[A new era for glucagon-like peptide-1 receptor agonists]

Glucagon-like peptide-1 (GLP-1) receptor agonists have a privileged place in the management of type 2 diabetes (T2D). They not only improve glucose control without inducing hypoglycaemia and trigger weight loss, but also protect against atherosclerotic cardiovascular disease. Increasing the dose of three of them (liraglutide, semaglutide, dulaglutide) allows better glycaemic results and of potential interest a greater weight reduction. Liraglutide at a daily dose of 3.0 mg and semaglutide at a weekly dose of 2.4 mg received the indication for the therapy of obesity. A recent innovation consists in the development of dual unimolecular agonists that target GLP-1 and GIP («glucose-dependent insulinotropic polypeptide») receptors (tirzepatide) or GLP-1 and glucagon receptors (cotadutide). Tirzepatide, in the SURPASS programme, showed impressive reductions in glycated haemoglobin level and body weight, greater than those observed with dulaglutide or semaglutide. Tirzepatide received the indication of the treatment of T2D and is currently tested in obesity (SURMOUNT programme). Interestingly, triagonists GIP/GLP-1/glucagon are currently developed for the management of T2D and obesity, with also perspectives for treating metabolic-associated fatty liver disease.

Hypolipidemic effect of β-caryophyllene in high fat diet and fructose induced type-2 diabetic adult male rats

Skeletal muscle is responsible for the majority of insulin-stimulated whole-body glucose elimination, under normal circumstances. High dietary fat consumption increases stored fat mass and is a major risk factor for metabolic disorders. The conventional pharmacological treatments are associated with many adverse side effects and high rates of secondary failure which lead to an increasing demand for natural products with anti-diabetic activity and lesser side effects. β-Caryophyllene is a naturally occurring sequiterpene that may be found in cannabis and a range of culinary herbs and spices. It contains antioxidant, anti-inflammatory, and anti-lipidemic effects, among others. However, the effect of β-Caryophyllene on glucose absorption and oxidation, is yet unknown. Hence, the current study was intended to investigate the anti-diabetic impact of β-Caryophyllene in type-2 diabetes caused by a high-fat diet. To evaluate its anti-diabetic efficacy, high fat diet and fructose-induced type-2 diabetic rats were administered an effective dosage of β-Caryophyllene (200 mg/kg b.wt, orally for 30 days). The treatment of diabetes-induced rats with β-Caryophyllene restored the altered levels of blood glucose, serum insulin as well as lipid parameters. Our findings show that β-caryophyllene improves glycemia control by alleviating dyslipidemia in type-2 diabetic rats. From the present findings, it is evident that β-caryophyllene can be used as an anti-diabetic drug.

[Prescribing a SGLT2 inhibitor for treating heart failure without inducing hypoglycaemia]

Sodium-glucose cotransporter type 2 inhibitors (SGLT2i or gliflozins) improve the prognosis of patients with heart failure, independently of the presence of diabetes. They are now recommended for the treatment of heart failure in international guidelines. The addition of a gliflozin driven by such a cardiological indication may require some adjustment of the antidiabetic therapy. The aim of this concise article is to discuss the potential risk of hypoglycaemia, highly deleterious in fragile patients at risk, following the prescription of a gliflozin in patients with heart failure. Different clinical situations will be considered, both in nondiabetic patients and in patients with type 2 diabetes already treated with a variety of antihyperglycaemic agents, metformin, sulphonylureas, gliptins, GLP-1 receptor agonists and insulin.

[About the safety profile of SGLT2 inhibitors]

Since their launch, sodium-glucose cotransporter type 2 inhibitors (SGLT2is) were suspected to be associated with various adverse events. They contributed to delay, as in France, or to restrict the use of this new pharmacological class in clinical practice, despite remarkable results reported in large cardiovascular or renal clinical trials. This article is devoted to three major adverse events that were imputed to SGLT2is : lower-limb extremity amputations, euglycaemic ketoacidosis and acute kidney injuries. In contrast to pharmacovigilance reports that raised suspicion, analysis of all data from the literature, either placebo-controlled trials or retrospective observational cohort studies, led to rather reassuring conclusions. The incidence of amputations does not appear to be increased while cases of acute kidney injury are reduced instead of increased as suspected earlier. Ketoacidosis events are almost doubled with SGLT2is versus comparators, yet their incidence remains extremely low among patients with type 2 diabetes. Of note, this potentially severe complication contributes to the denial of marketing authorization and reimbursement of SGLT2is in the population with type 1 diabetes.

