Systematic Literature Review of DPP-4 Inhibitors in Patients with Type 2 Diabetes Mellitus and Renal Impairment

Real-World Glycemic Lowering Effectiveness of Linagliptin Among Adults with Type 2 Diabetes by Age, Renal Function, and Race

INTRODUCTION

To assess real-world effectiveness of linagliptin in persons with type 2 diabetes mellitus (T2DM) across a range of ages and renal function. Effectiveness was assessed in different races, with a focus on African Americans (AA).

METHODS

This was a non-interventional retrospective cohort study using data in the Optum clinical database from adults with T2DM initiating linagliptin. Date of the first linagliptin prescription was the index date. Outcomes included change in glycated hemoglobin (HbA1c) and the percentage of persons achieving an HbA1c < 7% (53 mmol/mol) during the 60-180 days following linagliptin initiation. Analyses of age by renal function were conducted. Multivariate regression analysis was performed to assess change in HbA1c, controlling for an a priori list of covariates.

RESULTS

Overall, 11,001 persons were included. Mean pre-index HbA1c value was 8.2% (66 mmol/mol), with higher levels in younger versus older persons and AAs versus other race groups. Persons initiating linagliptin had an average HbA1c reduction of 0.51% (5.6 mmol/mol). Without adjusting for age, renal function, race, and pre-index HbA1c, greater reductions in HbA1c were observed in younger versus older persons, persons with higher versus lower estimated glomerular filtration rate (eGFR), and AAs versus white or Asians. After multivariate analysis, variables significantly associated with a greater HbA1c reduction included higher pre-index HbA1c and older age.

CONCLUSIONS

These results support the HbA1c-lowering effectiveness of linagliptin across age, race, and renal function categories among a large real-world population of adults with T2DM.

Long-Term, Real-World Safety and Efficacy of Teneligliptin: A Post-Marketing Surveillance of More Than 10,000 Patients with Type 2 Diabetes in Japan

INTRODUCTION

Teneligliptin is a dipeptidyl peptidase 4 inhibitor that was approved for the treatment of type 2 diabetes mellitus (T2DM) in Japan in 2012. We performed a long-term post-marketing surveillance (RUBY) to obtain real-world evidence regarding the safety and efficacy of teneligliptin in Japan.

METHODS

This 3-year follow-up RUBY surveillance registered patients with T2DM who started treatment with teneligliptin between May 2013 and February 2015 in Japan. Collected data included demographics, treatments, adverse drug reactions (ADRs) and laboratory variables. Data were evaluated in all patients and in patients divided according to baseline renal function across categories of estimated glomerular filtration rate (G1-G5) and dialysis. Safety was assessed as the incidence of ADRs and efficacy was assessed in terms of glycaemic control, for up to 3 years.

RESULTS

Of 11,677 patients registered, 10,696 and 10,249 were evaluable for safety and efficacy analyses, respectively. The median duration of exposure was 1096 days. ADRs occurred in 412 patients (3.85%) and were serious in 117 patients (1.09%). The most frequent ADR class was gastrointestinal disorders (0.68%), which included constipation. There were no new ADRs warranting attention beyond those already described in teneligliptin's package insert. ADRs and serious ADRs in renal function subgroups occurred in 3.24-7.14% and 0.65-5.36% in G1-G5, and 4.49% and 1.92% in patients on dialysis, respectively. Reduction in HbA1c was sustained for 3 years after starting teneligliptin (- 0.70% ± 1.36%, p < 0.001 at 3 years). The least-squares mean changes in HbA1c adjusted for baseline were - 0.76% to - 0.66% in G1-G5 at 3 years. Glycated albumin levels decreased in patients on dialysis (- 2.92% ± 4.78% at 3 years).

CONCLUSION

There were no new safety or efficacy concerns about teneligliptin used in long-term, real-world, clinical settings in patients with T2DM with any stages of renal impairment.

TRIAL REGISTRATION

Japan Pharmaceutical Information Center clinical trials database identifier: Japic CTI-153047. Plain language summary available for this article.

