Impact of glucose-lowering drugs on cardiovascular disease in type 2 diabetes

Association of glucose-lowering medications with cardiovascular outcomes: an umbrella review and evidence map

BACKGROUND

Considering the global burden of diabetes and associated cardiovascular disease, an urgent need exists for the best treatment, which should be based on the best available evidence. We examined the association between glucose-lowering medications and a broad range of cardiovascular outcomes, and assessed the strength of evidence for these associations.

METHODS

For this umbrella review we searched PubMed, Embase, and the Cochrane Library to identify systematic reviews and meta-analyses of randomised controlled trials examining the cardiovascular safety of glucose-lowering medications. Cardiovascular outcomes examined included major adverse cardiovascular events, cardiovascular death, myocardial infarction, stroke, heart failure, unstable angina, and atrial fibrillation. For each meta-analysis, we estimated the relative risk (RR) and 95% CI. We also created an evidence map showing the plausible benefits or harms of each intervention and the certainty of the evidence.

FINDINGS

We examined 232 meta-analyses evaluating ten classes of diabetes drugs. We identified six risk and 38 protective associations showing a high strength of evidence. Six associations increased the risk of cardiovascular disease, including glimepiride (stroke [RR 2·01; 95% CI 1·02-3·98]), rosiglitazone (myocardial infarction [1·28; 1·02-1·62] and heart failure [1·72, 1·31-2·27]), and pioglitazone (heart failure [1·40; 1·16-1·69]). 38 associations decreased the risk of cardiovascular disease, including glucagon-like peptide-1 receptor agonists as a class (major adverse cardiovascular events [RR 0·88; 95% CI 0·84-0·92], death from cardiovascular disease [0·87; 0·81-0·94], myocardial infarction [0·92; 0·86-0·99], stroke [0·84; 0·77-0·93], and heart failure [0·90; 0·83-0·99]), albiglutide (major adverse cardiovascular events [0·81; 0·68-0·96], myocardial infarction [0·77; 0·64-0·92], and heart failure [0·71; 0·55-0·93]), dulaglutide (stroke [0·78; 0·64-0·96]), exenatide (major adverse cardiovascular events [0·91; 0·83-1·00]), liraglutide (major adverse cardiovascular events [0·86; 0·77-0·96]), semaglutide (major adverse cardiovascular events [0·76; 0·62-0·92] and stroke [0·67; 0·45-1·00]), sodium-glucose co-transporter-2 inhibitors as a class (major adverse cardiovascular events [0·87; 0·82-0·93], death from cardiovascular disease [0·82; 0·75-0·90], myocardial infarction [0·86; 0·78-0·94], and heart failure [0·68; 0·63-0·73]), canagliflozin (major adverse cardiovascular events [0·84; 0·75-0·93], death from cardiovascular disease [0·82; 0·71-0·96], and heart failure [0·65; 0·54-0·78]), dapagliflozin (heart failure [0·70; 0·60-0·82]), empagliflozin (major adverse cardiovascular events [0·85; 0·77-0·94], death from cardiovascular disease [0·62; 0·50-0·78], and heart failure [0·64; 0·53-0·77]), and pioglitazone (major adverse cardiovascular events [0·84; 0·74-0·96], myocardial infarction [0·80; 0·67-0·95], and stroke [0·79; 0·65-0·95]).

INTERPRETATION

We found varied levels of evidence for the associations between diabetes drugs and cardiovascular outcomes; some drugs raised the risk of cardiovascular disease, whereas others showed benefit.

FUNDING

None.

Dose distribution and up-titration patterns of metformin monotherapy in patients with type 2 diabetes

AIMS

To assess the dose distribution among users of metformin monotherapy as well as the patterns of up-titration following initiation of therapy in people with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This was a retrospective cohort study of adults with T2DM in the United Kingdom (UK). Metformin dose distribution was assessed at 0, 6 and 12 months in people initiating metformin monotherapy (new users) and cross-sectionally in people with ongoing metformin monotherapy (prevalent users). Patterns and predictors of up-titration were also analysed in new users. Dose distributions and treatment patterns were assessed descriptively; predictors of up-titration were determined using multivariable logistic regressions.

RESULTS

Totals of 6174 new users and 8733 prevalent users were included. New users initiated metformin at >0 mg to ≤500 mg (25%), >500 mg to ≤1000 mg (47%), >1000 mg to ≤1500 mg (17%) or >1500 mg to ≤2000 mg (12%) daily. This distribution did not vary over time. Prevalent users of metformin received doses of >0 mg to ≤500 mg (14%), >500 mg to ≤1000 mg (40%), >1000 mg to ≤1500 mg (15%), >1500 mg to ≤2000 mg (29%) or >2000 mg (1%) daily. Among new users of metformin, 6.7% and 10.8% had been up-titrated at 6 and 12 months, respectively, despite the majority having glycated haemoglobin >53 mmol/mol. Predictors of up-titration included younger age and higher HbA1c.

CONCLUSIONS

A majority of T2DM patients taking metformin received a dose ≤1000 mg/day. Up-titration of metformin is infrequent in the first year postinitiation.

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

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

Cardioprotective anti-hyperglycaemic medications: a review of clinical trials

Despite extensive clinical efforts to achieve stricter glycaemic control over the past few decades, cardiovascular (CV) disease remains the leading cause of death among diabetic patients. Recently, sodium-glucose cotransporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 receptor (GLP-1-R) agonists have gained attention due to their apparent effects in reducing CV mortality. Four CV randomized controlled trials: EMPA-REG, CANVAS, LEADER, and SUSTAIN-6, found a decrease in CV events among patients with type 2 diabetes on empagliflozin, canagliflozin, liraglutide, and semaglutide, respectively. In light of this data, the US Food and Drug Administration has recently approved empagliflozin for CV mortality reduction in type 2 diabetic patients, making it the first diabetes medication approved for such an indication. The purpose of this review is to summarize the results of novel anti-hyperglycaemic medication trials, and shed light on their mode of action and cardioprotective pathways.

Effect of Diabetes Mellitus on Complication Rates of Coronary Artery Bypass Grafting

Previous studies have shown that diabetes mellitus (DM) is a risk factor for postoperative coronary artery bypass grafting (CABG) complications. More contemporary studies are needed to guide revascularization decisions in DM patients. We performed a single-center study of patients who underwent CABG. Patients with no DM were compared with patients with DM, subgrouped according to whether or not DM was treated with insulin before admission (Insulin and No Insulin Groups). Multivariable logistic regression was used to determine whether DM was a significant predictor of mortality, combined postoperative events, and specific postoperative complications after controlling for other predictive clinical variables. Of 11,590 consecutive patients who underwent CABG, 5,013 (43%) had DM and 6,577 (57%) had no DM. Of the patients with DM, 3,433 (68%) were not treated with insulin and 1,580 (32%) were treated with insulin before admission. Multivariable logistic regression analyses showed that DM was not significantly associated with in-hospital mortality or combined postoperative events after considering other clinical variables. The No Insulin Group was significantly associated with stroke, and the Insulin Group was significantly associated with surgical site infection and new renal failure. In conclusion, this study of consecutively treated CABG patients shows that DM is not a predictor of in-hospital mortality or combined in-hospital postoperative events after adjusting for other clinical factors. DM is a predictor of permanent stroke, surgical site infection, and new renal failure. These findings may help with case selection and management of DM patients undergoing CABG.

