The safety of gliptins : updated data in 2018

Heart Failure: A Palliative Medicine Review of Disease, Therapies, and Medications With a Focus on Symptoms, Function, and Quality of Life

Despite significant advances in heart failure (HF) treatment, HF remains a progressive, extremely symptomatic, and terminal disease with a median survival of 2.1 years after diagnosis. HF often leads to a constellation of symptoms, including dyspnea, fatigue, depression, anxiety, insomnia, pain, and worsened cognitive function. Palliative care is an approach that improves the quality of life of patients and their caregivers facing the problems associated with life-threatening illness and therefore is well suited to support these patients. However, historically, palliative care has often focused on supporting patients with malignant disease, rather than a progressive chronic disease such as HF. Predicting mortality in patients with HF is challenging. The lack of obvious transition points in disease progression also raises challenges to primary care providers and specialists to know at what point to integrate palliative care during a patient's disease trajectory. Although therapies for HF often result in functional and symptomatic improvements including health-related quality of life (HRQL), some patients with HF do not demonstrate these benefits, including those patients with a preserved ejection fraction. Provision of palliative care for patients with HF requires an understanding of HF pathogenesis and common medications used for these patients, as well as an approach to balancing life-prolonging and HRQL care strategies. This review describes HF and current targeted therapies and their effects on symptoms, hospital admission rates, exercise performance, HRQL, and survival. Pharmacological interactions with and precautions related to commonly used palliative care medications are reviewed. The goal of this review is to equip palliative care clinicians with information to make evidence-based decisions while managing the balance between optimal disease management and patient quality of life.

Metabolism of GIP and the contribution of GIP to the glucose-lowering properties of DPP-4 inhibitors

Glucose-dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone with insulinotropic and glucagonotropic actions, and is believed to be the more physiologically important incretin hormone in healthy humans. Together with the other incretin hormone, glucagon-like peptide-1 (GLP-1), it plays an important role in regulating glucose homeostasis. Both GLP-1 and GIP are substrates of the enzyme dipeptidyl peptidase-4 (DPP-4), and DPP-4 inhibitors, which potentiate their effects on glycaemic control, are now used to treat type 2 diabetes (T2D). This review describes how post-translational processing of the GIP precursor molecule and post-release degradation of the secretory products give rise to multiple isoforms of GIP, some, but not all of which are biologically active, and discusses how this impacts upon their measurement by immunological- and bioassay-based methods. DPP-4 inhibitors reduce degradation of GIP, and although the insulinotropic effects of GIP are impaired in patients with T2D, they can be at least partially restored if glycaemic control is improved. Therefore, given that studies with incretin receptor antagonists indicate that not all of the glucose-lowering effects of DPP-4 inhibition can be accounted for by GLP-1 alone, evidence supports the notion that GIP may play a role in mediating the anti-hyperglycaemic effects of DPP-4 inhibition, while its glucagonotropic actions at lower glucose levels may contribute to the low risk of hypoglycaemia associated with DPP-4 inhibitors.

Dipeptidyl Peptidase-4 Is a Target Protein of Epigallocatechin-3-Gallate

Epigallocatechin-3-gallate (EGCG), a major active ingredient in green tea, has various health benefits. It affects glucose metabolism, but the mechanism is not well understood. This study aimed to identify targets of EGCG related to glucose metabolism. The core fragment of EGCG is a flavonoid. The flavonoid scaffold was used as a substructure to find proteins cocrystallized with flavonoids in the Protein Data Bank. The proteins identified were screened in PubMed for known relationships with diabetes. Dipeptidyl peptidase-4 (DPP4; PDB 5J3J) was identified following this approach. By molecular docking, the interactions of EGCG and DPP4 were assessed. To test the stability of the interactions between EGCG and DPP4, molecular dynamics simulation for 100 ns was performed using Desmond software. In vitro, the concentration of EGCG required to inhibit DPP4 activity by 50% (the IC50 value) was 28.42 μM. These data provide a theoretical basis for intervention in glucose metabolism with EGCG.

Reduction in HbA1c with SGLT2 inhibitors vs. DPP-4 inhibitors as add-ons to metformin monotherapy according to baseline HbA1c: A systematic review of randomized controlled trials

AIMS

This study compared the reduction of glycated haemoglobin (HbA1c) with sodium-glucose cotransporter type-2 inhibitors (SGLT2is) vs. dipeptidyl peptidase-4 inhibitors (DPP-4is) as add-ons to metformin in patients with type 2 diabetes mellitus (T2DM), with a specific focus on HbA1c changes according to baseline HbA1c.

MATERIALS AND METHODS

Electronic databases were scrutinized for randomized controlled trials (RCTs) evaluating the reduction of HbA1c from baseline (Δ HbA1c) with an SGLT2i or DPP-4i in patients with T2DM not well controlled by metformin monotherapy. The endpoint was Δ HbA1c using both indirect and direct comparisons.