Comparing treatment intensification and clinical outcomes of metformin and dipeptidyl peptidase-4 inhibitors in treatment-naïve patients with type 2 diabetes in Japan

Japan's guidelines emphasize tailored therapy, but do not guide physicians on the use of a specific regimen in drug-naive patients. The role of long-term initial therapy could be important in key elements of diabetes treatment, such as continuation of the initially prescribed drug. We investigated the frequency of occurrence to treatment intensification after the initiation of metformin or dipeptidyl peptidase-4 inhibitor treatment. In multivariable-adjusted Cox proportional hazards models, initiation of dipeptidyl peptidase-4 inhibitor was associated with a low hazard of intensification. The findings of this survey showed that dipeptidyl peptidase-4 inhibitors were the preferred first-line treatment in Japan because of the high continuation rate of the treatment and hemoglobin A1c-lowering effect. This information would provide guidance in selecting initial hypoglycemic drugs to optimize the treatment of type 2 diabetes mellitus patients in Japan and Asia.

Ten years of experience with DPP-4 inhibitors for the treatment of type 2 diabetes mellitus

Achieving and maintaining recommended glycemic targets without causing adverse e ffects, including hypoglycemia, is challenging, especially in older patients with type 2 diabetes mellitus (T2DM). The introduction of dipeptidyl peptidase-4 (DPP-4) inhibitors, more than 10 years ago, has provided an alternative to conventional medications for the intensification of glucose-lowering treatment after failure of metformin monotherapy, and therefore, marked an important advance in the management of T2DM. By prolonging the activity of incretin hormones, DPP-4 inhibitors induce insulin release and decrease glucagon secretion in a glucose-dependent manner. This results in a more physiologic glycemic control as compared to that ensured by insulin secretagogues (sulfonylureas and glinides). Overall, DPP-4 inhibitors have a favorable safety profile and can be used without dose adjustments in older adults and in patients with mild renal impairment; they have a neutral effect on body weight and do not cause hypoglycemia by themselves. Safety issues, reported mainly in post-marketing surveillance programs and including cardiovascular outcomes and the risk of acute pancreatitis, are being extensively investigated. The aim of this review is to discuss the impact of DPP-4 inhibitors on the treatment of T2DM, after 10 years of experience, with an emphasis on diabetes care in Italy. We will first describe T2DM treatment in Italy and then provide an overview of the main findings from randomized controlled trials, real-world studies and post-marketing surveillance programs with DPP-4 inhibitors.

Therapeutic Experience of Saxagliptin as First Add-on after Metformin in Indian Type 2 Diabetes Patients: A Non-interventional, Prospective, Observational Study (ONTARGET-INDIA)

INTRODUCTION

Dipeptidyl peptidase 4 (DPP4) inhibitors are widely used in type 2 diabetes mellitus (T2DM) patients but the data available in existing clinical trial programmes on DPP4 inhibitors include limited number of patients from India. Hence, this study attempted to understand usage, efficacy and safety of saxagliptin as first add-on after metformin in Indians with T2DM.

METHODOLOGY

It was a multicenter, prospective, non-interventional and observational study planned to enrol T2DM patients who were inadequately controlled with metformin alone and had been recently (i.e., within past 15 days) prescribed saxagliptin as an add-on to metformin. Type 1 diabetes mellitus, use of glucose lowering drugs apart from metformin or saxagliptin, pregnancy, lactation, and medical condition, which could interfere with safe completion of the study were excluded.

RESULTS

A total of 1109 participants (658 men and 451 women) with mean ± SD age of 51.17 ± 11.85 years were enrolled from 50 centres throughout India. Significant reduction was observed in mean ± SD change of HbA1c as - 0.86% ± 1.76 from baseline to after 3 months of therapy (P < 0.0001). The quality of life assessed by World Health Organization Quality of Life-BREF (WHOQOL-BREF) questionnaire was reported to be "good" or "neither good nor bad" by majority of the participants at baseline and after 3 months of treatment. A total of 15 adverse events (AEs) were reported in the study, however, no serious adverse event (SAE) occurred during the study. All AEs were of mild intensity and did not require any intervention.

CONCLUSION

Overall, saxagliptin in combination with metformin was generally well tolerated in Indian T2DM patients and new safety event identified is an increased risk of hospitalisation in heart failure patients. This study is also registered on Clinicaltrials.gov (NCT02588859).