Diabetes attenuated age-related aortic root dilatation in end-stage renal disease patients receiving peritoneal dialysis

AIMS/INTRODUCTION

Recently, some data have supported the concept that diabetes is negatively associated with aortic aneurysm. In the present study, we aimed to investigate the relationship between diabetes and cardiac structural and functional characteristics, in particular, aortic root dimensions, in end-stage renal disease (ESRD) patients.

METHODS

ESRD patients receiving peritoneal dialysis for >3 months were consecutively enrolled. Clinical features and echocardiographic parameters were analyzed according to the presence of diabetes history. Correlation analyses were carried out for diabetes mellitus and aortic root dilatation. Multiple logistic regression analysis was carried out to identify variables correlated with aortic root dilatation.

RESULTS

A total of 218 ESRD patients receiving peritoneal dialysis were enrolled. Patients with diabetes showed lower left ventricular internal measurements in end-diastole, left ventricular internal measurements in end-systole and aortic root diameter (ARD)/body surface area (BSA). Worse cardiac diastolic function was also observed in these patients. In addition, the age-related increase of ARD/BSA and ARD/height was attenuated in patients with diabetes. With the increase of ARD/BSA, lower levels of serum creatinine, phosphorus and serum glucose, as well as higher serum high-density lipoprotein cholesterol and apolipoprotein A-1 were also observed. Increased normalized left ventricular internal measurements were shown in patients with greater ARD/BSA. Multiple regression analysis showed that diabetes (odds ratio 0.353, P = 0.015) was an independent correlate of aortic root dilatation, even after correction for age, sex and other clinical confounders in the enrolled patients.

CONCLUSIONS

The present findings shown an inverse association between diabetes and age-related aortic root dilatation in ESRD patients. Diabetes remained to be independently correlated with aortic root dilatation even after adjustment for age, sex and other clinical confounders in ESRD patients.

Community-based management of complex type 2 diabetes: adaptation of an integrated model of care in a general practice setting

BACKGROUND

Overburdened hospital clinics can have adverse outcomes.

AIMS

To evaluate the effectiveness and patient acceptability of an integrated model of complex type 2 diabetes care delivered in a community-based general practice by upskilled general practitioners (GP) co-located with an endocrinologist and diabetes nurse educator.

METHODS

Patients transferred from hospital clinic lists or referred by local GP were assessed in two southern Perth practices. An upskilled GP and endocrinologist developed a management plan which was communicated to the participant's usual GP. Up to two follow-up visits over 6 months ensured that management was acceptable and effective.

RESULTS

A total of 464 people with type 2 diabetes (mean ± standard deviation age = 59.3 ± 13.7 years, 52.2% males) was enrolled. Their mean glycated haemoglobin (HbA_1c ) was 9.3% (78 mmol/mol) and their mean body mass index 33.7 kg/m² . Use of injectable blood glucose-lowering therapies increased between the initial and final visit in association with a median HbA_1c reduction of 1.2% (13 mmol/mol) which was sustained to 12 months in assessable participants. There were also reductions in blood pressure, and serum low-density lipoprotein cholesterol and triglyceride concentrations. Patient satisfaction with current treatment, time for self-management, time spent in diabetes-related appointments and diabetes knowledge increased significantly. Non-attendance for scheduled appointments was <10%. Local hospital referrals and waiting lists reduced over the study period.

CONCLUSIONS

This study confirms the value of integrated community-based care of complex type 2 diabetes which could represent a sustainable solution to overburdened hospital diabetes outpatient clinics.

Mediators of the Effects of Canagliflozin on Heart Failure in Patients With Type 2 Diabetes

OBJECTIVES

The purpose of this study was to explore potential mediators of the effects of canagliflozin on heart failure in the CANVAS Program (CANagliflozin cardioVascular Assessment Study; NCT01032629 and CANagliflozin cardioVascular Assessment Study-Renal; NCT01989754).

BACKGROUND

Canagliflozin reduced the risk of heart failure among patients with type 2 diabetes in the CANVAS Program. The mechanism of protection is uncertain.

METHODS

The percentages of mediating effects of 19 biomarkers were determined by comparing the hazard ratios for the effect of randomized treatment from an unadjusted model and from a model adjusting for the biomarker of interest. Multivariable analyses were used to assess the joint effects of biomarkers that mediated most strongly in univariable analyses.

RESULTS

Early changes after randomization in levels of 3 biomarkers (urinary albumin:creatinine ratio, serum bicarbonate, and serum urate) were identified as mediating the effect of canagliflozin on heart failure. Average post-randomization levels of 14 biomarkers (systolic blood pressure, low-density lipoprotein and high-density lipoprotein cholesterol, total cholesterol, urinary albumin:creatinine ratio, weight, body mass index, gamma glutamyltransferase, hematocrit, hemoglobin concentration, serum albumin, erythrocyte concentration, serum bicarbonate, and serum urate) were identified as significant mediators. Individually, the 3 biomarkers with the largest mediating effect were erythrocyte concentration (45%), hemoglobin concentration (43%), and serum urate (40%). In a parsimonious multivariable model, erythrocyte concentration, serum urate, and urinary albumin:creatinine ratio were the 3 biomarkers that maximized cumulative mediation (102%).

CONCLUSIONS

A diverse set of potential mediators of the effect of canagliflozin on heart failure were identified. Some mediating effects were anticipated, whereas others were not. The mediators that were identified support existing and novel hypothesized mechanisms for the prevention of heart failure with sodium glucose cotransporter 2 inhibitors.

Metformin therapy in patients with diabetes mellitus is associated with a reduced risk of vasculopathy and cardiovascular mortality after heart transplantation

Background

Cardiac allograft vasculopathy (CAV) is a major cause of morbidity and mortality following heart transplantation (HT). Reduced cardiovascular mortality and morbidity have been reported in non-HT patients treated with metformin. Given the high prevalence of type 2 diabetes mellitus (T2DM) in HT patients, we investigated the association between metformin therapy and cardiovascular outcomes after HT.

Methods

The study population comprised 103 DM patients who had undergone HT between 1994 and 2018 and were prospectively followed-up. We excluded from the study patients with type 1 diabetes mellitus. Fifty-five HT patients (53%) in the cohort were treated with metformin. Clinical data were recorded on prospectively designed forms. The primary outcomes included CAV, survival, and the combined end-point of CAV or cardiovascular mortality.

Results

Kaplan–Meier survival analysis showed that the CAV rate at 20 years of follow-up was lower in DM patients treated with metformin than in those who were not (30 vs. 65%; log-rank p = 0.044). Similarly, the combined risk of CAV or cardiovascular mortality was lower in the metformin-treated patients than in those not receiving metformin (32 vs. 68%; log rank p = 0.01). Consistently, multivariate analysis adjusted for age and comorbidities showed that metformin therapy was independently associated with a significant 90% reduction (95% confidence interval 0.02–0.46, p = 0.003) in the risk for the development of CAV, and a 91% reduction (95% confidence interval 0.02–0.42; p = 0.003) in the risk for CAV or cardiovascular mortality.

Conclusions

In diabetic HT patients, metformin therapy is independently associated with a significant reduction in the long-term risk for CAV and the combined end-point of CAV or cardiovascular mortality after HT.

