Glucose tolerance, insulin secretion, and insulin sensitivity in nonobese and obese Japanese subjects

Association between serum leptin concentrations and homeostasis model assessment-insulin resistance of 2.5 and higher in normal weight Japanese women

Normal weight insulin resistant phenotype was characterized in 251 Japanese female university students using homeostasis model assessment-insulin resistance. Birth weight, body composition at age 20, cardiometabolic traits and dietary intake were compared cross-sectionally between insulin sensitive (< 1.6, n = 194) and insulin resistant (2.5 and higher, n = 16) women. BMI averaged < 21 kg/m² and waist < 72 cm and did not differ between two groups. The percentage of macrosomia and serum absolute and fat-mass corrected leptin concentrations were higher in insulin resistant women although there was no difference in birth weight, fat mass index, trunk/leg fat ratio and serum adiponectin. In addition, resting pulse rate, serum concentrations of free fatty acids, triglycerides and remnant-like particle cholesterol were higher in insulin resistant women although HDL cholesterol and blood pressure did not differ. In multivariate logistic regression analyses, serum leptin (odds ratio:1.68, 95% confidential interval:1.08-2.63, p = 0.02) was associated with normal weight insulin resistance independently of macrosomia, free fatty acids, triglycerides, remnant-like particle cholesterol and resting pulse rate. In conclusion, normal weight IR phenotype may be associated with increased plasma leptin concentrations and leptin to fat mass ratio in young Japanese women, suggesting higher leptin production by body fat unit.

The multiscale characterization and constitutive modeling of healthy and type 2 diabetes mellitus Sprague Dawley rat skin

In type 2 diabetes mellitus (T2DM), elevated glucose level impairs the biochemistry of the skin which may result in alteration of its mechanical and structural properties. The several aspects of structural and mechanical changes in skin due to T2DM remain poorly understood. To fill these research gaps, we developed a non-obese T2DM rat (Sprague Dawley (SD)) model for investigating the effect of T2DM on the in vivo strain stress state, mechanical and structural properties of skin. In vivo strain and mechanical anisotropy of healthy and T2DM skin were measured using the digital imaging correlation (DIC) technique and DIC coupled bulge experiment, respectively. Fluorescence microscopy and histology were used to assess the collagen and elastin fibers microstructure whereas nanoscale structure was captured through atomic force microscopy (AFM). Based on the microstructural observations, skin was modeled as a multilayer membrane where in and out of plane distribution of collagen fibers and planar distribution of elastin fibers were cast in constitutive model. Further, the state of in vivo stresses of healthy and T2DM were measured using model parameters and in vivo strain in the constitutive model. The results showed that T2DM causes significant loss in in vivo stresses (p < 0.01) and increase in anisotropy (p < 0.001) of skin. These changes were found in good correlation with T2DM associated alteration in skin microstructure. Statistical analysis emphasized that increase in blood glucose concentration (HbA1c) was the main cause of impaired biomechanical properties of skin. The presented data in this study can help to understand the skin pathology and to simulate the skin related clinical procedures. STATEMENT OF SIGNIFICANCE: Our study is significant as it presents findings related to the effect of T2DM on the physiologic stress strain, structural and mechanical response of SD rat skin. In this study, we developed a non-obese T2DM SD rat model which mimics the phenotype of Asian type 2 diabetics (non-obese). Several structural and mechanical characterization techniques were explored for multiscale characterization of healthy and T2DM skin. Further, based on microstructural information, we presented the constitutive models that incorporate the real microstructure of skin. The presented results can be helpful to simulate the realistic mechanical response of skin during various clinical trials.

Dietary carbohydrate and the risk of type 2 diabetes: an updated systematic review and dose-response meta-analysis of prospective cohort studies

We did this study to clarify the association between carbohydrate intake and the risk of type 2 diabetes (T2D) and potential effect modification by geographical location. PubMed, Scopus and Web of Science were searched to find prospective cohort studies of dietary carbohydrate intake and T2D risk. A random-effects dose–response meta-analysis was performed to calculate the summary hazard ratios (HRs) and 95%CIs. The quality of cohort studies and the certainty of evidence was rated using the Newcastle–Ottawa Scale and GRADE tool, respectively. Eighteen prospective cohort studies with 29,229 cases among 607,882 participants were included. Thirteen studies were rated to have high quality, and five as moderate quality. The HR for the highest compared with the lowest category of carbohydrate intake was 1.02 (95%CI: 0.91, 1.15; I² = 67%, GRADE = low certainty). The HRs were 0.93 (95%CI: 0.82, 1.05; I² = 58%, n = 7) and 1.26 (95%CI: 1.11, 1.44; I² = 6%, n = 6) in Western and Asian countries, respectively. Dose–response analysis indicated a J shaped association, with the lowest risk at 50% carbohydrate intake (HR_50%: 0.95, 95%CI: 0.90, 0.99) and with risk increasing significantly at 70% carbohydrate intake (HR_70%: 1.18, 95%CI: 1.03, 1.35). There was no association between low carbohydrate diet score and the risk of T2D (HR: 1.14, 95%CI: 0.89, 1.47; I² = 90%, n = 5). Carbohydrate intake within the recommended 45–65% of calorie intake was not associated with an increased risk of T2D. Carbohydrate intake more than 70% calorie intake might be associated with a higher risk.

Establishment and Validation of a New Predictive Model for Insulin Resistance based on 2 Chinese Cohorts: A Cross-Sectional Study

BACKGROUND

Visceral adiposity plays a key role in the development of insulin resistance (IR), so surrogate index that can indicate visceral obesity may have higher predictive value for IR. This study aimed to establish and validate a new predictive model including indicator of visceral obesity for IR.

METHODS

The study population consisted of two cohorts. The derivation cohort was a group of 667 patients with newly diagnosed type 2 diabetes and the population undergoing a routine health checkup was the validation cohort. The predictive model was established by the logistic regression analysis. Its value for predicting IR was compared with other surrogate indices by the receiver operating characteristic curve.

RESULTS

The odds ratio (OR) of age, visceral fat area (VFA), triglyceride (TG), fasting plasma glucose (FPG), and alanine aminotransferase (ALT) for IR was 1.028 (95% CI, 1.008-1.048) (P < 0.01), 1.016 (95% CI, 1.009-1.023) (P < 0.001), 1.184 (95% CI, 1.005-1.396) (P < 0.05), 1.334 (95% CI, 1.225-1.451) (P < 0.001), and 1.021 (95% CI, 1.001-1.040) (P < 0.05). The formula of the predictive model was (0.0293 × age + 1.4892 × Ln VFA + 0.4966 × Ln TG + 2.784 × Ln FPG + 0.6906 × Ln ALT)/2. The area under the curve was the largest among all the previously reported predictors.

CONCLUSIONS

This study established and validated a predicting model for IR and confirmed its predictive value in comparison with other surrogate indicators, which will offer a simple and effective tool to measure IR in future large population studies.

