Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Transcription factor EB influences invasion and migration in oral squamous cell carcinomas

OBJECTIVE

Transcription factor EB (TFEB) is a master regulator of lysosomal biogenesis and plays an important role in various cancers. However, the function of TFEB in oral squamous cell carcinomas has not been examined. The aim of this study was to elucidate the role of TFEB in oral squamous cell carcinomas.

MATERIALS AND METHODS

Expression levels of TFEB were examined in six different human oral squamous carcinoma cells: HSC2, HSC3, HSC4, SAS, OSC20, and SCC25. Knockdown of TFEB using small interfering RNA in HSC2 and HSC4 cells was performed. Cell morphology was observed by immunofluorescence microscopy. Cell proliferation, invasion, and adhesion were analyzed.

RESULTS

Expression levels of TFEB were high in HSC2, moderate in HSC4 and SCC25, and low in HSC3 and OSC20 cells. Knockdown of TFEB did not affect proliferation of HSC2 and HSC4 cells, but did induced enlargement of lysosomes and endosomes in HSC4 cells. TFEB silencing reduced invasion and migration of these HSC cell squamous carcinoma cells; however, increased cell adhesion was also observed.

CONCLUSION

TFEB knockdown reduces invasion and migration of cancer cells, likely through lysosomal regulation. Taken together, TFEB influences cell invasion and migration of oral squamous cell carcinomas.

A case of insulin allergy successfully managed using multihexamer-forming insulin degludec combined with liraglutide

BACKGROUND

Insulin allergy, one of insulin's adverse effects, is rare, especially in patients with Type 2 diabetes, but management is difficult and no effective strategy has yet been established. We experienced an insulin allergy case successfully managed with a novel combination of insulins.

CASE REPORT

A 38-year-old woman started insulin therapy when diabetes was diagnosed at age 19 years. Despite poorly controlled diabetes because of poor adherence, she hoped to conceive a child and continuous subcutaneous insulin infusion was introduced using insulin aspart at age 32 years. One month thereafter, she developed skin reactions at the subcutaneous insulin infusion catheter insertion site. The patient was then tested for all rapid-acting insulin formulations, all of which triggered local reactions. She decided to continue the continuous subcutaneous infusion of human regular insulin, accompanied by oral cetirizine hydrochloride and betamethasone valerate ointment. The patient was admitted to our hospital at age 38 years with high HbA_1c levels. She was tested for all long-acting insulin analogues. All results, except for insulin degludec, were positive. She discontinued continuous subcutaneous insulin infusion and switched to insulin degludec combined with liraglutide. The allergic reactions had completely disappeared and her blood glucose was well controlled by the time of discharge.

CONCLUSION

Our patient was allergic to all insulin formulations except insulin degludec. Her allergic reactions completely disappeared after switching to insulin degludec. The crystallized structure of this insulin might mask its skin allergen antigenicity. Furthermore, her postprandial hyperglycaemia was successfully controlled with liraglutide. We propose multihexamer-forming ultra-long-acting insulin plus glucagon-like peptide-1 analogues as a therapeutic option for patients with insulin allergy.

Sitagliptin improves glycaemic excursion after a meal or after an oral glucose load in Japanese subjects with impaired glucose tolerance

AIMS

To evaluate the efficacy and tolerability of sitagliptin in subjects with impaired glucose tolerance (IGT).

METHODS

In a double-blind, parallel-group study, 242 Japanese subjects with IGT, determined by a 75-g oral glucose tolerance test (OGTT) at week -1, were randomized (1 : 1 : 1) to placebo (n = 83), sitagliptin 25 mg (n = 82) or 50 mg (n = 77) once daily for 8 weeks. Glycaemic variables were assessed using another OGTT at week 7 and meal tolerance tests (MTTs) at weeks 0 and 8. Primary and secondary endpoints were percent change from baseline in glucose total area under the curve 0-2 h (AUC(0 -2 h)) during the MTT and OGTT, respectively.

RESULTS

Least squares mean percent change from baseline in glucose AUC(0 -2 h) during the MTT were -2.4, -9.5 and -11.5%, and during the OGTT were -3.7, -21.4 and -20.1% with placebo, sitagliptin 25 mg once daily, and 50 mg once daily, respectively (p < 0.001 for either sitagliptin dose vs placebo in both tests). Sitagliptin treatment enhanced early insulin response during the OGTT and decreased total insulin response, assessed as the total AUC(0 -2 h) during the MTT. Sitagliptin treatment also suppressed glucagon response during the MTT. The incidence of adverse events, including hypoglycaemia, was low and generally similar in all treatment groups.

CONCLUSIONS

Treatment with sitagliptin significantly reduced glucose excursions during both an MTT and an OGTT; this effect was associated with an increase in early insulin secretion after oral glucose loading as well as a blunted glucagon response during an MTT. Sitagliptin was generally well tolerated in subjects with IGT.

A novel and selective sodium-glucose cotransporter-2 inhibitor, tofogliflozin, improves glycaemic control and lowers body weight in patients with type 2 diabetes mellitus

AIM

To assess the efficacy, safety and tolerability of different doses of tofogliflozin, a novel, highly selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes mellitus (T2DM).

METHODS

In a 12-week, multicentre, multinational, randomized, double-blind, parallel-group, placebo-controlled, dose-finding study, patients with inadequate glycaemic control from diet and exercise alone, or from diet and exercise plus a stable dose of metformin, were randomized to one of five doses of tofogliflozin (2.5, 5, 10, 20, or 40 mg) or placebo. The primary efficacy endpoint was absolute change at week 12 from baseline in glycated haemoglobin (HbA1c), minus the change in the placebo group.

