Comparison of the effects on glycaemic control and β-cell function in newly diagnosed type 2 diabetes patients of treatment with exenatide, insulin or pioglitazone: a multicentre randomized parallel-group trial (the CONFIDENCE study)

Comparison of changes in adipokine and inflammatory cytokine levels in patients with newly diagnosed type 2 diabetes treated with exenatide, insulin, or pioglitazone: A post-hoc study of the CONFIDENCE trial

Background

Adipokines and inflammatory cytokines (ADICs) play important roles in type 2 diabetes mellitus (T2DM). This study aimed to compare the changes of ADIC levels (ΔADICs) in patients with newly diagnosed T2DM treated with different antihyperglycemic agents, and further investigate the impact of these changes on metabolic indices, β-cell function and insulin resistance (IR).

Methods

Four hundred and sixteen patients with newly diagnosed T2DM from 25 centers in China randomly received 48-week intervention with exenatide, insulin or pioglitazone. Anthropometric and laboratory data, indices of β-cell function and IR, and levels of AIDCs, including interleukin-1 beta (IL-1β), interferon-gamma (IFN-γ), leptin, and fibroblast growth factor 21 (FGF21) were detected at baseline and the end of the study.

Results

In total, 281 participants (68 % male, age: 50.3 ± 9.4 years) completed the study. After 48- week treatment, IL-1β and IFN-γ were significantly decreased with exenatide treatment (P < 0.001 and P = 0.001, respectively), but increased with insulin (P = 0.009 and P = 0.026, respectively). However, pioglitazone treatment had no impact on ADICs. No significant change in leptin or FGF21 was detected with any of the treatments. After adjustment for baseline values and changes of body weight, waist and HbA1c, the between-group differences were found in ΔIL-1β (exenatide vs. insulin: P = 0.048; and exenatide vs. pioglitazone: P = 0.003, respectively) and ΔIFN-γ (exenatide vs. insulin: P = 0.049; and exenatide vs. pioglitazone: P < 0.001, respectively). Multiple linear regression analysis indicated that Δweight was associated with ΔIL-1β (β = 0.753; 95 % CI, 0.137-1.369; P = 0.017). After adjusting for treatment effects, Δweight was also be correlated with ΔFGF21 (β = 1.097; 95%CI, 0.250-1.944; P = 0.012); furthermore, ΔHOMA-IR was correlated with Δleptin (β = 0.078; 95%CI, 0.008-0.147; P = 0.029) as well. However, ΔHOMA-IR was not significantly associated with ΔIL-1β after adjusting for treatment effects (P = 0.513).

Conclusion

Exenatide treatment led to significant changes of inflammatory cytokines levels (IL-1β and IFN-γ), but not adipokines (leptin and FGF21), in newly diagnosed T2DM patients. The exenatide-mediated improvement in weight and IR may be associated with a decrease in inflammatory cytokine levels.

Comparative effectiveness of multiple different treatment regimens for nonalcoholic fatty liver disease with type 2 diabetes mellitus: a systematic review and Bayesian network meta-analysis of randomised controlled trials

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are closely related and mutually contribute to the disease's development. There are many treatment options available to patients. We provide a comprehensive overview of the evidence on the treatment effects of several potential interventions for NAFLD with T2DM.

METHODS

This systematic review and network meta-analysis included searches of PubMed, Embase, Cochrane Library, and Web of Science from inception to June 30, 2023, for randomised controlled trials of treatment of NAFLD with T2DM. We performed Bayesian network meta-analyses to summarise effect estimates of comparisons between interventions. We applied the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) frameworks to rate all comparative outcomes' certainty in effect estimates, categorise interventions, and present the findings. This study was registered with PROSPERO, CRD42022342373.

RESULTS

Four thousand three hundred and sixty-nine records were retrieved from the database and other methods, of which 24 records were eligible for studies enrolling 1589 participants. Eight clinical indicators and 14 interventions were finally in focus. Referring to the lower surface under the cumulative ranking curves (SUCRA) and the league matrix table, exenatide and liraglutide, which are also glucagon-like peptide-1 receptor agonists (GLP-1RAs), showed excellent potential to reduce liver fat content, control glycemia, reduce body weight, and improve liver function and insulin resistance. Exenatide was more effective in reducing glycated haemoglobin (HbA1c) (mean difference (MD) 0.32, 95%CI 0.12 to 0.52), lowering BMI (MD 0.81, 95%CI 0.18 to 1.45), and lowering alanine transaminase (ALT) (MD 10.96, 95%CI 5.27 to 16.66) compared to liraglutide. However, this evidence was assessed as low certainty. Omega-3 was the only intervention that did not have a tendency to lower HbA1c, with standard-treatment (STA-TRE) as reference (MD - 0.17, 95%CI - 0.42 to 0.07). Glimepiride is the only intervention that causes an increase in ALT levels, with standard-treatment (STA-TRE) as reference (MD - 11.72, 95%CI - 17.82 to - 5.57). Based on the available evidence, the treatment effects of pioglitazone, dapagliflozin, and liraglutide have a high degree of confidence.

CONCLUSIONS

The high confidence mandates the confident application of these findings as guides for clinical practice. Dapagliflozin and pioglitazone are used for glycaemic control in patients with NAFLD combined with T2DM, and liraglutide is used for weight loss therapy in patients with abdominal obesity. The available evidence does not demonstrate the credibility of the effectiveness of other interventions in reducing liver fat content, visceral fat area, ALT, and insulin resistance. Future studies should focus on the clinical application of GLP-1Ras and the long-term prognosis of patients.

Beta-cell function in type 2 diabetes (T2DM): Can it be preserved or enhanced?

Type 2 diabetes (T2DM) is a complex metabolic disorder manifested by hyperglycemia, insulin resistance, and deteriorating beta-cell function. A way to prevent progression of the disease might be to enhance beta-cell function and insulin secretion. However, most previous studies examined beta-cell function while patients were using glycemia-lowering agents without an adequate period off medications (washout). In the present review we focus on studies with a washout period. We performed a literature search (2010 to June 2021) using beta-cell function and enhancement. The evidence shows that beta-cell function can be enhanced. Bariatric surgery and very low calorie diets show improvement in beta-cell function in many individuals. In addition, use of glucagon-like peptide-1 receptor agonists for prolonged periods (3 years or more) can also lead to improvement of beta-cell function. Further research is needed to understand the mechanisms leading to improved beta-cell function and identify agents that could enhance beta-cell function in patients with T2DM.

Data-driven subgroups of newly diagnosed type 2 diabetes and the relationship with cardiovascular diseases at genetic and clinical levels in Chinese adults

BACKGROUND

To subgroup Chinese patients with newly diagnosed type 2 diabetes (T2D) by K-means cluster analysis on clinical indicators, and to explore whether these subgroups represent different genetic features and calculated cardiovascular risks.

METHODS

The K-means clustering analysis was performed on two cohorts (n = 590 and 392), both consisting of Chinese participants with newly diagnosed T2D. To assess genetic risks, multiple polygenic risk scores (PRSs) and mitochondrial DNA copy numbers (mtDNA-CN) were calculated for all participants. Furthermore, Framingham risk scores (FRS) of cardiovascular diseases in two cohorts were also calculated to verify the genetic risks.

RESULTS

Four clusters were identified including the mild age-related diabetes (MARD)(35.08%), mild obesity-related diabetes (MOD) (34.41%), severe autoimmune diabetes (SAID) 19.15%, and severe insulin-resistant diabetes (SIRD) 11.36% subgroups in the MARCH (metformin, and acarbose in Chinese patients as the initial hypoglycemic treatment) cohort. There was a significant difference in PRS for cardiovascular diseases (CVD) across four subgroups in the MARCH cohort (p < 0.05). Compared with the SIDD and SIRD subgroups, patients in the MOD subgroup had a relatively lower PRS for CVD (p < 0.05) in the MARCH cohort. Females had a higher PRS compared to males, with no significant difference in FRS across the four clusters. The MOD subgroup had a significantly lower FRS which was consistent with the results of PRS. Similar results of PRS and FRS were also replicated in the CONFIDENCE (comparison of glycemic control and b-cell function among newly diagnosed patients with type 2 diabetes treated with exenatide, insulin or pioglitazone) cohort.

CONCLUSION

There are different CVD risks in diabetic subgroups based on clinical and genetic evidence which may promote precision medicine.

