Insulin secretion capacity in the development from normal glucose tolerance to type 2 diabetes

Relationships between time in range, glycemic variability including hypoglycemia and types of diabetes therapy in Japanese patients with type 2 diabetes mellitus: Hyogo Diabetes Hypoglycemia Cognition Complications study

AIMS/INTRODUCTION

Continuous glucose monitoring (CGM) metrics, such as times in range (TIR) and time below range, have been shown to be useful as clinical targets that complement glycated hemoglobin (HbA1c) for patients with type 2 diabetes mellitus. We investigated the relationships between TIR, glycemic variability and patient characteristics in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

We carried out continuous glucose monitoring in 281 outpatients with type 2 diabetes mellitus who participated in a multicenter cohort (Hyogo Diabetes Hypoglycemia Cognition Complications) study.

RESULTS

The results are shown as the median (interquartile range). The age, disease duration and HbA1c were 68 years (62-71 years), 13 years (7-23 years) and 6.9% (6.5-7.5%), respectively. TIR and standard deviation obtained by continuous glucose monitoring worsened significantly with increasing disease duration. Multiple regression analyses showed that disease duration (standard partial regression coefficient, β = -0.160, P = 0.003), diabetic peripheral neuropathy (β = -0.106, P = 0.033) and urinary albumin excretion (β = -0.100, P = 0.043) were useful explanatory factors for TIR. In contrast, HbA1c (β = -0.398, P < 0.001) and the use of antidiabetic drugs potentially associated with severe hypoglycemia (β = 0.180, P = 0.028), such as sulfonylureas, glinides and insulin, were useful explanatory factors for time below range in the elderly patients with type 2 diabetes mellitus.

CONCLUSIONS

The results of this study suggest that disease duration and diabetic complications are associated with TIR deterioration. In addition, low HbA1c levels and the use of antidiabetic drugs potentially associated with severe hypoglycemia might worsen the time below range in the elderly.

Clinical profiles of hyperglycemic crises: A single-center retrospective study from Japan

AIMS/INTRODUCTION

The aim of the present study was to clarify the pathophysiologies of hyperglycemic crises in Japanese patients.

MATERIALS AND METHODS

This was a retrospective study of patients with hyperglycemic crises admitted to Kumamoto Medical Center, Kumamoto, Japan, between 2012 and 2019. Patients were classified as having diabetic ketoacidosis (DKA), hyperglycemic hyperosmotic syndrome (HHS) or a mixed state of the two conditions (MIX), and laboratory data and levels of consciousness at hospital admission, as well as the rates of mortality and coagulation disorders, were compared.

RESULTS

The diagnostic criteria for hyperglycemic crisis were met in 144 cases, comprising 87 (60.4%), 38 (26.4%) and 19 (13.2%) cases of DKA, HHS and MIX, respectively. Type 1 diabetes was noted in 46.0 and 26.3% of patients in the DKA and MIX groups, respectively. Fibrin degradation product and D-dimer levels were significantly higher in the HHS group than in the DKA group (DKA and HHS groups: fibrin degradation product 7.94 ± 8.43 and 35.54 ± 51.80 μg/mL, respectively, P < 0.01; D-dimer 2.830 ± 2.745 and 14.846 ± 21.430 μg/mL, respectively, P < 0.01). Mortality rates were 5.7, 13.2 and 5.3% in the DKA, HHS and MIX groups, respectively. Seven patients (4.9%), four of whom were in the MIX group, had acute arterial occlusive diseases.

CONCLUSIONS

The low frequency of type 1 diabetes in DKA and MIX might be responsible for reduced insulin secretion in Japanese populations. Patients with hyperglycemic crises have increased coagulability, and acute arterial occlusion needs to be considered, particularly in MIX.

Missense Variants in PAX4 Are Associated with Early-Onset Diabetes in Chinese

INTRODUCTION

East Asians are more susceptible to early-onset diabetes than Europeans and exhibit reduced insulin secretion at earlier stages. PAX4 plays a critical role in the development of β-cells. The dysfunction-missense variants PAX4 R192H and PAX4 R192S are common in East Asians but rare in Europeans. Therefore, we aim to investigate the diabetes-associated genes, including PAX4 R192H/S, in East Asians with early-onset diabetes.

METHODS

Exome variants of 80 Chinese early-onset diabetes patients (onset age < 35 years) after the exclusion of type 1 diabetes (T1D) were detected by a customized gene panel covering 32 known diabetes-associated genes. Then, 229 subjects with early-onset diabetes (T1D excluded) and 1679 controls from the Chinese population were genotyped to validate the association of PAX4 R192H/S with early-onset diabetes and related phenotypes.

RESULTS

The gene panel detected 11 monogenic diabetes patients with five novel mutations among the 80 early-onset diabetes patients. Asian-specifically enriched PAX4 R192H and R192S were associated with early-onset diabetes (R192H: OR 1.88, 95% CI 1.37-2.60, P = 8.41 × 10^-5; R192S: OR 1.71, 95% CI 1.17-2.51, P = 0.005). In early-onset diabetes patients, PAX4 R192H carriers had higher haemoglobin A1c (HbA1c) levels (P = 0.030) and lower 2 h C-peptide levels in the oral glucose tolerance test (OGTT) (P = 0.040); R192S carriers had lower fasting C-peptide (FCP) (P = 0.011) and 2 h C-peptide levels (P = 0.033) in OGTT than non-variant carriers.

CONCLUSIONS

The ethnic-specific enrichment of PAX4 R192H/S predisposing East Asians to early-onset diabetes with decreased C-peptide levels may be one explanation of the discrepancy of diabetes between East Asians and Europeans.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT01938365).

A retrospective cohort study for the treatment of Asian diabetic ketoacidosis: optimizing initial doses of insulin

Aim

An insulin dose of 0.1 U/kg/h recommended by Western guidelines occasionally induces a precipitous decreasing blood glucose in Asian diabetic ketoacidosis (DKA). It is known that clinical factors, such as insulin sensitivity, differ between Asians and Americans/Europeans. We investigated how treatment options affect the time to DKA resolution to determine the optimal treatment for Asian DKA patients.

Methods

This was a retrospective cohort study from a single institution in Japan. A total of 34 adult DKA patients were observed. Baseline characteristics and treatment‐related parameters were compared between patients whose DKA was resolved within 18 h and those in which it was not.

Results

Significant differences were observed in the initial insulin dose (mean [standard deviation]: 0.053 [0.021] versus 0.031 [0.014] U/kg/h; P = 0.003) and the baseline β‐hydroxybutyrate (7.2 [3.2] versus 9.9 [2.6] mmol/L; P = 0.024) and HCO3− levels (11.2 [4.1] versus 7.7 [3.1] mmol/L; P = 0.014). Multivariable logistic regression analysis revealed that the initial insulin dose was significantly associated with early resolution of DKA and was independent of basal conditions. Receiver operating characteristic curve analysis indicated that the optimal cut‐off point for the initial insulin dose was 0.051 U/kg/h. With an initial insulin dose of 0.051 U/kg/h or higher, early resolution of DKA was obtained in 92.9% of patients.

Conclusion

An initial insulin dose of more than 0.05 U/kg/h provides an early resolution of DKA in Asian patients. Lower insulin doses significantly delay resolution. These results provide practical information for acute phase treatment of Asian DKA.

Glucagon-Like Peptide-1 Receptor Agonist Utilization in Type 2 Diabetes in Japan: A Retrospective Database Analysis (JDDM 57)

INTRODUCTION

There are limited real-world data on the prescribing of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a retrospective analysis of the CoDiC® database of the Japan Diabetes Clinical Data Management Study Group (JDDM). Demographic and clinical characteristics, concomitant treatment patterns, and GLP-1 RA treatment persistence or modification in patients with T2DM initiating GLP-1 RA therapy were evaluated.

RESULTS

The analysis included 932 eligible patients with T2DM who had their first GLP-1 RA prescription (index date) between September 2016 and July 2018. Mean age was 63.8 years and 56.0% were male. Most patients had an index GLP-1 RA of dulaglutide (65.7%) or liraglutide (29.1%). Common comorbidities were obesity (58.7%), hypertension (54.7%), dyslipidemia (52.0%), retinopathy (11.3%), and nephropathy (10.2%). Mean hemoglobin A1c (HbA1c) levels decreased from 8.3 to 7.8% over 6 months after GLP-1 RA initiation, and the proportion of patients achieving HbA1c < 7.0% increased from 14.4% at index date to 22.9% at 6 months. Reductions occurred in mean body weight, body mass index, triglycerides, total cholesterol, low-density lipoprotein cholesterol, and adjusted urinary albumin over 6 months. Antidiabetic medication use decreased after GLP-1 RA initiation, whereas non-antidiabetic medication prescribing showed little change. Index GLP-1 RA persistence rates were 80.5%, 66.2%, and 51.6% at 6, 12, and 18 months post-index, respectively, with a median persistence until discontinuation or switch of 600 days. Persistence rates at 6, 12, and 18 months post-index, respectively, were 81.9%, 70.7%, and 65.4% for dulaglutide and 79.7%, 60.0%, and 30.4% for liraglutide.