Using DPP-4 inhibitors to modulate beta cell function in type 1 diabetes and in the treatment of diabetic kidney disease

INTRODUCTION

DPP-4 inhibitors have pleomorphic effects that extend beyond the anti-hyperglycemic labeled use of the drug. DPP-4 inhibitors have demonstrated promising renal protective effects in T2DM and T1DM and protective effects against immune destruction of pancreatic beta-cells in T1DM.

AREAS COVERED

The efficacy of DPP-4 inhibitors in the treatment of diabetic kidney disease and possible adjunct with insulin in the treatment of T1DM to preserve beta-cell function. Pertinent literature was identified through Medline, PubMed and ClinicalTrials.gov (1997-November 2018) using the search terms T1DM, sitagliptin, vildagliptin, linagliptin, beta-cell function, diabetic nephropathy. Only articles are written in the English language, and clinical trials evaluating human subjects were used.

EXPERT OPINION

DPP-4 inhibitors can be used safely in patients with diabetic kidney disease and do not appear to exacerbate existing diabetic nephropathy. Linagliptin reduces albuminuria and protects renal endothelium from the deleterious effects of hyperglycemia. The effects of DPP-4 inhibitors on preserving beta-cell function in certain subtypes of T1DM [e.g. Latent Autoimmune Diabetes in Adult (LADA) and Slowly Progressive Type 1 Diabetes (SPIDDM)] are encouraging and show promise.

Management of hypoglycemia in older adults with type 2 diabetes

Treatment of older adults with type 2 diabetes (T2D) is complex because they represent a heterogeneous group with a broad range of comorbidities, functional abilities, socioeconomic status, and life expectancy. Older adults with T2D are at high risk of recurring hypoglycemia, a condition associated with marked morbidity and mortality, because their counter-regulatory mechanism to hypoglycemia is attenuated, and recurring hypoglycemic episodes can lead to hypoglycemia unawareness. In addition, polypharmacy, a result of multiple chronic comorbidities (including heart disease, stroke, and chronic kidney disease), can increase the risk of severe hypoglycemia, especially when patients are taking sulfonylureas or insulin. Often the signs of hypoglycemia are nonspecific (sweating, dizziness, confusion, visual disturbances) and are mistaken for neurological symptoms or dementia. Consequences of hypoglycemia include acute and long-term cognitive changes, cardiac arrhythmia and myocardial infarction, serious falls, frailty, and death, often resulting in hospitalization, which come at a high economic cost. The American Diabetes Association has recently added three new recommendations regarding hypoglycemia in the elderly, highlighting individualized pharmacotherapy with glucose-lowering agents with a low risk of hypoglycemia and proven cardiovascular safety, avoidance of overtreatment, and simplifying treatment regimens while maintaining HbA1c targets. Thus, glycemic goals can be relaxed in the older population as part of individualized care, and physicians must make treatment decisions that best serve their patients' circumstances. This article highlights the issues faced by older people with T2D, the risk factors for hypoglycemia in this population, and the challenges faced by health care providers regarding glycemic management in this patient group.

Prescription of DPP-4 Inhibitors to Patients With Adult Type 2 Diabetes Mellitus and Creatinine Clearance >50 mL/min: The UK Primary Care Experience

The aim of the study was to examine the extent to which patients with type 2 diabetes mellitus (T2DM) initiating a dipeptidyl peptidase 4 (DPP-4) inhibitor, who had no recorded objective evidence to justify dose adjustment, were initiated on the manufacturer-specified dose. Adopting a cross-sectional study design and using data from the UK General Practice, this study showed that at least 10% of patients with T2DM and a creatinine clearance level >50 mL/min initiating treatment with a DPP-4 inhibitor were prescribed a dose lower than specified in the Summary of Product Characteristics. This study provides further insights regarding DPP-4 inhibitor dose selection with respect to manufacturer specification in relation to renal function.

Safety and Efficacy of Teneligliptin in Patients with Type 2 Diabetes Mellitus and Impaired Renal Function: Interim Report from Post-marketing Surveillance

INTRODUCTION

Teneligliptin is a novel oral dipeptidyl peptidase-4 inhibitor for the treatment of type 2 diabetes mellitus (T2DM). Safety and efficacy of teneligliptin have been demonstrated in clinical studies; however, data supporting its use in patients with moderate or severe renal impairment are limited. This interim analysis of a post-marketing surveillance of teneligliptin, exploRing the long-term efficacy and safety included cardiovascUlar events in patients with type 2 diaBetes treated bY teneligliptin in the real-world (RUBY), aims to verify the long-term safety and efficacy of teneligliptin in Japanese patients with T2DM and impaired renal function.

