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To compare the efficacy and safety of adding low-dose lobeglitazone (0.25 mg/day) or standard-dose lobeglitazone (0.5 mg/day) to patients with type 2 diabetes mellitus (T2DM) with inadequate glucose control on metformin and dipeptidyl peptidase (DPP4) inhibitor therapy.In this phase 4, multicentre, double-blind, randomized controlled, non-inferiority trial, patients with T2DM insufficiently controlled by metformin and DPP4 inhibitor combination therapy were randomized to receive either low-dose or standard-dose lobeglitazone. The primary endpoint was non-inferiority of low-dose lobeglitazone in terms of glycaemic control, expressed as the difference in mean glycated haemoglobin levels at week 24 relative to baseline values and compared with standard-dose lobeglitazone, using 0.5% non-inferiority margin.At week 24, the mean glycated haemoglobin levels were 6.87 ± 0.54% and 6.68 ± 0.46% in low-dose and standard-dose lobeglitazone groups, respectively (p = .031). The between-group difference was 0.18% (95% confidence interval 0.017-0.345), showing non-inferiority of the low-dose lobeglitazone. Mean body weight changes were significantly greater in the standard-dose group (1.36 ± 2.23 kg) than in the low-dose group (0.50 ± 1.85 kg) at week 24. The changes in HOMA-IR, lipid profile and liver enzyme levels showed no significant difference between the groups. Overall treatment-emergent adverse events (including weight gain, oedema and hypoglycaemia) occurred more frequently in the standard-dose group.Adding low-dose lobeglitazone to metformin and DPP4 inhibitor combination resulted in a non-inferior glucose-lowering outcome and fewer adverse events compared with standard-dose lobeglitazone. Therefore, low-dose lobeglitazone might be one option for individualized strategy in patients with T2DM.

Pancreatic β-cells are vulnerable to oxidative stress, which promotes β-cell failure in type 2 diabetes. System χc- is a sodium-independent, cystine/glutamate antiporter that mediates the exchange of extracellular l-cystine and intracellular l-glutamate. The import of l-cystine through this transporter is the rate-limiting step in the glutathione (GSH) biosynthesis pathway that plays a significant role in antioxidative defense. Previously, we reported that 2-deoxy-d-ribose (dRib) induces oxidative damage through GSH depletion in pancreatic β-cells. In the current study, we elucidated the mechanism underlying the oxidative stress-induced β-cell damage. We measured the intracellular l-[14C]cystine uptake, GSH content, reactive oxygen species (ROS) levels, cytotoxicity, and apoptosis in rat insulinoma cell line, RINm5F. Treatment of dRib decreased the intracellular l-[14C]cystine uptake and GSH content and increased the intracellular ROS levels, cytotoxicity, and apoptosis in a time- and dose-dependent manner. Conversely, 2-mercaptoethanol (2-ME), a cystine uptake enhancer, recovered the dRib-induced decrease in l-[14C]cystine uptake, GSH content, and cell viability in a Na+-independent manner. In the case of isolated islets, dRib dose-dependently decreased the intracellular l-[14C]cystine uptake and cell viability; however, dRib-induced cytotoxicity was completely recovered by adding N-acetyl cysteine (NAC). To confirm that system χc- mediates the oxidative stress-induced β-cell damage, we overexpressed xCT (the substrate-specific subunit of system χc-) using a lentiviral vector in RINm5F cells. Overexpression of xCT fully recovered the dRib-induced decrease in l-[14C]cystine uptake and GSH content and prevented the dRib-induced increase in ROS levels, cytotoxicity, and apoptosis. The overexpression of xCT showed a protective effect against dRib-induced oxidative damage in RINm5F cells. Our study showed that dRib depletes intracellular GSH content through inhibition of cystine transport via system χc- in β-cells.

