Retrospective analysis of safety and efficacy of liraglutide monotherapy and sulfonylurea-combination therapy in Japanese type 2 diabetes: Association of remaining β-cell function and achievement of HbA1c target one year after initiation

PIONEER REAL Japan: Primary results from a multicenter, prospective, real-world study of oral semaglutide in adults with type 2 diabetes in Japanese clinical practice

AIMS/INTRODUCTION

PIONEER REAL Japan was a non-interventional prospective study of oral semaglutide in adults with type 2 diabetes in Japanese clinical practice.

MATERIALS AND METHODS

Adults naïve to injectable glucose-lowering therapies initiated oral semaglutide in routine clinical practice and were followed for 34-44 weeks. The primary endpoint was change in glycated hemoglobin (HbA1c) from baseline to end of study; the co-primary endpoint was number of adverse events (AEs). Secondary endpoints included change in bodyweight from baseline to end of study. Analyses were also carried out for subgroups aged <75 and ≥75 years.

RESULTS

A total of 624 participants initiated oral semaglutide; 578 completed the study. Mean baseline HbA1c and bodyweight were 7.7% and 72.4 kg, respectively. At end of study, estimated change (95% confidence interval [CI]) in HbA1c from baseline was -0.7 percentage points (-0.77, -0.61) overall, -0.8 percentage points (-0.86, -0.67) in the <75 years subgroup and -0.5 percentage points (-0.68, -0.41) in the ≥75 years subgroup (all P < 0.0001). Estimated change (95% CI) in bodyweight was -2.8 (-3.19, -2.50) kg overall, -2.9 (-3.38, -2.49) kg in the <75 years subgroup and - 2.7 (-3.18, -2.14) kg in the ≥75 years subgroup (all P < 0.0001). AEs occurred in 161 (25.8%) participants: 99 of 423 (23.4%) and 62 of 201 (30.8%) participants in the <75 and ≥75 years subgroups, respectively. Gastrointestinal AEs were the AEs most frequently leading to oral semaglutide discontinuation.

CONCLUSIONS

In routine clinical practice, HbA1c and bodyweight were significantly reduced from baseline in adults initiating oral semaglutide, including those aged ≥75 years, with no new safety concerns.

Efficacy and safety of switching from a dipeptidyl peptidase-4 inhibitor to oral semaglutide in Japanese patients with type 2 diabetes mellitus

Background

Dipeptidyl peptidase-4 inhibitors (DPP-4is) are the most widely used oral hypoglycemic drugs in Japan. However, once-daily oral semaglutide has been reported to reduce glycated hemoglobin (HbA1c) and body weight (BW) without causing significant hypoglycemia. Here, we aimed to evaluate the efficacy and safety of switching from a DPP-4i to oral semaglutide in Japanese patients with type 2 diabetes (T2D).

Methods

We performed a single-center retrospective study of the changes in HbA1c and BW in 68 patients with T2D who were switched from a DPP-4i and took oral semaglutide for  ≥ 6 months, without changes in any other oral hypoglycemic agent.

Results

Mean HbA1c decreased from 7.8 to 7.0% (p < 0.001) and BW decreased from 74.2 to 71.2 kg (p < 0.001) over 6 months. The decrease in HbA1c was more pronounced in participants with high baseline HbA1c (r =  - 0.542, p < 0.001). There was also a trend (r = 0.236, p = 0.052) toward a decrease in BW in individuals with shorter disease duration. There were reductions in either HbA1c or BW in 65 participants (95.6%). In addition, the larger the decrease in HbA1c was, the greater was the decrease in BW (r = 0.480, p < 0.001). Eighteen participants (20.1%) discontinued the drug within 6 months, of whom 10 (11.6% of the total) did so because of suspected adverse effects and the discontinuation rate was the highest in older, non-obese patients.

Conclusions

Switching from a DPP-4i to oral semaglutide may be useful for Japanese patients with T2D who have inadequate glycemic or BW control. However, its utility may be limited by gastrointestinal adverse effects in certain patients.

