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ABSTRACT Aims/Introduction Sodium–glucose cotransporter 2 (SGLT2) inhibitors effectively and safely reduce fasting and postprandial hyperglycemia while promoting weight loss. However, their unique mechanism of action contributes to concerns regarding their safety. We therefore carried out a large‐scale, non‐commercial, investigator‐initiated study on the safety and effectiveness of the SGLT2 inhibitor tofogliflozin. Materials and Methods This multicenter, open‐label, uncontrolled, prospective observational study was carried out at hospitals and clinics across Japan in participants aged ≥20 years who were SGLT2 inhibitor‐naïve and had an established diagnosis of type 2 diabetes. The primary endpoint was adverse drug reactions (ADRs) of special interest. Secondary endpoints included all other ADRs and adverse events, glycated hemoglobin (HbA1c), and weight loss. Results The study, carried out from June 2014 through February 2020, enrolled 11,480 participants from 1,103 medical institutions; 6,967 participants completed the 104‐week follow up. The most common ADRs of special interest were urinary and genital tract infections (1.53%), followed by volume depletion (1.25%). Hypoglycemia occurred in 27 participants (0.24%), adverse events in 1,054 (9.18%) and ADRs in 645 (5.62%). HbA1c decreased by 0.85% (95% confidence interval 0.82%–0.88%) and bodyweight decreased by 3.05 kg (95% confidence interval 2.94–3.17 kg). The HbA1c target was achieved by 51.70% of participants for target HbA1c

Sodium‐glucose cotransporter 2 inhibitors (SGLT2is) have been shown in cardiovascular outcome trials to reduce the risk of heart failure and major adverse cardiovascular as well as renal events in individuals with type 2 diabetes. Moreover, clinical evidence indicates that SGLT2i use reduces heart failure and chronic kidney disease (CKD) in east Asian patients with type 2 diabetes. Thus, SGLT2is might seem to be the preferred treatment for older patients with type 2 diabetes even in the presence of multiple comorbidities. However, older patients with type 2 diabetes may well have impaired physiological function, making the risk of certain adverse events higher than that in the general population. While a randomized clinical trial has been conducted to evaluate changes in skeletal muscle mass and function as well as those in cognitive function with SGLT2i use in older Japanese individuals with type 2 diabetes who are otherwise healthy, the safety of SGLT2is remains to be established among older individuals with type 2 diabetes also having impaired activity of daily living and/or cognitive impairment. Even so, international and domestic consensus reports recommend SGLT2is for patients with type 2 diabetes and heart failure, CKD, and/or cardiovascular diseases, and SGLT2is are being widely prescribed by general practitioners to older individuals with type 2 diabetes with little regard to the patient's comorbidities. We maintain that SGLT2i use in older patients with type 2 diabetes should be prescribed cautiously in consideration of the pathophysiology of the disease and the presence of complications and comorbidities as well as the individual's lifestyle.

Abstract Background Intramuscular adipose tissue (IMAT) formation derived from muscle fibro‐adipogenic progenitors (FAPs) has been recognized as a pathological feature of sarcopenia. This study aimed to explore whether genetic and pharmacological gastric inhibitory polypeptide (GIP) receptor antagonism suppresses IMAT accumulation and ameliorates sarcopenia in mice. Methods Whole body composition, grip strength, skeletal muscle weight, tibialis anterior (TA) muscle fibre cross‐sectional area (CSA) and TA muscle IMAT area were measured in young and aged male C57BL/6 strain GIP receptor (Gipr)‐knockout (Gipr−/−) and wild‐type (Gipr+/+) mice. FAPs isolated from lower limb muscles of 12‐week‐old Gipr+/+ mice were cultured with GIP, and their differentiation into mature adipocytes was examined. Furthermore, TA muscle IMAT area and fibre CSA were measured in untreated Gipr−/− mice and GIP receptor antagonist‐treated Gipr+/+ mice after glycerol injection into the TA muscles. Results Body composition analysis revealed that 104‐week‐old Gipr−/− mice had a greater proportion of lean tissue mass (73.7 ± 1.2% vs. 66.5 ± 2.7%, P

Abstract Aims/Introduction The EMPA‐REG OUTCOME® trial demonstrated benefits of empagliflozin, a sodium‐glucose cotransporter‐2 inhibitor (SGLT2i), on cardiovascular, renal outcomes and all‐cause mortality in patients with type 2 diabetes and established cardiovascular disease. The EMPRISE study program evaluates how these effects translate in a broad population of patients with type 2 diabetes in routine clinical care across countries. Materials and Methods The study included patients ≥18 years with type 2 diabetes initiating empagliflozin or any dipeptidyl peptidase‐4 inhibitors (DPP‐4i) from large administrative databases in Japan, South Korea, and Taiwan. Propensity score‐matched (1:1) ‘as‐treated’ analyses comparing the risk of cardiovascular outcomes and all‐cause mortality between empagliflozin and DPP‐4i use were performed in each country. Pooled hazard ratios (pHR) with 95% confidence intervals (CI) were computed using random effects meta‐analysis models comparing both empagliflozin and SGLT2i with DPP‐4i use, respectively. Intention‐to‐treat and subgroup analyses in patients with/without cardiovascular disease and in patients receiving 10 mg empagliflozin were performed. Results The study included 28,712 and 70,233 matched patient pairs for empagliflozin/DPP‐4i and SGLT2i/DPP‐4i analyses, respectively. The risk of composite outcomes including (i) hospitalization for heart failure (HHF) and all‐cause mortality was lower with empagliflozin (pHR 0.76, 95% CI 0.67–0.86) and SGLT2i (0.71, 0.65–0.77); (ii) combined myocardial infarction, stroke, and all‐cause mortality was also lower with empagliflozin (0.74, 0.61–0.88) and SGLT2i (0.69, 0.60–0.78) compared to DPP‐4i. The intention‐to‐treat and three subgroup analyses were consistent with results of the main analyses. Conclusions The results suggest that both empagliflozin and SGLT2i compared with DPP‐4i are associated with a lower risk of cardiovascular events and all‐cause mortality in routine clinical care in East Asia.