Background: We aimed to investigate the changes in glucagon levels in people with diabetes after the ingestion of a mixed meal and the correlations of variation in glucagon levels with incretin and clinico-biochemical characteristics. Methods: Glucose, C-peptide, glucagon, intact glucagon-like peptide 1 (iGLP-1), and intact glucose-dependent insulinotropic polypeptide (iGIP) were measured in blood samples collected from 317 people with diabetes before and 30 min after the ingestion of a standard mixed meal. The delta (Δ) is the 30-min value minus the basal value. Results: At 30 min after meal ingestion, the glucagon level showed no difference relative to the basal value, whereas glucose, C-peptide, iGLP-1, and iGIP levels showed a significant increase. In univariate analysis, Δglucagon showed not only a strong correlation with HbA1c but also a significant correlation with fasting glucose, Δglucose, and estimated glomerular filtration rate. However, Δglucagon showed no significant correlations with ΔiGLP-1 and ΔiGIP. In the hierarchical multiple regression analysis, HbA1c was the only variable that continued to show the most significant correlation with Δglucagon. Conclusions: People with diabetes showed no suppression of glucagon secretion after meal ingestion. Patients with poorer glycemic control may show greater increase in postprandial glucagon level, and this does not appear to be mediated by incretin.

Metabolic syndrome increases the risk of cardiovascular disease. Recently glucagon-like peptide 1 (GLP-1) agonists proved to be effective in preventing cardiovascular disease (CVD) in patients with type 2 diabetes. We investigated the association of blood incretin levels with metabolic syndrome in patients with type 2 diabetes.This is a cross-sectional study involving 334 people with type 2 diabetes. Intact GLP-1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 min after ingestion of a standard mixed meal. Metabolic syndrome was diagnosed based on the criteria of the International Diabetes Federation.Two hundred twenty-five (69%) of the subjects have metabolic syndrome. The fasting iGLP-1 level was no different between groups. Thirty-min postprandial iGLP-1 was non-significantly lower in the subjects who had metabolic syndrome. Incremental iGLP-1 (ΔiGLP-1, the difference between 30-min postmeal and fasting iGLP-1 levels) was significantly lower in those with metabolic syndrome. There were no significant differences in fasting iGIP, postprandial iGIP, and ΔiGIP between groups. The ΔiGLP-1, but not ΔiGIP levels decreased significantly as the number of metabolic syndrome components increased. In hierarchical logistic regression analysis, the ΔiGLP-1 level was found to be a significant contributor to metabolic syndrome even after adjusting for other covariates.Taken together, the iGLP-1 increment in the 30 min after meal ingestion is inversely associated with metabolic syndrome in patients with type 2 diabetes. This suggests that postmeal iGLP-1 increment could be useful in assessing cardiovascular risk in type 2 diabetes.

Pancreatic β-cells are vulnerable to oxidative stress, which promotes β-cell failure in type 2 diabetes. System χ

Pancreatic β-cells are vulnerable to oxidative stress, which is related to β-cell failure in type 2 diabetes. System x(c)- is a sodium-independent cystine/glutamate antiporter that mediates the exchange of extracelluar L-cystine and intracellular L-glutamate. The import of L-cystine through this transporter is the limiting state of intracellular glutathione (GSH) synthesis that has a major role in defends against oxidative stress. Our previous study reported that 2-deoxy-D-ribose (dRib) induces oxidative damage through GSH depletion in pancreatic β-cells. The aim of the present study was to elucidate the mechanism underlying oxidative stress-induced β-cell damage. We measured intracellular L-[14C] cysteine uptake, GSH content and reactive oxygen species (ROS) levels, cytotoxicity and apoptosis in rat insulinoma cell line (RINm5F cells). Stimulation with dRib dose- and time-dependently decreased intracellular L-[14C] cystine uptake and GSH content and increased intracellular ROS levels, cytotoxicity and apoptosis. The addition of 2-mercaptoethanol (2-ME), a cystine uptake enhancer, sodium-independently recovered the dRib-induced decreases in L-[14C] cystine uptake, GSH content and cell viability. To determine clearly whether system x(c)- deficiency mediate the oxidative stress-induced β-cell damage, we overexpressed xCT, the substrate-specific subunit of the system x(c)-, by using a lentiviral vector in RINm5F cells. Overexpression of xCT fully recovered the dRib-induced decreases in L-[14C] cystine uptake and GSH content and prevented the dRib-induced ROS rises, cytotoxicity and apoptosis. In summary, overexpression of xCT showed protective effects against oxidative damage in RINm5F cells. It suggests that system x(c)- deficiency play a critical role in oxidative stress-induced β-cell damage. Disclosure S. Yoo: None. J. Bae: None. H. Chin: None. G. Koh: None.

