A registry-based randomised trial comparing an SGLT2 inhibitor and metformin as standard treatment of early stage type 2 diabetes (SMARTEST): Rationale, design and protocol

Advances in the Insulin-Heart Axis: Current Therapies and Future Directions

The insulin-heart axis plays a pivotal role in the pathophysiology of cardiovascular disease (CVD) in insulin-resistant states, including type 2 diabetes mellitus. Insulin resistance disrupts glucose and lipid metabolism, leading to systemic inflammation, oxidative stress, and atherogenesis, which contribute to heart failure (HF) and other CVDs. This review was conducted by systematically searching PubMed, Scopus, and Web of Science databases for peer-reviewed studies published in the past decade, focusing on therapeutic interventions targeting the insulin-heart axis. Studies were selected based on their relevance to insulin resistance, cardiovascular outcomes, and the efficacy of pharmacologic treatments. Key findings from the review highlight the efficacy of lifestyle modifications, such as dietary changes and physical activity, which remain the cornerstone of managing insulin resistance and improving cardiovascular outcomes. Moreover, pharmacologic interventions, such as metformin, sodium-glucose cotransporter 2 inhibitors, glucagon-like peptide-1 receptor agonists, and dipeptidyl peptidase-4 inhibitors, have shown efficacy in reducing cardiovascular risk by addressing metabolic dysfunction, reducing inflammation, and improving endothelial function. Furthermore, emerging treatments, such as angiotensin receptor-neprilysin inhibitors, and mechanical interventions like ventricular assist devices offer new avenues for managing HF in insulin-resistant patients. The potential of these therapies to improve left ventricular ejection fraction and reverse pathological cardiac remodeling highlights the importance of early intervention. However, challenges remain in optimizing treatment regimens and understanding the long-term cardiovascular effects of these agents. Future research should focus on personalized approaches that integrate lifestyle and pharmacologic therapies to effectively target the insulin-heart axis and mitigate the burden of cardiovascular complications in insulin-resistant populations.

Metformin: evidence from preclinical and clinical studies for potential novel applications in cardiovascular disease

INTRODUCTION

For a long time, metformin has been the first-line treatment for glycaemic control in type 2 diabetes, however, the results of recent cardiovascular outcome trials of sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide 1 receptor agonists have caused many to question metformin's position in the guidelines. Although there are several plausible mechanisms by which metformin might have beneficial cardiovascular effects, for example its anti-inflammatory effects and metabolic properties, and numerous observational data suggesting improved cardiovascular outcomes with metformin use, the main randomised clinical trial data for metformin was published over 20 years ago. Nevertheless, the overwhelming majority of participants in contemporary type 2 diabetes trials were prescribed metformin.

AREAS COVERED

In this review we will summarise the potential mechanisms of cardiovascular benefit with metformin, before discussing clinical data in individuals with or without diabetes.

EXPERT OPINION

Metformin may have some cardiovascular benefit in patients with and without diabetes, however the majority of clinical trials were small and are before the use SGLT2 inhibitors and GLP1-RAs. Larger contemporary randomised trials with metformin evaluating its cardiovascular benefit are warranted.

Registry-based randomised clinical trials: a remedy for evidence-based diabetes care?

This narrative review describes a new approach to navigation in a challenging landscape of clinical drug development in diabetes. Successful outcome studies in recent years have led to new indications and guidelines in type 2 diabetes, yet the number of clinical trials in diabetes is now declining. This is due to many environmental factors acting in concert, including the prioritisation of funding for other diseases, high costs of large randomised clinical trials, increase in regulatory requirements and limited entry of novel candidate drugs. There is a need for novel and cost-effective paradigms of clinical development to meet these and other challenges. The concept of registry-based randomised clinical trials (RRCTs) is an attractive option. In this review we focus on type 2 diabetes and the prevention of cardiovascular and microvascular comorbidities and mortality, using the Swedish SMARTEST trial as an example of an RRCT. We also give some examples from other disease areas. The RRCT concept is a novel, cost-effective and scientifically sound approach for conducting large-scale diabetes trials in a real-world setting.

Effect of metformin on adverse outcomes in T2DM patients: Systemic review and meta-analysis of observational studies

Background

The cardiovascular protection effect of metformin on patients with type 2 diabetes mellitus (T2DM) remains inconclusive. This systemic review and meta-analysis were to estimate the effect of metformin on mortality and cardiovascular events among patients with T2DM.

Methods

A search of the Pubmed and EMBASE databases up to December 2021 was performed. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled by a random-effects model with an inverse variance method.

Results

A total of 39 studies involving 2473009 T2DM patients were adopted. Compared to non-metformin therapy, the use of metformin was not significantly associated with a reduced risk of major adverse cardiovascular event (MACE) (HR = 1.06, 95%CI 0.91–1.22; I² = 82%), hospitalization (HR = 0.85, 95%CI 0.64–1.13; I² = 98%), heart failure (HR = 0.86, 95%CI 0.60–1.25; I² = 99%), stroke (HR = 1.16, 95%CI 0.88–1.53; I² = 84%), and risk of AMI (HR = 0.88, 95%CI 0.69–1.14; I² = 88%) in T2DM patients. Metformin was also not associated with significantly lowered risk of MACE compared to dipeptidyl peptidase-4 inhibitor (DPP-4i) in T2DM patients (HR = 0.95, 95%CI 0.73–1.23; I² = 84%).