RESULTS

Overall, Δ HbA1c was slightly greater with SGLT2is (-0.80±0.20% from 8.03±0.35%; 44 analyses, 29 RCTs, 15 with two doses, n=9321) than with DPP-4is (-0.71±0.23% from 8.05±0.43%; 61 analyses, 59 RCTs, n=17,914; P=0.0354). When the mean baseline HbA1c was<8% ([64mmol/mol] 7.79±0.15% vs. 7.71±0.23%), Δ HbA1c averaged -0.735±0.17% vs. -0.62±0.16% (P=0.0117) with SGLT2is vs. DPP-4is, respectively. However, this difference vanished when the mean baseline HbA1c was≥8% (-0.87±0.22% from 8.27±0.32% with SGLT2is vs. -0.80±0.24% from 8.35±0.33% with DPP-4is; P=0.2756). The relationship between Δ HbA1c and baseline HbA1c was only slightly stronger with SGLT2is (slope: -0.39, r²=-0.43; P<0.0001) than with DPP-4is (slope: -0.26, r²=-0.25; P<0.0001).

CONCLUSION

Because of the small difference in Δ HbA1c whatever the baseline HbA1c level with SGLT2is vs. DPP-4is as add-ons to metformin, choosing between these glucose-lowering agents in clinical practice should be based on other efficacy criteria (such as weight and blood pressure changes, cardiovascular and renal protection) or on safety profiles rather than on HbA1c levels.

Myopathy with DPP-4 inhibitors and statins in the real world: investigating the likelihood of drug-drug interactions through the FDA adverse event reporting system

AIMS

To investigate the occurrence of myopathy with oral glucose-lowering drugs (OGLDs) and statins, with a focus on dipeptidyl peptidase-4 inhibitors (DPP4-is).

METHODS

The FDA adverse event reporting system (FAERS) was queried (2004-2016) to compare the proportion of adverse events with OGLDs, alone and in combination with statins, using the reporting odds ratio (ROR) with relevant 95% confidence interval (95%Cl), adjusted for sex, age and concomitant presence of other OGLDs/lipid-lowering drugs. Drug-drug interaction is claimed whenever the frequency of an event is enhanced by combination treatment. Consistency/robustness of findings was tested by applying additive/multiplicative models and accounting for competition bias (i.e., adverse events previously known to be associated with OGLDs were removed).

RESULTS

Over a 13-year period, we retrieved 142,888 cases of myopathy. The use of DPP4-is alone was not associated with higher reporting of myopathy (no. of cases = 4898; adjusted ROR = 1.00; 95%CI = 0.96-1.04), with the notable exclusion of vildagliptin (262; 1.64; 1.42-1.88). No increased occurrence emerged when used in combination with statins, with consistent findings from additive/multiplicative models for all DPP4-is. Likewise, no increased reporting was found for other OGLDs (28,964; 0.64; 0.62-0.67); data on the interaction with statins were consistent/robust across analyses only for sulfonylureas (the interaction is likely and biologically plausible) and sodium glucose cotransporter-2 inhibitors.

CONCLUSIONS

Real-world FAERS data do not raise concern for muscular toxicity with DPP4-is in combination with statins, making a drug interaction very unlikely.

Synthesis of vildagliptin conjugated metal nanoparticles for type II diabetes control: targeting the DPP-IV enzyme

Diabetes is one of the most prevalent diseases worldwide.

Series: Implications of the recent CVOTs in type 2 diabetes: Impact on guidelines: The endocrinologist point of view

The management of type 2 diabetes mellitus (T2DM) essentially consists in controlling hyperglycaemia, together with other vascular risk factors, in order to reduce the incidence and severity of diabetic complications. Whereas glucose control using classical glucose-lowering agents (except perhaps metformin) largely fails to reduce cardiovascular disease (CVD), two new pharmacological classes, glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter type 2 inhibitors (SGLT2is), have proven their ability to reduce major cardiovascular events in patients with established CVD. Furthermore, SGLT2is reduced the risk of hospitalisation for heart failure and the progression of renal disease. According to the 2018 ADA-EASD consensus report, the choice of a second agent to be added to metformin should now be driven by the presence or not of atherosclerotic CVD, heart failure or renal disease, all conditions that should promote the use of a SGLT2i or a GLP-1 RA with proven efficacy. Thus endocrinologists have to face a new paradigm in the management of T2DM, with a shift from a primary objective of glucose control without inducing hypoglycaemia and weight gain to a goal of cardiovascular and renal protection, largely independent of glucose control. Of note, however, the latter remains crucial to reduce the risk of microangiopathy.

Association of glycemic variability with left ventricular diastolic function in type 2 diabetes mellitus

Background

Type 2 diabetes mellitus (T2DM) is a major cause of heart failure (HF) with preserved ejection fraction (HFpEF), usually presenting as left ventricular (LV) diastolic dysfunction. Thus, LV diastolic function should be considered a crucial marker of a preclinical form of DM-related cardiac dysfunction. However, the impact of glycemic variability (GV) on LV diastolic function in such patients remains unclear.