[Antihyperglycemic treatment guidelines for diabetes mellitus type 2 (Update 2019)]

Hyperglycemia significantly contributes to complications in patients with diabetes mellitus. While lifestyle interventions remain cornerstones of disease prevention and treatment, most patients with type 2 diabetes will eventually require pharmacotherapy for glycemic control. The definition of individual targets regarding optimal therapeutic efficacy and safety as well as cardiovascular effects is of great importance. In this guideline we present the most current evidence-based best clinical practice data for healthcare professionals.

Can metformin stabilize PCSK9 level in stable coronary artery disease patients treated with statins?

Introduction

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as an important marker of cardiovascular risk and a new target for therapeutic interventions. We aimed to study the influence of metformin on the level of circulating PCSK9 in patients with stable coronary artery disease (SCAD) and type 2 diabetes (T2DM) or metabolic syndrome (MetS), receiving moderate doses of statins used in routine clinical practice.

Material and methods

The study included 80 patients with T2DM or MetS receiving rosuvastatin for at least three months prior the study. MetS was diagnosed based on the Global Consensus Definition of the International Diabetes Federation (IDF). Serum level of PCSK9 was measured with an ELISA kit.

Results

Patients with T2DM or MetS, who took part in the research, were divided into 2 groups - those who received metformin prior the main study (21 patients - 1^st group) and patients who did not (59 patients - 2^nd group). Addition of metformin to the 3-month statin therapy of the 2nd group patients, divided into subgroup A (n = 27) with the addition of metformin and subgroup B (n = 29) without one, did not significantly affect the level of lipids. However, the level of circulating PCSK9 in subgroup A patients decreased, compared to subgroup B (p < 0.01). At the same time, ongoing metformin and rosuvastatin therapy in the 1^st group patients was not accompanied by a further decrease of the PCSK9 level.

Conclusions

The addition of metformin to ongoing rosuvastatin therapy did not significantly affect serum lipid levels, but stabilized the level of circulating PCSK9, compared with the group without metformin treatment.

Cardiovascular outcome trials of the newer anti-diabetic medications

Concerns of elevated cardiovascular disease (CVD) risk with some anti-diabetic medications warranted phase 4 clinical trials to demonstrate CVD safety of newly marketed anti-diabetic drugs. Although initially designed to evaluate safety, some of these CVD outcome trials (CVOTs) have in fact shown CVD benefits. New medication classes, like glucagon-like peptide 1 (GLP-1) analogues and sodium-glucose co-transporter 2 (SGLT2) inhibitors, have shown reductions in the risk of major adverse cardiovascular events (MACE) including, myocardial infarction, stroke, CV death, and heart failure (HF). Perhaps more importantly, SGLT2 inhibitors demonstrated reduction in the risk of HF hospitalizations, being the first class of anti-diabetic drugs to do so. Conversely, dipeptidyl peptidase 4 (DPP-4) inhibitors did not significantly affect atherosclerotic CVD end-points and some actually increased the risk of HF hospitalizations. Further, the adverse/beneficial CVD effects of these medications may not be class specific. This review focuses on the main results of these CVOTs while highlighting the heterogeneity of CVD end-points within each class and discusses important mechanistic insights and adverse effect profiles.

Identification of a Novel Scaffold for Inhibition of Dipeptidyl Peptidase-4

Dipeptidyl peptidase-4 (DPP-4) is considered a major drug target for type 2 diabetes mellitus (T2DM). In addition to T2DM, a regulatory role of DPP-4 was also found in cardiovascular diseases. Existing DPP-4 inhibitors have been reported to have several adverse effects. In this study, a computer-aided drug design approach and its use to detect a novel class of inhibitor for DPP-4 are reported. Through structure and pharmacophore-based screening, we identified 13 hit compounds from an ∼4-million-compound library. Physical interactions of these hits with DPP-4 were studied using docking and explicit solvent molecular dynamics (MD) simulations. Later, MMPBSA binding energy was calculated for the ligand/protein simulation trajectories to determine the stability of compounds in the binding cavity. These compounds have a novel scaffold and exhibited a stable binding mode. "Best-in-screen" compounds (or their closest available analogs) were resourced and their inhibition of DPP-4 activity was experimentally validated using an in vitro enzyme activity assay in the presence of 100 and 10 μM compounds. These assays identified a compound with a spirochromanone center with 53% inhibition activity at a 100 μM concentration. A further five spirochromanone compounds were synthesized and examined in silico and in vitro; again, one compound showed 53% inhibitory activity action at 100 μM. Overall, this study identified two novel "spirochromanone" compounds that lowered DPP-4 activity by more than ∼50% at 100 μM. This study also showed the impact of fast in silico drug design techniques utilizing virtual screening and MD to identify novel scaffolds to bind and inhibit DPP-4. Spirochromanone motif identified here may be used to design molecules to achieve drug-like inhibitory action against DPP-4.

Moderate weight change following diabetes diagnosis and 10 year incidence of cardiovascular disease and mortality

AIMS/HYPOTHESIS

Adults with type 2 diabetes are at high risk of developing cardiovascular disease (CVD). Evidence of the impact of weight loss on incidence of CVD events among adults with diabetes is sparse and conflicting. We assessed weight change in the year following diabetes diagnosis and estimated associations with 10 year incidence of CVD events and all-cause mortality.

METHODS

In a cohort analysis among 725 adults with screen-detected diabetes enrolled in the Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION)-Cambridge trial, we estimated HRs for weight change in the year following diabetes diagnosis and 10 year incidence of CVD (n = 99) and all-cause mortality (n = 95) using Cox proportional hazards regression. We used linear regression to estimate associations between weight loss and CVD risk factors. Models were adjusted for age, sex, baseline BMI, smoking, occupational socioeconomic status, cardio-protective medication use and treatment group.

RESULTS

Loss of ≥5% body weight in the year following diabetes diagnosis was associated with improvements in HbA_1c and blood lipids and a lower hazard of CVD at 10 years compared with maintaining weight (HR 0.52 [95% CI 0.32, 0.86]). The associations between weight gain vs weight maintenance and CVD (HR 0.41 [95% CI 0.15, 1.11]) and mortality (HR 1.63 [95% CI 0.83, 3.19]) were less clear.

CONCLUSIONS/INTERPRETATION

Among adults with screen-detected diabetes, loss of ≥5% body weight during the year after diagnosis was associated with a lower hazard of CVD events compared with maintaining weight. These results support the hypothesis that moderate weight loss may yield substantial long-term CVD reduction, and may be an achievable target outside of specialist-led behavioural treatment programmes.