[From the discovery of phlorizin (a Belgian story) to SGLT2 inhibitors]

Most physicians do not know, or do not remember, the name of phlorizin. Hence this molecule has a major historical importance because it was the precursor of gliflozins, a new class of oral antidiabetic drugs with recent therapeutic perspectives beyond diabetes. This article recalls the history of phlorizin: its discovery in the 19th century by De Koninck and Stas, the demonstration of its ability to induce glucosuria and reduce hyperglycaemia by von Mering, its use to demonstrate the concept of glucose toxicity by the team of DeFronzo and finally the development of selective (phlorizin being not selective) sodium-glucose cotransporter type 2 inhibitors (gliflozins) which block glucose reabsorption in renal tubules. Gliflozins have increasing therapeutic indications, not only in type 2 diabetes, but also in cardiology and nephrology among non-diabetic people with heart failure or renal insufficiency.

[SGLT2 inhibitors and RAAS blockers : similarities, differences and complementarity]

Both renin-angiotensin-aldosterone system inhibitors (RAASi) and sodium-glucose cotransporter type 2 inhibitors (SGLT2i, gliflozins) reduce the risk of heart failure and of progressing towards end-stage renal disease, especially in patients with type 2 diabetes (T2D). Positive results reported in patients with T2D have been confirmed in people without diabetes. These two pharmacological classes now occupy a privileged place in international guidelines, in diabetology, cardiology and nephrology. The present article describes similarities and differences between these two types of medications. It emphasizes the importance of combining both approaches in order to optimize the cardiovascular and renal prognosis, while maintaining a good safety profile.

[Continuing or stopping metformin in patients with type 2 diabetes exposed to SARS-CoV-2 ?]

Both obesity and type 2 diabetes (T2D) are recognized risk factors for developing a more severe form of COVID-19, with a higher death rate. Metformin is considered as the first-line medication for the treatment of T2D, especially in obese patients. Beyond its glucose-lowering activity, metformin exerts pleiotropic effects, among which an anti-inflammatory effect that could be beneficial. However, metformin is contraindicated in case of severe renal insufficiency, liver failure and/or unstable heart failure, because of a risk of lactic acidosis. Yet, COVID-19, besides the well-known pneumonia that can be responsible for severe hypoxemia, may be associated with multisystemic organ failure, among which kidneys, liver and heart. Thus, the question arises whether metformin, which represents the background therapy in above 80 % of patients with T2D, should be continued in patients exposed to SARS-CoV-2 or instead be stopped. This article summarizes the most important results of observational studies, which all argue for a beneficial effect of metformin therapy that is associated with a significant reduction in mortality among hospitalized patients with T2D due to COVID-19. Finally, some practical advices will be given.

[SGLT2 inhibitors in patients with chronic kidney disease : from clinical trials to guidelines and new prospects for clinical practice]

Sodium-glucose cotransporter type 2 inhibitors (iSGLT2 or gliflozins) exert their antidiabetic action through a specific renal mechanism, by inhibiting tubular glucose reabsorption. These agents have proven their efficacy to reduce major cardiovascular events and hospitalisation for heart failure, but also the progression of chronic kidney disease (CKD), in patients with type 2 diabetes (T2DM) at high risk, independently of glucose control. While the glucose-lowering effect of iSGLT2 is decreasing with the decline of estimated glomerular filtration rate (eGFR), both cardiovascular and renal protections remain present until an eGFR as low as 30 ml/min/1,73 m². These effects were demonstrated in several meta-analyses and in two trials specifically dedicated to renal outcomes in patients with CKD and macroalbuminuria : CREDENCE with canagliflozin and Dapa-CKD with dapagliflozin. In addition, Dapa-CKD showed similar positive results whatever the presence or absence of T2DM. Safety profile of SGLT2is among patients with CKD is good and similar to that of patients with normal renal function. These favourable findings led to a privileged place of SGLT2i in recent international guidelines promoted by diabetologists, cardiologists and nephrologists. Current restrictive criteria for the prescription and reimbursement of SGLT2i in Belgium according to eGFR level (initiation only if eGFR superior to 60 and interruption if eGFR inferior to 45 ml/min/1.73 m²) should be enlarged very soon owing to convincing results of published controlled trials.