We performed this study to identify factors related to intact incretin levels in patients with type 2 diabetes (T2D).We cross-sectionally analyzed 336 patients with T2D. Intact glucagon-like peptide 1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 min after ingestion of a standard mixed meal. The differences between 30 and 0 min iGLP-1 and iGIP levels were indicated as ΔiGLP-1 and ΔiGIP.After ingestion of a mixed meal, iGLP-1 (5.5±3.0 to 10.4±7.0 pmol/L; p

Background We aimed to investigate the effectiveness and safety of adding basal insulin to initiating dipeptidyl peptidase-4 (DPP-4) inhibitor and metformin and/or sulfonylurea (SU) in achieving the target glycosylated hemoglobin (HbA1c) in patients with type 2 diabetes mellitus (T2DM). Methods This was a single-arm, multicenter, 24-week, open-label, phase 4 study in patients with inadequately controlled (HbA1c ≥7.5%) T2DM despite the use of DPP-4 inhibitor and metformin. A total of 108 patients received insulin glargine while continuing oral antidiabetic drugs (OADs). The primary efficacy endpoint was the percentage of subjects achieving HbA1c ≤7.0%. Other glycemic profiles were also evaluated, and the safety endpoints were adverse events (AEs) and hypoglycemia. Results The median HbA1c at baseline (8.9%; range, 7.5% to 11.1%) decreased to 7.6% (5.5% to 11.7%) at 24 weeks. Overall, 31.7% subjects (n=33) achieved the target HbA1c level of ≤7.0%. The mean differences in body weight and fasting plasma glucose were 1.2±3.4 kg and 56.0±49.8 mg/dL, respectively. Hypoglycemia was reported in 36 subjects (33.3%, 112 episodes), all of which were fully recovered. There was no serious AE attributed to insulin glargine. Body weight change was significantly different between SU users and nonusers (1.5±2.5 kg vs. -0.9±6.0 kg, P=0.011). Conclusion The combination add-on therapy of insulin glargine, on metformin and DPP-4 inhibitors with or without SU was safe and efficient in reducing HbA1c levels and thus, is a preferable option in managing T2DM patients exhibiting dysglycemia despite the use of OADs.

Our previous study reported that both oxidative stress and protein glycation were the principal mechanisms underlying 2‑deoxy‑D‑ribose (dRib)‑induced pancreatic β‑cell damage. The aim of the present study was to investigate the effects of captopril on dRib‑induced damage in pancreatic β‑cells, as well as to determine the mechanisms underlying these effects. Treatment with dRib increased the levels of cytotoxicity, apoptosis, and intracellular reactive oxygen species in Syrian hamster insulinoma HIT‑T15 cells; however, pretreatment with captopril significantly inhibited the effects of dRib. The intracellular levels of reduced and oxidized glutathione were depleted following treatment with dRib; however, these levels were restored following HIT‑T15 cell treatment with captopril. In rat islets, dRib stimulation suppressed the mRNA expression levels of insulin, and pancreatic and duodenal homeobox 1, as well as insulin content; however, these effects were dose‑dependently reversed by treatment with captopril. Treatment with buthionine sulfoximine, an inhibitor of intracellular glutathione biosynthesis, inhibited the protective effects of captopril on dRib‑mediated glutathione depletion and cytotoxicity in HIT‑T15 cells. Following incubation with albumin, dRib increased the formation of dicarbonyl and advanced glycation end products. Treatment with captopril did not inhibit the dRib‑induced increase in production of dicarbonyl and advanced glycation end products. In conclusion, treatment with captopril reversed dRib‑induced oxidative damage and suppression of insulin expression in β‑cells. The mechanism underlying the protective effects of captopril may involve increased intracellular glutathione production, rather than protein glycation.

