Reduction in cardiovascular and all-cause mortality in the EMPA-REG OUTCOME trial: A critical analysis

Type 2 diabetes in children and adolescents: distinct characteristics and evidence-based management

PURPOSE

Since the dramatic rise of obesity prevalence in childhood and adolescence has contributed to increased rates of type 2 diabetes (T2D) in youth, we sought to explore current evidence-based management options for pediatric T2D patients.

METHODS

A comprehensive literature search was performed for studies of T2D in childhood and adolescence until September 2021.

RESULTS

Special pathophysiological and diagnostic characteristics of T2D in this age are presented, while the main focus of the article is on management. Lifestyle interventions with healthy diet and exercise are of great importance for the treatment of T2D in children and adolescents. Metformin and insulin remain the traditional therapeutical means, while liraglutide recently gained indication for children older than 10 years both in USA and Europe. Data on the use, efficacy, safety and therapeutic considerations of other pharmacological treatments in children and adolescents with T2D are critically discussed.

CONCLUSION

Although many new and promising therapeutic strategies have been introduced during recent years for the management of T2D in adults, available therapeutic options for the management of pediatric T2D remain limited.

Counteracting heart failure with diabetes drugs: a review into the pharmacokinetic and pharmacodynamic properties

INTRODUCTION

: Heart failure (HF) is becoming a huge public health burden. New diabetes drugs for type 2 diabetes (T2D), sodium-glucose cotransporter type 2 inhibitors (SGLT2is), reduce the rate of hospitalization for HF in placebo-controlled trials.

AREAS COVERED

: Pharmacokinetics of dapagliflozin and empagliflozin (in presence of renal impairment and hepatic dysfunction, two comorbidities frequently associated with HF) and pharmacodynamic studies in patients with HF. Main HF outcomes in T2D patients with cardiovascular risk and in patients with reduced (HFrEF) or preserved (HFpEF) ejection fraction, with or without T2D, from DAPA-HF, EMPEROR-Reduced and EMPEROR-Preserved original findings and post hoc analyses.

EXPERT OPINION

: No clinically relevant changes are expected concerning SGLT2i pharmacokinetics in patients with HF while pharmacodynamic studies reported improvements in myocardium/vascular parameters, biomarkers and functional status. All SGLT2is showed a remarkable reduction in hospitalization for HF in patients with T2D and high cardiovascular risk. Furthermore, both dapagliflozin and empagliflozin improved the prognosis of patients with HFrEF, independently of the presence of T2D. Similar results were reported with empagliflozin in patients with HFpEF, to be confirmed with dapagliflozin in an ongoing trial (DELIVER). Thus, SGLT2is offer a new opportunity for the prevention and management of HF in patients with or without T2D.

Sodium-glucose cotransporter type 2 inhibitors for the treatment of type 2 diabetes mellitus

The management of type 2 diabetes mellitus (T2DM) is becoming increasingly complex. Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are the newest antidiabetic agents for T2DM. By targeting the kidney, they have a unique mechanism of action, which results in enhanced glucosuria, osmotic diuresis and natriuresis, thereby improving glucose control with a limited risk of hypoglycaemia and exerting additional positive effects such as weight loss and the lowering of blood pressure. Several outcome studies with canagliflozin, dapagliflozin or empagliflozin reported a statistically significant reduction in major cardiovascular events, hospitalization for heart failure and progression to advanced renal disease in patients with T2DM who have established atherosclerotic cardiovascular disease, several cardiovascular risk factors, albuminuric mild to moderate chronic kidney disease or heart failure. Current guidelines proposed a new paradigm in the management of T2DM, with a preferential place for SGLT2is, after metformin, in patients with atherosclerotic cardiovascular disease, heart failure and progressive kidney disease. Ongoing trials might extend the therapeutic potential of SGLT2is in patients with, but also without, T2DM. This Review provides an update of the current knowledge on SGLT2is, moving from their use as glucose-lowering medications to their new positioning as cardiovascular and renal protective agents.

Inflammatory Targets in Diabetic Nephropathy

One of the most frequent complications in patients with diabetes mellitus is diabetic nephropathy (DN). At present, it constitutes the first cause of end stage renal disease, and the main cause of cardiovascular morbidity and mortality in these patients. Therefore, it is clear that new strategies are required to delay the development and the progression of this pathology. This new approach should look beyond the control of traditional risk factors such as hyperglycemia and hypertension. Currently, inflammation has been recognized as one of the underlying processes involved in the development and progression of kidney disease in the diabetic population. Understanding the cascade of signals and mechanisms that trigger this maladaptive immune response, which eventually leads to the development of DN, is crucial. This knowledge will allow the identification of new targets and facilitate the design of innovative therapeutic strategies. In this review, we focus on the pathogenesis of proinflammatory molecules and mechanisms related to the development and progression of DN, and discuss the potential utility of new strategies based on agents that target inflammation.