Retrospective Study of IDegLira, a New Fixed-Ratio Combination, in Japanese Patients With Type 2 Diabetes Mellitus: Analysis of Background Factors Affecting Effectiveness After 6 Months of Treatment

Background

The aim of the study was to provide real-world data on the effectiveness and safety of a new fixed-ratio combination, insulin degludec/liraglutide (IDegLira) injection in Japanese patients with type 2 diabetes mellitus (T2DM).

Methods

The primary endpoint was the change in glycated hemoglobin (HbA1c) level 6 months after the introduction of IDegLira. We also examined the rate of achievement of target HbA1c 7% and the individualized HbA1c targets set for each patient. Baseline characteristics associated with the change in HbA1c were also assessed. Seventy-five patients with T2DM were included in the analysis.

Results

After the initiation of IDegLira, HbA1c decreased significantly from baseline with a change of -1.81% (baseline 9.61% and at 6 months 7.80%; P < 0.001). At baseline, the achievement rate of 7% HbA1c was 2.67% (n = 2), which increased to 36.0% (n = 27) after 6 months of IDegLira introduction (P < 0.05). The attainment rate of individualized HbA1c targets, which were set considering each patient's characteristics, improved from 2.67% (n = 2) to 49.3% (n = 37) (P < 0.001). Regardless of sex, body mass index, estimated glomerular filtration rate, duration of diabetes, or history of glucagon-like peptide-1 receptor agonist use, IDegLira significantly reduced HbA1c, but a higher C-peptide index was associated with a greater reduction in HbA1c.

Conclusion

In this study, initiation of IDegLira in a real-world clinical setting was beneficial in lowering HbA1c in Japanese T2DM patients with inadequate glycemic control with existing therapy.

Retrospective Analysis of the Effectiveness of Oral Semaglutide in Type 2 Diabetes Mellitus and Its Effect on Cardiometabolic Parameters in Japanese Clinical Settings

Glucagon-like peptide-1 receptor agonists (GLP-1RA) have a more potent glycated hemoglobin (HbA1c)-lowering effect than existing therapies and are widely used for treating type 2 diabetes mellitus (T2DM). Once-daily oral semaglutide is the world's first oral GLP-1RA. This study aimed to provide real-world data on oral semaglutide in Japanese patients with T2DM and its effects on cardiometabolic parameters. This was a single-center retrospective observational study. We examined changes in HbA1c and body weight (BW) and the rate of achieving HbA1c < 7% after 6 months of oral semaglutide treatment in Japanese patients with T2DM. Furthermore, we examined differences in the efficacy of oral semaglutide with multiple patient backgrounds. A total of 88 patients were included in this study. Overall, the mean (standard error of the mean) HbA1c at 6 months decreased by -1.24% (0.20%) from baseline, and BW at 6 months (n = 85) also decreased by -1.44 kg (0.26 kg) from baseline. The percentage of patients who achieved HbA1c < 7% changed significantly from 14% at baseline to 48%. HbA1c decreased from baseline regardless of age, sex, body mass index, chronic kidney disease, or diabetes duration. Additionally, alanine aminotransferase, total cholesterol, triglyceride, and non-high-density lipoprotein cholesterol were significantly reduced from baseline. Oral semaglutide may be an effective option for the intensification of therapy in Japanese patients with T2DM who have inadequate glycemic control with existing therapy. It may also reduce BW and improve cardiometabolic parameters.

A randomized trial to investigate the efficacy and safety of once-daily liraglutide 1.8 mg in Japanese adults with type 2 diabetes exhibiting an inadequate response to liraglutide 0.9 mg

AIMS/INTRODUCTION

The present trial compared the efficacy and safety of once-daily liraglutide 1.8 mg with liraglutide 0.9 mg in Japanese patients with type 2 diabetes to assess the incremental effects of liraglutide 1.8 mg in those who exhibited an inadequate response to 0.9 mg.