METHODS

For this analysis, we used the data from case report forms of the RUBY surveillance between May 2013 and June 2017. The patients were classified into G1-G5 stages of chronic kidney disease according to estimated glomerular filtration rate (eGFR) at initiation of teneligliptin treatment. Safety and efficacy were evaluated in these subgroups. Patients on dialysis were also assessed. Safety was assessed from adverse drug reactions (ADRs). Glycemic control was evaluated up to 2 years after teneligliptin initiation.

RESULTS

A total of 11,677 patients were enrolled in the surveillance and 11,425 patient case-report forms were collected for the interim analysis. The incidence of ADRs in each subgroup was 2.98-6.98% of patients, with no differences in the ADR profile (including hypoglycemia and renal function ADRs) between subgroups. At 1 and 2 years after starting teneligliptin, the least-squares mean change in HbA1c adjusted to the baseline was - 0.68 to - 0.85% and - 0.71 to - 0.85% across the eGFR groups, respectively. Treatment with teneligliptin in patients on dialysis reduced or tended to reduce glycated albumin levels [- 2.29%, (p < 0.001) after 1 year; - 1.64%, (p = 0.064) after 2 years].

CONCLUSIONS

During long-term treatment, teneligliptin was generally well tolerated in patients with any stage of renal impairment from normal to end-stage renal disease, including those on dialysis, and improved glycemic control.

TRIAL REGISTRATION NUMBER

Japic CTI-153047.

FUNDING

Mitsubishi Tanabe Pharma Corporation and Daiichi Sankyo Co, Ltd.

When metformin is not enough: Pros and cons of SGLT2 and DPP-4 inhibitors as a second line therapy

The newer oral therapies for type 2 diabetes mellitus, dipeptidyl peptidase-4 (DPP-4) inhibitors and sodium glucose cotransporter 2 (SGLT2) inhibitors, have advantages over older agents. Dipeptidyl peptidase-4 inhibitors are weight neutral and have few adverse effects. Sodium glucose cotransporter 2 inhibitors have additional benefits: weight loss, blood pressure reduction, cardiovascular risk reduction, and renoprotective effects. Sodium glucose cotransporter 2 inhibitors have increased risk of urogenital infections and possible risk of "euglycaemic" diabetic ketoacidosis. It is important to balance the benefits over the older-oral therapies as these agents are more expensive; yet some analyses suggest that they are within the limits of what is considered cost-effective in health care. We discuss the relative merits and drawbacks of these 2 classes and consider their roles in the treatment of type 2 diabetes mellitus. We suggest a number of patient profiles where early use of these agents could be used. We favour the use of SGLT2 inhibitors over DPP-4 inhibitors as add on therapy to metformin when glycaemic targets have not been achieved given their similar glycaemic efficacy and the additional benefits of SGLT2 inhibitors. We particularly favour SGLT2 inhibitors in those where additional weight loss and blood pressure reductions are desired, and in patients with heart failure or cardiovascular disease. Care should be taken to warn patients about genital fungal infections and to avoid use in people with risk factors for SGLT2 associated ketoacidosis. We favour DPP-4 inhibitors in those where side effects of other agents are of concern, the frail elderly population, and those with renal disease precluding SGTL2 inhibitor use.

Aerobic exercise regulates blood lipid and insulin resistance via the toll‑like receptor 4‑mediated extracellular signal‑regulated kinases/AMP‑activated protein kinases signaling pathway