Effects of glucose-lowering agents on surrogate endpoints and hard clinical renal outcomes in patients with type 2 diabetes

Diabetic kidney disease (DKD) represents an enormous burden in patients with type 2 diabetes mellitus (T2DM). Preclinical studies using most glucose-lowering agents have suggested renal-protective effects, but the proposed mechanisms of renoprotection have yet to be defined, and the promising results from experimental studies remain to be translated into human clinical findings to improve the prognosis of patients at risk of DKD. Also, it is important to distinguish effects on surrogate endpoints, such as decreases in albuminuria and estimated glomerular filtration rate (eGFR), and hard clinical endpoints, such as progression to end-stage renal disease (ESRD) and death from renal causes. Data regarding insulin therapy are surprisingly scarce, and it is nearly impossible to separate the effects of better glucose control from those of insulin per se, whereas favourable preclinical data with metformin, thiazolidinediones and dipeptidyl peptidase (DPP)-4 inhibitors are plentiful, and positive effects have been observed in clinical studies, at least for surrogate endpoints. The most favourable renal results have been reported with glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter type-2 inhibitors (SGLT2is). Significant reductions in both albuminuria and eGFR decline have been reported with these classes of glucose-lowering medications compared with placebo and other glucose-lowering agents. Moreover, in large prospective cardiovascular outcome trials using composite renal outcomes as secondary endpoints, both GLP-1RAs and SGLT2is added to standard care reduced renal outcomes combining persistent macro-albuminuria, doubling of serum creatinine, progression to ESRD and kidney-related death; however, to date, only SGLT2is have been clearly shown to reduce such hard clinical outcomes. Yet, as the renoprotective effects of SGLT2is and GLP-1RAs appear to be independent of glucose-lowering activity, the underlying mechanisms are still a matter of debate. For this reason, further studies with renal outcomes as primary endpoints are now awaited in T2DM patients at high risk of DKD, including trials evaluating the potential add-on benefits of combined GLP-1RA-SGLT2i therapies.

Effects of SGLT2 inhibitors on systemic and tissue low-grade inflammation: The potential contribution to diabetes complications and cardiovascular disease

Chronic low-grade inflammation is a recognized key feature associated with type 2 diabetes mellitus (T2DM) and its complications. In prospective randomized trials, sodium-glucose cotransporter type 2 (SGLT2) inhibitors have demonstrated benefits related to several cardiovascular and renal risk factors, including HbA_1c, blood pressure, body weight, renal hyperfiltration, and improvement of cardiorenal outcomes. SGLT2 inhibitors may improve adipose tissue function and induce decreases in serum leptin, TNF-α and IL-6 while increasing adiponectin. While data on high-sensitivity C-reactive protein and other inflammatory markers are relatively scarce in humans, in animals, a number of reports have shown reductions in cytokine and chemokine concentrations in parallel with protective effects against progression of atherosclerotic lesions. Experimental findings also suggest that part of the renoprotective effects of SGLT2 inhibition may be related to anti-inflammatory actions at the kidney level. Underlying mechanisms to explain this anti-inflammatory effect are multiple, but may involve weight loss, and reduction in adipose tissue inflammation, slight increase in ketone bodies and diminution of uric acid levels or attenuation of oxidative stress. However, further studies in diabetes patients with specific assessment of inflammatory markers are still necessary to determine the specific contribution of the anti-inflammatory action of SGLT2 inhibitors to the reduction of cardiovascular and renal complications and mortality observed with this class of antidiabetic drugs.

Cardiovascular outcome studies in type 2 diabetes: Comparison between SGLT2 inhibitors and GLP-1 receptor agonists

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) are two pharmacological classes that have proven their efficacy to reduce major cardiovascular events (MACEs) in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease in large prospective cardiovascular outcome trials (CVOTs): EMPA-REG OUTCOME (empagliflozin), CANVAS (canagliflozin), LEADER (liraglutide) and SUSTAIN 6 (semaglutide). Some heterogeneity appears to exist between the various agents within the two pharmacological classes. Whether these positive results could be extrapolated to patients without cardiovascular disease is still unknown. The underlying mechanisms remain a matter of debate but appear to differ between SGLT2is and GLP-1RAs. One crucial question is which patient's characteristics should be taken into account to guide the choice between a SGLT2i or a GLP-1RA according to a personalized approach. Heart failure should encourage the use of a SGLT2i whereas moderate to severe chronic kidney disease should favour the prescription of a GLP-1RA. Despite the results of recent CVOTs, numerous patients who are good candidates for benefiting of these agents do not receive them in clinical practice. Currently, there is a paradigm shift in T2DM management, moving from a primary objective of glucose control to a cardiovascular and renal protection.

The safety of empagliflozin plus metformin for the treatment of type 2 diabetes

INTRODUCTION

Metformin is the first-line glucose-lowering medication in type 2 diabetes mellitus (T2DM), but it generally requires soon or later the addition of a second-line therapy, among which a sodium-glucose cotransporter type 2 (SGLT-2) inhibitor, to reach and maintain adequate glucose control. Areas covered: This narrative review provides an analysis of both efficacy and safety of a dual therapy combining metformin and empagliflozin, a SGLT-2 inhibitor that has proven its' potential to reduce major cardiovascular (CV) events, mortality, and renal outcomes in patients with T2DM and established CV disease. Pharmacokinetic studies showed the absence of drug-drug interactions and demonstrate bioequivalence between fixed-dose combination (FDC) and individual tablets of empagliflozin and metformin. Focus will be put on the use of this dual therapy in special populations. Expert opinion: The addition of empagliflozin to metformin therapy improves glucose control, with a minimal risk of hypoglycemia, while reducing body weight and arterial blood pressure. EMPA-REG OUTCOME showed that this combined therapy may be used in patients with established CV disease or heart failure. However, caution may be required in fragile elderly patients and in patients with severe impaired renal function. Further post-marketing surveillance is recommended to demonstrate long-term safety. FDC may improve adherence.

After the LEADER trial and SUSTAIN-6, how do we explain the cardiovascular benefits of some GLP-1 receptor agonists?

