Insulin secretion and insulin sensitivity at different stages of glucose tolerance: a cross-sectional study of Japanese type 2 diabetes

Young-onset type 2 diabetes-Epidemiology, pathophysiology, and management

The prevalence and incidence of young-onset type 2 diabetes is increasing globally, especially in low- and middle-income countries, and predominantly affects non-White ethnic and racial populations. Young-onset type 2 is heterogeneous in terms of the genetic and environmental contributions to its underlying pathophysiology, which poses challenges for glycemic management. Young at-risk individuals remain underrepresented in clinical trials, including diabetes prevention studies, and there is still an insufficient evidence base to inform practice for this age group. Improvements in diabetes care delivery have not reached young people who will progress to have disabling complications at an age when they are most productive. This review summarizes recent studies on the epidemiology of young-onset type 2 diabetes and its complications. We discuss the genetic and environmental risk factors that act in concert to promote glycemic dysregulation and early onset of type 2 diabetes. We provide perspectives on diabetes prevention and management, and propose strategies to address the unique medical and psychosocial issues associated with young-onset type 2 diabetes. The Precision Medicine to Redefine Insulin Secretion and Monogenic Diabetes Randomized Controlled Trial (PRISM-RCT) is the first large-scale clinical trial designed to evaluate the effect of a structured care model that integrates biogenetic markers with communication and information technology on attaining strict metabolic targets and improving clinical outcomes in individuals with young-onset type 2 diabetes. The results of this study will inform the scientific community about the impact of multifactorial intervention and precision care in young patients, for whom the legacy effect is particularly significant.

Pathogenesis of type 2 diabetes in Japan and East Asian populations: Basic and clinical explorations

It is now accepted that the pathogenesis of type 2 diabetes in East Asians including Japanese differs distinctly from that in Caucasians. Many non-obese individuals in Japan develop type 2 diabetes and present clinically with insufficient insulin secretion rather than a large increase in the insulin resistance. To understand the pathophysiology of this non-obese diabetes, we studied Goto-Kakizaki rats, a unique model of spontaneous non-obese diabetes, and identified mitochondrial dysfunction in pancreatic β-cells as a factor in decreased insulin secretion. Looking for a clinical treatment option, we focused on the incretins because of their glucose-dependent insulin stimulatory effect. Our findings have contributed to the understanding of incretin action and the development of incretin-associated therapeutics and shed light on the nature of East Asian diabetes and its optimal clinical treatment.

Efficacy and safety of once-weekly insulin icodec versus once-daily basal insulin in Japanese individuals with type 2 diabetes: A subgroup analysis of the ONWARDS 1, 2 and 4 trials

AIM

To explore the efficacy and safety of once-weekly insulin icodec (icodec) in Japanese adults (≥20 years old) with type 2 diabetes from the global ONWARDS 1, 2 and 4 trials.

MATERIALS AND METHODS

Insulin-naive (ONWARDS 1) and insulin-experienced (ONWARDS 2 and 4) individuals were randomized to icodec or a once-daily insulin comparator: insulin glargine U100 [ONWARDS 1 (basal insulin only) and 4 (basal-bolus regimen)] or insulin degludec [ONWARDS 2 (basal insulin only)]. The primary outcome was change in glycated haemoglobin from baseline to end of treatment (EOT) (ONWARDS 1: Week 52; ONWARDS 2 and 4: Week 26). Here, we present the Japanese subgroup results.

RESULTS

Similar reductions in glycated haemoglobin from baseline to EOT were observed in each trial for icodec and comparators. The proportion of time in range (blood glucose 3.9-10.0 mmol/L) at EOT was also comparable across treatment groups (time in range: 58%-68%), as was time spent with blood glucose below 3.0 mmol/L (<1.0%). Combined clinically significant (blood glucose <3.0 mmol/L) or severe (requiring external assistance for recovery) hypoglycaemia rates were low, with no severe events (ONWARDS 1 and 2) or a single severe event (ONWARDS 4; icodec group) reported. These results generally aligned with findings from the respective global populations. No new safety issues were identified.

CONCLUSIONS

Icodec improved glycaemic control to a similar degree as once-daily basal insulin comparators while maintaining low levels of clinically significant or severe hypoglycaemia. The findings support icodec use in Japanese individuals with different levels of type 2 diabetes progression.

Rationale and Design of the Study to Investigate the Metabolic Action of Imeglimin on Patients with Type 2 Diabetes Mellitus (SISIMAI)

INTRODUCTION

Imeglimin is a first-in-class, novel, oral glucose-lowering agent for the treatment of type 2 diabetes mellitus. The efficacy and safety of imeglimin as an antidiabetic agent have been investigated in clinical trials. However, its metabolic effects in humans have not yet been fully elucidated.

METHODS

The Study to InveStIgate the Metabolic Action of Imeglimin on patients with type 2 diabetes mellitus (SISIMAI) is a single-arm intervention study. In this study, we have recruited 25 patients with type 2 diabetes to receive 2000 mg/day imeglimin for 20 weeks. We perform a 75-g oral glucose tolerance test (OGTT) with double-glucose tracers, a two-step hyperinsulinemic-euglycemic clamp with glucose tracer, ectopic fat measurement by proton magnetic resonance spectroscopy, visceral/subcutaneous fat area measurement by magnetic resonance imaging, muscle biopsy, and evaluation of fitness level by cycle ergometer before and after imeglimin administration.

PLANNED OUTCOMES

The primary outcome is the change in area under the curve of glucose levels during the OGTT after 20 weeks of imeglimin treatment. We also calculate the endogenous glucose production, rate of oral glucose appearance, and rate of glucose disappearance from the data during the 75-g OGTT and compare them between pre- and post-treatment. Additionally, we will compare other parameters, such as the changes in tissue-specific insulin sensitivity, ectopic fat accumulation, visceral/subcutaneous fat area accumulation, and fitness level between each point. This is the first study to investigate the organ-specific metabolic action of imeglimin in patients with type 2 diabetes mellitus using the 75-g OGTT with the double tracer method. The results of this study are expected to provide useful information for drug selection based on the pathophysiology of individual patients with type 2 diabetes mellitus.

TRIAL REGISTRATION

jRCTs031210600.

High prevalence of copy number variations in the Japanese participants with suspected MODY

Maturity-Onset Diabetes of the Young (MODY) is a diabetes mellitus subtype caused by a single gene. The detection rate of the responsible gene is 27% in the United Kingdom, indicating that the causative gene remains unknown in the majority of clinically diagnosed MODY cases. To improve the detection rate, we applied comprehensive genetic testing using whole exome sequencing (WES) followed by Multiplex Ligation-dependent Probe Amplification (MLPA) and functional analyses. Twenty-one unrelated Japanese participants with MODY were enrolled in the study. To detect copy number variations (CNVs), WES was performed first, followed by MLPA analysis for participants who were negative on the basis of WES. Undetermined variants were analyzed according to their functional properties. WES identified 7 pathogenic and 3 novel likely pathogenic variants in the 21 participants. Functional analyses revealed that 1 in 3 variants was pathogenic. MLPA analysis applied to the remaining 13 undetermined samples identified 4 cases with pathogenic CNVs: 3 in HNF4A and 1 in HNF1B. Pathogenic variants were identified in 12 participants (12/21, 57.1%) - relatively high rate reported to date. Notably, one-third of the participants had CNVs in HNF4A or HNF1B, indicating a limitation of WES-only screening.

A consensus statement from the Japan Diabetes Society: A proposed algorithm for pharmacotherapy in people with type 2 diabetes - 2nd edition (English version)

This algorithm was issued for the appropriate use of drugs for the treatment of type 2 diabetes mellitus in Japan. The revisions include safety considerations, fatty liver disease as a comorbidity to be taken into account and the position of tirzepatide.

Pathological evaluation of the pathogenesis of diabetes mellitus and diabetic peripheral neuropathy

Currently, there are more than 10 million patients with diabetes mellitus in Japan. Therefore, the need to explore the pathogenesis of diabetes and the complications leading to its cure is becoming increasingly urgent. Pathological examination of pancreatic tissues from patients with type 2 diabetes reveals a decrease in the volume of beta cells because of a combination of various stresses. In human type 2 diabetes, islet amyloid deposition is a unique pathological change characterized by proinflammatory macrophage (M1) infiltration into the islets. The pathological changes in the pancreas with islet amyloid were different according to clinical factors, which suggests that type 2 diabetes can be further subclassified based on islet pathology. On the other hand, diabetic peripheral neuropathy is the most frequent diabetic complication. In early diabetic peripheral neuropathy, M1 infiltration in the sciatic nerve evokes oxidative stress or attenuates retrograde axonal transport, as clearly demonstrated by in vitro live imaging. Furthermore, islet parasympathetic nerve density and beta cell volume were inversely correlated in type 2 diabetic Goto-Kakizaki rats, suggesting that diabetic peripheral neuropathy itself may contribute to the decrease in beta cell volume. These findings suggest that the pathogenesis of diabetes mellitus and diabetic peripheral neuropathy may be interrelated.

Impact of Initial Treatment Policies on Long-term Complications and Costs in Japanese Patients with Type 2 Diabetes: A Real-World Database Study

INTRODUCTION

Type 2 diabetes (T2D) represents a remarkable disease burden in Japan, and the cost-effectiveness of pharmacotherapy is an important consideration. In this study, we compared the long-term effects of the type of initial medication, as well as the initial frequency of clinic visits, on the occurrence of T2D-related complications. Additionally, we compared the medical costs associated with each treatment pattern.