MATERIALS AND METHODS

This 26-week randomized trial (NCT02505334) enrolled Japanese adults with type 2 diabetes across 47 sites in Japan. Participants with glycated hemoglobin (HbA1c ) 7.5-10.0% were included and those on insulin treatment were excluded. Participants discontinued pre-trial oral antidiabetic drug and initiated liraglutide 0.9 mg for a 12-week run-in period, after which those with HbA1c ≥7.0% (466) were randomized (1:1) to two treatment arms: continuing liraglutide 0.9 mg or dose escalation to 1.8 mg. The change from baseline in HbA1c (primary endpoint) and treatment-emergent adverse events (secondary endpoint) were measured at the end of 26 weeks.

RESULTS

After 26 weeks of treatment, liraglutide 1.8 mg was more effective compared with 0.9 mg in lowering HbA1c levels, with an estimated treatment difference of -0.40% (95% confidence interval [CI] -0.55, -0.24; P < 0.0001). Liraglutide 1.8 mg was associated with significantly greater odds of participants reaching HbA1c <7.0% (estimated odds ratio [EOR] 3.87; 95% CI 2.12, 7.08; P < 0.0001) and ≤6.5% (EOR 3.78; 95% CI 1.36, 10.54; P = 0.0109) compared with 0.9 mg. Both doses were well tolerated.

CONCLUSIONS

Liraglutide 1.8 mg had better efficacy in improving HbA1c levels after 26 weeks treatment vs 0.9 mg in Japanese patients, with both doses well tolerated.

Efficacy of IDegLira Versus IDegAsp Therapy in Patients with Type 2 Diabetes: A Randomized Crossover Study by isCGM

Introduction

We aimed to compare the efficacy of insulin degludec/insulin aspart (IDegAsp) and insulin degludec/liraglutide (IDegLira) in controlling glucose fluctuation and suppressing postprandial glucose levels using intermittently scanned continuous glucose monitoring.

Methods

Twenty-four patients with type 2 diabetes mellitus were randomly allocated to receive either IDegLira or IDegAsp followed by IDegAsp or IDegLira, respectively. A crossover study was conducted with intermittently scanned continuous glucose monitoring. We compared the postprandial blood glucose level, time in range, and time below range from a 3-day intermittently scanned continuous glucose monitoring period for each treatment group.

Results

The time in range was significantly higher in IDegLira than in IDegAsp. Postprandial glucose levels 90 and 120 min after breakfast and 60, 90, and 120 min after lunch were significantly lower for IDegLira than for IDegAsp. However, postprandial glucose levels 90 and 120 min after supper were significantly lower for IDegAsp than for IDegLira. There was no significant difference in the time below range between IDegLira and IDegAsp.

Conclusion

IDegLira was more effective in treating type 2 diabetes mellitus than IDegAsp, as indicated by a higher time in range and lower postprandial glucose level at breakfast and lunch. This study was registered with the University Hospital Medical Information Network Clinical Trial Registry (UMIN 000039221).

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02138-w.

The Amount of Residual Incretin Regulates the Pancreatic β-cell Function and Glucose Homeostasis

The gastrointestinal tract is considered an important endocrine organ for controlling glucose homeostasis via the production of incretins. A 21-year-old man emergently underwent total colectomy due to severe ulcerative colitis, and overt diabetes became evident. Weekly administration of a glucagon-like peptide (GLP)-1 receptor agonist (RA) dramatically improved his glucose control. Levels of GLP-1 or gastric inhibitory polypeptide (GIP) were low at the baseline in the duodenum and serum of the patient. After 11 months of GLP-1RA treatment, his HbA1c worsened again, and intensive insulin therapy was necessary to control his glucose levels. Our report may explain the significance of residual incretin for maintaining the pancreatic β-cell function.

Association of glucagon-like peptide-1 receptor-targeted imaging probe with in vivo glucagon-like peptide-1 receptor agonist glucose-lowering effects

Aims/Introduction

Glucagon‐like peptide‐1 receptor agonists (GLP‐1RA) are used for treatment of type 2 diabetes mellitus worldwide. However, some patients do not respond well to the therapy, and caution must be taken for certain patients, including those with reduced insulin secretory capacity. Thus, it is clinically important to predict the efficacy of GLP‐1RA therapy. GLP‐1R‐targeted imaging has recently emerged to visualize and quantify β‐cells. We investigated whether GLP‐1R‐targeted imaging can predict the efficacy of GLP‐1RA treatment.