RESULTS

Statistically significant dose-dependent reductions in HbA1c were shown in all treated groups except the 2.5-mg dose group, with a maximum reduction of 0.56% (placebo-subtracted) at the 40-mg dose, along with increased urinary glucose excretion. Metformin treatment had no substantial influence on tofogliflozin efficacy. Dose-dependent reductions in fasting plasma glucose and body weight were observed, and glucose intolerance was improved, with a trend towards blood pressure reduction. Slight increases were observed for mean ketone bodies with no abnormal change in ketone body ratio. No deaths or treatment-related serious adverse events were reported. The incidence of adverse events was similar in the placebo (37.9%) to that in the tofogliflozin group (35.9-46.3%). Withdrawal because of adverse events was rare (≤2 patients per treatment group), with similar rates of withdrawal in the placebo and tofogliflozin groups.

CONCLUSIONS

A once-daily dose of tofogliflozin for 12 weeks was an effective, safe and well-tolerated treatment for T2DM.

Evaluation of cutoff scores for the Parkinson's disease sleep scale-2

BACKGROUND

The Parkinson's Disease Sleep Scale (PDSS)-2 is a recently developed tool for evaluating disease-related nocturnal disturbances in patients with Parkinson's disease (PD). However, its cutoff score has not been clinically assessed. We determined the optimal cutoff score of the Japanese version of the PDSS-2.

METHODS

Patients with PD (n = 146) and controls (n = 100) completed the PDSS-2 and the Pittsburgh Sleep Quality Index (PSQI). Poor sleepers were defined as having global PSQI scores >5. Optimal cutoff scores for determining poor sleepers were assessed using the receiver operating characteristic curve.

RESULTS

A PDSS-2 total score ≥ 14 exhibited 82.0% sensitivity and 70.6% specificity, whereas a PDSS-2 total score ≥ 15 provided 72.1% sensitivity and 72.9% specificity in distinguishing poor sleepers (PSQI score >5) from good sleepers (PSQI ≤ 5). Nocturnal disturbances were more frequently observed in patients with PD than in controls (PDSS-2 total score ≥ 14 or ≥ 15; 51.4% vs 20%; 45.9% vs 19%). Nocturnal disturbances were associated with higher Hoehn and Yahr stages and Unified Parkinson's Disease Rating Scale motor scores, impaired quality of life, daytime sleepiness, and depressive symptoms.

CONCLUSION

We suggest that PDSS-2 total scores ≥ 15 are useful for detecting poor sleepers among patients with PD.

Efficacy and safety of teneligliptin added to glimepiride in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled study with an open-label, long-term extension

AIMS

To assess the efficacy and safety of teneligliptin in combination with glimepiride in Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with glimepiride monotherapy.

METHODS

In the initial 12-week, double-blind, placebo-controlled, parallel-group period, 194 patients [haemoglobin A1c (HbA1c): 8.4 ± 0.8%; fasting plasma glucose (FPG): 164.2 ± 28.1 mg/dl] were randomized to either teneligliptin 20 mg or placebo once daily while continuing stable glimepiride therapy. This randomized period was then followed by a 40-week, open-label period, where all patients received teneligliptin once daily. The primary endpoint was the change in HbA1c from baseline to week 12.

RESULTS

Teneligliptin reduced HbA1c significantly compared with placebo at week 12. The placebo-subtracted change in HbA1c was -1.0 ± 0.1% [least-squares (LS) mean ± s.e., p < 0.001]. Teneligliptin also significantly reduced FPG and 2-h postprandial glucose (PPG) as compared with placebo at week 12; the placebo-subtracted changes were -27.1 ± 3.2 and -49.1 ± 6.2 mg/dl (LS mean ± s.e., both p < 0.001), respectively. The blood glucose-lowering effects were sustained throughout the 40-week open-label period. The incidence rates of adverse events and adverse drug reactions, including hypoglycaemia, during the double-blind randomized period were similar in both groups. Therefore, teneligliptin was generally well tolerated when used in combination with glimepiride.

CONCLUSIONS

The addition of teneligliptin was effective and generally well tolerated in Japanese patients with T2DM inadequately controlled with glimepiride monotherapy. The improvements in glycaemic control were maintained for up to 52 weeks.

Teneligliptin for the treatment of type 2 diabetes

Teneligliptin, characterized by a "J-shaped" structure formed by five consecutive rings, is a novel dipeptidyl peptidase 4 (DPP IV) inhibitor for the treatment of type 2 diabetes. Teneligliptin is eliminated via excretion with a half-life of 24.2 hours in human plasma from the kidney and metabolism involving certain enzymes. Hence, dose adjustment is not required in patients with renal impairment. A pharmacokinetic/pharmacodynamic study revealed that teneligliptin inhibits DPP IV activity over 24 hours, with elevation of activated glucagon-like peptide 1 (GLP-1) levels and the resulting suppression of postprandial hyperglycemia at all three daily meals. Monotherapy for 12 weeks significantly decreased hemoglobin A1c (HbA1c), fasting blood glucose, and 2-hour postprandial blood glucose levels in patients with type 2 diabetes. The therapeutic efficacy of teneligliptin over 52 weeks was confirmed not only as monotherapy but also as add-on therapy in patients with inadequately controlled blood glucose levels with sulfonylureas or thiazolidinediones. The incidence of adverse drug reactions was approximately 10% in all clinical studies of patients with type 2 diabetes conducted in Japan. The incidence of hypoglycemia was comparable in patients receiving teneligliptin or placebo, and no serious hypoglycemia was observed. Thus, teneligliptin is a novel antihyperglycemic agent with a preferable profile in terms of long-term efficacy and safety in patients with type 2 diabetes.

Efficacy, safety and dose-response relationship of teneligliptin, a dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes mellitus

AIM

To assess the efficacy, safety and dose-response relationship of once-daily teneligliptin, a novel dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with diet and exercise.

METHODS

In this randomized, double-blind, placebo-controlled, parallel-group study, patients (n = 324) were randomized to receive teneligliptin 10, 20 or 40 mg, or placebo, once daily before breakfast for 12 weeks. The primary endpoint was the change in haemoglobin (Hb)A1c from baseline to week 12.

