at week 24 (P <0.0001), while there was no significant change in HbA1c in the Insulin group (7.8 ± 0.7% vs. 7.8 ± 1.1%, P = 0.32). The difference in HbA1c reduction between the groups was 0.9% (95% confidence interval, 0.4 to 1.5, P = 0.01). There was no significant weight gain in either group. Incidence of hypoglycemia was significantly reduced in the Ins+Sita group compared with the Insulin group. Treatment satisfaction was improved in the Ins+Sita group. Baseline HbA1c level and beta cell function were associated with the magnitude of reduction in HbA1c in the Ins+Sita group.

Conclusion

Adding sitagliptin to insulin reduced HbA1c without weight gain or increase in hypoglycemia, and improved treatment satisfaction in Japanese patients with T2DM who were suboptimally controlled despite at least twice daily injection of insulin.

Trial Registration

The University Hospital Medical Information Network (UMIN) Clinical Trials Registry UMIN000004678

Once-weekly trelagliptin versus daily alogliptin in Japanese patients with type 2 diabetes: a randomised, double-blind, phase 3, non-inferiority study

BACKGROUND

Trelagliptin is a novel once-weekly oral DPP-4 inhibitor. We assessed the efficacy and safety of trelagliptin versus the daily oral DPP-4 inhibitor alogliptin in Japanese patients with type 2 diabetes.

METHODS

We did a randomised, double-blind, active-controlled, parallel-group, phase 3, non-inferiority study at 26 sites in Japan. We included individuals with type 2 diabetes inadequately controlled by diet and exercise. We randomly assigned patients (2:2:1) to receive trelagliptin (100 mg) once per week, alogliptin (25 mg) once per day, or placebo for 24 weeks. Randomisation was done electronically and independently from the study with permuted blocks of ten patients. Patients and clinicians were masked to group assignment. Patients in the trelagliptin group were given trelagliptin once a week and oral alogliptin placebo every day, whereas patients in the alogliptin group were given oral trelagliptin placebo once a week and oral alogliptin every day (double-dummy design). Patients in the placebo group were given an oral alogliptin placebo once a day and an oral trelagliptin placebo once a week. Our primary outcome was between-groups difference in change in HbA1c concentration from baseline to the end of treatment. The non-inferiority margin was 0·4%. Our analysis included all patients who were randomised and received at least one dose of study drug. The study is registered with ClinicalTrials.gov, number NCT01632007.

FINDINGS

Between May 26, 2012, and Nov 20, 2012, we enrolled 357 patients. 243 patients were included in the analysis (101 for trelagliptin, 92 for alogliptin, and 50 for placebo). In the primary analysis, the least squares mean change in HbA1c concentration was -0·33% in the trelagliptin group (SE 0·059) and -0·45% in the alogliptin group (0·061) based on the ANCOVA model. The least squares mean difference (trelagliptin minus alogliptin) of change from baseline in HbA1c concentration was 0·11% (95% CI -0·054 to 0·281). Trelagliptin was non-inferior to alogliptin. Both active groups had significantly reduced mean HbA1c concentrations at end of treatment compared with placebo (p<0·0001). The frequency of adverse events was similar between groups. No hypoglycaemia was reported with trelagliptin and the drug was well tolerated.

INTERPRETATION

The once-weekly DPP-4 inhibitor trelagliptin showed similar efficacy and safety to alogliptin once daily in Japanese patients with type 2 diabetes. Trelagliptin could be a useful new antidiabetes drug that needs to be given once a week.

FUNDING

Takeda Pharmaceutical Company.