GLP-1RAs caused gastrointestinal adverse reactions of drug withdrawal: a system review and network meta-analysis

Background

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) significantly reduce postprandial blood glucose, inhibit appetite, and delay gastrointestinal emptying. However, it is controversial that some patients are intolerant to GLP-1RAs.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched for randomized controlled trials (RCTs) using GLP-1RAs with documented withdrawal due to gastrointestinal adverse reactions (GI AEs) from their inception to September 28, 2022. After extracting the information incorporated into the studies, a random-effects network meta-analysis was performed within a frequentist framework.

Results

64 RCTs were finally enrolled, which included six major categories of the GLP-1RA. The sample size of the GLP-1RAs treatment group was 16,783 cases. The risk of intolerable gastrointestinal adverse reactions of Liraglutide and Semaglutide was higher than that of Dulaglutide. Meanwhile, the higher the dose of the same GLP-1RA preparation, the more likely to cause these adverse reactions. These intolerable GI AEs were not significantly related to drug homology or formulations and may be related to the degree of suppression of the appetite center.

Conclusion

Dulaglutide caused the lowest intolerable GI AEs, while Liraglutide and Semaglutide were the highest. For Semaglutide, the higher the dose, the more likely it is to drive GI AEs. Meanwhile, the risk of these GI AEs is independent of the different formulations of the drug. All these findings can effectively guide individualized treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022359346, identifier CRD42022359346.

EFFECT OF AEROBIC EXERCISE ON LIMB MOTOR FUNCTION IN DIABETIC PATIENTS

ABSTRACT Introduction: Gestational Diabetes is a group of metabolic disorders that result in glucose intolerance during pregnancy. Among the range of treatments are diet, continuous use of medication, and psychological monitoring. Since it is a multidisciplinary treatment, a proper protocol is vital for a favorable outcome. In addition, there are questions about the benefits of physical activity as a complementary therapy. Objective: To verify the impact of adding exercise to the hospital protocol for patients with gestational diabetes, both on the risks of type 2 diabetes in pregnant women and on the obesity of their offspring. Methods: Sixty pregnant women diagnosed with Gestational Diabetes were randomly divided into control and intervention groups. Both groups received specific treatment and intervention, and the experimental group practiced controlled moderate-intensity physical activity (125-146bpm). Morning blood samples were collected from both groups to check fasting glucose and insulin levels, indicators of lipid metabolism, low and high-density lipoprotein cholesterol, apolipoprotein B. The Brog scale measured the fatigue level. In addition, the premature rupture of membranes, postpartum hemorrhage, neonatal asphyxia, macrosomia, and others was checked. Results: The peripheral blood total cholesterol levels were 5.93, 5. 38, low-density lipoprotein cholesterol levels were 2.95 before versus 2.64 after, and apolipoprotein B levels were 1.84 versus 1.59 in the control group, high-density lipoprotein cholesterol content increased from 1.74 to 1.88, blood cholesterol, and apolipoprotein B levels after the intervention in the experimental group were lower than those in the control group, with an elevation of high-density lipoprotein cholesterol. Conclusion: Aerobic exercise proved to be more appropriate for patients with gestational diabetes in the later stages of pregnancy and may also be adapted for bedridden patients refractory to traditional drugs. Evidence Level II; Therapeutic Studies - Investigating the result.

KCNQ1 variant rs163184 is a potential biomarker of glycemic response to exenatide

Aim: To examine the association between variant rs163184 in the type 2 diabetes mellitus (T2DM) susceptibility gene KCNQ1 and exenatide glycemic response in the Chinese population. Patients & methods: We included 100 T2DM patients from the CONFIDENCE study and investigated the association between rs163184 and glycemic response to exenatide, by using a multivariate linear model with adjustment for baseline glucose status and other covariates. Results: The G allele of rs163184 was associated with a 0.34% (p = 0.016) lower glycosylated hemoglobin reduction after 48 weeks of exenatide treatment. Similar significant associations were observed when glycemic response to exenatide was evaluated with fasting blood glucose or postprandial blood glucose reduction. Conclusion: We found that rs163184 in the gene KCNQ1 was associated with reduced glycemic response to exenatide in T2DM patients. The effect size observed in this study was large enough to be considered clinically relevant in stratified medicine.

Exendin-4 and eldecalcitol synergistically promote osteogenic differentiation of bone marrow mesenchymal stem cells through M2 macrophages polarization via PI3K/AKT pathway

Background

The incidence of diabetic osteoporosis is increasing. This article evaluates the effect of combination treatment with the hypoglycemic drug exendin-4 (Ex-4) and the vitamin D analog eldecalcitol (ED-71) on improving diabetic osteoporosis and explores the relevant mechanism of action.

Method

Micro-CT, HE staining, immunohistochemistry, qPCR and ELISA were used to evaluate the impact of Ex-4 and ED-71 on bone formation and macrophage polarization in a mouse model of diabetic osteoporosis in vivo. Immunofluorescence, flow cytometry and qPCR were used to characterize the polarization type of macrophages treated with Ex-4 and ED-71 in vitro. A co-culture system of BMSCs and macrophages was established. Subsequently, crystal violet staining, alkaline phosphatase staining and alizarin red staining were used to evaluate the migration and osteogenesis differentiation of BMSCs.

Results

Ex-4 combined with ED-71 significantly reduced blood glucose levels and enhanced bone formation in mice with diabetic osteoporosis. In addition, Ex-4 synergized with ED-71 to induce the polarization of macrophages into M2 through the PI3K/AKT pathway. Macrophages treated with the combination of Ex-4 and ED-71 can significantly induce the osteogenic differentiation of BMSCs.

Conclusion

Ex-4 synergized with ED-71 to reduce blood glucose levels significantly. And this combination therapy can synergistically induce osteogenic differentiation of BMSCs by promoting M2 macrophages polarization, thereby improving diabetic osteoporosis. Therefore, the combination of Ex-4 and ED-71 may be a new strategy for the treatment of diabetic osteoporosis.

Effects of PPARD gene variants on the therapeutic responses to exenatide in chinese patients with type 2 diabetes mellitus

BACKGROUND

Exenatide is a GLP-1R agonist that often exhibits considerable interindividual variability in therapeutic efficacy. However, there is no evidence about the impact of genetic variants in the PPARD on the therapeutic efficacy of exenatide. This research was aimed to explore the influence of PPARD gene polymorphism on the therapeutic effect of exenatide, and to identify the potential mechanism futher.

METHODS

A total of 300 patients with T2DM and 200 control subjects were enrolled to identify PPARD rs2016520 and rs3777744 genotypes. A prospective clinical study was used to collect clinical indicators and peripheral blood of T2DM patients treated with exenatide monotherapy for 6 months. The SNaPshot method was used to identify PPARD rs2016520 and rs3777744 genotypes, and then we performed correlation analysis between PPARD gene variants and the efficacy of exenatide, and conducted multiple linear regression analysis of factors affecting the therapeutic effect of exenatide. HepG2 cells were incubated with exenatide in the absence or presence of a PPARδ agonist or the siPPARδ plasmid, after which the levels of GLP-1R and the ratio of glucose uptake were determined.

RESULTS

After 6 months exenatide monotherapy, we observed that homeostasis model assessment for insulin resistance (HOMA-IR) levels of the subjects with at least one C allele of the PPARD rs2016520 were significantly lower than those with the TT genotype, which suggested that the PPARD rs2016520 TT genotype conferred the poor exenatide response through a reduction of insulin resistance, as measured by HOMA-IR. The carriers of G alleles at rs3777744 exhibited higher levels of in waist to hip ratio (WHR), fasting plasma glucose (FPG), hemoglobin A1c (HbA1c) and HOMA-IR compared to individuals with the AA genotype following 6 months of exenatide treatment, potentially accounting for the lower failure rate of exenatide therapy among the AA homozygotes. In an insulin resistant HepG2 cell model, the PPARδ agonists enhanced exenatide efficacy on insulin resistance, with the expression of GLP-1R being up-regulated markedly.

CONCLUSION

These data suggest that the PPARD rs2016520 and rs3777744 polymorphisms are associated with exenatide monotherapy efficacy, due to the pivotal role of PPARδ in regulating insulin resistance through affecting the expression of GLP-1R. This study was registered in the Chinese Clinical Trial Register (No. ChiCTR-CCC13003536).

