Factors responsible for deteriorating glucose tolerance in newly diagnosed type 2 diabetes in Japanese men

Associations between time in range and insulin secretory capacity in Japanese patients with type 2 diabetes

Impaired insulin secretory capacity is associated with high glycemic variability in patients with type 2 diabetes (T2DM). However, there are no existing reports on the association between insulin secretory capacity and time in range (TIR). This retrospective study involved 330 T2DM admitted for diabetes education who underwent intermittently scanned continuous glucose monitoring (isCGM) and had their fasting serum C-peptide immunoreactivity (S-CPR) measured within 5 days of admission. The baseline characteristics were as follows: age, 60.2 years; glycated hemoglobin (HbA1c), 9.2%; S-CPR, 2.2 ng/mL; S-CPR index (S-CPR [ng/mL]/fasting plasma glucose [mg/dL] × 100), 1.6; and TIR, 60.3%. TIR correlated significantly with the S-CPR index, which was confirmed by multivariate analysis that included various factors such as HbA1c. Receiver operating characteristic (ROC) analysis showed that 1.88 was the optimal S-CPR index level to predict TIR ≥ 70%. In addition to HbA1c and biguanide use, the S-CPR index was a significant factor associated with TIR > 70%. S-CPR index values of ≥ 1.88 also correlated significantly with TIR > 70%. In conclusion, insulin secretory capacity is associated with TIR in Japanese T2DM, suggesting that the S-CPR index might be a potentially useful biomarker insulin secretory capacity, in association with TIR.Trial registration UMIN0000254333.

Comparative effects of fixed-dose mitiglinide/voglibose combination and glimepiride on vascular endothelial function and glycemic variability in patients with type 2 diabetes: A randomized controlled trial

INTRODUCTION

The aim of this study was to compare the effects of mitiglinide/voglibose with those of glimepiride on glycemic variability and vascular endothelial function in patients with type 2 diabetes.

MATERIALS AND METHODS

It was a multicenter, open-label, randomized, crossover study. Hospitalized patients received either mitiglinide/voglibose (three times daily administration of 10 mg mitiglinide and 0.2 mg voglibose) or glimepiride (once-daily 2 mg) in random order, each for 5 days. The reactive hyperemia index (RHI) and the mean amplitude of glycemic excursions (MAGE) were measured as co-primary endpoints using reactive hyperemia peripheral arterial tonometry and continuous glucose monitoring.

RESULTS

The analysis included 30 patients (15 in each group). The RHI was 1.670 ± 0.369 during treatment with mitiglinide/voglibose and 1.716 ± 0.492 during treatment with glimepiride, with no significant difference between the two. MAGE was significantly lower in the mitiglinide/voglibose group (47.6 ± 18.5 mg/dL) than in the glimepiride group (100.6 ± 32.2 mg/dL). Although the mean blood glucose levels over the entire 24 h period were comparable between the two groups, the use of mitiglinide/voglibose was associated with a lower standard deviation of mean glucose, coefficient of variation, and mean postprandial glucose excursion compared with glimepiride. The time below range (<70 mg/dL) and the time above range (>180, >200, and 250 mg/dL) were lower in the mitiglinide/voglibose group, while the time in range (70-180 mg/dL) was higher.

CONCLUSIONS

In our short-duration randomized crossover study, although not impacting vascular endothelial function, mitiglinide/voglibose demonstrated potential benefits in reducing glycemic variability, postprandial hyperglycemia, and hypoglycemia in patients with type 2 diabetes.

Precision subclassification of type 2 diabetes: a systematic review

BACKGROUND

Heterogeneity in type 2 diabetes presentation and progression suggests that precision medicine interventions could improve clinical outcomes. We undertook a systematic review to determine whether strategies to subclassify type 2 diabetes were associated with high quality evidence, reproducible results and improved outcomes for patients.

METHODS

We searched PubMed and Embase for publications that used 'simple subclassification' approaches using simple categorisation of clinical characteristics, or 'complex subclassification' approaches which used machine learning or 'omics approaches in people with established type 2 diabetes. We excluded other diabetes subtypes and those predicting incident type 2 diabetes. We assessed quality, reproducibility and clinical relevance of extracted full-text articles and qualitatively synthesised a summary of subclassification approaches.

RESULTS

Here we show data from 51 studies that demonstrate many simple stratification approaches, but none have been replicated and many are not associated with meaningful clinical outcomes. Complex stratification was reviewed in 62 studies and produced reproducible subtypes of type 2 diabetes that are associated with outcomes. Both approaches require a higher grade of evidence but support the premise that type 2 diabetes can be subclassified into clinically meaningful subtypes.

CONCLUSION

Critical next steps toward clinical implementation are to test whether subtypes exist in more diverse ancestries and whether tailoring interventions to subtypes will improve outcomes.