RESULTS

All teneligliptin-treated groups showed significantly greater reductions in HbA1c and fasting plasma glucose (FPG) than did the placebo group. The differences between the teneligliptin 10, 20 or 40 mg groups and the placebo group for the change in HbA1c were -0.9 [least-squares (LS) mean; 95% confidence interval: -1.0, -0.7], -0.9 (-1.1, -0.7) and -1.0 (-1.2, -0.9)%, respectively (all, p < 0.001). The respective LS means for FPG were -17.8 (-23.4, -12.1), -16.9 (-22.6, -11.2) and -20.0 (-25.7, -14.3) mg/dl (all, p < 0.001). There were no significant differences in HbA1c among the three doses of teneligliptin. The incidence of adverse events and adverse drug reactions was similar in each group. The incidence of hypoglycaemia was not significantly different among the four groups.

CONCLUSIONS

Treatment with teneligliptin for 12 weeks provided significant and clinically meaningful reductions in HbA1c and FPG across the dose range studied and was generally well tolerated in Japanese patients with T2DM.

Assessment of cardiometabolic risk and prevalence of meeting treatment guidelines among patients with type 2 diabetes stratified according to their use of insulin and/or other diabetic medications: results from INSPIRE ME IAA

AIM

Visceral adipose tissue (VAT) and liver fat (LF) are strongly associated with type 2 diabetes. It is not known, however, how diabetes treatment and/or risk factor management modulates the association between VAT, LF and diabetes. The aim was to determine the level of VAT and LF in patients with type 2 diabetes according to their treatment status and achievement of the American Diabetes Association's (ADA) diabetes management goals.

METHODS

We performed a cross-sectional analysis of the baseline data of the International Study of the Prediction of Intra-Abdominal Adiposity and its Relationship with Cardiometabolic risk/Intra-Abdominal Adiposity (INSPIRE ME IAA), a 3-year prospective cardiometabolic imaging study conducted in 29 countries. Patients (n = 3991) were divided into four groups: (i) those without type 2 diabetes (noT2D n = 1003 men, n = 1027 women); (ii) those with type 2 diabetes but not treated with diabetes medications (T2Dnomeds n = 248 men, n = 198 women); (iii) those with type 2 diabetes and treated with diabetes medications but not yet using insulin (T2Dmeds-ins n = 591 men, n = 484 women) and (iv) those with type 2 diabetes and treated with insulin (T2Dmeds+ins n = 233 men, n = 207 women). Abdominal and liver adiposity were measured by computed tomography.

RESULTS

Fewer patients with high VAT or LF achieved the ADA's goals for high-density lipoprotein cholesterol (HDL-C) or triglycerides compared to patients with low VAT or LF. Visceral adiposity (p = 0.02 men, p = 0.003 women) and LF (p = 0.0002 men, p = 0.0004 women) increased among patients who met fewer of the ADA treatment criteria, regardless of type 2 diabetes treatment.

CONCLUSION

Residual cardiometabolic risk exists among patients with type 2 diabetes characterized by elevated VAT and LF.

Genome-wide association study in a Chinese population identifies a susceptibility locus for type 2 diabetes at 7q32 near PAX4

AIMS/HYPOTHESIS

Most genetic variants identified for type 2 diabetes have been discovered in European populations. We performed genome-wide association studies (GWAS) in a Chinese population with the aim of identifying novel variants for type 2 diabetes in Asians.

METHODS

We performed a meta-analysis of three GWAS comprising 684 patients with type 2 diabetes and 955 controls of Southern Han Chinese descent. We followed up the top signals in two independent Southern Han Chinese cohorts (totalling 10,383 cases and 6,974 controls), and performed in silico replication in multiple populations.

RESULTS

We identified CDKN2A/B and four novel type 2 diabetes association signals with p < 1 × 10(-5) from the meta-analysis. Thirteen variants within these four loci were followed up in two independent Chinese cohorts, and rs10229583 at 7q32 was found to be associated with type 2 diabetes in a combined analysis of 11,067 cases and 7,929 controls (p meta = 2.6 × 10(-8); OR [95% CI] 1.18 [1.11, 1.25]). In silico replication revealed consistent associations across multiethnic groups, including five East Asian populations (p meta = 2.3 × 10(-10)) and a population of European descent (p = 8.6 × 10(-3)). The rs10229583 risk variant was associated with elevated fasting plasma glucose, impaired beta cell function in controls, and an earlier age at diagnosis for the cases. The novel variant lies within an islet-selective cluster of open regulatory elements. There was significant heterogeneity of effect between Han Chinese and individuals of European descent, Malaysians and Indians.

CONCLUSIONS/INTERPRETATION

Our study identifies rs10229583 near PAX4 as a novel locus for type 2 diabetes in Chinese and other populations and provides new insights into the pathogenesis of type 2 diabetes.

Protection from non-alcoholic steatohepatitis and liver tumourigenesis in high fat-fed insulin receptor substrate-1-knockout mice despite insulin resistance

AIMS/HYPOTHESIS

Epidemiological studies have revealed that obesity and diabetes mellitus are independent risk factors for the development of non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma. However, the debate continues on whether insulin resistance as such is directly associated with NASH and liver tumourigenesis. Here, we investigated the incidence of NASH and liver tumourigenesis in Irs1 ( -/- ) mice subjected to a long-term high-fat (HF) diet. Our hypothesis was that hepatic steatosis, rather than insulin resistance may be related to the pathophysiology of these conditions.

METHODS

Mice (8 weeks old, C57Bl/6J) were given free access to standard chow (SC) or an HF diet. The development of NASH and liver tumourigenesis was evaluated after mice had been on the above-mentioned diets for 60 weeks. Similarly, Irs1 ( -/- ) mice were also subjected to an HF diet for 60 weeks.

RESULTS

Long-term HF diet loading, which causes obesity and insulin resistance, was sufficient to induce NASH and liver tumourigenesis in the C57Bl/6J mice. Obesity and insulin resistance were reduced by switching mice from the HF diet to SC, which also protected these mice against the development of NASH and liver tumourigenesis. However, compared with wild-type mice fed the HF diet, Irs1 ( -/- ) mice fed the HF diet were dramatically protected against NASH and liver tumourigenesis despite the presence of severe insulin resistance and marked postprandial hyperglycaemia.