Background: Increased low density lipoprotein cholesterol (LDL-C) level and the presence of metabolic syndrome (MetS) are important risk factors for cardiovascular disease (CVD) in type 2 diabetes mellitus (T2DM). Recent studies demonstrated apolipoprotein B (apoB), a protein mainly located in LDL-C, was an independent predictor of the development of CVD especially in patients with T2DM. The aim of this study was to investigate the relationship between apoB and MetS in T2DM patients. Methods: We analyzed 912 patients with T2DM. Fasting blood samples were taken for glycated hemoglobin, high-sensitivity Creactive protein, total cholesterol, triglyceride (TG), high density lipoprotein cholesterol, LDL-C, and apoB. MetS was defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria. We performed a hierarchical regression analysis with apoB as the dependent variable. Age, sex, the number of components of MetS and LDL-C were entered at model 1, the use of lipid-lowering medications at model 2, and the individual components of MetS were added at model 3. Results: Seventy percent of total subjects had MetS. ApoB level was higher in subjects with than those without MetS (104.5± 53.3 mg/dL vs. 87.7±33.7 mg/dL, P

In patients with type 2 diabetes mellitus (DM), insulin-stimulated glucose uptake is impaired. However, the relationship between serum potassium concentration and insulin resistance is poorly defined. This study aimed to investigate the association between serum potassium concentration and insulin resistance in these patients. Between April 2009 and October 2012, 180 patients with type 2 DM were analyzed. Insulin resistance was estimated using the homeostasis model and assessment (HOMA) index; resistance was defined as an index value of >2. The association between serum potassium concentration and insulin resistance was analyzed using linear regression methods. The incidence of hyperkalemia was also evaluated during follow-up. Mean serum potassium concentration was 4.12 ± 0.47 mEq/l. The median HOMA index score was 2.1 (interquartile range 1.1–3.4). When the patients were compared based on insulin resistance, serum potassium concentration was higher in the patients with insulin resistance compared with the patients without (4.25 ± 0.48 vs. 4.09 ± 0.44 mEq/l, p = 0.015). The variables found to be the determinants of serum potassium concentration included female, renal function, serum sodium level, log aldosterone-to-plasma renin activity ratio, glycosylated hemoglobin, and log HOMA index. Over a mean follow-up period of 2.6 ± 1.1 years, 37 of 180 patients (21 %) experienced episodic hyperkalemia. Patients with insulin resistance experienced episodic hyperkalemia more frequently than those without. Serum potassium concentration is likely to be increased in the patients with poorly controlled type 2 DM with insulin resistance than in those without insulin resistance.

Sialadenitis is a common complication arising from radioactive iodine therapy. F-18-fluoro-2-deoxyglucose positronemission tomography/computed tomography (18F-FDGPET/CT) has been proposed to be useful in detecting not only amalignant lesion but also inflammatory changes. An 18F-FDG uptake pattern can vary according to inflammatorychanges, and the present study reports on a case of late-onset sialadenitis 3 years after the treatment, showing adiffuse and intense 18F-FDGuptakeon 18F-FDGPET/CT. To the best of our knowledge, this is the first report on such an18F-FDG pattern in late-onset sialadenitis after radioiodine therapy.

Background We performed this study to identify factors related to intact incretin levels in patients with type 2 diabetes mellitus (T2DM). Methods We cross-sectionally analyzed 336 patients with T2DM. Intact glucagon-like peptide 1 (iGLP-1) and intact glucose-dependent insulinotropic polypeptide (iGIP) levels were measured in a fasted state and 30 minutes after ingestion of a standard mixed meal. The differences between 30 and 0 minute iGLP-1 and iGIP levels were indicated as ΔiGLP-1 and ΔiGIP. Results In simple correlation analyses, fasting iGLP-1 was positively correlated with glucose, C-peptide, creatinine, and triglyceride levels, and negatively correlated with estimated glomerular filtration rate. ΔiGLP-1 was positively correlated only with ΔC-peptide levels. Fasting iGIP showed positive correlations with glycosylated hemoglobin (HbA1c) and fasting glucose levels, and negative correlations with ΔC-peptide levels. ΔiGIP was negatively correlated with diabetes duration and HbA1c levels, and positively correlated with Δglucose and ΔC-peptide levels. In multivariate analyses adjusting for age, sex, and covariates, fasting iGLP-1 levels were significantly related to fasting glucose levels, ΔiGLP-1 levels were positively related to ΔC-peptide levels, fasting iGIP levels were related to fasting C-peptide levels, and ΔiGIP levels were positively related to ΔC-peptide and Δglucose levels. Conclusion Taken together, intact incretin levels are primarily related to C-peptide and glucose levels. This result suggests that glycemia and insulin secretion are the main factors associated with intact incretin levels in T2DM patients.