Methods

We studied 100 asymptomatic T2DM patients with preserved LV ejection fraction (LVEF) without coronary artery disease (age: 60 ± 14 years, female: 45%). GV was evaluated as standard deviation of blood glucose level using continuous glucose monitoring system for at least 72 consecutive hours. LV diastolic function was defined as mitral inflow E and mitral e’ annular velocities (E/e’), and > 14 was determined as abnormal.

Results

E/e’ in patients with high GV (≥ 35.9 mg/dL) was significantly higher than that in patients with low GV (11.3 ± 3.9 vs. 9.8 ± 2.8, p = 0.03) despite similar age, gender-distribution, and hemoglobin A1c (HbA1c). Multivariate logistic regression analysis showed that GV ≥ 35.9 mg/dL (odds ratio: 3.67; 95% confidence interval: 1.02–13.22; p < 0.05) was an independently associated factor, as was age, of E/e’ > 14. In sequential logistic models for the associations of LV diastolic dysfunction, one model based on clinical variables including age, gender and hypertension was not improved by addition of HbA1c (p = 0.67) but was improved by addition of high GV (p = 0.04).

Conclusion

Since HFpEF is a syndrome caused by diverse agents, reducing GV may represent a potential new therapeutic strategy for the prevention of the development of HFpEF in T2DM patients.

Benefit-Risk Assessment of Alogliptin for the Treatment of Type 2 Diabetes Mellitus

The dipeptidyl peptidase-4 inhibitor (DPP-4i) alogliptin is an oral, antidiabetic treatment that is approved in many countries to treat patients with type 2 diabetes mellitus (T2DM), including the USA, Europe, and Japan. Alogliptin is efficacious both as monotherapy and as add-on/combination therapy with other commonly prescribed T2DM treatments, such as metformin and pioglitazone. Overall, alogliptin is well-tolerated in patients with T2DM, including older patients, those with renal and/or hepatic impairment, and those at high risk of cardiovascular events. There is a low risk of hypoglycemia, weight gain, acute pancreatitis, and gastrointestinal adverse events with alogliptin treatment, as demonstrated in long-term trials (lasting up to 4.5 years) and in a real-world setting. Additionally, alogliptin has a generally favorable or similar safety profile in comparison to other antidiabetic agents (metformin, thiazolidinediones, sulfonylureas, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors, α-glucosidase inhibitors, and insulin). However, further evaluation would be required to determine the mechanism and effect of alogliptin on heart failure, bullous pemphigoid, and inflammatory bowel disease. Of note, due to the ethnic diversity in the epidemiology of T2DM, alogliptin has been shown to be more efficacious in Asian patients than in non-Asian patients with T2DM, but with a similar tolerability profile. These data indicate that DPP-4is, including alogliptin, are important treatment options, especially for Asian patients with T2DM, for whom they have potential as a first-line therapy. This benefit-risk assessment aims to place alogliptin within the current armamentarium of T2DM and aid physicians when choosing optimal diabetes treatment for their patients.

Optimization of the benzamide fragment targeting the S2' site leads to potent dipeptidyl peptidase-IV inhibitors

Our recently successful identification of benzoic acid-based DPP-4 inhibitors spurs the further quest for in-depth structure-activity relationships (SAR) study in S₂' site DPP-4. Thus novel benzamide fragments were designed to target the S₂' site to compromise lipophilicity and improve oral activity. Exploring SAR by introduction of a variety of amide and halogen on benzene ring led to identification of several compounds, exerting moderated to excellent DPP-4 activities, in which 4'-chlorine substituted methyl amide 17g showed most potent DPP-4 activity with the IC₅₀ value of 1.6 nM. Its activity was superior to reference alogliptin. Docking study ideally verified and interpreted the obtained SAR of designed compounds. As a continuation, DPP-8/9 assays revealed the designed compounds exhibited good selectivity over DPP-8 and DPP-9. Subsequent cell-based test indicated compound 17g displayed low toxicity toward the LO2 cell line up to 100 μM. In vivo evaluation showed compound 17g robustly improved the glucose tolerance in normal mice. Importantly, 17g exhibited reasonable pharmacokinetic (PK) profiles for oral delivery. Overall, compound 17g has the potential to a safe and efficacious DPP-4 inhibitor for T2DM treatment.

From NASH to diabetes and from diabetes to NASH: Mechanisms and treatment options

The worldwide prevalence of non-alcoholic fatty liver disease (NAFLD) is estimated to have reached 25% or more in adults. NAFLD is prevalent in obese individuals, but may also affect non-obese insulin-resistant individuals. NAFLD is associated with a 2- to 3-fold increased risk of developing type 2 diabetes (T2D), which may be higher in patients with more severe liver disease - fibrosis increases this risk. In NAFLD, not only the close association with obesity, but also the impairment of many metabolic pathways, including decreased hepatic insulin sensitivity and insulin secretion, increase the risk of developing T2D and related comorbidities. Conversely, patients with diabetes have a higher prevalence of steatohepatitis, liver fibrosis and end-stage liver disease. Genetics and mechanisms involving dysfunctional adipose tissue, lipotoxicity and glucotoxicity appear to play a role. In this review, we discuss the altered pathophysiological mechanisms that underlie the development of T2D in NAFLD and vice versa. Although there is no approved therapy for the treatment of NASH, we discuss pharmacological agents currently available to treat T2D that could potentially be useful for the management of NASH.