Recent cardiovascular outcome trials - the LEADER with liragutide and SUSTAIN-6 with semaglutide - have shown significant reductions of major cardiovascular (CV) events with these glucagon-like peptide (GLP)-1 receptor agonists. Progressive separation of the treatment and placebo curves, starting clearly between 12 and 18 months of the trial period, and significant reductions in the risk of myocardial infarction and stroke, indicate that the beneficial CV effects observed with GLP-1 receptor agonists could be due to an antiatherogenic effect. So far, the reasons for such an effect of GLP-1 receptor agonists have not been entirely clear, although several hypotheses may be proposed. As the reductions in glycated haemoglobin and systolic blood pressure (SBP) in these trials were modest, and both trials lasted only a short period of time, reductions in hyperglycaemia and SBP are unlikely to be involved in the beneficial CV effects of GLP-1 receptor agonists. On the other hand, their effect on lipids and, in particular, the dramatic decrease in postprandial hypertriglyceridaemia may explain their beneficial CV actions. Reduction of body weight, including a significant decrease in visceral fat in patients using GLP-1 receptor agonists, may also have beneficial CV effects by reducing chronic proatherogenic inflammation. In addition, there are in-vitro data showing a direct anti-inflammatory effect with these agents that could also be involved in their beneficial CV effects. Moreover, studies in humans have shown significant beneficial effects on ischaemic myocardium after a very short treatment period, suggesting a direct effect of GLP-1 receptor agonists on myocardium, although the precise mechanism remains unclear. Finally, as a reduction in insulin resistance has been associated with a decrease in CV risk, it cannot be ruled out that the lowering of insulin resistance induced by GLP-1 receptor agonists might also be involved in their beneficial CV actions.

GLP-1 receptor agonists and heart failure in diabetes

The prevalence of heart failure (HF) is increasing in patients with type 2 diabetes (T2D), and glucose-lowering agents have distinctive effects on the risk of developing HF that requires hospitalization. Such an increased risk has been consistently reported with thiazolidinediones (glitazones) and perhaps also with the dipeptidyl peptidase (DPP)-4 inhibitor saxagliptin (at least in SAVOR - TIMI 53), whereas a markedly decreased risk was highlighted with the sodium - glucose cotransporter type 2 (SGLT2) inhibitor empagliflozin in EMPA-REG OUTCOME. Yet, the effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on myocardial function remain controversial. Whereas some promising observations have been reported in various animal models, the effects of GLP-1RAs on myocardial function in humans are more heterogeneous, while the positive effect on left ventricular ejection fraction (LVEF), if any, appears to be inconsistent and rather modest in most patients with HF. However, no increased risk of hospitalization for HF has been reported with GLP-1RAs in meta-analyses of phase-II/III trials (exenatide, albiglutide, dulaglutide, liraglutide), demonstrating the safety of this pharmacological class, and such findings have been confirmed by three large prospective cardiovascular outcome trials (ELIXA with lixisenatide, LEADER with liraglutide and SUSTAIN-6 with semaglutide). In particular, LEADER reported a trend towards a reduction in HF hospitalization (-13%, P = 0.14), together with a significant reduction in cardiovascular and all-cause mortality in patients with T2D at risk of cardiovascular disease. These results are reassuring in the face of the somewhat negative results of the FIGHT trial, which evaluated the effects of liraglutide in patients with advanced HF and low LVEF, such that further studies and caution are now required when using this agent to treat such patients in clinical practice.

Cardiovascular Effects of New Oral Glucose-Lowering Agents: DPP-4 and SGLT-2 Inhibitors

Cardiovascular disease (CVD) is a major challenge in the management of type 2 diabetes mellitus. Glucose-lowering agents that reduce the risk of major cardiovascular events would be considered a major advance, as recently reported with liraglutide and semaglutide, 2 glucagon-like peptide-1 receptor agonists, and with empagliflozin and canagliflozin, 2 SGLT-2 (sodium-glucose cotransporter type 2) inhibitors, but not with DPP-4 (dipeptidyl peptidase-4) inhibitors. The present review is devoted to CV effects of new oral glucose-lowering agents. DPP-4 inhibitors (gliptins) showed some positive cardiac and vascular effects in preliminary studies, and initial data from phase 2 to 3 clinical trials suggested a reduction in major cardiovascular events. However, subsequent CV outcome trials with alogliptin, saxagliptin, and sitagliptin showed noninferiority but failed to demonstrate any superiority compared with placebo in patients with type 2 diabetes mellitus and high CV risk. An unexpected higher risk of hospitalization for heart failure was reported with saxagliptin. SGLT-2 inhibitors (gliflozins) promote glucosuria, thus reducing glucose toxicity and body weight, and enhance natriuresis, thus lowering blood pressure. Two CV outcome trials in type 2 diabetes mellitus patients mainly in secondary prevention showed remarkable positive results. Empagliflozin in EMPA-REG-OUTCOME (EMPAgliflozin Cardiovascular OUTCOME Events in Type 2 Diabetes Mellitus Patients) reduced major cardiovascular events, CV mortality, all-cause mortality, and hospitalization for heart failure. In CANVAS (Canagliflozin Cardiovascular Assessment Study), the reduction in CV mortality with canagliflozin failed to reach statistical significance despite a similar reduction in major cardiovascular events. The underlying protective mechanisms of SGLT-2 inhibitors remain unknown and both hemodynamic and metabolic explanations have been proposed. CVD-REAL studies (Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors; with the limitation of an observational approach) suggested that these favorable results may be considered as a class effect shared by all SGLT-2 inhibitors (including dapagliflozin) and be extrapolated to a larger population of patients with type 2 diabetes mellitus in primary prevention. Ongoing CV outcome trials with other DPP-4 (linagliptin) and SGLT-2 (dapagliflozin, ertugliflozin) inhibitors should provide additional information about CV effects of both pharmacological classes.