Diabetes mellitus is a complicated metabolic disease with symptoms of hyperglycemia, insulin resistance, chronic damage and dysfunction of tissues, and metabolic syndrome for insufficient insulin production. Evidence has indicated that exercise treatments are essential in the progression of type‑ІІ diabetes mellitus, and affect insulin resistance and activity of islet β‑cells. In the present study, the efficacy and signaling mechanism of aerobic exercise on blood lipids and insulin resistance were investigated in the progression of type‑ІІ diabetes mellitus. Body weight, glucose metabolism and insulin serum levels were investigated in mouse models of type‑ІІ diabetes mellitus following experienced aerobic exercise. Expression levels of inflammatory factors, interleukin (IL)‑6, high‑sensitivity C‑reactive protein, tumor necrosis factor‑α and leucocyte differentiation antigens, soluble CD40 ligand in the serum were analyzed in the experimental mice. In addition, expression levels of toll‑like receptor 4 (TLR‑4) were analyzed in the liver cells of experimental mice. Changes of oxidative stress indicators, including reactive oxygen species, superoxide dismutase, glutathione and catalase were examined in the liver cells of experimental mice treated by aerobic exercise. Expression levels and activity of extracellular signal‑regulated kinases (ERK) and AMP‑activated protein kinase (AMPK) signaling pathways were investigated in the liver cells of mouse models of type‑ІІ diabetes mellitus after undergoing aerobic exercise. Aerobic exercise decreased the expression levels of inflammatory factors in the serum of mouse models of type‑ІІ diabetes mellitus. The results indicated that aerobic exercise downregulated oxidative stress indicators in liver cells from mouse models of type‑ІІ diabetes mellitus. In addition, the ERK and AMPK signaling pathways were inactivated by aerobic exercise in liver cells in mouse models of type‑ІІ diabetes mellitus. The activity of ERK and AMPK, and the function of islet β‑cells were observed to be improved in experimental mice treated with aerobic exercise. Furthermore, blood lipid metabolism and insulin resistance were improved by treatment with aerobic exercise. Body weight and glucose concentration of serology was markedly improved in mouse models of type‑ІІ diabetes mellitus. Furthermore, TLR‑4 inhibition markedly promoted ERK and AMPK expression levels and activity. Thus, these results indicate that aerobic exercise may improve blood lipid metabolism, insulin resistance and glucose plasma concentration in mouse models of type‑ІІ diabetes mellitus. Thus indicating aerobic exercise is beneficial for improvement of blood lipid and insulin resistance via the TLR‑4‑mediated ERK/AMPK signaling pathway in the progression of type‑ІІ diabetes mellitus.

The safety of gliptins : updated data in 2018

INTRODUCTION

Dipeptidyl peptidase-4 inhibitors (DPP-4is) are generally considered as glucose-lowering agents with a safe profile in type 2 diabetes.

AREAS COVERED

An updated review of recent safety data from randomised controlled trials, observational studies, meta-analyses, pharmacovigilance reports regarding alogliptin, linagliptin, saxagliptin, sitagliptin, and vildagliptin, with a special focus on risks of hypoglycemia, pancreatitis and pancreatic cancer, major cardiovascular events, hospitalisation for heart failure and other new safety issues, such as bone fractures and arthralgia. The safety of DPP-4i use in special populations, elderly patients, patients with renal impairment, liver disease or heart failure, will also be discussed.

EXPERT OPINION

The good tolerance/safety profile of DPP-4is has been largely confirmed, including in more fragile populations, with no gastrointestinal adverse effects and a minimal risk of hypoglycemia. DPP-4is appear to be associated with a small increased incidence of acute pancreatitis in placebo-controlled trials, although most observational studies are reassuring. Most recent studies with DPP-4is do not confirm the increased risk of hospitalisation for heart failure reported with saxagliptin in SAVOR-TIMI 53, but further post-marketing surveillance is still recommended. New adverse events have been reported such as arthralgia, yet a causal relationship remains unclear.

Renal outcomes with dipeptidyl peptidase-4 inhibitors

Dipeptidyl peptidase-4 inhibitors (DPP-4is) are increasingly being used in the management of type 2 diabetes (T2D). The present review summarizes the current knowledge of the effects of DPP-4is on renal outcomes by analyzing the experimental preclinical data, the effects of DPP-4is on urinary albumin-creatinine ratios (UACRs) and estimated glomerular filtration rates (eGFRs) from observational studies and clinical trials, and renal events (including kidney failure requiring renal replacement therapy) in recent large prospective cardiovascular outcome trials. Renal protection has been demonstrated in various animal models that have implicated different underlying mechanisms independent of glucose control, whereas prevention of new onset microalbuminuria and/or progression of albuminuria has been reported in some clinical studies, but with no significant effects on eGFR in most of them. The long-term clinical effects of DPP-4is on renal outcomes and the development of end-stage renal disease remain largely unknown and, thus, demand further investigations in prospective trials and long-term observational studies. In conclusion, despite promising results in animal models, data on surrogate biological markers of renal function and clinical renal outcomes remain rather scanty in patients with T2D, and mostly demonstrate the safety rather than true efficacy of DPP-4is.

