Exercise-Induced Post-Ischemic Left Ventricular Delayed Relaxation or Diastolic Stunning Is it a Reliable Marker in Detecting Coronary Artery Disease?

ObjectivesThe aim of this study was to determine whether post-ischemic left ventricular (LV) delayed relaxation could be detected by using strain imaging (SI) derived from 2-dimensional speckle-tracking echocardiography in patients with stable effort angina.BackgroundRegional LV delayed relaxation during early diastole is a sensitive sign of acute myocardial ischemia and may persist beyond recovery of exercise-induced ischemia.MethodsRegional LV transverse strain changes during the first one-third of diastole duration (strain imaging diastolic index [SI-DI]) were determined at baseline and 5 and 10 min after the exercise test in 162 patients with stable effort angina. The ratio of SI-DI before and after exercise (SI-DI ratio) was used to identify regional LV delayed relaxation.ResultsA total of 117 patients had significant (≥50% of luminal diameter) coronary stenoses. The mean SI-DI decreased from 78.0 ± 9.7% to 27.6 ± 16.0% (p < 0.0001) in 191 territories perfused by coronary arteries with significant stenoses 5 min after the treadmill exercise, whereas it remained unchanged in 280 territories perfused by arteries with nonsignificant stenoses. Ten minutes after exercise, regional delayed relaxation was still observed in 85% of territories perfused by stenotic coronary arteries. An SI-DI ratio with a cutoff value of 0.74 had a sensitivity of 97% and a specificity of 93% to detect significant coronary stenosis in the receiver-operator characteristic curve.ConclusionsDetection of post-ischemic regional LV delayed relaxation or diastolic stunning after treadmill exercise using SI is a sensitive and reliable method for the detection of coronary artery disease

Efficacy and safety of luseogliflozin added to various oral antidiabetic drugs in Japanese patients with type 2 diabetes mellitus

Introduction: Two studies were carried out to investigate the efficacy and safety of luseogliflozin added to existing oral antidiabetic drugs (OADs) in Japanese type 2 diabetic patients inadequately controlled with OAD monotherapy. Materials and Methods: In the trial involving add‐on to sulfonylureas (study 03‐1), patients were randomly assigned to receive luseogliflozin 2.5 mg or a placebo for a 24‐week double‐blind period, followed by a 28‐week open‐label period. In the open‐label trial involving add‐on to other OADs; that is, biguanides, dipeptidyl peptidase‐4 inhibitors, thiazolidinediones, glinides and α‐glucosidase inhibitors (study 03‐2), patients received luseogliflozin for 52 weeks. Results: In study 03‐1, luseogliflozin significantly decreased glycated hemoglobin at the end of the 24‐week double‐blind period compared with the placebo (–0.88%, P < 0.001), and glycated hemoglobin reduction from baseline at week 52 was –0.63%. In study 03‐2, luseogliflozin added to other OADs significantly decreased glycated hemoglobin from baseline at week 52 (–0.52 to –0.68%, P < 0.001 for all OADs). Bodyweight reduction was observed in all add‐on therapies, even with agents associated with weight gain, such as sulfonylureas and thiazolidinediones. Most adverse events were mild in severity. When added to a sulfonylurea, incidences of hypoglycemia during the double‐blind period were 8.7% and 4.2% for luseogliflozin and placebo, respectively, but no major hypoglycemic episodes occurred. The frequency and incidences of adverse events of special interest for sodium glucose cotransporter 2 inhibitors and adverse events associated with combined OADs were acceptable. Conclusions: Add‐on therapies of luseogliflozin to existing OADs improved glycemic control, reduced bodyweight and were well tolerated in Japanese type 2 diabetic patients. These trials were registered with the Japan Pharmaceutical Information Center (add on to sulfonylurea: JapicCTI‐111507; add on to other OADs: JapicCTI‐111508)