CONCLUSION

The study shows real-world benefits of GLP-1 RA therapy for T2DM, including improvements in HbA1c, body weight, and blood lipid profile, and supports the high rates of long-term persistence previously reported with dulaglutide, the GLP-1 RA most commonly prescribed for T2DM in Japanese clinical practice.

Changes in peripheral inflammation-related gene expression by postprandial glycemic response in healthy Japanese men

OBJECTIVES

Continuous postprandial hyperglycemia is associated with the onset of cardiovascular disease. In recent years, the mRNA expression of inflammation-related genes in peripheral blood leukocytes has been shown to be induced by an increase in blood glucose levels. The aim of this study was to investigate differences in the expression of inflammation-related genes in peripheral blood leukocytes in response to an increase in blood glucose from individuals who consumed two kinds of breakfast meals with different glycemic indexes (GIs).

METHODS

Twenty healthy Japanese men 40 to 70 y of age were given low- or high-GI meals for breakfast for 14 d. Clinical examinations were performed on days 7 and 14. Their blood glucose levels and insulin concentrations were measured from before breakfast ingestion to 120 min after. Additionally, using the blood obtained before and 120 min after breakfast, the mRNA expression levels of inflammation-related genes in peripheral leukocytes were measured.

RESULTS

The blood glucose levels were significantly lower in the low-GI meal intake group at 30, 60, and 120 min after breakfast than in the high-GI meal intake group. The intake of high-GI meals for 6 d led to an increase in the mRNA levels of interleukin-1β, S100A4, and CD18 compared with the period of low-GI meals.

CONCLUSION

The intake of a low-GI breakfast for 1 wk in healthy Japanese men resulted in lower postprandial blood glucose and insulin levels, which were accompanied by a reduced expression of inflammation-related genes in peripheral blood leukocytes.

Ethnic differences in adiposity and diabetes risk - insights from genetic studies

Type 2 diabetes is more common in non-Europeans and starts at a younger age and at lower BMI cut-offs. This review discusses the insights from genetic studies about pathophysiological mechanisms which determine risk of disease with a focus on the role of adiposity and body fat distribution in ethnic disparity in risk of type 2 diabetes. During the past decade, genome-wide association studies (GWAS) have identified more than 400 genetic variants associated with the risk of type 2 diabetes. The Eurocentric nature of these genetic studies has made them less effective in identifying mechanisms that make non-Europeans more susceptible to higher risk of disease. One possible mechanism suggested by epidemiological studies is the role of ethnic difference in body fat distribution. Using genetic variants associated with an ability to store extra fat in a safe place, which is subcutaneous adipose tissue, we discuss how different ethnic groups could be genetically less susceptible to type 2 diabetes by developing a more favourable fat distribution.

Association of Serum Calcium and Phosphate Concentrations with Glucose Metabolism Markers: The Furukawa Nutrition and Health Study

Calcium and phosphate may play an important role in cardio-metabolic abnormalities, including type 2 diabetes; however, epidemiological evidence of the association of calcium and phosphate status with glucose metabolism among Asians is limited. In the current study, we performed a cross-sectional analysis of the association of serum calcium, phosphate, and calcium–phosphate product concentrations with glucose metabolism markers among Japanese individuals. Overall, 1701 workers (aged 18–78 years) who participated in a health survey were enrolled in this study. Multivariable linear regression models were used to estimate means of homeostatic model assessment of insulin resistance (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-β), and glycated hemoglobin (HbA1c). Serum calcium concentration was positively associated with HOMA-IR and HbA1c (p for trend < 0.01). Multivariable-adjusted means (95% confidence interval (CI)) of HOMA-IR for the lowest and highest quartiles of serum calcium were 0.78 (0.75–0.82) and 1.01 (0.96–1.07), respectively. The corresponding values for HbA1c were 5.24 (5.22–5.27) and 5.29 (5.26–5.32), respectively. Serum phosphate and calcium–phosphate product concentrations were inversely associated with HOMA-IR (p for trend < 0.01). Multivariable-adjusted means (95% CI) of HOMA-IR for the lowest and highest quartiles of serum phosphate were 1.04 (0.99–1.09) and 0.72 (0.69–0.76), respectively. The corresponding values for calcium–phosphate product were 1.04 (0.99–1.09) and 0.73 (0.69–0.77), respectively. The current findings suggest that higher serum calcium and lower serum phosphate concentrations are associated with IR among apparently healthy adults.

Genetic locus responsible for diabetic phenotype in the insulin hyposecretion (ihs) mouse

Diabetic animal models have made significant contributions to understanding the etiology of diabetes and to the development of new medications. Our research group recently developed a novel diabetic mouse strain, the insulin hyposecretion (ihs)mouse. The strain involves neither obesity nor insulitis but exhibits notable pancreatic β-cell dysfunction, distinguishing it from other well-characterized animal models. In ihs mice, severe impairment of insulin secretion from pancreas has been elicited by glucose or potassium chloride stimulation. To clarify the genetic basis of impaired insulin secretion, beginning with identifying the causative gene, genetic linkage analysis was performed using [(C57BL/6 × ihs) F₁ × ihs] backcross progeny. Genetic linkage analysis and quantitative trait loci analysis for blood glucose after oral glucose loading indicated that a recessively acting locus responsible for impaired glucose tolerance was mapped to a 14.9-Mb region of chromosome 18 between D18Mit233 and D18Mit235 (the ihs locus). To confirm the gene responsible for the ihs locus, a congenic strain harboring the ihs locus on the C57BL/6 genetic background was developed. Phenotypic analysis of B6.ihs-(D18Mit233-D18Mit235) mice showed significant glucose tolerance impairment and markedly lower plasma insulin levels during an oral glucose tolerance test. Whole-genome sequencing and Sanger sequencing analyses on the ihs genome detected two ihs-specific variants changing amino acids within the ihs locus; both variants in Slc25a46 and Tcerg1 were predicted to disrupt the protein function. Based on information regarding gene functions involving diabetes mellitus and insulin secretion, reverse-transcription quantitative polymerase chain reaction analysis revealed that the relative abundance of Reep2 and Sil1 transcripts from ihs islets was significantly decreased whereas that of Syt4 transcripts were significantly increased compared with those of control C57BL/6 mice. Thus, Slc25a46, Tcerg1, Syt4, Reep2 and Sil1 are potential candidate genes for the ihs locus. This will be the focus of future studies in both mice and humans.

Pre-Exercise Glucose Ingestion May Improve Endurance Capacity in East Asian Student Athletes with Lower Blood Glucose Response

The main purpose of this study was to investigate the influence of pre-exercise glucose ingestion after a 2.5-h fast on the endurance capacity and blood glucose response in East Asian athletes who is expected to have genetically low insulin response. A total of 8 Japanese student athletes ingested 1.5 g/kg body mass of glucose (G trial) or 0.5 g/kg body mass of artificial sweetener dissolved in water (P trial) 30 min before exercise test after consuming a standardized breakfast. The exercise test comprised 40 min cycling exercise at 50% maximal oxygen uptake (VO_2max), immediately followed by cycling to exhaustion at 70% VO_2max. Before analyzing the data, we grouped the subjects into two groups depending on whether they showed rapid increase in blood glucose at the onset of exercise (increase rate in LOW group is <20% and HIGH group is ≥20%) to evaluate subject's insulin response to glucose feeding. No subjects developed rebound hypoglycemia (<70 mg/dL) in the G trial of both group. Significantly higher blood glucose during exercise was recognized only in the G trial of LOW group. Although no significant difference was observed between the two trials of both group, cycling time to exhaustion in the LOW group tended to increase because of glucose ingestion. These results suggest that pre-exercise ingestion of glucose in East Asian student athletes does not induce rebound hypoglycemia regardless of difference in individual insulin responses. Furthermore, individuals with low insulin responses seem to improve endurance performance with glucose ingestion before exercise.

Factors associated with the glucose-lowering efficacy of sitagliptin in Japanese patients with type 2 diabetes mellitus: Pooled analysis of Japanese clinical trials

AIMS/INTRODUCTION

To explore the factors associated with the glucose-lowering efficacy of sitagliptin treatment in Japanese patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

This was a post-hoc analysis of pooled data from seven sitagliptin phase II and III clinical studies carried out in Japan. All studies were double-blind, randomized, placebo-controlled, parallel-group and of 12-week duration. The analysis population consisted of 1,075 type 2 diabetes mellitus patients. In two of the trials, sitagliptin 50 mg and/or 100 mg daily were used as monotherapy; in five others, sitagliptin 50 mg daily was used as add-on treatment to ongoing pioglitazone, glimepiride, metformin, voglibose or glinides. Efficacy (reduction in hemoglobin A1c [HbA1c]) was evaluated in 12 sets of subgroups defined by demographic, glycemic, pancreatic β-cell function and insulin resistance parameters. An analysis of covariance model was used to evaluate the interaction between each parameter and efficacy.