Addition of sitagliptin or metformin to insulin monotherapy improves blood glucose control via different effects on insulin and glucagon secretion in hyperglycemic Japanese patients with type 2 diabetes

This study aimed to explore the effects of the dipeptidyl peptidase-4 inhibitor sitagliptin and the biguanide metformin on the secretion of insulin and glucagon, as well as incretin levels, in Japanese subjects with type 2 diabetes mellitus poorly controlled with insulin monotherapy. This was a single-center, randomized, open-label, parallel group study, enrolling 25 subjects. Eleven patients (hemoglobin A1c [HbA1c] 8.40 ± 0.96%) and 10 patients (8.10 ± 0.54%) on insulin monotherapy completed 12-week treatment with sitagliptin (50 mg) and metformin (750 mg), respectively. Before and after treatment, each subject underwent a meal tolerance test. The plasma glucose, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), C-peptide, and glucagon responses to a meal challenge were measured. HbA1c reductions were similar in patients treated with sitagliptin (0.76 ± 0.18%) and metformin (0.77 ± 0.17%). In the sitagliptin group, glucose excursion during a meal tolerance test was reduced and accompanied by elevations in active GLP-1 and active GIP concentrations. C-peptide levels were unaltered despite reduced glucose responses, while glucagon responses were significantly suppressed (-7.93 ± 1.95% of baseline). In the metformin group, glucose excursion and incretin responses were unaltered. C-peptide levels were slightly increased but glucagon responses were unchanged. Our data indicate that sitagliptin and metformin exert different effects on islet hormone secretion in Japanese type 2 diabetic patients on insulin monotherapy. A glucagon suppressing effect of sitagliptin could be one of the factors improving blood glucose control in patients inadequately controlled with insulin therapy.

Teneligliptin improves glycemic control with the reduction of postprandial insulin requirement in Japanese diabetic patients

Teneligliptin is a novel peptidomimetic-chemotype prolylthiazolidine-based inhibitor of dipeptidyl peptidase-4 (DPP-4). The aim of this study was to evaluate the effects of teneligliptin on 24 h blood glucose control and gastrointestinal hormone responses to a meal tolerance test, and to investigate the glucose-lowering mechanisms of teneligliptin. Ten patients with type 2 diabetes mellitus (T2DM) were treated for 3 days with teneligliptin (20 mg/day). Postprandial profiles for glucose, insulin, glucagon, active glucagon-like peptide-1 (GLP-1), active glucose-dependent insulinotropic polypeptide (GIP), ghrelin, des-acyl ghrelin, and 24 h glycemic fluctuations were measured via continuous glucose monitoring for 4 days. Once daily teneligliptin administration for 3 days significantly lowered postprandial and fasting glucose levels. Significant elevations of fasting and postprandial active GLP-1 and postprandial active GIP levels were observed. Teneligliptin lowered postprandial glucose elevations, 24 h mean blood glucose levels, standard deviation of 24 h glucose levels and mean amplitude of glycemic excursions (MAGE) without hypoglycemia. Serum insulin levels in the fasting state and 30 min after a meal were similar before and after teneligliptin treatment; however significant reductions at 60 to 180 min after treatment were observed. A significant elevation in early-phase insulin secretion estimated by insulinogenic and oral disposition indices, and a significant reduction in postprandial glucagon AUC were observed. Both plasma ghrelin and des-acyl ghrelin levels were unaltered following teneligliptin treatment. Teneligliptin improved 24 h blood glucose levels by increasing active incretin levels and early-phase insulin secretion, reducing the postprandial insulin requirement, and reducing glucagon secretion. Even short-term teneligliptin treatment may offer benefits for patients with T2DM.

Incretin physiology and pathophysiology from an Asian perspective

Incretin hormones, such as glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1, are secreted on oral nutrient ingestion and regulate postprandial glucose homeostasis by conveying the signal of intestinal glucose flux. In East Asians, the secretion of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 is not reduced in type 2 diabetes relative to normal glucose tolerance. Although the incretin effect is blunted in European patients with type 2 diabetes, a few East Asian studies showed no difference in the incretin effect between type 2 diabetes and normal glucose tolerance. Interestingly, the glucose-lowering efficacy of dipeptidyl peptidase-4 inhibitors or glucagon-like peptide-1 receptor agonists was reported to be greater in Asians than in non-Asians. The difference in the treatment responses could be ascribed to a different pathophysiology of type 2 diabetes (lower insulin secretory function and less insulin resistance), lower body mass index, different genetic makeups, preserved incretin effect and different food compositions in East Asians compared with other ethnic groups. Based on the currently available data, incretin-based therapies appear to be safe and well tolerated in East Asians. Nevertheless, continuous pharmacovigilance is required. The characteristics of incretin biology and treatment responses to incretin-based therapies should be considered in developing ethnicity-specific treatment guidelines and making patient-centered decisions for patients with type 2 diabetes.