[A revolution in the management of type 2 diabetes : antidiabetic agents providing a cardiovascular and renal protection independently of glucose control !]

Type 2 diabetes is a complex disease with an increasing prevalence and a huge morbidity and premature mortality, essentially due to cardiovascular and renal complications. Classical glucose-lowering agents (metformin, sulphonylureas) exert little protective effects on these complications so that emphasis has been put on a multifactorial management targeting all risk factors. Gliptins offer the advantage of an excellent tolerance profile, with no hypoglycaemia or weight gain, but have not shown any specific cardiovascular or renal protection. Over the last decade, new antidiabetic medications (glucagon-like peptide-1 receptor agonists and gliflozins) have demonstrated a cardiovascular and renal protection, independently of glucose control. These data of evidence-based medicine have revolutionized the therapeutic approach of patients with type 2 diabetes who are at high risk of atherosclerotic cardiovascular disease, heart failure and progressive renal disease. Unexpectedly, the protective effect of gliflozins is currently investigated in patients with heart failure or renal disease, in the absence of diabetes.

[Extended indications for antidiabetic agents with cardio-renal protection in updated international recommendations for themanagement of at risk patients with type2 diabetes]

The strategy for the management of type 2 diabetes (T2D) has been updated late 2019-2020 by a group of experts of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). The indications of two pharmacological classes that have demonstrated a cardiovascular and renal protection, i.e. sodium-glucose cotransporter type 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1AR), are now extended because of the favourable results of recent clinical trials. In patients with T2D at high cardiovascular risk (even without previous event, but with indicators of atherosclerotic disease), the addition of these antidiabetic agents to metformin background therapy is now recommended independently of the glycated haemo¬globin (HbA1c) level. For SGLT2i, the prescription may be extended to patients with an estimated glomerular filtration rate down to 30 (instead of 60) ml/min/1.73 m², in particular in patients with progressive renal disease and albuminuria and in patients at risk of heart failure, especially if left ventricular ejection fraction is reduced. However, these new proposals could not be applied stricto sensu because of strict reimbursement criteria based upon HbA1c currently applied in our country.

[Which injectable therapy after failure of oral antidiabetic agents in type 2 diabetes ?]

The shift to injection therapy, after failure of oral antidiabetic agents, is often considered as a difficult step by both the patient with type 2 diabetes and the physician, a situation that may lead to clinical inertia. Schematically, two options may be considered, either starting insulin therapy with a preference for basal insulin analogues, or adding a glucagon-like peptide-1 receptor agonist (GLP-1 RA). Each option has its advantages and disadvantages, which opens the road to personalized medicine. Nevertheless, the preference is increasingly given to GLP-1 AR, yet this solution is more limited by reimbursement conditions. A combination of the two approaches is also possible, with the recent commercialisation of fixed-ratio specialities combining a basal insulin analogue and a GLP-1 RA. This clinical case offers the opportunity to discuss all these different therapeutic options in a patient with poorly controlled type 2 diabetes despite a combination of oral antidiabetic agents, taking also into account the current conditions for reimbursement in Belgium.