Jeju water is the groundwater of Jeju Island, a volcanic island located in Republic of Korea. We investigated whether Jeju water improved glycemic control in patients with diabetes. This was a 12-week single-center, double-blind, randomized, and controlled trial. The subjects daily drank a liter of one of three kinds of water: two Jeju waters (S1 and S2) and Seoul tap water (SS). The primary outcome was the proportion of patients in the per-protocol (PP) population achieving glycated hemoglobin (HbA1c)<7.0% at week 12. In total, 196 patients were randomized and analyzed in the intention-to-treat (ITT) population (66 consuming S1, 63 consuming S2, and 67 consuming SS); 146 patients were considered in the PP population. There were no significant differences in the primary outcomes of the groups consuming S1, S2, or SS. However, the percentage of patients achieving HbA1c<8% was significantly higher in the S2 group than in the SS group. In the ITT population, the 12-week HbA1c and fructosamine levels were lower in the S1 group than in the SS group and the 4-, 8-, and 12-week fructosamine levels were lower in the S2 group than in the SS group. Although we failed to achieve the primary outcome, it is possible that the Jeju waters improve glycemic control compared with the Seoul tap water in diabetic patients.

Background This study aimed to investigate whether stimulated C-peptide is associated with microvascular complications in type 2 diabetes mellitus (DM). Methods A cross-sectional study was conducted in 192 type 2 diabetic patients. Plasma basal C-peptide and stimulated C-peptide were measured before and 6 minutes after intravenous injection of 1 mg glucagon. The relationship between C-peptide and microvascular complications was statistically analyzed. Results In patients with retinopathy, basal C-peptide was 1.9±1.2 ng/mL, and stimulated C-peptide was 2.7±1.6 ng/mL; values were significantly lower compared with patients without retinopathy (P=0.031 and P=0.002, respectively). In patients with nephropathy, basal C-peptide was 1.6±0.9 ng/mL, and stimulated C-peptide was 2.8±1.6 ng/mL; values were significantly lower than those recorded in patients without nephropathy (P=0.020 and P=0.026, respectively). Stimulated C-peptide level was associated with increased prevalence of microvascular complications. Age-, DM duration-, and hemoglobin A1c-adjusted odds ratios for retinopathy in stimulated C-peptide value were 4.18 (95% confidence interval [CI], 1.40 to 12.51) and 3.35 (95% CI, 1.09 to 10.25), respectively. The multiple regression analysis between nephropathy and C-peptide showed that stimulated C-peptide was statistically correlated with nephropathy (P=0.03). Conclusion In patients with type 2 diabetes, the glucagon stimulation test was a relatively simple method of short duration for stimulating C-peptide response. Stimulated C-peptide values were associated with microvascular complications to a greater extent than basal C-peptides.

Hashimoto thyroiditis (HT) is an autoimmune thyroid disorder that usually presents as a diffuse, nontender goiter, whereas subacute thyroiditis (SAT) is an uncommon disease that is characterized by tender thyroid enlargement, transient thyrotoxicosis, and an elevated erythrocyte sedimentation rate (ESR). Very rarely, patients with HT can present with painful, tender goiter or fever, a mimic of SAT. We report a case of painful HT in a 68-year-old woman who presented with pain and tenderness in a chronic goiter. Her ESR was definitely elevated and her thyroid laboratory tests suggested subclinical hypothyroidism of autoimmune origin. (99m)Tc pertechnetate uptake was markedly decreased. Fine needle aspiration biopsy revealed reactive and polymorphous lymphoid cells and occasional epithelial cells with Hurthle cell changes. Her clinical symptoms showed a dramatic response to glucocorticoid treatment. She became hypothyroid finally and is now on levothyroxine therapy.