Additive effects of miglitol and anagliptin on insulin-treated type 2 diabetes mellitus: a case study

The aim of this case study was to examine the efficacy of a dipeptidyl peptidase-4 inhibitor (anagliptin) and an α-glucosidase inhibitor (miglitol) when added to ongoing insulin treatment in patients with type 2 diabetes mellitus. Continuous glucose monitoring was performed in four Japanese insulin-treated inpatients with type 2 diabetes. Baseline data were collected on day 1. Miglitol was administered on days 2 and 3. On day 4, miglitol and anagliptin were coadministered before breakfast. On days 1, 3, and 5, blood was drawn for plasma glucose, serum C-peptide, plasma glucagon, total and active glucagon-like peptide-1 (GLP-1), and total and active glucose-dependent insulinotropic peptide (GIP) measurements. Coadministration of anagliptin with miglitol resulted in additional improvements in glycemic control over the entire day in three of the four patients. The C-peptide, glucagon, and total and active GLP-1 and GIP responded differently to the medications for each patient, suggesting interindividual differences in hormonal responses, which may be complicated by multifactorial effects.

Effects of miglitol, sitagliptin, and initial combination therapy with both on plasma incretin responses to a mixed meal and visceral fat in over-weight Japanese patients with type 2 diabetes. "the MASTER randomized, controlled trial"

AIM

To assess changes in circulating incretin levels and body fat compositions with initial combination therapy with α-glucosidase inhibitor and dipeptidyl peptidase-4 inhibitor in patients with type 2 diabetes (T2D).

METHODS

In this multicenter open-label 24-week trial, Japanese over-weight (BMI ≥ 25 kg/m(2)) patients with T2D not taking medication or taking metformin and/or sulfonylurea were randomly assigned to receive either 50mg of miglitol three times a day (M, n=14), 50mg of sitagliptin once a day (S, n=14), or a combination of both (M+S, n=13). Changes in plasma incretin levels during a meal tolerance test (MTT) and body fat composition with impedance method were evaluated.

RESULTS

During MTT, postprandial plasma glucose levels decreased more after M+S than after M or S, and postprandial serum insulin levels decreased significantly after M and M+S whereas they increased after S. After M, active gastric inhibitory polypeptide (aGIP) decreased significantly at 30 min despite a significant increase at 120 min. After S, aGIP levels increased significantly throughout the MTT. After M+S, aGIP increased significantly at 0 and 120 min despite of significant decrease at 30 min. M+S further enhanced postprandial active glucagon-like peptide-1 levels during MTT than S did. Total body fat mass decreased significantly after M and M+S. Visceral fat mass decreased significantly only after M+S. Serum adiponectin increased significantly only after M+S.

CONCLUSIONS

In over-weight patients with T2D, M+S may have a beneficial effect on adiposity with relation to these different effects on two incretins.

Defining the role of GLP-1 receptor agonists for individualized treatment of Type 2 diabetes

With the advent of dipeptidyl peptidase (DPP)-4 inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) over the past decade, incretin therapy has become established as an important treatment strategy for Type 2 diabetes mellitus (T2DM), with an efficacy and safety profile distinct from that of other anti-hyperglycemic agents. However, our understanding of the optimal clinical use of incretins remains incomplete. This review focuses on the use of GLP-1 RAs in the treatment of T2DM, with reference to the differing dominant mechanisms of action between short- and long-acting GLP-1 RAs and the clinical implications of this difference. The role of GLP-1 and the effects of GLP-1 RAs in various organs other than the pancreas will also be discussed.

Efficacy and safety of lixisenatide in Japanese patients with type 2 diabetes mellitus inadequately controlled by sulfonylurea with or without metformin: Subanalysis of GetGoal-S

Aims/Introduction

This was a subanalysis of Japanese patients included in the glucagon-like peptide-1 receptor agonist AVE0010 in patients with type 2 diabetes mellitus for glycemic control and safety evaluation (GetGoal-S) study – a 24-week, randomized, placebo-controlled study of lixisenatide in patients with type 2 diabetes mellitus inadequately controlled by sulfonylurea with or without metformin.