CONCLUSIONS/INTERPRETATION

IRS-1 inhibition might protect against HF diet-induced NASH and liver tumourigenesis, despite the presence of insulin resistance.

Depletion of homeodomain-interacting protein kinase 3 impairs insulin secretion and glucose tolerance in mice

AIMS/HYPOTHESIS

Insufficient insulin secretion and reduced pancreatic beta cell mass are hallmarks of type 2 diabetes. Here, we focused on a family of serine-threonine kinases known as homeodomain-interacting protein kinases (HIPKs). HIPKs are implicated in the modulation of Wnt signalling, which plays a crucial role in transcriptional activity, and in pancreas development and maintenance. The aim of the present study was to characterise the role of HIPKs in glucose metabolism.

METHODS

We used RNA interference to characterise the role of HIPKs in regulating insulin secretion and transcription activity. We conducted RT-PCR and western blot analyses to analyse the expression and abundance of HIPK genes and proteins in the islets of high-fat diet-fed mice. Glucose-induced insulin secretion and beta cell proliferation were measured in islets from Hipk3 ( -/- ) mice, which have impaired glucose tolerance owing to an insulin secretion deficiency. The abundance of pancreatic duodenal homeobox (PDX)-1 and glycogen synthase kinase (GSK)-3β phosphorylation in Hipk3 ( -/- ) islets was determined by immunohistology and western blot analyses.

RESULTS

We found that HIPKs regulate insulin secretion and transcription activity. Hipk3 expression was most significantly increased in the islets of high-fat diet-fed mice. Furthermore, glucose-induced insulin secretion and beta cell proliferation were decreased in the islets of Hipk3 ( -/- ) mice. Levels of PDX1 and GSK-3β phosphorylation were significantly decreased in Hipk3 ( -/- ) islets.

CONCLUSIONS/INTERPRETATION

Depletion of HIPK3 impairs insulin secretion and glucose tolerance. Decreased levels of HIPK3 may play a substantial role in the pathogenesis of type 2 diabetes.

Monocyte chemoattractant protein-1 (MCP-1) deficiency enhances alternatively activated M2 macrophages and ameliorates insulin resistance and fatty liver in lipoatrophic diabetic A-ZIP transgenic mice

AIMS/HYPOTHESIS

Monocyte chemoattractant protein-1 (MCP-1)/chemokine (C-C motif) ligand (CCL) 2 (CCL2) secreted from white adipose tissue (WAT) in obesity has been reported to contribute to tissue macrophage accumulation and insulin resistance by inducing a chronic inflammatory state. MCP-1 has been shown to be elevated in the fatty liver of lipoatrophic A-ZIP-transgenic (A-ZIP-Tg) mice. Treatment of these mice with the CC chemokine receptor (CCR) 2 antagonist has been shown to ameliorate the hyperglycaemia, hyperinsulinaemia and hepatomegaly, in conjunction with reducing liver inflammation. However, since CCR2 antagonists can block not only MCP-1 but also MCP-2 (CCL8) and MCP-3 (CCL7), it remains unclear whether MCP-1 secreted from the liver could contribute to hyperglycaemia, hyperinsulinaemia and hepatomegaly in conjunction with liver inflammation, as well as to the M1 and M2 states of macrophage polarisation.

METHODS

To address these issues, we analysed the effects of targeted disruption of MCP-1 in A-ZIP-Tg mice.

RESULTS

MCP-1 deficiency alone or per se resulted in a significant amelioration of insulin resistance in A-ZIP-Tg mice, which was associated with a suppression of extracellular signal-regulated protein kinase (ERK)-1/2 and p38 mitogen-activated protein kinase (p38MAPK) phosphorylation in liver. Although MCP-1 deficiency did not reduce the expression of macrophage markers, it increased the expression of the genes encoding M2 macrophage markers such as Arg1 and Chi3l3, as well as significantly reducing the triacylglycerol content of livers from A-ZIP-Tg mice. CONCLUSIONS/ INTERPRETATION: Our data clearly indicated that MCP-1 deficiency improved insulin resistance and hepatic steatosis in A-ZIP-Tg mice and was associated with switching macrophage polarisation and suppressing ERK-1/2 and p38MAPK phosphorylation.

Effects of once-daily teneligliptin on 24-h blood glucose control and safety in Japanese patients with type 2 diabetes mellitus: a 4-week, randomized, double-blind, placebo-controlled trial

AIM

To assess blood glucose control over 24 h and the safety of teneligliptin 10 and 20 mg, a novel dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes mellitus inadequately controlled with diet and exercise.

METHODS

Ninety-nine patients were administered teneligliptin 10 or 20 mg or placebo before breakfast for 4 weeks in a randomized, double-blind, placebo-controlled, parallel-group study.

RESULTS

Both teneligliptin-treated groups showed significantly smaller 2-h postprandial glucose (2-h PPG), 24-h mean glucose and fasting plasma glucose values than the placebo group. The differences between the teneligliptin 10 mg and placebo groups in changes in 2-h PPG after each meal were -50.7 ± 7.8, -34.8 ± 9.2 and -37.5 ± 7.5 mg/dl at breakfast, lunch and dinner, respectively [least-squares (LS) means ± standard error (s.e.), all, p < 0.001]. The corresponding LS means ± s.e. for teneligliptin 20 mg versus placebo were -38.1 ± 7.8, -28.6 ± 9.2 and -36.1 ± 7.5 mg/dl, respectively (p < 0.001, p < 0.01, p < 0.001, respectively). Both doses of teneligliptin increased postprandial plasma active glucagon-like peptide-1 concentrations compared with placebo. The incidence of adverse events and drug-related adverse events was similar among groups. There were no hypoglycaemic symptoms or serious adverse events.

CONCLUSIONS

Once-daily teneligliptin improved blood glucose levels over 24 h without hypoglycaemia.

Control of beta cell function and proliferation in mice stimulated by small-molecule glucokinase activator under various conditions

AIMS/HYPOTHESIS

We investigated changes in the expression of genes involved in beta cell function and proliferation in mouse islets stimulated with glucokinase activator (GKA) in order to elucidate the mechanisms by which GKA stimulates beta cell function and proliferation.