[Canaglifozin results in cardiovascular and renal protection in patients with type 2 diabetes : from CANVAS to CREDENCE]

Canagliflozin, a sodium-glucose cotransporter type 2 inhibitor, has been evaluated in two large clinical trials, CANVAS that focused on cardiovascular (CV) risk and CREDENCE that focused on renal risk. CANVAS recruited type 2 diabetic patients (T2D) at high CV risk (65 % in secondary prevention) and demonstrated that canagliflozin significantly reduces major CV events, hospitalisations for heart failure and renal outcomes when compared to placebo. CREDENCE specifically enrolled T2D patients with albuminuric renal disease (50 % in secondary CV prevention). This trial confirmed the cardiovascular protection reported in CANVAS with canagliflozin and more specifically demonstrated a renal protection, including a reduced progression towards end-stage renal disease, in this particular population. Finally, CREDENCE did not observe the increased risk for bone fractures and lower-limb amputations previously reported in CANVAS. Globally, these two studies emphasize a favourable benefit/risk balance of canagliflozin in a T2D population at CV or renal risk, including in patients with a glomerular filtration rate comprised between 30 et 60 ml/min/1.73 m².

[How I manage a patient with type 2 diabetes not well controlled with a metformin plus gliptin combination]

Type 2 diabetes (T2D) is an evolving disease that requires therapeutic adjustments to maintain adequate glucose control in the long run. An increasing number of patients with T2D are treated with a metformin plus gliptin (DPP-4 Inhibitor) combination, especially those for whom a sulfonylurea is avoided because of a risk of hypoglycaemia. When this dual metformin-gliptin therapy becomes insufficient to reach or maintain adequate glucose control, three solutions may be considered : the addition of a gliflozin (SGLT2 inhibitor), the replacement of the gliptin by a glucagon-like peptide-1 receptor agonist or the addition of a basal insulin whose posology should be progressively up-titrated according to fasting glycaemia. This article describes the pro and contra arguments of these three therapeutic regimens. According to the recent data of the literature, the triple oral therapy combining metformin, a gliptin and a gliflozin appears to offer a favourable alternative in terms of efficacy, tolerance, ease of use, patient adherence and cost.

[Semaglutide, once weekly GLP-1 receptor agonist (Ozempic®)]

Semaglutide (Ozempic®) is a new once-weekly agonist of glucagon-like peptide-1 receptors (GLP-1 AR) indicated in the treatment of type 2 diabetes (T2D). Phase III clinical trials of the SUSTAIN programme demonstrated both the efficacy and safety of semaglutide in patients with T2D treated by diet and exercise, oral antidiabetic agents or even insulin. Direct and indirect comparative clinical trials showed that semaglutide (subcutaneous 0.5 or 1.0 mg once weekly) exerts a better glucose-lowering activity and a greater weight loss than other GLP-1 AR. Presented as prefilled pens for subcutaneous injection, semaglutide is currently reimbursed in Belgium after failure of antidiabetic therapy including metformin (HbA1c superior to 7,5 % or 58 mmol/mol) in T2D patients with body mass index ? 30 kg/m².

[Basal insulin degludec (Tresiba®)]

Insulin degludec (Tresiba®) is characterized by an original mode of prolonged and continuous insulin release after its subcutaneous injection. Thereby, it has a very long glucose-lowering effect, around 42 hours, and a better reproducibility from both a pharmacokinetic and pharmacodynamic point of view. Its efficacy and safety have been assessed in the phase 3 clinical programme BEGIN as compared with insulin glargine U100, in patients with type 1 diabetes (T1D) and type 2 (T2D). For a similar glucose control (reduction in glycated haemoglobin), less hypoglycaemic episodes were recorded, including severe hypoglycaemia, during the nocturnal period, with insulin degludec than with insulin glargine U100. This clinical benefit has been confirmed in the complementary SWITCH programme in T1D and T2D patients at higher risk of hypoglycaemia, in the double-blind cardiovascular outcome trial DEVOTE in T2D patients at high cardiovascular risk and in real-life conditions in the observational European EU-TREAT study in patients with T1D and T2D. Insulin degludec (Tresiba®) is indicated and reimbursed for the treatment of patients with T1D, combined with a prandial insulin, and T2D, alone or combined with oral antidiabetic agents, a glucagon-like peptide-1 receptor agonist or a short-acting insulin.

[Focus on empagliflozin : post hoc analyses of the cardiovascular outcome trial EMPA-REG OUTCOME]

EMPA-REG OUTCOME trial studied the cardiovascular safety of empagliflozin, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor, compared to placebo, in patients with type 2 diabetes and high cardiovascular risk. It showed a significant reduction of major cardiovascular events (-14 %), cardiovascular mortality (-38 %), all-cause death (-32 %), hospitalisations for heart failure (-35 %) and progression of renal disease (-39 %). This article proposes an update, almost 4 years after the original publication, of recent post hoc analyses of this landmark study.