ABSTRACT Aims/Introduction This study was designed and carried out to investigate the association of dipeptidyl peptidase‐4 inhibitor (DPP‐4i) use with pancreatic cancer (PC) in individuals with diabetes in Japan. Materials and Methods The JMDC Claims Database, which contains the medical and prescription information of Japanese employment‐based health insurance programs, was used. The primary outcome was duration to the first occurrence of PC (International Classification of Diseases 10th Revision code C25), both all and hospitalized, from prescription of DPP‐4is or other oral glucose‐lowering agents (GLAs). Results Individuals with diabetes who received DPP‐4is (n = 61,430) or other oral GLAs (n = 83,304) were analyzed. Follow‐up periods (median [interquartile range]) were 17 months (8–33) for DPP‐4is and 14 months (7–28) for other oral GLAs. Kaplan–Meier curve analysis to determine the duration of first use of DPP4i or other oral GLA to diagnosis of PC disclosed no differences between the two groups in duration to all or hospitalized PC (log‐rank test: all, P = 0.7140; hospitalized, P = 0.3446). Cox proportional hazards models showed that use of DPP‐4is did not affect the PC risk adjusted for medications, age, sex and risk comorbidities (all, hazard ratio 1.1, 95% confidence interval 0.8–1.3, P = 0.6518; hospitalized, hazard ratio 1.1, 95% confidence interval 0.8–1.4, P = 0.6662). Similar results were obtained when individuals with ≥2 years oral GLA treatment and those with medical checkup data (e.g., smoking or drinking habit) available were analyzed. Conclusion This database study shows that there is not a significant PC risk due to DPP‐4i treatment in individuals with diabetes in Japan, but larger studies with longer follow up are required to confirm these findings.

Abstract Aims/Introduction The aim of this study was to develop a scale to evaluate disease stigma in patients with lifestyle‐related chronic non‐communicable diseases (LCNCDs), which we named the Kanden Institute Stigma Scale (KISS), and to consider its possible clinical application for patients with diabetes. Materials and methods An initial 90 questions were drafted and categorized into six subscales according to the manifestations of stigma. The final version of the KISS was developed as a 24‐item questionnaire comprising four items for each subscale. Results A total of 539 outpatients including 452 patients with diabetes and 87 patients without diabetes were recruited. Construct validity was confirmed by assessing the correlation with previously established measures. Confirmatory factor analysis showed the KISS to have good model fitness (adjusted goodness‐of‐fit index = 0.856). Test–retest reproducibility analysis showed that the intraclass coefficient of the first and a second KISS was 0.843 (P

ABSTRACT 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

Abstract Aims/Introduction Many East Asians with type 2 diabetes are elderly and have a low body mass index (BMI), especially in 'super‐aged' populations, such as Japan. This post‐hoc analysis assessed once‐weekly semaglutide efficacy and safety in Japanese individuals with type 2 diabetes across baseline age and BMI subgroups. Materials and Methods Data were derived from the Semaglutide Unabated Sustainability in Treatment of Type 2 Diabetes (SUSTAIN) Japan monotherapy and SUSTAIN Japan oral antidiabetes drug (OAD) combination trials comparing once‐weekly semaglutide with sitagliptin or OADs, respectively. Participants were grouped by baseline age (

ABSTRACT Aims/Introduction We investigated the utilization of healthcare resources in patients with type 2 diabetes treated with empagliflozin, a sodium‐glucose co‐transporter‐2 (SGLT2) inhibitor, versus dipeptidyl peptidase‐4 (DPP‐4) inhibitors in clinical practice in Japan, South Korea, and Taiwan. Materials and Methods We analyzed the Japanese Medical Data Vision database (December 2014–April 2018), the South Korean National Health Information Database, and the Taiwanese National Health Insurance claims database (both May 2016–December 2017). Patients with type 2 diabetes starting empagliflozin, 10 or 25 mg, or a DPP‐4 inhibitor were matched 1:1 via propensity scores (PS). We compared inpatient care needs, emergency room (ER) visits, and outpatient visits between the treatment groups using Poisson regression and Cox proportional hazards models, pooled across countries by random‐effects meta‐analysis. Results We identified 28,712 pairs of PS‐matched patients; the mean follow‐up was 5.7–6.8 months. Empagliflozin‐treated patients had a 27% lower risk of all‐cause hospitalization compared with DPP‐4 inhibitor–treated patients (rate ratio [RR] 0.73, 95% CI 0.67–0.79), and 23% reduced risk for first hospitalization (hazard ratio 0.77, 95% CI 0.73–0.81). The risk for an ER visit was 12% lower with empagliflozin than with DPP‐4 inhibitors (RR 0.88, 95% CI 0.83–0.94) while the risk for outpatient visit was 4% lower (RR 0.96, 95% CI 0.96–0.97). These findings were generally consistent across countries, regardless of baseline cardiovascular disease, and in the subgroup starting empagliflozin with the 10 mg dose. Conclusions Empagliflozin treatment was associated with lower inpatient care needs and other healthcare resource utilization than DPP‐4 inhibitors in routine clinical practice in East Asia in this study.