The Changes of Lipidomic Profiles Reveal Therapeutic Effects of Exenatide in Patients With Type 2 Diabetes

OBJECTIVE

Exenatide has been demonstrated beneficial effects on patients with type 2 diabetes mellitus (T2DM) regarding lipid metabolism. However, the potential mechanism remains unclear. We used a lipidomic approach to evaluate lipid changes in response to treatment with exenatide in T2DM patients.

METHODS

Serum lipidomic profiles of 35 newly diagnosed T2DM patients (before and after exenatide treatment) and 20 age-matched healthy controls were analyzed by ultrahigh-performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry.

RESULTS

A total of 45 lipid species including sphingomyelins (SMs), ceramides (CERs), lysophosphatidylcholines (LPCs), phosphatidylethanolamines (PEs), lysophosphatidylethanolamines (LPEs) and phosphatidylcholines (PCs) were identified in all participants. Compared to the healthy controls, 13 lipid species [SM (d18:1/18:0, d18:1/18:1), Cer (d18:1/18:0, d18:1/16:0, d18:1/20:0, d18:1/24:1), LPC (15:0, 16:0, 17:0), PC (19:0/19:0), LPE (18:0) and PE (16:0/22:6, 18:0/22:6)] were markedly increased in the T2DM group, while PE (17:0/17:0) and PC (18:1/18:0) were decreased (P < 0.05). The serum SM (d18:1/18:0, d18:1/18:1), LPC (16:0), and LPE (18:0) were significantly decreased after exenatide treatment, which was accompanied by the amelioration of lipids and glycemic parameters (TC, LDL-C, ApoA-I, FCP and HbA_1c) in T2DM patients. The chord diagrams showed distinct correlation patterns between lipid classes and subclasses among healthy controls, T2DM patients before and after exenatide treatment.

CONCLUSION

Our results revealed that the therapeutic benefits of exenatide on T2DM might be involved in the improved lipid metabolism, especially SM, LPC, and LPE.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, identifier NCT03297879.

Islet Function and Insulin Sensitivity in Latent Autoimmune Diabetes in Adults Taking Sitagliptin: A Randomized Trial

CONTEXT

The long-term effects of dipeptidyl peptidase-4 inhibitors on β-cell function and insulin sensitivity in latent autoimmune diabetes in adults (LADA) are unclear.

OBJECTIVE

To investigate the effects of sitagliptin on β-cell function and insulin sensitivity in LADA patients receiving insulin.

DESIGN AND SETTING

A randomized controlled trial at the Second Xiangya Hospital.

METHODS

Fifty-one patients with LADA were randomized to sitagliptin + insulin (SITA) group or insulin alone (CONT) group for 24 months.

MAIN OUTCOME MEASURES

Fasting C-peptide (FCP), 2-hour postprandial C-peptide (2hCP) during mixed-meal tolerance test, △CP (2hCP - FCP), and updated homeostatic model assessment of β-cell function (HOMA2-B) were determined every 6 months. In 12 subjects, hyperglycemic clamp and hyperinsulinemic euglycemic clamp (HEC) tests were further conducted at 12-month intervals.

RESULTS

During the 24-month follow-up, there were no significant changes in β-cell function in the SITA group, whereas the levels of 2hCP and △CP in the CONT group were reduced at 24 months. Meanwhile, the changes in HOMA2-B from baseline were larger in the SITA group than in the CONT group. At 24 months, first-phase insulin secretion was improved in the SITA group by hyperglycemia clamp, which was higher than in the CONT group (P < .001), while glucose metabolized (M), insulin sensitivity index, and M over logarithmical insulin ratio in HEC were increased in the SITA group (all P < .01 vs baseline), which were higher than in the CONT group.

CONCLUSION

Compared with insulin intervention alone, sitagliptin plus insulin treatment appeared to maintain β-cell function and improve insulin sensitivity in LADA to some extent.

The effects of ertugliflozin on β-cell function: Pooled analysis from four phase 3 randomized controlled studies

AIM

To identify potential predictors and mediators of changes in β-cell function in response to ertugliflozin treatment in people with type 2 diabetes mellitus (T2DM).

PARTICIPANTS AND METHODS

Data from patients with T2DM randomized to ertugliflozin (5 or 15 mg; observations from both doses were pooled) or placebo in four phase 3 clinical studies (clinicaltrials.gov: NCT01958671, NCT02226003, NCT02036515, NCT02099110) were pooled and analysed. Change from baseline in β-cell function at week 26 was assessed, and its potential predictors and mediators were analysed using linear and multiple regression analyses.

RESULTS

Compared with placebo, ertugliflozin improved β-cell function when assessed by mean percent change from baseline in homeostatic model assessment of β-cell function (HOMA-%β; ertugliflozin: 14.7%, 95% confidence interval [CI] 12.3, 17.1; placebo: -0.4%, 95% CI -3.4, 2.5], but not when assessed by change in C-peptide index following a mixed meal tolerance test. Change in HOMA-%β correlated with change from baseline in glycated haemoglobin (HbA1c) and treatment with ertugliflozin, and weakly with change from baseline in body weight. In the ertugliflozin group, change in HOMA-%β correlated with baseline fasting plasma glucose (FPG; r = 0.235, P < 0.001), baseline HbA1c (r = 0.138, P < 0.001), baseline homeostatic model assessment of insulin resistance (HOMA-IR; r = 0.162, P < 0.01), and baseline HOMA-%β (r = -0.321, P < 0.001) in linear regression analyses. Multiple regression analyses yielded similar results.

DISCUSSION

In people with T2DM, ertugliflozin treatment improved fasting β-cell function, but no effect on postprandial β-cell function was observed in this analysis. Improvement in HOMA-%β was predicted by high baseline FPG, HbA1c, HOMA-IR, and low baseline HOMA-%β, and mediated by ertugliflozin treatment, and improved HbA1c and body weight.

PNPLA3 I148M is involved in the variability in anti-NAFLD response to exenatide

PURPOSE

GLP-1 receptor agonists, such as exenatide, have been proven to attenuate nonalcoholic fatty liver disease (NAFLD) in vivo and in vitro. However, the efficiency of exenatide had interindividual differences. PNPLA3 is a major susceptibility gene for NAFLD and its I148M polymorphism increases the risk of all disorders of the NAFLD spectrum. Whether this variant contributes to variability in exenatide response is still unclear.

METHODS

PNPLA3 148I knockin HepG2 cells were constructed using the Cas9/sgRNA system. Oil Red O staining combined with TG quantification was used to evaluate lipid accumulation. Western blotting and qRT-qPCR were conducted, respectively, to measure the protein and mRNA expression of lipid metabolic and endoplasmic reticulum (ER) stress-related inflammatory markers. PNPLA3 I148M was genotyped in type 2 diabetics using Sanger sequencing. The exenatide-induced changes in liver fat content and other clinical parameters were compared between PNPLA3 I148M genotypes.

RESULTS

Lipid deposition increased in both PNPLA3 148I/I and 148M/M HepG2 cells treated with palmitoleic acid, while cells with 148M/M had a higher TG content than those with 148I/I. Exendin-4 treatment was showed to be more significant in 148I/I cells than in 148M/M cells in terms of reducing the intrahepatic fat content, inhibiting SREBP-1c and ER stress-related inflammation, and activating AMPK-ACC lipid oxidation pathway. In patients with type 2 diabetes, 24-week treatment with exenatide improved liver fat content in patients carrying PNPLA3 148I/I better than in patients with 148M/M.

CONCLUSIONS

PNPLA3 I148M might modify the anti-NAFLD response to exenatide.

Efficacy of exenatide and insulin glargine on nonalcoholic fatty liver disease in patients with type 2 diabetes

BACKGROUND

The aim of this study was to investigate the efficacy of exenatide and insulin glargine in patients with newly diagnosed type 2 diabetes mellitus (T2DM) and nonalcoholic fatty liver disease (NAFLD).

METHODS

We performed a 24-week randomized controlled multicentre clinical trial. Seventy-six patients were randomly assigned 1:1 to receive exenatide or insulin glargine treatment. The endpoints included changes in liver fat content (LFC), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) measured by magnetic resonance spectroscopy, blood glucose, liver enzymes, lipid profile, body weight, and Fibrosis-4 index (FIB-4).