A population-based analysis of antidiabetic medications in four Canadian provinces: Secular trends and prescribing patterns

PURPOSE

To use the Canadian Network for Observational Drug Effect Studies (CNODES) to describe drug utilization of antidiabetic medications in four Canadian provinces.

METHODS

With the use of data from CNODES, we constructed cohorts of patients with type 2 diabetes in four Canadian provinces (Manitoba, Ontario, Quebec, and Saskatchewan) who received their first-ever prescription for a noninsulin antidiabetic medication during the study period, defined as the earliest date of data availability in each province (range: 1993-1998) to the latest date of the data extraction in each province (range: 2013-2014). Prescriptions rates were calculated for all prescriptions by class and described over time.

RESULTS

Across provinces, we identified 650 830 patients who initiated antidiabetic medications during the study period. In most provinces, the overall prescription rate of antidiabetic medications increased during the last two decades. Metformin particularly increased in popularity, surpassing sulfonylureas in all provinces as the most widely prescribed antidiabetic medication by the early 2000s. Thiazolidinediones grew in popularity from the onset of their availability until 2006 to 2007, at which point they rapidly declined. Dipeptidyl peptidase-4 inhibitors saw substantial growth in several provinces following their addition to provincial formularies in 2008 to 2012, while glucagon-like peptide-1 agonists experienced modest growth. Insulin prescription rates remained constant or steadily increased over the last two decades.

CONCLUSIONS

CNODES can be used for cross-jurisdictional drug utilization studies. In Canada, trends in antidiabetic medication prescriptions followed changing guidelines reflecting up-to-date knowledge of drug effectiveness and safety.

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.

From the Incretin Concept and the Discovery of GLP-1 to Today's Diabetes Therapy

Researchers have been looking for insulin-stimulating factors for more than 100 years, and in the 1960ties it was definitively proven that the gastrointestinal tract releases important insulinotropic factors upon oral glucose intake, so-called incretin hormones. The first significant factor identified was the duodenal glucose-dependent insulinotropic polypeptide, GIP, which however, turned out not to stimulate insulin secretion in patients with type 2 diabetes. But resection experiments clearly indicated the presence of an additional incretin, and in 1986, an unexpected processing fragment of the recently identified glucagon precursor, proglucagon, namely truncated glucagon-like peptide 1 (GLP-1 7-36 amide), was isolated from the gut and found to both stimulate insulin secretion and inhibit glucagon secretion. The peptide also inhibited appetite and food intake. Unlike GIP, this peptide had preserved effects in patients with type 2 diabetes and it was soon documented to have powerful antidiabetic effects in clinical studies. Its utility was limited, however, because of an extremely short half-life in humans, but this problem had two solutions, both of which gave rise to important antidiabetic drugs: (1) orally active inhibitors of the enzyme dipeptidylpeptidase 4 (DPP-4 inhibitors), which was responsible for the rapid degradation; the inhibitors protect endogenous GLP-1 from degradation and thereby unfold its antidiabetic activity, and (2) long-acting injectable analogs of GLP-1 protected against DPP-4 degradation. Particularly, the latter, the GLP-1 receptor agonists, either alone or in various combinations, are so powerful that treatment allows more than 2/3 of type 2 diabetes patients to reach glycemic targets. In addition, these agents cause a weight loss which, with the most successful compounds, may exceed 10% of body weight. Most recently they have also been shown to be renoprotective and reduce cardiovascular risk and mortality.

An update on the safety of SGLT2 inhibitors

INTRODUCTION

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are recommended after metformin for a large spectrum of patients with type 2 diabetes, because of a favorable benefit/risk profile despite a variety of adverse events.

AREAS COVERED

This narrative review discusses the safety profile of SGLT2is: initial concerns (cardiovascular safety, acute renal failure, hypoglycemia, urinary and genital infections, volume depletion, bladder cancer), further concerns (euglycemic ketoacidosis, bone fractures) and more recent concerns (lower limb amputation, Fournier's gangrene).

EXPERT OPINION

Overall, the safety profile of SGLT2is is good. The only increased adverse event that was consistently reported in clinical trials and observational studies is genital mycotic infections, with only a borderline increase in urinary tract infections. Among clinical trials, only the CANVAS program reported an unexpected increase in bone fractures and peripheral amputations. A variety of rare adverse events have been described as case reports, including ketoacidosis, amputations and Fournier gangrene, which led to specific warnings by regulatory agencies. Identifying predisposing patient's characteristics and/or precipitating clinical conditions would help prevent the most severe complications. These adverse events should not mask the overall cardiovascular and renal benefit of SGLT2is, especially in patients with type 2 diabetes at high cardiovascular risk.

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.