RESULTS

Sitagliptin consistently provided a clinically meaningful reduction in HbA1c relative to placebo across all subgroups. Within subgroups, a greater absolute HbA1c reduction was associated with higher baseline HbA1c, fasting plasma glucose and 2-h post-meal glucose. Lower β-cell function, represented by homeostatic model assessment of β-cell function and insulinogenic index, was also associated with greater HbA1c reduction. In contrast, age, sex, body mass index, duration of type 2 diabetes mellitus and insulin resistance-related parameters did not interact with HbA1c changes.

CONCLUSIONS

Sitagliptin treatment was associated with clinically meaningful improvement in glycemic control in all subgroups of Japanese patients with type 2 diabetes mellitus that were evaluated. Higher baseline glycemic status and lower baseline β-cell function were identified as factors associated with greater HbA1c reduction after sitagliptin treatment.

Comparison of effectiveness and drug cost between dipeptidyl peptidase-4 inhibitor and biguanide as the first-line anti-hyperglycaemic medication among Japanese working generation with type 2 diabetes

AIMS AND OBJECTIVES

Dipeptidyl peptidase-4 inhibitor (DPP4i) is widely used for the treatment of type 2 diabetes (T2DM) in several countries such as Japan, whereas biguanide (BG; mostly metformin) is recommended as a first-line antidiabetic medication in many countries according to evidence mainly from Western countries. Although previous studies reported that DPP4i may be more efficacious for East Asians, direct comparisons of effectiveness and cost between DPP4i and BG have never been conducted in East Asia.

METHODS

We extracted claims and medical check-up data (observation period from January 2010 to March 2016) of adult patients under 70 years old with T2DM who received DPP4i or BG as first-line antidiabetic drugs. Changes in HbA1c and BMI before and 2 years after the first prescription and annual cost of antidiabetic medication during the second year were compared between the DPP4i and BG groups.

RESULTS

We extracted 1034 patients who received DPP4i and 365 patients who received BG as the first antidiabetic medication (male sex, 83.0% and 84.9%; HbA1c (mean [SD]), 7.7 [1.4]% and 7.9 [1.4]%; BMI, 26.6 [4.5] kg/m² and 28.1 [4.3] kg/m² ). After propensity score matching, changes in HbA1c and BMI were not significantly different between the groups (HbA1c, -0.67% vs -0.80% [P = .28]; BMI, -0.3 kg/m² vs -0.4 kg/m² [P = .42]). Annual cost of antidiabetic drugs was significantly higher in the DPP4i group (US $458.7 vs 273.3 [P < .001]). Many patients continued each medication at the follow-up visit (78.3% of the DPP4i group and 73.7% of the BG groups).

CONCLUSIONS

The first antidiabetic prescription for the patient was mostly continued thereafter. BG may be recommendable as the first-line medication for patients with T2DM, especially for middle-aged, male population with greater BMI. It is worth addressing the discrepancy between practice in Japan and that recommended in international guidelines.

Higher circulating orosomucoid and lower early-phase insulin secretion in midlife Japanese with slower glucose disposal during oral glucose tolerance tests

Objective

We examined whether serum orosomucoid, an acute phase protein as with C-reactive protein, in addition to insulin resistance and beta-cell dysfunction, was involved in glucose disposal during oral glucose tolerance tests.

Research design and methods

124 midlife Japanese (65 women, 66% with normal glucose tolerance) received dual-energy X-ray absorptiometry and 75 g oral glucose tolerance tests with multiple postload glucose and insulin measurements. Subjects were divided based on the relationship between postload and fasting glucose. Obesity measures, insulin resistance, insulin secretion, serum orosomucoid and adiponectin were cross-sectionally analyzed by analysis of variance and then Bonferroni's multiple comparison procedure.

Results

In 10 subjects (group A) and 19 subjects (group B), postload glucose fell below fasting glucose at 1 h and 2 h, respectively. In the remaining 95 subjects (group C), postload glucose never fell below fasting glucose. The insulinogenic index was lower and area under the glucose curve was higher in groups B and C as compared to group A (both p<0.05), whereas the Matsuda index, the homeostasis model assessment of insulin resistance, adipose insulin resistance (the product of fasting free fatty acid and insulin) and area under the insulin curve did not differ. Although there was no difference in fat mass index, trunk/leg fat ratio and adiponectin, orosomucoid was higher in group C as compared to group A (p<0.05).

Conclusions

Lower early-phase insulin secretion and low-grade inflammation were associated with slower glucose disposal during an oral glucose tolerance test in midlife Japanese. The rate of glucose disposal was not related to adiposity and insulin resistance.

A Low-Carbohydrate Diet Improves Glucose Metabolism in Lean Insulinopenic Akita Mice Along With Sodium-Glucose Cotransporter 2 Inhibitor

OBJECTIVE

A low-carbohydrate diet (LC) can be beneficial to obese subjects with type2 diabetes mellitus (T2DM). Sodium-glucose cotransporter 2 inhibitor (SGLT2i) presents prompt glucose-lowering effects in subjects with T2DM. We investigated how LC and SGLT2i could similarly or differently influence on the metabolic changes, including glucose, lipid, and ketone metabolism in lean insulinopenic Akita mice. We also examined the impacts of the combination.

METHODS

Male Akita mice were fed ad libitum normal-carbohydrate diet (NC) as a control or low-carbohydrate diet (LC) as an intervention for 8 weeks with or without SGLT2i treatment. Body weight and casual bold glucose levels were monitored during the study, in addition to measuring TG, NEFA, and ketone levels. We quantified gene expressions involved in gluconeogenesis, lipid metabolism and ketogenesis in the liver and the kidney. We also investigated the immunostaining analysis of pancreatic islets to assess the effect of islet protection.

RESULTS

Both LC and SGLT2i treatment reduced chronic hyperglycemia. Moreover, the combination therapy additionally ameliorated glycemic levels and preserved the islet morphology in part. LC but not SGLT2i increased body weight accompanied by epididymal fat accumulation. In contrast, SGLT2i, not LC potentiated four-fold ketone production with higher ketogenic gene expression, in comparison with the non-treated Akita mice. Besides, the combination did not enhance further ketone production compared to the SGLT2i alone.

CONCLUSIONS

Our results indicated that both LC and SGLT2i reduced chronic hyperglycemia, and the combination presented synergistic favorable effects concomitantly with amelioration of islet morphology, while the combination did not enhance further ketosis in Akita mice.

Combination use of liraglutide and insulin to Japanese patients with multiple insulin injection: efficacy and cost

OBJECTIVES

The introduction of liraglutide in the treatment of patients with type 2 diabetes already taking insulin is still subject to discussion in terms of timing and benefits. Gradually intensive insulin therapy is hastily prescribed. Switching from multiple insulin injection (MII) to insulin and liraglutide is evaluated in this study.

METHODOLOGY

We studied 92 patients with type 2 diabetes previously under MII, C-peptide ≥ 1.5 ng/ml, divided into a group with reasonable glycemic control [RC: HbA1c < 8% (64 mmol/mol)] and another with a poor control [PC: HbA1c ≥ 8%, (64 mmol/mol)] after introduction of liraglutide and insulin therapy.

RESULTS

Except for HbA1c, there were no statistical differences between RC and PC groups. Basal insulin doses were adjusted to achieve the fasting plasma glucose of 90-120 mg/dl. HbA1c was significantly improved in both groups, from 9.6% ± 1.6 (81 mmol/mol) and 7.0% ± 0.6 (53 mmol/mol) to 8.0% ± 1.5 (64 mmol/mol) and 6.8 ± 0.5% (51 mmol/mol). Reduction of body weight was significant only in RC (from 70 ± 16 kg to 68 ± 16 kg, p < 0.01). All patients from RC group and 58% of PC group reached HbA1c < 8% without hypoglycemia.

CONCLUSION

This observation persuades us to propose the liraglutide and insulin combination to patients with C-peptide ≥ 1.5 ng/ml, regardless of the HbA1c.

Metabolic Health, Insulin, and Breast Cancer: Why Oncologists Should Care About Insulin

Studies investigating the potential link between adult pre-menopausal obesity [as measured by body mass index (BMI)] and triple-negative breast cancer have been inconsistent. Recent studies show that BMI is not an exact measure of metabolic health; individuals can be obese (BMI > 30 kg/m²) and metabolically healthy or lean (BMI < 25 kg/m²) and metabolically unhealthy. Consequently, there is a need to better understand the molecular signaling pathways that might be activated in individuals that are metabolically unhealthy and how these signaling pathways may drive biologically aggressive breast cancer. One key driver of both type-2 diabetes and cancer is insulin. Insulin is a potent hormone that activates many pathways that drive aggressive breast cancer biology. Here, we review (1) the controversial relationship between obesity and breast cancer, (2) the impact of insulin on organs, subcellular components, and cancer processes, (3) the potential link between insulin-signaling and cancer, and (4) consider time points during breast cancer prevention and treatment where insulin-signaling could be better controlled, with the ultimate goal of improving overall health, optimizing breast cancer prevention, and improving breast cancer survival.