Thiolated Chitosan as an Intestinal Absorption Carrier with Hesperidin Encapsulation for Obesity Treatment

Obesity is characterized as abnormal or excessive fat accumulation harmful to one's health, linked to hormonal imbalances, cardiovascular illness, and coronary artery disease. Since the disease stems mainly from overconsumption, studies have aimed to control intestinal absorption as a route for treatment. In this study, chitosan-thioglycolic acid (CT) was developed as a physical barrier in the gastrointestinal tracts to inhibit nutrient uptake. CT exhibits a superior mucoadhesive property compared to chitosan both in vitro and in vivo for the ability to form disulfide bonds with the intestinal mucosa. For CT as a potential drug delivery platform, hesperidin, a herb for bodyweight control in traditional Chinese medication, is encapsulated in CT and can be released consistently from this absorption barrier. In animal studies, CT encapsulated with hesperidin (CTH) not only results in a weight-controlling effect but limits adipose accumulation by hindering absorption, suggesting a potential role in obesity treatment. Neither CT nor CTH exhibit cytotoxicity or produce adverse immunological reactions in vivo.

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

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

Comparison of the contributions of impaired beta cell function and insulin resistance to the development of type 2 diabetes in a Japanese community: the Hisayama Study

AIMS/HYPOTHESIS

Our aim was to compare the contributions of impaired beta cell function (IBF) and insulin resistance with the development of type 2 diabetes in a Japanese community.

METHODS

A total of 2094 residents aged 40-79 years without diabetes underwent a health examination including a 75 g OGTT in 2007. Participants were divided into four groups according to the presence or absence of IBF (insulinogenic index/HOMA-IR ≤28.5) and insulin resistance (HOMA-IR ≥1.61) and were followed up for 7 years (2007-2014). Cox's proportional hazards model was used to estimate HRs and 95% CIs for type 2 diabetes. The population attributable fractions (PAFs) due to IBF, insulin resistance, and their combination were calculated.

RESULTS

At baseline, the prevalence of isolated IBF, isolated insulin resistance, and both IBF and insulin resistance were 5.4%, 24.1% and 9.5%, respectively. During the follow-up period, 272 participants developed type 2 diabetes. The multivariable-adjusted HRs (95% CI) and PAFs (95% CI) for type 2 diabetes were 6.3 (4.3, 9.2) and 13.3% (8.7, 17.7) in the participants with isolated IBF, 1.9 (1.3, 2.7) and 10.5% (4.0, 16.6) in those with isolated insulin resistance, and 8.0 (5.7, 11.4) and 29.3% (23.0, 35.1) in those with both IBF and insulin resistance, respectively, compared with the participants without either.

CONCLUSIONS/INTERPRETATION

The present study suggests that the combination of IBF and insulin resistance makes the main contribution to the development of type 2 diabetes in Japanese communities.

Efficacy of once-daily glucagon-like peptide-1 receptor agonist lixisenatide as an add-on treatment to basal insulin in Asian and white adults with type 2 diabetes mellitus: An individual-level pooled analysis of phase III studies

AIMS/INTRODUCTION

The prevalence and pathophysiological background of type 2 diabetes mellitus vary across ethnicities, and can affect treatment responses. Adding lixisenatide to basal insulin (BI) in type 2 diabetes mellitus patients has shown improvements in glycated hemoglobin (HbA1c) and postprandial glycemic (PPG) excursions, without increasing hypoglycemic events. We aim to compare the efficacy of lixisenatide in Asian and white patients inadequately controlled with basal insulin.

MATERIALS AND METHODS

An individual-level pooled analysis of two multi-national phase III studies, GetGoal-L and GetGoal-L-C, was carried out to assess the efficacy of lixisenatide versus placebo as an add-on treatment to BI ± metformin in Asian and white patients with type 2 diabetes mellitus. Change in HbA1c, 2-h PPG and PPG excursion were analyzed, along with possible predictors of glycemic control.

RESULTS

Pooled data showed that baseline characteristics were similar between Asian and white patients with the exception of bodyweight, body mass index and BI dose being higher in white patients. After 24 weeks, lixisenatide reduced HbA1c in both ethnic groups, with no statistically significant difference between the two groups (Asian patients least squares mean difference -0.49, 95% confidence interval -0.68 to - 0.30 and white patients least squares mean difference -0.45, 95% confidence interval -0.63 to - 0.26; P = 0.6287). Similarly, no significant difference was found in 2-h PPG reduction between both groups (least squares mean difference for Asian vs white patients: -3.37 vs -3.93; P = 0.3203). Treatment with lixisenatide contributed to HbA1c reduction of -0.56% after adjustment of baseline HbA1c level in Asian patients, and -0.41% in white patients.

CONCLUSIONS

Adding lixisenatide to BI significantly reduced HbA1c and 2-h PPG levels in both Asian and white participants with type 2 diabetes mellitus. No differences in treatment effect were observed between the two populations.

Basic concepts and unique features of human circadian rhythms: implications for human health

Most physiological functions and behaviors exhibit a robust approximately 24-hour rhythmicity (circadian rhythm) in the real world. These rhythms persist under constant conditions, but the period is slightly longer than 24 hours, suggesting that circadian rhythms are endogenously driven by an internal, self-sustained oscillator. In mammals, including humans, the central circadian pacemaker is located in the hypothalamic suprachiasmatic nucleus. The primary zeitgeber for this pacemaker is bright sunlight, but nonphotic time cues also affect circadian rhythms. The human circadian system uniquely exhibits spontaneous internal desynchronization between the sleep-wake cycle and core body temperature rhythm under constant conditions and partial entrainment of the sleep-wake cycle in response to nonphotic time cues. Experimental and clinical studies of human circadian rhythms must take into account these unique features. This review covers the basic concepts and unique features of the human circadian system, the mechanisms underlying phase adjustment of the circadian rhythms by light and nonphotic time cues (eg, physical exercise), and the effects of eating behavior (eg, chewing frequency) on the circadian rhythm of glucose metabolism.

Frequency of consumption of balanced meals, bodyweight gain and incident risk of glucose intolerance in Japanese men and women: A cohort study

AIMS/INTRODUCTION

This cohort study assessed the risk for bodyweight gain and development of glucose intolerance based on the frequency of consumption of balanced meals including grain, fish or meat and vegetables.

MATERIALS AND METHODS

The participants (8,573 men, 3,327 women) were employees of a company in Japan. A self-administered questionnaire was used to evaluate the frequency of balanced meal consumption. Bodyweight changes and the incidence of glucose intolerance (glycated hemoglobin >6.0%) during the 3-year follow-up period were determined through annual health examinations.

RESULTS

The mean bodyweight change over a period of 3 years was 0.78 kg for men and 0.84 kg for women. A lower frequency of balanced meals was associated with a higher bodyweight gain for men (P for trend = 0.004), but not for women. During the study, 464 men and 115 women developed glucose intolerance. Overall, the frequency of balanced meals was not associated with the risk of glucose intolerance in either sex. However, the interaction between the frequency of balanced meals and degree of obesity had a significant effect on the incidence of glucose intolerance in men (P = 0.005), with less frequent consumption of balanced meals being associated with a higher risk for glucose intolerance among men with a BMI ≥25.0 kg/m2 (P for trend = 0.007).

CONCLUSIONS

A higher frequency of balanced meals, including grain, fish or meat and vegetable dishes - important components of healthy Japanese food - was associated with a lower risk of glucose intolerance in obese men, but not in non-obese men and women.