Relationship of patient background with macro- and microvascular complications: a 2-year post-marketing surveillance of vildagliptin in nearly 20,000 Japanese diabetic patients

BACKGROUND

Vildagliptin is indicated for type 2 diabetes mellitus (T2DM); however, the onset and exacerbation of diabetic complications in Japanese T2DM patients treated with vildagliptin is unknown.

RESEARCH DESIGN AND METHODS

This 2-year post-marketing surveillance (PMS) assessed the real-world safety and efficacy of vildagliptin therapy in 19,218 Japanese T2DM patients. The relationship between the incidence of macro- and microvascular complications with patient characteristics and changes in glycemic control (HbA1c) were evaluated.

RESULTS

The incidences of macro- and microvascular diseases were 1.14% and 3.09%, respectively. Patients with HbA1c ≥8.4% had a higher odds ratio (OR) for micro- and macrovascular disease (OR: 2.02 and 1.90) compared with patients with HbA1c <6.9%. Patient characteristics (OR, 95% CI) associated with macrovascular disease were age (1.04, 1.01-1.07) and a history of macrovascular disease (3.38, 1.98-5.75). Microvascular disease was associated with a final HbA1c level ≥7.0% (1.48, 1.11-1.98) and previous diabetic nephropathy (1.42, 1.05-1.93). The mean (SD) HbA1c decreased from 7.89% (1.46%) to 7.05% (0.99%) after 24 months.

CONCLUSIONS

Vildagliptin elicited no increases/exacerbations of diabetic complications; this PMS suggested that the incidence of diabetic complications tends to be low in subjects with good HbA1c control.

Diabetes pharmacotherapy and effects on the musculoskeletal system

Persons with type 1 or type 2 diabetes have a significantly higher fracture risk than age-matched persons without diabetes, attributed to disease-specific deficits in the microarchitecture and material properties of bone tissue. Therefore, independent effects of diabetes drugs on skeletal integrity are vitally important. Studies of incretin-based therapies have shown divergent effects of different agents on fracture risk, including detrimental, beneficial, and neutral effects. The sulfonylurea class of drugs, owing to its hypoglycemic potential, is thought to amplify the risk of fall-related fractures, particularly in the elderly. Other agents such as the biguanides may, in fact, be osteo-anabolic. In contrast, despite similarly expected anabolic properties of insulin, data suggests that insulin pharmacotherapy itself, particularly in type 2 diabetes, may be a risk factor for fracture, negatively associated with determinants of bone quality and bone strength. Finally, sodium-dependent glucose co-transporter 2 inhibitors have been associated with an increased risk of atypical fractures in select populations, and possibly with an increase in lower extremity amputation with specific SGLT2I drugs. The role of skeletal muscle, as a potential mediator and determinant of bone quality, is also a relevant area of exploration. Currently, data regarding the impact of glucose lowering medications on diabetes-related muscle atrophy is more limited, although preclinical studies suggest that various hypoglycemic agents may have either aggravating (sulfonylureas, glinides) or repairing (thiazolidinediones, biguanides, incretins) effects on skeletal muscle atrophy, thereby influencing bone quality. Hence, the therapeutic efficacy of each hypoglycemic agent must also be evaluated in light of its impact, alone or in combination, on musculoskeletal health, when determining an individualized treatment approach. Moreover, the effect of newer medications (potentially seeking expanded clinical indication into the pediatric age range) on the growing skeleton is largely unknown. Herein, we review the available literature regarding effects of diabetes pharmacotherapy, by drug class and/or by clinical indication, on the musculoskeletal health of persons with diabetes.

Pharmacology of dipeptidyl peptidase-4 inhibitors and its use in the management of metabolic syndrome: a comprehensive review on drug repositioning

OBJECTIVES

Despite advances in our understanding of metabolic syndrome (MetS) and the treatment of each of its components separately, currently there is no single therapy approved to manage it as a single condition. Since multi-drug treatment increases drug interactions, decreases patient compliance and increases health costs, it is important to introduce single therapies that improve all of the MetS components.

EVIDENCE ACQUISITION

We conducted a PubMed, Scopus, Google Scholar, Web of Science, US FDA, utdo.ir and clinicaltrial.gov search, gathered the most relevant preclinical and clinical studies that have been published since 2010, and discussed the beneficial effects of dipeptidyl peptidase (DPP)-4 inhibitors to prevent and treat different constituent of the MetS as a single therapy. Furthermore, the pharmacology of DPP-4 inhibitors, focusing on pharmacodynamics, pharmacokinetics, drug interactions and their side effects are also reviewed.

RESULTS

DPP-4 inhibitors or gliptins are a new class of oral anti-diabetic drugs that seem safe drugs with no severe side effects, commonly GI disturbance, infection and inflammatory bowel disease. They increase mass and function of pancreatic β-cells, and insulin sensitivity in liver, muscle and adipose tissue. It has been noted that gliptin therapy decreases dyslipidemia. DPP-4 inhibitors increase fatty oxidation, and cholesterol efflux, and decrease hepatic triglyceride synthase and de novo lipogenesis. They delay gastric emptying time and lead to satiety. Besides, gliptin therapy has anti-inflammatory and anti-atherogenic impacts, and improves endothelial function and reduces vascular stiffness.

