Rationale and design of a multicenter randomized controlled study to evaluate the preventive effect of ipragliflozin on carotid atherosclerosis: the PROTECT study

Effects of ipragliflozin on left ventricular diastolic function in patients with type 2 diabetes: A sub-analysis of the PROTECT trial

BACKGROUND

We hypothesized that the beneficial effects of sodium-glucose cotransporter-2 (SGLT2) inhibitors on diastolic function might depend on baseline left ventricular (LV) systolic function.

METHODS

To investigate the effects of SGLT2 inhibitors on LV diastolic function in patients with type 2 diabetes mellitus (T2DM), we conducted a post-hoc sub-study of the PROTECT trial, stratifying the data according to LV ejection fraction (LVEF) at baseline. After excluding patients without echocardiographic data at baseline or 24 months into the PROTECT trial, 31 and 38 patients with T2DM from the full analysis dataset of the PROTECT trial who received ipragliflozin or no SGLT2 inhibitor (control), respectively, were included. The primary endpoint was a comparison of the changes in echocardiographic parameters and N-terminal pro-brain natriuretic peptide levels from baseline to 24 months between the two groups stratified according to baseline LVEF.

RESULTS

Differences in diastolic functional parameters (e' and E/e') were noted between the two groups. Among the subgroups defined according to median LVEF values, those with higher LVEF (≥60 %) who received ipragliflozin appeared to have a higher e' and lower E/e' than did those who received the standard of care with no SGLT2 inhibitor, indicating longitudinal improvements between baseline and follow up (p = 0.001 and 0.016, respectively).

CONCLUSIONS

Ipragliflozin generally improved LV diastolic function in patients with type 2 diabetes, the extent of this improvement might appear to vary with LV systolic function.

Long-term effects of ipragliflozin on blood pressure in patients with type 2 diabetes: insights from the randomized PROTECT trial

Although previous reports have shown that sodium-glucose cotransporter-2 (SGLT2) inhibitors have a blood pressure (BP) lowering effect, relevant long-term data is limited. This study aimed to evaluate the effect of the SGLT2 inhibitor ipragliflozin on BP, and associations between BP reduction and changes in cardiometabolic variables in diabetic patients. This was a sub-analysis of the PROTECT trial, a multicenter, randomized, open-label study to assess if ipragliflozin delays carotid atherosclerosis in patients with type 2 diabetes. Participants were randomized to ipragliflozin and control groups. The primary endpoint of the present sub-analysis was the trajectory of systolic BP over 24 months. Correlations between systolic BP changes and cardiometabolic variables were also evaluated. A total of 232 eligible participants with well-balanced baseline characteristics were included in each study group. Throughout the 24-month study period, mean systolic BP was lower in the ipragliflozin group. At 24 months, a between-group difference (ipragliflozin minus control) in mean systolic BP change from baseline was -3.6 mmHg (95% confidence interval, -6.2 to -1.0 mmHg), and the reduction in systolic BP in the ipragliflozin group was consistent across subgroups examined. Changes in systolic BP significantly correlated with those in body mass index in the ipragliflozin group, while no significant correlations with other cardiometabolic variables tested were observed. In conclusion, ipragliflozin treatment was associated with BP reduction throughout the 24-month follow-up period as compared to control treatment. BP reduction correlated with weight loss, which might be one of the mechanisms for the BP lowering effect of SGLT2 inhibitors.

Long-term observation of estimated fluid volume reduction after the initiation of ipragliflozin in patients with type 2 diabetes mellitus: a sub-analysis from a randomized controlled trial (PROTECT)

BACKGROUNDS/AIM

Recent studies have shown that the addition of sodium-glucose co-transporter 2 (SGLT2) inhibitors gradually reduces the estimated fluid volume parameters in a broad range of patient populations, suggesting that this mediates the clinical benefits of SGLT2 inhibitors in preventing heart failure. Here, we sought to examine the long-term (24 months) effect of the SGLT2 inhibitor ipragliflozin on the estimated fluid volume parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

In this prespecified sub-analysis of the PROTECT (Prevention of Atherosclerosis by SGLT2 Inhibitor: Multicenter, Randomized Controlled Study) trial, which was an investigator-initiated, multicenter, prospective, randomized, open-label, clinical trial primarily designed to evaluate the effect of ipragliflozin treatment administered for 24 months on carotid atherosclerosis in patients with T2DM, we evaluated serial changes in estimated plasma volume (ePV, %) calculated using the Straus formula and estimated extracellular volume (eEV, mL) calculated by the body surface area by 24 months following the initiation of 50-mg ipragliflozin once daily and compared them with those following standard care for T2DM (non-SGLT2 inhibitor use).