Glucotoxicity Induces Insulin Promoter DNA Methylation in Beta Cells

Recent studies have implicated epigenetics in the pathophysiology of diabetes. Furthermore, DNA methylation, which irreversibly deactivates gene transcription, of the insulin promoter, particularly the cAMP response element, is increased in diabetes patients. However, the underlying mechanism remains unclear. We aimed to investigate insulin promoter DNA methylation in an over-nutrition state. INS-1 cells, the rat pancreatic beta cell line, were cultured under normal-culture-glucose (11.2 mmol/l) or experimental-high-glucose (22.4 mmol/l) conditions for 14 days, with or without 0.4 mmol/l palmitate. DNA methylation of the rat insulin 1 gene (Ins1) promoter was investigated using bisulfite sequencing and pyrosequencing analysis. Experimental-high-glucose conditions significantly suppressed insulin mRNA and increased DNA methylation at all five CpG sites within the Ins1 promoter, including the cAMP response element, in a time-dependent and glucose concentration-dependent manner. DNA methylation under experimental-high-glucose conditions was unique to the Ins1 promoter; however, palmitate did not affect DNA methylation. Artificial methylation of Ins1 promoter significantly suppressed promoter-driven luciferase activity, and a DNA methylation inhibitor significantly improved insulin mRNA suppression by experimental-high-glucose conditions. Experimental-high-glucose conditions significantly increased DNA methyltransferase activity and decreased ten-eleven-translocation methylcytosine dioxygenase activity. Oxidative stress and endoplasmic reticulum stress did not affect DNA methylation of the Ins1 promoter. High glucose but not palmitate increased ectopic triacylglycerol accumulation parallel to DNA methylation. Metformin upregulated insulin gene expression and suppressed DNA methylation and ectopic triacylglycerol accumulation. Finally, DNA methylation of the Ins1 promoter increased in isolated islets from Zucker diabetic fatty rats. This study helps to clarify the effect of an over-nutrition state on DNA methylation of the Ins1 promoter in pancreatic beta cells. It provides new insights into the irreversible pathophysiology of diabetes

Antioxidant α-tocopherol ameliorates glycemic control of GK rats, a model of type 2 diabetes

AbstractWe have shown recently that oxidative stress by chronic hyperglycemia damages the pancreatic β-cells of GK rats, a model of non-obese type 2 diabetes, which may worsen diabetic condition and suggested the administration of antioxidants as a supportive therapy. To determine if natural antioxidant α-tocopherol (vitamin E) has beneficial effects on the glycemic control of type 2 diabetes, GK rats were fed a diet containing 0, 20 or 500 mg/kg diet α-tocopherol. Intraperitoneal glucose tolerance test revealed a significant increment of insulin secretion at 30 min and a significant decrement of blood glucose levels at 30 and 120 min after glucose loading in the GK rats fed with high α-tocopherol diet. The levels of glycated hemoglobin A1c, an indicator of glycemic control, were also reduced. Vitamin E supplementation clearly ameliorated diabetic control of GK rats, suggesting the importance of not only dietary supplementation of natural antioxidants but also other antioxidative intervention as a supportive therapy of type 2 diabetic patients

BUROSUMAB IN TUMOR-INDUCED OSTEOMALACIA

Patients with tumor-induced osteomalacia (TIO), an acquired paraneoplastic condition characterized by osteomalacia due to hypophosphatemia, exhibit a similar clinical picture to those with X-linked hypophosphatemic rickets/osteomalacia (XLH). The human monoclonal anti-fibroblast growth factor 23 (FGF23) antibody burosumab (KRN23) increases serum phosphate and improves bone turnover, fracture healing, pain, and physical function in XLH patients by inhibiting circulating FGF23; thus, burosumab is expected to be an effective treatment for TIO. We report here an interim analysis of a multicenter, open-label, intraindividual dose-adjustment study of burosumab (0.3 to 2.0 mg/kg every 4 weeks) in Japanese and Korean TIO patients. The primary endpoint was the fasting serum phosphate level at each visit. Key secondary endpoints were changes over time in bone biomarkers, pharmacodynamic markers, bone histomorphometric parameters, motor function, and patient-reported outcomes. Safety was assessed based on treatment-emergent adverse events (TEAEs). Thirteen patients received burosumab treatment, of whom 4 underwent bone biopsy. The mean dose after week 112 was approximately 1.0 mg/kg. After the first burosumab administration, mean serum phosphate levels increased and remained above the lower limit of normal and in the normal range from weeks 14 to 112. Bone biomarkers initially increased, reaching maximum values at week 16 or 24, and then gradually decreased. After burosumab treatment, patients were able to walk further (evaluated by the 6-minute walk test), reported decreased pain levels, and showed a tendency toward healing of baseline fractures and pseudofractures. Two patients discontinued, one each due to disease progression and consent withdrawal. Burosumab was generally well tolerated, with no treatment-related TEAEs of grade ≥3 and no treatment-related serious AEs. In conclusion, the interim results of this first study of burosumab to treat TIO patients indicate that this drug has the potential to provide clinical benefit for patients with unresectable tumors. The full study results are eagerly anticipated