METHODS

We analyzed electronic health record data collected from multiple primary care clinics in Japan. Patients were selected based on being primarily prescribed either biguanides (BG) or DPP-4 inhibitors (DPP-4i) during a 3-month baseline period, both of which are commonly used as first-choice medications in Japan. We then followed the onset of T2D-related complications and conducted survival analyses. Additionally, we calculated the accumulated medical costs up to the onset of an event or loss to follow-up, and summarized the annual costs per patient for each treatment pattern.

RESULTS

A total of 416 Japanese patients with T2D who initiated treatment between January 2015 and September 2021 were included. The median follow-up period was 2.69 years. The survival analysis showed that the use of DPP-4is and frequent visits from the beginning of treatment did not offer a benefit in suppressing the onset of complications later on. On the other hand, it was found that the annual medical costs for the group using DPP-4i with frequent visits were about 1.9 times higher than for the group using BGs with less frequent visits.

CONCLUSIONS

The results suggest that for Japanese patients with T2D, the use of BGs along with relatively long follow-up intervals in the beginning of treatment can remarkably reduce medical costs while providing a level of complication suppression equivalent to that of the use of DPP-4is or frequent visits.

A consensus statement from the Japan Diabetes Society (JDS): a proposed algorithm for pharmacotherapy in people with type 2 diabetes-2nd Edition (English version)

The Japan Diabetes Society (JDS) adopted a sweeping decision to release consensus statements on relevant issues in diabetes management that require updating from time to time and launched a "JDS Committee on Consensus Statement Development." In March 2020, the committee's first consensus statement on "Medical Nutrition Therapy and Dietary Counseling for People with Diabetes" was published. In September 2022, a second consensus "algorithm for pharmacotherapy in people with type 2 diabetes" was proposed. In developing an algorithm for diabetes pharmacotherapy in people with type 2 diabetes, the working concept was that priority should be given to selecting such medications as would appropriately address the diabetes pathology in each patient while simultaneously weighing the available evidence for these medications and the prescribing patterns in clinical practice in Japan. These consensus statements are intended to present the committee's take on diabetes management in Japan, based on the evidence currently available for each of the issues addressed. It is thus hoped that practicing diabetologists will not fail to consult these statements to provide the best available practice in their respective clinical settings. Given that the persistent dual GIP/GLP-1 receptor agonist tirzepatide was approved in April 2023, these consensus statements have been revised1). In this revision, specifically, tirzepatide was added to the end of [likely involving insulin resistance] of "Obese patients" in Step 1: "Select medications to address the diabetes pathology involved" in Fig. 2. While the sentence, "Insulin insufficiency and resistance can be assessed by referring to the various indices listed in the JDS 'Guide to Diabetes Management.' was mentioned in the previous edition as well, "While insulin resistance is analogized based on BMI, abdominal obesity, and visceral fat accumulation, an assessment of indicators (e.g., HOMA-IR) is desirable" was added as information in order to more accurately recognize the pathology. Regarding Step 2: "Give due consideration to safety," "For renal excretion" was added to the "Rule of thumb 2: Avoid glinides in patients with renal impairment." The order of the medications in "rule of thumb 3: Avoid thiazolidinediones and biguanides in patients with heart failure (in whom they are contraindicated)." to thiazolidinediones then biguanides. In the description of the lowest part of Fig. 2, for each patient failing to achieve his/her HbA1c control goal, "while reverting to step 1" was changed to "while reverting to the opening" and "including reassessment if the patient is indicated for insulin therapy" was added. In the separate table, the column for tirzepatides was added, while the two items, "Characteristic side effects" and "Persistence of effect" were added to the area of interest. The revision also carried additional descriptions of the figure and table such as tirzepatides and "Characteristic side effects" in the statement, and while not mentioned in the proposed algorithm figure, nonalcoholic fatty liver disease (NAFLD) is covered from this revision for patients with comorbidities calling for medical attention. Moreover, detailed information was added to the relative/absolute indication for insulin therapy, the Kumamoto Declaration 2013 for glycemic targets, and glycemic targets for older people with diabetes. Again, in this revision, it is hoped that the algorithm presented here will not only contribute to improved diabetes management in Japan, but will continue to evolve into a better algorithm over time, reflecting new evidence as it becomes available.

Effects of Once-Weekly Semaglutide on Cardiovascular Risk Factors and Metabolic Dysfunction-Associated Steatotic Liver Disease in Japanese Patients with Type 2 Diabetes: A Retrospective Longitudinal Study Based on Real-World Data

Once-weekly semaglutide is a widely used glucagon-like peptide-1 receptor agonist (GLP-1RA) used for the treatment of type 2 diabetes (T2D). In clinical trials, semaglutide improved glycemic control and obesity, and reduced major cardiovascular events. However, the reports are limited on its real-world efficacy relating to various metabolic factors such as dyslipidemia or metabolic dysfunction-associated steatotic liver disease (MASLD) in Asian patients with T2D. In our retrospective longitudinal study, we selected patients with T2D who were given once-weekly semaglutide and compared metabolic parameters before and after the start of semaglutide. Seventy-five patients were eligible. HbA1c decreased significantly, by 0.7-0.9%, and body weight by 1.4-1.7 kg during the semaglutide treatment. Non-HDL cholesterol decreased significantly at 3, 6 and 12 months after the initiation of semaglutide; LDL cholesterol decreased at 3 and 6 months; and HDL cholesterol increased at 12 months. The effects on body weight, HbA1c and lipid profile were pronounced in patients who were given semaglutide as a first GLP-1RA (GLP-1R naïve), whereas improvements in HbA1c were also observed in patients who were given semaglutide after being switched from other GLP-1RAs. During a 12-month semaglutide treatment, the hepatic steatosis index (HSI) tended to decrease. Moreover, a significant decrease in the AST-to-platelet ratio index (APRI) was observed in GLP-1RA naïve patients. Our real-world study confirmed the beneficial effects of once-weekly semaglutide, namely, improved body weight, glycemic control and atherogenic lipid profile. The beneficial effects on MASLD were also suggested.

Usefulness of Once-Weekly GLP-1 Receptor Agonist Semaglutide on Glycemic Control in Subjects with Type 2 Diabetes Mellitus: Switching from the Same Class Dulaglutide in a Retrospective Observation Study

Recently, the development of once-weekly incretin-based injections dulaglutide and semaglutide has drawn a great deal of attention. This study is aimed at comparing the efficacy of once-weekly GLP-1 receptor activator (GLP-1RA) dulaglutide and semaglutide on glycemic control and several metabolic parameters in patients with type 2 diabetes mellitus. We compared various clinical parameters between before and after switching from dulaglutide to semaglutide in "study 1" (pre-post comparison) and set the control group using propensity score matching method in "study 2." In "study 1," six months after the switching, HbA1c was significantly reduced from 8.2% to 7.6% and body mass index was also decreased from 30.4 kg/m2 to 30.0 kg/m2. Such effects were more pronounced in subjects whose glycemic control was poor. In "study 2," after 1 : 1 propensity score matching, glycemic control and body weight management were improved in the switching group compared with the dulaglutide continuation group. In this study including obese subjects with poor glycemic control, switching dulaglutide to semaglutide showed more beneficial effects on both glycemic and weight control irrespective of age, body weight, and diabetes duration. Therefore, we should bear in mind that it would be better to start using a relatively new once-weekly GLP-1RA semaglutide in clinical practice, especially in obese subjects with poor glycemic control with other GLP-1RAs.

The spontaneous-diabetes rat: a model of noninsulin dependent diabetes mellitus by Yoshio Goto and Masaei Kakizaki (1981)

Y. Goto and M. Kakizaki produced a rat model of non-insulin dependent diabetes mellitus (NIDDM) by repetitive selective breeding of rats with slightly impaired glucose tolerance. In contrast to most obese diabetes models, which were genetically modified animals created by inducing a gene mutation, this rat was a unique model because it was a spontaneous diabetes model created by selective breeding. Furthermore, when it became clear that this rat was a non-obese diabetic model that exhibited hyperglycemia due to a decrease in insulin secretion capacity, it was recognized as a valuable model for elucidating non-obese, hypoinsulinemic diabetes commonly seen in East Asians. Diabetes is becoming an important health problem worldwide, especially in the East Asian region, thus Goto-Kakizaki (GK) rats are becoming increasingly important as a model of non-insulin dependent diabetes mellitus.

Comparison of clinical efficacy and safety of weekly glucagon-like peptide-1 receptor agonists dulaglutide and semaglutide in Japanese patients with type 2 diabetes: Randomized, parallel-group, multicentre, open-label trial (COMING study)

AIM

To compare the clinical usefulness of once-weekly glucagon-like peptide-1 receptor agonists dulaglutide and semaglutide at the doses approved for use in Japanese patients with type 2 diabetes.

METHODS

In total, 120 patients with glycated haemoglobin (HbA1c) ≥7% were randomly assigned to dulaglutide (n = 59) or semaglutide group (n = 61), and 107 participants (dulaglutide/semaglutide = 53/54) completed the 24-week trial. The primary endpoint was the difference of HbA1c level between the two groups at 24 weeks.