[Basal insulin glargine-lixisenatide fixed ratio combination (Suliqua®)]

Suliqua® (iGlarLixi) is a fixed ratio combination of basal insulin glargine U100 and the glucagon-like peptide-1 (GLP-1) receptor agonist lixisenatide. Both molecules exert complementary antihyperglycaemic effects : insulin glargine mainly targets fasting glycaemia while lixisenatide mainly targets postprandial hyperglycaemia. Thus, iGlarLixi is associated with a greater reduction in glycated haemoglobin (HbA1c) than each individual component and thereby results in a greater percentage of patients reaching HbA1c ? 7 %. It has a good tolerance profile, with a more favourable effect on body weight compared with insulin glargine alone and less gastrointestinal adverse effects when compared with lixisenatide alone, because of a more progressive titration of the GLP-1 receptor agonist component. iGlarLixi (Suliqua®) is presented as two different prefilled pens, one allowing to titrate glargine up to 40 IU/day, the other up to 60 IU/day, both with lixisenatide uptitrated to a maximum of 20 µg/day. This dual presentation facilitates a personalized approach according to patient's needs. Suliqua® is currently reimbursed, under conditions, for the management of type 2 diabetes not well controlled with basal insulin associated or not with oral antidiabetic agents.

Paradigm change according to the ADA-EASD consensus report 2018]

The strategy for the management of hyperglycaemia in type 2 diabetes was updated in October 2018 by a group of experts of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). They are triggered by the results of cardiovascular outcome trials published since 2015, which demonstrated a cardiovascular (and renal) protection with two classes of medications, SGLT2 inhibitors (gliflozins) and some GLP-1 receptor agonists (mainly liraglutide) in patients with established cardiovascular disease. Thus, after failure of lifestyle and metformin, the addition of one of these agents is recommended in presence of atherosclerotic cardiovascular disease. In case of heart failure or renal disease, the preference is given to a SGLT2 inhibitor, provided that estimated glomerular filtration rate is adequate (superior to 45-60 ml/min/1.73 m²). In all other patients, the choice is guided by the main objective, in concertation with the patient : to reduce the risk of hypoglycaemia (gliptin, gliflozin, pioglitazone or GLP1 receptor agonist), body weight excess (SGLT2 inhibitor or GLP-1 receptor) or medication cost (sulphonylurea, pioglitazone). If oral treatment is insufficient, the preference is now given to a GLP-1 receptor agonist rather than basal insulin. Thus, instead of a glucocentric and metabolic viewpoint predominant in the previous position statement, a paradigm change is proposed, focusing on cardiovascular and renal protection, within a patient-centred approach.

[Basal insulin degludec - liraglutide fixed ratio combination (Xultophy®)]

Xultophy® (IDegLira) is a fixed ratio combination of basal insulin degludec and glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide. Insulin degludec is characterized by an original mode of prolonged and continuous insulin diffusion after its subcutaneous injection. Thereby, it has a very long half-life, around 25 hours, and a better reproducibility from both a pharmacokinetic and pharmacodynamic point of view, with less hypoglycaemia, especially at night. Liraglutide is a well-known once-daily GLP-1 receptor agonist that showed a cardiovascular and renal protection in patients with type 2 diabetes at high cardiovascular risk. Both molecules exert complementary antihyperglycaemic effects, which allows a better glucose control, both in the fasting and postprandial states. IDegLira is more effective than another basal insulin regimen in reaching individualized glycated haemoglobin target, with a lower daily dose of insulin. It has a better tolerance profile, with a more favourable effect on body weight and less hypoglycaemia compared with a basal insulin and less gastrointestinal adverse effects when compared with liraglutide alone. Xultophy® is presented as a prefilled pen and is indicated in the management of type 2 diabetes not well controlled with basal insulin. The dose of IDegLira is progressively uptitrated, starting from 16 dose steps up to a maximum of 50 dose steps per day (corresponding to 50 IU insulin degludec and 1.8 mg liraglutide).