Materials and Methods

In GetGoal-S, 127 Japanese patients received the once-daily prandial glucagon-like peptide-1 receptor agonist lixisenatide 20 μg/day or a matching placebo. The primary outcome was change in glycated hemoglobin.

Results

At week 24, lixisenatide significantly reduced mean glycated hemoglobin (least squares mean difference vs the placebo −1.1% [12 mmol/mol, P < 0.0001]), and significantly more lixisenatide patients reached glycated hemoglobin targets of <7% (53 mmol/mol) and ≤6.5% (48 mmol/mol) vs the placebo. Lixisenatide produced statistically significant reductions in 2-h postprandial plasma glucose (least squares mean difference vs the placebo −8.51 mmol/L, P < 0.0001) and glucose excursion vs the placebo, and significantly reduced fasting plasma glucose (least squares mean difference vs the placebo −0.65 mmol/L, P = 0.0454). Bodyweight decreased with both lixisenatide and the placebo (least squares mean change −1.12 kg for lixisenatide, −1.02 kg for placebo). The overall incidence of adverse events was similar for lixisenatide and the placebo (84.2 and 82.4%, respectively), the most frequent being gastrointestinal disorders (52.6% for lixisenatide vs 29.4% for placebo). The incidence of symptomatic hypoglycemia was higher with lixisenatide vs the placebo (17.1 and 9.8%, respectively), with no cases of severe symptomatic hypoglycemia in either group.

Conclusions

In the Japanese subpopulation of the GetGoal-S study, lixisenatide produced a significant and clinically relevant improvement in glycated hemoglobin, with a pronounced improvement in postprandial plasma glucose, and a good safety and tolerability profile.

Effects of sitagliptin on ectopic fat contents and glucose metabolism in type 2 diabetic patients with fatty liver: A pilot study

Aims/Introduction

Recent data have shown that ectopic fat accumulation in the liver worsens hepatic glucose metabolism, suggesting that fatty liver in patients with type 2 diabetes is a therapeutic target. Glucagon-like peptide (GLP)-1 improves fatty liver, but the effect of dipeptidyl peptidase-4 inhibitor on fatty liver is still unclear. The present pilot study determined the effects of 12-week treatment with sitagliptin, a dipeptidyl peptidase-4 inhibitor, on liver fat content in type 2 diabetes with fatty liver. We also evaluated intramyocellular lipid (IMCL) and glucose kinetics during oral glucose tolerance test (OGTT) before and after the treatment.

Materials and Methods

The study participants were seven type 2 diabetes patients with fatty liver who were studied at baseline and 12 weeks after sitagliptin treatment. Intrahepatic lipid (IHL) and IMCL were assessed by ¹H magnetic resonance spectroscopy. Glucose kinetics was assessed during double-tracer OGTT (U-[¹³C]-glucose orally and 6,6-[²H₂]-glucose intravenously).

Results

Sitagliptin significantly reduced glycated hemoglobin (from 7.1 ± 0.2 to 6.5 ± 0.3%, P < 0.005), but had no effects on IHL and IMCL. The glucose level diminished, whereas GLP-1 concentration increased during OGTT at the end of treatment. These changes were not accompanied by significant changes in insulin or glucagon levels. However, long-term sitagliptin treatment partially decreased the rate of appearance of oral glucose during OGTT, but did not affect endogenous glucose production or the rate of disappearance.

Conclusions

It was found that 12-week sitagliptin treatment improved glycated hemoglobin and glucose excursion during OGTT in type 2 diabetes with fatty liver, independent of changes in lipid accumulation in the liver. This trial was registered with the Japan Clinical Trials Registry (UMIN-CTR000005666).

Pharmacodynamics of the glucagon-like peptide-1 receptor agonist lixisenatide in Japanese and Caucasian patients with type 2 diabetes mellitus poorly controlled on sulphonylureas with/without metformin

AIMS

The PDY6797 study evaluated efficacy, safety and pharmacodynamics of lixisenatide in Japanese and Caucasian patients with type 2 diabetes mellitus (T2DM) insufficiently controlled with sulphonylureas with/without metformin.