Pharmacokinetic Characteristics and Clinical Efficacy of an SGLT2 Inhibitor Plus DPP-4 Inhibitor Combination Therapy in Type 2 Diabetes

Type 2 diabetes (T2D) generally requires a combination of several pharmacological approaches to control hyperglycaemia. Combining a sodium-glucose cotransporter type 2 inhibitor (SGLT2I, also known as gliflozin) and a dipeptidyl peptidase-4 inhibitor (DPP-4I, also known as gliptin) appears to be an attractive strategy because of complementary modes of action. This narrative review analyzes the pharmacokinetics and clinical efficacy of different combined therapies with an SGLT2I (canagliflozin, dapagliflozin, empagliflozin, ertugliflozin, ipragliflozin, luseogliflozin, tofogliflozin) and DPP-4I (linagliptin, saxagliptin, sitagliptin, teneligliptin). Drug-drug pharmacokinetic interaction studies do not show any significant changes in peak concentrations (C _max) and total exposure (area under the curve of plasma concentrations [AUC]) of either drug when they were administered together orally compared with corresponding values when each of them was absorbed alone. Two fixed-dose combinations (FDCs) are already available (dapagliflozin-saxagliptin, empagliflozin-linagliptin) and others are in development (ertugliflozin-sitagliptin). Preliminary results show bioequivalence of the two medications administered as FDC tablets when compared with coadministration of the individual tablets. Dual therapy is more potent than either monotherapy in patients treated with diet and exercise or already treated with metformin. SGLT2I and DPP-4I could be used as initial combination or in a stepwise approach. The additional glucose-lowering effect appears to be more marked when a gliflozin is added to a gliptin than when a gliptin is added to a gliflozin. Combining the two pharmacological options is safe and does not induce hypoglycaemia.

Mortality Reduction in EMPA-REG OUTCOME Trial: Beyond the Antidiabetes Effect

Two recent large-scale cardiovascular outcome trials, a now common tool in assessing the safety of pharmacological treatments for type 2 diabetes, reported significant reductions in all-cause mortality. In EMPA-REG OUTCOME [BI 10773 (Empagliflozin) Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients], patients who received the SGLT2 inhibitor empagliflozin had a notable reduction of 9.2 deaths per 1,000 per year, while LEADER (Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results-A Long Term Evaluation) found that the patients receiving the GLP-1 receptor agonist liraglutide had a reduction of 3.7 deaths per 1,000 per year. The hypotheses to explain the sizable mortality reduction in EMPA-REG OUTCOME have mainly focused on the potential cardiovascular mechanisms of empagliflozin, but none considered its expected antidiabetes effects. I estimated the portion of the reduction in mortality observed in EMPA-REG OUTCOME expected to be a result of its antidiabetes effects, as measured by glycemic control and the need for additional antidiabetes medication, and contrasted it with LEADER. With use of the mean 0.45% reduction in HbA_1c with empagliflozin compared with placebo in EMPA-REG OUTCOME, the rate reduction of 9.2 deaths per 1,000 per year would be expected to be at most 4.5 deaths per 1,000 per year, leaving 4.7 deaths per 1,000 per year otherwise explained. On the other hand, LEADER's rate reduction of 3.7 deaths per 1,000 per year with liraglutide would be expected to be 3.5 by virtue of its effect on HbA_1c, leaving 0.2 deaths per 1,000 per year explained otherwise. Similar results were found using the need for additional antidiabetes treatment during follow-up to measure the antidiabetes impact. In conclusion, the expected antidiabetes effects of empagliflozin and liraglutide on the reduction in mortality are important. However, empagliflozin appears to have significant additional effects on survival, possibly due to specific cardiovascular mechanisms, which merit further investigation.

Cardiovascular effects of sodium glucose cotransporter 2 inhibitors

As the first cardiovascular (CV) outcome trial of a glucose-lowering agent to demonstrate a reduction in the risk of CV events in patients with type 2 diabetes mellitus (T2DM), the EMPAgliflozin Removal of Excess Glucose: Cardiovascular OUTCOME Event Trial in Type 2 Diabetes Mellitus Patients (EMPA-REG OUTCOME^®) trial, which investigated the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin, has generated great interest among health care professionals. CV outcomes data for another SGLT2 inhibitor, canagliflozin, have been published recently in the CANagliflozin CardioVascular Assessment Study (CANVAS) Program, as have CV data from the retrospective real-world study Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors (CVD-REAL), which compared SGLT2 inhibitors with other classes of glucose-lowering drugs. This review discusses the results of these three studies and, with a focus on EMPA-REG OUTCOME, examines the possible mechanisms by which SGLT2 inhibitors may reduce CV risk in patients with T2DM.