Systematic review of precision subclassification of type 2 diabetes

Heterogeneity in type 2 diabetes presentation, progression and treatment has the potential for precision medicine interventions that can enhance care and outcomes for affected individuals. We undertook a systematic review to ascertain whether strategies to subclassify type 2 diabetes are associated with improved clinical outcomes, show reproducibility and have high quality evidence. We reviewed publications that deployed 'simple subclassification' using clinical features, biomarkers, imaging or other routinely available parameters or 'complex subclassification' approaches that used machine learning and/or genomic data. We found that simple stratification approaches, for example, stratification based on age, body mass index or lipid profiles, had been widely used, but no strategy had been replicated and many lacked association with meaningful outcomes. Complex stratification using clustering of simple clinical data with and without genetic data did show reproducible subtypes of diabetes that had been associated with outcomes such as cardiovascular disease and/or mortality. Both approaches require a higher grade of evidence but support the premise that type 2 diabetes can be subclassified into meaningful groups. More studies are needed to test these subclassifications in more diverse ancestries and prove that they are amenable to interventions.

The Effect of LM25 and LM50 on Hypoglycemia in Chinese T2DM Patients: Post Hoc Analysis of a Randomized Crossover Trial

INTRODUCTION

To investigate the safety of insulin lispro Mix 25 and 50 (LM25 and LM50) in hypoglycemia in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a post hoc analysis of a phase IV, randomized, crossover clinical trial in Chinese patients with T2DM switching from premixed human insulin 70/30 (PHI70/30) to LM25 or LM50. Eighty-one subjects received a two-stage crossover protocol of either LM25 or LM50 twice daily for 16 weeks. Habitual diet was taken, and self-monitoring of blood glucose (SMBG) was performed throughout the study period. High-carbohydrate diet (HCD), high-fat diet (HFD) and habitual diet patterns were taken, and 72 h continuous glucose monitoring (CGM) was performed at the last 3 days of each treatment stage.

RESULTS

The frequencies of nocturnal hypoglycemia in LM50 were lower than those in LM25 under a Chinese habitual diet pattern. The related factors of hypoglycemia in patients with T2DM treated with a LM25 or LM50 regimen were the weight-based daily mean insulin dose and the type of combined oral hypoglycemic agents. Under both HCD and habitual diet patterns, the optimal cut point values of bedtime glucose predicting nocturnal hypoglycemia in LM50 were lower than those in LM25.

CONCLUSIONS

The risk of nocturnal hypoglycemia in the LM50 regimen was lower than that in the LM25 regimen under the HCD pattern, and the safety range of bedtime glucose for the LM50 regimen was wider than that of the LM25 regimen in Chinese T2DM patients. Premixed insulin analogs combined with acarbose were more helpful to reduce the incidence of hypoglycemia.

TRIAL REGISTRATION

http://www.chictr.org.cn #ChiCTR-TTRCC-12002516.

Four Plasma Glucose and Insulin Responses to a 75 g OGTT in Healthy Young Japanese Women

The incidence of diabetes has been gradually increasing, not only in middle-aged individuals but also in young individuals. However, insulin and glucose patterns have not been investigated in apparently healthy young individuals, as they are typically grouped as controls. In this study, we investigated and classified glucose and insulin patterns in healthy young women. Sixty-two nonobese women without metabolic disease were recruited. The subjects underwent a 75 g oral glucose tolerance test (OGTT), physical measurements, and a biochemical examination. Two subjects displayed impaired glucose tolerance. The 62 subjects were categorized into four patterns by plasma glucose and insulin peak time during OGTT: normal type (n = 39), insulin-late type (n = 11), insulin- and glucose-late type (n = 7), and insulin-very late type (n = 5). OGTT glucose and insulin levels at all time points, insulinogenic index, HOMA-IR, and glucose area under the curve (AUC) significantly differed among the four groups. However, insulin AUC did not significantly differ. We did not detect significant differences in body condition or biochemical measurements. Our study demonstrated that some healthy young individuals might have delayed insulin secretion by OGTT. Early detection of altered glucose metabolism might be helpful to improve lifestyle choices and prevent progression to diabetes.

Comparison of insulin lispro mix 25 with insulin lispro mix 50 as an insulin starter in Asian patients with type 2 diabetes: a phase 4, open-label, randomized trial (CLASSIFY study)

BACKGROUND

Lispro Mix 25% insulin lispro/75% insulin lispro protamine (LM25) and Lispro Mix 50% insulin lispro/50% insulin lispro protamine (LM50) were compared as starter insulins in East Asian patients with type 2 diabetes.

METHODS

Phase 4, open-label, randomized trial conducted in China, Japan, Korea, and Turkey. Subjects received twice-daily LM25 (n = 207) or LM50 (n = 196) for 26 weeks. The primary outcome was the HbA_1c change from baseline.

RESULTS

The least squares mean changes from baseline in HbA_1c are -1.52% and -1.69% for LM25 and LM50, respectively, and the least squares mean difference [95% CI] is 0.17% [-0.01, 0.35]. More subjects in the LM50 group than in the LM25 group achieved HbA_1c targets of <7.0% (59.7% versus 45.9%, respectively; p = 0.007). LM50 was more effective than LM25 in reducing postprandial glucose after the morning (mean difference in change from baseline, 0.56 mmol/L; p = 0.038) and evening (1.11 mmol/L; p < 0.001) meals. The reduction in fasting blood glucose was significantly greater (p = 0.046) in the LM25 group (LS mean [95% CI] change from baseline: -2.37 mmol/L [-2.68, -2.06]) than in the LM50 group (-1.99 mmol/L [-2.30, -1.68]). LM50 was more effective than LM25 in reducing HbA_1c in subjects with baseline HbA_1c , postprandial glucose, or carbohydrate intake levels greater than the median levels. Hypoglycemia rates and weight gain were similar between groups.