RESULTS

HbA1c level at 24 weeks was significantly lower in the semaglutide group (7.9 ± 0.5%-6.7 ± 0.5%) compared with the dulaglutide group (8.1 ± 0.6%-7.4 ± 0.8%) (p < .0001). Reduction in body mass index and visceral fat area were also more significant in the semaglutide group (p < .05, respectively). The achievement rate of HbA1c <7% was higher in the semaglutide group (p < .0001). The parameters such as low-density lipoprotein cholesterol, alanine aminotransferase and γ-glutamyl transpeptidase were decreased in the semaglutide group. Surprisingly, only semaglutide group significantly improved the apolipoprotein B/A1 ratio, which is considered a useful myocardial infarction risk index. Using computed tomography, the liver to spleen ratio was significantly elevated only in the semaglutide group. In contrast, gastrointestinal symptoms were observed in 13.2% of dulaglutide and 46.3% of semaglutide group (p < .01). The Diabetes Treatment-Related Quality of Life scores related to pain and gastrointestinal symptoms were also superior in the dulaglutide group.

CONCLUSIONS

This prospective trial showed that semaglutide has more pronounced glucose- and body mass index-lowering effects and reduces liver fat percentage and visceral fat area and that dulaglutide has less gastrointestinal symptoms and superior Diabetes Treatment-Related Quality of Life scores related to pain and gastrointestinal symptoms.

Use of diabetes medications in adults with T2D and CVD in Japan: secondary analysis of the CAPTURE study

Introduction

The CAPTURE study estimated the global prevalence of established cardiovascular disease (CVD) and characterized the usage of glucose-lowering agents (GLAs) in adults with type 2 diabetes (T2D) across 13 countries. The purpose of this secondary analysis of data from the Japanese sites within CAPTURE (NCT03786406, NCT03811288) was to provide data about medication usage stratified by CVD status among Japanese participants with T2D.

Materials and methods

Data on GLA usage (including those with proven cardiovascular [CV] benefits) in Japanese participants with T2D managed in clinics or hospitals were collected and stratified by CVD subgroups.

Results

There were 800 Japanese participants in the CAPTURE study (n = 502 [no CVD group], n = 298 [CVD group], n = 268 [atherosclerotic CVD subgroup]). Oral antidiabetic agents and insulin were used by 88.5% and 23.4%, respectively, of participants overall. Among participants with established CVD, dipeptidyl peptidase-4 inhibitors (65.1%) were most frequently used, followed by biguanides (50.7%) and insulins (26.2%). The pattern was similar among participants with atherosclerotic CVD. A lower proportion of participants in the CVD group used glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT-2is) with proven CV benefits versus the no CVD group (GLP-1 RAs: 7.0% vs. 8.6%; SGLT-2is: 13.4% vs. 19.1%).

Conclusion

This analysis of the CAPTURE study provided a comprehensive overview of prescription patterns for the treatment of T2D in Japan. Use of GLAs with proven CV benefit was low, even in participants with established CVD, which was comparable to the findings from the global cohort.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-023-00638-w.

Insulin Requirements During Severe COVID-19 Were Relatively Low in Japanese Patients With Type 2 Diabetes: Two Case Reports

The global coronavirus disease 2019 (COVID-19) pandemic has caused myriad adverse effects on the pathology of other diseases. Numerous studies on COVID-19 have reported that, in patients with type 2 diabetes mellitus (T2DM) who have contracted severe COVID-19, glucose metabolism is exacerbated by multiple factors, such as severe inflammation, beta-cell dysfunction caused by the SARS-CoV-2 infection itself, corticosteroid therapy, vasopressor administration, and enteral or parenteral nutrition. Very high doses of insulin are often required in the acute phase of such patients; however, the factors that affect insulin requirements and to what extent remain unclear. A 50-year-old Japanese woman and a 67-year-old Japanese man, both with T2DM and obesity, were admitted to our hospital with severe COVID-19. Both patients required mechanical ventilation and were treated with dexamethasone and tocilizumab, an interleukin-6 (IL-6) receptor monoclonal antibody. Subcutaneous insulin injections failed to control the patients' hyperglycemia, requiring up to 1.83 and 1.81 units/kg/day of intravenous insulin, respectively. Insulin requirements were rapidly decreased with improvement of the respiratory condition, termination of dexamethasone, and discontinuation of tube feeding. Both patients were discharged with oral antidiabetic agents alone. We experienced two Japanese patients who achieved satisfactory glycemic control with a lower intravenous insulin dose than previous reports. Comparing the clinical factors with the previous literature, ethnic differences in insulin sensitivity and the administration of IL-6 receptor antibodies may have been related to the relatively low insulin requirements.

Impact of concomitant oral glucose-lowering medications on the success of basal insulin titration in insulin-naïve patients with type 2 diabetes: a systematic analysis

Basal insulin treatment for type 2 diabetes is usually initiated on a background of oral glucose-lowering medications (OGLM). We wanted to examine the influence of various OGLMs on fasting plasma glucose (FPG) and hemoglobin A_1c (HbA_1c) values achieved after titration. A PubMed literature search retrieved 42 publications (clinical trials introducing basal insulin in 17 433 insulin-naïve patients with type 2 diabetes on a defined background of OGLM) and reporting FPG, HbA_1c, target achievement, hypoglycemic events, and insulin doses. 60 individual study arms were grouped by OGLM (combinations) allowed during the titration process: (a) metformin only; (b) sulfonylureas only; (c) metformin and sulfonylureas; or (d) metformin and dipeptidyl peptidase-4 (DPP-4) inhibitors. For all OGLM categories, weighted means and SD were calculated for baseline and end-of-treatment FPG, HbA_1c, target achievement, incidence of hypoglycemic events, and insulin doses. Primary end point was a difference in FPG after titration between OGLM categories. Statistics: analysis of variance and post hoc comparisons. Sulfonylureas, alone or in combination with metformin, impair the titration of basal insulin (insulin doses 30%-40% lower, more hypoglycemic episodes), thus leading to poorer final glycemic control (p<0.05 for FPG and HbA_1c after titration). Conversely, adding a DPP-4 inhibitor to metformin is superior to metformin alone (p<0.05 for FPG and HbA_1c achieved) in patients with type 2 diabetes initiating basal insulin therapy. In conclusion, OGLM are a major determinant of the success of basal insulin therapy. Sulfonylureas impair, while DPP-4 inhibitors (added to metformin) may facilitate the achievement of ambitious fasting glucose targets. PROSPERO registration number CRD42019134821.

[Efficacy of treatment with glucagon-like peptide receptor agonists-1 in Asian patients with type 2 diabetes mellitus]

BACKGROUND

The projected 68% increase in patients with type 2 diabetes mellitus (T2D) in the upcoming decades and the specific pathophysiological course of the disease are critical factors for the development of optimal disease management tactics in the Asian population. It is now known that β-cell dysfunction is dominant in the pathogenesis of T2D in Asians. In a number of Asian countries, incretin therapy is the leading therapy.

AIM

To review literature on glucagon-like peptide-1 (GLP-1) secretion and clinical trial results of GLP-1 receptor agonist class (GLP-1RA) drugs as well as to evaluate their effectiveness in Asian population with T2D.

MATERIALS AND METHODS

A review of studies on pathophysiological aspects of GLP-1 secretion and evaluation of the efficacy of therapy with GLP-1RA preparations registered and used in clinical practice in Asian regions.

RESULTS

Several studies in Asian countries have shown that intact GLP-1 levels were significantly lower in both T2D patients and healthy Japanese volunteers; as well as in patients with impaired glucose tolerance. It is suggested that either impaired secretion of GLP-1 in the gut, accelerated processing by dipeptidyl peptidase-4, or a combination of both are responsible for the decrease in GLP-1. The greater efficacy of GLP-1RA treatment in achieving glycemic control in Asian T2D patients was presented by Kim Y.G. et al. in a meta-analysis of 15 randomised controlled trials, the reduction in HbA1c on GLP-1RA treatment averaged -1.16% in Asian-dominated studies and -0.83% in non-Asian-dominated studies. In the PIONEER 9 clinical programme, similar results were obtained, with oral semaglutide having a more pronounced effect on glycaemic control in Japanese patients. Thus, the mean change in HbA 1c was -1.1%, 7 mg -1.5%, and 14 mg -1.7% at the 3 mg dose; whereas in the PIONEER 1 study in the global population, the mean change in HbA1c was -0.6%, -0.9% and -1.1% for 3, 7, 14 mg semaglutide, respectively. The PIONEER 10 study concluded that oral semaglutide was well tolerated by Japanese patients with T2D. Oral semaglutide reduced HbA1c (14 mg dose) and body weight (7 and 14 mg doses) more significantly compared to dulaglutide at 0.75 mg dose. Results of a pooled analysis of long-acting GLP-1RA showed a more significant reduction in cardiovascular event risk in the Asian subpopulation.

CONCLUSION

The presented review describes benefits in glycemic control as well as in the reduction of relative cardiovascular event risks with GLP-1RA treatment in the Asian population, which requires further in-depth research and implies optimal management tactics in patients with T2DM.

Treatment strategy for children and adolescents with type 2 diabetes-based on ISPAD Clinical Practice Consensus Guidelines 2022

The principles of treatment for children and adolescents with type 2 diabetes include dietary and exercise management. For dietary management, a relatively modest dietary regimen with an appropriate energy source composition is recommended. Moderate- to vigorous-intensity aerobic activity is recommended for at least 60 min/d. Family members are encouraged to modify their lifestyles. Some patients fail to improve hyperglycemia through dietary and exercise management and eventually require pharmacological treatment. If the patient is metabolically stable (HbA1c level < 8.5% [69 mmol/mol]), metformin is the first-line treatment of first choice. In a case with ketosis or HbA1c of more than 8.5% (69 mmol/mol), insulin will be required initially with once daily basal insulin (0.25-0.5 units/kg). The goal of the initial treatment is to attain an HbA1c level < 7.0% (53 mmol/mol). If the glycemic goal is not attained, the addition of a second agent should be considered. However, the use of antihyperglycemic drugs in pediatric patients is limited in most countries. Therefore, the efficacy and safety of these drugs used in adult patients, including GLP-1 receptor agonists and SGLT2 inhibitors, should be evaluated in pediatric patients worldwide.