Dapagliflozin and saxagliptin tablets for adults with type 2 diabetes

INTRODUCTION

Saxagliptin (a dipeptidyl peptidase-4 inhibitor, DPP-4i) and dapagliflozin (a sodium-glucose cotransporter type 2 inhibitor, SGLT2i) improve glucose control in type 2 diabetes (T2D) through different potentially complementary mechanisms, thus offering the opportunity for a combined therapy. Area covered: The characteristics of the saxagliptin/dapagliflozin combination are analysed, focusing on: 1) pharmacokinetic and pharmacodynamic properties; 2) efficacy and safety in phase III trials with concurrent and sequential add-on therapy; and 3) potential use in clinical practice, including in special populations (cardiovascular disease, heart failure, chronic kidney disease, elderly). Expert commentary: Conclusions drawn from clinical trials investigating combination with the separate drugs are considered to apply to the fixed-dose combination (FDC) that demonstrates bioequivalence. Dual saxagliptin/dapagliflozin therapy is more potent than either monotherapy and can be used as an initial combination or a stepwise sequential approach. Dual therapy is generally well tolerated and may be used in special populations, with some limitations because of the presence of dapagliflozin. However, the latter may offer some advantages because of multiple effects attributed to SGLT2i. The best place of this dual combination for the management of T2D and the profile of patients who will make the most of this combined therapy remains to be defined.

Pharmacological management of type 2 diabetes: what's new in 2017?

INTRODUCTION

Novelties in the management of type 2 diabetes are dominated by the commercialisation of new glucose-lowering agents, which offer alternatives to older antidiabetic medications, and by the publication of several prospective placebo-controlled outcome trials, which demonstrated not only cardiovascular safety but also cardiovascular and renal protection with some new medications. Areas covered: Updates regarding the use of glucose-lowering agents are discussed from a clinical point of view. Some new viewpoints concern older antidiabetic agents such as metformin, sulfonylureas and glitazones whose benefit-risk balance has been revisited, especially in high risk patients. The recent data regarding DPP-4 inhibitors (gliptins) focused on the safety profile of this pharmacological class, including in patients with impaired renal function. The highlight concerns the cardiovascular (and renal) protection by some GLP-1 receptor agonists (liraglutide, semaglutide) and SGLT2 inhibitors (empagliflozin, canagliflozin) in patients with high cardiovascular risk. Finally, efficacy and safety of new combinations and advances in insulin therapy will be briefly discussed. Expert commentary: The recent data from randomized controlled trials, meta-analyses and observational real-life studies should trigger a revision of the algorithm for the treatment of hyperglycemia in type 2 diabetes, especially in patients with high cardiovascular and/or renal risk.

Cardiovascular Protection by Sodium Glucose Cotransporter 2 Inhibitors: Potential Mechanisms

The mechanism of action of empagliflozin in reducing the risk of adverse cardiovascular outcomes vs placebo in patients with type 2 diabetes mellitus and a high risk of cardiovascular disease in the Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME) trial is currently unknown. An antiatherosclerotic effect is considered unlikely given the speed of the observed decrease in cardiovascular mortality. Hemodynamic effects, such as reductions in blood pressure and intravascular volume, and involving osmotic diuresis, may provide a more plausible explanation. Metabolic effects, such as cardiac fuel energetics, and hormonal effects, such as increased glucagon release, may also contribute to the results observed during EMPA-REG OUTCOME. This review discusses the main hypotheses suggested to date.

Dapagliflozin suppresses glucagon signaling in rodent models of diabetes

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of antidiabetic drug used for the treatment of diabetes. These drugs are thought to lower blood glucose by blocking reabsorption of glucose by SGLT2 in the proximal convoluted tubules of the kidney. To investigate the effect of inhibiting SGLT2 on pancreatic hormones, we treated perfused pancreata from rats with chemically induced diabetes with dapagliflozin and measured the response of glucagon secretion by alpha cells in response to elevated glucose. In these type 1 diabetic rats, glucose stimulated glucagon secretion by alpha cells; this was prevented by dapagliflozin. Two models of type 2 diabetes, severely diabetic Zucker rats and db/db mice fed dapagliflozin, showed significant improvement of blood glucose levels and glucose disposal, with reduced evidence of glucagon signaling in the liver, as exemplified by reduced phosphorylation of hepatic cAMP-responsive element binding protein, reduced expression of phosphoenolpyruvate carboxykinase 2, increased hepatic glycogen, and reduced hepatic glucose production. Plasma glucagon levels did not change significantly. However, dapagliflozin treatment reduced the expression of the liver glucagon receptor. Dapagliflozin in rodents appears to lower blood glucose levels in part by suppressing hepatic glucagon signaling through down-regulation of the hepatic glucagon receptor.

Cardiovascular Protection by Sodium Glucose Cotransporter 2 Inhibitors: Potential Mechanisms

The mechanism of action of empagliflozin in reducing the risk of adverse cardiovascular outcomes vs placebo in patients with type 2 diabetes mellitus and a high risk of cardiovascular disease in the Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME) trial is currently unknown. An antiatherosclerotic effect is considered unlikely given the speed of the observed decrease in cardiovascular mortality. Hemodynamic effects, such as reductions in blood pressure and intravascular volume, and involving osmotic diuresis, may provide a more plausible explanation. Metabolic effects, such as cardiac fuel energetics, and hormonal effects, such as increased glucagon release, may also contribute to the results observed during EMPA-REG OUTCOME. This review discusses the main hypotheses suggested to date.