Differences in efficacy evaluation endpoints in clinical trials for claiming reduction of post-prandial glycemic response between Japan and the European Union

When evaluating the efficacy of foods with health claims (FHC), each country sets different standards for efficacy evaluation endpoints in clinical trials, which may result in a barrier, namely the case that the claim that is allowed in Japan cannot be used on the label in another region and vice versa. We aimed to investigate the efficacy evaluation endpoints used in clinical trials of FFCs containing ID and submitted in Japan, in reference to the EU requirements for substantiating the claim, namely "reduction of post-prandial glycemic responses". We detected only one difference in efficacy evaluation endpoints, which was insulin levels. We found 67 such clinical trials cited in systematic literature reviews on finished products or functional substance(s). Of these, 43 (64%) trials lacked insulin assessment. Particularly, for foods that were claimed to reduce post-prandial glycemic responses, the EU does not consider a claim to be substantiated unless insulin levels have been evaluated. Our findings suggest the need for standardization of requirements for FHC between Japan and the EU. This consideration will strengthen the evidence for clinical significance of ID and allow products labeled with this health claim to be more widely distributed.

Relationship between glucose variability evaluated by continuous glucose monitoring and clinical factors, including glucagon-stimulated insulin secretion in patients with type 2 diabetes

AIMS

To evaluate the clinical factors affecting daily and day-to-day glucose variability by using continuous glucose monitoring.

METHODS

We performed a cross-sectional analysis of patients with type 2 diabetes mellitus (T2DM) who underwent a glucagon stimulation test (GST) with 72 h of continuous glucose monitoring. Daily glucose variability was evaluated by mean amplitude of glycemic excursions [MAGE], percentage coefficient of variation for glucose (%CV), and day-to-day glucose variability (mean of daily differences [MODD]) by using continuous glucose monitoring. Correlations of clinical factors, including insulin secretion ability by the GST with MAGE, %CV, and MODD, were analyzed.

RESULTS

In 83 T2DM with insulin therapy, age and hemoglobin A_1c (HbA_1c) correlated with MAGE and %CV, fasting plasma glucose with MAGE and MODD, and increment of C-peptide immunoreactivity (ΔCPR) by GST correlated inversely with MAGE, %CV, and MODD. In 126 T2DM without insulin therapy, age, diastolic blood pressure, and triglycerides correlated with MODD, HbA_1c with MAGE and MODD, and ΔCPR inversely correlated with %CV. Use of α-glucosidase inhibitors inversely correlated with %CV, whereas that of sulfonylurea was associated with MAGE and %CV.

CONCLUSIONS

These results suggest that ΔCPR correlated with stability of glycemic control, whereas poorly controlled diabetes is associated with increase in glucose variability. α-glucosidase inhibitors may be superior to sulfonylureas in reducing the glucose variability in T2DM.

Fetal androgen signaling defects affect pancreatic β-cell mass and function, leading to glucose intolerance in high-fat diet-fed male rats

We previously demonstrated that androgen signaling expands pancreatic β-cell mass in the sexual maturation period (Am J Physiol Endocrinol Metab 314: E274-E286, 2018). The aim of this study was to elucidate whether fetal androgen signaling plays important roles in β-cell mass development and β-cell function in adulthood, defects of which are associated with type 2 diabetes mellitus. In the pancreas of male fetuses, androgen receptor (AR) was strongly expressed in the cytoplasm and at the cell membrane of Nkx6.1-positive β-cell precursor cells but was markedly reduced in insulin-positive β-cells. Administration of the anti-androgen flutamide to pregnant dams during late gestation reduced β-cell mass and Ki67-positive proliferating β-cells at birth in a male-specific manner without affecting body weight. The decrease of β-cell mass in flutamide-exposed male rats was not recovered when rats were fed a standard diet, whereas it was fully recovered when rats were fed a high-fat diet (HFD), at 6 and 12 wk of age. Flutamide exposure in utero led to the development of glucose intolerance in male rats due to a decrease in insulin secretion when fed HFD but not standard diet. Insulin sensitivity did not differ between the two groups irrespective of diet. These results indicated that the action of fetal androgen contributed to β-cell mass expansion in a sex-specific manner at birth and to the development of glucose intolerance by decreasing the secretion of insulin in HFD-fed male rats. Our data demonstrated the involvement of fetal androgen signaling in hypothesized sex differences in the developmental origins of health and disease by affecting pancreatic β-cell function.

Response to insulin degludec and insulin glargine 300 U/mL: Which of these two insulins causes less hypoglycemia?

To minimize the influence of possible confounding factors, the study was carried out in a cross‐over manner. Using flash glucose monitoring, insulin glargine 300 U/mL showed less nocturnal hypoglycemia than insulin degludec 100 U/mL . Examination of insulin degludec 100 U/mL nocturnal hypoglycemia by combined oral medications suggested that metformin combination might be the cause of nocturnal hypoglycemia.

Trends in global prescribing of antidiabetic medicines in primary care: A systematic review of literature between 2000-2018

The aim of this review was to examine changes in the use of diabetes medicines prescribed to treat type 2 diabetes in the primary care setting. Five electronic databases were searched using strict inclusion/exclusion criteria. The quality of eligible studies was appraised using the Newcastle-Ottawa Scale. Findings show the trend has been away from using sulfonylurea and towards the use of metformin. The introduction of newer drugs has not shifted treatment outcomes and glycaemic control. It was not possible to determine how clinicians make choices about the medicines they prescribe for T2DM, or what influences those choices.

Preserving β-cell function is the major determinant of diabetes remission following laparoscopic sleeve gastrectomy in Japanese obese diabetic patients

Laparoscopic sleeve gastrectomy has been proven effective in treating obesity-associated type 2 diabetes mellitus (T2DM). However, reports of the effect of laparoscopic sleeve gastrectomy on glucose metabolism in Japanese obese patients with T2DM are rare. The aim of this study was to evaluate the effects of laparoscopic sleeve gastrectomy on glucose tolerance in Japanese obese patients with T2DM, and to analyze factors influencing diabetes remission after surgery. This was a retrospective analysis of data for 24 consecutive patients with T2DM who underwent laparoscopic sleeve gastrectomy. We investigated weight loss and its impact on T2DM 1 year postoperatively. We also compared baseline characteristics and postoperative factors between patients who achieved diabetes remission and patients without remission. Mean body weight loss and percent total weight loss were 23.9 kg and 23.3%, respectively. Mean hemoglobin A1c levels dropped from 7.3 ± 0.3% to 6.1 ± 0.2%, and 18 patients (75%) achieved diabetes remission 1 year postoperatively. Patients achieving remission had significantly lower hemoglobin A1c levels (p = 0.026), higher fasting C-peptide values (p < 0.001), shorter diabetes duration (p < 0.001), lower insulin requirement (p = 0.002), and higher area under the insulin response curve (p < 0.001) and insulinogenic index (p < 0.001) during oral glucose tolerance testing. In conclusion, laparoscopic sleeve gastrectomy is an effective treatment for Japanese obese patients with T2DM. Preserving insulin secretion is the major determinant of diabetes remission.

Comparison of the Efficacy of Repaglinide Versus the Combination of Mitiglinide and Voglibose on Glycemic Variability in Japanese Patients with Type 2 Diabetes

BACKGROUND

Glycemic variability is a risk factor for total death and cardiovascular events. There are no obvious guidelines for the direct treatment of glycemic variability, but it can be improved with the treatment of postprandial hyperglycemia.

OBJECTIVE

We compared the effect of repaglinide versus the combination of mitiglinide and voglibose, used to improve postprandial hyperglycemia, on glycemic variability in Japanese patients with type 2 diabetes.

METHODS

We performed an open-label randomized cross-over trial between April 2016 and April 2018. Patients with type 2 diabetes who were admitted to our hospital were enrolled in our study (n = 12). Glycemic variability. was assessed using a continuous glucose monitoring system.

RESULTS

The average glucose level of the repaglinide phase (146.1 ± 20.7 mg/dl) and the combination of mitiglinide and voglibose phase (132.3 ± 19.8 mg/dl) were similar (P = 0.10). The standard division (P = 0.0005), coefficient of variation (P = 0.006), and mean amplitude of glycemic excursion (P = 0.002) of glucose were lower in the combination of mitiglinide and voglibose phase than in the repaglinide phase.

CONCLUSION

Treatment with the combination of mitiglinide and voglibose might be more effective than repaglinide for the improvement of glycemic variability.

Cross-population analysis for functional characterization of type II diabetes variants

BACKGROUND

As Genome-Wide Association Studies (GWAS) have been increasingly used with data from various populations, it has been observed that data from different populations reveal different sets of Single Nucleotide Polymorphisms (SNPs) that are associated with the same disease. Using Type II Diabetes (T2D) as a test case, we develop measures and methods to characterize the functional overlap of SNPs associated with the same disease across populations.