Common metabolic features of hypertension and type 2 diabetes

Hypertension and type 2 diabetes frequently coexist, suggesting that the two diseases have common pathophysiological bases. This review describes the pathophysiological mechanisms of how type 2 diabetes is frequently associated with hypertension. Multiple common factors mediate between both diseases. Factors that induce both type 2 diabetes and hypertension include obesity-induced hyperinsulinemia, activation of the sympathetic nervous system, chronic inflammation, and changes in adipokines. Vascular complications resulting from type 2 diabetes and hypertension include endothelial dysfunction, vasodilation/constriction dysfunction of peripheral vessels and increased peripheral vascular resistance, arteriosclerosis, and chronic kidney disease. While many of these vascular complications are caused by hypertension, they also exacerbate the pathology of hypertension. In addition, insulin resistance in the vasculature blunts insulin-induced vasodilation and blood flow to skeletal muscle, which contributes to impaired glucose uptake to skeletal muscle and glucose intolerance. In obese and insulin-resistant patients, increase in the circulating fluid volume forms the major pathophysiology of elevated blood pressure. On the other hand, in non-obese and/or insulin-deficient patients, especially those in the middle- or later stages of diabetes, peripheral vascular resistance is the major pathophysiology of hypertension. The relationship between various factors involved in the pathogenesis of type 2 diabetes and hypertension. It should be noted that all the factors shown in the figure are not necessarily present simultaneously in every patient.

Current Knowledge on the Pathophysiology of Lean/Normal-Weight Type 2 Diabetes

Since early times, being overweight and obesity have been associated with impaired glucose metabolism and type 2 diabetes (T2D). Similarly, a less frequent adult-onset diabetes in low body mass index (BMI) people has been known for many decades. This form is mainly found in developing countries, whereby the largest increase in diabetes incidence is expected in coming years. The number of non-obese patients with T2D is also on the rise among non-white ethnic minorities living in high-income Western countries due to growing migratory flows. A great deal of energy has been spent on understanding the mechanisms that bind obesity to T2D. Conversely, the pathophysiologic features and factors driving the risk of T2D development in non-obese people are still much debated. To reduce the global burden of diabetes, we need to understand why not all obese people develop T2D and not all those with T2D are obese. Moreover, through both an effective prevention and the implementation of an individualized clinical management in all people with diabetes, it is hoped that this will help to reduce this global burden. The purpose of this review is to take stock of current knowledge about the pathophysiology of diabetes not associated to obesity and to highlight which aspects are worthy of future studies.

Three-Year Observation of Glucose Metabolism After Pancreaticoduodenectomy: A Single-Center Prospective Study in Japan

CONTEXT

The glucose tolerance of patients changes considerably from before to after pancreaticoduodenectomy wherein approximately half of the pancreas is resected.

OBJECTIVE

The aim of this prospective study was to investigate the incidence of and risk factors for diabetes after pancreaticoduodenectomy.

METHODS

This study is a part of an ongoing prospective study, the Kindai Prospective Study on Metabolism and Endocrinology after Pancreatectomy (KIP-MEP) study. Of the 457 patients enrolled to date, 96 patients without diabetes who underwent pancreaticoduodenectomy were investigated in this study. Preoperatively, 1 month post-pancreaticoduodenectomy, and every 6 months thereafter, the glucose metabolism and endocrine function were evaluated using the 75 g oral glucose tolerance test. Various other metabolic, endocrine, and exocrine indices were also examined over a period of up to 36 months.

RESULTS

Of the 96 patients analyzed in this study, 33 were newly diagnosed with diabetes. The cumulative diabetes incidence at 36 months following pancreaticoduodenectomy was 53.8%. The preoperative insulinogenic index and ΔC-peptide in the glucagon stimulation test were significantly lower in the progressors to diabetes than in the nonprogressors. Multivariate Cox regression analysis demonstrated that the insulinogenic index was the only significant risk factor for new-onset diabetes.

CONCLUSION

The majority of patients developed new-onset diabetes after pancreaticoduodenectomy, and a low value of the insulinogenic index was suggested to be a risk factor for diabetes. Preoperative assessment for the prediction of the onset of diabetes serves as useful information for patients and is important for postoperative glycemic control and diabetes management in patients who require pancreaticoduodenectomy.

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.

Hyperferritinemia Is a Predictor of Onset of Diabetes in Japanese Males Independently of Decreased Renal Function and Fatty Liver: A Fifteen-Year Follow-Up Study

Background

Type 2 diabetes is an important health concern worldwide. The disease etiology may depend on multiple environmental and genetic factors that cause insulin resistance, including dysregulation of iron storage. The goal of this study was to examine the relationship of the serum ferritin concentration with onset of diabetes over a long period.

Methods

Correlations of serum ferritin and metabolic markers with onset of diabetes mellitus were examined over 15 years in 150 males participating in a health screening program.

Results

HOMA-β showed a gradual significant decrease in the first 4 years in subjects with ferritin > 190 ng/mL (group H) compared to those with ferritin ≤ 190 ng/mL, but there was no difference in HOMA-R between these groups. A significant number of cases with onset of diabetes was observed over 15 years (hazard ratio (HR): 3.97), and obesity, fasting blood glucose level, hemoglobin A1c (HbA1c), HOMA-R, fasting immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) were all significant in univariate comparison between non-diabetes and diabetes-onset groups. In multivariate analysis, ferritin in group H (HR: 3.25), fatty liver (HR: 3.38), estimated glomerular filtration rate (eGFR) < 70 mL/min/1.73 m² (HR: 3.48) and high-density lipoprotein (HDL) < 40 mg/dL (HR: 2.61) were significant predictive factors for onset of type 2 diabetes mellitus.

Conclusions

These results suggest that the serum ferritin level is an important index for priority intervention in preventive medicine for reduction of onset of diabetes.

Imeglimin population pharmacokinetics and dose adjustment predictions for renal impairment in Japanese and Western patients with type 2 diabetes

Imeglimin is an orally administered first-in-class drug to treat type 2 diabetes mellitus (T2DM) and is mainly excreted unchanged by the kidneys. The present study aimed to define the pharmacokinetic (PK) characteristics of imeglimin using population PK analysis and to determine the optimal dosing regimen for Japanese patients with T2DM and chronic kidney disease (CKD). Imeglimin plasma concentrations in Japanese and Western healthy volunteers, and patients with T2DM, including patients with mild to severe CKD with an estimated glomerular filtration rate (eGFR) > 14 mL/min/1.73 m² were included in a population PK analysis. Pharmacokinetic simulations were conducted using a population PK model, and the area under concentration-time curve (AUC) was extrapolated with power regression analysis to lower eGFR. The influence of eGFR, weight, and age on apparent clearance and of dose on relative bioavailability were quantified by population PK analysis. Simulations and extrapolation revealed that the recommended dosing regimen based on the AUC was 500 mg twice daily (b.i.d.) for patients with eGFR 15-45 mL/min/1.73 m² , and 500 mg with a longer dosing interval was suggested for those with eGFR < 15. Simulations revealed that differences in plasma AUCs between Japanese and Western patients at the same dose were mainly driven by a difference in the eGFR and that the plasma AUC after 1,000 and 1,500 mg b.i.d. in Japanese and Western patients, respectively, was comparable in the phase IIb studies. These results indicate suitable dosages of imeglimin in the clinical setting of T2DM with renal impairment.

Islet microangiopathy and augmented β-cell loss in Japanese non-obese type 2 diabetes patients who died of acute myocardial infarction

AIMS/INTRODUCTION

Islets have microvessels that might develop pathological alterations similar to microangiopathy in type 2 diabetes patients. It remains unclear, however, whether the changes correlate with endocrine cell deficits or whether the presence of macroangiopathy influences the islet microvasculature in Japanese type 2 diabetes patients. In this study, we characterized changes of the islet microvessels and endocrine cells in Japanese non-obese patients with type 2 diabetes who died of acute myocardial infarction (AMI).

MATERIALS AND METHODS

Clinical profiles and islet pathology were examined for 35 diabetes patients who died of AMI (DM + AMI) and 13 diabetes patients who were free from AMI (DM). A total of 13 age-matched, individuals without diabetes who died of AMI and 16 individuals without diabetes who were free from AMI were also studied. Pancreata were subjected to morphometric evaluation of islets, including microvascular alterations of immunostained sections.

RESULTS

Body mass index in DM + AMI was comparable to those in DM. Compared with DM, DM + AMI showed greater glycated hemoglobin levels, higher prevalence of renal failure, hypertension, smaller β-cell volume density and greater amyloid area. DM + AMI showed an increased microvascular area and density compared with other groups. There was a significant increase in vascular basement membrane thickness and loss of pericytes in DM and DM + AMI compared with individuals without diabetes in each group, and the extent of thickening was correlated with the amyloid area and occurrence of β-cell loss in DM + AMI.

CONCLUSIONS

Islet microangiopathy was associated with augmented β-cell loss and amyloid deposition in non-obese Japanese type 2 diabetes patients who died of AMI.