Abstract Aims/Introduction This 6‐month, single‐center, prospective, open‐labeled, randomized trial was designed to investigate whether physicians’ diabetes self‐management education using an education tool developed by the Japan Association of Diabetes Education and Care and a self‐monitoring of blood glucose (SMBG) analyzer improves glycemic control in individuals with type 2 diabetes receiving insulin and SMBG. Materials and Methods Participants were randomized into intervention (I) and control (C) groups. Both groups received physicians’ diabetes self‐management education at each hospital visit, whereas the Japan Association of Diabetes Education and Care education tool and the SMBG readings analyzer was used in group I, but not group C. All participants filled out a diabetes treatment‐related quality of life form and an original questionnaire on SMBG use with five questions (Q1–Q5) before and after the study period. Results A total of 76 individuals were recruited and randomized. Glycated hemoglobin (HbA1c) was significantly improved during the study period in group I, whereas no significant change was observed in group C. The change in HbA1c was greater in group I, although it did not reach statistical significance. The diabetes treatment‐related quality of life total score was not changed in either group. Interestingly, the score of Q1 (“How important is SMBG to you?”) in the SMBG questionnaire was unchanged in group I, whereas it was significantly decreased in group C. HbA1c change was independently associated with changes in insulin dose and SMBG Q1 score. Conclusion Greater HbA1c‐lowering by physicians’ diabetes self‐management education using the Japan Association of Diabetes Education and Care education tool and SMBG analyzer in individuals with type 2 diabetes receiving insulin and SMBG was suggested, but not confirmed.

Abstract Aims/Introduction Differences in the glucose‐lowering mechanisms of glucagon‐like peptide‐1 receptor agonists (GLP‐1RAs) have been noted. Clarifying these differences could facilitate the choice of optimal drugs for individuals with type 2 diabetes and requires investigation in a clinical setting. Materials and Methods A single‐arm, prospective, observational study was conducted to evaluate the effects of various GLP‐1RAs on postprandial glucose excursion, secretions of insulin and glucagon as well as on the gastric emptying rate. Participants were subjected to meal tolerance tests before and 2 weeks and 12 weeks after GLP‐1RA initiation. Effects on postprandial secretions of glucose‐dependent insulinotropic polypeptide (GIP) and apolipoprotein B48 were also investigated. Results Eighteen subjects with type 2 diabetes received one of three GLP‐1RAs, i.e., lixisenatide, n = 7; liraglutide, n = 6; or dulaglutide, n = 5. While 12‐week administration of all of the GLP‐1RAs significantly reduced HbA1c, only lixisenatide and liraglutide, but not dulaglutide, significantly reduced body weight. Postprandial glucose elevation was improved by all of the GLP‐1RAs. Postprandial insulin levels were suppressed by lixisenatide, while insulin levels were enhanced by liraglutide. Postprandial glucagon levels were suppressed by lixisenatide. The gastric emptying rate was significantly delayed by lixisenatide, while liraglutide and dulaglutide had limited effects on gastric emptying. GIP secretion was suppressed by lixisenatide and liraglutide. Apolipoprotein B48 secretion was suppressed by all of the GLP‐1RAs. Conclusions All of the GLP‐1RAs were found to improve HbA1c in a 12‐week prospective observational study in Japanese individuals with type 2 diabetes. However, differences in the mechanisms of the glucose‐lowering effects and body weight reduction were observed.

ABSTRACT Heterozygous RFX6 mutation has emerged as a potential cause of maturity‐onset diabetes mellitus of the young (MODY). A 16‐year‐old female was diagnosed with diabetes by her family doctor and was referred to our institution for genetic examination. Genetic testing revealed a novel RFX6 heterozygous mutation (NM_173560: exon17: c.1954C>T: p.R652X) in the patient and in her mother and brother. She had no islet‐specific autoantibodies and showed a reduced meal‐induced response of insulin, glucose‐dependent insulinotropic polypeptide, and glucagon‐like peptide‐1, which is consistent with the phenotype of MODY due to heterozygous RFX6 mutation. In conclusion, we report a case of MODY due to a novel heterozygous mutation, p.R652X.