RESULTS

We introduce the notion of an Overlap Matrix as a general means of characterizing the functional overlap between different SNP sets at different genomic and functional granularities. Using SNP-to-gene mapping, functional annotation databases, and functional association networks, we assess the degree of functional overlap across nine populations from Asian and European ethnic origins. We further assess the generalizability of the method by applying it to a dataset for another complex disease - Prostate Cancer. Our results show that more overlap is captured as more functional data is incorporated as we go through the pipeline, starting from SNPs and ending at network overlap analyses. We hypothesize that these observed differences in the functional mechanisms of T2D across populations can also explain the common use of different prescription drugs in different populations. We show that this hypothesis is concordant with the literature on the functional mechanisms of prescription drugs.

CONCLUSION

Our results show that although the etiology of a complex disease can be associated with distinct processes that are affected in different populations, network-based annotations can capture more functional overlap across populations. These results support the notion that it can be useful to take ethnicity into account in making personalized treatment decisions for complex diseases.

Leaner Women with Impaired Insulin Secretion Accounts for about 40% of Gestational Diabetes Mellitus in Japan

AIM

To identify the involvement of leanness and impaired insulin secretion with Japanese gestational diabetes mellitus (GDM).

METHOD

A cross-sectional study was conducted comprising 219 at-risk pregnant women who underwent a 75g glucose tolerance test at a single institute in Tokyo, Japan. We identified GDM and normal glucose tolerance (NGT). The cut-off value of the homeostasis model assessment insulin resistance (HOMA-IR) for detecting GDM was determined. The GDM group was divided into subgroups according to insulin resistance based on the cut-off value of HOMA-IR. We compared the prepregnancy body mass index (BMI) and homeostasis model assessment of β-cell function (HOMA-β) between the group comprising low insulin resistance (LIR) and the group comprising high insulin resistance (HIR).

RESULTS

Seventy GDM cases and 149 NGT cases were identified. By using receiver operating characteristic curve analysis, the HOMA-IR cut-off value was determined to be 1.41. Twenty-five GDM cases (36%) were classified as LIR and forty-five GDM cases (64%) were classified as HIR. The background including indications for having 75gOGTT and the gestational age having 75gOGTT did not differ between groups. The BMI of the LIR group was significantly lower than that of the HIR group (20.9±2.8 vs. 24.4 ± 5.5, p<0.01), and the HOMA-β of the LIR group was significantly lower than that of the HIR group (95.5±30.3 vs. 146.0±70.1, p<0.01). A positive linear correlation was found between BMI and HOMA-β in cases of GDM (r=0.27, p=0.02).

CONCLUSION

Leanness with impaired insulin secretion is deeply involved in Japanese gestational diabetes mellitus.

Hyperglycemic status is associated with an elevated risk of osteoporotic fracture in community-dwelling elderly Japanese men: The Fujiwara-kyo osteoporosis risk in men (FORMEN) cohort study

PURPOSE

Patients with type 2 diabetes mellitus have an increased fracture risk. However, population-based studies on the association between glycemic status and fracture risk are scarce, and none have targeted a Japanese population. In addition, patients in the lowest category of hemoglobin A1c (HbA1c) do not always show the lowest risk. This study aimed to clarify the association between glycemic status and fracture risk in community-dwelling elderly Japanese men.

METHODS

A total of 1992 men aged ≥65 years completed baseline measurements including fasting plasma glucose (FPG), HbA1c, bone density, and an interview regarding past disease history. Osteoporotic fractures (OPFs) that occurred during the 5-year follow-up period were determined through interviews. An OPF at the spine, hip, proximal humerus, or distal radius was defined as a major OPF (MOF).

RESULTS

After excluding participants who had a history of type 1 diabetes mellitus and thiazolidinedione therapy, 1951 men were analyzed. Men with hyperglycemia in the diabetic range had a significantly higher risk of OPF compared with those with normoglycemia, after adjusting for confounding factors including insulin therapy (hazard ratio (HR): 2.76, 95% confidence interval (CI): 1.17, 6.50 in FPG ≥ 126 mg/dl; HR: 2.49, 95% CI: 1.07, 5.77 in HbA1c ≥ 6.5%). An elevated risk of MOF was observed in participants in the prediabetic HbA1c category (HR: 2.15, 95% CI: 1.00, 4.62 in 5.7% ≤ HbA1c < 6.5%) in addition to those in the diabetic category. The intermediate glycemic status group showed intermediate risk, suggesting that the association was linear.

CONCLUSIONS

Hyperglycemia was associated linearly with elevated fracture risk in community-dwelling elderly men. MOF risk may be elevated in Japanese elderly men with prediabetic glycemic status.

Novel murine model of congenital diabetes: The insulin hyposecretion mouse

AIMS/INTRODUCTION

Diabetic animal models have made an enormous contribution to our understanding of the etiology of diabetes and the development of new medications. The aim of the present study was to develop and characterize a novel, non-obese murine strain with spontaneous diabetes - the insulin hyposecretion (ihs) mouse.

MATERIALS AND METHODS

During the development of the ICGN.B6-Tns2WT strain as the control for the ICGN-Tns2nph congenital nephrotic strain, diabetic mice were discovered and named ihs mice. Intraperitoneal insulin tolerance test, oral glucose tolerance test and an insulin secretion experiment by the pancreas perfusion system were carried out on ihs mice. The pancreatic islets were examined histologically, and the mRNA expression of pancreatic β-cell-specific genes or genes associated with monogenic diabetes was examined by RT-qPCR.

RESULTS

The ihs mice showed several distinctive diabetes-related characteristics: (i) the onset of diabetes was observed only in the male mice; (ii) there were no differences in insulin content between the ihs and control mice; (iii) impaired insulin secretion was elicited by glucose, potassium chloride and sulfonylureas; (iv) there was a significant reduction of relative β-cell volume with no signs of inflammation or fibrosis; (v) they showed a normal glycemic response to exogenous insulin; and (vi) the mice were not obese.

CONCLUSIONS

The ihs mouse provides a novel murine model of congenital diabetes that shows insulin secretion failure. This model allows not only an analysis of the progression of diabetes, but also the identification of unknown genes involved in insulin secretion.

Clinical impact of insulin resistance on pulmonary vein isolation outcome in patients with paroxysmal atrial fibrillation

INTRODUCTION

The relationship between insulin resistance and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) remains unclear.

METHODS

Drug-refractory 114 paroxysmal AF patients (89 males, 62 ± 8 years) who underwent successful PVI were enrolled. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated and a value of ≥2.5 was defined as insulin resistant. The left atrial volume index (LAVI) was measured using echocardiography before and 1 year after PVI. Tumor necrosis factor-α (TNF-α) and TGF-β1 serum levels were measured before PVI, and the left atrium (LA) conduction velocity was calculated. The patients were divided into two groups (group 1: HOMA-IR < 2.5, n = 81; group 2: HOMA-IR ≥ 2.5, n = 33).

RESULTS

The LAVI between the two groups before PVI did not significantly differ (P > 0.05), nor did TNF-α (7.7 ± 2.0 vs 7.5 ± 1.0 pg/mL; P = 0.149) or TGF-β1 (28.4 ± 12.0 vs 27.6 ± 10.3 ng/mL; P = 0.757). LAVI before and 1 year after PVI in each group did not change. The conduction velocity of group 2 was slower than that of group 1 (0.7 ± 0.1 vs 1.1 ± 0.3 m/s, P < 0.001). Kaplan-Meier analysis showed significantly higher AF recurrence in group 2 than that in group 1 ( P = 0.019). Cox multivariable analysis revealed that insulin resistance was an independent predictor of recurrence (hazard ratio 1.287, P = 0.004).

CONCLUSION

Our results suggest that insulin resistance promotes LA electrical remodeling and might be related to AF recurrence after PVI.

The Association of Cardio-Ankle Vascular Index and Ankle-Brachial Index with Macroangiopathy in Patients with Type 2 Diabetes Mellitus

AIMS

This study elucidates the association of macroangiopathy development in type 2 diabetes patients with various arteriosclerosis risk factors (ARFs) and results of cardio-ankle vascular index (CAVI) and ankle-brachial pressure index (ABI).

METHODS

The correlation between current and past macroangiopathy development, with ARFs or CAVI/ABI data, was retrospectively analyzed using multivariate logistic regression in 816 patients with type 2 diabetes at a single center. C-statistics combining some independent variables selected using the stepwise method were evaluated.

RESULTS

CAVI was significantly correlated with macroangiopathies, including coronary artery disease (CAD), arteriosclerosis obliterans (ASO), and stroke with odds ratios (OR) of 1.20, 1.22, and 1.19, respectively. ABI significantly correlated with ASO and stroke with respective OR of 13.6 and 2.47, but not with CAD. Areas under the receiver operating characteristic curves (ROCs) revealed the accuracy of detecting ASO and stroke was increased by the combination of CAVI＋ABI (0.94 and 0.74, respectively). However, areas under the ROC for the presence of CAD can be increased by the combination of CAVI and ARFs especially including dyslipidemia.