METHODS

This randomized, double-blind, placebo-controlled trial comprised a single-dose assessment of lixisenatide 5 and 10 µg, and a 5- to 6-week repeated dose-escalation assessment of lixisenatide 5 to 30 µg once (QD) or twice daily (BID). The primary endpoint was change in postprandial plasma glucose (PPG) area under the curve (AUC)[0:29-4:30 h] after a standardized breakfast at the highest tolerated lixisenatide dose. Change from baseline in glycated haemoglobin (HbA1c), 2-h PPG and fasting plasma glucose (FPG) were assessed, as were adverse events.

RESULTS

Change from baseline in PPG AUC[0:29-4:30 h] with lixisenatide QD and BID was significantly greater than placebo (p < 0.0001 for all study populations), with particularly prominent effects in Japanese patients. Greater reductions in PPG AUC[0:29-4:30 h] were seen with lixisenatide QD versus BID, while the totality of evidence suggested that the lixisenatide 20 µg dose was optimal. In the overall population, changes from baseline for 2-h PPG, HbA1c and FPG were significant with lixisenatide QD and BID versus placebo (p < 0.01 for all). Lixisenatide was well tolerated.

CONCLUSIONS

Lixisenatide significantly reduced PPG AUC[0:29-4:30 h] versus placebo at the highest well-tolerated dose in patients with T2DM treated with sulphonylureas with/without metformin and had a good safety and tolerability profile. Japanese patients experienced particular benefits with lixisenatide in terms of reductions in PPG excursions.

Exploratory trial of intranasal administration of glucagon-like peptide-1 in Japanese patients with type 2 diabetes

OBJECTIVE

This study aimed to assess the efficacy and safety of our newly developed nasal glucagon-like peptide-1 (GLP-1) compound and injector.

RESEARCH DESIGN AND METHODS

Twenty-six patients with type 2 diabetes were enrolled in this double-blind placebo-controlled study. The nasal compound containing 1.2 mg of human GLP-1 (7-36) amide or placebo was administered immediately before every meal for 2 weeks.

RESULTS

The plasma peak concentration of active GLP-1 was 47.2 pmol/L, and its Tmax was 8.1 min. The early phase of insulin and glucagon secretion were recovered and suppressed, respectively, in the GLP-1 group. Glycoalbumin levels became significantly lower and 1,5-anhydroglucitol levels significantly higher after GLP-1 administration. No marked adverse events were observed after using nasal GLP-1.

CONCLUSIONS

The newly developed nasal GLP-1 compound may be a potential treatment for type 2 diabetes. The long-term application of the drug should be evaluated in future trials.

Lixisenatide as add-on therapy to basal insulin

Many patients with type 2 diabetes mellitus do not achieve target glycosylated hemoglobin A1c levels despite optimally titrated basal insulin and satisfactory fasting plasma glucose levels. Current evidence suggests that HbA1c levels are dictated by both basal glucose and postprandial glucose levels. This has led to a consensus that postprandial glucose excursions contribute to poor glycemic control in these patients. Lixisenatide is a once-daily, prandial glucagon-like peptide 1 (GLP-1) receptor agonist with a four-fold affinity for the GLP-1 receptor compared with native GLP-1. Importantly, lixisenatide causes a significant delay in gastric emptying time, an important determinant of the once-daily dosing regimen. An exendin-4 mimetic with six lysine residues removed at the C-terminal, lixisenatide has pronounced postprandial glucose-lowering effects, making it a novel incretin agent for use in combination with optimally titrated basal insulin. Lixisenatide exerts profound effects on postprandial glucose through established mechanisms of glucose-dependent insulin secretion and glucagon suppression in combination with delayed gastric emptying. This review discusses the likely place that lixisenatide will occupy in clinical practice, given its profound effects on postprandial glucose and potential to reduce glycemic variability.