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Body mass index and colorectal cancer risk: A Mendelian randomization study

Traditional observational studies have reported a positive association between higher body mass index (BMI) and the risk of colorectal cancer (CRC). However, evidence from other approaches to pursue the causal relationship between BMI and CRC is sparse. A two-sample Mendelian randomization (MR) study was undertaken using 68 single nucleotide polymorphisms (SNPs) from the Japanese genome-wide association study (GWAS) and 654 SNPs from the GWAS catalogue for BMI as sets of instrumental variables. For the analysis of SNP-BMI associations, we undertook a meta-analysis with 36 303 participants in the Japanese Consortium of Genetic Epidemiology studies (J-CGE), comprising normal populations. For the analysis of SNP-CRC associations, we utilized 7636 CRC cases and 37 141 controls from five studies in Japan, and undertook a meta-analysis. Mendelian randomization analysis of inverse-variance weighted method indicated that a one-unit (kg/m2 ) increase in genetically predicted BMI was associated with an odds ratio of 1.13 (95% confidence interval, 1.06-1.20; P value <.001) for CRC using the set of 68 SNPs, and an odds ratio of 1.07 (1.03-1.11, 0.001) for CRC using the set of 654 SNPs. Sensitivity analyses robustly showed increased odds ratios for CRC for every one-unit increase in genetically predicted BMI. Our MR analyses strongly support the evidence that higher BMI influences the risk of CRC. Although Asians are generally leaner than Europeans and North Americans, avoiding higher BMI seems to be important for the prevention of CRC in Asian populations.

TYK2 Promoter Variant Is Associated with Impaired Insulin Secretion and Lower Insulin Resistance in Japanese Type 2 Diabetes Patients

Accumulating evidence has suggested that viral infection causes type 1 diabetes due to direct β-cell damage and the triggering of autoimmune reactivity to β cells. Here, we elucidated that the tyrosine kinase 2 (Tyk2) gene, encoding an interferon receptor signaling molecule, is responsible for virus-induced diabetes in mice, and its promoter variant confers a risk of type 1 diabetes in humans. This study investigated the relationship between a TYK2 promoter variant (TYK2PV) and insulin secretion in type 2 diabetes patients. TYK2PV status was determined using direct DNA sequencing and its associations with fasting insulin, C-peptide, and homeostatic model assessment of insulin resistance (HOMA-IR) were evaluated in type 2 diabetes patients without sulfonylurea or insulin medication. Of the 172 patients assessed, 18 (10.5%) showed TYK2PV-positivity. Their body mass index (BMI) was significantly lower than in those without the variant (23.4 vs. 25.4 kg/m², p = 0.025). Fasting insulin (3.9 vs. 6.2 μIU/mL, p = 0.007), C-peptide (1.37 vs. 1.76 ng/mL, p = 0.008), and HOMA-IR (1.39 vs. 2.05, p = 0.006) were lower in those with than in those without the variant. Multivariable analysis identified that TYK2PV was associated with fasting insulin ≤ 5 μIU/mL (odds ratio (OR) 3.63, p = 0.025) and C-peptide ≤ 1.0 ng/mL (OR 3.61, p = 0.028), and also lower insulin resistance (HOMA-IR ≤ 2.5; OR 8.60, p = 0.042). TYK2PV is associated with impaired insulin secretion and low insulin resistance in type 2 diabetes. Type 2 diabetes patients with TYK2PV should be carefully followed in order to receive the appropriate treatment including insulin injections.

Evaluation of carotid intima media thickness in children with idiopathic nephrotic syndrome

AIM

Aim of the study was to determine if carotid intima media thickness in children with idiopathic nephrotic syndrome is greater than in healthy subjects, and to assess whether carotid intima media thickness in children with nephrotic syndrome is associated with clinical (including disease duration, cumulative dose of steroids, number of relapses) and biochemical parameters.

METHODS

A cross-sectional study included 40 patients with nephrotic syndrome (mean age 11.7±4.7 years). Steroid dependent nephrotic syndrome was established in 32 patients (80%), while 8 (20%) had steroid resistant nephrotic syndrome. Control group consisted of 20 age and gender matched healthy children. Blood pressure based on 24-h ambulatory blood pressure monitoring (ABPM), carotid intima media thickness, fasting glucose, insulin, HbA1c, lipid concentrations were measured in all children.

RESULTS

A significant difference was detected in carotid intima media thickness values (P=0.036). Children with nephrotic syndrome had significantly greater carotid intima media thickness compared with healthy children (0.42±0.06 and 0.38±0.03mm). Carotid intima-media thickness was positively associated with duration of nephrotic syndrome (r=0.45; P=0.004), body mass index (r=0.48; P=0.002), daytime systolic blood pressure (r=0.46; P=0.003) and night-time systolic blood pressure (r=0.52; P=0.001). Multiple linear regression showed that duration of nephrotic syndrome was the only independent predictor of carotid intima media thickness in children with nephrotic syndrome (R²=0.244; β=0.327; P=0.037).

CONCLUSION

The findings of the present study suggest subclinical vascular damage in patients with nephrotic syndrome. Duration of nephrotic syndrome was the only independent predictor of carotid intima media thickness.

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

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

Glucagon-Like Peptide-1 Receptor Agonist Prevented the Progression of Hepatocellular Carcinoma in a Mouse Model of Nonalcoholic Steatohepatitis

Glucagon-like peptide-1 (GLP-1) receptor agonists are used to treat diabetes, but their effects on nonalcoholic steatohepatitis (NASH) and the development of hepatocellular carcinoma (HCC) remain unclear. In this study, mice with streptozotocin- and high-fat diet-induced diabetes and NASH were subcutaneously treated with liraglutide or saline (control) for 14 weeks. Glycemic control, hepatocarcinogenesis, and liver histology were compared between the groups. Fasting blood glucose levels were significantly lower in the liraglutide group than in the control group (210.0 ± 17.3 mg/dL vs. 601.8 ± 123.6 mg/dL), and fasting insulin levels were significantly increased by liraglutide (0.18 ± 0.06 ng/mL vs. 0.09 ± 0.03 ng/mL). Liraglutide completely suppressed hepatocarcinogenesis, whereas HCC was observed in all control mice (average tumor count, 5.5 ± 3.87; average tumor size, 8.1 ± 5.0 mm). Liraglutide significantly ameliorated steatosis, inflammation, and hepatocyte ballooning of non-tumorous lesions in the liver compared with the control findings, and insulin-positive β-cells were observed in the pancreas in liraglutide-treated mice but not in control mice. In conclusion, liraglutide ameliorated NASH and suppressed hepatocarcinogenesis in diabetic mice. GLP-1 receptor agonists can be used to improve the hepatic outcome of diabetes.

Review of methods for detecting glycemic disorders

Prediabetes (intermediate hyperglycemia) consists of two abnormalities, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) detected by a standardized 75-gram oral glucose tolerance test (OGTT). Individuals with isolated IGT or combined IFG and IGT have increased risk for developing type 2 diabetes (T2D) and cardiovascular disease (CVD). Diagnosing prediabetes early and accurately is critical in order to refer high-risk individuals for intensive lifestyle modification. However, there is currently no international consensus for diagnosing prediabetes with HbA1c or glucose measurements based upon American Diabetes Association (ADA) and the World Health Organization (WHO) criteria that identify different populations at risk for progressing to diabetes. Various caveats affecting the accuracy of interpreting the HbA1c including genetics complicate this further. This review describes established methods for detecting glucose disorders based upon glucose and HbA1c parameters as well as novel approaches including the 1-hour plasma glucose (1-h PG), glucose challenge test (GCT), shape of the glucose curve, genetics, continuous glucose monitoring (CGM), measures of insulin secretion and sensitivity, metabolomics, and ancillary tools such as fructosamine, glycated albumin (GA), 1,5- anhydroglucitol (1,5-AG). Of the approaches considered, the 1-h PG has considerable potential as a biomarker for detecting glucose disorders if confirmed by additional data including health economic analysis. Whether the 1-h OGTT is superior to genetics and omics in providing greater precision for individualized treatment requires further investigation. These methods will need to demonstrate substantially superiority to simpler tools for detecting glucose disorders to justify their cost and complexity.