Impact of glucose-lowering therapies on risk of stroke in type 2 diabetes

Patients with type 2 diabetes (T2D) have an increased risk of stroke compared with people without diabetes. However, the effects of glucose-lowering drugs on risk of ischaemic stroke in T2D have been less extensively investigated than in coronary heart disease. Some evidence, including the UKPDS, has suggested a reduced risk of stroke with metformin, although the number of studies is limited. Inhibition of the K_ATP channels increases ischaemic brain lesions in animals. This is in agreement with a recent meta-analysis showing an increased risk of stroke with sulphonylureas vs. various comparators as both mono- and combination therapy. Pioglitazone can prevent recurrence of stroke in patients with previous stroke, as already shown in PROactive, although results are less clear for first strokes. As for DPP-4 inhibitors, there was a non-significant trend towards benefit for stroke, whereas a possible increased risk of stroke with SGLT2 inhibitors-and in particular, empagliflozin in the EMPA-REG OUTCOME trial-has been suggested and requires clarification. Experimental results support a potential protective effect of GLP-1 receptor agonists against stroke that has, at least in part, been translated to clinical benefits in T2D patients in the LEADER and SUSTAIN-6 trials. Further interventional studies are now warranted to confirm the effects of glucose-lowering agents on risk of stroke in patients with T2D. In summary, the effects of antidiabetic drugs on risk of stroke appear to be heterogeneous, with some therapies (pioglitazone, GLP-1 receptor agonists) conferring possible protection against ischaemic stroke, other classes showing a neutral impact (DPP-4 inhibitors, insulin) and some glucose-lowering agents being associated with an increased risk of stroke (sulphonylureas, possibly SGLT2 inhibitors, high-dose insulin in the presence of insulin resistance).

All-Cause Mortality in Patients With Diabetes Under Treatment With Dapagliflozin: A Population-Based, Open-Cohort Study in The Health Improvement Network Database

CONTEXT

Empagliflozin was found to decrease mortality in patients with type 2 diabetes mellitus (T2DM) and a prior cardiovascular disease (CVD) event.

OBJECTIVES

To establish whether these benefits can be replicated in a real-world setting, should be expected with the use of dapagliflozin, and apply to T2DM patients at low risk of CVD.

DESIGN

General practice, population-based, retrospective cohort study (January 2013 to September 2015).

SETTING

The Health Improvement Network database.

PARTICIPANTS

A total of 22,124 T2DM patients (4444 exposed to dapagliflozin; 17,680 unexposed T2DM patients) matched for age, sex, body mass index, T2DM duration, and smoking.

MAIN OUTCOME MEASURES

The primary outcome was all-cause mortality (high and low risk for CVD) in the total study population, expressed as the adjusted incidence rate ratio (aIRR) with 95% confidence intervals (CIs). As a secondary analysis in the low-risk population, all-cause mortality and incident CVD were considered.

RESULTS

Patients with T2DM exposed to dapagliflozin were significantly less likely to die of any cause (aIRR: 0.50; 95% CI: 0.33 to 0.75; P = 0.001). Similarly, in low-risk patients, death from any cause was significantly lower in the cohort exposed to dapagliflozin (aIRR: 0.44; 95% CI: 0.25 to 0.78; P = 0.002). The difference in the risk of incident CVD did not reach statistical significance between groups in low-risk patients (aIRR: 0.89; 95% CI: 0.61 to 1.31; P = 0.546).

CONCLUSIONS

Patients with T2DM who were exposed to dapagliflozin had a lower risk of death from any cause irrespective of baseline CVD status.

Cardiovascular outcome studies with incretin-based therapies: Comparison between DPP-4 inhibitors and GLP-1 receptor agonists

Dipeptidyl peptidase-4 inhibitors (DPP-4is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) represent two distinct classes of incretin-based therapies used for the treatment of type 2 diabetes. Non-inferiority versus placebo was shown in large prospective cardiovascular outcome trials in patients with high cardiovascular risk: SAVOR-TIMI 53 (saxagliptin), EXAMINE (alogliptin), and TECOS (sitagliptin); ELIXA (lixisenatide), LEADER (liraglutide) and SUSTAIN 6 (semaglutide). The promises raised by meta-analyses of phase 2-3 trials with DPP-4is were non confirmed as no cardiovascular protection could be evidenced. However, LEADER showed a significant reduction in major cardiovascular events, myocardial infarction, cardiovascular and all-cause mortality in patients treated by liraglutide compared to placebo. These positive results contrasted with the non-inferiority results with lixisenatide in ELIXA. They were partially confirmed with semaglutide in SUSTAIN 6 despite the absence of reduction in cardiovascular mortality. Hospitalisation for heart failure was not increased except with saxagliptin in SAVOR-TIMI 53. The reasons for different outcomes between trials remain largely unknown as well as the precise underlying mechanisms explaining the cardiovascular protection by liraglutide. The clinical relevance of results with DPP-4is and GLP-1RAs is discussed. Ongoing trials with linagliptin and several once-weekly GLP-1RAs should provide new insights into remaining fundamental questions.

Pharmacokinetic drug evaluation of saxagliptin plus dapagliflozin for the treatment of type 2 diabetes

INTRODUCTION

Combining a dipeptidyl peptidase-4 inhibitor and a sodium-glucose cotransporter type 2 inhibitor is an attractive option to treat hyperglycaemia in type 2 diabetes. Areas covered: The saxagliptin plus dapagliflozin combination is carefully analysed, focusing on: 1) pharmacokinetic properties, 2) pharmacodynamics data, and 3) results of randomised controlled trials (dual combination versus either monotherapy, sequential therapy saxagliptin added to dapagliflozin or dapagliflozin added to saxagliptin). Expert opinion: Pharmacokinetic findings demonstrate the absence of drug-drug interaction and the bioequivalence of the FDC compared with separated tablets. Pharmacodynamic observations confirm a complementary mode of action of the two agents. Dual saxagliptin-dapagliflozin therapy is more potent than either monotherapy. It may be used as an initial combination, although this approach remains debatable and should probably be reserved in case of high glycated hemoglobin, or a stepwise strategy, according to a personalized approach. The developed saxagliptin-dapagliflozin FDC may simplify anti-hyperglycemic therapy and improve drug compliance.