[Which place for thiazide and thiazide-like diuretics in patients with type 2 diabetes ?]

The use of thiazides as antihypertensive agents has been challenged because associated metabolic adverse events, including new-onset diabetes. However, these metabolic disturbances are less marked with low-dose of hydrochlorothiazide and with thiazide-like diuretics such as chlorthalidone and indapamide. In post hoc analyses of subgroups of patients with hypertension and type 2 diabetes, thiazide(-like) diuretics resulted in a significant reduction in cardiovascular events, all-cause mortality and hospitalization for heart failure compared to placebo. Furthermore, they were shown to be non-inferior to other antihypertensive agents, including blockers of the renin-angiotensin system in diabetic patients without albuminuria. Benefits attributed to thiazide(-like) diuretics (especially at low dose) in terms of cardiovascular protection outweigh the risk of worsening glucose control and inducing other metabolic disorders in patients with type 2 diabetes. Thus low dose thiazide(-like) drugs still play a major role in the treatment of hypertension in patients with type 2 diabetes.

[SGLT2 inhibitor or GLP-1 receptor agonist in a patient with type 2 diabetes and cardiovascular disease ?]

Two classes of antidiabetic agents have shown a cardiovascular and renal protection in patients with type 2 diabetes and high cardiovascular risk. Empagliflozin, a sodium-glucose cotransporter type 2 (SGLT2) inhibitor, and liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist, were granted a reduction of major cardiovascular events and mortality after the positive results of EMPA-REG OUTCOME and LEADER outcome trials, respectively. Protection mechanisms most probably differ between the two pharmacological classes and are perhaps complementary. The question that may arise in clinical practice is to know which drug should be selected between these two options in a patient with type 2 and established cardiovascular disease, before considering a potential combination. The aim of this article is to discuss about the best therapeutic choice according to the patient individual profile and the specificities of each molecule.

[Complementarity between randomised controlled trials and observational registries : the example of cardiovascular prevention with SGLT2 inhibitors]

Evidence-based medicine (EBM) is mainly supported by the results of randomised controlled trials (RCTs). If the latter offer guarantees of reliability, especially by minimizing the influence of confounding factors and potential biases, they also have limitations. Observational databases resulting from real life registries, if possible build in a prospective manner, may offer some solutions, but are also exposed to limitations. This article compares the advantages and disadvantages of the two sources of information, which ideally should be complementary. For the purpose of illustration, we shall compare the recent results of RCTs and of observational databases from multinational registries that investigated the effects of sodium-glucose cotransporter type 2 inhibitors (gliflozins) on cardiovascular outcomes in patients with type 2 diabetes.

[Use of oral glucose-lowering agents in patients with renal impairment]

Patients with type 2 diabetes (T2D) and chronic kidney disease (CKD) are increasingly numerous, especially in the elderly population. Surprisingly, this situation is often under-recognized or even neglected in clinical practice. Yet, most oral antidiabetic (OAD) agents have limitations in case of renal impairment, either because they require a dose reduction, or are contra-indicated mainly for safety reasons. This clinical case gives the opportunity to discuss the modalities of prescription and cautions to be taken when using most commonly prescribed OAD, metformin, insulin secretagogues (sulfonylureas, repaglinide), DPP-4 inhibitors (gliptins) and SGLT2 inhibitors, in a patient with T2D and CKD.

[Which antidiabetic agent in a patient with type 2 diabetes and heart failure ?]

Heart failure is raising an increasing interest in patients with type 2 diabetes. Indeed, they combine different risk factors for this complication and they have time to develop it because they survive longer due to a better prevention of atherothrombotic cardiovascular events. Beyond the classical therapy of heart failure, management should select the most suited glucose-lowering agents. Indeed, all do not have the same impact as some of them have proven their ability to reduce the risk of hospitalisation for heart failure whereas others are associated with an increased risk, either well proven or at least suspected. The aim of this clinical case is to discuss the use of glucose-lowering drugs in a patient with type 2 diabetes with or at risk to develop heart failure.