RESULTS

This sub-analysis included 464 patients (ipragliflozin, n = 232; control, n = 232), a full analysis set of the PROTECT trial. In an analysis using mixed-effects models for repeated measures, relative to the control group, ipragliflozin significantly reduced ePV by - 10.29% (95% confidence interval [CI]  - 12.47% to - 8.11%; P < 0.001) at 12 months and - 10.76% (95% CI - 12.86% to - 8.67%; P < 0.001) at 24 months. Additionally, ipragliflozin significantly reduced eEV by - 190.44 mL (95% CI - 249.09 to - 131.79 mL; P < 0.001) at 12 months and - 176.90 mL (95% CI  - 233.36 to - 120.44 mL; P < 0.001) at 24 months. The effects of ipragliflozin on these parameters over 24 months were mostly consistent across various patient clinical characteristics.

CONCLUSIONS

This prespecified sub-analysis from the PROTECT trial demonstrated that ipragliflozin treatment, compared with the standard care for T2DM, reduced two types of estimated fluid volume parameters in patients with T2DM, and the effect was maintained for 24 months. Our findings suggest that SGLT2 inhibitor treatment regulates clinical parameters incorporated into the calculating formulas analyzed and consequently fluid volume status for the long-term, and this may be at least partly associated with clinical benefits from chronic use of SGLT2 inhibitors. Trial registration Japan Registry of Clinical Trials, ID jRCT1071220089.

Lack of impact of ipragliflozin on endothelial function in patients with type 2 diabetes: sub-analysis of the PROTECT study

BACKGROUND

We assessed the impact of 24 months of treatment with ipragliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, on endothelial function in patients with type 2 diabetes as a sub-analysis of the PROTECT study.

METHODS

In the PROTECT study, patients were randomized to receive either standard antihyperglycemic treatment (control group, n = 241 ) or add-on ipragliflozin treatment (ipragliflozin group, n = 241) in a 1:1 ratio. Among the 482 patients in the PROTECT study, flow-mediated vasodilation (FMD) was assessed in 32 patients in the control group and 26 patients in the ipragliflozin group before and after 24 months of treatment.

RESULTS

HbA1c levels significantly decreased after 24 months of treatment compared to the baseline value in the ipragliflozin group, but not in the control group. However, there was no significant difference between the changes in HbA1c levels in the two groups (7.4 ± 0.8% vs. 7.0 ± 0.9% in the ipragliflozin group and 7.4 ± 0.7% vs. 7.3 ± 0.7% in the control group; P = 0.08). There was no significant difference between FMD values at baseline and after 24 months in both groups (5.2 ± 2.6% vs. 5.2 ± 2.6%, P = 0.98 in the ipragliflozin group; 5.4 ± 2.9% vs. 5.0 ± 3.2%, P = 0.34 in the control group). There was no significant difference in the estimated percentage change in FMD between the two groups (P = 0.77).

CONCLUSIONS

Over a 24-month period, the addition of ipragliflozin to standard therapy in patients with type 2 diabetes did not change endothelial function assessed by FMD in the brachial artery.

TRIAL REGISTRATION

Registration Number for Clinical Trial: jRCT1071220089 ( https://jrct.niph.go.jp/en-latest-detail/jRCT1071220089 ).

Effect of ipragliflozin on carotid intima-media thickness in patients with type 2 diabetes: a multicenter, randomized, controlled trial

AIMS

To examine the effects of a 24-month treatment with ipragliflozin on carotid intima-media thickness (IMT) in type 2 diabetes patients.