Postprandial Metabolism and Physical Activity in Asians: A Narrative Review

The widespread benefits of physical activity in enhancing health and lowering the risk of non-communicable chronic diseases are well established across populations globally. Nevertheless, the prevalence of several lifestyle-related chronic diseases, including cardiovascular disease, varies markedly across countries and ethnicities. Direct ethnic comparative studies on the health benefits of physical activity are sparse and evidence-based physical activity guidelines are not ethnicity-specific. Indeed, physical activity guidelines in some Asian countries were developed primarily based on data from Western populations even though the magnitude of potential benefit may not be the same among different ethnic groups. Unfavorable diurnal perturbations in postprandial triglycerides and glucose are risk factors for cardiovascular disease. This narrative review summarizes differences in these risk factors primarily between individuals of Asian and white European descent but also within different Asian groups. Moreover, the variable effects of physical activity on mitigating risk factors among these ethnic groups are highlighted along with the underlying metabolic and hormonal factors that potentially account for these differences. Future ethnic comparative studies should include investigations in understudied ethnic groups, such as those of East Asian origin, given that the effectiveness of physical activity for ameliorating cardiovascular disease varies even among Asian groups.

Can fingernail quality predict bone damage in Type 2 diabetes mellitus? a pilot study

Type 2 diabetes mellitus (T2DM) adversely affects the normal functioning, intrinsic material properties, and structural integrity of many tissues, including bone. It is well known that the clinical utility of areal bone mineral density (aBMD) is limited to assess bone strength in individuals with T2DM. Therefore, there is a need to explore new diagnostic techniques that can better assist and improve the accuracy of assessment of bone tissue quality. The present study investigated the link between bone and fingernail material/compositional properties in type 2 diabetes mellitus (T2DM). For that, femoral head and fingernail samples were obtained from twenty-five adult female patients (with/without T2DM) with fragility femoral neck fractures undergoing hemi/total hip arthroplasty. Cylindrical cores of trabecular bone were subjected to micro-CT, and lower bone volume fraction was observed in the diabetic group than the non-diabetic group due to fewer and thinner trabeculae in individuals with T2DM. The material and compositional properties of bone/fingernail were estimated using nanoindentation and Fourier Transform Infrared Spectroscopy, respectively. Both bone/fingernails in T2DM had lower reduced modulus (E_r), hardness (H), lower Amide I and Amide II area ratio (protein content), higher sugar-to-matrix ratio, and relatively high carboxymethyl-lysine (CML) content compared with non-diabetic patients. Sugar-to-matrix ratio and relative CML content were strongly and positively correlated with HbA_1c for both bone/fingernail. There was a positive correlation between bone and fingernail glycation content. Our findings provide evidence that the degradation pattern of bone and fingernail properties go hand-in-hand in individuals with T2DM. Hence, the fingernail compositional/material properties might serve as a non-invasive surrogate marker of bone quality in T2DM; however, further large-scale studies need to be undertaken.

Diversity of pathophysiology in type 2 diabetes shown by islet pathology

The etiology of type 2 diabetes is multifactorial, in which environmental and genetic factors are involved to varying degrees. This suggests that its pathophysiology might vary depending on the individuals. Knowledge of the differences is critical, because these differences are directly linked to the care and treatment of the patients. Recent studies have attempted to carry out subclassifications of type 2 diabetes based on clinical and genetic differences. However, there is no pathological evidence to support these subclassifications. The pathophysiology of type 2 diabetes is generally divided into insulin resistance in peripheral tissues and pancreatic islet dysfunction. Among them, islet dysfunction causes a deficit in insulin secretion from β-cells. In particular, a deficit in insulin secretion is ascribed to a combination of disruption of the insulin secretory machinery and a decrease in β-cell volume in type 2 diabetes. Recent research has suggested that transdifferentiation and dedifferentiation are involved in the decrease in β-cell volume, and that it might change dynamically depending on the glucose metabolic state. However, it is possible that the numbers of islet cells are decreased in type 2 diabetes. In particular, the loss of endocrine cells due to islet amyloid deposits is an important pathological change in type 2 diabetes in humans. These results show that pathological changes of the islets can be different in each individuals with type 2 diabetes and reflect each pathophysiology, which is useful in establishing further subclassifications and developing tailor-made therapies for type 2 diabetes.

Alcohol consumption, tobacco smoking, and subsequent risk of renal cell carcinoma: The JPHC study

The effects of alcohol consumption and tobacco smoking on renal cell carcinoma (RCC) incidence have not been well‐investigated in Asian populations. Here, we evaluated these effects in a large Japanese prospective cohort. We collected data on eligible participants in the Japan Public Health Center‐based Prospective Study, and undertook multivariable‐adjusted Cox proportional hazards regression to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of RCC incidence. We identified 340 cases (230 men and 110 women) among the 105 663 eligible participants (50 262 men and 55 741 women), who were followed for an average of 19.1 years, with a cumulative total of 2 020 364 person‐years. A slightly inverse but nonsignificant association was observed between alcohol drinking and RCC incidence. In contrast, the risk of RCC was increased in those with heavy smoking (≥40 pack‐years) when men and women were combined (HR 1.50; 95% CI, 1.01‐2.25). We identified no significant association between alcohol consumption and RCC incidence. In contrast, heavy smoking (≥40 pack‐years) was associated with a significant increase in incidence.

Using a large prospective cohort in Japan, we evaluated the effects of alcohol consumption and tobacco smoking on renal cell carcinoma (RCC). Our analyses showed no significant association between alcohol consumption and RCC incidence. In contrast, heavy smoking (≥40 pack‐years) was associated with a significant increase in incidence.

Impact of triglycerides and waist circumference on insulin resistance and β-cell function in non-diabetic first-degree relatives of type 2 diabetes

BACKGROUND

Although there is abundant evidence indicating the relative contribution of insulin resistance (HOMA-IR) and β-cell dysfunction (HOMA-β) among first-degree relatives (FDRs) of Type 2 DM patients, few studies reported the association between HOMA-IR and HOMA-β with metabolic syndrome. Our objective was to evaluate the impact of metabolic syndrome factors on HOMA-IR, HOMA-β and glycoproteins in non-diabetic FDRs.

METHODS

In this study, 103 Yemeni male subjects aged 25-42 years, with BMI < 25 kg/m² were examined, 39 of whom were normal subjects with no family history of diabetes served as control and 64 subjects were non-diabetic FDRs of Type 2 DM patients.

RESULTS

Both glycoproteins, glycated haemoglobin (HbA1c) and fructosamine as well as insulin, HOMA-IR and HOMA-β were significantly (p = 4.9 × 10^-9; 6.0 × 10^-8; 6.6 × 10^-12; 1.3 × 10^-7; 5.5 × 10^-12, respectively) higher in non-diabetic FDRs as compared to control group. Fasting plasma glucose, though within normal range, were significantly (p = 0.026) higher in non-diabetic FDRs. Linear regression analysis showed that both TG and WC are the main metabolic syndrome factors that significantly increased HOMA-IR (B = 0.334, p = 1.97 × 10^-6; B = 0.024, p = 1.05 × 10^-5), HOMA-β (B = 16.8, p = 6.8 × 10^-5; B = 0.95, p = 0.004), insulin (B = 16.5, p = 1.2 × 10^-6; B = 1.19, p = 8.3 × 10^-6) and HbA1c (B = 0.001, p = 0.034; B = 0.007, p = 0.037).

CONCLUSION

Triglyceride and WC are the important metabolic syndrome factors associated with insulin resistance, basal β-cell function and insulin levels in non-diabetic FDR men of Type 2 DM patients. Moreover, FDRs showed insulin resistance with compensatory β-cell function (hyperinsulinaemia) suggesting that insulin resistance precede the development of pancreatic β-cell dysfunction in individuals at risk of Type 2 DM.

Investigation of Mechanical, Material, and Compositional Determinants of Human Trabecular Bone Quality in Type 2 Diabetes

CONTEXT

Increased bone fragility and reduced energy absorption to fracture associated with type 2 diabetes (T2D) cannot be explained by bone mineral density alone. This study, for the first time, reports on alterations in bone tissue's material properties obtained from individuals with diabetes and known fragility fracture status.

OBJECTIVE

To investigate the role of T2D in altering biomechanical, microstructural, and compositional properties of bone in individuals with fragility fracture.

METHODS

Femoral head bone tissue specimens were collected from patients who underwent replacement surgery for fragility hip fracture. Trabecular bone quality parameters were compared in samples of 2 groups, nondiabetic (n = 40) and diabetic (n = 30), with a mean duration of disease 7.5 ± 2.8 years.

RESULTS

No significant difference was observed in aBMD between the groups. Bone volume fraction (BV/TV) was lower in the diabetic group due to fewer and thinner trabeculae. The apparent-level toughness and postyield energy were lower in those with diabetes. Tissue-level (nanoindentation) modulus and hardness were lower in this group. Compositional differences in the diabetic group included lower mineral:matrix, wider mineral crystals, and bone collagen modifications-higher total fluorescent advanced glycation end-products (fAGEs), higher nonenzymatic cross-link ratio (NE-xLR), and altered secondary structure (amide bands). There was a strong inverse correlation between NE-xLR and postyield strain, fAGEs and postyield energy, and fAGEs and toughness.

CONCLUSION

The current study is novel in examining bone tissue in T2D following first hip fragility fracture. Our findings provide evidence of hyperglycemia's detrimental effects on trabecular bone quality at multiple scales leading to lower energy absorption and toughness indicative of increased propensity to bone fragility.

Effect of the FreeStyle Libre™ flash glucose monitoring system on glycemic control in individuals with type 2 diabetes treated with basal-bolus insulin therapy: An open label, prospective, multicenter trial in Japan

AIMS/INTRODUCTION

We investigated the effect of FreeStyle LibreTM on glycemic control in Japanese type 2 diabetes patients treated with basal-bolus insulin therapy.