Resveratrol (RSV) has various metabolic effects, especially with relatively high-dose therapy. However, the ability of RSV to modulate insulin signaling has not been completely evaluated. Here, we determined whether RSV alters insulin signaling in insulin-responsive cells and tissues. The effects of RSV on insulin signaling in 3T3-L1 adipocytes under both insulin-sensitive and insulin-resistant states and in insulin-sensitive tissues of high fat-fed diet-induced obese (DIO) mice were investigated. Insulin-stimulated insulin receptor substrate-1 tyrosine phosphorylation (Y612) was suppressed in RSV-treated adipocytes compared with untreated adipocytes, as was the insulin-stimulated Akt phosphorylation (Ser473). However, under an insulin-resistant condition that was made by incubating 3T3-L1 adipocytes in the conditioned medium from lipopolysaccharide-stimulated LAW264.7 cells, RSV reduced inducible nitric oxide synthase expression and IκBα protein degradation and improved insulin-stimulated Akt phosphorylation (Ser473). In DIO mice, relatively low-dose RSV (30 mg/kg daily for 2 weeks) therapy lowered fasting blood glucose level and serum insulin, increased hepatic glycogen content, and ameliorated fatty liver without change in body weight. The insulin-stimulated Akt phosphorylation was decreased in the liver and white adipose tissue of DIO mice, but it was completely normalized by RSV treatment. However, in the skeletal muscle of DIO mice, insulin signaling was not improved by RSV treatment, whereas the phosphorylation of adenosine monophosphate-activated protein kinase α (Thr172) was improved by it. Our results show that RSV enhances insulin action only under insulin-resistant conditions and suggest that the effect of RSV may depend on the type of tissue being targeted and its metabolic status.

Background Recent studies have revealed that C-peptide induces smooth muscle cell proliferation and causes human atherosclerotic lesions in diabetic patients. The present study was designed to examine whether the basal C-peptide levels correlate with cardiovascular risk in type 2 diabetes mellitus (T2DM) patients. Methods Data was obtained from 467 patients with T2DM from two institutions who were followed for four years. The medical findings of all patients were reviewed, and patients with creatinine >1.4 mg/dL, any inflammation or infection, hepatitis, or type 1 DM were excluded. The relationships between basal C-peptide and other clinical values were statistically analyzed. Results A simple correlation was found between basal C-peptide and components of metabolic syndrome (MS). Statistically basal C-peptide levels were significantly higher than the three different MS criteria used in the present study, the Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program's (NCEP's), World Health Organization (WHO), and the International Diabetes Federation (IDF) criteria (NCEP-ATP III, P=0.001; IDF, P

The management of hyperglycemia, the hallmark metabolic abnormality associated with type 2 diabetes, has taken center stage in the treatment of diabetes. The development of new classes of blood glucose-lowering medications to supplement the older therapies has increased the number of treatment options available for type 2 diabetes. The increased number of choices available to practitioners and patients has heightened uncertainty regarding the most appropriate means of treating this widespread disease. The ADA/EASD consensus algorithm for the medical management of type 2 diabetes was published in January 2009. I introduced the consensus approach to the management of hyperglycemia to help guide health care providers in choosing the most appropriate interventions for their patients with type 2 diabetes.

Exenatide is the first in a new class of compounds, which possess similar activity to the naturally-occurring hormone glucagon-like peptide-1 (GLP-1. In three phase Ⅲ trials in patients with type 2 diabetes mellitus (T2DM). who have Inadequate glycaemic control despite receiving treatment with metformin and/ or sulfonylurea, the addition of exenatide twice daily significantly reduced glycated haemoglobin ( ≤ 1 %), and fasting and postprandial plasma glucose and was associated with progressive and significant bodyweight reduction from baseline for up to 2 years, Nausea (about 40%) was the most commonly reported adverse event in the combined exenatide groups. The addition of exenatide also improved glycemic control in a small population with T2DM receiving thiazolidinedione. The glycaemic control with exenatide was similar to that achieved with insulin glargine or biphasic insulin aspart. However， the insulin doses were well below doses used in recent studies. In a head-to-head clinical trial， exenatide once-weekly caused greater improvements in glycemic control and was better tolerated than exenatide twice daily. On the basis of the data, adjunctive therapy with exenatide is a valuable therapeutic option in obese patients with T2DM requiring moderate improvements in glycaemic control despite treatment with metformin and/or a sulfonylurea, In addition, exenatide once-weekly is a promising development candidate for the treatment of T2DM.