CONCLUSIONS

LM25 and LM50 were noninferior to each other in improving glycemic control in Asian patients with type 2 diabetes. In addition, LM50 was more efficacious than LM25 with respect to the percentage of subjects reaching target HbA_1c levels. Copyright © 2016 John Wiley & Sons, Ltd.

Ethnic Differences in Glucose Homeostasis Markers between the Kyushu-Okinawa Population Study and the Framingham Offspring Study

We compared markers of glucose homeostasis and their association with diabetes and impaired fasting glucose (IFG) in Fukuoka, Japanese subjects (n = 1108) and age-, gender- and menopausal status-matched participants in the Framingham Offspring Study (n = 1096). The markers examined included fasting glucose, insulin, adiponectin, and glycated albumin, as well as body mass index (BMI), use of medications, and history of diabetes. The results showed that IFG prevalence in Japanese men (15.9%) and women (7.4%) were 50% less than those observed in Framingham men (34.5%) and women (21.4%) (P < 0.001). However, the diabetes prevalence in Japanese men at 13.3% was twice as high (P < 0.01) as the rate in Framingham men at 6.5%, while these rates were similar in women. Median insulin levels in Japanese men (4.6 μIU/mL) and women (4.3 μIU/mL) were about 50% lower (P < 0.001) than those in Framingham men (10.8 μIU/mL) and women (9.9 μIU/mL), as were insulin resistance values (P < 0.001). These population differences were also observed after subjects were stratified by glucose levels. In conclusion, our data indicate that there is significantly less IFG, lower insulin levels, and insulin resistance, but higher diabetes prevalence in Fukuoka men than in Framingham men, indicating that insulin deficiency may be an important cause of diabetes in Japan.

Evaluation of insulin sensitivity and secretion in primary aldosteronism

In primary aldosteronism (PA), insulin response to glucose is not fully understood. Insulin action was elucidated using indices in 32 PA and 21 essential hypertension (EH) patients. These patients were evaluated using homeostasis model assessment (HOMA) indices, quantitative insulin sensitivity check index (QUICKI), and insulinogenic index (IGI), which were expressed for insulin sensitivity/secretion and the early phase of insulin secretion. Insulin sensitivity and early phase of insulin secretion were decreased in PA, and there was a negative correlation between serum potassium concentration and insulin sensitivity indices. These findings suggest that glucose intolerance in PA may be caused by hypokalemia-induced insulin resistance and hypokalemia-independent impairment of early-phase insulin secretion.

Duration of diabetes and types of diabetes therapy in Japanese patients with type 2 diabetes: The Japan Diabetes Complication and its Prevention prospective study 3 (JDCP study 3)

Aims/Introduction

To analyze the association between the duration of diabetes and selection of diabetes therapy in a large database of Japanese patients with type 2 diabetes.

Materials and Methods

We used the data of 5,844 patients with type 2 diabetes to evaluate the association between the duration of diabetes and types of diabetes therapy. The logistic regression model was used to analyze the association between duration of diabetes and selection of diabetes therapy, and restricted cubic spline curves were used to represent the schematic association.

Results

Overall, clinical characteristics of the patients were women, 39.9%; mean age, 61.4 years; median duration of diabetes, 9 years; mean glycated hemoglobin, 7.4% (57.0 mmol/mol); and mean body mass index, 24.5 kg/m². Compared with the first quartile of diabetes duration, the multivariable‐adjusted odds of any antidiabetic therapy (oral hypoglycemic agents or insulin) for the second, third and fourth quartiles were 2.17 (95% confidence interval [CI] 1.68–2.80; 3.39, 95% CI 2.53–4.54; 4.99, 95% CI 3.64–6.84), respectively (P for trend <0.001), and these associations were attenuated after adjusting possible confounders. Furthermore, those of insulin therapy were 1.48 (95% CI 1.20–1.84; 2.16, 95% CI 1.77–2.64; 4.94, 95% CI 4.04–6.04), respectively (P for trend <0.001). Schematic representation of restricted cubic spline curves analysis showed that a longer duration of diabetes was linearly associated with the odds of insulin therapy.

Conclusions

Obtained data showed that a longer duration of diabetes required complex diabetes drug regimens to be introduced to patients with type 2 diabetes.

Clinical characteristics and beta cell function in Chinese patients with newly diagnosed type 2 diabetes mellitus with different levels of serum triglyceride

BACKGROUND

To explore clinical characteristics and beta cell function in Chinese patients with newly diagnosed drug naive type 2 diabetes mellitus (T2DM) with different levels of serum triglyceride (TG).

METHODS

Patients with newly diagnosed T2DM (n = 624) were enrolled and divided into different groups according to levels of serum TG. All patients underwent oral glucose tolerance tests and insulin releasing tests. Demographic data, lipid profiles, glucose levels, and insulin profiles were compared between different groups. Basic insulin secretion function index (homeostasis model assessment for beta cell function index, HOMA-β), modified beta cell function index (MBCI), glucose disposition indices (DI), and early insulin secretion function index (insulinogenic index, IGI) were used to evaluate the beta cell function.