CONCLUSION

The gathered data prove the efficacy of DPP-4 inhibitors in managing MetS in some levels beyond anti-diabetic effects. This review could be a lead for designing new DPP-4 inhibitors with greatest effects on MetS in future. Introducing drugs with polypharmacologic effects could increase the patient's compliance and decrease the health cost that there is not in multi-drug therapy. Graphical abstract ᅟ.

Identification of novel uracil derivatives incorporating benzoic acid moieties as highly potent Dipeptidyl Peptidase-IV inhibitors

Dipeptidyl Peptidase-IV (DPP-4) is a validated therapeutic target for type 2 diabetes. Aiming to interact with both residues Try629 and Lys554 in S₂' site, a series of novel uracil derivatives 1a-l and 2a-i incorporating benzoic acid moieties at the N₃ position were designed and evaluated for their DPP-4 inhibitory activity. Structure-activity relationships (SAR) study led to the identification of the optimal compound 2b as a potent and selective DPP-4 inhibitor (IC₅₀ = 1.7 nM). Docking study revealed the additional salt bridge formed between the carboxylic acid and primary amine of Lys554 has a key role in the enhancement of the activity. Furthermore, compound 2b exhibited no cytotoxicity in human hepatocyte LO2 cells up to 50 μM. Subsequent in vivo evaluations revealed that the ester of 2b robustly improves the glucose tolerance in normal mice. The overall results have shown that compound 2b has the potential to a safe and efficacious treatment for T2DM.

Clinical Use of DPP-4 Inhibitors

DPP-4 inhibitors were introduced for the treatment of type 2 diabetes in 2006. They stimulate insulin secretion and inhibit glucagon secretion by elevating endogenous GLP-1 concentrations without an intrinsic hypoglycaemia risk. Their efficacy potential to lower HbA1c is in the range between 0.5 and 1.0% and their safety profile is favorable. DPP-4 inhibitors are body weight neutral and they have demonstrated cardiovascular safety. Most compounds can be used in impaired renal function. Guidelines suggest the additional use of DPP-4 inhibitors after metformin failure in patients that do not require antidiabetic therapy with proven cardiovascular benefit. Recently, DPP-4 inhibitors have increasingly replaced sulfonylureas as second line therapy after metformin failure and many metformin/DPP-4 inhibitor fixed dose combinations are available. In later stages of type 2 diabetes, DPP-4 inhibitors are also recommended in the guidelines in triple therapies with metformin and SGLT-2 inhibitors or with metformin and insulin. A treatment with DPP-4 inhibitors should be stopped when GLP-1 receptor agonists are used. DPP-4 inhibitors can be used as monotherapy when metformin is contraindicated or not tolerated. Some studies have shown value of initial metformin-DPP-4 inhibitor combination therapy in special populations. This article gives an overview on the clinical use of DPP-4 inhibitors.

Physiology and Pharmacology of DPP-4 in Glucose Homeostasis and the Treatment of Type 2 Diabetes

Dipeptidyl peptidase-4 (DPP-4), also known as the T-cell antigen CD26, is a multi-functional protein which, besides its catalytic activity, also functions as a binding protein and a ligand for a variety of extracellular molecules. It is an integral membrane protein expressed on cells throughout the body, but is also shed from the membrane and circulates as a soluble protein in the plasma. A large number of bioactive molecules can be cleaved by DPP-4 in vitro, but only a few of these have been demonstrated to be physiological substrates. One of these is the incretin hormone, glucagon-like peptide-1 (GLP-1), which plays an important role in the maintenance of normal glucose homeostasis, and DPP-4 has been shown to be the key enzyme regulating its biological activity. This pathway has been targeted pharmacologically through the development of DPP-4 inhibitors, and these are now a successful class of anti-hyperglycaemic agents used to treat type 2 diabetes (T2DM). DPP-4 may additionally influence metabolic control via its proteolytic effect on other regulatory peptides, but it has also been reported to affect insulin sensitivity, potentially mediated through its non-enzymatic interactions with other membrane proteins. Given that altered expression and activity of DPP-4 are associated with increasing body mass index and hyperglycaemia, DPP-4 has been proposed to play a role in linking obesity and the pathogenesis of T2DM by functioning as a local mediator of inflammation and insulin resistance in adipose and hepatic tissue. As well as these broader systemic effects, it has also been suggested that DPP-4 may be able to modulate β-cell function as part of a paracrine system involving GLP-1 produced locally within the pancreatic islets. However, while it is evident that DPP-4 has the potential to influence glycaemic control, its overall significance for the normal physiological regulation of glucose homeostasis in humans and its role in the pathogenesis of metabolic disease remain to be established.

Alogliptin prevents diastolic dysfunction and preserves left ventricular mitochondrial function in diabetic rabbits

Background

There are increasing evidence that left ventricle diastolic dysfunction is the initial functional alteration in the diabetic myocardium. In this study, we hypothesized that alogliptin prevents diastolic dysfunction and preserves left ventricular mitochondrial function and structure in diabetic rabbits.