2-Deoxy- d -ribose (dRib) is known to induce oxidative damage and apoptosis by depleting GSH content in several types of cells. However, little is known about how dRib depletes intracellular GSH content. We hypothesized that dRib would deplete GSH content through inhibition of cystine uptake via system χc-. HIT-T15 cells were incubated with various concentrations of dRib, 2-mercaptoethanol (2-ME), Sulfasalazine (SASP), and homocysteic acid (HCA). We measured intracellular uptake of l -[14C]cystine, GSH content, and cell viability. Stimulation with dRib dose- and time-dependently decreases intracellular l -[14C]cystine uptake and GSH content. The addition of 2-ME, a cystine uptake enhancer, fully recovered the dRib-induced decreases in l -[14C]cystine uptake, GSH content, and cell viability. The 2-ME promoted the l -[14C]cystine uptake even in the absence of extracellular Na+, probably suggesting the involvement of the system χc-. SASP and HCA, system χc- inhibitors, significantly reduced l -[14C]cystine uptake and GSH content like dRib did, and 2-ME also restored the reductions. These findings suggest that dRib depletes intracellular GSH content through inhibition of cystine transport, and this inhibition may be mediated by system χc-. Additional experiments using a gene overexpression technique is necessary to further clarify the mechanism.

Case Kaposi’s sarcoma (KS) is a malignant vascular tumor that occurs commonly in patients with acquired immunodeficiency syndrome. KS associated with Cushing’s syndrome (CS) is unusual, especially in endogenous CS. Here, we report a case of KS associated with glucocorticoid-replacement therapy after surgical treatment for adrenal CS. A 70-year-old man presented with symptoms and signs of CS with a left adrenal mass. Adrenal CS was confirmed by biochemical studies. After left adrenalectomy, he took oral prednisolone (15 mg/day) to prevent adrenal insufficiency. Ten weeks later, numerous raised purple plaques on the lower extremities were newly detected. The biopsy findings were compatible with KS, but anti-HIV antibodies were negative. After withdrawal of glucocorticoid therapy, the skin lesions regressed completely. Conclusion In this case, KS developed after the use of exogenous corticosteroid but not during endogenous hypercortisolism. This finding suggests that endogenous and exogenous corticosteroid play different roles in the development of KS.

Endothelial cell apoptosis has been postulated as the initial trigger of the progression of microvascular disease in patients with diabetes mellitus. To investigate the role of Scutellariae radix extract, we examined its effect on the endothelial cell proliferation using the [3H]-thymidine incorporation method. Scutellariae radix extract significantly stimulated endothelial cell proliferation in a dose-dependent manner. We focused on the protective action of Scutellariae radix extract on the endothelial cell apoptosis induced by high glucose concentrations. Determination of endothelial cell apoptosis was performed using DNA gel electrophoresis, terminal deoxynuclotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, and an ELISA kit. Exposure of vascular endothelial cell to high glucose (16.7 mM) for 72 h resulted in a significant increase in apoptosis, compared with the normal glucose concentrations (5.5 mM). Scutellariae radix extract inhibited high glucose-induced endothelial cell apoptosis. This result suggests that Scutellariae radix extract may contribute to antiapoptotic action against vascular endothelial cells, resulting in a beneficial effect in preventing diabetes-associated microvascular complications.

OBJECTIVE We aimed to evaluate the association between hypoglycemia at admission and 30-day mortality in patients with acute myocardial infarction (AMI) and to determine whether these associations differed according to diabetes-control status in AMI patients with diabetes. RESEARCH DESIGN AND METHODS We analyzed the prognostic significance of hypoglycemia and hyperglycemia in 34,943 AMI patients with or without type 2 diabetes from two AMI registries: the Korea Acute Myocardial Infarction Registry (KAMIR) and the Korea Working Group on Myocardial Infarction (KorMI). RESULTS The patients were divided into five groups according to serum-glucose levels at admission: CONCLUSIONS These data suggest that hypoglycemia at admission affects clinical outcomes differently in AMI patients with type 2 diabetes depending on the diabetes-control status.