RESULTS

LFC, VAT, SAT, and FIB-4 were significantly reduced after exenatide treatment (ΔLFC, -17.55 ± 12.93%; ΔVAT, -43.57 ± 68.20 cm² ; ΔSAT, -28.44 ± 51.48 cm² ; ΔFIB-4, -0.10 ± 0.26; all P < .05). In comparison, only LFC (ΔLFC, -10.49 ± 11.38%; P < .05), and not VAT, SAT, or FIB-4 index (all P > .05), was reduced after insulin glargine treatment. Moreover, exenatide treatment resulted in greater reductions in alanine transaminase (ALT), aspartate transaminase (AST), and gamma glutamyl transpeptidase (GGT) than insulin glargine (P < 0.05). The body weight, waist circumference, postprandial plasma glucose, and low-density lipoprotein cholesterol (LDL-C) in the exenatide group also presented greater reductions than the insulin glargine group (P < .05). The proportion of adverse events were comparable between the two groups.

CONCLUSION

Both exenatide and insulin glargine reduced LFC in patients with drug-naive T2DM and NAFLD; however, exenatide showed greater reductions in body weight, visceral fat area, liver enzymes, FIB-4, postprandial plasma glucose, and LDL-C.

LncRNA-Malat1 is Involved in Lipotoxicity-Induced ß-cell Dysfunction and the Therapeutic Effect of Exendin-4 via Ptbp1

Increasing evidence indicates that long noncoding RNAs (lncRNAs) have crucial roles in various biological processes. However, the contribution of lncRNAs to β-cell dysfunction and their roles in diabetes therapeutics remain poorly understood. The aim of this study was to identify the lncRNAs dysregulated in diabetic islets and to explore the lncRNAs involved in β-cell function as potential therapeutic targets. By using RNA sequencing and real-time PCR, we identified thousands of lncRNAs in the islets of db/db mice and db/m littermate mice. Among the differentially expressed lncRNAs, lncRNA-Malat1 (metastasis-associated lung adenocarcinoma transcript 1) was reduced in the islets of db/db mice and palmitate-treated MIN6 cells. The results of TUNEL, Western blot and flow cytometric analyses, and GSIS assays revealed that Malat1 knockdown significantly induced β-cell apoptosis and inhibited insulin secretion. Mechanistically, RNA immunoprecipitation showed that Malat1 enhanced polypyrimidine tract-binding protein 1 (Ptbp1) protein stability by direct interaction, thereby adjusting the ratio of pyruvate kinase muscle (PKM) isoforms 1 and 2 (PKM1/PKM2). Moreover, luciferase assay and chromatin immunoprecipitation indicated that Malat1 was transcriptionally activated by pancreatic and duodenal homeobox 1 (Pdx1), through which exendin-4 alleviated lipotoxicity-induced β-cell damage. In summary, our findings suggested the involvement of Malat1 in β-cell dysfunction under diabetic conditions via the Malat1/Ptbp1/PKM2 pathway. In addition, exendin-4 ameliorated β-cell impairment by Pdx1-mediated Malat1 upregulation. Hence, Malat1 may serve as a therapeutic target for the treatment of type 2 diabetes.

Effect of Hemoglobin A1c Reduction or Weight Reduction on Blood Pressure in Glucagon-Like Peptide-1 Receptor Agonist and Sodium-Glucose Cotransporter-2 Inhibitor Treatment in Type 2 Diabetes Mellitus: A Meta-Analysis

Background Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) have shown their beneficial effects on cardiovascular outcomes and multiple cardiovascular risk factors, including hypertension. However, the mechanism of blood pressure (BP)-lowering effects of these agents has not been elucidated. This study aims to evaluate the effect of hemoglobin A1c reduction or body weight reduction with GLP-1RA treatment and SGLT2i treatment on BP changes in patients with type 2 diabetes mellitus. Methods and Results Studies were identified by a search of MEDLINE, EMBASE, and the Cochrane Central Register until June 2019. Meta-regression analysis was performed to evaluate the association between hemoglobin A1c reduction or body weight reduction and changes of BP. A total of 184 trials were included. Both GLP-1RA and SGLT2i led to significant reductions in systolic BP (weighted mean difference, -2.856 and -4.331 mm Hg, respectively; P<0.001 for both) and diastolic BP (weighted mean difference, -0.898 and -2.279 mm Hg, respectively; P<0.001 for both). For both drug classes, hemoglobin A1c reduction was not independently associated with systolic BP reduction or diastolic BP reduction. In GLP-1RA treatment, weight reduction was positively associated with systolic BP reduction and diastolic BP reduction (β=0.821 and β=0.287, respectively; P<0.001 for both). In SGLT2i treatment, weight loss was significantly associated with systolic BP reduction (β=0.820; P=0.001) but was not associated with diastolic BP reduction. Conclusions Treatment with GLP-1RA and SGLT2i led to significant reductions in BP in patients with type 2 diabetes mellitus. Weight reduction was significantly and independently associated with BP reductions in GLP-1RA treatment and SGLT2i treatment.

Predictive factors associated with glycaemic response to exenatide in Chinese patients with type 2 diabetes mellitus

WHAT IS KNOWN AND OBJECTIVE

Exenatide is widely used in the treatment of type 2 diabetes mellitus (T2DM) because of its established effect on lowering glucose and promotion of weight loss. However, therapeutic response to exenatide varies considerably among patients with T2DM. The purpose of this study was to determine which variables can predict the response to exenatide and to individualize specific therapies for patients with T2DM who need treatment with exenatide.

METHODS

This is a retrospective cohort study of patients with T2DM who were treated with exenatide twice daily as a part of their diabetes care for at least 12 months. Patients were categorized into two cohorts based on glycaemic response to exenatide use: responders and non-responders.

RESULTS AND DISCUSSION

One hundred forty-eight patients met the inclusion criteria; among them, 92 responded with an HbA1C reduction ≥1.0% from baseline HbA1C and 56 did not respond to exenatide after 6 months of exenatide treatment. Binary logistic regression analysis revealed that baseline HbA1C and duration of diabetes were identified as predictors of HbA1C reduction ≥1% at 6 months (P < .05). Linear regression analysis further identified that patients with a higher baseline HbA1C (≥7.4%) and shorter duration of diabetes (≤15.0 years) were likely to respond to exenatide, whereas those with a lower baseline HbA1C (<7.4%) and longer duration of diabetes (>15.0 years) were not likely to respond to exenatide.

WHAT IS NEW AND CONCLUSION

Our data indicate that T2DM patients with a higher baseline HbA1C and a shorter duration of diabetes are more likely to have a glycaemic response to exenatide than those with a lower baseline HbA1C and a longer duration of diabetes. The identification of predictors of therapeutic response to exenatide can provide clinically useful information for characterizing the patients who could receive the greatest benefit from exenatide.

Short-term GLP-1 receptor agonist exenatide ameliorates intramyocellular lipid deposition without weight loss in ob/ob mice

OBJECTIVE

Ectopic lipid deposition is closely associated with type 2 diabetes (T2D). Accumulating evidence shows that GLP-1 receptor agonists (GLP-1 RAs) improve obesity and liver steatosis. However, it remains unknown whether and how they ameliorate lipid deposition in skeletal muscle. This study aimed to investigate the effect of exenatide (a GLP-1 RA) on intramyocellular lipid deposition in the skeletal muscle of T2D models and its dependence on weight loss.

METHODS

Ob/ob mice and diet-induced obese (DIO) mice were treated with exenatide (24 nmol/kg), leptin (1 mg/kg), or saline control intraperitoneally once daily for 4 weeks. Phenotypic evaluations were performed during and after the intervention. PA-induced myoblast C2C12 cells were used as an in vitro model. The expression of key enzymes involved in lipid metabolism was assessed in the skeletal muscle of ob/ob mice and DIO mice.

RESULTS

In ob/ob mice, 4-week exenatide treatment did not improve the body weight and fat mass, but modestly ameliorated intramyocellular lipid deposition and lipid profiles. In DIO mice, it remarkably alleviated the body weight, lipid profiles, and intramyocellular lipid deposition. In the skeletal muscle of these two models, exenatide treatment activated the AMP-activated protein kinase (AMPK) signaling pathway, stimulated lipid oxidation enzymes, and upregulated the insulin signaling pathway. In vitro, exendin-4 activated the AMPK signaling pathway and stimulated lipid metabolism to improve lipid accumulation in palmitate-induced myoblast C2C12 cells.