Navigating the "MACE" in Cardiovascular Outcomes Trials and decoding the relevance of Atherosclerotic Cardiovascular Disease benefits versus Heart Failure benefits

The publication of results from recent cardiovascular outcome trials (CVOTs) has transformed the landscape of diabetes treatment. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium glucose co-transporter-2 (SGLT2) inhibitors have demonstrated CV benefits in large, well-conducted, randomized studies. Today, empagliflozin, canagliflozin and liraglutide are US Food and Drug Administration-approved not only for glucose-lowering, but also to reduce the risk of cardiovascular (CV) events/CV mortality in people with type 2 diabetes (T2DM) and established CV disease (CVD)/high CVD risk. Although the CVOTs were primarily powered for CV safety (non-inferiority), they also demonstrated CV efficacy (superiority). This initially surprised many in the diabetes community, but the replication of the CV benefits with different compounds in the same class alleviated concerns about the CV benefits being chance findings. However, many questions remain. While the heterogeneity in the CV benefits in the various CVOTs can be attributed to the variability in CV risk in the different studies, the reason(s) for the differences in the CV benefits between the GLP-1RA class and the SGLT2 inhibitor class appear to be more complex. An analysis of major adverse cardiovascular events (MACE) in the CVOTs shows that the CV benefits of GLP-1RAs are predominantly specific to atherosclerotic CV events (non-fatal myocardial infarction [MI], non-fatal stroke and CV death). By contrast, the SGLT2 inhibitors do not have any significant effects on atherosclerotic CV events (non-fatal MI/stroke). Their benefits are predominantly on hospitalization for heart failure (HF), suggesting effects primarily on myocardial function ("the pump"), and not on the "pipes" (coronary arteries). In the present review, we discuss the rationale for the conduct of CVOTs, highlight the inability of the classic three-point MACE to capture the entire spectrum of atherosclerotic and non-atherosclerotic CVD morbidity, especially HF in T2DM, and discuss the results of the CVOTs with a focus on the clinical significance of atherosclerotic CVD (ASCVD) versus HF, which develops in a sizeable proportion of people with diabetes and without prior ASCVD.

Dapagliflozin: A Review in Type 2 Diabetes

Dapagliflozin (Forxiga®) is a highly potent, reversible and selective sodium-glucose cotransporter-2 inhibitor indicated worldwide for the treatment of type 2 diabetes (T2D). In the EU, oral dapagliflozin once daily is approved for use as monotherapy (in patients who are intolerant of metformin) and as add-on combination therapy (with other glucose-lowering agents, including insulin) for T2D when diet and exercise alone do not provide adequate glycaemic control. In numerous well-designed clinical studies and their extensions, dapagliflozin as monotherapy and combination therapy with other antihyperglycaemic agents provided effective glycaemic control and reduced bodyweight and blood pressure (BP) across a broad spectrum of patients. Dapagliflozin reduced the rate of cardiovascular (CV) death or hospitalization for heart failure (HHF), did not adversely affect major adverse CV events (MACE) and possibly reduced progression of renal disease relative to placebo in patients with established atherosclerotic CV disease (CVD) or multiple risk factors for CVD. Dapagliflozin was generally well tolerated, with a low risk of hypoglycaemia; diabetic ketoacidosis (DKA), although rare, and genital infections were more common with dapagliflozin than placebo. Given its antihyperglycaemic, cardioprotective and possibly renoprotective properties and generally favourable tolerability profile, dapagliflozin provides an important option for the management of a broad patient population, regardless of the history of CVD.

Cardiovascular Protection with Anti-hyperglycemic Agents

Diabetes mellitus is a major risk factor for cardiovascular (CV) disease. Conversely, CV disease is responsible for a majority of the deaths in patients with diabetes. Many drug trials have concentrated on blood glucose (hemoglobin A_1c) reduction. This strategy, while reducing microvascular outcomes like nephropathy and neuropathy, has little or no effect on reducing macrovascular events like heart attack, stroke, and heart failure. It has been postulated that hypoglycemia may counterbalance some of the beneficial effects of anti-hyperglycemic agents, but this is not proven. Further, trial evidence for thiazolidinediones (rosiglitazone and pioglitazone) showed increased risk of heart failure and raised concerns about increased myocardial infarction. This heightened awareness of potentially harmful CV effects of otherwise effective hypoglycemic drugs resulted in regulatory mandates for CV outcome trials to ascertain the safety of newer anti-hypoglycemic agents appearing on the market. Three new classes of anti-hyperglycemic agents have been introduced in recent years. While dipeptidyl peptidase-4 (DPP-4) inhibitors exhibited increased heart failure hospitalization in the SAVOR-TIMI 53 trial evaluating saxagliptin and in the secondary analysis of the EXAMINE trial for alogliptin, the effects of glucagon-like peptide-1 (GLP-1) analogs and sodium-glucose co-transporter-2 (SGLT2) inhibitors on CV outcomes in diabetes have largely been positive. The LEADER and SUSTAIN-6 trials evaluating the safety and efficacy of the GLP-1 analogs liraglutide and semaglutide, respectively, showed a statistically significant reduction in the primary outcome (major adverse cardiac events [MACE]: CV death, myocardial infarction, and stroke) and the secondary combined outcome when compared to placebo. Results of the TECOS trial for sitagliptin were, however, neutral (no net CV benefit or harm), questioning the class effect of GLP-1 analogs. Results of the SGLT2 inhibitor trials were more uniform. While EMPA-REG (evaluating empagliflozin) and CANVAS (evaluating canagliflozin) showed a reduction in the MACE end point, dapagliflozin had a net neutral effect on MACE in DECLARE-TIMI 58. All three SGLT2 inhibitors, however, showed a significant reduction in heart failure hospitalizations. Although initially designed to keep potentially harmful anti-hyperglycemic agents off the market, the CV outcome trials have provided clinicians with a new set of anti-hyperglycemic drugs with proven CV benefit in patients with diabetes and CV disease, thus expanding the field of CV secondary prevention. There is a need to inculcate GLP-1 analogs and SGLT2 inhibitors that reduce major CV events and heart failure hospitalizations (alongside lifestyle management and metformin) in the treatment of patients with diabetes and CV disease.

Cardiovascular efficacy and safety of sodium-glucose co-transporter-2 inhibitors and glucagon-like peptide-1 receptor agonists: a systematic review and network meta-analysis

AIMS

To compare the cardiovascular efficacy and safety of sodium-glucose co-transporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RAs) in adults with Type 2 diabetes.

METHODS

Electronic databases were searched from inception to 22 October 2018 for randomized controlled trials designed to assess the cardiovascular efficacy of SGLT2 inhibitors or GLP-1RAs with regard to a three-point composite measure of major adverse cardiovascular events (non-fatal stroke, non-fatal myocardial infarction and cardiovascular mortality). Cardiovascular and safety data were synthesized using Bayesian network meta-analyses.

RESULTS

Eight trials, including 60 082 participants, were deemed eligible for the network meta-analysis. Both SGLT2 inhibitors [hazard ratio 0.86 (95% credible interval 0.74, 1.01]) and GLP-1RAs [hazard ratio 0.88 (95% credible interval 0.78, 0.98)] reduced the three-point composite measure compared to placebo, with no evidence of differences between them [GLP-1RAs vs SGLT2 inhibitors: hazard ratio 1.02 (95% credible interval 0.83, 1.23)]. SGLT2 inhibitors reduced risk of hospital admission for heart failure compared to placebo [hazard ratio 0.67 (95% credible interval 0.53, 0.85)] and GLP-1RAs [hazard ratio 0.71 (95% credible interval 0.53, 0.93)]. No differences were found between the two drug classes in non-fatal stroke, non-fatal myocardial infarction, cardiovascular mortality, all-cause mortality or safety outcomes.

CONCLUSIONS

SGLT2 inhibitors and GLP-1RAs reduced the three-point major adverse cardiovascular event risk compared to placebo, with no differences between them. Compared with GLP-1RAs and placebo, SGLT2 inhibitors led to a larger reduction in hospital admission for heart failure risk.