Fasting with varying intensities is used to treat obesity-related diseases. Re-feeding after fasting exhibits hyperphagia and often rebound weight gain. However, the mechanisms underlying the hyperphagia and rebound remain elusive. Here we show that 24 h food restriction (24 h FR) and milder 50% FR, both depress synaptic transmission in the hypothalamic paraventricular nucleus (PVN) and induce acute hyperphagia in rats. 24 h FR is followed by weight rebound but 50% FR is not. Orexigenic neuropeptide Y (NPY) via the Y1 receptor (Y1R) inhibited the miniature excitatory postsynaptic current (mEPSC) on anorexigenic oxytocin neurons in the PVN. 24 h FR and 50% FR activated this neuronal pathway to induce acute hyperphagia on Days 1–3 and Days 1–2 after FR, respectively. 24 h FR induced large mEPSC depression, recurrent hyperphagia on Days 9–12 and rebound weight gain on Days 12–17, whereas 50% FR induced moderate mEPSC depression and sustained weight reduction. Transverse data analysis on Day 1 after 24 h FR and 50% FR demonstrated saturation kinetics for the mEPSC depression-hyperphagiacurve, implying hysteresis. The results reveal FR-driven synaptic plasticity in the NPY-Y1R-oxytocin neurocircuit that drives acute hyperphagia. FR with the intensity that regulates the synapse-feeding relay without hysteresis is the key for successful dieting.

Abstract To clarify the association between lifestyle changes as a result of coronavirus disease 2019 containment measures and changes in metabolic and glycemic status in patients with diabetes, a cross‐sectional, single‐center, observation study was carried out. A self‐reported questionnaire was provided to ascertain the frequency of various lifestyle activities before and after the coronavirus disease 2019 containment measures in Japan. Among 463 patients, change in glycated hemoglobin was significantly associated with change in bodyweight. After stratification by age 65 years, binary logistic regression analysis showed that increased frequency of snack eating increased bodyweight (odds ratio 1.709, P = 0.007) and glycated hemoglobin (odds ratio 1.420, P = 0.025) in the younger group, whereas in the older patients, reduced walking activities resulted in weight gain (odds ratio 0.726, P = 0.010). In conclusion, changes in eating behavior and physical activity increased bodyweight and reduced glycemic control among diabetes patients, but by different processes depending on age under the coronavirus disease 2019 containment measures in Japan.

Abstract Aims/Introduction Glutamine is the most abundant amino acid in the circulation. In this study, we investigated cell signaling in the amplification of insulin secretion by glutamine. Materials and Methods Clonal pancreatic β‐cells MIN6‐K8, wild‐type B6 mouse islets, glutamate dehydrogenase (GDH) knockout clonal β‐cells (Glud1KOβCL), and glutamate‐oxaloacetate transaminase 1 (GOT1) knockout clonal β‐cells (Got1KOβCL) were studied. Insulin secretion from these cells and islets was examined under various conditions, and intracellular glutamine metabolism was assessed by metabolic flux analysis. Intracellular Ca2+ concentration ([Ca2+]i) was also measured. Results Glutamine dose‐dependently amplified insulin secretion in the presence of high glucose in both MIN6‐K8 cells and Glud1KOβCL. Inhibition of glutaminases, the enzymes that convert glutamine to glutamate, dramatically reduced the glutamine‐amplifying effect on insulin secretion. A substantial amount of glutamate was produced from glutamine through direct conversion by glutaminases. Glutamine also increased [Ca2+]i at high glucose, which was abolished by inhibition of glutaminases. Glutamic acid dimethylester (dm‐Glu), a membrane permeable glutamate precursor that is converted to glutamate in cells, increased [Ca2+]i as well as induced insulin secretion at high glucose. These effects of glutamine and dm‐Glu were dependent on calcium influx. Glutamine also induced insulin secretion in clonal β‐cells MIN6‐m14, which otherwise exhibit no insulin secretory response to glucose. Conclusions Glutamate converted from glutamine is an essential mediator that enhances calcium signaling in the glutamine‐amplifying effect on insulin secretion. Our data also suggest that glutamine exerts a permissive effect on glucose‐induced insulin secretion.

Maturity-onset diabetes of the young (MODY) is a form of monogenic diabetes mellitus characterised by early onset and dominant inheritance. Delayed diagnosis or misdiagnosis as type 1 or type 2 diabetes mellitus is common. Definitive genetic diagnosis is essential for appropriate treatment of patients with MODY. The hepatocyte nuclear factor 1-beta (HNF1B) gene is responsible for MODY type 5 (MODY5), which has distinctive clinical features including renal disease. MODY5 should always be considered by clinicians in patients with early onset diabetes and renal anomalies. We report a case of a 30-year-old Japanese male with early-onset diabetes mellitus, renal anomalies and family history of diabetes that was suggestive of MODY5. Renal histology showed no evidence of diabetic nephropathy. Genetic testing revealed a novel heterozygous splice-site mutation of the HNF1B gene in the family members. It was strongly suggested that the mutation could underlie our patient’s MODY5.