Understanding and overcoming metformin gastrointestinal intolerance

Metformin is the most widely prescribed drug for patients with type 2 diabetes mellitus and the first-line pharmacological option as supported by multiple international guidelines, yet a rather large proportion of patients cannot tolerate metformin in adequate amounts because of its associated gastrointestinal (GI) adverse events (AEs). GI AEs typically encountered with metformin therapy include diarrhoea, nausea, flatulence, indigestion, vomiting and abdominal discomfort, with diarrhoea and nausea being the most common. Although starting at a low dose and titrating slowly may help prevent some GI AEs associated with metformin, some patients are unable to tolerate metformin at all and it may also be difficult to convince patients to start metformin again after a bout of GI AEs. Despite this clinical importance, the underlying mechanisms of the GI intolerance associated with metformin are poorly known. In the present review, we discuss: the epidemiology of metformin-associated GI intolerance and its underlying mechanisms; genotype variability and associated factors affecting metformin GI intolerance, such as comorbidities, co-medications and bariatric surgery; clinical consequences and therapeutic strategies to overcome metformin GI intolerance. These strategies include appropriate titration of immediate-release metformin, use of extended-release metformin, the promise of delayed-release metformin and gut microbiome modulators, as well as alternative pharmacological therapies when metformin cannot be tolerated at all. Given the available data, all efforts should be made to maintain metformin before considering a shift to another drug therapy.

Effects of reducing blood pressure on renal outcomes in patients with type 2 diabetes: Focus on SGLT2 inhibitors and EMPA-REG OUTCOME

Empagliflozin, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor, has enabled remarkable reductions in cardiovascular and all-cause mortality as well as in renal outcomes in patients with type 2 diabetes (T2D) and a history of cardiovascular disease in the EMPA-REG OUTCOME. These results have been attributed to haemodynamic rather than metabolic effects, in part due to the osmotic/diuretic action of empagliflozin and the reduction in arterial blood pressure (BP). The present narrative review includes the results of meta-analyses of trials evaluating the effects on renal outcomes of lowering BP in patients with T2D, with a special focus on the influence of baseline and achieved systolic BP, and compares the renal outcome results of the EMPA-REG OUTCOME with those of other major trials with inhibitors of the renin-angiotensin system in patients with T2D and the preliminary findings with other SGLT2 inhibitors, and also evaluates post hoc analyses from the EMPA-REG OUTCOME of special interest as regards the BP-lowering hypothesis and renal function. While systemic BP reduction associated to empagliflozin therapy may have contributed to the renal benefits reported in EMPA-REG OUTCOME, other local mechanisms related to kidney homoeostasis most probably also played a role in the overall protection observed in the trial.

Renal, metabolic and cardiovascular considerations of SGLT2 inhibition

The kidney has a pivotal role in maintaining glucose homeostasis by using glucose as a metabolic fuel, by producing glucose through gluconeogenesis, and by reabsorbing all filtered glucose through the sodium-glucose cotransporters SGLT1 and SGLT2 located in the proximal tubule. In patients with diabetes, the maximum glucose reabsorptive capacity (Tm_G) of the kidney, as well as the threshold for glucose spillage into the urine, are elevated, contributing to the pathogenesis of hyperglycaemia. By reducing the Tm_G and, more importantly, the threshold of glucosuria, SGLT2 inhibitors enhance glucose excretion, leading to a reduction in fasting and postprandial plasma glucose levels and improvements in both insulin secretion and insulin sensitivity. The beneficial effects of SGLT2 inhibition extend beyond glycaemic control, however, with new studies demonstrating that inhibition of renal glucose reabsorption reduces blood pressure, ameliorates glucotoxicity and induces haemodynamic effects that lead to improved cardiovascular and renal outcomes in patients with type 2 diabetes mellitus. In this Review we examine the role of SGLT2 and SGLT1 in the regulation of renal glucose reabsorption in health and disease and the effect of SGLT2 inhibition on renal function, glucose homeostasis, and cardiovascular disease.

Effects of reducing blood pressure on cardiovascular outcomes and mortality in patients with type 2 diabetes: Focus on SGLT2 inhibitors and EMPA-REG OUTCOME

Empagliflozin, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor, has shown a remarkable reduction in cardiovascular and all-cause mortality in patients with type 2 diabetes (T2D) and antecedents of cardiovascular disease in the EMPA-REG OUTCOME trial. This effect has been attributed to a hemodynamic rather than a metabolic effect, partly due to the osmotic/diuretic effect of empagliflozin and to the reduction in arterial blood pressure. The present review will: (1) summarize the results of specific studies having tested the blood pressure lowering effects of SGLT2 inhibitors; (2) describe the results of meta-analyses of trials having evaluated the effects on mortality and cardiovascular outcomes of lowering blood pressure in patients with T2D, with a special focus on baseline and target blood pressures; (3) compare the cardiovascular outcome results in EMPA-REG OUTCOME versus other major trials with antihypertensive agents in patients with T2D; and (4) evaluate post-hoc analyses from EMPA-REG OUTCOME, especially subgroups of patients of special interest regarding the blood pressure lowering hypothesis. Although BP reduction associated to empagliflozin therapy may partly contribute to the benefits reported in EMPA-REG OUTCOME, other mechanisms most probably play a greater role in the overall CV protection and reduction in mortality observed in this trial.