GLP-1-based therapies to boost autophagy in cardiometabolic patients: From experimental evidence to clinical trials

Obesity has many deleterious effects on the cardiovascular system, mediated by changes in insulin sensitivity, dyslipidaemia, oxidative stress and inflammation. Current therapies mainly focus on caloric intake suppression and bariatric surgery, however the efficacy of these approaches remains elusive as most patients regain their body weight within the next 5 years. A better understanding of the pathophysiology of obesity is of paramount importance for the development of new therapeutic strategies to prevent vascular complications. Autophagy has emerged as key self-degrading process responsible for the maintenance of cellular homeostasis. Defects in autophagy homeostasis are implicated in metabolic disorders, including obesity, insulin resistance, diabetes mellitus and atherosclerosis. Most importantly, autophagy regulates animal lifespan. Albeit ample preclinical evidence supports the therapeutic promise of autophagy modulators for the treatment of obesity and metabolic diseases, the clinical efficacy of pharmacological modulation of autophagy remains to be proven. Recent work has shown that GLP-1-based therapeutic approaches may positively affect autophagy in perivascular adipose tissue, thus improving obesity-related endothelial dysfunction. In the present review we discuss current evidence on the role of autophagy in obesity, with a specific focus on DPP-4 inhibitors (DPP-4i) and GLP-1 receptor agonists (GLP-1 RA) as modulators of this process. Experimental evidence on GLP-1-based approaches is critically discussed in light of recent clinical trials with DPP-4i and GLP-1 RA.

Glucose Is Involved in the Dynamic Regulation of m6A in Patients With Type 2 Diabetes

CONTEXT

N6-methyladenosine (m6A) in mRNA is the most abundant and reversible modification. However, the mechanism behind the decrease in m6A in patients with type 2 diabetes (T2D) has not yet been thoroughly investigated.

OBJECTIVE

To clarify whether glucose is involved in the dynamic regulation of m6A in T2D and to identify a possible underlying mechanism.

METHODS

Liquid chromatography/electrospray ionization/tandem mass spectrometry and quantitative PCR were performed to determine the m6A content and the mRNA expression of target genes in 102 patients with T2D and 107 controls. An additional 12 patients with normal fasting blood glucose, emergency hyperglycemia, or emergency hypoglycemia, as well as HepG2 cells with high-glucose treatment and FTO knockout or overexpression were used to confirm the initial observations in patients.

RESULTS

In patients with T2D, the m6A content was decreased, and mRNA expression levels of FTO, METTL3, METTL14, and WTAP were increased. Interestingly, the m6A content was negatively associated with mRNA expression levels of METTL3, METTL14, and FTO. Moreover, FTO was positively correlated with serum glucose. In HepG2 cells, high glucose upregulated FTO protein, whereas it had no significant effect on METTL3 or METTL14. Additionally, mRNA expression levels of FOXO1, G6PC, and DGAT2 were significantly increased and positively correlated with FTO and serum glucose in patients.

CONCLUSIONS

Our data revealed that in patients with T2D, high-glucose-enhanced FTO mRNA expression resulted in a decrease in m6A. The lower m6A content might be responsible for the upregulation of methyltransferases. Additionally, FTO induced mRNA expression of FOXO1, G6PC, and DGAT2 and was closely associated with glucose metabolism.

The Standard of Care in Type 2 Diabetes: Re-evaluating the Treatment Paradigm

There is currently a worldwide epidemic of type 2 diabetes (T2D) that is predicted to increase substantially in the next few years. With 80% of the global T2D population living in low to middle-income countries, there are issues with cost and of access to appropriate medicines. The objective of this symposium was to provide an overview of the efficacy and safety of glucose-lowering drugs, focussing in particular on sulfonylureas (SUs) in patients with T2D using data taken from both randomised controlled trials (RCTs) and real-world studies, the application of strategies to ensure optimal patient adherence and clinical outcomes, and the optimal use of SUs in terms of dose adjustment and agent choice to ensure the best clinical outcome. The symposium began by exploring a profile of the typical patient seen in diabetes clinical practice and the appropriate management of such a patient in the real world, before moving on to an overview of the risks associated with T2D and how the currently available agents, including newer antidiabetic medications, mitigate or exacerbate those risks. The final presentation provided an overview of real-world studies, the gap between RCTs and the real world, and the use of available glucose-lowering agents in daily clinical practice. Clinical evidence was presented demonstrating that tight glucose control improved both microvascular and macrovascular outcomes, but that aggressive treatment in patients with a very high cardiovascular risk could lead to adverse outcomes. Real-world data suggest that older agents such as SUs and metformin are being used in a large proportion of patients with T2D with demonstrable effectiveness, indicating that they still have a place in modern T2D management. The symposium, while acknowledging the need for newer antidiabetic drugs in specific situations and patient groups, recommended the continuation of SUs and metformin as the primary oral antidiabetic agents in resource-constrained regions of the world.Funding:Servier.

Highly Selective and Potent Human β-Secretase 2 (BACE2) Inhibitors against Type 2 Diabetes: Design, Synthesis, X-ray Structure and Structure-Activity Relationship Studies

Herein we present the design, synthesis, and biological evaluation of potent and highly selective β-secretase 2 (memapsin 1, beta-site amyloid precursor protein cleaving enzyme 2, or BACE 2) inhibitors. BACE2 has been recognized as an exciting new target for type 2 diabetes. The X-ray structure of BACE1 bound to inhibitor 2 a {N³ -[(1S,2R)-1-benzyl-2-hydroxy-3-[[(1S,2S)-2-hydroxy-1-(isobutylcarbamoyl)propyl]amino]propyl]-5-[methyl(methylsulfonyl)amino]-N¹ -[(1R)-1-phenylpropyl]benzene-1,3-dicarboxamide} containing a hydroxyethylamine isostere was determined. Based on this structure, a computational docking study was performed which led to inhibitor 2 a-bound BACE2 models. These were used to optimize the potency and selectivity of inhibitors. A systematic structure-activity relationship study led to the identification of determinants of the inhibitors' potency and selectivity toward the BACE2 enzyme. Inhibitors 2 d [N³ -[(1S,2R)-1-benzyl-2-hydroxy-3-[[(1S,2S)-2-hydroxy-1-(isobutylcarbamoyl)pentyl]amino]propyl]-N¹ -methyl-N¹ -[(1R)-1-phenylpropyl]benzene-1,3-dicarboxamide; K_i =0.031 nm, selectivity over BACE1: ≈174 000-fold] and 3 l [N¹ -((2S,3R)-3-hydroxy-1-phenyl-4-((3-(trifluoromethyl)benzyl)amino)butan-2-yl)-N³ ,5-dimethyl-N³ -((R)-1-phenylethyl)isophthalamide; K_i =1.6 nm, selectivity over BACE1: >500-fold] displayed outstanding potency and selectivity. Inhibitor 3 l is nonpeptide in nature and may pave the way to the development of a new class of potent and selective BACE2 inhibitors with clinical potential.