CONCLUSIONS

Exenatide ameliorated intramyocellular lipid deposition without body weight reduction in ob/ob mice, but alleviated body weight and intramyocellular lipid deposition in DIO mice. The underlying mechanism included the activation of AMPK signaling pathway and improvement in insulin sensitivity, independent of weight loss in ob/ob mice.

Initial injectable therapy in type 2 diabetes: Key considerations when choosing between glucagon-like peptide 1 receptor agonists and insulin

Managing type 2 diabetes is complex and necessitates careful consideration of patient factors such as engagement in self-care, comorbidities and costs. Since type 2 diabetes is a progressive disease, many patients will require injectable agents, usually insulin. Recent ADA-EASD guidelines recommend glucagon-like peptide 1 receptor agonists (GLP-1 RAs) as first injectable therapy in most cases. The basis for this recommendation is the similar glycemic efficacy of GLP-1 RAs and insulin, but with GLP-1 RAs promoting weight loss instead of weight gain, at lower hypoglycemia risk, and with cardiovascular benefits in patients with pre-existing cardiovascular disease. GLP-1 RAs also reduce burden of glucose self-monitoring. However, tolerability and costs are important considerations, and notably, rates of drug discontinuation are often higher for GLP-1 RAs than basal insulin. To minimize risk of gastrointestinal symptoms patients should be started on lowest doses of GLP-1 RAs and up-titrated slowly. Overall healthcare costs may be lower with GLP-1 RAs compared to insulin. Though patient-level costs may still be prohibitive, GLP-1 RAs can replace 50-80 units of insulin daily and reduce costs associated with glucose self-monitoring. Decisions regarding initiating injectable therapy should be individualized. This review provides a framework to guide decision-making in the real-world setting.

Effect of baseline body mass index on glycemic control and weight change with exenatide monotherapy in Chinese drug-naïve type 2 diabetic patients

BACKGROUND

The weight-reducing effect of exenatide has been proved, but too much weight loss in normal-weight patients may concern physicians. This study evaluated the effects of exenatide monotherapy on glycemic control and weight change in normal-weight, overweight, and obese patients with newly diagnosed type 2 diabetes (T2D).

METHODS

In this multicenter prospective study, 29 normal-weight, 54 overweight, and 27 obese newly diagnosed and drug-naïve patients with T2D were treated with exenatide for 48 weeks. The primary efficacy endpoint was the effect of baseline body mass index (BMI) on glycemic control, measured as the change in HbA1c from baseline to Week 48 compared among different BMI groups. Other endpoints included comparisons of the effects of exenatide on fasting plasma glucose (FPG), postprandial plasma glucose (PPG), body weight, and other metabolic indices.

RESULTS

After 48-week treatment, the estimated mean changes in HbA1c in normal-weight, overweight, and obese patients were -1.9%, -1.8%, and -1.5%, respectively (P = 0.290 among groups after adjustment for baseline values). There were similar declines in FPG and 0.5- and 2-hour PPG among groups. There were non-significant trends from normal-weight to overweight to obese patients for increased weight reduction (decreases of 2.2, 3.9, and 4.0 kg, respectively; P = 0.104) and changes in waist circumference (decreases of 2.2, 3.2, and 5.6 cm, respectively; P = 0.078).

CONCLUSIONS

Baseline BMI had no effect on glycemic control, weight change, or other metabolic indices with exenatide monotherapy. Normal-weight patients with T2D would benefit from exenatide as much as overweight or obese patients on glucose control, without increased risk of excess weight loss.

Risk of Malignant Neoplasia with Glucagon-Like Peptide-1 Receptor Agonist Treatment in Patients with Type 2 Diabetes: A Meta-Analysis

BACKGROUND

Glucagon-like peptide-1 (GLP-1) receptor agonists are effective glucose-lowering drugs, but there is concern that they may increase the risk of malignant neoplasia. The present meta-analysis examined the safety of GLP-1 receptor agonists with regard to malignant neoplasia.

METHODS

We analyzed data from randomized controlled trials with a minimum duration of 24 weeks that assessed the incidence of neoplasms in type 2 diabetes patients receiving GLP-1 receptor agonists compared with placebo or other hypoglycemic drugs. We searched the MEDLINE, Embase, and Cochrane databases with a language restriction of English through October 1, 2018, and carried out a meta-analysis of the available trial data using a fixed effects model to calculate odds ratios (ORs) for neoplasia.

RESULTS

Thirty-four relevant articles, providing data for 50452 patients, were included in the meta-analysis. Compared with the incidence of malignant neoplasia with placebo or other interventions, no increase in malignant neoplasm formation was observed with the use of GLP-1 receptor agonists (OR 1.04, 95% confidence interval (CI) 0.94-1.15; p = 0.46), liraglutide (OR 1.08, 95% CI 0.91-1.27; p = 0.38), exenatide (OR 1.00, 95% CI 0.86-1.16; p = 1.00), semaglutide (OR 0.89, 95% CI 0.35-2.22; p = 0.80), or albiglutide (OR 1.07, 95% CI 0.23-4.88; p = 0.93). A subanalysis of trials lasting longer than 3 years also showed no increase in the neoplasia risk with GLP-1 receptor agonist use (OR 1.03, 95% CI 0.92-1.15; p = 0.60). Between-trial statistical heterogeneity was low for all comparisons.

CONCLUSION

GLP-1 receptor agonists can be used without safety concerns related to malignant neoplasia in patients with type 2 diabetes.

The Effects of Exenatide Once Weekly (EXQW) and Exenatide Twice a Day (EXBID) on Beta-Cell Function in Type 2 Diabetes: A Systematic Review and Network Meta-Analysis

BACKGROUND

In patients with type 2 diabetes mellitus (T2DM) and poor glycemic control receiving metformin (MET), glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are recommended as the adjunctive therapy. However, there are only a few studies involving the comparative effects of exenatide twice a day (EXBID) and exenatide once weekly (EXQW) on HOMA-β. This meta assessed the comparative effects of EXQW and EXBID on HOMA-β among T2DM patients.

MATERIALS AND METHODS

PubMed, Cochrane Library, and Embase databases were searched to collect randomized controlled trials (RCTs). Network meta-analysis was performed, and network diagrams were constructed to evaluate the effects. The primary outcome is HOMA-β, and the secondary outcomes are fasting blood glycose (FBG), glycated hemoglobin (HbA1c), and weight loss.

RESULTS

A total of 8 studies with 3506 subjects were included. Compared with other antidiabetic agents, EXQW has a greater improvement in HOMA-β than EXBID (weight mean difference (WMD) = -0.46, 95% confidence interval (CI) [-0.64, -0.28], P = 0.001). The effect of EXQW on HbA1c is superior to that of sitagliptin (SITA) (WMD = 0.51, 95% CI [0.03, 0.99], P = 0.037). The significant reduction of weight was detected for EXBID in comparison with EXQW (WMD = -0.73, 95% CI [-1.13, -0.33], P = 0.001), and no significant difference was found between EXQW and MET.

CONCLUSIONS

EXQW shows a greater improvement in HOMA-β than EXBID. Moreover, the efficacy of EXQW on glycemic control is similar to other antidiabetic agents including EXBID. It is an advisable treatment for diabetic patients to improve HOMA-β and has an advantage of fewer number of injections compared with EXBID, to increase patients' adherence and quality of life.

Glucagon-like peptide-1 mimetics, optimal for Asian type 2 diabetes patients with and without overweight/obesity: meta-analysis of randomized controlled trials

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are desirable for diabetes, especially in patients with overweight/obesity. We aimed to determine whether GLP-1RAs exhibit different glucose-lowering efficacies between Asian type 2 diabetes (T2D) patients with and without overweight/obesity. Randomized controlled trials were searched in EMBASE, MEDLINE, CENTRAL, and ClinicalTrials.gov. Studies published in English with treatment duration ≥12 weeks and information on HbA1c changes were included. The studies were divided into normal body mass index (BMI) and overweight/obese groups according to baseline BMI. Among 3190 searched studies, 20 trials were included in the meta-analysis. The standardized mean differences in HbA1c change, fasting glucose change, and postprandial glucose change were equivalent between normal BMI and overweight/obese studies (p > 0.05). The relative risk of HbA1c < 6.5% target achievement in normal BMI trials (7.93; 95% confidence interval: 3.27, 19.20) was superior to that in overweight/obesity trials (2.23; 1.67, 2.97), with a significant difference (p = 0.020). Body weight loss (p = 0.572) and hypoglycemic risk(p = 0.920) were similar in the two groups. The glucose-lowering effects of GLP-1RAs were equivalent among Asian T2D patients. With their advantages for weight-loss or weight-maintenance, GLP-1RAs are optimal medicines for Asian T2D patients with and without overweight/obesity.