MATERIALS AND METHODS

This prospective, 90-day single-arm study enrolled 94 adults with type 2 diabetes treated with insulin. A 14-day masked baseline phase was followed by an 11-week treatment phase during which participants used the device to monitor glucose levels. The primary end-point was time spent in hypoglycemia (<70 mg/dL) for baseline versus study end (days 76-90). Secondary end-points included other measures of glycemic control, along with patient satisfaction using the Japanese Diabetes Treatment and Satisfaction Questionnaire.

RESULTS

Time spent in hypoglycemia was low at baseline (0.51 ± 0.93 h/day) and did not significantly decrease at study end (0.47 ± 0.63 h/day, P = 0.6354). Time in range, time in hyperglycemia and estimated A1c all improved versus baseline (by +1.7 ± 3.0 h/day, -1.6 ± .4 h/day and -0.4 ± 0.8%, respectively, P < 0.0001 in each). Finger stick tests fell from 2.9 ± 1.3 to 1.9 ± 1.4/day, and mean scanning frequency during the intervention phase was 11.3/day. The mean treatment satisfaction score increased by 11.8 ± 5.3 (P < 0.0001). Two severe hypoglycemia-related adverse events were reported; one of which was possibly related to the device. Three participants reported mild device-related skin trauma, site discomfort or subcutaneous bleeding.

CONCLUSIONS

Use of FreeStyle Libre by Japanese type 2 patients diabetes treated with basal-bolus insulin therapy showed a low baseline of hypoglycemia, and enabled improved glycemic control and treatment satisfaction.

Do East Asians With Normal Glucose Tolerance Have Worse β-Cell Function? A Meta-Analysis of Epidemiological Studies

BACKGROUND

The difference in the relationship between β-cell function and insulin resistance among Africans, Caucasians and East Asians with normal glucose tolerance (NGT) was not well investigated.

METHODS

We searched PubMed and Web of Science with keywords and identified studies that used the homeostasis model assessment (HOMA) model to evaluate β-cell function (HOMA-B) and insulin sensitivity/resistance (HOMA-S/HOMA-IR) in certain ethnic groups. We used random-effect model to pool data of HOMAs and compared the combined data among the three ethnic groups using subgroup analysis. Linear regression analysis was used to estimate the coefficient of HOMA-S on HOMA-B in these ethnic groups.

RESULTS

We evaluated pooled data of HOMAs in eight African, 26 Caucasian, and 84 East Asian cohorts with NGT, and also 2,392, 6,645 and 67,317 individuals, respectively. The three ethnic groups had distinct HOMA-B but similar HOMA-IR. The regression coefficient of lnHOMA-B on lnHOMA-S was different between Africans and Caucasians (-1.126 vs -0.401, P = 0.0006) or East Asian (-1.126 vs -0.586, P = 0.0087), but similar between Caucasians and East Asians (-0.401 vs -0.586, P = 0.1282). The coefficient in all ethnic groups was similar when age, BMI, and gender were adjusted (African vs Caucasian P = 0.0885, African vs East Asian P = 0.1092, and Caucasian vs East Asian P = 0.6298).

CONCLUSIONS

In subjects with NGT, East Asians had lower HOMA-B but similar β-cell response relative to insulin resistance with Caucasians and Africans when age, BMI, and gender were controlled. This result may challenge the allegation that there was an Asian-specific diabetes phenotype with worse β-cell function.

Development of HFD-Fed/Low-Dose STZ-Treated Female Sprague-Dawley Rat Model to Investigate Diabetic Bone Fragility at Different Organization Levels

Type 2 diabetes (T2D) adversely affects the normal functioning, intrinsic material properties, and structural integrity of many tissues, and bone fragility is one of them. To simulate human T2D and to investigate diabetic bone fragility, many rodent diabetic models have been developed. Still, an outbred genetically normal nonobese diabetic rat model is not available that can better simulate the disease characteristics of nonobese T2D patients, who have a high prevalence in Asia. In this study, we used a combination treatment of high-fat diet (4 weeks, 58% kcal as fat) and low-dose streptozotocin (STZ; 35 mg/kg i.p. at the end of the fourth week) to develop T2D in female Sprague-Dawley (SD) rats. After 8 weeks of the establishment of the T2D model, the femoral bones were excised after euthanizing rats (animal age approximately 21 to 22 weeks; n = 10 with T2D, n = 10 without diabetes). The bone microstructure (μCT), mechanical, and material properties (three-point bending, cyclic reference point indentation, nanoindentation), mean mineral crystallite size (XRD), bone composition (mineral-to-matrix ratio, nonenzymatic cross-link ratio [NE-xLR], Fourier transform-infrared microspectroscopy), and total fluorescent advanced glycation end products were analyzed. We found that diabetic bone had reduced whole-bone strength and compromised structural properties (μCT). The NE-xLRs were elevated in the T2D group, and strongly and negatively correlated with postyield displacement, which suggests bone fragility was caused by a lack of glycation control. Along with that, the decreased mineral-to-matrix ratio and modulus, increased indentation distance increase, and wider mineral crystallite size in the T2D group were evidence that the diabetic bone composition and material properties had changed, and bone became weaker with a tendency to easily fracture. Altogether, this model simulates the natural history and metabolic characteristics of late-stage T2D (insulin resistance and as disease progress develops, hypoinsulinemia) for nonobese young (and/or adolescent) T2D patients (Asians) and provides potential evidence of diabetic bone fragility at various organization levels. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Alcohol-induced impaired insulin secretion in a Japanese population: 5-year follow up in the Gifu Diabetes Study

AIMS/INTRODUCTION

Although moderate alcohol consumption lowers the risk of type 2 diabetes in European populations, the same cannot be assumed for Japanese patients with diabetes related to low insulin secretion rather than resistance. We aimed to evaluate the effects of daily alcohol consumption on glucose tolerance and diabetes development risk in Japanese populations.

MATERIALS AND METHODS

This retrospective study randomly enrolled 452 men and 659 women aged 40-78 years in 2005 (Gifu, Japan). The participants completed a 75-g oral glucose tolerance test and medical questionnaire. The homeostasis model assessment of insulin resistance, homeostasis model assessment of β-cell function and insulinogenic index were used to estimate insulin sensitivity and secretion. The relationships between alcohol consumption and these parameters were analyzed using logistic regression after adjusting for potential confounders. The 5-year changes in hemoglobin A1c levels were also evaluated.

RESULTS

The adjusted odds ratios for elevated homeostasis model assessment of β-cell function values (<40%) in the 0-19.9 g/day, 20.0-39.9 g/day and ≥ 40 g/day alcohol consumption groups were 0.98, 1.46 and 2.68, respectively. Alcohol consumption induced a significant decrease in the insulin secretion level among the ≥40 g/day drinkers, especially in men. However, there was no risk of increased insulin resistance based on the homeostasis model assessment of insulin resistance (<2.5) results. The 5-year risk of elevated hemoglobin A1c levels (≥6.5%) was increased according to increase in alcohol consumption in both men and women.

CONCLUSIONS

Daily alcohol consumption was associated with reduced insulin secretion and an increased diabetes development risk in Japanese populations.

Dietary survey in Japanese patients with type 2 diabetes and the influence of dietary carbohydrate on glycated hemoglobin: The Sleep and Food Registry in Kanagawa study

AIMS/INTRODUCTION

The present study investigated the relationship between the macronutrient energy ratio, dietary carbohydrate and glycated hemoglobin levels in Japanese patients with type 2 diabetes, to generate a potential optimal dietary intake of macronutrients for such patients.

MATERIALS AND METHODS

In total, 3,032 patients participating in the Sleep and Food Registry in Kanagawa study were evaluated. Their diets were assessed for macronutrient content through a brief self-administered dietary history questionnaire. Relevant biochemical assays were carried out.

RESULTS

The mean energy intake (±standard deviation) was 1,711 ± 645 kcal/day. The proportion of energy supplied by protein, fat and carbohydrate were 16.3, 26.8 and 52.3%, respectively. Total fiber intake was 12.6 ± 5.7 g/day. The high glycated hemoglobin (HbA1c) group (HbA1c >8%) had significantly lower protein and higher carbohydrate intake than the low HbA1c group (HbA1c <6.5%). Higher HbA1c levels were positively correlated with unfavorable metabolic factors, including elevated body mass index and excess carbohydrate intake, and negatively correlated with age, protein intake and fiber intake. Multiple regression analysis showed a significant association between HbA1c and carbohydrate intake after adjusting for sex, age and body mass index (0.104, P < 0.0001). Additionally, patients within the uppermost tertile for the percentage of total energy intake from carbohydrate (>60%) were most likely to have high HbA1c levels. HbA1c was significantly correlated with carbohydrate (%E) in all age groups and in patients taking one or two antidiabetic drugs.

CONCLUSIONS

The dietary carbohydrate:energy ratio has a positive correlation with HbA1c, suggesting that avoiding excessive carbohydrate intake (>60%) might help foster glycemic control.

Reduction in glucose fluctuations in elderly patients with type 2 diabetes using repaglinide: A randomized controlled trial of repaglinide vs sulfonylurea

AIMS/INTRODUCTION

Glinides are antidiabetic drugs that enhance the early phase of insulin secretion, but have been considered to be less effective at lowering blood glucose than sulfonylureas. However, glinides show a lower risk of hypoglycemia and a greater effect on postprandial hyperglycemia, and are particularly recommended for use in elderly patients with type 2 diabetes. We investigated the efficacy and safety of repaglinide compared with sulfonylurea for the treatment of elderly patients.