Unimolecular peptide‐based dual agonists against glucagon‐like peptide‐1 receptor (GLP‐1R) and glucose‐dependent insulinotropic polypeptide receptor (GIPR) have been gaining much attention recently as novel antidiabetic agents that can potentially control glycemia and bodyweight. Although GLP‐1 and GIP both enhance insulin secretion and subsequently ameliorate postprandial glucose excursion, most research has focused on GLP‐1R as a therapeutic target for type 2 diabetes. This is partly because the effects of GIPR activation on glycemia and bodyweight have been controversial. GIPR‐deficient mice showed impaired glucose tolerance with reduced β‐cell function and resistance to high‐fat diet‐induced obesity, whereas GIPR agonists improved glycemia and prevented high‐fat diet‐induced obesity in mice. Conflicting results in mice might be explained by pharmacological levels of GIP signal in the central nervous systems decreasing food intake and overcoming the obesogenic effects of GIP at physiological levels in adipose tissues. Thus, GIPR activation at pharmacological levels might result in bodyweight reduction. Indeed, bodyweight reduction by GIPR/GLP‐1R dual agonists was greater than GLP‐1R single agonists in individuals with type 2 diabetes. Thus, GLP‐1R/GIPR dual agonists can add additional therapeutic efficacy to tailored diabetes care, especially among obese individuals with type 2 diabetes. However, caution should be exercised as to whether or not these drugs are appropriate for the management of Asian type 2 diabetes patients, which are primarily characterized by non‐obesity and impaired β‐cell function, as well as in that of elderly adults with type 2 diabetes, who tend to develop sarcopenia and frailty as a result of poor energy intake.

Abstract Anti‐glutamic acid decarboxylase antibody (GADA) is an important islet cell‐associated autoantibody for the diagnosis of autoimmune type 1 diabetes mellitus. In Japan, the GADA assay kit was recently changed from radioimmunoassay (RIA) to enzyme‐linked immunosorbent assay (ELISA). Thereafter, a mismatched measurement between the two tests became apparent in clinical situations. The present study aimed to clarify the actual extent of mismatch between the two measurements on a larger‐scale real‐world clinical practice. In this cross‐sectional non‐local/non‐hospital‐based study, we collected anonymized data on GADA levels of 598 participants, who were simultaneously measured with GADA‐RIA and GADA enzyme‐linked immunosorbent assay tests. We found that 34% of the GADA‐RIA‐positive participants showed negative results in the GADA enzyme‐linked immunosorbent assay test; the mismatch was predominantly observed in participants with relatively low GADA‐RIA levels (

Abstract Aims/Introduction We investigated the safety and tolerability of empagliflozin (EMPA) in East Asian patients with type 2 diabetes. Materials and Methods Data were pooled from participants with type 2 diabetes evenly randomized to a placebo, EMPA 10 mg or EMPA 25 mg in 15 phase I–III trials. Adverse events (AEs) were analyzed in the subgroup of trial participants from East Asian countries/regions. Results In total, 709, 724 and 708 East Asian trial participants with type 2 diabetes received a placebo, EMPA 10 mg and EMPA 25 mg, respectively; total exposure was 953, 1,072, and 1,033 patient‐years in these groups, respectively. The EMPA and placebo groups had similar incidences of severe AEs, serious AEs and AEs leading to discontinuation. Incidences of hypoglycemia differed according to anti‐diabetes medication used at baseline. Higher rates of events consistent with genital infection were observed with EMPA (EMPA 1.5–1.7/100, placebo 0.2/100 patient‐years). Rates of AEs consistent with volume depletion were comparable among treatment groups (0.8–1.4/100 patient‐years), but in trial participants aged ≥65 years, the rate was greater with EMPA 25 mg (EMPA 25 mg 3.5/100, placebo 2.0/100 patient‐years). Incidences of events consistent with urinary tract infection, thromboembolic events, renal events, hepatic AEs, diabetic ketoacidosis, fractures and lower limb amputation were similar between EMPA and the placebo. Conclusions In the present pooled analysis, EMPA was well tolerated in East Asian type 2 diabetes patients based on >2,100 patient‐years’ exposure, consistent with results from the overall analysis population.

Abstract Aims/Introduction It is reported that interfering substances in the blood might influence the value for measurement of active glucagon‐like peptide‐1 (GLP‐1) in human plasma. Solid phase extraction (SPE) pretreatment is recommended to reduce their influence, but it requires a lot of cost and time. However, there is little investigation about causative inhibitory substances and about methods that can replace solid phase extraction. In the present study, we aimed to seek the candidate of the substances that might interfere with an active GLP‐1 enzyme‐linked immunosorbent assay (ELISA). Materials and Methods Two kinds of active GLP‐1 ELISA kits using different antibodies, plural extraction carriers and elution solutions were used to evaluate the SPE method. Active GLP‐1 concentration was compared with or without SPE, and with or without a heterophilic blocking tube. Results Active GLP‐1 values were often higher without SPE compared with those with SPE pretreatment. This difference was eliminated by pretreatment with a heterophilic blocking tube or ELISA kits that did not use a mouse monoclonal antibody, and was independent of SPE. Conclusions Substances absorbed to a heterophilic blocking tube carrier might interfere with an active GLP‐1 immunoassay. Solid‐phase extraction treatment is required for measurement of active GLP‐1 by an ELISA kit affected by heterophilic antibodies.