Pioglitazone and the secondary prevention of cardiovascular disease. A meta-analysis of randomized-controlled trials

Background and aims

Pioglitazone targets multiple pathogenic pathways involved in the development of cardiovascular diseases (CVD). The aim of this systematic review and meta-analysis is to assess the effects of pioglitazone treatment on the secondary prevention of CVD.

Methods

Randomized-controlled trials of pioglitazone in patients with CVD were identified through PubMed, Embase, Cochrane and CINAHL, in a search up to May 2016. Studies were included if pioglitazone was compared with any control (usual care, placebo or active comparator) and if patients were previously diagnosed with CVD. The outcomes of interest included major adverse cardiovascular events (MACE), myocardial infarction (MI), stroke, all-cause mortality and heart failure (HF). All outcomes were compared by pooled risk ratios (RR) with a 95% confidence interval (CI). Pooled estimates were calculated using a random-effects model.

Results

Ten studies reported the effects of pioglitazone on any of the outcomes of interest. Pioglitazone reduced recurrent MACE (RR 0.74, 95% 0.60–0.92; I² = 35), MI (RR 0.77, 95% CI 0.64–0.93; I² = 0%), or stroke (RR 0.81, 95% CI 0.68–0.96; I² = 0%). Pioglitazone did not reduce all-cause mortality (RR 0.94, 95% CI 0.81–1.08; I² = 0%), whereas pioglitazone treatment was associated with an increased risk of HF (RR 1.33, 95% CI 1.14–1.54).

Conclusions

Pioglitazone lowers the risk of recurrent MACE, stroke, or MI in patients with clinical manifest vascular disease. Pioglitazone does not lower the risk for all-cause mortality, and increases the risk for the development of HF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0617-4) contains supplementary material, which is available to authorized users.

Treatment Strategy for Type 2 Diabetes with Obesity: Focus on Glucagon-like Peptide-1 Receptor Agonists

PURPOSE

The progressive nature of type 2 diabetes mellitus (T2DM) calls for step-wise intensification of therapy for maintaining normal glycemic levels and lowering cardiovascular (CV) risk. Because obesity is a prominent risk factor and comorbidity of T2DM, it further elevates the CV risk in T2DM. Therefore, it is vital to manage weight, obesity, and glycemic parameters for effective T2DM management. Few oral antidiabetic drugs (sulfonylureas and thiazolidinediones) and insulin are not suitable for obese patients with T2DM because these drugs cause weight gain. The present review discusses the place of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in the treatment of obese patients with T2DM and the significance of these drugs in the prevention of future CV risk in patients with T2DM.

METHODS

A literature search of PubMed and EMBASE was conducted by using the search terms T2DM, GLP-1RAs, obesity, and cardiovascular complication. Randomized controlled trials measuring the effect of GLP-1RAs versus that of placebo on CV outcomes were included in the review.

FINDINGS

GLP-1RAs have emerged as a therapeutic alternative; these drugs exert their actions by providing glycemic control, improving insulin resistance and ö̇-cell function, and reducing weight. The risk of hypoglycemia with GLP-1RAs is minimal; however, GLP-1RAs are associated with gastrointestinal adverse events and raise concerns regarding pancreatitis. Combining GLP-1RAs with insulin analogues results in higher efficacy, a lowered insulin dose, and reduced insulin-related hypoglycemia and weight gain. Longer acting GLP-1RAs are also associated with improvement in medication adherence. Improvement in CV risk factors such as blood pressure and lipid profile further increases their usability for improving CV outcomes.

IMPLICATIONS

Overall, the properties of GLP-1RAs make them suitable for combination with oral antidiabetic drugs in the early stages of T2DM and with insulins in the later stages for optimizing comprehensive management of the disease.

Glucagon-like peptide-1 receptor agonists: a systematic review of comparative effectiveness research

BACKGROUND

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) act by increasing insulin secretion, decreasing glucagon secretion, slowing gastric emptying, and increasing satiety.

OBJECTIVE

Published evidence directly comparing GLP-1RAs with other approved treatments for type 2 diabetes (T2D) was systematically reviewed.

METHODS

A literature search was performed using MEDLINE and Embase databases to identify papers comparing GLP-1RAs with other classes of glucose-lowering therapy in patients with T2D.

RESULTS

Of the 1303 papers identified, 57 met the prespecified criteria for a high-quality clinical trial or retrospective study. The efficacy and tolerability of approved GLP-1RAs (exenatide twice daily or once weekly, dulaglutide, liraglutide, lixisenatide, and albiglutide) were compared with insulin products (23 prospective studies + seven retrospective studies), dipeptidyl peptidase-4 inhibitors (11 prospective studies + three retrospective studies), sulfonylureas (nine prospective studies + one retrospective study), thiazolidinediones (five prospective studies), and metformin (two prospective studies). GLP-1RAs are effective as a second-line therapy in improving glycemic parameters in patients with T2D. Reductions in glycated hemoglobin from baseline with GLP-1RAs tended to be greater or similar compared with insulin therapy. GLP-1RAs were consistently more effective in reducing body weight than most oral glucose-lowering drugs and insulin and were associated with lower hypoglycemia risk versus insulin or sulfonylureas. GLP-1RAs improved cardiovascular risk factors, and preliminary data suggest they improve cardiovascular outcomes in patients with T2D compared with oral glucose-lowering drugs. However, results from ongoing studies are awaited to confirm these early findings.

CONCLUSION

This systematic review found that GLP-1RAs are an effective class of glucose-lowering drugs for T2D.

Effects of pioglitazone therapy on blood parameters, weight and BMI: a meta-analysis

BACKGROUND

Type 2 diabetes mellitus (T2DM) is one of the most common diseases worldwide and insulin insufficiency and insulin resistance are two main metabolic issues connected with it. The dyslipidemia associated with insulin resistance and T2DM is characterized by higher triglycerides (TGs), higher very-low-density lipoprotein cholesterol and lower apo A1. Pioglitazone, a member of the thiazolidinedione class, with a proven antihyperglycemic effect, is known to positively influence insulin sensitivity and β-cell function and to have the potential to alter the lipid profile.

METHODS

The aim of our meta-analysis is to summarize and determine the influence of pioglitazone on the glycemic profile and lipoprotein metabolism as well as on weight and BMI in order to highlight the benefit of pioglitazone therapy in patients with T2DM. A comprehensive literature search was conducted through the electronic databases PubMed, MEDLINE, Scopus, PsyInfo, eLIBRARY.ru (from 2000 until February 2016) to identify studies that investigate the effect of pioglitazone on the glycemic and lipid profile and on the weight and BMI. We chose the random-effects method as the primary analysis. Forest plots depict estimated results from the studies included in the analysis and funnel plots are used to evaluate publication bias. Sensitivity analyses were performed in order to evaluate the degree of influence of the consequent elimination of each individual study on the final result.

RESULTS

Of the 1536 identified sources only 15 randomised trials were included in the meta-analysis. Pioglitazone treatment was associated with improvement in the glycemic profile. It reduced FPG levels by a mean of 1.1-2 mmol/l and HbA1c by a mean of 0.9-1.3%. Our results reaffirmed the hypothesis that pioglitazone has a positive influence on the lipid profile of T2DM patients with increase in TC and HDL, no significant changes in LDL and notable decrease in TGs. Results also showed that pioglitazone therapy led to increase in both weight and BMI (WMD 1.755, 95% CI 0.674 to 2.837 and 1.145, 95% CI 0.389 to 1.901 respectively).

CONCLUSION

Our results prove that the PPAR γ agonist pioglitazone has the potential to be beneficial to patients with T2DM.

Exenatide treatment increases serum irisin levels in patients with obesity and newly diagnosed type 2 diabetes

OBJECTIVE

Irisin is a myokine secreted by skeletal muscle during exercise. Abnormal serum irisin levels are associated with obesity and type 2 diabetes (T2D). This study investigated the changes in serum irisin in the obese patients with newly diagnosed T2D following glucagon-like peptide-1 (GLP-1) receptor agonist (exenatide) treatment.