RESULTS

Patients of newly diagnosed T2DM with hypertriglyceridemia were younger, fatter and had worse lipid profiles, glucose profiles, and high insulin levels than those with normal TG. There is no difference in early phase insulin secretion among groups of newly diagnosed T2DM patients with different TG levels. The basal beta cell function (HOMA-β and MBCI) initially increased along rising TG levels and then decreased as the TG levels rose further. The insulin sensitivity was relatively high in patients with a low level of TG and low with a high level of TG.

CONCLUSIONS

Hypertriglyceridemia influences clinical characteristics and β cell function of Chinese patients with newly diagnosed T2DM. A better management of dyslipidemia may, to some extent, reduce the effect of lipotoxicity, thereby improving glucose homeostasis in patients with newly diagnosed T2DM.

Update on diabetes classification

This article highlights the difficulties in creating a definitive classification of diabetes mellitus in the absence of a complete understanding of the pathogenesis of the major forms. This brief review shows the evolving nature of the classification of diabetes mellitus. No classification scheme is ideal, and all have some overlap and inconsistencies. The only diabetes in which it is possible to accurately diagnose by DNA sequencing, monogenic diabetes, remains undiagnosed in more than 90% of the individuals who have diabetes caused by one of the known gene mutations. The point of classification, or taxonomy, of disease, should be to give insight into both pathogenesis and treatment. It remains a source of frustration that all schemes of diabetes mellitus continue to fall short of this goal.

Identification of putative biomarkers for prediabetes by metabolome analysis of rat models of type 2 diabetes

Biomarkers for the development of type 2 diabetes (T2D) are useful for prediction and intervention of the disease at earlier stages. In this study, we performed a longitudinal study of changes in metabolites using an animal model of T2D, the spontaneously diabetic Torii (SDT) rat. Fasting plasma samples of SDT and control Sprague-Dawley (SD) rats were collected from 6 to 24 weeks of age, and subjected to gas chromatography-mass spectrometry-based metabolome analysis. Fifty-nine hydrophilic metabolites were detected in plasma samples, including amino acids, carbohydrates, sugars and organic acids. At 12 weeks of age, just before the onset of diabetes in SDT rats, the amounts of nine of these metabolites (asparagine, glutamine, glycerol, kynurenine, mannose, n-alpha-acetyllysine, taurine, threonine, and tryptophan) in SDT rats were significantly different from those in SD rats. In particular, metabolites in the tryptophan metabolism pathway (tryptophan and kynurenine) were decreased in SDT rats at 12 weeks of age and later. The lower tryptophan and kynurenine levels in the prediabetic state and later were further confirmed by a replication study on SDT rats and by a longitudinal study on another animal model of T2D, the Otsuka Long-Evans Tokushima Fatty rat. Our data indicate that tryptophan and its metabolites are potential biomarkers for prediabetes and that tryptophan metabolism may be a potential target of intervention for treatment of the disease.

Insulin secretory capacity and insulin sensitivity in impaired fasting glucose in Japanese

Aims/Introduction:  Impaired fasting glucose (IFG) increases the risk of developing diabetes mellitus (DM). This study was carried out to characterize Japanese patients who have fasting glucose levels (FPG) between 100 and 109 mg/dL (IFG_100–109).

Materials and Methods:  A total of 1383 Japanese participants were examined by oral glucose tolerance test. We compared insulin secretory capacity (insulinogenic index) and insulin sensitivity (ISI composite) of IFG_100–109/normal glucose tolerance (NGT; 100 ≤ FPG < 110 mg/dL and 2‐h postchallenge glucose level (2‐hPG) < 140 mg/dL) with NGT (100 mg/dL < FPG and 2‐hPG < 140 mg/dL) and IFG_110–125/NGT (110 ≤ FPG < 126 mg/dL and 2‐hPG < 140 mg/dL). In addition, IFG_100–109 patients were analyzed in three subgroups according to glucose intolerance by 2‐hPG.

Results:  Of the three categories of IFG_100–109, IFG_100–109/DM had the lowest insulinogenic index despite an ISI composite showing only a small decline from IFG_100–109/NGT through IFG_100–109/IGT (100 ≤ FPG < 110 mg/dL and 140 ≤ 2‐hPG < 200 mg/dL) to IFG_100–109/DM (100 ≤ FPG < 110 mg/dL and 200 mg/dL < 2‐hPG). By multiple regression analysis, the insulinogenic index showed a significant relationship with 2‐h PG levels. Both insulinogenic index and ISI composite were decreased significantly from NGT through IFG_100–109/NGT to IFG_110–125/NGT.

Conclusions:  Although impaired early‐phase insulin secretion plays the more important role in the elevation of postchallenge glucose in IFG_100–109 patients, both impaired early‐phase insulin secretion and decreased insulin sensitivity are involved in the deterioration of FPG in Japanese. In addition, insulin secretory defect and decreased insulin sensitivity already have begun in patients with IFG_100–109.(J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00201.x, 2012)

Plasma gastric inhibitory polypeptide and glucagon-like peptide-1 levels after glucose loading are associated with different factors in Japanese subjects

Aims/Introduction:  Gastric inhibitory polypeptide (GIP) and glucagon‐like peptide‐1 (GLP‐1) are major incretins that potentiate insulin secretion from pancreatic β‐cells. The factors responsible for incretin secretion have been reported in Caucasian subjects, but have not been thoroughly evaluated in Japanese subjects. We evaluated the factors associated with incretin secretion during oral glucose tolerance test (OGTT) in Japanese subjects with normal glucose tolerance (NGT).