METHODS

Islets isolated from mice were used to investigate changes in the expression of genes related to beta cell function and proliferation stimulated by GKA. In addition, Irs2 knockout (Irs2 (-/-)) mice on a high-fat diet or a high-fat diet containing GKA were used to investigate the effects of GKA on beta cell proliferation in vivo.

RESULTS

In wild-type mice, Irs2 and Pdx1 expression was increased by GKA. In Irs2 (-/-) mice, GKA administration increased the glucose-stimulated secretion of insulin and Pdx1 expression, but not beta cell proliferation. It was particularly noteworthy that oxidative stress inhibited the upregulation of the Irs2 and Pdx1 genes induced by GKA. Moreover, whereas neither GKA alone nor exendin-4 alone upregulated the expression of Irs2 and Pdx1 in the islets of db/db mice, prior administration of exendin-4 to the mice caused GKA to increase the expression of these genes.

CONCLUSIONS/INTERPRETATION

GKA-stimulated IRS2 production affected beta cell proliferation but not beta cell function. Oxidative stress diminished the effects of GKA on the changes in expression of genes involved in beta cell function and proliferation. A combination of GKA and an incretin-related agent might therefore be effective in therapy.

Adiponectin, adiponectin receptors, and epigenetic regulation of adipogenesis

We studied the molecular mechanism of obesity-induced insulin resistance and adipogenesis. Plasma adiponectin and adiponectin receptor (AdipoR1) in muscle are down-regulated in obesity. Analysis of muscle-specific AdipoR1 knockout mice revealed the pivotal role of adiponectin/AdipoR1 in the regulation of mitochondrial biogenesis via AMPK- and SIRT1-mediated PGC-1α activation as well as Ca(2+)-dependent up-regulation of PGC-1α expression. Reduced adiponectin/AdipoR1 signals in muscle in obesity appear to cause PGC-1α inactivation as well as down-regulation and consequently impaired mitochondrial biogenesis and insulin resistance. In the epigenetic analysis of adipogenesis, we demonstrated that adipocyte-specific formaldehyde-assisted isolation of regulatory elements (FAIRE) peaks are associated with genes up-regulated by adipogenesis, whereas preadipocyte-specific FAIRE peaks are associated with genes down-regulated by adipogenesis. Computational motif analyses of adipocyte-specific FAIRE peaks confirmed PPARγ and CCAAT-enhancer binding proteins (C/EBPs) on the top list, consistent with their crucial roles in adipogenic transcription, and also revealed NFIA and NFIB to be important regulators of proper adipocyte differentiation.

The diabetogenic VPS13C/C2CD4A/C2CD4B rs7172432 variant impairs glucose-stimulated insulin response in 5,722 non-diabetic Danish individuals

AIMS/HYPOTHESIS

A genome-wide association study in the Japanese population reported two genome-wide significant loci associated with type 2 diabetes of which the VPS13C/C2CD4A/C2CD4B locus was replicated in Europeans. We looked for potential associations between the diabetogenic VPS13C/C2CD4A/C2CD4B rs7172432 variant and diabetes-related intermediary traits.

METHODS

We genotyped the rs7172432 variant in the population-based Inter99 cohort (n = 6,784) and analysed quantitative diabetes-related traits in 5,722 non-diabetic participants who all were examined by an OGTT.

RESULTS

The diabetes-associated A allele was associated with 0.60 cm higher waist circumference (p = 0.004), 0.037 mmol/l higher fasting plasma glucose (p = 4 × 10(-5)) and 0.11 mmol/l higher plasma glucose at 30 min during an OGTT (p = 4 × 10(-4)). In analyses adjusted for concomitant insulin sensitivity levels the diabetogenic allele was associated with a lower acute glucose-stimulated insulin response (GSIR) as estimated by 30 min serum insulin (β = -0.039, p = 2 × 10(-7)), insulinogenic index (β = -0.057, p = 1 × 10(-8)) and BIGTT-acute insulin release (β = -0.041, p = 9 × 10(-9)). As rs7172432 is situated in a region previously associated with glycaemic traits, we tested linkage disequilibrium (LD) with the reported regional lead single-nucleotide polymorphisms for fasting (rs11071657) and 2 h plasma glucose (rs17271305), and performed conditional analyses of rs7172432. Rs7172432 showed moderate LD with rs11071657 and rs17271305 (R (2) < 0.34) and we found strong association by almost unchanged effect sizes of rs7172432 with plasma glucose and estimates of GSIR in analyses conditional on rs11071657 and rs17271305.

CONCLUSIONS/INTERPRETATION

The diabetogenic VPS13C/C2CD4A/C2CD4B rs7172432 A allele associates with GSIR in non-diabetic individuals from the general population, suggesting an impaired beta cell function as an intermediary diabetes-related trait.

Living-donor liver transplantation at the University of Tokyo, 1996-2011: the impact of HLA matching and a positive crossmatch on long-term survival and tolerance

OBJECTIVE

We analyzed a single center's experience during 16 years of living-donor liver transplantation (LDLT). The impacts of HLA mismatches and positive crossmatches on long term outcomes and tolerance were evaluated.

METHODS

This study was of primary LDLTs of consecutive patients from January 1996 to December 2011; re-transplants were not included. Long-term survival was compared by primary disease, number of HLA mismatches, and crossmatches. Demographics and complications after transplantation between pediatric recipients who achieved clinical operational tolerance and those who did not were compared.