METHODS

Fifty-four obese patients with T2D were treated with exenatide for 12weeks. The control group included 54 age-, sex-, and body mass index (BMI)-matched subjects with normal glucose tolerance.

RESULTS

Patients with T2D had lower irisin than the control group (38.06 [29.29-53.79] vs. 58.01 [43.07-87.79] ng/mL, P<0.01]. Serum irisin was negatively associated with BMI (r=-0.178, P<0.05), fasting blood glucose (FBG; r=-0.170, P<0.05), and glycosylated hemoglobin (HbA1c; r=-0.189, P<0.01) in patients with T2D. Exenatide treatment markedly increased serum irisin by 19.28ng/mL (12.59-25.98) compared to baseline (P<0.01). Increased irisin was significantly correlated with decreased FBG and HbA1c after exenatide treatment (FBG: r=-0.35; HbA1c: r=-0.37; both P<0.05).

CONCLUSIONS

Exenatide treatment significantly increased irisin in patients with T2D. Post-treatment changes in irisin were correlated with decreases in FBG and HbA1c. The upregulation of irisin might be a novel mechanism for the beneficial effects of exenatide in type 2 diabetic patients.

Treatment potential of the GLP-1 receptor agonists in type 2 diabetes mellitus: a review

Over the last decade, the discovery of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) has increased the treatment options for patients with type 2 diabetes mellitus (T2DM). GLP-1 RAs mimic the effects of native GLP-1, which increases insulin secretion, inhibits glucagon secretion, increases satiety and slows gastric emptying. This review evaluates the phase III trials for all approved GLP-1 RAs and reports that all GLP-1 RAs decrease HbA1c, fasting plasma glucose, and lead to a reduction in body weight in the majority of trials. The most common adverse events are nausea and other gastrointestinal discomfort, while hypoglycaemia is rarely reported when GLP-1 RAs not are combined with sulfonylurea or insulin. Treatment options in the near future will include co-formulations of basal insulin and a GLP-1 RA.

Pioglitazone Inhibits the Development of Hyperalgesia and Sensitization of Spinal Nociresponsive Neurons in Type 2 Diabetes

Thiazolidinedione drugs (TZDs) such as pioglitazone are approved by the U.S. Food and Drug Administration for the treatment of insulin resistance in type 2 diabetes. However, whether TZDs reduce painful diabetic neuropathy (PDN) remains unknown. Therefore, we tested the hypothesis that chronic administration of pioglitazone would reduce PDN in Zucker Diabetic Fatty (ZDF(fa/fa) [ZDF]) rats. Compared with Zucker Lean (ZL(fa/+)) controls, ZDF rats developed: (1) increased blood glucose, hemoglobin A1c, methylglyoxal, and insulin levels; (2) mechanical and thermal hyperalgesia in the hind paw; (3) increased avoidance of noxious mechanical probes in a mechanical conflict avoidance behavioral assay, to our knowledge, the first report of a measure of affective-motivational pain-like behavior in ZDF rats; and (4) exaggerated lumbar dorsal horn immunohistochemical expression of pressure-evoked phosphorylated extracellular signal-regulated kinase. Seven weeks of pioglitazone (30 mg/kg/d in food) reduced blood glucose, hemoglobin A1c, hyperalgesia, and phosphorylated extracellular signal-regulated kinase expression in ZDF. To our knowledge, this is the first report to reveal hyperalgesia and spinal sensitization in the same ZDF animals, both evoked by a noxious mechanical stimulus that reflects pressure pain frequently associated with clinical PDN. Because pioglitazone provides the combined benefit of reducing hyperglycemia, hyperalgesia, and central sensitization, we suggest that TZDs represent an attractive pharmacotherapy in patients with type 2 diabetes-associated pain.

PERSPECTIVE

To our knowledge, this is the first preclinical report to show that: (1) ZDF rats exhibit hyperalgesia and affective-motivational pain concurrent with central sensitization; and (2) pioglitazone reduces hyperalgesia and spinal sensitization to noxious mechanical stimulation within the same subjects. Further studies are needed to determine the anti-PDN effect of TZDs in humans.

Effect of exenatide, insulin and pioglitazone on bone metabolism in patients with newly diagnosed type 2 diabetes

AIM

Preclinical studies suggested that insulin, incretin and thiazolidinediones had effect on regulation of bone metabolism. But clinical evidence is limited. We assessed the effects of these antihyperglycemic agents on bone metabolism in patients with newly diagnosed type 2 diabetes.

METHODS

The present study was a two-center, randomized, parallel-group clinical trial. Sixty-two newly diagnosed and drug-naïve patients with type 2 diabetes were randomized to exenatide (EXE, n = 20), mixed protamine zinc recombinant human insulin lispro injection (25R; INS, n = 21) or pioglitazone (PIO, n = 21) group for a 24-week treatment. Glycosylated hemoglobin A1c (HbA1c), body weight, body mineral density (BMD) and fasting serum concentration of bone turnover markers including osteocalcin (OC), C-telopeptide of type I collagen (CTX) and tartrate-resistant alkaline phosphatase 5b (TRAcP5b) were assessed at baseline and week 24.

RESULTS

Baseline characteristics were similar among groups. At week 24, HbA1c improved in all patients (EXE:-2.4 ± 0.3 %, INS:-2.4 ± 0.3 %, PIO:-2.0 ± 0.2 %; p > 0.05 among groups). Patients treated with exenatide lost body weight remarkably (-4.7 ± 0.8 kg). In spite of the amelioration of glucose control, no significant improvement of OC, CTX or TRAcP5b was observed at week 24 (EXE: OC -0.619 ± 0.728 ng/ml, CTX 0.147 ± 0.046 ng/ml, TRAcP5b 0.302 ± 0.149 U/L;INS: OC 0.637 ± 0.787 ng/ml, CTX -0.012 ± 0.074 ng/ml, TRAcP5b 0.124 ± 0.395 U/L; PIO: OC -0.150 ± 0.691 ng/ml, CTX 0.073 ± 0.094 ng/ml, TRAcP5b 0.586 ± 0.183 U/L; p > 0.05), as well as BMD measurement, regardless of the treatments.

CONCLUSIONS

Twenty-four-week treatment with exenatide, insulin and pioglitazone improved glucose control in patients with newly diagnosed type 2 diabetes, but had no impact on bone turnover markers or BMD.

GLP-1 Receptor Agonist Exenatide Attenuates the Detrimental Effects of Obesity on Inflammatory Profile in Testis and Sperm Quality in Mice

PROBLEM

Male obesity has been linked to subfecundity. This study is to investigate the effects of GLP-1 receptor (GLP-1R) agonist exenatide on sperm quality in high-fat diet (HFD)-induced obese mice.

METHOD OF STUDY

After 12 weeks of chow diet (CD) or HFD challenge, mice on HFD were allocated to either saline or exenatide (24 nmol/kg/day) interventions for 8 weeks. Sperm quality and the inflammatory profile of testis were compared among three groups.

RESULTS

Obesity reduced the quality of sperm and changed the inflammatory profile characterized by increased mRNA expression levels of TNF-α, MCP-1, and F4/80 in testis. Exenatide intervention reduced the expression of pro-inflammatory cytokines and improved the quality of sperm.

CONCLUSION

HFD-induced obesity leads to the impairment of sperm quality and increased inflammation of testis in mice, and the abnormal physiology can be attenuated by exenatide treatment. Exenatide treatment may bring additional profits to obese and diabetes men by improving sperm function.

Exenatide once-weekly injection for the treatment of type 2 diabetes in Chinese patients: current perspectives

Glucagon-like peptide-1 (GLP-1) analogs, such as exenatide, have played an important role as antidiabetic medications in the treatment of type 2 diabetes (T2DM). Like most other hypoglycemic agents, exenatide has a number of actions, including lowering blood glucose, promoting weight loss, improving insulin resistance, and protecting islet β-cells. Although GLP-1 analogs, combined with other antidiabetic medications, have excellent performance in T2DM, some side effects and imperfections limit its use in clinical practice. Since 2012, a new generation GLP-1 agent, exenatide once weekly (QW), has been available for patients with T2DM in the USA, but not as yet in the People’s Republic of China. Previous data indicate that exenatide QW achieves better fasting glucose reductions than sitagliptin or exenatide twice daily, whilst appearing non-inferior to pioglitazone and achieving less reductions than insulin glargine. Exenatide QW was better at improving average postprandial glucose than sitagliptin or titrated insulin glargine, but was inferior to exenatide twice daily. Additionally exenatide QW has a better effect in terms of weight loss than other glycemic medications. Exenatide QW can also reduce blood lipids and lower blood pressure. Accordingly, exenatide QW is cost-effective, achieves good clinical outcomes, and has acceptable side effects, indicating that it has promising prospects for future use in the People’s Republic of China.