Materials and Methods:  We measured plasma GIP and GLP‐1 levels during OGTT in 17 Japanese NGT subjects and evaluated the factors associated with GIP and GLP‐1 secretion using simple and multiple regression analyses.

Results:  GIP secretion (AUC‐GIP) was positively associated with body mass index (P < 0.05), and area under the curve (AUC) of C‐peptide (P < 0.05) and glucagon (P < 0.01), whereas GLP‐1 secretion (AUC‐GLP‐1) was negatively associated with AUC of plasma glucose (P < 0.05). The insulinogenic index was most strongly associated with GIP secretion (P < 0.05); homeostasis model assessment β‐cell was the most the strongly associated factor in GLP‐1 secretion (P < 0.05) among the four indices of insulin secretion and insulin sensitivity.

Conclusions:  Several distinct factors might be associated with GIP and GLP‐1 secretion during OGTT in Japanese subjects. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00078.x, 2011)

Efficacy and safety of patient-directed titration of once-daily pre-dinner premixed biphasic insulin aspart 70/30 injection in Japanese type 2 diabetic patients with oral antidiabetic drug failure: STEP-AKITA study

Aims/Introduction:  To clarify clinical characteristics related to optimal glycemic control achieved after adding once‐daily pre‐dinner biphasic insulin aspart 70/30 (BIAsp 30) in Japanese type 2 diabetic (T2D) patients with oral antidiabetic drug (OAD) failure.

Materials and Methods:  Under this regimen, we evaluated changes in HbA_1c levels and daily self‐monitoring blood glucose (BG) profiles, as well as the incidences of hypoglycemia and retinopathy progression. The patients adjusted BIAsp 30 dosages themselves every 3–4 days according to a pre‐determined algorithm to achieve fasting BG levels of 101–120 mg/dL. HbA_1c levels were expressed as Japan Diabetes Society values.

Results:  Of 29 enrolled patients, 22 (HbA_1c levels, 8.5 ± 1.5% [mean ± SD]) and 20 patients completed the 16‐ and 24‐week follow‐up, respectively. At 16 weeks 68.2 and 45.5%, and at 24 weeks 80.0 and 35% of patients had achieved HbA_1c levels of <7.0 and <6.5%, respectively. The patients who had achieved optimal glycemic control, including daytime postprandial BG profiles after treatment, had lower post‐breakfast BG excursions at baseline, shorter diabetes durations and younger age. No severe hypoglycemic episodes were recorded. Progression of retinopathy was observed in 3 of the 29 enrolled patients.

Conclusions:  Lower post‐breakfast BG excursions, shorter diabetes duration and younger age in Japanese T2D patients with OAD failure might warrant optimal glycemic control with safety after adding once‐daily pre‐dinner BIAsp 30 initiating regimen. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00062.x, 2010)

Relationship and factors responsible for regulating fasting and post-challenge plasma glucose levels in the early stage development of type 2 diabetes mellitus

AIMS/INTRODUCTION

Elevation of 2-h plasma glucose (2-h PG) levels keeps step with fasting plasma glucose (FPG) levels elevation, but some individuals show dominant elevation of 2-h PG and others FPG. We analyzed dependent and independent relationships between 2-h PG and FPG, and investigated the factors regulating 2-h PG and FPG.

MATERIALS AND METHODS

In 1,657 Japanese participants who underwent a 75-g oral glucose tolerance test at the initial examination for a medical check-up, we carried out simple linear regression analysis between 2-h PG and FPG levels on the three patterns of independent variables. We divided the participants into two subgroups: the 2-h PG-side group and the FPG-side from the regression line, and examined the relationships between 2-h PG-FPG and factors responsible for elevation of plasma glucose levels.

RESULTS

There was a significant positive correlation between 2-h PG and FPG levels. The regression line of both 2-h PG and FPG as independent variables was in accordance with the regression line of 2-h PG as an independent variable and FPG as a dependent variable. In 2-h PG-side group, age was the independent factor affecting 2-h PG in addition to insulinogenic index and insulin sensitivity index (ISI composite). In the FPG-side group, triglyceride was the independent factor affecting FPG in addition to insulinogenic index and ISI composite.

CONCLUSIONS

Two-hour PG was an independent predictor of FPG. In addition to the importance of decreased insulin secretion and insulin sensitivity, age was the strong factor to elevate 2-h PG levels in the 2-h PG-side group and triglyceride was the strong factor to elevate FPG levels in the FPG-side group in the early stage of development of type 2 diabetes.

The relationship between coronary risk factors and elevated 1-h postload plasma glucose levels in patients with established coronary heart disease

OBJECTIVE

Recent studies have shown that an elevated 1-h postload plasma glucose (1hPG) is able to identify subjects with normal glucose tolerance (NGT) at high risk for future type 2 diabetes and atherosclerotic cardiovascular disease. However, clinical studies about the characteristics of coronary heart disease (CHD) patients with elevated 1hPG are lacking. The aim of this study was to analyse the 1hPG level in CHD patients with NGT.