Methods

A total of 30 rabbits were randomized into control group (CON, n = 10), alloxan-induced diabetic group (DM, n = 10) and alogliptin-treated (12.5 mg/kd/day for 12 weeks) diabetic group (DM-A, n = 10). Echocardiographic and hemodynamic studies were performed in vivo. Mitochondrial morphology, respiratory function, membrane potential and reactive oxygen species (ROS) generation rate of left ventricular tissue were assessed. The serum concentrations of glucagon-like peptide-1, insulin, inflammatory and oxidative stress markers were measured. Protein expression of TGF-β1, NF-κB p65 and mitochondrial biogenesis related proteins were determined by Western blotting.

Results

DM rabbits exhibited left ventricular hypertrophy, left atrial dilation, increased E/e′ ratio and normal left ventricular ejection fraction. Elevated left ventricular end diastolic pressure combined with decreased maximal decreasing rate of left intraventricular pressure (− dp/dtmax) were observed. Alogliptin alleviated ventricular hypertrophy, interstitial fibrosis and diastolic dysfunction in diabetic rabbits. These changes were associated with decreased mitochondrial ROS production rate, prevented mitochondrial membrane depolarization and improved mitochondrial swelling. It also improved mitochondrial biogenesis by PGC-1α/NRF1/Tfam signaling pathway.

Conclusions

The DPP-4 inhibitor alogliptin prevents cardiac diastolic dysfunction by inhibiting ventricular remodeling, explicable by improved mitochondrial function and increased mitochondrial biogenesis.

Efficacy of anagliptin as compared to linagliptin on metabolic parameters over 2 years of drug consumption: A retrospective cohort study

AIM

To evaluate the comparative effectiveness of anagliptin and linagliptin on the clinical parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

A 2-year retrospective cohort study was conducted in patients with T2DM who received anagliptin and linagliptin. We enrolled 234 patients (anagliptin group, 117 patients; linagliptin group, 117 patients).

RESULTS

The glycemic control considerably improved 3, 6, 12, and 24 mo after the administration of both dipeptidyl peptidase-4 (DPP-4) inhibitors. Following the administration of anagliptin, the diastolic blood pressure and serum total cholesterol levels decreased. However, serum high-density lipoprotein cholesterol levels increased and urinary albumin-creatinine ratio decreased following linagliptin administration. Furthermore, the liver function improved after the administration of linagliptin.

CONCLUSION

These findings suggest that that the efficacy of DPP-4 inhibitors on the blood pressure, lipid profile, and liver function differs between anagliptin and linagliptin.

Pharmacotherapy of type 2 diabetes in patients with chronic liver disease: focus on nonalcoholic fatty liver disease

INTRODUCTION

Pharmacotherapy used to treat type 2 diabetes mellitus (T2DM) is facing a paradigm shift in clinical practice with recent cardiovascular (CV) outcome trials having a substantial impact on drug prescription with treatment having a more tailored approach. In patients with T2DM, the issue of chronic liver disease is multifaceted. However, a clinical evidence is emerging on the beneficial effect of antidiabetic medications on nonalcoholic fatty liver disease (NAFLD).

AREAS COVERED

The authors provide a synopsis on the current and upcoming pharmacotherapy for NAFLD, including the challenges with their development, focusing on drugs for T2DM. Clinical data on the potential benefits and safety issues are assessed with the aim of proposing an individualized algorithm for patient management. Both MEDLINE and ClinicalTrials.Gov are used to derive the relevant information.

EXPERT OPINION

Considering the pivotal role of insulin resistance in NAFLD, insulin sensitizers should be the treatment of choice. Accordingly, pioglitazone is the only drug with a significant effect on liver fibrosis, the driver of disease progression and long-term outcome. Among new glucose-lowering drugs, glucagon-like-peptide 1 receptor agonists or sodium-glucose cotransporter type 2 inhibitors have shown positive effects in phase II studies and are qualifying as potential candidates for NAFLD treatment in diabetes.

Adverse Drug Events Associated with sitagliptin Versus canagliflozin for the Treatment of Patients with Type 2 Diabetes Mellitus: A Systematic Comparison Through a Meta-Analysis

INTRODUCTION

In this meta-analysis, we aimed to systematically compare the adverse drug events associated with sitagliptin (100 mg) versus canagliflozin 100 or 300 mg in patients who were treated for type 2 diabetes mellitus (T2DM).

METHODS

Online databases were searched for relevant studies comparing sitagliptin (100 mg) versus canagliflozin. Adverse drug events were considered as the clinical endpoints. The analysis was carried out by RevMan software whereby risk ratios (RR) and 95% confidence intervals (CI) were generated.