A novel nutritional supplement containing amino acids and chromium decreases postprandial glucose response in a randomized, double-blind, placebo-controlled study

High postprandial blood glucose levels are associated with increased mortality, cardiovascular events and development of diabetes in the general population. Interventions targeting postprandial glucose have been shown to prevent both cardiovascular events and diabetes. This study evaluates the efficacy and safety of a novel nutritional supplement targeting postprandial glucose excursions in non-diabetic adults. Sixty overweight healthy male and female participants were recruited at two centers and randomized in a double-blind, placebo-controlled, crossover design. The supplement, a water-based drink containing 2.6g of amino acids (L-Leucine, L-Threonine, L-Lysine Monohydrochloride, L-Isoleucine, L-Valine) and 250 mcg of chromium picolinate, was consumed with a standardized carbohydrate-rich meal. The primary endpoint was the incremental area under the curve (iAUC) for venous blood glucose from 0 to 120 minutes. Secondary endpoints included glucose iAUC _{0–180 minutes} and the maximum glucose concentration (C_max), for both venous and capillary blood glucose. In the intention-to-treat-analysis (n = 60) the supplement resulted in a decreased venous blood glucose iAUC_0-120min compared to placebo, mean (SE) of 68.7 (6.6) versus 52.2 (6.8) respectively, a difference of -16.5 mmol/L•min (95% CI -3.1 to -30.0, p = 0.017). The C_max for venous blood glucose for the supplement and placebo were 6.45 (0.12) versus 6.10 (<0.12), respectively, a difference of -0.35 mmol/L (95% CI -0.17 to -0.53, p<0.001). In the per protocol-analysis (n = 48), the supplement resulted in a decreased C_max compared to placebo from 6.42 (0.14) to 6.12 (0.14), a difference of -0.29 mmol/L (95% CI -0.12 to -0.47, p = 0.002). No significant differences in capillary blood glucose were found, as measured by regular bed-side glucometers. The nutritional supplement drink containing amino acids and chromium improves the postprandial glucose homeostasis in overweight adults without diabetes. Future studies should clarify, whether regular consumption of the supplement improves markers of disease or could play a role in a diet aiming at preventing the development of diabetes.

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.

Morning Mastication Enhances Postprandial Glucose Metabolism in Healthy Young Subjects

Postprandial glucose concentration is dependent on the time of day and its concentration in the morning is lower than in the evening. However, whether it is dependent on mastication at different times of the day has not been studied before. We hypothesized that mastication affects insulin-mediated glucose metabolism differently in the morning and evening in healthy individuals. Firstly, nine healthy male volunteers (22.0 ± 0.7 SEM years, body mass index 22.0 ± 1.0 kg/m²) performed a 75-g oral glucose tolerance test (OGTT). One week after the OGTT, they participated in a high-carbohydrate food (rice) consumption test with 10 or 40 chews per mouthful. Each experiment was conducted in the morning (0800 h) and evening (2000 h) on the same day. Blood samples were collected before and at 30-min intervals for 120 min after glucose or rice consumption. The incremental area under the curve (iAUC) for glucose in the OGTT was significantly lower in the morning than in the evening, whereas the iAUC for insulin was similar at both times. In participants who chewed 40 times, the iAUC for glucose after rice consumption was significantly lower in the morning than in the evening but was similar at both times in individuals who chewed 10 times. Chewing 40 times in the morning (but not the evening) significantly increased insulin secretion at 30 min. This suggests that morning mastication improves early-phase insulin secretion after rice consumption. This novel finding may aid in reducing the incidence of obesity and type 2 diabetes mellitus.

TDP-43 regulates early-phase insulin secretion via CaV1.2-mediated exocytosis in islets

TAR DNA-binding protein 43 kDa (TDP-43), encoded by TARDBP, is an RNA-binding protein, the nuclear depletion of which is the histopathological hallmark of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disorder affecting both upper and lower motor neurons. Besides motor symptoms, patients with ALS often develop nonneuronal signs including glucose intolerance, but the underlying pathomechanism is still controversial, i.e., whether it is impaired insulin secretion and/or insulin resistance. Here, we showed that ALS subjects reduced early-phase insulin secretion and that the nuclear localization of TDP-43 was lost in the islets of autopsied ALS pancreas. Loss of TDP-43 inhibited exocytosis by downregulating CaV1.2 calcium channels, thereby reducing early-phase insulin secretion in a cultured β cell line (MIN6) and β cell-specific Tardbp knockout mice. Overexpression of CaV1.2 restored early-phase insulin secretion in Tardbp knocked-down MIN6 cells. Our findings suggest that TDP-43 regulates cellular exocytosis mediated by L-type voltage-dependent calcium channels and thus plays an important role in the early phase of insulin secretion by pancreatic islets. Thus, nuclear loss of TDP-43 is implicated in not only the selective loss of motor neurons but also in glucose intolerance due to impaired insulin secretion at an early stage of ALS.

Ambient Volatile Organic Compounds and Racial/Ethnic Disparities in Gestational Diabetes Mellitus: Are Asian/Pacific Islander Women at Greater Risk?

US Asian/Pacific Islander (API) communities experience high air pollution levels. APIs may be predisposed to pancreatic β-cell dysfunction and have the highest prevalence of gestational diabetes mellitus (GDM) compared with other racial/ethnic groups. Exposure to high levels of volatile organic compounds (VOCs) impairs pancreatic β-cell function, leading to insulin resistance, but racial/ethnic differences in this association are unexamined. We analyzed singleton deliveries (n = 220,065) from the Consortium on Safe Labor (2002-2008). Exposure to 14 VOCs in each hospital referral region was based on modified Community Multiscale Air Quality models. Logistic regression estimated odds ratios for GDM associated with high (≥75th percentile) versus low (<75th percentile) VOC exposure 3 months before conception and during the first trimester of pregnancy. Preconception and first-trimester exposure to high VOC levels was associated with increased odds of GDM among whites and APIs. GDM risk was significantly higher for APIs than whites for most VOCs. Preconception benzene exposure was associated with 29% (95% confidence interval: 12, 47) increased odds of GDM among whites compared with 45% (95% confidence interval: 16, 81) increased odds among APIs. These findings highlight environmental health disparities affecting pregnant women. Increased focus on GDM risk in US API communities is warranted.

Type 1 Diabetes Mellitus Diagnosed during Follow-up of Gestational Diabetes Mellitus in the Early Postpartum Period

A 27-year-old woman with a history of gestational diabetes mellitus (GDM) developed type 1 diabetes mellitus (T1D) in the early postpartum period. Women with a history of GDM are at an increased risk of developing T1D, which is rarer than type 2 diabetes mellitus. A postpartum follow-up 75-g oral glucose tolerance test and the measurement of glutamic acid decarboxylase autoantibodies aided in the early detection of T1D in this patient. Careful attention should be paid to women with a history of GDM who exhibit clinical features suggestive of future development of T1D.