CONCLUSION

CAVI/ABI and some ARFs are useful tools in daily clinical care units to identify the current and past existence of macroangiopathy in patients with type 2 diabetes, but the prediction weights using these factors were different among CAD, ASO, and stroke.

Effects of Meal Timing on Postprandial Glucose Metabolism and Blood Metabolites in Healthy Adults

We examined the effects of meal timing on postprandial glucose metabolism, including the incretin response and metabolites in healthy adults. Nineteen healthy young men completed two trials involving blood collection in a fasting state and at 30, 60 and 120 min after meal provision in a random order: (1) morning (~0900 h) and (2) evening (~1700 h). The blood metabolome of eight participants was analyzed using capillary electrophoresis-mass spectrometry. Postprandial glucose concentrations at 120 min (p = 0.030) and glucose-dependent insulinotropic polypeptide concentrations (p = 0.005) at 60 min in the evening trials were higher than those in the morning trials. The incremental area under the curve values of five glycolysis, tricarboxylic acid cycle and nucleotide-related metabolites and 18 amino acid-related metabolites were higher in the morning trials than those in the evening trials (p < 0.05). Partial least-squares analysis revealed that the total metabolic change was higher in the morning. Our study demonstrates that a meal in the evening exacerbates the state of postprandial hyperglycemia in healthy adults. In addition, this study provides insight into the difference of incretion and blood metabolites between breakfast and dinner, indicating that the total metabolic responses tends to be higher in the morning.

Serum selenoprotein P, but not selenium, predicts future hyperglycemia in a general Japanese population

We aimed to test the hypothesis that selenoprotein P (SELENOP), a hepatokine involved in the development of both insulin resistance and impaired insulin production in mice, is related to future onset of hyperglycemia in humans. 76 healthy non-pregnant human subjects without diabetes underwent oral glucose tolerance test (OGTT) at baseline and 4-years follow-up. Nine subjects developed either impaired glucose tolerance or type 2 diabetes at follow-up. At baseline, SELENOP concentrations correlated negatively with insulinogenic index, but not with homeostasis model assessment-estimated insulin resistance (HOMA-IR). Multivariate analysis showed that baseline SELENOP predicted fasting plasma glucose at follow-up independently of the other parameters. The receiver operating characteristic (ROC) curve analysis showed that baseline concentrations of serum SELENOP, but not of selenium, were a reliable test to predict future onset of glucose intolerance. In conclusion, elevation of circulating SELENOP, but not of circulating selenium, was positively and independently associated with future onset of glucose intolerance in a general Japanese population.

Comparative study of the effects of ipragliflozin and sitagliptin on multiple metabolic variables in Japanese patients with type 2 diabetes: A multicentre, randomized, prospective, open-label, active-controlled study

In the present randomized study, we assessed the efficacy of ipragliflozin compared with sitagliptin in 124 Japanese patients with type 2 diabetes. Sodium-glucose co-transporter-2 inhibitor-naïve and incretin-related agent-naïve patients were randomly assigned to receive additional 50 mg ipragliflozin or sitagliptin. The primary endpoint was the proportion of participants with >0.5% decrease in glycated haemoglobin (HbA1c) without body weight gain at 12 weeks. For secondary endpoints, we measured several biomarkers related to metabolic changes. After 12 weeks, 53.9% of participants in the ipragliflozin and 42.9% in the sitagliptin group reached the primary endpoint (P = 0.32). Decreases in homeostatic model assessment of insulin resistance, body fat percentage and skeletal muscle mass index, and increases in free fatty acids, ketone body concentration and HDL cholesterol levels were greater in the ipragliflozin group. Increases in homeostatic model assessment of β-cell function and decreases in proinsulin-to-insulin ratio were greater in the sitagliptin group. No serious adverse events occurred in either group. In conclusion, ipragliflozin had beneficial effects on fat reduction, insulin resistance and lipid metabolism, while sitagliptin had beneficial effects on β-cell function.

Factors associated with regression from prediabetes to normal glucose tolerance in a Korean general population: A community-based 10-year prospective cohort study

AIM

A proportion of people with prediabetes convert back to normal glucose tolerance. We sought to determine the clinical variables associated with conversion from prediabetes to normal glucose tolerance, with a focus on insulin secretory capacity, insulin sensitivity and body composition.

METHODS

We followed 1731 people with prediabetes at baseline from the Korean Genome and Epidemiology Study every 2 years for 10 years. Oral glucose tolerance tests (OGTT) were performed, and muscle and fat mass were estimated using bioelectrical impedance analysis.

RESULTS

During 10 years of follow-up, 36% (623/1731) of people with prediabetes converted to normal glucose tolerance. Higher baseline fasting glucose, 2-h OGTT glucose and triglyceride levels were inversely associated with this conversion. Higher 60-min insulinogenic index (IGI₆₀ ) at baseline was independently associated with this conversion [HR per sd (95% CI) 1.09 (1.02-1.17); P = 0.01]. However, other indices reflecting insulin sensitivity, including the composite insulin sensitivity index, were not associated with this conversion. In addition, a higher baseline muscle to fat ratio was independently associated with conversion to normal glucose tolerance [HR per sd (95% CI) 1.15 (1.04-1.26); P = 0.005]. People with conversion to normal glucose tolerance showed a greater increase in the 60-min insulinogenic index and disposition index and a smaller decrease in the composite insulin sensitivity index compared with people without conversion during 10 years of follow-up (all p-values < 0.001).

CONCLUSION

A higher insulin secretory capacity at baseline and during follow-up and higher baseline muscle to fat ratio were independently associated with an improvement in glucose tolerance in Korean adults with prediabetes.

Mealtime dosing of a rapid-acting insulin analog reduces glucose variability and suppresses daytime cardiac sympathetic activity: a randomized controlled study in hospitalized patients with type 2 diabetes

OBJECTIVE

Glucose variability induces endothelial dysfunction and cardiac autonomic nerve abnormality. Here we compared the effects of mealtime insulin aspart and bedtime insulin detemir on glucose variability, endothelial function, and cardiac autonomic nerve activity among Japanese patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Forty hospitalized patients received either mealtime insulin aspart or bedtime insulin detemir treatment for 2 weeks. We assessed glucose variability indices, including M-value, SD of blood glucose level, and mean blood glucose (MBG) level. Flow-mediated dilation (FMD) of the brachial artery was measured as an index of endothelial function. Low-frequency power, high-frequency power, and the low-frequency to high-frequency power ratio (LF:HF ratio) derived via heart rate variability analysis using a Holter ECG were employed as indices of cardiac autonomic nerve function.

RESULTS

M-values and MBG levels showed a considerably greater decrease in the insulin aspart group than in the insulin detemir group (p=0.006  vs p=0.001); no change in FMD was observed in either group. Daytime LF:HF ratio significantly decreased in the insulin aspart group but not in the insulin detemir group. Total insulin dose at endpoint in the insulin aspart group was significantly higher than that in the insulin detemir group (p<0.001).

CONCLUSIONS

Mealtime insulin aspart reduced glucose variability to a greater extent than bedtime insulin detemir in patients with type 2 diabetes. Despite the need for higher insulin doses, insulin aspart decreased daytime cardiac sympathetic nerve activity. These properties may subsequently help reduce cardiovascular risks.

TRIAL REGISTRATION NUMBER

UMIN000008369.

Choice of Treatment Regimen as Add-On to Insulin in Japanese Patients with Type 2 Diabetes Mellitus: Physicians' Perspective in a Real-World Setting, Insight from a Web Survey

INTRODUCTION

The Japanese guidelines emphasize treatment individualization and intensification with oral anti-diabetes drugs and glucagon-like peptide-1 receptor agonists (OADGs) as add-on therapy to insulin in the management of type 2 diabetes mellitus (T2DM). However, a step-wise treatment algorithm is not clearly defined in the Japanese guidelines. This study explores the treatment factors and patient characteristics for selecting the OADGs as add-on therapy to insulin from physicians' perspectives in a real-world setting in Japan.

METHODS

This web-based survey comprised a questionnaire designed for physicians (diabetologists with board certification and general physicians without board certification) across Japan. The primary endpoint was the proportion of treatment factors and patient characteristics influencing the selection of OADGs as add-on therapy to insulin by the physicians.

RESULTS

In total, 549 physicians participated. The mean number of patients treated with insulin by diabetologists (102.2 ± 91.2) in the past 6 months was higher than the number by general physicians (35.1 ± 44.3). The dipeptidyl peptidase-4 (DPP-4) inhibitors were the most frequently prescribed OADGs as add-on therapy to insulin types among the physicians (75.4-88.2%), followed by metformin (65.2-76.3%). The treatment factors influencing the choice of a DPP-4 inhibitor were glycated hemoglobin (HbA1c) and postprandial glucose (PPG) lowering effect, frequency of administration, effect on glucagon, and ease of use in patients with renal or liver impairment. For metformin, cost-effectiveness was the key deciding factor. The patient characteristics for the choice of DPP-4 inhibitors among diabetologists were predominantly PPG, concern about hypoglycemia, diabetes complications, and adherence to diet and exercise. For metformin, it was age, body mass index (BMI), insulin resistance, renal and liver function, and economic status of the patients.