MATERIALS AND METHODS

In the present multicenter, prospective, randomized, open-label, controlled trial, 57 elderly lean patients with type 2 diabetes who were being treated with sulfonylureas were studied. They were either switched to repaglinide (Repa group) or continued a sulfonylurea (SU group) for 12 weeks. The primary outcome comprised the change in glycemic control, and among the secondary outcomes was the presence of hypoglycemia and drug compliance.

RESULTS

Although glycated hemoglobin (HbA1c) was not significantly different between the two groups (SU +0.02% vs Repa -0.07%), greater improvements in the glycated albumin (GA) and GA to HbA1c ratio (GA/HbA1c) were observed in the Repa group (ΔGA, SU +0.12% vs Repa -1.15%; ΔGA/HbA1c, SU +0.01 vs Repa -0.13; each P < 0.01) without increasing hypoglycemia. When the Repa group was subdivided according to whether GA improved, the SU dose before switching to repaglinide was significantly smaller and the homeostatic model assessment of β-cell function was significantly higher in the GA improvement subgroup.

CONCLUSIONS

Switching from SU to Repa improved GA and GA/HbA1c, and had favorable effects on glucose fluctuation in elderly patients with type 2 diabetes.

Prevalence of Diabetes Mellitus among Roma Populations-A Systematic Review

Background: The aim of this study was to estimate the prevalence of diabetes mellitus in the Roma population and compare it to the prevalence in the Caucasian population. Methods: Using the words “Roma”, “Gypsies”, “Romani”, and ”traveler” in combination with “diabetes, “metabolic syndrome”, “cardiovascular disease” and “health status” we searched the MEDLINE, Pubmed and Scopus databases for articles in English that focused on the prevalence of diabetes mellitus among Roma populations published until December 2017. Results: Five studies met the inclusion criteria. The results of four of them suggested a higher prevalence of diabetes among Romani compared to Caucasians but none of them reached the standards regarding representative samples and number of cases for a conclusive result. Conclusion: Although some of the existing studies suggest a substantial prevalence of diabetes among Roma populations and even a higher risk of developing diabetes for Roma persons compared to Caucasians, the number of published literature on this topic remains very low and insufficient in design and number of participants to draw any conclusions.

Blood glucose profiles in East Asian and Caucasian injection-naive patients with type 2 diabetes inadequately controlled on oral medication: a pooled analysis

AIM

The primary objective of this study was to compare blood glucose (BG) excursions between East Asian and Caucasian patients with type 2 diabetes mellitus (T2DM) who were injection-naive, had inadequate glycemic control with oral antihyperglycemic medications, and who required initiation with injectable therapy.

METHODS

This retrospective pooled analysis included individual patient data from completed clinical trials (Insulin lispro injection/dulaglutide development programs, first patient visit ≥1997). All included patients were ≥18 years, were East Asian or Caucasian, and had data for self-monitored BG at baseline. The primary outcome, BG excursion at baseline (least-squares mean, standard error), was compared between patient groups using an analysis of covariance with race as the fixed effect. Independent covariates included baseline body weight, baseline HbA1c, age, and duration of T2DM.

RESULTS

Caucasian (n = 6779) and East Asian (n = 1638) patients from 21 trials were included. BG excursions were significantly higher for East Asian than Caucasian patients at breakfast (4.03 [0.075] vs 2.59 [0.045] mmol/L), lunch (3.37 [0.080] vs 1.43 [0.049] mmol/L), and dinner (3.16 [0.080] vs 1.74 [0.047] mmol/L) (P < 0.001 adjusted analyses). Similar findings were observed for the unadjusted analyses. At each time point, postprandial BG was significantly higher for East Asian than Caucasian patients (with adjusted and unadjusted analyses).

CONCLUSION

These findings suggest that BG excursion and postprandial BG are higher among East Asian patients with T2DM than Caucasian patients. In addition, these findings may help clinicians select appropriate treatments for East Asian patients with T2DM who require injection therapy.

Glucose excursions and hypoglycemia in patients with type 2 diabetes treated with mitiglinide/voglibose versus glimepiride: A randomized cross-over trial

BACKGROUND

Glucose excursions and hypoglycemia are associated with cardiovascular complications. However, no studies have evaluated glucose excursions and the frequency of hypoglycemia in patients treated with mitiglinide/voglibose versus glimepiride as add-on to dipeptidyl peptidase-4 inhibitor therapy.

METHODS

This cross-over trial included 20 patients with type 2 diabetes. After initiating vildagliptin 100 mg, patients were randomly assigned to receive mitiglinide 10 mg/voglibose 0.2 mg three times daily for 3 days followed by glimepiride 1 mg once daily for the subsequent 3 days as add-on therapy, or vice versa. Glucose excursions and hypoglycemia frequency were measured using 24-h continuous glucose monitoring. Metabolic profile changes were evaluated using a meal tolerance test.

RESULTS

The mean glucose levels in the mitiglinide/voglibose and glimepiride phases were identical (8.01 vs 8.24 mmol/L, respectively). However, during the mitiglinide/voglibose phase compared with the glimepiride phase, the standard deviation of glucose (1.30 vs 2.10 mmol/L; P < 0.001), mean amplitude of glycemic excursions (3.47 vs 5.28 mmol/L; P < 0.001), M-value (24.6 vs 70.0; P < 0.001), continuous overlapping net glycemic action for a 1-h time interval (22.6 vs 31.0; P < 0.001), and area under the curve >10 mmol/L (0.18 vs 0.52 mmol/L per h; P < 0.001) were significantly lower. Hypoglycemia (glucose <3.8 mmol/L) was not observed during the mitiglinide/voglibose phase, but occurred 0.35 times/day in those taking glimepiride. Moreover, the mitiglinide/voglibose phase had higher premeal and lower post-meal glucose levels than the glimepiride phase.

CONCLUSIONS

Adding mitiglinide/voglibose to vildagliptin therapy results in more efficient postprandial glucose control and less hypoglycemia than adding glimepiride.

Submucosal fat accumulation in human colorectal tissue and its association with abdominal obesity and insulin resistance

Background

In addition to visceral fat, peripheral ectopic fat accumulation is suggested to play a role in the pathophysiology of metabolic syndrome, which is known to be associated with not only cardiovascular diseases and type 2 diabetes mellitus but also colorectal cancer.

Objective

This study aims to clarify whether there is ectopic fat accumulation in human colorectal tissue in association with metabolic syndrome or its components such as abdominal obesity and insulin resistance.

Methods

Lipid contents of colorectal tissue were measured in 27 patients with colorectal polyp excised endoscopically. In addition, lipid droplets were immunohistochemically estimated using anti-perilipin antibody in 32 patients with colorectal cancer resected surgically.

Results

Increasing tissue triglyceride/phospholipid ratio was associated with increasing body mass index, fasting plasma insulin level and homeostasis model assessment as an index of insulin resistance (HOMA-IR), and also decreasing serum adiponectin level. Lipid droplets were observed in the submucosal region of colorectal tissue. The amount of lipid droplets was associated with increasing body mass index, waist circumference and visceral fat area.

Conclusion

This study showed the presence of submucosal fat accumulation in human colorectal tissue and its association with abdominal obesity and insulin resistance.

Fast-acting insulin aspart in Japanese patients with type 1 diabetes: Faster onset, higher early exposure and greater early glucose-lowering effect relative to insulin aspart

INTRODUCTION

Fast-acting insulin aspart (faster aspart) is insulin aspart (IAsp) in a new formulation with two added excipients (niacinamide and L-arginine) in order to obtain accelerated absorption after subcutaneous dosing. The present study compared the pharmacokinetic/pharmacodynamic characteristics of faster aspart vs IAsp in Japanese patients with type 1 diabetes.

MATERIALS AND METHODS

In a randomized, double-blind, cross-over design, 43 participants were given faster aspart and IAsp (0.2 U/kg single dose) at two separate dosing visits. Frequent pharmacokinetic blood sampling was carried out, and pharmacodynamics were assessed using an automated euglycemic clamp lasting for a maximum of 12 h after dosing (target 5.5 mmol/L).

RESULTS

Faster aspart showed onset of appearance approximately twice-as-fast vs IAsp (least squares means: 3.0 vs 7.1 min; estimated treatment difference -4.1 min, 95% confidence interval [CI]: -5.0, -3.2; P < 0.001) and onset of action occurring approximately 5 min earlier (20.2 vs 25.5 min; estimated treatment difference -5.3 min, 95% CI: -8.4, -2.2; P = 0.001). Within the first 30 min post-dose, both exposure (area under the curve [AUC]IAsp,0-30 min ) and glucose-lowering effect (AUCGIR,0-30 min ) were approximately twofold greater for faster aspart vs IAsp (P < 0.001 and P = 0.002, respectively). Bioavailability of faster aspart was similar to IAsp (AUCIAsp,0-t ; estimated treatment ratio 0.99, 90% CI: 0.96-1.02), whereas the total glucose-lowering effect (AUCGIR,0-t ) was slightly lower for faster aspart vs IAsp (estimated treatment ratio 0.93, 95% CI: 0.87-0.99, P = 0.020).

CONCLUSIONS

Faster aspart showed faster onset, higher early exposure and a greater early glucose-lowering effect relative to IAsp in Japanese patients with type 1 diabetes, in accordance with previous findings in Caucasian type 1 diabetes patients.