A key factor for the insulin response to oral glucose is the pro-glucagon derived incretin hormone glucagon-like peptide-1 (GLP-1), together with the companion incretin hormone, glucose-dependent insulinotropic polypeptide (GIP). Studies in GIP and GLP-1 receptor knockout (KO) mice have been undertaken in several studies to examine this role of the incretin hormones. In the present study, we reviewed the literature on glucose and insulin responses to oral glucose in these mice. We found six publications with such studies reporting results of thirteen separate study arms. The results were not straightforward, since glucose intolerance in GIP or GLP-1 receptor KO mice were reported only in eight of the arms, whereas normal glucose tolerance was reported in five arms. A general potential weakness of the published study is that each of them have examined effects of only one single dose of glucose. In a previous study in mice with genetic deletion of both GLP-1 and GIP receptors we showed that these mice have impaired insulin response to oral glucose after large but not small glucose loads, suggesting that the relevance of the incretin hormones may be dependent on the glucose load. To further test this hypothesis, we have now performed a stepwise glucose administration through a gastric tube (from zero to 125mg) in model experiments in anesthetized female wildtype, GLP-1 receptor KO and GIP receptor KO mice. We show that GIP receptor KO mice exhibit glucose intolerance in the presence of impaired insulin response after 100 and 125 mg glucose, but not after lower doses of glucose. In contrast, GLP-1 receptor KO mice have normal glucose tolerance after all glucose loads, in the presence of a compensatory increase in the insulin response. Therefore, based on these results and the literature survey, we suggest that GIP and GLP-1 receptor KO mice retain normal glucose tolerance after oral glucose, except after large glucose loads in GIP receptor KO mice, and we also show an adaptive mechanism in GLP-1 receptor KO mice, which needs to be further examined.

Introduction Elderly people (≥65 years) with type 2 diabetes mellitus (T2DM) are becoming increasingly prevalent, notably in Japan. As cardiovascular (CV) risk increases with age and sodium–glucose cotransporter-2 (SGLT2) inhibitors reduce CV risk, elderly patients with T2DM are increasingly likely to be prescribed these glucose-lowering drugs. There is controversy surrounding the effects of SGLT2 inhibitors on muscle mass, particularly in elderly patients for whom loss of muscle is especially undesirable; however, robust evidence on this important issue is lacking. Consequently, we have designed a clinical trial of the SGLT2 inhibitor empagliflozin in elderly Japanese patients with T2DM (Empagliflozin in Elderly T2DM Patients (EMPA-ELDERLY)) to assess its effects on body composition as well as glycaemic control. EMPA-ELDERLY will be the first randomised clinical trial of an SGLT2 inhibitor in elderly patients with T2DM to evaluate effects on skeletal muscle mass, muscle strength and physical performance concurrently.Methods and analysis EMPA-ELDERLY is a randomised, double-blind, placebo-controlled, parallel-group clinical trial to be conducted in Japan. Patients with T2DM aged ≥65 years are eligible if they are Japanese with a body mass index of ≥22 kg/m2 and glycated haemoglobin (HbA1c) levels from ≥7.0% to ≤10.0% from either diet and exercise alone or treatment with oral glucose-lowering drugs. Approximately 128 participants will be randomised 1:1 to once per day, oral, double-blind treatment with empagliflozin 10 mg or matching placebo for 52 weeks. The primary endpoint is the change in HbA1c level from baseline at week 52. Secondary endpoints include changes from baseline to 52 weeks in body composition, including muscle mass and body fat, measured by bioelectrical impedance analysis, as well as skeletal muscle index, grip strength and time in the five-time chair stand test. Other endpoints include changes in patient-reported outcomes (including quality of life), cognitive function and safety.Ethics and dissemination We will submit the trial results to conferences and peer-reviewed journals.Trial registration number NCT04531462.

Abstract Aim To evaluate the effectiveness of empagliflozin in clinical practice in East Asia in the Empagliflozin Comparative Effectiveness and Safety (EMPRISE) East Asia study. Materials and methods Data were obtained from the Medical Data Vision database (Japan), National Health Insurance Service database (South Korea) and National Health Insurance database (Taiwan). Patients aged ≥ 18 years with type 2 diabetes initiating empagliflozin or a dipeptidyl peptidase‐4 (DPP‐4) inhibitor were 1:1 propensity score (PS) matched into sequentially built cohorts of new users naïve to both drug classes. This design reduces confounding due to switching treatments, time lag and immortal time biases. Outcomes included hospitalization for heart failure (HHF), end‐stage renal disease (ESRD) and all‐cause mortality. Hazard ratios (HRs) and 95% CIs were estimated using Cox proportional models, controlling for > 130 baseline characteristics in each data source and pooled by random‐effects meta‐analysis. Results Overall, 28 712 pairs of PS‐matched patients were identified with mean follow‐up of 5.7‐6.8 months. Compared with DPP‐4 inhibitors, the risk of HHF was reduced by 18% and all‐cause mortality was reduced by 36% with empagliflozin (HR 0.82; 95% CI 0.71‐0.94, and HR 0.64; 95% CI 0.50‐0.81, respectively). Reductions were consistent across countries, and in patients with and without baseline cardiovascular disease. ESRD was also significantly reduced with empagliflozin versus DPP‐4 inhibitors (HR 0.37; 95% CI 0.24‐0.58). Conclusions Empagliflozin treatment was associated with reduced risk for HHF, all‐cause mortality and ESRD compared with DPP‐4 inhibitors in routine clinical practice in Japan, South Korea and Taiwan.