Disparities in the Efficacy of Metformin in Combination with Dipeptidyl Peptidase-4 Inhibitor as Initial Treatment Stratified by Dosage and Ethnicity: A Meta-Analysis

BACKGROUND

As initial combination therapy of metformin and dipeptidyl peptidase-4 (DPP-4) inhibitor, the efficacy and safety for the use of high dose of metformin or low dose of metformin and the efficacy and safety for the combination use for Asian and Caucasian patients were not clear.

METHODS

Double-blind randomized controlled trials comparing the efficacy of initial combination therapy of metformin and DPP-4 inhibitors with metformin monotherapy were included. The primary outcome was a result of comparisons between high-dose combination therapy and low-dose combination therapy in terms of efficacy and safety.

RESULTS

A total of 11 studies were included. The results indicated that the high-dose combination therapy showed significant decreases in hemoglobin A_1c (HbA_1c) (-0.32%, P < 0.05), fasting plasma glucose (FPG) (-0.63 mmol/L, P < 0.05), and postprandial glucose (PPG) (-0.99 mmol/L, P < 0.05), but less increase in body weight (-0.54 kg, P < 0.05) when compared with low-dose combination therapy, corrected by metformin monotherapy. Moreover, the high-dose combination therapy exhibited significant decreases in HbA_1c (-0.24%, P < 0.05), FPG (-0.54 mmol/L, P < 0.05), and PPG (-0.94 mmol/L, P < 0.05) in the Caucasian population than in the Asian population, corrected by metformin monotherapy.

CONCLUSION

As an initial treatment, the high dose of metformin in combination with DPP-4 inhibitors not only provided better glycemic control but also had less effect on weight gain compared with the low-dose combination therapy through the correction of metformin monotherapy. Moreover, initial combination therapy in the Caucasian population showed better glycemic control and less increase in body weight compared with the Asian population.

Carbohydrate status in patients with phenylketonuria

BACKGROUND

In patients with phenylketonuria (PKU), a low-phenylalanine (Phe) diet supplemented with low-protein foods and a Phe-free amino acid mixture favors a dietary intake rich in carbohydrates, but little is known about how these molecules are metabolized in this setting. The objective of the present study was to analyze carbohydrate metabolism in patients with hyperphenylalaninemia.

METHODS

We conducted a multicenter cross-sectional study to investigate biochemical markers of basal and postprandial carbohydrate metabolism in PKU patients according to age, Phe tolerance, waist circumference and body mass index (BMI), diet, tetrahydrobiopterin (BH4) supplementation, and adherence to treatment. Basal biomarkers and anthropometric parameters were also evaluated in patients with mild hyperphenylalaninemia (MHPA) and in healthy controls.

RESULTS

A total of 83 patients aged 4-52 years were studied; 68.7% had PKU and 31.3% had MHPA. 68 healthy controls of similar sex and age were also evaluated Metabolic control was adequate in 71.9% of PKU patients. Fasting glucose levels (mean 80.77 ± 8.06 mg/dL) were high in just one patient, but fasting insulin levels, with a mean of 12.74 ± 8.4 mIU/L, were altered in 15 PKU patients (26.3%) and markedly higher than in patients with MPHA (p = 0.035). Fasting insulin levels and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) were significantly higher than in healthy controls and correlated with body mass index, waist circumference, age, and also showed statistically significant differences according to diagnosis and Phe tolerance (p < 0.05). Patients under BH4 therapy had lower insulin levels and HOMA-IR. A higher mean carbohydrate intake from AA mixtures was observed in classic PKU patients. The caloric intake in the form of carbohydrates was also higher in PKU than MHPA patients (p = 0.038) and it was correlated with basal insulin (rho = 0.468, p = 0.006), HOMA-IR (rho = 0.423, p = 0.02), BMI (rho 0.533, p = 0.002), and waist circumference (rho 0.584, p = 0.0007).

CONCLUSIONS

This study shows that PKU patients are at risk of carbohydrate intolerance and insulin resistance, more evident in adults and overweight patients, probably related to their higher caloric intake in form carbohydrate content. A higher dependency of AA mixtures was demonstrated in PKU patients.

Characteristics of Glucose Metabolism in Underweight Japanese Women

Context

Japanese women have substantially lower body mass index (BMI) than women in other developed countries. The BMI of Japanese women has steadily decreased over time. However, glucose metabolism in underweight Japanese women has not been fully characterized.

Objective

The aim of this study was to investigate glucose metabolism and the physical characteristics of underweight Japanese women.

Design and Participants

We recruited 31 young (20 to 29 years of age) and 30 postmenopausal (50 to 65 years of age) underweight women. We also recruited young normal-weight women (n = 13) and postmenopausal normal-weight women (n = 10) to serve as references. We administered an oral glucose tolerance test (OGTT) and evaluated intramyocellular lipid (IMCL) levels and body composition using ¹H-magnetic resonance spectroscopy and dual-energy X-ray absorptiometry, respectively.

Results

Young underweight women had similar glucose tolerance as young normal-weight women. However, postmenopausal underweight women had a higher area under the curve (AUC) for glucose during OGTT than postmenopausal normal-weight women. In postmenopausal underweight women, 2-hour glucose levels during OGTT were negatively correlated with lean body mass (r = −0.55, P < 0.01) and insulinogenic index (r = −0.42, P = 0.02) and were positively correlated with IMCL levels (r = 0.40, P = 0.03). Compared with young underweight women, postmenopausal underweight women had a higher AUC for glucose during OGTT and a lower insulinogenic index and AUC for insulin during OGTT.

Conclusions

Postmenopausal underweight women had more impaired glucose tolerance than young underweight women. In postmenopausal underweight women, the degree of glucose tolerance impairment was associated with decreased lean body mass, increased IMCL accumulation, and impaired insulin secretion.

Insulin resistance increases the risk of incident type 2 diabetes mellitus in patients with non-alcoholic fatty liver disease

AIM

Type 2 diabetes mellitus (T2DM) is a major complication of patients with non-alcoholic fatty liver disease (NAFLD). The aim of this retrospective study is to determine the risk factors for development of T2DM in patients with biopsy-proven NAFLD.

METHODS

One hundred and sixty two consecutive patients with biopsy-proven NAFLD who received a 75-g oral glucose tolerance test were enrolled as the total cohort. Among them, we analyzed 89 patients without T2DM diagnosed by oral glucose tolerance test to estimate the cumulative rate for development of T2DM as the follow-up cohort.

RESULTS

Of 162 patients, the glucose tolerance pattern were DM in 45 patients (27.8%), impaired glucose tolerance in 68 (42.0%), and normal glucose tolerance in 49 (30.2%). Patients with NAFL tended to be more likely to have normal glucose tolerance than those with non-alcoholic steatohepatitis (NASH). The serum levels of pre- and post-load insulin were significantly higher in the NASH group. Of 89 patients without T2DM, 13 patients newly developed T2DM during a follow-up period of 5.2 years. The cumulative rate of T2DM incidence was 8.8% at the end of the 5th year and 23.4% at the end of the 10th year. Multivariate analysis identified homeostasis model of assessment - insulin resistance (≥3.85, hazard ratio 40.1, P = 0.033) as an independent risk factor for development of T2DM.

CONCLUSIONS

Patients with NASH have an underlying potential of glucose intolerance. In NAFLD patients, insulin resistance is the most important risk factor for the incidence of T2DM. Appropriate therapy against insulin resistance could be needed for patients with NAFLD to prevent development of T2DM.