Materials and Methods

We developed ¹¹¹Indium‐labeled exendin‐4 derivative (¹¹¹In‐Ex4) as a GLP‐1R‐targeting probe. Diabetic mice were selected from NONcNZO10/LtJ male mice that were fed for different durations with 11% fat chow. After 3‐week administration of dulaglutide as GLP‐1RA therapy, mice with non‐fasting blood glucose levels <300 mg/dL and >300 mg/dL were defined as responders and non‐responders, respectively. In addition, ex vivo¹¹¹In‐Ex4 pancreatic accumulations (¹¹¹In‐Ex4 pancreatic values) were examined.

Results

The non‐fasting blood glucose levels after treatment were 172.5 ± 42.4 mg/dL in responders (n = 4) and 330.8 ± 20.7 mg/dL in non‐responders (n = 5), respectively. Ex vivo¹¹¹In‐Ex4 pancreatic values showed significant correlations with post‐treatment glycohemoglobin and glucose area under curve during an oral glucose tolerance test (R² = 0.76 and 0.80; P < 0.01 and <0.01, respectively). The receiver operating characteristic area under curve for identifying responders by ex vivo¹¹¹In‐Ex4 pancreatic values was 1.00 (P < 0.01).

Conclusion

Ex vivo¹¹¹In‐Ex4 pancreatic values reflected dulaglutide efficacy, suggesting clinical possibilities for expanding GLP‐1R‐targeted imaging applications.

Magnitude of slowing gastric emptying by glucagon-like peptide-1 receptor agonists determines the amelioration of postprandial glucose excursion in Japanese patients with type 2 diabetes

AIMS/INTRODUCTION

Pharmacological levels of glucagon-like peptide-1 (GLP-1) can decelerate gastric emptying (GE) and reduce postprandial glucose levels. Most previous studies have used liquid meals to evaluate GE. We evaluated the effects of GLP-1 receptor agonists (GLP-1 RAs) on GE and postprandial glucose excursion in Japanese type 2 diabetes mellitus patients using a combination of solid and liquid meals.

MATERIALS AND METHODS

In this single-center, prospective, open-label study, nine healthy individuals and 17 patients with type 2 diabetes mellitus consumed a 460-kcal combination of a solid and liquid meal labeled with 13 C-acetic acid. GE was measured from t = 0 to 150 min in a continuous 13 C breath test. Eight participants with type 2 diabetes mellitus were administered GLP-1 RAs, and we examined the relationship between GE and blood glucose excursion.

RESULTS

There were no differences in the average GE coefficient (GEC) and lag time between the healthy and type 2 diabetes mellitus groups. However, the type 2 diabetes mellitus group showed larger GEC variations (P < 0.05). The coefficient of variation of R-R intervals was a significant predictor of GEC in type 2 diabetes mellitus patients (P < 0.01). The short-acting GLP-1 RA reduced the GEC at 1 month (P = 0.012), whereas the long-acting GLP-1 RA did not significantly change the GEC after treatment. A positive relationship was observed between postprandial glucose excursion from T0 min to T60 min and the GEC (r2  = 0.75; P < 0.01).

CONCLUSIONS

The reduction in GE rate by the administration of GLP-1 RAs can predict the improvement in postprandial glucose excursion in type 2 diabetes mellitus patients.

Glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes:real-world evidence from a Mediterranean area

Aims: To assess clinical characteristics and factors associated with glycated hemoglobin (HbA1c) reduction in type 2 diabetes (T2DM) patients initiating glucagon-like peptide-1 receptor agonists (GLP-1RAs). Methods: Retrospective cohort study in patients with T2DM who initiated GLP-1RAs between 2007 and 2014 in primary health care centers in Catalonia (Spain). We evaluated changes in HbA1c and body weight at 6-12 months, and factors independently associated with achieving ≥1% HbA1c target reduction. Results: Overall, 4242 patients (47.9% male; mean BMI 37.5 kg/m²) initiated a GLP-1RA. At 6-12 months, the mean HbA1c level decreased from the baseline 8.8% to 7.7% (-1.0%; SD = 1.6). A 1% reduction in HbA1c was observed in 47.2% of patients. Patients lost a mean of 3.6 kg (SD = 6.2). Sixty percent of patients reduced both HbA1c and body weight, and 17% achieved only one of these targets. Independent determinants of a 1% HbA1c reduction were baseline HbA1c, age, diabetes duration and being on insulin treatment. Reduction in weight or HbA1c and the proportion of patients achieving a HbA1c reduction of ≥1% was significantly larger among subjects prescribed liraglutide than exenatide and lixisenatide. Conclusions: In this real-world, retrospective study, the magnitude of HbA1c and body weight reductions after addition of a GLP-1RA were similar to those observed in randomized controlled trials. Approximately 60% of patients attained reductions in both HbA1c and body weight, and there were significant differences among different drugs from this therapeutic group.

C-Peptide Area Under the Curve at Glucagon Stimulation Test Predicts Glucose Improvements by GLP-1 Receptor Analogue: A Retrospective Observational Study

INTRODUCTION

Despite the widespread use of glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1ras) to improve glycemic regulation, with a low risk of hypoglycemia and weight reduction, their effectiveness varies among individuals. This study aimed to identify predictors of the efficacy of GLP-1ra on Hemoglobin A1c (HbA1c) in patients with insulin-independent diabetes.

METHODS

In total, 58 patients with insulin-independent diabetes were included. Patients were included if their β-cell function was evaluated via a glucagon stimulation test (GST) before the introduction of GLP-1ra therapy. β-Cell function-related indices, such as the C-peptide index (CPI), increments in C-peptide immunoreactivity (CPR) after glucagon stimulation (ΔCPR), and the area under the CPR curve (CPR-AUC) during the GST, were evaluated. HbA1c and body weight (BW) were measured at 6 and 12 months after the initiation of GLP-1ra.

RESULTS

A univariate regression analysis revealed a significant correlation between CPR-AUC and changes in HbA1c at 6 months and with changes in BW at 6 and 12 months. A multivariate regression analysis revealed that CPR-AUC was significantly correlated with changes in HbA1c at 6 months. A receiver-operating characteristic analysis revealed that 21.9 ng/ml·min CPR-AUC was the optimal cut-off value to predict an HbA1c level < 7%, i.e., 53 mmol/mol.

CONCLUSION

Residual β-cell function, as assessed via CPR-AUC in the GST, is an effective predictor of the efficacy of GLP-1ras.

Retrospective analysis of liraglutide and basal insulin combination therapy in Japanese type 2 diabetes patients: The association between remaining β-cell function and the achievement of the glycated hemoglobin target 1 year after initiation

AIMS/INTRODUCTION

The glucose-lowering effects of the glucagon-like peptide-1 receptor agonist, liraglutide, have been shown to rely on remaining β-cell function. However, the possible associations of remaining β-cell function with the glucose-lowering effects of liraglutide in combination with basal insulin remain unknown and warrant investigation.

MATERIALS AND METHODS

This was a single-center, retrospective, observational study carried out in a private hospital in Osaka, Japan. Type 2 diabetes patients who received a prescription change from insulin therapy, both multiple-dose insulin and basal insulin-supported oral therapy, to liraglutide and basal insulin combination and continued the therapy for 54 weeks without additional oral antidiabetic drugs or bolus insulin were retrospectively analyzed.

RESULTS

Among the 72 participants who received a prescription change from multiple-dose insulin and basal insulin-supported oral therapy to liraglutide and basal insulin combination, 57 continued the therapy for 54 weeks. Of those who continued the therapy without receiving additional oral antidiabetic drugs or bolus insulin, seven participants achieved glycated hemoglobin < 7.0% at 54 weeks, but 30 participants did not. The participants who achieved glycated hemoglobin < 7.0% at 54 weeks had a significantly higher C-peptide immunoreactivity index, a β-cell function-related index frequently used in Japanese clinical settings. The receiver operating curve analysis showed that the C-peptide immunoreactivity index cut-off value for the achievement of glycated hemoglobin <7.0% at 54 weeks is 1.103.