METHODS AND RESULTS

In this multicenter, prospective, randomized, open-label, and blinded-endpoint investigator-initiated clinical trial, adults with type 2 diabetes and haemoglobin A1C (HbA1c) of 6.0-10.0% (42-86 mmol/mol) were randomized equally to ipragliflozin (50 mg daily) and non-sodium-glucose cotransporter-2 (SGLT2) inhibitor use of standard-care (control group) for type 2 diabetes and were followed-up to 24 months. The primary endpoint was the change in mean common carotid artery IMT (CCA-IMT) from baseline to 24 months. A total of 482 patients were equally allocated to the ipragliflozin (N = 241) and control (N = 241) groups, and 464 patients (median age 68 years, female 31.7%, median type 2 diabetes duration 8 years, median HbA1c 7.3%) were included in the analyses. For the primary endpoint, the changes in the mean CCA-IMT from baseline to 24 months were 0.0013 [95% confidence interval (CI), -0.0155-0.0182] mm and 0.0015 (95% CI, -0.0155-0.0184) mm in the ipragliflozin and control groups, respectively, with an estimated group difference (ipragliflozin-control) of -0.0001 mm (95% CI, -0.0191-0.0189; P = 0.989). A group difference in HbA1c change at 24 months was also non-significant between the treatment groups [-0.1% (95% CI, -0.2-0.1); P = 0.359].

CONCLUSION

Twenty-four months of ipragliflozin treatment did not affect carotid IMT status in patients with type 2 diabetes recruited in the PROTECT study, relative to the non-SGLT2 inhibitor-use standard care for type 2 diabetes.

Cardiovascular benefits of sodium-glucose cotransporter 2 inhibitors in diabetic and nondiabetic patients

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) were developed as antidiabetic agents, but accumulating evidence has shown their beneficial effects on the cardiovascular system. Analyses of the EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) suggested that these benefits are independent of glycemic control. Several large-scale outcome trials of SGLT2i also showed cardiovascular benefits in nondiabetic patients, strengthening this perspective. Extensive animal and clinical studies have likewise shown that mechanisms other than the antihyperglycemic effect underlie the cardiovascular benefits. Recent clinical guidelines recommend the use of SGLT2i in patients with type 2 diabetes mellitus and cardiovascular diseases because of the proven cardiovascular protective effects. Since the cardiovascular benefits are independent of glycemic control, the therapeutic spectrum of SGLT2i will likely be extended to nondiabetic patients.

Anti-inflammatory effects of sodium-glucose co-transporter 2 inhibitors on atherosclerosis

Atherosclerosis is a very common macrovascular complication in type 2 diabetes mellitus, and cardiovascular disease is the primary cause of death in diabetes patients. Sodium-glucose cotransporter 2 inhibitors (SGLT-2i) are a newly identified class of drugs targeting the renal proximal tubules to increase glucose excretion. Large-scale clinical trials have confirmed the cardiovascular protective effects of SGLT inhibitors in patients with diabetes diagnosed with or at a higher risk of atherosclerotic cardiovascular disease. In addition to its direct effect on glycemic control, the function of SGLT-2i in the alleviation of volume load, renal protection, and reduction of inflammation plays an essential role in its therapeutic effect on atherosclerosis. SGLT-2i are known to decrease the levels of inflammatory factors in circulation and in arteries in situ, inhibit foam cell formation and macrophage infiltration, and sustain plaque stability, ultimately blocking the development and progression of atherosclerosis.

Rationale and design of an investigator-initiated, multicenter, prospective open-label, randomized trial to evaluate the effect of ipragliflozin on endothelial dysfunction in type 2 diabetes and chronic kidney disease: the PROCEED trial

Background

Type 2 diabetes (T2D) is associated with renal impairment and vascular endothelial dysfunction. Therefore, this pathological connection is an important therapeutic target. Recent cardiovascular and renal outcome trials demonstrated that sodium glucose cotransporter 2 inhibitors (SGLT2is) consistently reduced the risks of cardiovascular and renal events and mortality in patients with T2D and various other background risks including chronic kidney disease (CKD). However, the precise mechanisms by which SGLT2is accords these therapeutic benefits remain uncertain. It is also unknown whether these SGLT2is-associated benefits are associated with the amelioration of endothelial dysfunction in patients with T2D and CKD.