Anti-prediabetic effect of rose hip (Rosa canina) extract in spontaneously diabetic Torii rats

BACKGROUND

Prediabetes, a high-risk state for developing diabetes showing impaired glucose tolerance but a normal fasting blood glucose level, has an increasing prevalence worldwide. However, no study investigating the prevention of impaired glucose tolerance at the prediabetic stage by anti-diabetic functional foods has been reported. Thus, the present study aimed to evaluate the anti-prediabetic effect of rose hip in a prediabetic rat model.

RESULTS

Spontaneously diabetic Torii (SDT) rats were supplemented with hot-water extract of rose hip at a dose of 100 mg kg^-1 body weight day^-1 for 12 weeks. The results obtained showed that the supplementation of rose hip extract improved impaired glucose tolerance, promoted insulin secretion, preserved pancreatic beta-cell function and suppressed plasma advanced glycation end-products formation of methylglyoxal-derived hydroimidazolone (MG-H1) residue and N^ϵ -carboxymethyl-lysine residues (e.g. MG-H1, control: 465.5 ± 43.8 versus rose hip: 59.1 ± 13.0 pmol mg protein^-1 , P < 0.05) in SDT rats at the prediabetic stage (12-20 weeks old).

CONCLUSION

The present study provides the first evidence showing that a hot-water extract of rose hip could exert an anti-prediabetic effect in a rat model. © 2017 Society of Chemical Industry.

Prediabetes Exhibits Decreased Disposition Index Correlated with Deterioration of Glycemic Parameters in Nonobese Japanese Subjects: A Cross-Sectional Study from Medical Examination

BACKGROUND

Prediabetes, defined as impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), likely develops to type 2 diabetes mellitus (DM) and independently increases cardiovascular risk. We employed disposition index (DI), a new metabolic parameter indicating the pancreatic beta cell function adjusted for insulin resistance, and investigated whether it could be altered in Japanese population with prediabetes and associated with early glucose intolerance.

METHODS

A total of 102 adults who underwent an oral glucose tolerance test at the medical screening were designated to normal glucose tolerance (NGT), IFG, IGT, and DM. We calculated insulinogenic index (IGI) and homeostasis model assessment (HOMA) of β cell function (HOMA-β) as insulin secretory function, HOMA-insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) as insulin resistance and DI, and assessed correlations between these indices and glycemic parameters.

RESULTS

We observed graded increase of glycemic parameters in the order of NGT, IFG, IGT, and DM. HOMA-IR was significantly higher only in DM compared with NGT, although HOMA-β, IGI, and QUICKI showed no significant differences among the groups. In contrast, DI was significantly lower in IFG, IGT, and DM compared with NGT. In correlation analysis, glycemic parameters related positively to HOMA-IR, but inversely to DI. Only two parameters, IGI and particularly DI, were significantly decreased in the subjects with 1-hr postload glucose >8.6 mmol/L previously proposed as a predictor of type 2 diabetes.

CONCLUSIONS

Our results suggest that reduction of DI promptly reflects the alteration of early glucose intolerance in Japanese population presenting with prediabetes.

Efficacy and safety of alogliptin in patients with type 2 diabetes mellitus: A multicentre randomized double-blind placebo-controlled Phase 3 study in mainland China, Taiwan, and Hong Kong

BACKGROUND

This study determined the efficacy and safety of once-daily oral alogliptin in patients from mainland China, Taiwan, and Hong Kong with type 2 diabetes mellitus.

METHODS

In this Phase 3 multicenter double-blind placebo-controlled 16-week trial, 506 patients were randomized to receive once-daily alogliptin 25 mg or placebo: 185 in the monotherapy group, 197 in the add-on to metformin group, and 124 in the add-on to pioglitazone group. The primary efficacy variable was the change from baseline (CFB) in HbA1c at Week 16; other efficacy measures included CFB to Week 16 in fasting plasma glucose (FPG), incidence of marked hyperglycemia (FPG ≥11.1 mmol/L), and the incidence of clinical HbA1c ≤6.5 % (48 mmol/mol) and ≤7.0 % (53 mmol/mol) at Week 16. Safety was assessed throughout the trial.

RESULTS

Alogliptin monotherapy provided a significantly greater decrease in HbA1c from baseline to Week 16 compared with placebo (-0.58 %; 95 % confidence interval [CI] -0.78 %, -0.37 %; P < 0.001). As an add-on to metformin or pioglitazone, alogliptin also significantly decreased HbA1c compared with placebo (-0.69 % [95 % CI -0.87 %, -0.51 %; P < 0.001] and -0.52 % [95 % CI -0.75 %, -0.28 %; P < 0.001], respectively). In any treatment group versus placebo, alogliptin led to greater decreases in FPG (P ≤ 0.004) and a higher percentage of patients who achieved an HbA1c target of ≤6.5 % and ≤7.0 % (P ≤ 0.003). No weight gain was observed in any treatment group. A similar percentage of patients experienced drug-related, treatment-emergent adverse events in the alogliptin and placebo arms. Four and two patients in the alogliptin and placebo arms, respectively, experienced mild or moderate hypoglycemia.

CONCLUSIONS

Alogliptin 25 mg once daily reduced HbA1c and FPG and enhanced clinical response compared with placebo when used as monotherapy or as an add-on to metformin or pioglitazone. Therapy with alogliptin was well tolerated.

Impact of metabolic syndrome on the incidence of type 2 diabetes in middle-aged Japanese individuals with impaired insulin secretion: the Saku study

AIMS

To assess the impact of metabolic syndrome (MetS) on the incidence of type 2 diabetes in middle-aged Japanese individuals with impaired insulin secretion (IIS).

METHODS

This cohort study included 1,702 individuals aged 40-59 without diabetes at baseline who underwent a comprehensive medical check-up between April 2008 and March 2009 at Saku Central Hospital. Participants were classified according to their IIS and insulin resistance (IR) status [normal, isolated IR (i-IR), or isolated IIS (i-IIS)] and MetS (presence or absence). They were followed up until March 2014. Type 2 diabetes was defined based on fasting and 2-h post-load plasma glucose concentrations and by the receipt of medical treatment for diabetes.

RESULTS

During 7,572 person-years of follow-up, 92 individuals developed type 2 diabetes. The incidence rates (/1,000 person-years) for type 2 diabetes in the normal without MetS, normal with MetS, i-IR without MetS, i-IR with MetS, i-IIS without MetS, and i-IIS with MetS groups were 5.3, 3.7, 11.3, 24.7, 16.7, and 59.5, respectively. The multivariable-adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) for type 2 diabetes in the normal with MetS, i-IR with MetS, and i-IIS with MetS groups, relative to the normal without MetS group, were 0.52 (0.12-2.25), 3.78 (1.93-7.42), and 7.94 (3.96-15.91), respectively. Additionally, a positive association of MetS with type 2 diabetes was observed in the i-IIS group [HR (95 % CI) 3.56 (1.88-6.73)] but not in the normal and i-IR groups.

CONCLUSIONS

The prevention of MetS is important, particularly in individuals with low insulin secretion.

Body mass index and the risk of cancer incidence in patients with type 2 diabetes in Japan: Results from the National Center Diabetes Database

AIMS/INTRODUCTION

Both type 2 diabetes and obesity increase the risk of some types of cancers, and underlying mechanisms are thought to be, at least in part, common. In the present study, we carried out a retrospective cohort study of the relationship between body mass index (BMI) categories and cancer development in Japanese type 2 diabetic patients.