METHODS

A total of 204 CHD patients with NGT were recruited. Subjects underwent an oral glucose tolerance test, echocardiography and coronary angiography. Demographic data were recorded and blood samples obtained. According to the 1hPG cut-off point of 8.6 mm, patients were divided into two groups: 1hPG ≥ 8.6 mm (n = 65) and 1hPG < 8.6 mm (n = 139).

RESULTS

Compared with the 1hPG < 8.6 mm group, subjects with 1hPG ≥ 8.6 mm had a worse metabolic profile, exhibiting significantly higher body mass index, systolic blood pressure, triglyceride level and lower HDL-cholesterol level. Plasma high-sensitivity CRP (hsCRP) levels were higher in the 1hPG ≥ 8.6 mm group than in the 1hPG < 8.6 mm group. Coronary angiography revealed that single-vessel changes were more frequent in the 1hPG < 8.6 mm group, but there were no significant differences in the Gensini score.

CONCLUSIONS

Patients with CHD with 1hPG ≥ 8.6 mm have a worse metabolic profile, higher levels of hsCRP and multi-vessel coronary atherosclerosis. These findings suggest that, in patients with CHD, elevated 1hPG increases coronary risk factors and may be a marker for early-stage glucose intolerance.

Prevention of diabetes: a strategic approach for individual patients

The 'diabetes epidemic' is an important health and socioeconomic problem worldwide. Type 2 diabetes is a chronic disease with gradual deterioration in glucose metabolism which causes multiple systemic complications. Therefore, early intervention in the prediabetic stage is a valuable approach to reduce diabetes development and related complications. Many clinical trials have suggested that lifestyle intervention, including moderate-intensity exercise and diet control, and pharmacologic intervention using metformin, α-glucosidase inhibitors, thiazolidinediones, anti-obesity drugs and incretin mimics, are effective in preventing diabetes development. However, an individualized approach with careful consideration of the patient's risk status and health economics is needed to perform a successful intervention programmes. In this review, we will summarize the known evidence on treatment- and cost-effectiveness of drug and lifestyle treatment. Additionally, we will propose a strategic approach algorithm that is applicable to clinical practice.

Comparison of efficacy of concomitant administration of mitiglinide with voglibose and double dose of mitiglinide in patients with type 2 diabetes mellitus

Aims/Introduction:  When monotherapy with an oral hypoglycemic agent (OHA) is not sufficiently effective for blood glucose control, combination therapy with OHA having different mechanisms of action might be indicated.

MATERIALS AND METHODS

  In the present study, we compared the efficacy of two options in type 2 diabetes mellitus patients whose blood glucose had not been well controlled with mitiglinide (30 mg/day) alone. A total of 20 patients were included in the study and divided into two groups: group A, in which mitiglinide was given concomitantly with the α-glucosidase inhibitor voglibose (0.6 mg/day); and group B, in which a double dose of mitiglinide was given (60 mg/day). Twelve weeks after changing the medication, HbA1c, glycoalbumin and 1,5-anhydroglucitol (1,5-AG) were measured. In addition, at weeks 0 and 12, a meal tolerance test was carried out, and plasma glucose, insulin, glucagon, active glucagon-like peptide-1 (GLP-1) and total glucose-dependent insulinotropic polypeptide levels were measured.

RESULTS

  The plasma level of 1,5-AG improved in both groups at week 12. In group A, the plasma insulin level significantly decreased and the plasma active GLP-1 level significantly increased during the meal tolerance test at week 12; thus, bodyweight significantly decreased only in group A.

CONCLUSIONS

  Our findings suggested that concomitant administration of mitiglinide with voglibose could achieve better glycemic control, particularly in the postprandial period, without bodyweight gain and might have beneficial effects in type 2 diabetic patients at risk of macrovascular complications. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.0082.x, 2011).

Addressing the burden of type 2 diabetes and cardiovascular disease through the management of postprandial hyperglycaemia: an Asian-Pacific perspective and expert recommendations

The world is facing an epidemic of cardiovascular disease (CVD) and type 2 diabetes, with populations in low- to middle-income countries, including many in the Asia Pacific (AP) region, being disproportionately affected. Emerging data identify postprandial hyperglycaemia (PPHG) as an important predictor of CVD, and several professional bodies, including the International Diabetes Federation, have issued guidelines on the management of PPHG in type 2 diabetes. Guidance on how international recommendations could be implemented in Asian populations is currently lacking. Therefore, a panel of experts from the AP region convened to consider the current status of PPHG and CVD in the region, and to develop recommendations for clinical practice. The group concluded that improved awareness of the impact of PPHG on CVD risk, among clinicians and the general public, and more widespread use of routine screening for PPHG, using oral glucose tolerance testing in those without recognised diabetes, are required. Additionally, frequent meal-based testing and effective PPHG management are essential to the management of IGT and type 2 diabetes.

Insulin tolerance test predicts the effectiveness of insulin sensitizers in japanese type 2 diabetic patients

INTRODUCTION

The purpose of this study was to assess the efficacy of the insulin tolerance test (ITT) in predicting the effectiveness of insulin sensitizers in type 2 diabetic patients.