Methods

The PROCEED trial is an investigator-initiated, prospective, multicenter, open-label, randomized-controlled trial. The target sample size is 110 subjects. After they furnish informed consent and their endothelial dysfunction is confirmed from their decreased reactive hyperemia indices (RHI), eligible participants with T2D (HbA1c, 6.0–9.0%) and established CKD (30 mL/min/1.73 m² ≤ estimated glomerular filtration ratio [eGFR] < 60 and/or ≥ urine albumin-to-creatinine ratio 30 mg/g Cr) will be randomized (1:1) to receive either 50 mg ipragliflozin daily or continuation of background treatment (non-SGLT2i). The primary endpoint is the change in RHI from baseline after 24 weeks. To compare the treatment effects between groups, the baseline-adjusted means and their 95% confidence intervals will be estimated by analysis of covariance adjusted for HbA1c (< 7.0% or ≥ 7.0%), age (< 70 y or ≥ 70 y), RHI (< 1.67 or ≥ 1.67), eGFR (< 45 mL/min/1.73 m² or ≥ 45 mL/min/1.73 m²), and smoking status. Prespecified responder analyses will be also conducted to determine the proportions of patients with clinically meaningful changes in RHI at 24 weeks.

Discussion

PROCEED is the first trial to examine the effects of ipragliflozin on endothelial dysfunction in patients with T2D and CKD. This ongoing trial will establish whether endothelial dysfunction is a therapeutic target of SGLT2is in this population. It will also provide deep insights into the potential mechanisms by which SGLT2is reduced the risks of cardiovascular and renal events in recent outcome trials.

Trial registration Unique Trial Number, jRCTs071190054 (https://jrct.niph.go.jp/en-latest-detail/jRCTs071190054).

Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of the metabolic syndrome (MetS) and comprises one of the largest health threats of the twenty-first century. In this chapter, we review the current state of knowledge of NAFLD and underline the striking similarities with atherosclerosis. We first describe current epidemiological data showing the staggering increase of NAFLD numbers and its related clinical and economic costs. We then provide an overview of pathophysiological hepatic processes in NAFLD and highlight the systemic aspects of NAFLD that point toward metabolic crosstalk between organs as an important cause of metabolic disease. Finally, we end by highlighting the currently investigated therapeutic approaches for NAFLD, which also show strong similarities with a range of treatment options for atherosclerosis.

Clinical utility of carotid ultrasonography: Application for the management of patients with diabetes

Carotid ultrasonography is a non-invasive, simple and inexpensive modality to assess the severity of atherosclerosis. This article reviews related articles, summarizes the rationale for the application of carotid ultrasonography in clinical practice, and addresses the features and the limitations of carotid ultrasonography in cardiovascular risk prediction. Numerous large studies have confirmed that various carotid ultrasound measures, such as carotid intima-media thickness, the presence or absence of carotid plaque, plaque number and plaque area, can be independent predictors of cardiovascular diseases in individuals with and without diabetes mellitus. Furthermore, many studies showed that the use of carotid intima-media thickness (especially maximum intima-media thickness, including plaque thickness) and/or carotid plaque in addition to traditional risk factors significantly improved the prediction of the occurrence of cardiovascular diseases, while controversy remains. Several studies showed that the progression of carotid intima-media thickness also can be a surrogate end-point of cardiovascular events. However, the accumulated evidence has not been sufficient. Further study with sufficient power should be carried out. As plaque disruption, which plays a crucial role in the pathogenesis of cardiovascular events, is dependent on the content of lipid in the atheroma and the thickness of the fibrous cap, tissue characterization of a plaque might be useful for determining its fragility. Interestingly, recent studies have shown that ultrasonic tissue characterization of carotid lesions could improve the prediction ability of future cardiovascular diseases. Thus, carotid ultrasonography is a useful modality for better clinical practice of atherosclerosis in patients with diabetes.

Sodium-Glucose Cotransporter-2 Inhibition in Type 2 Diabetes Mellitus: A Review of Large-Scale Cardiovascular Outcome Studies and Possible Mechanisms of Benefit

Cardiovascular (CV) disease remains the leading cause of morbidity and mortality in individuals with type 2 diabetes mellitus (T2DM). However, conventional antihyperglycemic medications seem to have minimal effect on lowering CV risk despite achieving excellent reductions in glycated hemoglobin A1c and associated reductions in microvascular risk. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have emerged as noteworthy antihyperglycemic agents with concomitant CV and renal protection in T2DM patients. In this comprehensive review, we present the key CV findings from major large-scale outcome trials of SGLT2 inhibitors to date. We also review the mechanistic studies that might explain the CV benefits of SGLT2 inhibition in patients with T2DM.