RESULTS

One-year liver graft survival rates for adult and pediatric cases were 90.4% and 91.9%, respectively; the 5-year rates were 83.1% and 89.2%, respectively; the 10-year rates were 79.7% and 89.2%, respectively; and 15-year rates were 65.9% and 83.8%, respectively. For the grafts that survived more than one year, the 10-year rates for adult and pediatric cases were 88.2% and 97.0%, respectively. The 10-year rates for adult LDLT in 0 mismatches, 1-2 mismatches, 3-4 mismatches, and 5-6 mismatches were 79.2%, 86.8%, 77.4%, and 69.4%, respectively. Although the survival rates were not significantly different, the survival rates were lowest in LDLT recipients with 5-6 HLA mismatches. Ten-year liver graft survival rates for adult LDLT with negative T-cell crossmatch, and positive T-cell crossmatch were 80.0% and 71.1%, respectively. The 1-year liver graft survival rates for adult LDLT with negative B-cell crossmatch, and positive B-cell crossmatch were 90.6% and 88.2%, respectively. None of the factors--age of recipients and donors, primary disease, donor gender, relationship of donors to recipients, positive crossmatches, or number of HLA mismatches--was significantly different between COT and non-COT recipients, except for recipient gender (p = 0.01); in COT cases, there were more female recipients (88.9%) than male (11.1%). Post-transplant complications--acute rejection rate in one year post-transplant, biliary complications rate, and vascular complication rate--were not significantly different between COT and non-COT recipients.

CONCLUSIONS

High long-term survival was achieved by both adult and pediatric recipients. Even higher survival can be achieved by improving early graft loss. Further studies are necessary to determine the impact of HLA mismatches and positive crossmatches on long-term outcomes and tolerance.

Abstract P6-08-02: Comparative Analysis between Primary and Secondary in Breast Tumors by Polymorphysim of Androgen Receptor Gene and Mitochondria D-Loop Somatic Mutation

Background: It has not been fully understood how we can differentiate a new primary breast cancer from a recurrent tumor, when second tumor arises in ipsilateral breast after the surgery for primary breast cancer. To address this research question, we estimate the usefulness of a method analyzing polymorphism of androgen receptor gene and mitochondrial D-loop somatic mutation.

Materials and methods: 1) Select patients: Among the 558 patients who received the breast conservative surgery in Tokai University Hospital (1991∼2004), 9 ipsilateral breast tumors and 11 contralateral breast tumors were submitted for the analysis. 2) Formalin-fixed paraffin-embedded (FFPE) sections of non-neoplastic lymph node were examined whether polymorphism of AR gene present or not. 3) When polymorphism of AR gene in non-neoplastic lymphoid tissue were demonstrated, ipsilateral and contralateral breast cancers were further examined. 4) When AR gene in breast cancers on same allele in primary and secondary tumors, FFPE sections were further analyzed by mutaion analysis of mitochondrial D-loop region.

Results: 1) Polymorphism of AR was demonstrated in 8/9 (88.9%) and 9/11 (81.8%) non-neoplastic lymph nodes obtained from the patients who had ipsilateral and contralateral breast tumor, respectively. 2) Only 2 of 8 ipsilateral breast cancers demonstrated AR polymorphism different from primary cancer. In contrast, 6 of 9 contralateral breast cancers had different polymorphism for AR from primary breast cancers. 3) Analysis of mitochondrial D-loop mutation showed that 8 seconary ipsilateral cancers had different mutation in 3/8 (37.5%), identical mutation in 3/8 (37.5%), and no mutation in 2/8 (25.0%).

Results of analysis for ipsilateral secondary breast cancers

Conclusion: Half of the ipsilateral in breast secondary tumors were estimated as new primary lesions by molecular estimation. Combination analyses of AR gene polymorphism and mitochondrial D-loop somatic mutation unable us to distinguish between true recurrent or new primary cancers.

Efficacy and safety of sitagliptin monotherapy compared with voglibose in Japanese patients with type 2 diabetes: a randomized, double-blind trial

OBJECTIVE

To compare the efficacy and safety of sitagliptin (a dipeptidyl peptidase-4 inhibitor) and voglibose (an alpha-glucosidase inhibitor) monotherapy in Japanese patients with type 2 diabetes who have inadequate glycaemic control (HbA1c > or =6.5% and <10.0%) on diet and exercise.

METHODS

In a multi-center, randomized, double-blind, parallel-group study, 319 patients were randomized (1:1) to 12-week treatment with sitagliptin 50 mg once daily or voglibose 0.2 mg thrice daily before meals. The primary analysis assessed whether sitagliptin was non-inferior to voglibose in lowering HbA1c.

RESULTS

After 12 weeks, sitagliptin was non-inferior to voglibose for HbA1c-lowering efficacy. Furthermore, sitagliptin was superior to voglibose, providing significantly greater reductions in HbA1c from baseline [least squares mean changes in HbA1c [95% confidence intervals (CI)] = -0.7% (-0.8 to -0.6) and -0.3% (-0.4 to -0.2), respectively; between-group difference = -0.4% (-0.5 to -0.3), p < 0.001]. Sitagliptin was also superior to voglibose on other key efficacy endpoints, including change from baseline in 2-h postmeal glucose (-2.8 mmol/l vs. -1.8 mmol/l, p < 0.001) and fasting plasma glucose (-1.1 mmol/l vs. -0.5 mmol/l, p < 0.001). After 12 weeks, the incidences of clinical adverse experiences (AEs), drug-related AEs and gastrointestinal AEs in the sitagliptin group (48.5, 10.4 and 18.4%, respectively) were significantly (p < 0.05) lower than those in the voglibose group (64.7, 26.3 and 34.6%, respectively). The incidences of hypoglycaemia, serious AEs and discontinuations due to AEs were low and similar in both groups.

CONCLUSIONS

In Japanese patients with type 2 diabetes, once-daily sitagliptin monotherapy showed greater efficacy and better tolerability than thrice-daily voglibose over 12 weeks.

Colestilan monotherapy significantly improves glycaemic control and LDL cholesterol levels in patients with type 2 diabetes: a randomized double-blind placebo-controlled study

AIM

To evaluate the plasma glucose-reducing activity and safety of colestilan, a bile acid sequestrant, in patients with type 2 diabetes.

METHODS

Patients with fasting plasma glucose (FPG) 7.2-11.1 mmol/l and HbA (1c)> or =7.0% were randomly allocated in double-blind manner to receive colestilan or placebo therapy for 12 weeks.