CONCLUSION

DPP-4 inhibitors, followed by metformin, were the most frequently prescribed OADGs in combination with insulin in a real-world setting in Japan. The diabetologists considered more drug characteristics for DPP-4 inhibitor or metformin-insulin combinations. The treatment factors and patient characteristics for the choice of DPP-4 inhibitors and metformin were comparable across different insulin types.

FUNDING

Novartis Pharma K.K.

Empagliflozin as add-on to linagliptin in a fixed-dose combination in Japanese patients with type 2 diabetes: Glycaemic efficacy and safety profile in a 52-week, randomized, placebo-controlled trial

AIMS

This double-blind, randomized, placebo-controlled trial (ClinicalTrials.gov NCT02453555) evaluated the efficacy and safety of empagliflozin (Empa) 10 or 25 mg as add-on to linagliptin (Lina) 5 mg (fixed-dose combination, Empa/Lina 10/5 or 25/5) in insufficiently controlled Japanese type 2 diabetes patients.

METHODS

The trial (40 sites; May 2015-March 2017) involved screening 433 adults (≥20 years) who were treatment-naive or were using one oral antidiabetic drug for ≥12 weeks, which was discontinued at enrolment. Patients with HbA1c 7.5%-10.0% after ≥16 weeks of using Lina (pre-enrolment or during a 16-week, open-label period) and 2 weeks of using placebo (Plc) for Empa/Lina 10/5, plus Lina, were randomized (2:1) to once-daily Empa/Lina 10/5 (n = 182) or Plc/Lina 10/5 (n = 93) for 24 weeks. Patients with HbA1c ≥ 7.0% at Week 24 received Empa/Lina up-titrated to 25/5 (n = 126) or the corresponding placebo (n = 80), per randomization, from Week 28; 172 Empa/Lina and 84 Plc/Lina patients completed 52 weeks.

RESULTS

Change from baseline in HbA1c was greater (P < .0001) with Empa/Lina than with Plc/Lina at Week 24 (primary outcome, -0.93% vs 0.21%; adjusted mean difference, -1.14%) and Week 52 (-1.16% vs 0.06%; adjusted mean difference, -1.22%). More patients with HbA1c < 7.0% and greater decreases in fasting plasma glucose, body weight and systolic blood pressure were seen in the Empa/Lina group than in the Plc/Lina group. Empa/Lina was well tolerated. The adverse events that were more frequent with Empa/Lina were known empagliflozin-associated events (eg, increased urination, increased blood ketones). There were no adjudication-confirmed diabetic ketoacidosis events or lower limb amputations.

CONCLUSIONS

These results support the notion that empagliflozin-linagliptin in fixed-dose combination is a therapeutic option for Japanese patients with type 2 diabetes.

Two-hour post-challenge hyperglycemia, but not fasting plasma glucose, associated with severity of coronary artery disease in patients with angina

INTRODUCTION

Postprandial hyperglycemia plays a pivotal role in cardiovascular disease. However, few studies have investigated associations between the severity of coronary artery disease (CAD) and postprandial glucose levels in angina patients without known diabetes before coronary angiography.

METHODS

Subjects who were admitted for coronary angiography due to angina and were in stable condition after discharge were recruited. A standard 75-g oral glucose tolerance test (OGTT) was performed at outpatient visits approximately 2-4 weeks after hospital discharge, and fasting and post-challenge blood glucose were measured. Twenty-six volunteers in our hospital staff served as the healthy group. CAD severity was graded using the SYNTAX and Jeopardy scoring systems.

RESULTS

The subjects in the angina group had a higher body mass index, higher fasting glucose, and higher 2-h postprandial glucose than those in the healthy group. The SYNTAX and Jeopardy scores were significantly associated with 2-h postprandial blood glucose (correlation coefficients = 0.164 and 0.187, respectively) but not with fasting glucose. Linear regression analyses revealed that SYNTAX and Jeopardy scores were independently associated with glucose levels at 120 min after OGTT (SYNTAX 95%CI = 0.003-0.103; Jeopardy score 0.002-0.027) but not with fasting glucose.

CONCLUSION

CAD severity is associated with blood glucose levels after oral glucose challenge in patients without known diabetes before coronary angiography, suggesting that CAD patients should be routinely screened for post-challenge blood glucose.

There is a Close Association Between the Recovery of Liver Injury and Glycemic Control after SGLT2 Inhibitor Treatment in Japanese Subjects with Type 2 Diabetes: A Retrospective Clinical Study

INTRODUCTION

Sodium-glucose co-transporter 2 (SGLT2) inhibitors function not only to reduce hyperglycemia but also to ameliorate liver injury and reduce body weight. The aim of this study was to examine in which subjects SGLT2 inhibitors are more effective for glycemic control, liver injury, and obesity in Japanese subjects with type 2 diabetes mellitus.

METHODS

We enrolled a total of 156 subjects with type 2 diabetes who initiated SGLT2 inhibitor treatment after September 1, 2014 in Kawasaki Medical School (Protocol No. 2375). We evaluated the alteration of glycemic control, liver injury, body mass composition, and various clinical parameters.

RESULTS

SGLT2 inhibitors significantly ameliorated glycemic control and improved liver injury in Japanese subjects with type 2 diabetes. SGLT2 inhibitors were more effective for liver injury when glycemic control was improved with SGLT2 inhibitors. In multivariate analyses, the amelioration of glycemic control was an independent determinant factor for the improvement of liver damage in Japanese subjects with type 2 diabetes. The reverse was also correct; the improvement of liver damage was an independent determinant factor for the amelioration of glycemic control.

CONCLUSION

Recovery of liver injury with SGLT2 inhibitor treatment was closely associated with their effects on glycemic control in Japanese subjects with type 2 diabetes.

Effect of race on the glycaemic response to sitagliptin: Insights from the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS)

AIM

Pooled efficacy studies suggest that glycaemic responses to dipeptidyl-peptidase 4 inhibitors in type 2 diabetes are greatest in Asians, who may also respond better to alpha-glucosidase inhibitors. We assessed the glycaemic impact of sitagliptin by race in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS), and whether this was enhanced in Asians with concomitant acarbose therapy.

MATERIALS AND METHODS

TECOS enrolled 14 671 patients with type 2 diabetes, cardiovascular disease and HbA1c of 48-64 mmol/mol (6.5%-8.0%), and randomized them, double-blind, to sitagliptin or placebo. There were 3265 patients (22.3%) from Asian countries. Background glucose-lowering therapies were unaltered for the first 4 months post randomization unless clinically essential, facilitating comparison of sitagliptin-associated effects in self-identified East Asian, Other (South) Asian, White Caucasian, Hispanic, Black and Indigenous groups.

RESULTS

Median baseline HbA1c by race was 54 to 57 mmol/mol (7.1%-7.4%). Mean 4-month reduction in placebo-adjusted HbA1c was greatest in East Asians (-6.6 mmol/mol [-0.60%] vs ≤6.0 mmol/mol [≤0.55%] in other groups), with significantly greater reduction vs the 2 largest groups (White Caucasians, Other Asians; P < .0001) after adjustment for covariates. After the first 4 months, East and Other Asians were more likely to initiate additional oral therapy (metformin and/or sulfonylureas) than insulin vs White Caucasians (P < .0001). Acarbose use increased in the Asian patients, but no glycaemic interaction with allocated study medication was observed (adjusted P = .12).

CONCLUSIONS

The greatest initial reduction in HbA1c with sitagliptin in the TECOS population was in East Asians. No enhanced glycaemic effect was seen when sitagliptin was given with acarbose.

Predictors of Incident Type 2 Diabetes Mellitus in Japanese Americans with Normal Fasting Glucose Level

BACKGROUND

Little is known about the natural course of normal fasting glucose (NFG) in Asians and the risk factors for future diabetes.

METHODS

A total of 370 Japanese Americans (163 men, 207 women) with NFG levels and no history of diabetes, aged 34 to 75 years, were enrolled. Oral glucose tolerance tests were performed at baseline, 2.5, 5, and 10 years after enrollment.

RESULTS

During 10 years of follow-up, 16.1% of participants met criteria for diabetes diagnosis, and 39.6% of subjects still had NFG levels at the time of diabetes diagnosis. During 5 years of follow-up, age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01 to 1.10; P=0.026) and family history of diabetes (OR, 3.24; 95% CI, 1.42 to 7.40; P=0.005) were independently associated with future diabetes diagnosis; however, fasting glucose level was not an independent predictor. During 10 years of follow-up, family history of diabetes (OR, 2.76; 95% CI, 1.37 to 5.54; P=0.004), fasting insulin level (OR, 1.01; 95% CI, 1.00 to 1.02; P=0.037), and fasting glucose level (OR, 3.69; 95% CI, 1.13 to 12.01; P=0.030) were associated with diabetes diagnosis independent of conventional risk factors for diabetes.