Introduction To investigate factors affecting glycemic control, oral antidiabetic drug (OAD) treatment distribution and self-care activities among patients with type 2 diabetes mellitus (T2DM) who newly initiate OAD monotherapy in a real-world setting in Japan.Research design and methods A Real-world Observational Study on Patient Outcomes in Diabetes (RESPOND) is an ongoing, prospective, observational cohort study with follow-up at 6, 12, 18 and 24 months. Primary objectives include OAD treatment patterns (cross-sectional and longitudinal) among diabetes specialists versus non-specialists; adherence to diabetes self-care activities; quality of life; treatment satisfaction among patients and target attainment rates of parameters, including glycated hemoglobin. Here, we present the study design and baseline data.Results Of 1506 patients enrolled (June 2016–May 2017; 174 sites in Japan), 1485 were included in the baseline analysis (617 treated by specialists, 868 by non-specialists). Most patients were prescribed dipeptidyl peptidase-4 inhibitors (DPP-4Is) (specialist vs non-specialist, 54.1% vs 57.1%), then sodium-glucose cotransporter 2 inhibitors (13.9% vs 22.2%), metformin (20.3% vs 12.9%) and other OADs (

Appetite loss or anorexia substantially deteriorates quality of life in various diseases, and stand upstream of frailty. Neuropeptide Y (NPY) in the hypothalamic arcuate nucleus (ARC) and ghrelin released from stomach are potent inducers of appetite. We previously reported that Ninjin'yoeito, a Japanese kampo medicine comprising twelve herbs, restores food intake, and body weight in cisplatin-treated anorectic mice. Furthermore, Ninjin'yoeito increased cytosolic Ca2+ concentration ([Ca2+]i) in not only ghrelin-responsive but ghrelin-unresponsive NPY neurons in ARC. The cellular lineage/differentiation of ghrelin-unresponsive neuron is less defined but might alter along with aging and diet. This study examined the occupancy of ghrelin-unresponsive neurons among ARC NPY neurons in adult mice fed normal chow, and explored the mechanisms underlying Ninjin'yoeito-induced [Ca2+]i increases in ghrelin-unresponsive vs. ghrelin-responsive NPY neurons. Single ARC neurons were subjected to [Ca2+]i measurement and subsequent immunostaining for NPY. Ghrelin failed to increase [Ca2+]i in 42% of ARC NPY neurons. Ninjin'yoeito (10 μg/ml)-induced increases in [Ca2+]i were abolished in Ca2+ free condition in ghrelin-responsive and ghrelin-unresponsive ARC NPY neurons. Ninjin'yoeito-induced [Ca2+]i increases were inhibited by N-type Ca2+ channel blocker ω-conotoxin in the majority (17 of 20), while by L-type Ca2+ channel blocker nitrendipine in the minority (2 of 23), of ghrelin-responsive neurons. In contrast, Ninjin'yoeito-induced [Ca2+]i increases were inhibited by nitrendipine in the majority (14 of 17), while by ω-conotoxin in the minority (8 of 24), of ghrelin-unresponsive neurons. These results indicate that ghrelin-unresponsive neurons occur substantially among NPY neurons of ARC in adult mice fed normal chow. Ninjin'yoeito preferentially target N-type and L-type Ca2+ channels in the majority of ghrelin-responsive and ghrelin-unresponsive neurons, respectively, to increase [Ca2+]i. We suggest ARC N- and L-type Ca2+ channels as potential targets for activating, respectively, ghrelin-responsive, and unresponsive NPY neurons to treat anorexia.

Glucose-dependent insulinotropic polypeptide (GIP) has been reported to have an atheroprotective property in animal models. However, the effect of GIP on macrophage foam cell formation, a crucial step of atherosclerosis, remains largely unknown. We investigated the effects of GIP on foam cell formation of, and CD36 expression in, macrophages extracted from GIP receptor-deficient (Gipr−/−) and Gipr+/+ mice and cultured human U937 macrophages by using an agonist for GIP receptor, [D-Ala2]GIP(1–42). Foam cell formation evaluated by esterification of free cholesterol to cholesteryl ester and CD36 gene expression in macrophages isolated from Gipr+/+ mice infused subcutaneously with [D-Ala2]GIP(1–42) were significantly suppressed compared with vehicle-treated mice, while these beneficial effects were not observed in macrophages isolated from Gipr−/− mice infused with [D-Ala2]GIP(1–42). When macrophages were isolated from Gipr+/+ and Gipr−/− mice, and then exposed to [D-Ala2]GIP(1–42), similar results were obtained. [D-Ala2]GIP(1–42) attenuated ox-LDL uptake of, and CD36 gene expression in, human U937 macrophages as well. Gene expression level of cyclin-dependent kinase 5 (Cdk5) was also suppressed by [D-Ala2]GIP(1–42) in U937 cells, which was corelated with that of CD36. A selective inhibitor of Cdk5, (R)-DRF053 mimicked the effects of [D-Ala2]GIP(1–42) in U937 cells. The present study suggests that GIP could inhibit foam cell formation of macrophages by suppressing the Cdk5-CD36 pathway via GIP receptor.