SGLT2 Inhibitors and Cardiovascular Outcomes: Current Perspectives and Future Potentials

PURPOSE OF REVIEW

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been shown to exert benefit on cardiac outcomes. In this review, we provide updates on available clinical data, studies on potential mechanisms for the CV effects, as well as discuss potential clinical implications of these new findings.

RECENT FINDINGS

Since the publications of the EMPA-REG and CANVAS trials, large multi-national cohort studies have further shown the cardioprotective effects of SGLT2i. Moreover, new studies examining SGLT2i action on sodium-hydrogen exchanger proteins in both the heart and the kidney, on myocardial energetics and impact on inflammation and atherosclerosis continue to shed light on the multitude of pleotropic effects of these agents. Though more data is needed to substantiate the safety and efficacy, SGLT2i should be considered as a valuable therapy to help reduce CV risk in patients with diabetes. Ultimately, SGLT2i may have utility in preventing progression to diabetes or providing CV protection in patients who do not have diabetes.

Molecular Mechanisms Underlying the Cardiovascular Benefits of SGLT2i and GLP-1RA

PURPOSE OF REVIEW

In addition to their effects on glycemic control, two specific classes of relatively new anti-diabetic drugs, namely the sodium glucose co-transporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) have demonstrated reduced rates of major adverse cardiovascular events (MACE) in subjects with type 2 diabetes (T2D) at high risk for cardiovascular disease (CVD). This review summarizes recent experimental results that inform putative molecular mechanisms underlying these benefits.

RECENT FINDINGS

SGLT2i and GLP-1RA exert cardiovascular effects by targeting in both common and distinctive ways (A) several mediators of macro- and microvascular pathophysiology: namely (A1) inflammation and atherogenesis, (A2) oxidative stress-induced endothelial dysfunction, (A3) vascular smooth muscle cell reactive oxygen species (ROS) production and proliferation, and (A4) thrombosis. These agents also exhibit (B) hemodynamic effects through modulation of (B1) natriuresis/diuresis and (B2) the renin-angiotensin-aldosterone system. This review highlights that while GLP-1RA exert direct effects on vascular (endothelial and smooth muscle) cells, the effects of SGLT2i appear to include the activation of signaling pathways that prevent adverse vascular remodeling. Both SGLT2i and GLP-1RA confer hemodynamic effects that counter adverse cardiac remodeling.

Empagliflozin influences blood viscosity and wall shear stress in subjects with type 2 diabetes mellitus compared with incretin-based therapy

Background

Cardiovascular protection following empagliflozin therapy is not entirely attributable to the glucose lowering effect. Increased hematocrit might influence the shear stress that is the main force acting on the endothelium, regulating its anti-atherogenic function.

Objective

We designed the study with the aim of investigating the effect of empagliflozin on blood viscosity and shear stress in the carotid arteries. A secondary endpoint was the effect of empagliflozin on carotid artery wall thickness.

Methods

The study was a non-randomized, open, prospective cohort study including 35 type 2 diabetic outpatients who were offered empagliflozin or incretin-based therapy (7 liraglutide, 8 sitagliptin) in combination with insulin and metformin. Blood viscosity, shear stress and carotid wall thickness were measured at baseline and at 1 and 3 months of treatment. Blood viscosity was measured with a viscometer, and shear stress was calculated using a validated formula. Intima-media thickness (IMT) of the carotid artery was detected by ultrasound and was measured with dedicated software.

Results

Blood viscosity (4.87 ± 0.57 vs 5.32 ± 0.66 cP, p < 0.02) and shear stress significantly increased in the Empagliflozin group while no change was detected in the Control group (4.66 ± 0.56 vs 4.98 ± 0.73 cP, p = NS). IMT significantly decreased in the Empagliflozin group after 1 and 3 months (baseline: 831 ± 156, 1-month 793 ± 150, 3-month 766 ± 127 μm; p < 0.0001), while in the liraglutide group, IMT significantly decreased only after 3 months (baseline 879 ± 120; 1-month 861 ± 163; 3-month 802 ± 114 μm; p < 0.001). In the sitagliptin group, IMT remained almost unchanged (baseline 901 ± 135; 1-month 902 ± 129; 3-month 880 ± 140 μm; p = NS).

Conclusions

This study is the first to describe a direct effect of empagliflozin on blood viscosity and wall shear stress. Furthermore, IMT was markedly reduced early on in the Empagliflozin group.