RESULTS

A total of 183 patients entered the double-blind treatment phase. At 12 weeks, colestilan significantly reduced HbA (1c) and FPG vs. placebo by 0.9% and 1.2 mmol/l respectively (both p < 0.001). A significant (p < 0.001) 22.5% reduction of LDL cholesterol was also observed in the 172 patients evaluated (colestilan group: n = 86; placebo group: n = 86). However, no significant reduction of fasting insulin was observed (p = 0.087). No incidence of hypoglycaemia was reported in this study.

CONCLUSION

Colestilan improved glycaemic control and reduced LDL cholesterol levels in patients with type 2 diabetes.

Simultaneous pancreas-kidney transplantation in the United States: an analysis of the UNOS registry

The rate of chronic pancreas graft loss in simultaneous pancreas kidney transplantation has remained almost unchanged despite induction therapy. Since 1987, seven major immunosuppressive induction agents-basiliximab, daclizumab, ALG, eATG, OKT 3, alembuzumab, rATG-have been used as immunosuppressive induction agents. Those agents improved short-term survival by preventing acute rejection, but improvement of short-term survival has not translated into improved long-term graft survival. As with most solid organ transplants, there is a need for means to control chronic rejection to improve long-term graft survival.

Effects of insulin glulisine as mono- or add-on therapy in patients with type 2 diabetes mellitus

AIM

To evaluate the safety and efficacy of insulin glulisine (glulisine) with and without oral antidiabetic drugs (OAD; sulphonylurea or sulphonylurea + biguanide) relative to that of OAD alone in Japanese and Korean patients with inadequately controlled type 2 diabetes mellitus (T2DM).

METHODS

In an open, randomized, parallel-group, comparative, controlled trial, 387 patients were randomized and treated with glulisine + OAD (n = 130), glulisine monotherapy (n = 127) or OAD only (n = 130) for 16 weeks. Glulisine was self-injected subcutaneously three times daily (0-15 minutes before meals) at a starting dose of >or=0.2 U/kg/day. Patients titrated the glulisine dose to achieve a 2-h postprandial plasma glucose (2h-PPG) level of 7.1-9.5 mmol/l (128-172 mg/dl) by administering at least one additional unit at each appropriate meal time if the 2h-PPG level was > 9.5 and < 11.1 mmol/l (> 172 and < 200 mg/dl) and by administering at least two additional units if the 2h-PPG level was >or= 11.1 mmol/l (>or= 200 mg/dl). Therapy with OAD was continued at the stable baseline regimen. The primary efficacy endpoint was change in haemoglobin A(1c) (HbA(1c)) from baseline to endpoint in the intention-to-treat population.

RESULTS

At baseline, therapy with OAD was a sulphonylurea only and a sulphonylurea + a biguanide in approximately 24 and 76% of patients respectively. Both glulisine groups had larger reductions in adjusted mean HbA(1c) than the OAD-only group (glulisine + OAD, -2.07%; glulisine monotherapy, -1.25%; OAD only, -0.61%). Superiority of glulisine + OAD and glulisine monotherapy vs. OAD only was shown by differences in adjusted mean HbA(1c) change from baseline values of -1.46% (p < 0.0001) and -0.64% (p < 0.0001) respectively. Both glulisine groups had better 2h-PPG control than the OAD-only group. Mean daily glulisine doses increased from baseline to endpoint (glulisine + OAD, 13.3-22.5 U; glulisine monotherapy, 14.2-38.0 U). The rate of all symptomatic hypoglycaemia events per patient-year in the entire treatment phase was 11.9 in the glulisine + OAD group, 8.8 in the glulisine monotherapy group and 1.7 in the OAD-only group. There was only one event of severe hypoglycaemia, which occurred in the glulisine + OAD group. Efficacy and safety were similar in Japanese and Korean subpopulations.

CONCLUSIONS

Both glulisine + OAD and glulisine monotherapy were well tolerated and effective for Japanese and Korean patients with T2DM mellitus inadequately controlled by OAD therapy alone.

Efficacy and safety of insulin glulisine in Japanese patients with type 1 diabetes mellitus

AIM

The rapid-acting insulin analogue insulin glulisine (glulisine) was compared with insulin lispro (lispro) for efficacy and safety in Japanese patients with type 1 diabetes mellitus (T1DM), using insulin glargine (glargine) as basal insulin.

METHODS

This was an open, randomized, parallel-group, comparative non-inferiority study. The primary efficacy measure was change in adjusted mean haemoglobin A1c (HbA1c) from baseline to endpoint. Safety and treatment satisfaction using the Diabetes Treatment Satisfaction Questionnaire (DTSQ) were also assessed. Patients were treated for 28 weeks with either glulisine or lispro administered 0-15 min before a meal. Doses were titrated to obtain 2-h postprandial plasma glucose (2h-PPG) of 7.11-9.55 mmol/l (128-172 mg/dl). All patients were concomitantly treated with glargine at bedtime, titrated to obtain a fasting (prebreakfast) plasma glucose level of 5.27-7.11 mmol/l (95-128 mg/dl).

RESULTS

Baseline mean HbA1c values were similar for the glulisine (n = 132) and lispro (n = 135) groups (7.44 and 7.50% respectively). From baseline to endpoint, adjusted mean HbA1c increased by 0.10% in the glulisine group and by 0.04% in the lispro group. Non-inferiority of glulisine compared with lispro was shown. There were no significant differences between glulisine and lispro in adjusted mean 2h-PPG [glulisine, 9.06 mmol/l (163 mg/dl) vs. lispro, 8.13 mmol/l (146 mg/dl); p = 0.065] and change in adjusted mean daily rapid-acting insulin dose (glulisine, 0.26 U vs. lispro, 0.26 U; p = 0.994) at study endpoint. There was a significant difference for change in adjusted mean daily basal insulin dose from baseline to study endpoint (glulisine, -0.54 U vs. lispro, 0.26 U; p = 0.013). The most common serious adverse events were hypoglycaemia-related events (hypoglycaemia, hypoglycaemic seizure and hypoglycaemic coma) with no difference observed between the two groups [glulisine, 6.8% (9/132) vs. lispro, 4.4% (6/135); p = 0.437]. No noteworthy differences were observed for change in insulin antibodies from baseline to endpoint. Assessment of treatment satisfaction score and perceived frequency of hyperglycaemia and hypoglycaemia by DTSQ showed no changes from baseline in either group.