MATERIALS AND METHODS

A total of 113 incident cancers including 35 cancers whose incidence was reported to be increased by obesity (27 colorectal cancers, two breast cancers in postmenopausal women, one endometrial cancer, four renal cancers and one gallbladder cancer) were identified in 2,334 type 2 diabetic patients (1,616 men and 718 women) over an average observation period of 5.1 years.

RESULTS

In men, there was no significant association between the BMI categories at the start of the observation period and the development of any cancer. In contrast, the incidence of all of the cancers in the women was significantly higher in the group with a BMI of less than 22.0 kg/m2 (hazard ratio 3.07, 95% CI 1.01-9.36). In either sex, there was no significant relationship between the BMI categories and the development of cancers whose risk is known to be increased by obesity.

CONCLUSIONS

The findings of the present study were limited by the relatively small number of patients in the cohort, which posed a danger of not finding significance. However, the results suggested that obesity did not become an additional risk factor for cancer in Japanese type 2 diabetic patients.

Optimal Cut-Offs of Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) to Identify Dysglycemia and Type 2 Diabetes Mellitus: A 15-Year Prospective Study in Chinese

Background

The optimal reference range of homeostasis model assessment of insulin resistance (HOMA-IR) in normal Chinese population has not been clearly defined. Here we address this issue using the Hong Kong Cardiovascular Risk Factor Prevalence Study (CRISPS), a prospective population-based cohort study with long-term follow-up.

Material & Methods

In this study, normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) were defined according to the 1998 World Health Organization criteria. Dysglycemia referred to IFG, IGT or T2DM. This study comprised two parts. Part one was a cross-sectional study involving 2,649 Hong Kong Chinese subjects, aged 25–74 years, at baseline CRISPS-1 (1995–1996). The optimal HOMA-IR cut-offs for dysglycemia and T2DM were determined by the receiver-operating characteristic (ROC) curve. Part two was a prospective study involving 872 subjects who had persistent NGT at CRISPS-4 (2010–2012) after 15 years of follow-up.

Results

At baseline, the optimal HOMA-IR cut-offs to identify dysglyceia and T2DM were 1.37 (AUC = 0.735; 95% confidence interval [CI] = 0.713–0.758; Sensitivity [Se] = 65.6%, Specificity [Sp] = 71.3%] and 1.97 (AUC = 0.807; 95% CI = 0.777–0.886; Se = 65.5%, Sp = 82.9%) respectively. These cut-offs, derived from the cross-sectional study at baseline, corresponded closely to the 75^th (1.44) and 90^th (2.03) percentiles, respectively, of the HOMA-IR reference range derived from the prospective study of subjects with persistent NGT.

Conclusions

HOMA-IR cut-offs, of 1.4 and 2.0, which discriminated dysglycemia and T2DM respectively from NGT in Southern Chinese, can be usefully employed as references in clinical research involving the assessment of insulin resistance.

The Association of Metabolic Syndrome with Diabetic Retinopathy: The Korean National Health and Nutrition Examination Survey 2008-2012

Aims

To explore gender differences and associations between metabolic syndrome (MetS) and its components, and diabetic retinopathy (DR) in Korean adults aged 40 years and older with diabetes.

Methods

We analyzed data from the Korean National Health and Nutrition Examination Surveys (2008–2012). In total, 2,576 type 2 diabetic participants, aged 40 and older, were evaluated. Seven standard retinal fundus photographs were obtained after pupil dilation in both eyes. DR was graded using the modified Airlie House classification system. Vision-threatening diabetic retinopathy (VTDR) included proliferative diabetic retinopathy and clinically significant macular edema. MetS was defined according to the Joint Interim Statement, proposed in 2009, by the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute. Multivariate logistic regression analysis was used to assess the relationship between MetS and its individual components with DR and VTDR.

Results

After controlling for confounders, MetS was not associated with DR in men or women. Moreover, the risk for DR or VTDR did not increase with increasing MetS components. However, high waist circumference was significantly inversely associated with VTDR (adjusted odds ratio = 0.36; 95% confidence interval = 0.14–0.93) only in men.

Conclusions

MetS was not associated with DR or VTDR in a Korean diabetic population. However, among MetS components, it seems that abdominal obesity was inversely associated with VTDR in Korean diabetic men.

Efficacy and tolerability of exenatide twice daily and exenatide once weekly in Asian versus White patients with type 2 diabetes mellitus: A pooled analysis

AIMS

The efficacy and safety of exenatide twice daily (BID) and once weekly (QW) were assessed in Asian versus White patients with type 2 diabetes mellitus (T2DM).

METHODS

This post-hoc pooled analysis evaluated patients receiving 10μg exenatide BID for 12-30 weeks or 2mg exenatide QW for 24-30 weeks in exenatide clinical development program trials. Race was self-identified.

RESULTS

A total of 4625 patients were included (exenatide BID: Asian, n=787; White, n=2223; exenatide QW: Asian, n=511; White, n=1104). At study end, glycated hemoglobin (HbA1c), fasting glucose (FG), body weight, post-prandial glucose (PPG), and PPG excursions were significantly reduced (all P<0.0001 vs baseline). For exenatide BID, HbA1c reduction was greater in Asians (P<0.0001 vs Whites), whereas HbA1c reduction did not differ by race for exenatide QW. FG reduction did not differ by race for either exenatide formulation. Weight reduction was significantly greater in Whites (P<0.0001 vs Asians), regardless of exenatide formulation. PPG reduction was greater in Asians (P<0.0001 vs Whites) for exenatide BID but did not differ by race for exenatide QW. For exenatide BID, reductions in PPG excursions for all meals were significantly greater in Asians (P<0.0001 vs Whites), whereas only post-breakfast and post-lunch excursions were significantly greater in Asians for exenatide QW (P=0.0009 and P=0.0189 vs Whites, respectively). Common adverse events included nausea, headache, and diarrhea.

CONCLUSIONS

Exenatide BID and QW improved glycemic control, including PPG, in Asian and White patients with T2DM. With exenatide BID, Asian patients exhibited significantly greater reductions in HbA1c and PPG than White patients. Both exenatide formulations were well tolerated in both groups.

Sitagliptin monotherapy has better effect on insulinogenic index than glimepiride monotherapy in Japanese patients with type 2 diabetes mellitus: a 52-week, multicenter, parallel-group randomized controlled trial

BACKGROUND

The 52-week monotherapy with the dipeptidyl peptidase-4 inhibitor sitagliptin and the sulphonylurea glimepiride on early-phase insulin secretion in Japanese patients with type 2 diabetes mellitus (T2DM) is not known.

METHODS

A randomized, parallel-group, open-label trial was conducted at 18 centers between February, 2011 and March, 2013. 171 outpatients with T2DM were recruited and randomly assigned to glimepiride or sitagliptin by minimization. Doses of glimepiride (0.25-1.0 mg/day) and sitagliptin (25-100 mg/day) were adjusted for hemoglobin A1c (HbA1c) > 6.9 %. Analyses were performed on full analysis set (FAS) of randomized subjects taking medications as allocated, and underwent 75 g oral glucose tolerance test (OGTTs) before and after treatment. The primary outcome was insulinogenic index to quantify early-phase insulin secretion after treatment, which was evaluated by analysis of covariance (ANCOVA).

RESULTS

Of 171 enrolled subjects, 68 in the sitagliptin group and 65 in the glimepiride group were included in the FAS (mean age, 64 years; baseline (HbA1c), 7.4 %). The primary outcome revealed a significantly higher insulinogenic index in the sitagliptin group than that in the glimepiride group (p = 0.036). Sitagliptin also reduced plasma glucose levels at 60 and 120 min during OGTT compared with glimepiride, while achieving a similar improvement in HbA1c during treatment. Body weight did not change in either of the two groups, and one case of hypoglycemia was observed in the glimepiride group.