Dapagliflozin acutely improves endothelial dysfunction, reduces aortic stiffness and renal resistive index in type 2 diabetic patients: a pilot study

Background

Sodium-glucose cotransporter-2 inhibitors reduce blood pressure (BP) and renal and cardiovascular events in patients with type 2 diabetes through not fully elucidated mechanisms. Aim of this study was to investigate whether dapagliflozin is able to acutely modify systemic and renal vascular function, as well as putative mechanisms.

Methods

Neuro-hormonal and vascular variables, together with 24 h diuresis, urinary sodium, glucose, isoprostanes and free-water clearance were assessed before and after a 2-day treatment with dapagliflozin 10 mg QD in sixteen type 2 diabetic patients; data were compared with those obtained in ten patients treated with hydrochlorothiazide 12.5 mg QD. Brachial artery endothelium-dependent and independent vasodilation (by flow-mediated dilation) and pulse wave velocity were assessed. Renal resistive index was obtained at rest and after glyceryl trinitrate administration. Differences were analysed by repeated measures ANOVA, considering treatment as between factor and time as within factor; Bonferroni post hoc comparison test was also used.

Results

Dapagliflozin decreased systolic BP and induced an increase in 24 h diuresis to a similar extent of hydrochlorothiazide; 24 h urinary glucose and serum magnesium were also increased. 24 h urinary sodium and fasting blood glucose were unchanged. Oxidative stress was reduced, as by a decline in urinary isoprostanes. Flow-mediated dilation was significantly increased (2.8 ± 2.2 to 4.0 ± 2.1%, p < 0.05), and pulse-wave-velocity was reduced (10.1 ± 1.6 to 8.9 ± 1.6 m/s, p < 0.05), even after correction for mean BP. Renal resistive index was reduced (0.62 ± 0.04 to 0.59 ± 0.05, p < 0.05). These vascular modifications were not observed in hydrochlorothiazide-treated individuals.

Conclusions

An acute treatment with dapagliflozin significantly improves systemic endothelial function, arterial stiffness and renal resistive index; this effect is independent of changes in BP and occurs in the presence of stable natriuresis, suggesting a fast, direct beneficial effect on the vasculature, possibly mediated by oxidative stress reduction.

Rationale, Design, and Baseline Characteristics of the Utopia Trial for Preventing Diabetic Atherosclerosis Using an SGLT2 Inhibitor: A Prospective, Randomized, Open-Label, Parallel-Group Comparative Study

INTRODUCTION

Sodium-glucose co-transporter-2 (SGLT2) inhibitors are anti-diabetic agents that improve glycemic control with a low risk of hypoglycemia and ameliorate a variety of cardiovascular risk factors. The aim of the ongoing study described herein is to investigate the preventive effects of tofogliflozin, a potent and selective SGLT2 inhibitor, on the progression of atherosclerosis in subjects with type 2 diabetes (T2DM) using carotid intima-media thickness (IMT), an established marker of cardiovascular disease (CVD), as a marker.

METHODS

The Study of Using Tofogliflozin for Possible better Intervention against Atherosclerosis for type 2 diabetes patients (UTOPIA) trial is a prospective, randomized, open-label, blinded-endpoint, multicenter, and parallel-group comparative study. The aim was to recruit a total of 340 subjects with T2DM but no history of apparent CVD at 24 clinical sites and randomly allocate these to a tofogliflozin treatment group or a conventional treatment group using drugs other than SGLT2 inhibitors. As primary outcomes, changes in mean and maximum IMT of the common carotid artery during a 104-week treatment period will be measured by carotid echography. Secondary outcomes include changes in glycemic control, parameters related to β-cell function and diabetic nephropathy, the occurrence of CVD and adverse events, and biochemical measurements reflecting vascular function.

CONCLUSION

This is the first study to address the effects of SGLT2 inhibitors on the progression of carotid IMT in subjects with T2DM without a history of CVD. The results will be available in the very near future, and these findings are expected to provide clinical data that will be helpful in the prevention of diabetic atherosclerosis and subsequent CVD.

FUNDING

Kowa Co., Ltd.

CLINICAL TRIAL REGISTRATION

UMIN000017607.