We investigated whether α-lipoic acid (LA) could prevent 2-deoxy-D-ribose (dRib)-induced oxidative damage and suppression of insulin expression in pancreatic β-cells. Stimulation with 50 mM dRib elevated cytotoxicity, apoptosis and intracellular reactive oxygen species (ROS) levels in HIT-T15 cells, but pretreatment with LA significantly reversed the dRib-induced changes. LA directly scavenged hydroxyl radicals generated by a Fenton reaction. Intracellular reduced glutathione (GSH) and oxidized glutathione (GSSG) were depleted by stimulation with dRib but levels were restored by addition of LA to HIT-T15 cells. However, the GSH/GSSG ratio was unchanged by LA treatment. In rat islets, stimulation with 10 mM dRib for 6 h suppressed expression of insulin and pancreatic and duodenal homeobox 1 mRNA and decreased insulin content, but these were dose-dependently reversed when LA was added. Treatment with l-buthionine-sulfoximine, an inhibitor of intracellular glutathione biosynthesis, completely abolished the protective effects of LA on dRib-mediated glutathione depletion and cytotoxicity in HIT-T15 cells. In summary, LA reversed the dRib-induced oxidative damage and suppression of insulin expression in β-cells. Enhanced intracellular total glutathione production, rather than the scavenging of ROS, is possibly the mechanism for the protective effect of LA.

Context: Dipeptidyl peptidase 4 (CD26/DPP4) is expressed on blood T cells and also circulates in a soluble form (sCD26/DPP4). Objective: We aimed to evaluate blood T cell and circulating CD26/DPP4 and its association with metabolic parameters in patients with type 2 diabetes mellitus (T2DM). Designs: We measured CD26/DPP4 expression (percentage of CD26+ cells using flow cytometry) on CD4+ and CD8+ T cells, serum CD26/DPP4 level and activity, and various metabolic parameters in T2DM patients not on DPP4 inhibitor therapy (n = 148). Nondiabetic subjects (n = 50) were included as a control group. Results: Compared with the healthy controls, CD26/DPP4 expression on CD4+ T cells and CD8+ T cells was higher in T2DM patients. Serum CD26/DPP4 levels and enzymatic activities were also higher in patients with T2DM than in the control group only when metformin and/or thiazolidinedione-treated T2DM patients were excluded; metformin and/or thiazolidinedione-treated T2DM patients had lower values compared with other T2DM patients. Various parameters in T2DM patients were related to CD26/DPP4 expression on the T cells (hemoglobin A1c), serum sCD26/DPP4 (hemoglobin A1c and insulin resistance assessed by updated homeostasis model assessment), and serum CD26/DPP4 activity (insulin resistance assessed by updated homeostasis model assessment, γ-glutamyl transferase, and alanine aminotransferase) by multivariate analyses. After active glucose control for 12 weeks in drug-naive T2DM patients (n = 50), CD26/DPP4 expression on blood T cells was significantly decreased. Conclusions: Our results suggest that the CD26/DPP4 level on blood T cells was associated with glucose control status in patients with T2DM.

We compared the effects of gliclazide, an antidiabetic agent with antioxidant properties, andN-acetyl-L-cysteine (NAC), a glutathione precursor, in protecting against 2-deoxy-D-ribose- (dRib-) induced oxidative damage in HIT-T15 cells. Using trypan blue staining and flow cytometry with annexin V/PI staining, gliclazide treatment slightly reversed dRib-induced cell death and apoptosis, and NAC treatment markedly reduced both measures. Likewise, flow cytometry using DHR 123 staining showed that the levels of dRib-induced reactive oxygen species (ROS) were partially suppressed by gliclazide and completely inhibited by NAC. Using electron spin resonance spectrometry, gliclazide and NAC scavenged hydroxyl radicals generated by Fenton reaction to a similar degree in a cell-free system. NAC, but not gliclazide, completely restored the intracellular glutathione depleted by dRib using monochlorobimane fluorescence and glutathione assays. Thus, gliclazide treatment suppressed dRib-induced oxidative damage in HIT-T15 cells less than NAC did because gliclazide did not restore the intracellular glutathione content as effectively as NAC. In addition, the elevation of intracellular glutathione rather than free radical scavenging might be an important mechanism for protecting against dRib-induced oxidative damage in aβ-cell line.