Using probiotics for type 2 diabetes mellitus intervention: Advances, questions, and potential

Type 2 diabetes mellitus (T2DM) has become one of the most prevalent diseases on earth and several treatments have been developed. However, the current intervention approaches have not been as effective as expected. One promising supplementary strategy is the use of probiotics through direct or indirect approaches. Probiotics are microbial food cultures conferring health-promoting properties. In this review, we summarized the current theories and mechanisms of T2DM intervention using probiotics and hypothesize that probiotics intervene T2DM during its onsetting, developing, and complicating. For the first time, we comprehensively analyzed T2DM intervention in animal models using both wide-type probiotics in different forms and using recombinant probiotics. Then, probiotic intervention in T2DM patients was reviewed and the main results were compared with that obtained from animal studies. Finally yet importantly, remaining questions that are important such as in which form and in which state, as well as the future potential of probiotic intervention in T2DM were discussed from a perspective of food microbiologists. In conclusion, probiotic intervention in T2DM is promising but there are still many important issues unsolved yet. Critical review of the advances, questions, and potential of probiotic intervention in T2DM promotes the development of this approach for further application in humans.

ONS donor entwined iron(iii) and cobalt(iii) complexes with exemplary safety profile as potent anticancer and glucose uptake agents

Highly safe, efficacious iron(iii) and cobalt(iii) complexes are found to be effective in vitro anticancer and antidiabetic agents.

Trans-repression of NFκB pathway mediated by PPARγ improves vascular endothelium insulin resistance

Previous study has shown that thiazolidinediones (TZDs) improved endothelium insulin resistance (IR) induced by high glucose concentration (HG)/hyperglycaemia through a PPARγ‐dependent‐NFκB trans‐repression mechanism. However, it is unclear, whether changes in PPARγ expression affect the endothelium IR and what the underlying mechanism is. In the present study, we aimed to address this issue. HG‐treated human umbilical vascular endothelial cells (HUVEC) were transfected by either PPARγ‐overexpressing (Ad‐PPARγ) or PPARγ‐shRNA‐containing (Ad‐PPARγ‐shRNA) adenoviral vectors. Likewise, the rats fed by high‐fat diet (HFD) were infected by intravenous administration of Ad‐PPARγ or Ad‐PPARγ‐shRNA. The levels of nitric oxide (NO), endothelin‐1 (ET‐1) and cytokines (TNFα, IL‐6, sICAM‐1 and sVCAM‐1) and the expression levels of PPARγ, eNOS, AKT, p‐AKT, IKKα/β and p‐IKKα/β and IκBα were examined; and the interaction between PPARγ and NFκB‐P65 as well as vascular function were evaluated. Our present results showed that overexpression of PPARγ notably increased the levels of NO, eNOS, p‐AKT and IκBα as well as the interaction of PPARγ and NFκB‐P65, and decreased the levels of ET‐1, p‐IKKα/β, TNFα, IL‐6, sICAM‐1 and sVCAM‐1. In contrast, down‐expression of PPARγ displayed the opposite effects. The results demonstrate that the overexpression of PPARγ improves while the down‐expression worsens the endothelium IR via a PPARγ‐mediated NFκB trans‐repression dependent manner. The findings suggest PPARγ is a potential therapeutic target for diabetic vascular complications.

MANAGEMENT OF ENDOCRINE DISEASE: Critical review of the evidence underlying management of glucocorticoid-induced hyperglycaemia

Glucocorticoids are frequently prescribed to patients with a wide range of inflammatory and autoimmune diseases. The semi-synthetic glucocorticoid prednisolone is most commonly prescribed and in two main patterns. Prednisolone is prescribed short term at medium-high doses to treat an acute inflammatory illness or long term at lower doses to attenuate chronic inflammatory disease progression. In hospitalized patients with acute prednisolone-induced hyperglycaemia, there is a distinct circadian pattern of glucose elevation, which occurs predominantly in the afternoon and evening. As a morning dose of isophane insulin has a pharmacokinetic pattern that matches this pattern of glucose elevation, treatment comprising a basal dose of morning isophane insulin in combination with short-acting insulin boluses is generally recommended. However, evidence is lacking that isophane-based basal bolus insulin is more efficacious than other insulin regimens. In outpatients, low-dose prednisolone causes a small increase in post glucose-load glucose concentration but no change in overall glycaemic control as measured by glycosylated haemoglobin. If treatment is indicated, metformin has been shown to be effective and may attenuate other adverse effects of long-term prednisolone therapy. Further studies are necessary in order to identify factors underlying the variability in response to insulin therapy and clinical benefits of treatment in hospitalized patients with prednisolone-induced hyperglycaemia. In outpatients prescribed low-dose prednisolone, the cardiovascular risk associated with postprandial hyperglycaemia and efficacy of hypoglycaemic therapies should be evaluated in future randomized clinical trials.

Liraglutide Treatment Reduces Endothelial Endoplasmic Reticulum Stress and Insulin Resistance in Patients With Diabetes Mellitus

Background Prior studies have shown that nutrient excess induces endoplasmic reticulum ( ER ) stress in nonvascular tissues from patients with diabetes mellitus ( DM ). ER stress and the subsequent unfolded protein response may be protective, but sustained activation may drive vascular injury. Whether ER stress contributes to endothelial dysfunction in patients with DM remains unknown. Methods and Results To characterize vascular ER stress, we isolated endothelial cells from 42 patients with DM and 37 subjects without DM. Endothelial cells from patients with DM displayed higher levels of ER stress markers compared with controls without DM. Both the early adaptive response, evidenced by higher phosphorylated protein kinase-like ER eukaryotic initiation factor-2a kinase and inositol-requiring ER-to-nucleus signaling protein 1 ( P=0.02, P=0.007, respectively), and the chronic ER stress response evidenced by higher C/ EBP α-homologous protein ( P=0.02), were activated in patients with DM . Higher inositol-requiring ER-to-nucleus signaling protein 1 activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction ( r=0.53, P=0.02). Acute treatment with liraglutide, a glucagon-like peptide 1 receptor agonist, reduced p-inositol-requiring ER-to-nucleus signaling protein 1 ( P=0.01), and the activation of its downstream target c-jun N-terminal kinase ( P=0.025) in endothelial cells from patients with DM . Furthermore, liraglutide restored insulin-stimulated endothelial nitric oxide synthase activation in patients with DM ( P=0.019). Conclusions In summary, our data suggest that ER stress contributes to vascular insulin resistance and endothelial dysfunction in patients with DM . Further, we have demonstrated that liraglutide ameliorates ER stress, decreases c-jun N-terminal kinase activation and restores insulin-mediated endothelial nitric oxide synthase activation in endothelial cells from patients with DM .

Modern Sulfonylureas Strike Back - Exploring the Freedom of Flexibility

This editorial discusses the concept of flexibility in diabetes care. Flexibility of an oral antidiabetic drug (OAD) is defined as its ability to be used efficaciously and safely, in flexible, convenient doses and frequencies, at flexible timings of administration. This flexibility also includes OAD usage alone or in combination with a wide spectrum of drugs, in a wide spectrum of patients, irrespective of their age, gender, health status, or dietary patterns, with flexible dose titration, glucose monitoring and healthcare contact schedules. This editorial examines the flexibility of the modern sulfonylureas such as gliclazide extended (modified) release (MR) preparation in the management of diabetes. Using evidence-based rationale, we demonstrate that gliclazide MR is a flexible, and useful option for the management of type 2 diabetes.