Racial/ethnic disparities in prevalence and care of patients with type 2 diabetes mellitus

BACKGROUND

As of 2012, nearly 10% of Americans had diabetes mellitus. People with diabetes are at approximately double the risk of premature death compared with those in the same age groups without the condition. While the prevalence of diabetes has risen across all racial/ethnic groups over the past 30 years, rates are higher in minority populations. The objective of this review article is to evaluate the prevalence of diabetes and disease-related comorbidities as well as the primary endpoints of clinical studies assessing glucose-lowering treatments in African Americans, Hispanics, and Asians.

METHODS

As part of our examination of this topic, we reviewed epidemiologic and outcome publications. Additionally, we performed a comprehensive literature search of clinical trials that evaluated glucose-lowering drugs in racial minority populations. For race/ethnicity, we used the terms African American, African, Hispanic, and Asian. We searched PubMed for clinical trial results from 1996 to 2015 using these terms by drug class and specific drug. Search results were filtered qualitatively.

RESULTS

Overall, the majority of publications that fit our search criteria pertained to native Asian patient populations (i.e., Asian patients in Asian countries). Sulfonylureas; the α-glucosidase inhibitor, miglitol; the biguanide, metformin; and the thiazolidinedione, rosiglitazone have been evaluated in African American and Hispanic populations, as well as in Asians. The literature on other glucose-lowering drugs in non-white races/ethnicities is more limited.

CONCLUSIONS

Clinical data are needed for guiding diabetes treatment among racial minority populations. A multi-faceted approach, including vigilant screening in at-risk populations, aggressive treatment, and culturally sensitive patient education, could help reduce the burden of diabetes on minority populations. To ensure optimal outcomes, educational programs that integrate culturally relevant approaches should highlight the importance of risk-factor control in minority patients.

Adverse Effects of GLP-1 Receptor Agonists

Glucagon-like peptide-1 (GLP-1) receptor agonists are a class of injective anti-diabetic drugs that improve glycemic control and many other atherosclerosis-related parameters in patients with type 2 diabetes (T2D). However, the use of this relatively new class of drugs may be associated with certain adverse effects. Concerns have been expressed regarding the effects of these drugs on pancreatic and thyroid tissue, since animal studies and analyses of drug databases indicate an association of GLP-1 receptor agonists with pancreatitis, pancreatic cancer, and thyroid cancer. However, several meta-analyses failed to confirm a cause-effect relation between GLP-1 receptor agonists and the development of these adverse effects. One benefit of GLP-1 receptor agonists is that they do not cause hypoglycemia when combined with metformin or thiazolidinediones, but the dose of concomitant sulphonylurea or insulin may have to be decreased to reduce the risk of hypoglycemic episodes. On the other hand, several case reports have linked the use of these drugs, mainly exenatide, with the occurrence of acute kidney injury, primarily through hemodynamic derangement due to nausea, vomiting, and diarrhea. The most common symptoms associated with the use of GLP-1 receptor agonists are gastrointestinal symptoms, mainly nausea. Other common adverse effects include injection site reactions, headache, and nasopharyngitis, but these effects do not usually result in discontinuation of the drug. Current evidence shows that GLP-1 receptor agonists have no negative effects on the cardiovascular risk of patients with T2D. Thus, GLP-1 receptor agonists appear to have a favorable safety profile, but ongoing trials will further assess their cardiovascular effects. The aim of this review is to analyze critically the available data regarding adverse events of GLP-1 receptor agonists in different anatomic systems published in Pubmed and Scopus. Whenever possible, certain differences between GLP-1 receptor agonists are described. The review also provides the reader with structured data that compare the rates of the most common adverse effects for each of the various GLP-1 receptor agonists.

Exenatide can inhibit calcification of human VSMCs through the NF-kappaB/RANKL signaling pathway

Background

Arterial calcification is an important pathological change of diabetic vascular complication. Osteoblastic differentiation of vascular smooth muscle cells (VSMCs) plays an important cytopathologic role in arterial calcification. The glucagon-like peptide-1 receptor agonists (GLP-1RA), a novel type of antidiabetic drugs, exert cardioprotective effects through the GLP-1 receptor (GLP-1R). However, the question of whether or not GLP-1RA regulates osteoblastic differentiation and calcification of VSMCs has not been answered, and the associated molecular mechanisms have not been examined.

Methods

Calcifying VSMCs (CVSMCs) were isolated from cultured human arterial smooth muscle cells through limiting dilution and cloning. The extent of matrix mineralization was measured by Alizarin Red S staining. Protein expression and phosphorylation were detected by Western blot. Gene expression of receptor activator of nuclear factor-κB ligand (RANKL) was silenced by small interference RNA (siRNA).

Results

Exenatide, an agonist of GLP-1 receptor, attenuated β-glycerol phosphate (β-GP) induced osteoblastic differentiation and calcification of human CVSMCs in a dose- and time-dependent manner. RANKL siRNA also inhibited osteoblastic differentiation and calcification. Exenatide decreased the expression of RANKL in a dose-dependent manner. 1,25 vitD₃ (an activator of RANKL) upregulated, whereas BAY11-7082 (an inhibitor of NF-κB) downregulated RANKL, alkaline phosphatase (ALP), osteocalcin (OC), and core binding factor α1 (Runx2) protein levels and reduced mineralization in human CVSMCs. Exenatide decreased p-NF-κB and increased p-AMPKα levels in human CVSMCs 48 h after treatment. Significant decrease in p-NF-κB (p-Ser²⁷⁶, p-Ser⁵³⁶) level was observed in cells treated with exenatide or exenatide + BAY11-7082.

Conclusion

GLP-1RA exenatide can inhibit human VSMCs calcification through NF-κB/RANKL signaling.

Effects of exenatide, insulin, and pioglitazone on liver fat content and body fat distributions in drug-naive subjects with type 2 diabetes

Ectopic accumulation of lipids in nonadipose tissues plays a primary role in the pathogenesis of type 2 diabetes mellitus (T2DM). This study was to examine the effects of exenatide, insulin, and pioglitazone on liver fat content and body fat distributions in T2DM. Thirty-three drug-naive T2DM patients (age 52.7 ± 1.7 years, HbA1c 8.7 ± 0.2 %, body mass index 24.5 ± 0.5 kg/m(2)) were randomized into exenatide, insulin, or pioglitazone for 6 months. Intrahepatic fat (IHF), visceral fat (VF), and subcutaneous fat (SF) were measured using proton nuclear magnetic resonance spectroscopy. Plasma tumor necrosis factor α (TNFα) and adiponectin were assayed by ELISA. HbA1c declined significantly in all three groups. Body weight, waist, and serum triglycerides decreased with exenatide. After interventions, IHF significantly reduced with three treatments (exenatide Δ = -68 %, insulin Δ = -58 %, pioglitazone Δ = -49 %). Exenatide reduced VF (Δ = -36 %) and SF (Δ = -13 %), and pioglitazone decreased VF (Δ = -30 %) with no impact on SF, whereas insulin had no impact on VF or SF. Levels of TNFα (exenatide/insulin/pioglitazone) decreased, and levels of adiponectin (exenatide/pioglitazone) increased. Analysis showed that ΔIHF correlated with ΔHbA1c and Δweight. Besides, ΔIHF correlated with Δtriglycerides and ΔTNFα, but the correlations fell short of significance after BMI adjustment. By linear regression analysis, ΔHbA1c alone explained 41.5 % of the variance of ΔIHF, and ΔHbA1c + Δweight explained 57.6 % of the variance. Liver fat content can be significantly reduced irrespective of using exenatide, insulin, and pioglitazone. Early glycaemic control plays an important role in slowing progression of fatty liver in T2DM.