METHODS

We retrospectively reviewed 360 consecutive patients with type 2 diabetes admitted to Osaka University Hospital, Japan. In 163 of these hospitalized patients, insulin resistance was evaluated by the ITT after their blood glucose level was ameliorated. We then analyzed the association between their clinical characteristics and their glycemic control 6 months after discharge.

RESULTS

The rate constant for plasma glucose disappearance, K (ITT), was negatively correlated with body mass index (BMI), waist circumference (WC), and visceral fat area (VFA). The median value of K (ITT) was 1.56 (%/min). In the K (ITT) > 1.56 group (n=81), hemoglobin A(1c) (HbA(1c)) significantly increased in both patients treated with insulin sensitizers (n=10) and patients not treated with insulin sensitizers (n=71). In the K (ITT) ≤1.56 group (n=82), HbA(1c) significantly increased in patients not treated with insulin sensitizers (n=60); however, it was maintained well in the patients treated with insulin sensitizers (n=22). When the patients were divided and analyzed according to the median values of BMI, WC, or VFA, the glycemic control change was not different between the two groups with insulin sensitizers for each parameter.

CONCLUSION

Insulin sensitizers were effective in type 2 diabetic patients with high insulin resistance estimated by the ITT. The ITT could be useful to predict the effectiveness of insulin sensitizers.

Early insulin secretion failure leads to diabetes in Chinese subjects with impaired glucose regulation

BACKGROUND

Both beta-cell dysfunction and decreased insulin sensitivity are involved in the pathogenesis of impaired glucose tolerance (IGT) and impaired fasting glucose (IFG), while their relative contribution in the progression to type 2 diabetes still remains controversial. The aim of the present study is to clarify this process in Chinese subjects by using cross-sectional method.

METHODS

2,975 Chinese subjects were classified into: normal glucose tolerance (NGT), impaired glucose regulations (IGR), and diabetes mellitus (DM) based on oral glucose tolerance test (OGTT). The IGR group was sub-classified as isolated IFG, isolated IGT and combined glucose intolerance (CGI). The DM group was sub-classified as normal fasting plasma glucose and 2-hour hyperglycemia (N0D2), fasting hyperglycemia and normal 2-hour plasma glucose (D0N2), and both fasting and 2-hour hyperglycemia (D0D2).

RESULTS

As far as insulinogenic index (IGI) was concerned, there was no difference between IFG and IGT in either gender, however, HOMA2-B% (homeostasis model assessment for beta-cell function) of IGT was higher than that of IFG and CGI in both male and female (P < 0.05). In the diabetic sub-groups, IGI of N0D2 was higher than that of D0N2, and both deteriorated compared with those of IGT and IFG, respectively. HOMA2-B% of N0D2 was still higher than that of D0N2 and D0D2. No significant difference was detected in OGIS and HOMA2-S% (homeostasis model assessment for insulin sensitivity) between IFG and IGT, and this was the case between N0D2 and D0N2. OGIS and HOMA-IR of IGR sub-groups were not different from those of their diabetic counterparts.

CONCLUSION

Failure of beta-cell function might be the main reason for both IGT and IFG developing into diabetes instead of aggravated insulin resistance.

Efficacy and safety of exenatide in patients of Asian descent with type 2 diabetes inadequately controlled with metformin or metformin and a sulphonylurea

AIMS

To evaluate the efficacy of exenatide in Asian patients with type 2 diabetes (T2D) inadequately controlled with oral agents.

METHODS

Patients taking metformin (MET) alone or with a sulphonylurea (SU) were randomly assigned to exenatide 5 microg then 10 microg twice-daily for 4 and 12 weeks, respectively, or placebo. The primary endpoint was baseline to endpoint HbA(1c) change.

RESULTS

466 patients (age 54+/-9 years, weight 68.7+/-11.2 kg, BMI 26.3+/-3.3 kg/m(2), and HbA(1c) 8.3+/-1.1%; mean+/-S.D.) were enrolled in the full analysis set. Endpoint HbA(1c) reduction (mean [95% CI]) with exenatide was superior to placebo (-1.2 [-1.3, -1.1]% vs. -0.4 [-0.5, -0.2]%, p<0.001). More exenatide- than placebo-treated patients achieved HbA(1c) <or=7% (48% vs. 17%, p<0.001). At endpoint, weight reduction was greater with exenatide (-1.2 [-1.5, -0.9]kg) than placebo (-0.1 [-0.3, 0.2]kg), p<0.001. Nausea, generally mild-to-moderate, was the most common adverse event with exenatide (25% vs. 1% with placebo). The incidence of symptomatic hypoglycaemia with exenatide and placebo were 36% and 9%, respectively (p<0.001). Hypoglycaemia rates (events/patient-year) for patients taking exenatide with MET or MET and SU were 1.8 (0.9, 3.7) and 4.7 (3.5, 6.5), respectively.

CONCLUSION

Exenatide treatment improved glycaemic control in Asian patients with T2D and had a similar safety profile as in non-Asian patients.

Metabolic characteristics of subjects with normal glucose tolerance and 1-h hyperglycaemia

OBJECTIVE

Nondiabetic subjects with a 1-h plasma glucose >or= 11.1 mmol/l during an oral glucose tolerance test (OGTT) drew our attention to their somewhat confusing status and relative frequency among Chinese patients. The aim of this study was to clarify the metabolic characteristics of these subjects.