Sodium-glucose cotransporter-2 inhibition for the reduction of cardiovascular events in high-risk patients with diabetes mellitus

Patients with type 2 diabetes mellitus (T2DM) exhibit an increased risk for cardiovascular (CV) events. Hyperglycemia itself contributes to the pathogenesis of atherosclerosis and heart failure (HF) in these patients, but glucose-lowering strategies studied to date have had little or no impact on reducing CV risk, especially in patients with a long duration of T2DM and prevalent CV disease (CVD). Sodium-glucose cotransporter-2 (SGLT2) inhibitors are the new class of glucose-lowering medications that increase urinary glucose excretion, thus improving glycemic control, independent of insulin. The recently published CV outcome trial, Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME), demonstrated that the SGLT2 inhibitor empagliflozin significantly reduced the combined CV end point of CV death, nonfatal myocardial infarction, and nonfatal stroke vs. placebo in a population of patients with T2DM and prevalent atherosclerotic CVD. In addition, and quite unexpectedly, empagliflozin significantly and robustly reduced the individual end points of CV death, overall mortality, and hospitalization for HF in this high-risk population. Several beneficial factors beyond glucose control, such as weight loss, lowering blood pressure, sodium depletion, renal hemodynamic effects, effects on myocardial energetics, and/or neurohormonal effects, have been seen with SGLT2 inhibition.

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.

Development of predictive risk models for major adverse cardiovascular events among patients with type 2 diabetes mellitus using health insurance claims data

Background

There exist several predictive risk models for cardiovascular disease (CVD), including some developed specifically for patients with type 2 diabetes mellitus (T2DM). However, the models developed for a diabetic population are based on information derived from medical records or laboratory results, which are not typically available to entities like payers or quality of care organizations. The objective of this study is to develop and validate models predicting the risk of cardiovascular events in patients with T2DM based on medical insurance claims data.

Methods

Patients with T2DM aged 50 years or older were identified from the Optum™ Integrated Real World Evidence Electronic Health Records and Claims de-identified database (10/01/2006–09/30/2016). Risk factors were assessed over a 12-month baseline period and cardiovascular events were monitored from the end of the baseline period until end of data availability, continuous enrollment, or death. Risk models were developed using logistic regressions separately for patients with and without prior CVD, and for each outcome: (1) major adverse cardiovascular events (MACE; i.e., non-fatal myocardial infarction, non-fatal stroke, CVD-related death); (2) any MACE, hospitalization for unstable angina, or hospitalization for congestive heart failure; (3) CVD-related death. Models were developed and validated on 70% and 30% of the sample, respectively. Model performance was assessed using C-statistics.

Results

A total of 181,619 patients were identified, including 136,544 (75.2%) without prior CVD and 45,075 (24.8%) with a history of CVD. Age, diabetes-related hospitalizations, prior CVD diagnoses and chronic pulmonary disease were the most important predictors across all models. C-statistics ranged from 0.70 to 0.81, indicating that the models performed well. The additional inclusion of risk factors derived from pharmacy claims (e.g., use of antihypertensive, and use of antihyperglycemic) or from medical records and laboratory measures (e.g., hemoglobin A1c, urine albumin to creatinine ratio) only marginally improved the performance of the models.

Conclusion

The claims-based models developed could reliably predict the risk of cardiovascular events in T2DM patients, without requiring pharmacy claims or laboratory measures. These models could be relevant for providers and payers and help implement approaches to prevent cardiovascular events in high-risk diabetic patients.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0759-z) contains supplementary material, which is available to authorized users.

Actions of metformin and statins on lipid and glucose metabolism and possible benefit of combination therapy

Patients with diabetes type 2 have an increased risk for cardiovascular disease and commonly use combination therapy consisting of the anti-diabetic drug metformin and a cholesterol-lowering statin. However, both drugs act on glucose and lipid metabolism which could lead to adverse effects when used in combination as compared to monotherapy. In this review, the proposed molecular mechanisms of action of statin and metformin therapy in patients with diabetes and dyslipidemia are critically assessed, and a hypothesis for mechanisms underlying interactions between these drugs in combination therapy is developed.

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

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

Metformin and AMP Kinase Activation Increase Expression of the Sterol Transporters ABCG5/8 (ATP-Binding Cassette Transporter G5/G8) With Potential Antiatherogenic Consequences

OBJECTIVE

The mechanisms underlying the cardiovascular benefit of the anti-diabetic drug metformin are poorly understood. Recent studies have suggested metformin may upregulate macrophage reverse cholesterol transport. The final steps of reverse cholesterol transport are mediated by the sterol transporters, ABCG5 (ATP-binding cassette transporter G5) and ABCG8 (ATP-binding cassette transporter G8), which facilitate hepato-biliary transport of cholesterol. This study was undertaken to assess the possibility that metformin induces Abcg5 and Abcg8 expression in liver and to elucidate the underlying mechanisms.

APPROACH AND RESULTS

Metformin-treated mouse or human primary hepatocytes showed increased expression of Abcg5/8 and the bile salt export pump, Bsep. Administration of metformin to Western-type diet-fed mice showed significant upregulation of Abcg5/8 and Bsep. This resulted in increased initial clearance of ³H-cholesteryl ester HDL (high-density lipoprotein) from plasma. However, fecal ³H-cholesterol output was only marginally increased, possibly reflecting increased hepatic Ldlr (low-density lipoprotein receptor) expression, which would increase nonradiolabeled cholesterol uptake. Abcg5/8 undergo strong circadian variation. Available chromatin immunoprecipitation-Seq data suggested multiple binding sites for Period 2, a transcriptional repressor, within the Abcg5/8 locus. Addition of AMPK (5' adenosine monophosphate-activated protein kinase) agonists decreased Period 2 occupancy, suggesting derepression of Abcg5/8. Inhibition of ATP citrate lyase, which generates acetyl-CoA from citrate, also decreased Period 2 occupancy, with concomitant upregulation of Abcg5/8. This suggests a mechanistic link between feeding-induced acetyl-CoA production and decreased cholesterol excretion via Period 2, resulting in inhibition of Abcg5/8 expression.

CONCLUSIONS

Our findings provide partial support for the concept that metformin may provide cardiovascular benefit via increased reverse cholesterol transport but also indicate increased Ldlr expression as a potential additional mechanism. AMPK activation or ATP citrate lyase inhibition may mediate antiatherogenic effects through increased ABCG5/8 expression.

The association study of high-sensitivity C-reactive protein, pentraxin 3, nitrotyrosine, and insulin dose in patients with insulin-treated type 2 diabetes mellitus

PURPOSE

The objective of this study was to examine the association between insulin dose and high-sensitivity C-reactive protein (hsCRP), nitrotyrosine, and pentraxin 3 in patients with insulin-treated type 2 diabetes.

PATIENTS AND METHODS

Eighty patients with type 2 diabetes treated with insulin for >6 months and with stable insulin doses (±10%) within 3 months before inclusion were enrolled in this study. Medical history, including use of insulin and insulin doses, concomitant diseases and medication, and anthropometric and routine biochemical parameters were collected for each patient. hsCRP, nitrotyrosine, and pentraxin 3 were measured in fasting conditions. Comparison analysis was performed according to the distribution in tertiles of insulin dose/kg of body weight, and linear regression adjusted for confounding factors was used to examine the associations between markers of inflammation, oxidative stress, and insulin dose.