The Use of Saxagliptin in People with Type 2 Diabetes in France: The Diapazon Epidemiological Study

INTRODUCTION

Saxagliptin is a potent, reversible inhibitor of dipeptidyl peptidase-4 that is indicated for the treatment of type 2 diabetes. The DIAPAZON study was a multicenter observational study intended to document the effectiveness, safety and patterns of saxagliptin use in France, including the saxagliptin retention rate, over 2 years of follow-up.

METHODS

A geographically representative sample of 304 French physicians (general practitioners and specialist endocrinologists or diabetologists) recruited 1131 adults with type 2 diabetes into an ambispective cohort; 1033 fulfilled the inclusion criteria. All had started saxagliptin during the previous 6 months or at study inclusion, and follow-up was for 24 ± 3 months after starting saxagliptin.

RESULTS

The mean age of the study population when starting saxagliptin was 61 years, and the mean HbA1c level was 8.0%; 79% had an HbA1c level ≥7%. Prior to starting saxagliptin treatment, most participants (91%) were receiving treatment with oral glucose-lowering drugs alone. The most commonly prescribed regimen at starting saxagliptin (53% of participants) was a combination of saxagliptin and metformin. The overall saxagliptin retention rate at 2 years was 79%, as estimated by the Kaplan-Meier method. The most common reasons for discontinuation were inadequate glycemic control (52%) and intolerance (22%). During the course of the study, the mean HbA1c level decreased to 7.0%, and the percentage of people with HbA1c <7% increased from 21% to 49%. The mean change in body weight was -1.8 kg. A total of 294 hypoglycemic episodes were reported in 70 participants (6.8%) during the follow-up period. Of these, 143 episodes in 41 participants (4.0%) occurred when saxagliptin was used in combination with agents associated with hypoglycemia, such as insulin, sulfonylureas or glinides.

CONCLUSION

Saxagliptin is efficacious and well tolerated in a real-world practice setting, with almost 80% of participants remaining on treatment after 2 years.

FUNDING

AstraZeneca, France.

Dipeptidyl Peptidase-4 Inhibitor Development and Post-authorisation Programme for Vildagliptin - Clinical Evidence for Optimised Management of Chronic Diseases Beyond Type 2 Diabetes

The last decade has witnessed the role of dipeptidyl peptidase-4 (DPP-4) inhibitors in producing a conceptual change in early management of type 2 diabetes mellitus (T2DM) by shifting emphasis from a gluco-centric approach to holistically treating underlying pathophysiological processes. DPP-4 inhibitors highlighted the importance of acknowledging hypoglycaemia and weight gain as barriers to optimised care in T2DM. These complications were an integral part of diabetes management before the introduction of DPP-4 inhibitors. During the development of DPP-4 inhibitors, regulatory requirements for introducing new agents underwent substantial changes, with increased emphasis on safety. This led to the systematic collection of adjudicated cardiovascular (CV) safety data, and, where 95% confidence of a lack of harm could not be demonstrated, the standardised CV safety studies. Furthermore, the growing awareness of the worldwide extent of T2DM demanded a more diverse approach to recruitment and participation in clinical trials. Finally, the global financial crisis placed a new awareness on the health economics of diabetes, which rapidly became the most expensive disease in the world. This review encompasses unique developments in the global landscape, and the role DPP-4 inhibitors, specifically vildagliptin, have played in research advancement and optimisation of diabetes care in a diverse population with T2DM worldwide.