CONCLUSIONS

The current findings show that the glucose-lowering effects of liraglutide rely on remaining β-cell function, even when used with basal insulin; and suggest that liraglutide and basal insulin combination might require additional bolus insulin to fully compensate insulin insufficiency in individuals with reduced β-cell function.

Reply to the comment of Wilbrink et al. on Retrospective analysis of liraglutide and basal insulin combination therapy in Japanese type 2 diabetes: The association between remaining β-cell function and the achievement of the HbA1c target 1 year after initiation

We have reported that the HbA1c-lowering effects of liraglutide/basal insulin combination rely on remaining β-cell function and that the cut-off value of the C-peptide immunoreactivity index (CPI), a β-cell function-related index frequently used in Japanese clinical settings, is 1.103 for the achievement of HbA1c <7.0% at 54 weeks after initiating the liraglutide/basal insulin combination. Wilbrink et al claimed that glucose-lowering effects of glucagon-like peptide-1 receptor agonist liraglutide depend of duration of type 2 diabetes; while our resent study published in the Journal of Diabetes Investigation failed to detect such dependency. This discrepancy might be due to several reasons including co-administration of basal insulin with liraglutide in our study; ethnic difference in T2D pathophysiology between the two study; and difference in sample size (The Usui study on liraglutide/basal insulin, n = 38; the Usui study on liraglutide monotherapy or SU combination, n=88; and the Wilbrink study, n = 69).

Reduction of visceral fat by liraglutide is associated with ameliorations of hepatic steatosis, albuminuria, and micro-inflammation in type 2 diabetic patients with insulin treatment: a randomized control trial

Liraglutide, an analogue of human glucagon-like peptide 1, reduces cardiovascular events in patients with type 2 diabetes; however, it has still been unknown by which mechanisms liraglutide could reduce cardiovascular events. Type 2 diabetic patients with insulin treatment were enrolled in this randomized, open-label, comparative study. Participants were randomly assigned to liraglutide plus insulin (liraglutide group) and insulin treatment (control group) at 1:1 allocation. Primary endpoint was the change in viscera fat are (VFA, cm²) at 24 weeks. Liver attenuation index (LAI) measured by abdominal computed tomography, urinary albumin-to-creatinine ratio (ACR, mg/g), and C-reactive protein (CRP) levels, skeletal muscle index (SMI), and quality of life (QOL) related to diabetes treatment were also determined. Seventeen patients (8; liraglutide group, 9; control group, mean age 59 ± 13 years; 53% female) completed this study. Liraglutide treatment significantly reduced VFA at 24 weeks; whereas, SFA was unchanged. ACR, LAI, and CRP levels were significantly reduced by liraglutide at 24 weeks and there was no difference in SMI between the two groups. Changes in VFA from baseline to 24 weeks were significantly associated with those in LAI, albuminuria, and HbA1c. Liraglutide treatment significantly improved QOL scores associated with anxiety and dissatisfaction with treatment and satisfaction with treatment. No severe adverse events were observed in both groups. Our data suggest that liraglutide could reduce visceral adiposity in parallel with attenuation of hepatic fat accumulation, albuminuria and micro-inflammation and improve QOL related to diabetes care in insulin-treated patients with type 2 diabetes.

Evaluation of large-scale clinical trials on cardiovascular disease risk in patients with type 2 diabetes mellitus treated with dipeptidyl peptidase 4 inhibitors and a new class of drugs

Several recent prospective cardiovascular clinical trials completed with newly developed drugs for the treatment of type 2 diabetes mellitus have been published. Caution must be used when interpreting these studies.

Is there a justification for classifying GLP-1 receptor agonists as basal and prandial?