CONCLUSIONS

Sitagliptin shows better effects on insulinogenic index after 52-week treatment compared with glimepiride in Japanese patients with T2DM. Trial registration University hospital Medical Information Network (UMIN) Clinical Trials Registry, No.00004791.

Sustained Decrease of Early-Phase Insulin Secretion in Japanese Women with Gestational Diabetes Mellitus Who Developed Impaired Glucose Tolerance and Impaired Fasting Glucose Postpartum

OBJECTIVE

The aim of this study was to compare glucose intolerance in the antenatal and the postpartum periods using a 75-g oral glucose tolerance test (OGTT) in the Japanese women with gestational diabetes mellitus (GDM) using a retrospective design.

PATIENTS AND METHODS

Data were obtained from 85 Japanese women with GDM who delivered from April 2011 through April 2015 and who underwent an OGTT 6–14 weeks postpartum. The women were divided into two groups based on the results of the postpartum OGTT: one group with normal glucose tolerance (NGT) and the other with impaired glucose tolerance (IGT) as well as impaired fasting glucose (IFG). We analyzed the associations between postpartum IGT–IFG and various factors.

RESULTS

Antenatally, a significant difference was observed between the groups only in the 1-hour plasma glucose level of the 75-g OGTT. Postpartum results of plasma glucose level were significantly higher at 0.5, 1, and 2 hours in the IGT–IFG group than those in the NGT group. Moreover, a significant decrease in the levels of 0.5-hour immunoreactive insulin and insulinogenic index was observed in the IGT–IFG group compared to those in the NGT group. Homeostasis model assessment-insulin resistance and homeostasis model assessment β-cell function of both groups were found to significantly decrease in the postpartum period; however, there was no significant change in the insulinogenic index of either group.

CONCLUSIONS

Our study clearly showed that the postpartum IGT and IFG levels of Japanese women with GDM are affected by impaired early-phase insulin secretion; however, insulin resistance promptly improves.

Dietary carbohydrate intake, presence of obesity and the incident risk of type 2 diabetes in Japanese men

Aims/Introduction

The present cohort study assessed the risk among Japanese men for developing type 2 diabetes, based on the percentage of energy intake from carbohydrates and degree of obesity.

Participants and Methods

The participants were 2,006 male factory employees, and the macronutrient intake of each patient was measured using a self‐administered diet history questionnaire. The incidence of diabetes was determined in annual blood examinations over a 10‐year period.

Results

During the study, 232 participants developed diabetes. The crude incidence rates (/1,000 person‐years) for different levels of carbohydrate intake as a percentage of calories consumed (<50.0, 50.0–57.4, 57.5–65.0, >65.0% of energy intake) were 16.5, 14.4, 12.7 and 17.6. Overall, carbohydrate intake was not associated with the risk of diabetes. However, there was significant interaction between carbohydrate intake and degree of obesity on the incidence of diabetes (P for interaction = 0.024). Higher carbohydrate intake was associated with elevated risk for diabetes among participants with a body mass index ≥25.0 kg/m² (P for trend = 0.034). For obese participants, the multivariate‐adjusted hazard ratio for those with carbohydrate intakes >65% energy was 2.01 (95% confidence interval 1.08–3.71), which was significantly higher than that of participants with carbohydrate intakes 50.0–57.4% energy.

Conclusions

Higher carbohydrate intake was associated with higher risk of diabetes in obese participants, but not in non‐obese participants. Obese participants with carbohydrate intakes >65% energy should reduce their intakes to levels within the desirable carbohydrate energy proportion for Japanese (50–65% energy) to prevent development of type 2 diabetes.

Changing Clinical Characteristics according to Insulin Resistance and Insulin Secretion in Newly Diagnosed Type 2 Diabetic Patients in Korea

BACKGROUND

The role of increased insulin resistance in the pathogenesis of type 2 diabetes has been emphasized in Asian populations. Thus, we evaluated the proportion of insulin resistance and the insulin secretory capacity in patients with early phase type 2 diabetes in Korea.

METHODS

We performed a cross-sectional analysis of 1,314 drug-naive patients with newly diagnosed diabetes from primary care clinics nationwide. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as an index to measure insulin resistance, which was defined as a HOMA-IR ≥2.5. Insulin secretory defects were classified based on fasting plasma C-peptide levels: severe (<1.1 ng/mL), moderate (1.1 to 1.7 ng/mL) and mild to non-insulin secretory defect (≥1.7 ng/mL).

RESULTS

The mean body mass index (BMI) was 25.2 kg/m(2); 77% of patients had BMIs >23.0 kg/m(2). Up to 50% of patients had central obesity based on their waist circumference (≥90 cm in men and 85 cm in women), and 70.6% had metabolic syndrome. Overall, 59.5% of subjects had insulin resistance, and 20.2% demonstrated a moderate to severe insulin secretory defect. Among those with insulin resistance, a high proportion of subjects (79.0%) had a mild or no insulin secretory defect. Only 2.6% of the men and 1.9% of the women had both insulin resistance and a moderate to severe insulin secretory defect.

CONCLUSION

In this study, patients with early phase type 2 diabetes demonstrated increased insulin resistance, but preserved insulin secretion, with a high prevalence of obesity and metabolic syndrome.

Socioeconomic status is positively associated with measures of adiposity and insulin resistance, but inversely associated with dyslipidaemia in Colombian children

BACKGROUND

Low socioeconomic status (SES) has been associated with higher risk of cardiometabolic diseases in developed societies, but investigation of SES and cardiometabolic risk in children in less economically developed populations is sparse. We aimed to examine associations among SES and cardiometabolic risk factors in Colombian children.

METHODS

We used data from a population-based study of 1282 children aged 6-10 years from Bucaramanga, Colombia. SES was classified according to household wealth, living conditions and access to public utilities. Anthropometric and biochemical parameters were measured at a clinic visit. Cardiometabolic risk factors were analysed continuously using linear regression and as binary outcomes-according to established paediatric cut points-using logistic regression to calculate OR and 95% CIs.

RESULTS

Mean age of the children was 8.4 (SD 1.4) and 51.1% of the sample were boys. Odds of overweight/obesity, abdominal obesity and insulin resistance were greater among higher SES. Compared with the lowest SES stratum, children in the highest SES had higher odds of overweight/obesity (OR=3.25, 95% CI 1.89 to 5.57), abdominal obesity (OR=2.74, 95% CI 1.41 to 5.31) and insulin resistance (OR=2.60, 95% CI 1.81 to 3.71). In contrast, children in the highest SES had lower odds of hypertriglyceridaemia (triglycerides ≥90th centile; OR=0.28, 95% CI 0.14 to 0.54) and low (≤10th centile) high-density lipoprotein (HDL) cholesterol (OR=0.35, 95% CI 0.15 to 0.78).

CONCLUSIONS

In Colombian children, SES is directly associated with obesity and insulin resistance, but inversely associated with dyslipidaemia (hypertriglyceridaemia and low HDL cholesterol). Our findings highlight the need to analyse cardiometabolic risk factors separately in children and to carefully consider a population's level of economic development when studying their social determinants of cardiometabolic disease.

Incretin physiology and pathophysiology from an Asian perspective

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