Enhanced glucagon-like peptide-1 secretion in a patient with glucagonoma: implications for glucagon-like peptide-1 secretion from pancreatic α cells in vivo

We examined GLP-1 secretion from the pancreas of a patient with glucagonoma and pancreatic resection by measuring GLP-1 after meal ingestion or selective arterial calcium injection, and immunohistochemical analysis. Our findings support the notion that GLP-1 is secreted from pancreatic α cells in humans.

Impact of incretin on early-phase insulin secretion and glucose excursion

This study investigated the impact of incretin on early-phase insulin secretion and glucose excursion. The normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) groups included 16, 8, and 19 subjects, respectively. Subjects underwent continuous glucose monitoring for 3 days, followed by an oral glucose tolerance test. Plasma glucose, insulin, glucagon, total glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide-l (GLP-1) levels were measured at 30-min increments for 2 h after glucose intake. Differences with P < 0.05 were considered statistically significant. The area under the curve (AUC) of total GIP (120-min GIP-AUC) of the T2DM group was significantly lower than those of the NGT and IGT groups. The 120-min GLP-1-AUC of the NGT group was significantly larger than those of the T2DM and IGT groups. The early-phase insulin secretion index (ΔI30/ΔG30) of the T2DM group was significantly lower than those of the NGT and IGT groups. Mean amplitudes of glycemic excursions (MAGEs) went in the order of NGT < IGT < T2DM (P < 0.01, IGT vs. NGT; P < 0.001, T2DM vs. IGT). The 120-min GIP-AUC was negatively correlated with MAGE (r = -0.464), but uncorrelated with ΔI30/ΔG30. The 120-min GLP-1-AUC was positively correlated with ΔI30/ΔG30 (r = 0.580), but negatively correlated with MAGE (r = -0.606). Incretin may ameliorate glucose excursions, and GLP-1 may exert them by promoting early-phase insulin secretion. No correlation was observed between GIP secretion and early-phase insulin secretion.

First human dose-escalation study with remogliflozin etabonate, a selective inhibitor of the sodium-glucose transporter 2 (SGLT2), in healthy subjects and in subjects with type 2 diabetes mellitus

Background

Remogliflozin etabonate (RE) is the prodrug of remogliflozin, a selective inhibitor of the renal sodium-dependent glucose transporter 2 (SGLT2), which could increase urine glucose excretion (UGE) and lower plasma glucose in humans.

Methods

This double-blind, randomized, placebo-controlled, single-dose, dose-escalation, crossover study is the first human trial designed to evaluate safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of RE. All subjects received single oral doses of either RE or placebo separated by approximately 2 week intervals. In Part A, 10 healthy subjects participated in 5 dosing periods where they received RE (20 mg, 50 mg, 150 mg, 500 mg, or 1000 mg) or placebo (4:1 active to placebo ratio per treatment period). In Part B, 6 subjects with type 2 diabetes mellitus (T2DM) participated in 3 dose periods where they received RE (50 mg and 500 mg) or placebo (2:1 active to placebo per treatment period). The study protocol was registered with the NIH clinical trials data base with identifier NCT01571661.

Results

RE was generally well-tolerated; there were no serious adverse events. In both populations, RE was rapidly absorbed and converted to remogliflozin (time to maximum plasma concentration [C_max;T_max] approximately 1 h). Generally, exposure to remogliflozin was proportional to the administered dose. RE was rapidly eliminated (mean T_½ of ~25 min; mean plasma T_½ for remogliflozin was 120 min) and was independent of dose. All subjects showed dose-dependent increases in 24-hour UGE, which plateaued at approximately 200 to 250 mmol glucose with RE doses ≥150 mg. In T2DM subjects, increased plasma glucose following OGTT was attenuated by RE in a drug-dependent fashion, but there were no clear trends in plasma insulin. There were no apparent effects of treatment on plasma or urine electrolytes.

Conclusions

The results support progression of RE as a potential treatment for T2DM.