CONCLUSION

A substantial number of subjects with NFG at baseline still remained in the NFG range at the time of diabetes diagnosis. A family history of diabetes and fasting insulin and glucose levels were associated with diabetes diagnosis during 10 years of follow-up; however, fasting glucose level was not associated with diabetes risk within the relatively short-term follow-up period of 5 years in subjects with NFG.

Postpartum risk of diabetes and predictive factors for glucose intolerance in East Asian women with gestational diabetes

AIMS

Women with a history of gestational diabetes mellitus (GDM) are likely to develop postpartum diabetes mellitus (DM). We examined women in the early stages of pregnancy who were at high risk of postpartum DM progression to establish a follow-up method for early detection.

METHODS

We performed the oral glucose tolerance test (OGTT) and identified predictive factors for postpartum impaired glucose tolerance (IGT) or DM in 77 women after GDM, for 2 years after delivery, retrospectively. Cutoff values for each factor were determined. We classified these women with GDM into four groups using these predictive factors and evaluated postpartum glucose intolerance (GI) in each group.

RESULTS

In total, 44.1% of the women with a GDM history had developed postpartum GI within 2 years. We determined three risk factors for postpartum GI: elevated glucose level 120 min after a 75-g OGTT (Glu120), elevated glycated hemoglobin (HbA1c) level at diagnosis, and perinatal complications. The cutoff Glu120 and the HbA1c level were 155 mg/dl and 5.3% (34 mmol/mol), respectively. Type 2 DM developed in 53.8% of women, and IGT developed in 38.5% of women within 2 years in groups with high Glu120 and high HbA1c.

CONCLUSIONS

High-risk groups require careful follow-up observation.

CREB1 functional polymorphisms modulating promoter transcriptional activity are associated with type 2 diabetes mellitus risk in Chinese population

The cAMP responsive element binding protein 1 (CREB1) is a ubiquitous transcription factor that contributes to the regulation of gluconeogenesis. The mechanisms of the CREB1 function remain largely unknown. In this study, we aimed to explore genetic variations in CREB1 promoter region and determine whether these loci affect transcriptional activity and risk on type 2 diabetes (T2D). Three polymorphisms were identified and designated as MU₁, MU₂ and MU₃, respectively. Genotypic distribution analysis revealed that MU₁ genotypes presented similar distribution between T2D and healthy controls (P > 0.05), while the MU₂ and MU₃ showed significant differences (P < 0.05). Haplotypic blocks of the three loci were constructed, and H1-TGA, H2-TTT and H3-ATT had higher frequencies in T2D patients than those in controls. Association studies revealed that the three loci significantly affected plasma glucose, glycated hemoglobin and insulin secretion. Disequilibrium analysis identified that the MU₂ and MU₃ variants were strongly linked in T2D (r² = 0.348, D' = 1.0). Further analysis indicated that MU₂ (TT vs GG, OR = 2.38, 95%CI = 1.19-4.77, P = 0.01) and MU₃ (AA vs TT, OR = 1.16, 95%CI = 1.19-4.77, P = 0.04) were significantly associated with T2D in dominant genotypes. Luciferase assay showed that T-A haplotype from the highly linked MU₂ and MU₃ exhibited maximal promoter activity, which was consistent with the correlation results. We concluded that the TT genotype of MU₂ and the AA genotype of MU₃ could be used as molecular markers for evaluating the risk on T2D.

One-hour oral glucose tolerance test plasma glucose at gestational diabetes diagnosis is a common predictor of the need for insulin therapy in pregnancy and postpartum impaired glucose tolerance

Aims/Introduction

Gestational diabetes mellitus (GDM) is a risk for adverse perinatal outcomes, and patients with a history of GDM have an increased risk of impaired glucose tolerance (IGT). Here, we carried out two non‐interventional and retrospective studies of GDM patients in Japan.

Materials and Methods

In the first study, we enrolled 529 GDM patients and assessed predictors of the need for insulin therapy. In the second study, we enrolled 185 patients from the first study, and assessed predictors of postpartum IGT.

Results

In the first study, gestational weeks at GDM diagnosis and history of pregnancy were significantly lower, and pregestational body mass index, family history of diabetes mellitus, 1‐ and 2‐h glucose levels in a 75‐g oral glucose tolerance test (OGTT), the number of abnormal values in a 75‐g OGTT, and glycated hemoglobin were significantly higher in participants receiving insulin therapy. In the second study, 1‐ and 2‐h glucose levels in a 75‐g OGTT, the number of abnormal values in a 75‐g OGTT, glycated hemoglobin, and ketone bodies in a urine test were significantly higher in participants with OGT. Logistic regression analysis showed that gestational weeks at GDM diagnosis, 1‐h glucose levels in a 75‐g OGTT and glycated hemoglobin were significant predictors of the need for insulin therapy, and 1‐h glucose levels in a 75‐g OGTT at diagnosis and ketone bodies in a urine test were significant predictors for postpartum IGT.

Conclusions

Antepartum 1‐h glucose levels in a 75‐g OGTT was a predictor of the need for insulin therapy in pregnancy and postpartum IGT.

Cardiovascular Disease in Japanese Patients with Type 2 Diabetes Mellitus

Individuals with diabetes have a two- to four-fold increased risk of coronary artery disease (CAD) and higher mortality rates than those without diabetes. Because not only microvascular but also macrovascular disease in patients with diabetes are known to predispose patients to a lower quality of life as well as lead to higher mortality rates, identifying and managing risk factors of CAD is of clinical relevance in diabetes care. A number of antihyperglycemic drugs are currently approved for the treatment of hyperglycemia in patients with type 2 diabetes mellitus (T2DM), with several new drugs having been developed during the last decade. Diabetes-related complications have been substantially reduced worldwide. However, in view of the current situation in which both the prevalence of obesity and glucose abnormality have increased worldwide, including Japan, diet and exercise remain the crucial means of treatment for patients with diabetes. Furthermore, predicting the development of CAD is essential. This review summarizes data from recent studies on cardiovascular disease in patients with T2DM, focusing on clinical trials and big data, including studies involving Japanese individuals.

Vegetarian diet, change in dietary patterns, and diabetes risk: a prospective study

Background/objectives

Vegetarian diets are inversely associated with diabetes in Westerners but their impact on Asians—whose pathophysiology differ from Westerners—is unknown. We aim to investigate the association between a vegetarian diet, change in dietary patterns and diabetes risk in a Taiwanese Buddhist population.

Methods

We prospectively followed 2918 non-smoking, non-alcohol drinking Buddhists free of diabetes, cancer, and cardiovascular diseases at baseline, for a median of 5 years, with 183 incident diabetes cases confirmed. Diet was assessed through a validated food frequency questionnaire at baseline and a simple questionnaire during follow-ups. Incident cases of diabetes were ascertained through follow-up questionnaires, fasting glucose and HbA1C. Stratified Cox Proportional Hazards Regression was used to assess the effect of diets on risk of diabetes.

Results

Consistent vegetarian diet was associated with 35% lower hazards (HR: 0.65, 95% CI: 0.46, 0.92), while converting from a nonvegetarian to a vegetarian pattern was associated with 53% lower hazards (HR: 0.47, 95% CI: 0.30, 0.71) for diabetes, comparing with nonvegetarians while adjusting for age, gender, education, physical activity, family history of diabetes, follow-up methods, use of lipid-lowering medications, and baseline BMI.

Conclusion

Vegetarian diet and converting to vegetarian diet may protect against diabetes independent of BMI among Taiwanese.

Impact of diabetes-related gene polymorphisms on the clinical characteristics of type 2 diabetes Chinese Han population

We investigated the correlation between type 2 diabetes (T2D)-related genes and the clinical characteristics of T2D in the Chinese Han population. Our study included 319 patients and 387 controls. Age, gender, clinical features, medications intake and biochemical blood profiles were analyzed. Genotyping was performed on a total of 18 single nucleotide polymorphisms previously reported to be associated with T2D. Our analyses revealed that the CT genotype of ARHGAP22 rs4838605 is associated with T2D risk. Upon analyzing the subjects’ clinical characteristics, we found that for rs2811893, the TT genotype correlated with high creatinine levels, while the AA genotype of rs17045754 and the TT genotype of rs4838605 correlated with elevated triglyceride levels. In addition, the AA genotype of rs17376456 and the TT genotype of rs6214 (p = 0.006) correlated with elevated hemoglobin A1c levels. Lastly, those carrying the TT genotype of rs7772697 and the CA genotype of rs3918227 exhibited higher mean body mass index and Cystatin C than controls. Our results showing that the ARHGAP22 gene is associated with an increased risk of T2D, and that seven SNPs in MYSM1, PLXDC2, ARHGAP22 and HS6ST3 promote T2D progression and could help predict the clinical course of T2D in patients at risk.