Several GLP-1 receptor agonists are currently available for treatment of type 2 diabetic patients. Based on their pharmacokinetic/pharmacodynamic profile, these drugs are classified as short-acting GLP-1 receptor agonists (exenatide and lixisenatide) or long-acting GLP-1 receptor agonists (exenatide-LAR, liraglutide, albiglutide, and dulaglutide). In clinical practice, they are also classified as basal or prandial GLP-1 receptor agonists to differentiate between patients who would benefit more from one or another based on characteristics such as previous treatment and the predominance of fasting or postprandial hyperglycemia. In the present article we examine available data on the pharmacokinetic characteristics of the various GLP-1 agonists and compare their effects with respect to the main parameters used to evaluate glycemic control. The article also analyzes whether the differences between the different GLP-1 agonists justify their classification as basal or prandial.

Anagliptin increases insulin-induced skeletal muscle glucose uptake via an NO-dependent mechanism in mice

AIMS/HYPOTHESIS

Recently, incretin-related agents have been reported to attenuate insulin resistance in animal models, although the underlying mechanisms remain unclear. In this study, we investigated whether anagliptin, the dipeptidyl peptidase 4 (DPP-4) inhibitor, attenuates skeletal muscle insulin resistance through endothelial nitric oxide synthase (eNOS) activation in the endothelial cells. We used endothelium-specific Irs2-knockout (ETIrs2KO) mice, which show skeletal muscle insulin resistance resulting from a reduction of insulin-induced skeletal muscle capillary recruitment as a consequence of impaired eNOS activation.

METHODS

In vivo, 8-week-old male ETIrs2KO mice were fed regular chow with or without 0.3% (wt/wt) DPP-4 inhibitor for 8 weeks to assess capillary recruitment and glucose uptake by the skeletal muscle. In vitro, human coronary arterial endothelial cells (HCAECs) were used to explore the effect of glucagon-like peptide 1 (GLP-1) on eNOS activity.

RESULTS

Treatment with anagliptin ameliorated the impaired insulin-induced increase in capillary blood volume, interstitial insulin concentration and skeletal muscle glucose uptake in ETIrs2KO mice. This improvement in insulin-induced glucose uptake was almost completely abrogated by the GLP-1 receptor (GLP-1R) antagonist exendin-(9-39). Moreover, the increase in capillary blood volume with anagliptin treatment was also completely inhibited by the NOS inhibitor. GLP-1 augmented eNOS phosphorylation in HCAECs, with the effect completely disappearing after exposure to the protein kinase A (PKA) inhibitor H89. These data suggest that anagliptin treatment enhances insulin-induced capillary recruitment and interstitial insulin concentrations, resulting in improved skeletal muscle glucose uptake by directly acting on the endothelial cells via NO- and GLP-1-dependent mechanisms in vivo.

CONCLUSIONS/INTERPRETATION

Anagliptin may be a promising agent to ameliorate skeletal muscle insulin resistance in obese patients with type 2 diabetes.

C-Peptide Level in Fasting Plasma and Pooled Urine Predicts HbA1c after Hospitalization in Patients with Type 2 Diabetes Mellitus

In this study, we investigate how measures of insulin secretion and other clinical information affect long-term glycemic control in patients with type 2 diabetes mellitus. Between October 2012 and June 2014, we monitored 202 diabetes patients who were admitted to the hospital of Asahi Life Foundation for glycemic control, as well as for training and education in diabetes management. We measured glycated hemoglobin (HbA1c) six months after discharge to assess disease management. In univariate analysis, fasting plasma C-peptide immunoreactivity (F-CPR) and pooled urine CPR (U-CPR) were significantly associated with HbA1c, in contrast to ΔCPR and C-peptide index (CPI). This association was strongly independent of most other patient variables. In exploratory factor analysis, five underlying factors, namely insulin resistance, aging, sex differences, insulin secretion, and glycemic control, represented patient characteristics. In particular, insulin secretion and resistance strongly influenced F-CPR, while insulin secretion affected U-CPR. In conclusion, the data indicate that among patients with type 2 diabetes mellitus, F-CPR and U-CPR may predict improved glycemic control six months after hospitalization.