A network meta-analysis for efficacy and safety of seven regimens in the treatment of type II diabetes

The efficacy and safety of seven regimens based on metformin (placebo plus metformin, dapagliflozin plus metformin, vildagliptin plus metformin, saxagliptin plus metformin, empagliflozin plus metformin, exenatide plus metformin and sitagliptin plus metformin) on type 2 diabetes (T2D) were compared based on network meta-analysis. PubMed, Embase and Cochrane Library were applied in the computer-based retrieval process. Randomized controlled trials (RCTs) which were related with the above seven regimens based on metformin in the treatment of T2D were included in this study. Network meta-analysis merged the direct and indirect comparison evidence for the estimation of the weighted mean difference (WMD), odd ratios (ORs) and surface under the cumulative sequencing ranking curve (SUCRA) values. Eight eligible RCTs were applied in this network meta-analysis. The results demonstrated that: in terms of efficacy, the glycated hemoglobin (HbA1c) levels of T2D patients receiving vildagliptin plus metformin were relatively lower when compared with placebo plus metformin (WMD=-1.95, 95%CI=-3.70--0.23); in comparison with exenatide plus metformin, the triglyceride level in T2D patients taking vildagliptin plus metformin remained relatively lower (WMD=-1.36, 95%CI=-2.64--0.01). In terms of safety, the rate of adverse events in patients with T2D who received empagliflozin plus metformin was relatively lower when compared with saxagliptin plus metformin (OR=0.37, 95%CI=0.14-0.98). Furthermore, the SUCRA value of vildagliptin plus metformin was comparatively higher in efficacy, and that the SUCRA value of saxagliptin plus metformin was relatively lower in safety. The efficacy of vildagliptin plus metformin in patients with T2D is relatively better, while the safety of saxagliptin plus metformin in patients with T2D is relatively poorer.

[Vildagliptin suppresses temporal lobe epilepsy by up-regulating glucagon-like peptide-1]

OBJECTIVE

To investigate the effect of vildagliptin on pentamethazol (PTZ)-induced epilepsy in rats and explore the molecular mechanism.

METHODS

Samples of temporal cortex from 23 patients with temporal lobe epilepsy were collected as epilepsy group and samples of temporal cortex from 14 patients with brain trauma were used as control group. Ninety male SD rats were randomly divided into control group (group A), PTZ-induced epilepsy group (group B), saline 2 mL/kg group (group C), vildagliptin 2.5 mg/kg group (group D), vildagliptin 5mg/kg group (group D) and vildagliptin 10 mg/kg group (group F). Use chronic model of epilepsy induced by PTZ (35 mg/kg) intraperitoneal injection for 3 consecutive weeks, and changes of behavior were observed. The expression of GLP-1R was detected by Western blotting and immunohistochemical (IHC) staining, and the expression of GLP-1 was detected by enzyme-linked immunosorbent assay (ELISA). The location of GLP-1R was detected by immunofluorescent staining.

RESULTS

Immunofluorescent staining showed that the GLP-1R located in the neurons, and GLP-1R expression was obviously decreased both in patients with TLE and in rats with epilepsy. The latency time was prolonged and epilepsy attack time was decreased after vildagliptin treatment (P<0.05). GLP-1R expression was increased after vildagliptin treatment (P<0.05). ELISA showed the change of GLP-1 expression was the same as GLP-1R.

CONCLUSION

Vildagliptin can suppress temporal lobe epilepsy in rats by up-regulating GLP-1 and GLP-1R expressions.

Visceral hypersensitivity in inflammatory bowel diseases and irritable bowel syndrome: The role of proteases

Proteases, enzymes catalyzing the hydrolysis of peptide bonds, are present at high concentrations in the gastrointestinal tract. Besides their well-known role in the digestive process, they also function as signaling molecules through the activation of protease-activated receptors (PARs). Based on their chemical mechanism for catalysis, proteases can be classified into several classes: serine, cysteine, aspartic, metallo- and threonine proteases represent the mammalian protease families. In particular, the class of serine proteases will play a significant role in this review. In the last decades, proteases have been suggested to play a key role in the pathogenesis of visceral hypersensitivity, which is a major factor contributing to abdominal pain in patients with inflammatory bowel diseases and/or irritable bowel syndrome. So far, only a few preclinical animal studies have investigated the effect of protease inhibitors specifically on visceral sensitivity while their effect on inflammation is described in more detail. In our accompanying review we describe their effect on gastrointestinal permeability. On account of their promising results in the field of visceral hypersensitivity, further research is warranted. The aim of this review is to give an overview on the concept of visceral hypersensitivity as well as on the physiological and pathophysiological functions of proteases herein.