CONCLUSIONS

Glulisine was as effective as lispro with respect to change in HbA1c and was well tolerated when used in combination with glargine in Japanese patients with T1DM.

Replication study for the association of new meta-analysis-derived risk loci with susceptibility to type 2 diabetes in 6,244 Japanese individuals

AIMS/HYPOTHESIS

Additional susceptibility loci for type 2 diabetes have been identified by a meta-analysis of genome-wide association studies (GWASs) in European populations. To examine further the roles of these new loci, we performed a replication study for the association of these single-nucleotide polymorphism (SNP) loci with the disease in three independent Japanese populations.

METHODS

We genotyped seven of the 11 SNPs that emerged in stage 2 of the meta-analysis for European GWASs (rs864745 in JAZF1, rs12779790 near CDC123/CAMK1D, rs7961581 near TSPAN8/LGR5, rs4607103 near ADAMTS9, rs10923931 in NOTCH2, rs1153188 near DCD and rs9472138 near VEGFA) for three independent Japanese populations (first set, 1,630 type 2 diabetes patients vs 1,064 controls; second set, 1,272 type 2 diabetes patients vs 856 controls; third set, 486 type 2 diabetes patients vs 936 controls) using a TaqMan assay. The association of the SNP loci in each population was analysed using a logistic regression analysis, adjusting for age, sex and BMI, and the data were evaluated by a meta-analysis.

RESULTS

A meta-analysis for the three case-control studies identified a nominal association of rs864745 in JAZF1 with type 2 diabetes (OR 1.148, 95% CI 1.034-1.275, p = 0.0098, corrected p = 0.069). The association of other loci did not reach statistically significant levels (nominal p > 0.05).

CONCLUSIONS/INTERPRETATION

From these results the contribution of these seven loci in conferring susceptibility to type 2 diabetes is considered minor in the Japanese population, if they are present.

The molecular basis and clinical characteristics of Maternally Inherited Diabetes and Deafness (MIDD), a recently recognized diabetic subtype

Diabetes mellitus comprises a number of diseases with hyperglycemia as hallmark. Currently, multiple genetic factors are being recognized which contribute to the development of diabetes or which may modulate its clinical expression. This review presents an overview of our current knowledge on a diabetic subtype which associates with a single mutation in mitochondrial DNA. Based on the triad of Maternal Inheritance, Diabetes and Deafness we propose the name Maternally Inherited Diabetes and Deafness (MIDD) for this syndrome. In Northwestern Europe MIDD affects approximately 1.3% of all diabetic individuals.

Adiponectin suppresses colorectal carcinogenesis under the high-fat diet condition

BACKGROUND AND AIMS

The effect of adiponectin on colorectal carcinogenesis has been proposed but not fully investigated. We investigated the effect of adiponectin deficiency on the development of colorectal cancer.

METHODS

We generated three types of gene-deficient mice (adiponectin-deficient, adiponectin receptor 1-deficient, and adiponectin receptor 2-deficient) and investigated chemical-induced colon polyp formation and cell proliferation in colon epithelium. Western blot analysis was performed to elucidate the mechanism which affected colorectal carcinogenesis by adiponectin deficiency.

RESULTS

The numbers of colon polyps were significantly increased in adiponectin-deficient mice compared with wild-type mice fed a high-fat diet. However, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. A significant increase in cell proliferative activity was also observed in the colonic epithelium of the adiponectin-deficient mice when compared with wild-type mice fed a high-fat diet; however, no difference was observed between wild-type and adiponectin-deficient mice fed a basal diet. Similarly, an increase in epithelial cell proliferation was observed in adiponectin receptor 1-deficient mice, but not in adiponectin receptor 2-deficient mice. Western blot analysis revealed activation of mammalian target of rapamycin, p70 S6 kinase, S6 protein and inactivation of AMP-activated protein kinase in the colon epithelium of adiponectin-deficient mice fed with high-fat diet.

CONCLUSIONS

Adiponectin suppresses colonic epithelial proliferation via inhibition of the mammalian target of the rapamycin pathway under a high-fat diet, but not under a basal diet. These studies indicate a novel mechanism of suppression of colorectal carcinogenesis induced by a Western-style high-fat diet.

Crucial role of insulin receptor substrate-2 in compensatory beta-cell hyperplasia in response to high fat diet-induced insulin resistance

In type 2 diabetes, there is a defect in the regulation of functional beta-cell mass to overcome high-fat (HF) diet-induced insulin resistance. Many signals and pathways have been implicated in beta-cell function, proliferation and apoptosis. The co-ordinated regulation of functional beta-cell mass by insulin signalling and glucose metabolism under HF diet-induced insulin-resistant conditions is discussed in this article. Insulin receptor substrate (IRS)-2 is one of the two major substrates for the insulin signalling. Interestingly, IRS-2 is involved in the regulation of beta-cell proliferation, as has been demonstrated using knockout mice models. On the other hand, in an animal model for human type 2 diabetes with impaired insulin secretion because of insufficiency of glucose metabolism, decreased beta-cell proliferation was observed in mice with beta-cell-specific glucokinase haploinsufficiency (Gck(+/) (-)) fed a HF diet without upregulation of IRS-2 in beta-cells, which was reversed by overexpression of IRS-2 in beta-cells. As to the mechanism underlying the upregulation of IRS-2 in beta-cells, glucose metabolism plays an important role independently of insulin, and phosphorylation of cAMP response element-binding protein triggered by calcium-dependent signalling is the critical pathway. Downstream from insulin signalling via IRS-2 in beta-cells, a reduction in FoxO1 nuclear exclusion contributes to the insufficient proliferative response of beta-cells to insulin resistance. These findings suggest that IRS-2 is critical for beta-cell hyperplasia in response to HF diet-induced insulin resistance.