Trial registration

ClinicalTrials.gov NCT01571661

Effects of thirty-times chewing per bite on secretion of glucagon-like peptide-1 in healthy volunteers and type 2 diabetic patients

Glucagon-like peptide 1 (GLP-1) is secreted from the small intestine to the blood in response to glucose intake during a meal; however, it is not known whether mastication affects GLP-1 secretion. Here, we examined the relationship between mastication and GLP-1 secretion, along with postprandial blood glucose and insulin concentrations. We compared the levels of blood glucose, serum insulin, and plasma active GLP-1 concentrations after young healthy volunteers ate a test meal either by usual eating (control) or in one of three specified ways: 1. unilateral chewing, 2. quick eating, 3. 30-times chewing per bite. Ten volunteers participated in each of the three groups. Plasma active GLP-1 concentrations did not change by unilateral chewing or quick eating, but did increase by the third method, without affecting the concentrations of blood glucose or serum insulin. Next, we tested whether 30-times chewing per bite increased plasma active GLP-1 concentrations in 15 patients with type 2 diabetes mellitus, but there was no difference in results between usual eating and 30-times chewing per bite. This is a pilot trial with a small number of subjects, but is the first study to investigate the relationships between various styles of mastication and the GLP-1 secretion in young healthy volunteers and type 2 diabetic patients.

Effect of the addition of sitagliptin and miglitol on insulin-treated type 2 diabetes

INTRODUCTION

To examine the efficacy of sitagliptin and miglitol when added to ongoing insulin treatment in a patient with type 2 diabetes who had undergone partial gastrectomy.

METHODS

Continuous glucose monitoring (CGM) was performed and either sitagliptin or miglitol, or both, were added to fixed-dose insulin therapy. Blood was drawn at 0, 30, 60, and 120 min after breakfast, and C-peptide, glucagon, glucagon-like peptide (GLP)-1, and glucose-dependent insulinotropic peptide (GIP) were measured.

RESULTS

CGM showed that compared to insulin alone, the addition of either sitagliptin or miglitol, or both, to insulin achieved better glucose control. Compared to insulin alone, early postprandial increments in plasma C-peptide levels and suppressed glucagon levels were observed when sitagliptin was added. Glucagon suppression was even more prominent when both sitagliptin and miglitol were added. Compared to insulin alone, GLP-1 levels were higher during the early postprandial stage when sitagliptin or miglitol was added and even higher when both were added. GIP levels decreased when sitagliptin or miglitol, or both, were added to insulin therapy.

CONCLUSION

The authors showed that the addition of sitagliptin or miglitol, or both, was effective in this insulin-treated patient with diabetes who had undergone gastrectomy.

Efficacy and safety of alogliptin added to metformin in Japanese patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial with an open-label, long-term extension study

AIMS

To evaluate the efficacy and safety of alogliptin added to metformin versus metformin monotherapy in Japanese patients with type 2 diabetes who achieved inadequate glycaemic control on metformin (500 or 750 mg/day) + diet/exercise.

METHODS

In a randomized, double-blind trial, 288 patients with type 2 diabetes mellitus T2DM received either 12.5 or 25 mg alogliptin once daily + metformin or placebo + metformin for 12 weeks. Thereafter, 276 patients continued on one of the two alogliptin dosages + metformin in an open-label extension for 40 weeks. The primary efficacy endpoint in the randomized, double-blind phase was the change in HbA1c from baseline (week 0) to the end of treatment (week 12). The primary endpoint during the long-term extension phase was adverse events.

RESULTS

After 12 weeks both dosages of alogliptin + metformin produced significantly greater changes from baseline in HbA1c than placebo (metformin monotherapy: with changes in LS means - 0.55 and - 0.64% vs. 0.22%, respectively; p < 0.0001). Incidences of adverse effects were comparable between groups, with no increases in hypoglycaemia. Over 52 weeks, there were no safety or tolerability concerns with alogliptin when added to metformin.

CONCLUSIONS

Alogliptin 12.5 and 25 mg once daily was safe and effective when added to metformin (500 or 750 mg/day) in Japanese patients with inadequately controlled type 2 diabetes on metformin alone.

Randomized, double-blind, placebo-controlled trial of the once-daily GLP-1 receptor agonist lixisenatide in Asian patients with type 2 diabetes insufficiently controlled on basal insulin with or without a sulfonylurea (GetGoal-L-Asia)

AIMS

To assess the efficacy and safety of once-daily lixisenatide versus placebo in Asian patients with type 2 diabetes insufficiently controlled on basal insulin ± sulfonylurea.