Association between alcohol consumption and incidence of impaired insulin secretion and insulin resistance in Japanese: The Saku study

AIMS

To investigate the effect of alcohol consumption on impaired insulin secretion and insulin resistance in Japanese.

METHODS

The participants in this 5-year cohort study were 2100 Japanese aged 30-74 years without type 2 diabetes mellitus, impaired insulin secretion, or insulin resistance who underwent a medical checkup including 75-g OGTT between April 2008 and March 2009 at Saku Central Hospital. Alcohol consumption was categorized as follows: non-drinker (0 g/week), light drinker (1-139 g/week in men and 1-69 g/week in women), moderate drinker (140-274 g/week in men and 70-139 g/week in women) and heavy drinker (≥275 g/week in men and ≥140 g/week in women). The hazard ratios (HRs) and 95% CIs among light to heavy drinkers for incidence of impaired insulin secretion (insulinogenic index ≤51.7) and insulin resistance (HOMA-IR ≥ 2.5), detected by an OGTT at the time of a follow-up medical checkup before the end of March 2014, were estimated by multivariable adjusted Cox proportional hazard models as reference values for non-drinkers.

RESULTS

There were 708 cases of impaired insulin secretion and 191 cases of insulin resistance. The HRs (95% CIs) for impaired insulin secretion in light, moderate and heavy drinkers were 1.16 (0.96-1.40), 1.35 (1.07-1.70) and 1.64 (1.24-2.16), respectively (P for trend <0.001). For insulin resistance, the HRs were 1.22 (0.84-1.76), 1.42 (0.91-2.22) and 1.59 (0.96-2.65), respectively (P for trend = 0.044).

CONCLUSION

Alcohol consumption was positively associated with the incidence of both impaired insulin secretion and insulin resistance.

Open-label, randomized study comparing basal insulin peglispro and insulin glargine, in combination with oral antihyperglycemic medications, in insulin-naïve Asian patients with type 2 diabetes

INTRODUCTION

The present phase 3, randomized, open-label study compared the efficacy and safety of basal insulin peglispro with insulin glargine after 26 weeks of treatment when added to oral antihyperglycemic medications in insulin-naïve Asian patients with type 2 diabetes.

MATERIALS AND METHODS

The primary objective was to show non-inferiority of the change in glycated hemoglobin from baseline to 26 weeks.

RESULTS

At 26 weeks, insulin peglispro was non-inferior to glargine, meeting the primary objective. Patients receiving insulin peglispro (n = 192) showed a greater reduction in glycated hemoglobin from baseline compared with glargine (n = 196); -1.6 vs -1.4%, P = 0.005) and in fasting serum glucose (-61.2 vs -54.8 mg/dL, P = 0.02). A significantly higher proportion of patients receiving insulin peglispro achieved glycated hemoglobin <7% (57 vs 44%, P = 0.012). Insulin peglispro patients showed significantly less weight gain from baseline (1.1 vs 1.6 kg, P = 0.03). Relative rates (insulin peglispro/glargine) of total and nocturnal hypoglycemia through 26 weeks were 1.06 (P = 0.67) and 0.7 (P = 0.10), respectively. Significantly more insulin peglispro-treated patients experienced adverse events compared with glargine-treated patients (P = 0.042). Alanine aminotransferase and aspartate aminotransferase were significantly increased from baseline with insulin peglispro compared with glargine at week 26 (3.5 vs -4.6 IU/L and 2.8 vs -1.5 IU/L, respectively; P < 0.001). The incidence of injection site reactions was low and did not differ between the treatments.

DISCUSSION

Insulin peglispro provided better glycemic control vs glargine with no differences in hypoglycemia and increased aminotransferases in insulin-naïve Asian patients with type 2 diabetes.

Obesity, Diabetes, and Acute Coronary Syndrome: Differences Between Asians and Whites

BACKGROUND

Most diabetes and cardiovascular studies have been conducted in white patients, with data being extrapolated to other population groups.

METHODS

For this analysis, patient-level data were extracted from 5 randomized clinical trials in patients with acute coronary syndrome; we compared obesity levels between Asian and white populations, stratified by diabetes status. By using an adjusted Cox proportional hazards model, hazard ratios (HRs) for cardiovascular outcomes after an acute coronary syndrome were determined.

RESULTS

We identified 49,224 patient records from the 5 trials, with 3176 Asians and 46,048 whites. Whites with diabetes had higher body mass index values than those without diabetes (median 29.3 vs 27.2 kg/m²; P < .0001), whereas Asians with diabetes and without diabetes had similar body mass index (24.7 vs 24.2 kg/m²). Asians with diabetes (HR, 1.63; 95% confidence interval [CI], 1.32-2.02), whites with diabetes (HR, 1.15; 95% CI, 1.06-1.25), and Asians without diabetes (HR, 1.36; 95% CI, 1.14-1.64) had higher rates of the composite of death, myocardial infarction, or stroke at 30 days than whites without diabetes. Asians with diabetes (HR, 1.84; 95% CI, 1.47-2.31), whites with diabetes (HR, 1.47; 95% CI, 1.33-1.62), and Asians without diabetes (HR, 1.38; 95% CI, 1.11-1.73) had higher rates of death at 1 year compared with whites without diabetes. There were no significant interactions between race and diabetes for ischemic outcomes.

CONCLUSIONS

Although Asians with diabetes and acute coronary syndrome are less likely to be obese than their white counterparts, their risk for death or recurrent ischemic events was not lower.

Weekly glucagon-like peptide-1 receptor agonist albiglutide as monotherapy improves glycemic parameters in Japanese patients with type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled study

AIMS/INTRODUCTION

The present phase 3, randomized, double-blind 24-week study with extension to 1 year assessed the efficacy and safety of albiglutide compared with placebo in Japanese patients with type 2 diabetes mellitus inadequately controlled by diet and exercise with or without a single oral antidiabetic drug.

MATERIALS AND METHODS

Patients received weekly albiglutide 30 mg (n = 160), albiglutide 50 mg (n = 150) or a placebo switched to albiglutide 30 mg after 24 weeks (n = 77). Open-label daily liraglutide 0.9 mg (n = 103) was included as a reference. Oral antidiabetic drug use was discontinued before baseline. The primary end-point was 24-week change from baseline in glycated hemoglobin (HbA1c). Secondary end-points included fasting plasma glucose, bodyweight and adverse events.

RESULTS

At 24 weeks, mean HbA1c changes from baseline were -1.10, -1.30, and 0.25% for albiglutide 30, 50 mg and placebo, respectively (P vs placebo <0.0001 for both albiglutide doses), -1.19% for liraglutide. Decreases in HbA1c with albiglutide were sustained through the study. Mean fasting plasma glucose decreased by ≥20 mg/dL, and the mean change in bodyweight was ≤0.5 kg through 1 year across groups. Most commonly reported adverse events were nasopharyngitis, constipation and nausea. The incidence of adverse events was higher in active treatment groups than in the placebo group. Few hypoglycemia events were reported; no patient withdrew as a result of hypoglycemia. No new safety signals were detected.

CONCLUSIONS

Albiglutide monotherapy achieved clinically significant decreases in HbA1c and fasting plasma glucose with good tolerability in Japanese patients with type 2 diabetes mellitus inadequately controlled by diet and exercise with or without a single oral antidiabetic drug.

S-Equol Activates cAMP Signaling at the Plasma Membrane of INS-1 Pancreatic β-Cells and Protects against Streptozotocin-Induced Hyperglycemia by Increasing β-Cell Function in Male Mice

Background:S-equol, which is enantioselectively produced from daidzein by gut microbiota, has been suggested as a chemopreventive agent against type 2 diabetes mellitus (T2DM), but the underlying mechanisms remain unclear.Objective: We investigated the effects of S-equol on pancreatic β-cell function.Methods: β-Cell growth and insulin secretion were evaluated with male Institute of Cancer Research mice and isolated pancreatic islets from the mice, respectively. The mechanisms by which S-equol stimulated β-cell response were examined in INS-1 β-cells. The effect of S-equol treatment on β-cell function was assessed in low-dose streptozotocin-treated mice. S-equol was used at 10 μmol/L for in vitro and ex vivo studies and was administered by oral gavage (20 mg/kg, 2 times/d throughout the experimental period) for in vivo studies.Results:S-equol administration for 7 d increased Ki67-positive β-cells by 27% (P < 0.01) in mice. S-equol enantioselectively enhanced glucose-stimulated insulin secretion in mouse pancreatic islets by 41% (P < 0.001). In INS-1 cells, S-equol exerted stronger effects than daidzein on cell growth, insulin secretion, and cAMP-response element (CRE)-mediated transcription. These S-equol effects were diminished by inhibiting protein kinase A. The effective concentration of S-equol for stimulating cAMP production at the plasma membrane was lower than that for phosphodiesterase inhibition. S-equol-stimulated CRE activation was negatively controlled by the knockdown of G-protein α subunit group S (stimulatory) and positively controlled by that of G-protein-coupled receptor kinase-3 and -6. Compared with vehicle-treated controls, S-equol gavage treatment resulted in an increase in β-cell mass of 104% (P < 0.05), a trend toward high plasma insulin concentrations (by 118%; P = 0.06), and resistance to hyperglycemia after streptozotocin treatment (78% of AUC after glucose challenge; P < 0.01). S-equol administration significantly increased the number of Ki67-positive proliferating β-cells by 62% (P < 0.01) and decreased that of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive apoptotic β-cells by 75% (P < 0.05).Conclusions: Our results show that S-equol boosts β-cell function and prevents hypoglycemia in mice, suggesting its potential for T2DM prevention.