SGLT2 Inhibitors: Benefit/Risk Balance

Inhibitors of sodium-glucose cotransporters type 2 (SGLT2) reduce hyperglycemia by increasing urinary glucose excretion. They have been evaluated in patients with type 2 diabetes treated with diet/exercise, metformin, dual oral therapy or insulin. Three agents are available in Europe and the USA (canagliflozin, dapagliflozin, empagliflozin) and others are commercialized in Japan or in clinical development. SGLT2 inhibitors reduce glycated hemoglobin, with a minimal risk of hypoglycemia. They exert favorable effects beyond glucose control with consistent body weight, blood pressure, and serum uric acid reductions. Empagliflozin showed remarkable reductions in cardiovascular/all-cause mortality and in hospitalization for heart failure in patients with previous cardiovascular disease. Positive renal outcomes were also shown with empagliflozin. Mostly reported adverse events are genital mycotic infections, while urinary tract infections and events linked to volume depletion are rather rare. Concern about a risk of ketoacidosis and bone fractures has been recently raised, which deserves caution and further evaluation.

Closing the knowledge gap on cardiovascular disease in type 2 diabetes: the EMPA-REG OUTCOME trial and beyond

Type 2 diabetes mellitus (T2DM) is associated with marked cardiovascular (CV) morbidity and mortality, including heart failure (HF). Until recently, an oral glucose-lowering agent that improved hyperglycemia as well as provided CV benefits in patients with T2DM and cardiovascular disease (CVD) was lacking. The newest class of glucose-lowering agents, sodium glucose cotransporter 2 (SGLT2) inhibitors, includes canagliflozin, dapagliflozin, and empagliflozin. Prior to the release of the LEADER trial results, the recent EMPA-REG OUTCOME study was the only dedicated CV trial to demonstrate a reduction in major adverse cardiac events, CV mortality, and all-cause mortality and a reduction in hospitalization for HF with empagliflozin, given on top of standard-of-care therapy in patients with T2DM and CVD. This paper summarizes the results from EMPA-REG OUTCOME and discusses their significance and clinical implications.

Sodium-glucose cotransporter 2 inhibition and health benefits: The Robin Hood effect

This review discusses two distinct, yet related, mechanisms of sodium-glucose cotransporter 2 (SGLT2) inhibition: Calorie restriction mimicry (CRM) and pro-ketogenic effect, which may explain their cardiovascular benefits. We term these adaptive CRM and pro-ketogenic effects of SGLT2 inhibition, the Robin Hood hypothesis. In English history, Robin Hood was a "good person," who stole from the rich and helped the poor. He supported redistribution of resources as he deemed fit for the common good. In a similar fashion, SGLT2 inhibition provides respite to the overloaded glucose metabolism while utilizing lipid stores for energy production.

DPP-4 inhibitor plus SGLT-2 inhibitor as combination therapy for type 2 diabetes: from rationale to clinical aspects

INTRODUCTION

Type 2 diabetes (T2D) is a complex disease with multiple defects, which generally require a combination of several pharmacological approaches to control hyperglycemia. Combining a dipeptidyl peptidase-4 inhibitor (DPP-4i) and a sodium-glucose cotransporter type 2 inhibitor (SGT2i) appears to be an attractive approach. Area covered: An extensive literature search was performed to analyze the pharmacokinetics, pharmacodynamics and clinical experience of different gliptin-gliflozin combinations. Expert opinion: There is a strong rationale for combining a DPP-4i and a SGLT2i in patients with T2D because the two drugs exert different and complementary glucose-lowering effects. Dual therapy (initial combination or stepwise approach) is more potent than either monotherapy in patients treated with diet and exercise or already treated with metformin. Combining the two pharmacological options is safe and does not induce hypoglycemia. The additional glucose-lowering effect is more marked when a gliflozin is added to a gliptin than when a gliptin is added to a gliflozin. Two fixed-dose combinations (FDCs) are already available (saxagliptin-dapagliflozin and linagliptin-empagliflozin) and others are in current development. Bioequivalence of the two compounds given as FDC tablets was demonstrated when compared with coadministration of the individual tablets. FDCs could simplify the anti-hyperglycaemic therapy and improve drug compliance.

Sodium-glucose cotransporter 2 inhibitors and cardiovascular outcomes

Type 2 diabetes mellitus (T2DM) is associated with an elevated risk of cardiovascular (CV) morbidity and mortality. Furthermore, many patients with T2DM have comorbidities that are risk factors for CV disease. While intensive glucose control reduces the risk of diabetic microvascular complications, its relationship to CV outcomes remains unclear. Consequently, the management of CV risk factors in patients with T2DM is complex, and factors other than blood glucose must be considered. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, a class of oral glucose-lowering agents, are associated with reductions in blood pressure and body weight, in addition to decreasing hyperglycemia, and therefore have the potential to reduce CV risk in patients with T2DM. The clinical trial results of SGLT2 inhibitors regarding CV safety and outcomes are discussed, including data from the recently published EMPA-REG OUTCOME study. This trial was the first dedicated CV outcomes study to demonstrate that a glucose-lowering agent lowered CV mortality and all-cause mortality, and reduced hospitalization for heart failure in patients with T2DM at high risk of CV events.