DESIGN AND PATIENTS

A total of 2549 Chinese subjects were included in this study. Based on results of OGTT, these subjects were classified into three groups: normal glucose tolerance (NGT), impaired glucose regulation (IGR) and diabetes mellitus (DM). Then, according to the level of 1-h plasma glucose, the NGT and IGR groups were subclassified, respectively, as: NGT without 1-h hyperglycaemia (NGTN), NGT with hyperglycaemia at 1 h (NGT1H), IGR without 1-h hyperglycaemia (IGRN), and IGR with hyperglycaemia at 1 h (IGR1H).

RESULTS

After adjustments for age and gender, the insulinogenic index (IGI) of NGT1H and IGR1H was found to be lower than for those with NGTN and of IGRN, respectively (P < 0.05). No statistical differences, however, were found in oral glucose insulin sensitivity (OGIS) between either of the 1-h hyperglycaemic groups or of the corresponding NGTN or IGRN groups. Homeostasis model assessment for beta-cell function (HOMA-B) of NGT1H was lower than that of NGTN (P < 0.05), while IGRN and IGR1H showed no difference. No differences in homeostasis model assessment for insulin resistance (HOMA-IR) were found among NGTN, NGT1H, IGRN and IGR1H groups. The levels of triglycerides (TG) were not significantly different among NGT1H, IGRN and IGR1H, while TG in these groups were significantly higher than in NGTN (P < 0.05). LDL-C was significantly higher and HDL significantly lower in NGT1H than in all other groups (P < 0.05).The IGR group was also subclassified as: isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT) and combined glucose intolerance (CGI). The IGI of the NGT1H group was similar to the IGI that of combined glucose intolerance group but lower than those of IFG and IGT (P < 0.05).The OGIS of the NGT1H group was the highest among all groups (P < 0.05). HOMA-B of IGT and NGT1H were higher than that of IFG (P < 0.05). There was no difference among all groups in HOMA-IR. Plasma lipid levels were not significantly different between NGT1H and any other group.

CONCLUSIONS

Chinese NGT subjects with a 1-h plasma glucose >/= 11.1 mmol/l are characterized by metabolic abnormalities, which may be caused by the impairment of early insulin release rather than aggravated insulin resistance.

Factors responsible for elevation of 1-h postchallenge plasma glucose levels in Japanese men

The 1-h postchallenge plasma glucose (1-h PG) level is considered to be a good index of the development of glucose intolerance and type 2 diabetes as well as of diabetic complications. In some cases, in Japanese, 1-h PG is elevated despite normal fasting glucose during oral glucose tolerance test (OGTT), but the factors responsible remain unclear. In the present study, subjects with normal glucose tolerance (NGT), isolated impaired fasting glucose (IFG), and isolated impaired glucose tolerance (IGT) were divided into subgroups at 1-h PG of 10.0mM, and the four indices of insulin secretion and insulin sensitivity were compared. In all three categories, the insulinogenic index in subjects with elevated 1-h PG was remarkably lower than in those without elevated 1-h PG. In addition, the insulinogenic index was the strongest factor in elevated 1-h PG according to the multiple regression analysis. Interestingly, one third of the NGT subjects enrolled in this study had elevated 1-h PG. These subjects showed significantly elevated area under the curve of glucose (G-AUC) compared to NGT subjects without 1-h PG elevation. Thus, elevated 1-h PG in Japanese subjects indicates mildly impaired glucose tolerance due to decreased early-phase insulin secretion.

Factors responsible for age-related elevation in fasting plasma glucose: a cross-sectional study in Japanese men

To evaluate the factors associated with age-related increase in fasting plasma glucose (FPG) in Japanese men with normal fasting glucose, we measured FPG, fasting immunoreactive insulin, glycated hemoglobin, total cholesterol, triglyceride, and high-density lipoprotein cholesterol levels in health check examinees. Subjects with FPG less than 6.1 mmol/L together with glycated hemoglobin less than 5.6% were enrolled in the study. The homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA-beta were used as the indices of insulin sensitivity and insulin secretion, respectively. Fasting plasma glucose increased significantly with age (r = 0.30, P < .0001), and HOMA-beta decreased significantly with age (r = 0.24, P < .0001). The HOMA-IR had no significant relation with age (r = 0.06, not significant), whereas body mass index and serum triglyceride were associated with HOMA-IR (r = 0.49, P < .0001 and r = 0.33, P < .0001, respectively). Thus, in Japanese male subjects with normal fasting glucose, it is suggested that the FPG increment with age is associated with decreased beta-cell function rather than with insulin resistance. Further analyses were performed by comparing 3 groups: low FPG (FPG <5.0 mmol/L), high FPG (5.0 < or = FPG < 5.6 mmol/L), and mild impairment of fasting glycemia (mild IFG) (5.6 < or = FPG < 6.1 mmol/L). The insulin levels in mild IFG and high FPG were significantly higher than in low FPG (P < .001), but those in mild IFG were similar to those in high FPG. Analysis of the 3 subgroups revealed that, whereas insulin sensitivity was impaired more in high FPG, there was little compensatory increase in insulin in mild IFG, suggesting that beta-cell function is already deteriorated when the FPG level is greater than 5.6 mmol/L.