RESULTS

In the comparison analysis, no statistically significant difference was found between hsCRP, nitrotyrosine, and pentraxin 3 levels across tertiles of insulin dose expressed as IU/kg of body weight (p for trend >0.05 for all comparisons) except a significantly higher hsCRP level in tertile 3 compared to tertile 1 (3.9±3.6 vs 6.1±3.8 mg/dL, p=0.035). In regression analysis, after adjustment for age, gender, smoking, body mass index, glycated hemoglobin, C-peptide, metformin, antiplatelet, and statin use, only hsCRP levels were statistically significant associated with insulin dose/kg of body weight (β=0.237, p=0.043).

CONCLUSION

In this sample of patients with type 2 diabetes treated with insulin for >6 months, hsCRP was positively associated with insulin doses. No such association was found for pentraxin 3, a more specific marker of vascular inflammation, and for nitrotyrosine as a marker of oxidative stress.

PPARγ deacetylation dissociates thiazolidinedione's metabolic benefits from its adverse effects

Thiazolidinediones (TZDs) are PPARγ agonists with potent insulin-sensitizing effects. However, their use has been curtailed by substantial adverse effects on weight, bone, heart, and hemodynamic balance. TZDs induce the deacetylation of PPARγ on K268 and K293 to cause the browning of white adipocytes. Here, we show that targeted PPARγ mutations resulting in constitutive deacetylation (K268R/K293R, 2KR) increased energy expenditure and protected from visceral adiposity and diet-induced obesity by augmenting brown remodeling of white adipose tissues. Strikingly, when 2KR mice were treated with rosiglitazone, they maintained the insulin-sensitizing, glucose-lowering response to TZDs, while displaying little, if any, adverse effects on fat deposition, bone density, fluid retention, and cardiac hypertrophy. Thus, deacetylation appears to fulfill the goal of dissociating the metabolic benefits of PPARγ activation from its adverse effects. Strategies to leverage PPARγ deacetylation may lead to the design of safer, more effective agonists of this nuclear receptor in the treatment of metabolic diseases.

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.

Recent progress of sodium-glucose transporter 2 inhibitors as potential antidiabetic agents

SGLT2 inhibitors were promising and novel antidiabetic drugs which suppressed glucose reabsorption and increased urinary glucose exertion. This review paper are aimed to summarize the recent progress of SGLT2 inhibitors during the last 5 years. This paper first summarizes the information of SGLT2 inhibitors, including mechanism, evolution and then focuses on the recent efforts on structure-activity relationships and structural optimization of SGLT2 inhibitors. Finally, the corresponding clinical therapeutic efficacy and adverse drug reaction in patients with Type 2 diabetes are discussed in detail.

Diabetes, Hypertension, and Cardiovascular Disease: Clinical Insights and Vascular Mechanisms

Hypertension and type 2 diabetes are common comorbidities. Hypertension is twice as frequent in patients with diabetes compared with those who do not have diabetes. Moreover, patients with hypertension often exhibit insulin resistance and are at greater risk of diabetes developing than are normotensive individuals. The major cause of morbidity and mortality in diabetes is cardiovascular disease, which is exacerbated by hypertension. Accordingly, diabetes and hypertension are closely interlinked because of similar risk factors, such as endothelial dysfunction, vascular inflammation, arterial remodelling, atherosclerosis, dyslipidemia, and obesity. There is also substantial overlap in the cardiovascular complications of diabetes and hypertension related primarily to microvascular and macrovascular disease. Common mechanisms, such as upregulation of the renin-angiotensin-aldosterone system, oxidative stress, inflammation, and activation of the immune system likely contribute to the close relationship between diabetes and hypertension. In this article we discuss diabetes and hypertension as comorbidities and discuss the pathophysiological features of vascular complications associated with these conditions. We also highlight some vascular mechanisms that predispose to both conditions, focusing on advanced glycation end products, oxidative stress, inflammation, the immune system, and microRNAs. Finally, we provide some insights into current therapies targeting diabetes and cardiovascular complications and introduce some new agents that may have vasoprotective therapeutic potential in diabetes.

Renal safety profile of sodium-glucose cotransporter-2 inhibitors and other safety data

The main effect of SGLT2 inhibitors is their glycosuric action. These drugs reverse the deleterious effect of increased glucose reabsorption by the renal tubule in persons with DM2. In terms of efficacy, SGLT2 inhibitors produce a mean HbA1c reduction of 0.8%, although higher initial HbA1c levels can show a larger decrease. In addition to these glycaemic effects, this drug class also favours weight loss and blood pressure control, without increasing hypoglycaemic episodes. Due to their insulin-independent mechanism of action, SGLT2 inhibitors can be used in monotherapy, in patients with metformin intolerance, or in combination with other glucose-lowering drugs, including insulin. These drugs have few secondary effects and most are related to their mechanism of action. The most frequent adverse effects are genitourinary infections, usually mycotic infections. SGLT2 inhibitors have an adequate cardiovascular safety profile. The development of ketoacidosis remains to be elucidated, and may be related to use in patients with insulinopenia. A randomised clinical trial of an SGLT2 inhibitor in patients with DM2 and underlying cardiovascular disease showed that its use in association with standard therapy slowed the progression of renal damage and reduced significant renal events such as doubling of serum creatinine values and initiation of dialysis. These effects are probably due to the favourable effects of SGLT2 inhibition on glomerular haemodynamics, by reducing hyperfiltration, to the reduction of glucose-induced tubular toxicity, as well as its beneficial effects on glycaemia, blood pressure, weight, and uricaemia.

Functional interplay between liver X receptor and AMP-activated protein kinase α inhibits atherosclerosis in apolipoprotein E-deficient mice - a new anti-atherogenic strategy

BACKGROUND AND PURPOSE

The liver X receptor (LXR) agonist T317 reduces atherosclerosis but induces fatty liver. Metformin activates energy metabolism by activating AMPKα. In this study, we determined if interactions between metformin and T317 could inhibit atherosclerosis without activation of hepatic lipogenesis.

EXPERIMENTAL APPROACH

Apolipoprotein E-deficient mice were treated with T317, metformin or both agents, in a high-fat diet for 16 weeks. Then, samples of aorta, liver, macrophage and serum were collected to determine atherosclerotic lesions, fatty liver, lipid profiles and expression of related proteins. Techniques used included immunohistochemistry, histology, qRT-PCR and Western blot.

KEY RESULTS

T317 inhibited en face and aortic root sinus lesions, and the inhibition was further enhanced by addition of metformin. Co-treatment with metformin and T317 increased lesion stability, by increasing collagen content, and reducing necrotic cores and calcification. Formation of macrophages/foam cells and their accumulation in arterial wall were inhibited by the co-treatment, which was accompanied by increased ABCA1/ABCG1 expression, reduced monocyte adhesion and apparent local proliferation of macrophages. Metformin blocked T317-induced fatty liver by inhibiting T317-induced hepatic LXRα nuclear translocation and expression of lipogenic genes and by activating AMPKα. Moreover, co-treatment with T317 and metformin improved triglyceride metabolism by inducing expression of adipose triglyceride lipase, hormone-sensitive lipase, PPARα and carnitine acetyltransferase and by inhibiting acyl-CoA:diacylglycerol acyltransferase 1 expression.

CONCLUSIONS AND IMPLICATIONS

Co-treatment with T317 and metformin inhibited the development of atherosclerosis without activation of lipogenesis, suggesting that combined treatment with T317 and metformin may be a novel approach to inhibition of atherosclerosis.