METHODS

In this 24-week, randomized, double-blind, placebo-controlled, parallel-group, multicentre study, participants (mean baseline HbA(1c) 8.53%) from Japan, Republic of Korea, Taiwan and the Philippines received lixisenatide (n = 154) or placebo (n = 157) in a stepwise dose increase to 20 µg once daily. The primary endpoint was HbA(1c) change from baseline to week 24.

RESULTS

Once-daily lixisenatide significantly improved HbA(1c) versus placebo (LS mean difference vs. placebo = -0.88% [95%CI= -1.116, -0.650]; p < 0.0001), and allowed more patients to achieve HbA(1c) <7.0% (35.6 vs. 5.2%) and ≤ 6.5% (17.8 vs. 1.3%). Lixisenatide also significantly improved 2-h postprandial plasma glucose and glucose excursion, average 7-point self-monitored blood glucose and fasting plasma glucose. Lixisenatide was well tolerated; 86% of patients on lixisenatide completed the study versus 92% on placebo. Ten (6.5%) lixisenatide and 9 (5.7%) placebo patients experienced serious adverse events. More lixisenatide patients [14 (9.1%)] discontinued for adverse events versus placebo [5 (3.2%)], mainly with gastrointestinal causes. Nausea and vomiting were reported in 39.6 and 18.2% of patients on lixisenatide versus 4.5 and 1.9% on placebo. Symptomatic hypoglycaemia was more frequent with lixisenatide (42.9%) versus placebo (23.6%), but was similar between groups (32.6 vs. 28.3%, respectively), in those not receiving sulfonylureas. No severe hypoglycaemia was reported.

CONCLUSIONS

In an Asian type 2 diabetes population insufficiently controlled by basal insulin  ±  sulfonylurea, once-daily lixisenatide significantly improved glycaemic control, with a pronounced postprandial effect, and was well tolerated.

Efficacy and safety of alogliptin added to sulfonylurea in Japanese patients with type 2 diabetes: A randomized, double-blind, placebo-controlled trial with an open-label, long-term extension study

Aims/Introduction

To evaluate the efficacy and safety of alogliptin added to treatment with glimepiride.

Materials and Methods

This multicenter, randomized, double‐blind, parallel‐group, 24‐week (12‐week observation and 12‐week treatment) study compared alogliptin 12.5 or 25 mg in combination with glimepiride (1–4 mg/day) vs placebo added to glimepiride monotherapy in Japanese patients with type 2 diabetes who had poor glycemic control despite treatment with diet and exercise plus a sulfonylurea. The primary end‐point was a change in glycated hemoglobin (HbA_1c) from baseline. A 40‐week open‐label extension study evaluated the long‐term safety and efficacy of the combination.

Results

Alogliptin 12.5 or 25 mg in combination with glimepiride significantly decreased HbA_1c compared with glimepiride monotherapy after 12 weeks' treatment (−0.59, −0.65 and 0.35%, respectively; P < 0.0001 for both combination groups vs glimepiride monotherapy). Alogliptin 12.5 and 25 mg combination therapy was also associated with significantly higher responder rates (HbA_1c <6.9%: 9.6% and 7.7%, HbA_1c <7.4%: 29.8% and 34.6%) compared with glimepiride monotherapy (HbA_1c <6.9%: 0%, HbA_1c <7.4%: 3.9%). The incidence of adverse events was comparable between glimepiride monotherapy and alogliptin combination treatment, with most reported adverse events being mild in severity. In the extension study, the incidence of adverse events was comparable between the combination groups, with the majority of adverse events being mild.

Conclusions

Once‐daily alogliptin was effective and generally well tolerated when given as add‐on therapy to glimepiride in Japanese patients with type 2 diabetes who had inadequate glycemic control on sulfonylurea plus lifestyle measures. Clinical benefits were maintained for 52 weeks. This trial was registered with ClinicalTrials.gov (double‐blind study no. NCT01318083; long‐term study no. NCT01318135).