RESULTS

Five studies with a total number of 2322 patients were included. When sitagliptin (100 mg) was compared with canagliflozin (100 mg), the endpoints of any adverse events, adverse events leading to drug discontinuation, serious adverse events, urinary tract infections, hypoglycemia, and adverse events related to hypovolemia were not significantly different: (RR 1.10, 95% CI 1.00-1.21; P = 0.05), (RR 1.20, 95% CI 0.67-2.16; P = 0.54), (RR 0.90, 95% CI 0.49-1.66; P = 0.73), (RR 1.26, 95% CI 0.77-2.08; P = 0.36), (RR 1.01, 95% CI 0.30-3.43; P = 0.99), and (RR 1.76, 95% CI 0.52-5.94; P = 0.36), respectively. However, canagliflozin was associated with increased genital mycotic infection (RR 4.32, 95% CI 2.11-8.83; P = 0.0001). When genital mycotic infections associated with sitagliptin versus canagliflozin were compared in male and female patients separately, the risk was still significantly higher with canagliflozin: (RR 7.00, 95% CI 2.44-20.06; P = 0.003) and (RR 4.02, 95% CI 2.22-7.27; P = 0.00001), respectively. The same results were obtained when sitagliptin (100 mg) was compared to canagliflozin 300 mg.

CONCLUSIONS

Canagliflozin was associated with a significantly higher risk of genital mycotic infections when compared to sitagliptin. However, the other adverse drug events were similarly manifested when sitagliptin 100 mg was compared to either canagliflozin 100 or 300 mg.

Cardiovascular safety of DPP-4 inhibitors compared with sulphonylureas: Results of randomized controlled trials and observational studies

After failure of metformin monotherapy, another glucose-lowering agent should be added to improve glucose control. The clinician has several pharmacological choices, including the addition of a sulphonylurea (SU) or a dipeptidyl peptidase-4 inhibitor (DPP-4i). While the cardiovascular safety of SUs remains a matter of controversy, DPP-4is have proven their non-inferiority vs placebo in recent cardiovascular (CV) outcome trials. In the absence of a head-to-head CV outcome trial-the CAROLINA, comparing linagliptin with glimepiride, is still ongoing-only indirect information can be found in the literature to compare CV outcomes (major CV events, myocardial infarction, ischaemic stroke, CV death and all-cause mortality) in patients with type 2 diabetes mellitus (T2DM) treated with SUs or DPP-4is. Thus, this comprehensive review summarizes the CV outcomes (excluding heart failure) reported in meta-analyses of randomized controlled trials (RCTs) of SUs vs placebo or other glucose-lowering agents, DPP-4is vs placebo or other glucose-lowering agents and SUs vs DPP-4is in phase-II/III studies. Also, the results of observational studies reporting CV events in patients treated with either SUs or DPP-4is have been carefully examined. Overall, the CV safety of SUs appears to be poorer than that of DPP-4is in both RCTs and cohort studies. However, the results are somewhat disparate, and such heterogeneity may be explained by different patient characteristics across studies, but also perhaps by differences between various molecules in each pharmacological class. In particular, some doubt about a class effect affecting SU CV safety has been raised. The results of CAROLINA are expected to shed more light on SU CV concerns, especially compared with DPP-4is.

Pharmacovigilance Evaluation of the Association Between DPP-4 Inhibitors and Heart Failure: Stimulated Reporting and Moderation by Drug Interactions

INTRODUCTION

In the SAVOR-TIMI trial, the risk of heart failure (HF) was increased by 27% in T2D patients randomized to the dipeptidyl peptidase-4 inhibitor (DPP4i) saxagliptin. Other studies have provided inconsistent results regarding this association. Herein, we performed a pharmacovigilance analysis of the rate of HF associated with DPP4is, focusing on stimulated reporting and moderation by drug-drug interactions.

METHODS

We mined the FDA adverse event (AE) reporting system (FAERS) from 2004q1 to 2017q3, including a total of 9906,642 AE reports. Rates (/1000 reports) of HF within the reports for DPP4is and reports for other antidiabetic drugs were calculated for the period up to 2013q3 (date of publication of the SAVOR-TIMI trial results) and from 2013q4 to 2017q3. Analyses were refined by filtering according to therapeutic area, concomitant diseases and drugs, and competing AEs.

RESULTS

The rate of HF among the AE reports filed for DPP4is significantly increased after 2013q3, especially for saxagliptin. When compared to non-insulin non-glitazone antidiabetic drugs, the proportional reporting ratio (PRR) of HF for DPP4is was 0.62 (95% CI 0.56-0.68) up to 2013q3 and 2.12 (95% CI 1.96-2.28) from 2013q4 to 2017q3. This stimulated reporting was consistent in subanalyses based on the presence/absence of cardiac disorders and after controlling for competing AEs. The rate of HF among AE reports for DPP4is was modestly moderated by the concomitant use of metformin (- 15%) and strongly moderated by the concomitant use of SGLT2 inhibitors (- 63%), even after excluding competing AEs.

CONCLUSIONS

Within the FAERS, the association between HF and DPP4is was biased by stimulated reporting, implying that the publication of the SAVOR-TIMI trial and the subsequent regulatory warnings primed clinicians to report HF events in DPP4i users as drug-related AEs. The rate of HF associated with DPP4is was moderated when they were used in combination with SGLT2 inhibitors.