A GIP Receptor Agonist Exhibits β-Cell Anti-Apoptotic Actions in Rat Models of Diabetes Resulting in Improved β-Cell Function and Glycemic Control

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

Details on the effect of very short dual antiplatelet therapy after drug-eluting stent implantation in patients with high bleeding risk: insight from the STOPDAPT-2 trial

Previously we briefly reported the effect of 1-month dual antiplatelet therapy (DAPT) for patients with high bleeding risk (HBR) receiving percutaneous coronary intervention (PCI) in the STOPDAPT-2 trial, but full analysis data have not been available. We conducted post hoc subgroup analysis regarding the effect of very short DAPT for HBR patients in STOPDAPT-2 trial. The primary endpoint was a 1-year composite of cardiovascular (cardiovascular death, myocardial infarction, definite stent thrombosis, or stroke) and bleeding (TIMI major/minor bleeding) outcomes. Major secondary endpoints were 1-year cardiovascular composite endpoint and bleeding endpoint. HBR was defined by the academic research consortium (ARC) HBR criteria. Among the 3009 study patients, 1054 (35.0%) were classified as HBR and 1955 (65.0%) were as non-HBR. There were no significant interactions between HBR/non-HBR subgroups and the assigned DAPT group on the primary endpoint (HBR; 3.48% vs. 5.98%, HR 0.57, 95% CI 0.32-1.03, and non-HBR; 1.81% vs. 2.36%, HR 0.78, 95% CI 0.42-1.45; P for interaction = 0.48), the major secondary cardiovascular endpoint (HBR; 3.07% vs. 4.03%, HR 0.77, 95% CI 0.40-1.48, and non-HBR; 1.41% vs. 1.61%, HR 0.89, 95% CI 0.43-1.84; P for interaction = 0.77), and the major secondary bleeding endpoint (HBR; 0.41% vs. 2.71%, HR 0.15, 95% CI 0.03-0.65, and non-HBR; 0.40% vs. 0.85%, HR 0.48, 95% CI 0.14-1.58; P for interaction = 0.22). In conclusion, the effects of 1-month DAPT for the primary and major secondary endpoints were consistent in HBR and non-HBR patients without any significant interactions. The benefit of 1-month DAPT in reducing major bleeding was numerically greater in HBR patients.Clinical trial registration Short and optimal duration of dual antiplatelet therapy after everolimus-eluting cobalt-chromium stent-2 [STOPDAPT-2]; NCT02619760

Ablation of TSC2 Enhances Insulin Secretion by Increasing the Number of Mitochondria through Activation of mTORC1

) mice. The present study examines the effects of TSC2 ablation on insulin secretion from pancreatic beta cells. mice and TSC2 knockdown insulin 1 (INS-1) insulinoma cells treated with small interfering ribonucleic acid were used to investigate insulin secretion, ATP content and the expression of mitochondrial genes. mice exhibit hyperinsulinemia due to an increase in the number of mitochondria as well as enlargement of individual beta cells via activation of mTORC1.Activation of mTORC1 by TSC2 ablation increases mitochondrial biogenesis and enhances insulin secretion from pancreatic beta cells