Rationale and design of a multicenter placebo-controlled double-blind randomized trial to evaluate the effect of empagliflozin on endothelial function: the EMBLEM trial

BACKGROUND

Type 2 diabetes mellitus (T2DM) is characterized by systemic metabolic abnormalities and the development of micro- and macrovascular complications, resulting in a shortened life expectancy. A recent cardiovascular (CV) safety trial, the EMPA-REG OUTCOME trial, showed that empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, markedly reduced CV death and all-cause mortality and hospitalization for heart failure in patients with T2DM and established CV disease (CVD). SGLT2 inhibitors are known to not only decrease plasma glucose levels, but also favorably modulate a wide range of metabolic and hemodynamic disorders related to CV pathways. Although some experimental studies revealed a beneficial effect of SGLT2 inhibitors on atherosclerosis, there is a paucity of clinical data showing that they can slow the progression of atherosclerosis in patients with T2DM. Therefore, the EMBLEM trial was designed to investigate whether empagliflozin treatment can improve endothelial function, which plays a pivotal role in the pathogenesis of atherosclerosis, in patients with T2DM and established CVD.

METHODS

The EMBLEM trial is an ongoing, prospective, multicenter, placebo-controlled double-blind randomized, investigator-initiated clinical trial in Japan. A total of 110 participants with T2DM (HbA1c range 6.0-10.0%) and with established CVD will be randomized (1:1) to receive either empagliflozin 10 mg once daily or a placebo. The primary endpoint of the trial is change in the reactive hyperemia (RH)-peripheral arterial tonometry-derived RH index at 24 weeks from baseline. For comparison of treatment effects between the treatment groups, the baseline-adjusted means and their 95% confidence intervals will be estimated by analysis of covariance adjusted for the following allocation factors: HbA1c (<7.0 or ≥7.0%), age (<65 or ≥65 years), systolic blood pressure (<140 or ≥140 mmHg), and current smoking status (nonsmoker or smoker). Key secondary endpoints include the change from baseline for other vascular-related markers such as arterial stiffness, sympathetic nervous activity, and parameters of cardiac and renal function. Importantly, serious adverse effects independently on the causal relationship to the trial drugs and protocol will be also evaluated throughout the trial period.

DISCUSSION

EMBLEM is the first trial to assess the effect of empagliflozin on endothelial function in patients with T2DM and established CVD. Additionally, mechanisms associating empagliflozin-mediated actions with endothelial function and other CV markers will be evaluated. Thus, the trial is designed to elucidate potential mechanisms by which empagliflozin protects CV systems and improves CV outcomes. Trial registration Unique Trial Number, UMIN000024502 ( https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000028197 ).

Emerging roles of sodium-glucose cotransporter 2 inhibitors in cardiology

The ultimate goal of treatment in people with diabetes mellitus is to prevent development of cardiovascular (CV) disease, resulting in prolongation of healthy life expectancy. Although impaired glycemic metabolism has a central role in its pathology, a number of studies have demonstrated that remedy for its imbalance cannot necessarily be accomplished as a therapeutic goal. A comprehensive medical approach against multi-factorial pathologies in diabetes, such as insulin resistance, obesity, hypertension, and dyslipidemia, in addition to diet and exercise therapy should be rather performed in the routine clinical setting. Along with such conceptual transition, what is required in anti-diabetes agents has also changed, and several anti-diabetes agents have been newly placed on the market in this decade. Such agents are required to undergo global pre- or post-marketing clinical trials assessing CV safety. A growing body of clinical evidence from those trials is now accumulating, and empagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, has first demonstrated significant risk reduction, relative to placebo, in CV death, overall mortality, and hospitalization for worsened heart failure in high-risk patients with diabetes mellitus. An SGLT2 inhibitor is a unique glucose-lowering agent and at the same time has multifaceted effects on hemodynamic and metabolic parameters beyond glycemic control. A major mode of action of SGLT2 inhibitors appears to be 'glycosuria' and 'natriuresis,' leading to amelioration of systemic glycemic homeostasis and potential cardio-renal protection. However, the precise mechanisms by which SGLT2 inhibitors affect benefits on the CV systems are yet to be fully elucidated. Thus, although we are now facing several unanswered concerns lurking behind the successful trial, SGLT2 inhibitors surely play several important roles in high-quality management of not only diabetes, but also CV medicine. This review summarizes our current understandings and future perspectives of SGLT2 inhibitors in CV medicine.