Type 2 diabetes mellitus (T2D) is one of the most serious global health problems. This is partly a result of its drastic increase in East Asia, which now comprises more than a quarter of the global diabetes population. Ethnicity and lifestyle factors are two determinants in the aetiology of T2D, and changes such as increased animal fat intake and decreased physical activity link readily to T2D in East Asians, which is characterised primarily by β-cell dysfunction that is evident immediately after ingestion of glucose or a meal, and less adiposity compared with T2D in Caucasians. These pathophysiological differences have an important impact on therapeutic approaches. Incretin-based therapies, such as dipeptidyl peptidase-4 inhibitors (DPP-4i) and glucagon-like peptide-1 receptor agonists (GLP-1RA), have become widely available for the management of T2D. Incretins, glucose-dependent insulinotropic polypeptide, and glucagon-like peptide-1 are secreted from the gut in response to the ingestion of various nutrients, including carbohydrates, proteins, and fats, and enhance insulin secretion via a glucose-dependent pathway to exert their glucose-lowering effects. Recent meta-analyses of clinical trials of DPP-4i and GLP-1RA found the drugs to be more effective in East Asians, most likely due to amelioration of the primary β-cell dysfunction by increased stimulation through incretin activity. In addition, our finding that the glycosylated haemoglobin-lowering effects of DPP-4i are enhanced by fish intake, and possibly worsened by animal fat intake, suggests that dietary habits such as eating more fish and less meat can affect the secretion of incretins, and supports the greater efficacy of incretin-based therapies in East Asians.

Objective. To investigate the characteristics of isolated impaired glucose tolerance (IGT) and isolated impaired fasting glucose (IFG), we analyzed the factors responsible for elevation of 2-hour postchallenge plasma glucose (2 h PG) and fasting plasma glucose (FPG) levels. Methods. We investigated the relationship between 2 h PG and FPG levels who underwent 75 g OGTT in 5620 Japanese subjects at initial examination for medical check-up. We compared clinical characteristics between isolated IGT and isolated IFG and analyzed the relationships of 2 h PG and FPG with clinical characteristics, the indices of insulin secretory capacity, and insulin sensitivity. Results. In a comparison between isolated IGT and isolated IFG, insulinogenic index was lower in isolated IGT than that of isolated IFG (0.43 ± 0.34 versus 0.50 ± 0.47, resp.; p

Incretin-based therapies have been gaining much attention recently as a new class of therapeutics for type 2 diabetes worldwide. Among them, glucagon-like peptide-1 receptor agonist liraglutide has been rapidly increasing its global usage. Once daily injection of liraglutide significantly ameliorates glycemic control in patients with type 2 diabetes by enhancing insulin secretion and suppressing glucagon secretion glucose-dependently. Liraglutide delays gastric emptying and suppresses food intakes, both of which contribute to glucose lowering and weight reduction. Efficacy and safety of liraglutide in management of type 2 diabetes have been well documented in several key clinical trials such as series of phase 3 Liraglutide Effect and Action in Diabetes (LEAD) trials, and the liraglutide -versus- sitagliptin trial. Recent two trials dealing with monotherapy and sulfonylurea combination therapy on Japanese patients with type 2 diabetes furthermore indicate liraglutide's effectiveness in non-obese diabetes. In this review, we summarize results from such clinical trials, and discuss efficacy and safety of liraglutide in management of type 2 diabetes in various countries, along with a pitfall of liraglutide usage in real clinical setting.

AIMS:The gastrointestinal hormone GIP promotes pancreatic islet function and exerts pro-survival actions on cultured beta-cells. However, GIP also promotes lipogenesis, thus potentially restricting its therapeutic use. The current studies evaluated the effects of a truncated GIP analog, D-Ala(2)-GIP(1-30) (D-GIP(1-30)), on glucose homeostasis and beta-cell mass in rat models of diabetes. MATERIALS AND METHODS:The insulinotropic and pro-survival potency of D-GIP(1-30) was evaluated in perfused pancreas preparations and cultured INS-1 beta-cells, respectively, and receptor selectivity evaluated using wild type and GIP receptor knockout mice. Effects of D-GIP(1-30) on beta-cell function and glucose homeostasis, in vivo, were determined using Lean Zucker rats, obese Vancouver diabetic fatty rats, streptozotocin treated rats, and obese Zucker diabetic fatty rats, with effects on beta-cell mass determined in histological studies of pancreatic tissue. Lipogenic effects of D-GIP(1-30) were evaluated on cultured 3T3-L1 adipocytes. RESULTS:Acutely, D-GIP(1-30) improved glucose tolerance and insulin secretion. Chronic treatment with D-GIP(1-30) reduced levels of islet pro-apoptotic proteins in Vancouver diabetic fatty rats and preserved beta-cell mass in streptozotocin treated rats and Zucker diabetic fatty rats, resulting in improved insulin responses and glycemic control in each animal model, with no change in body weight. In in vitro studies, D-GIP(1-30) exhibited equivalent potency to GIP(1-42) on beta-cell function and survival, but greatly reduced action on lipoprotein lipase activity in 3T3-L1 adipocytes. CONCLUSIONS:These findings demonstrate that truncated forms of GIP exhibit potent anti-diabetic actions, without pro-obesity effects, and that the C-terminus contributes to the lipogenic actions of GIP.