Conclusions

The effect of metformin on some cardiovascular outcomes was not significantly better than the non-metformin therapy or DPP-4i in T2DM patients based on observational studies.

Cardiovascular Outcomes in Patients Initiating First-Line Treatment of Type 2 Diabetes With Sodium-Glucose Cotransporter-2 Inhibitors Versus Metformin : A Cohort Study

BACKGROUND

Evidence on the risk for cardiovascular events associated with use of first-line sodium-glucose cotransporter-2 inhibitors (SGLT-2i) compared with metformin is limited.

OBJECTIVE

To assess cardiovascular outcomes among adults with type 2 diabetes (T2D) who initiated first-line treatment with SGLT-2i versus metformin.

DESIGN

Population-based cohort study.

SETTING

Claims data from 2 large U.S. commercial and Medicare databases (April 2013 to March 2020).

PARTICIPANTS

Patients with T2D aged 18 years and older (>65 years in Medicare) initiating treatment with SGLT-2i or metformin during April 2013 to March 2020, without any use of antidiabetic medications before cohort entry, were identified. After 1:2 propensity score matching in each database, pooled hazard ratios (HRs) and 95% CIs were reported.

INTERVENTION

First-line SGLT-2i (canagliflozin, empagliflozin, or dapagliflozin) or metformin.

MEASUREMENTS

Primary outcomes were a composite of hospitalization for myocardial infarction (MI), hospitalization for ischemic or hemorrhagic stroke or all-cause mortality (MI/stroke/mortality), and a composite of hospitalization for heart failure (HHF) or all-cause mortality (HHF/mortality). Safety outcomes including genital infections were assessed.

RESULTS

Among 8613 first-line SGLT-2i initiators matched to 17 226 metformin initiators, SGLT-2i initiators had a similar risk for MI/stroke/mortality (HR, 0.96; 95% CI, 0.77 to 1.19) and a lower risk for HHF/mortality (HR, 0.80; CI, 0.66 to 0.97) during a mean follow-up of 12 months. Initiators receiving SGLT-2i showed a lower risk for HHF (HR, 0.78; CI, 0.63 to 0.97), a numerically lower risk for MI (HR, 0.70; CI, 0.48 to 1.00), and similar risk for stroke, mortality, and MI/stroke/HHF/mortality compared with metformin. Initiators receiving SGLT-2i had a higher risk for genital infections (HR, 2.19; CI, 1.91 to 2.51) and otherwise similar safety as those receiving metformin.

LIMITATION

Treatment selection was not randomized.

CONCLUSION

As first-line T2D treatment, initiators receiving SGLT-2i showed a similar risk for MI/stroke/mortality, lower risk for HHF/mortality and HHF, and a similar safety profile except for an increased risk for genital infections compared with those receiving metformin.

PRIMARY FUNDING SOURCE

Brigham and Women's Hospital and Harvard Medical School.

Knowledge and practice of community pharmacists towards SGLT2 inhibitors

Background: Sodium/glucose cotransporter 2 (SGLT2) inhibitors are a new class of oral anti-diabetic drugs which improve glycaemic control in type 2 diabetes mellitus (T2DM) by preventing the kidney from reabsorbing glucose back to blood. Community pharmacists have long-term relationships with most of their chronic patients, so they play a key role in care for people with diabetes. Therefore, the objective of this study was to assess pharmacists' knowledge and practice towards SGLT2 inhibitors. Methods: A cross-sectional study was conducted to meet the study objectives. A convenience sample of 348 community pharmacists in Jordan was recruited. knowledge and practice were assessed using a self-administered questionnaire created for the purpose of this study. Results: A total of 400 community pharmacists were reached, of whom 348 answered the survey (response rate 87%). The results indicated that SGLT2 inhibitors knowledge score among community pharmacists in Jordan was 6.61 (out of 12). Factors like age, gender, location of the pharmacy, years of pharmacists' experience had no effect on knowledge score; however, pharmacists who attended training courses on diabetes had higher knowledge scores. Additionally, pharmacists' dispensing practice toward SGLT2 inhibitors had insufficient knowledge, such as lack of knowledge about the superiority of SGLT2 inhibitors over other anti-diabetics and inability to give the best advice to patients. Conclusions: Our findings reflect a moderate knowledge among community pharmacists about SGLT2 inhibitors which may negatively affect the patients' outcome; thus, continuous education for the pharmacists is essential.

Knowledge and practice of community pharmacists towards SGLT2 inhibitors

Background: Sodium/glucose cotransporter 2 (SGLT2) inhibitors are a new class of oral anti-diabetic drugs which improve glycaemic control in type 2 diabetes mellitus (T2DM) by preventing the kidney from reabsorbing glucose back to blood. Community pharmacists have long-term relationships with most of their chronic patients, so they play a key role in care for people with diabetes. Therefore, the objective of this study was to assess pharmacists' knowledge and practice towards SGLT2 inhibitors. Thus, improving pharmacists' knowledge about this group of medications could improve the treatment outcome of people with diabetes. Methods: A cross-sectional study was conducted to meet the study objectives. A convenience sample of 348 community pharmacists in Jordan was recruited. knowledge and practice were assessed using a self-administered questionnaire created for the purpose of this study. Results: A total of 400 community pharmacists were reached, of whom 348 answered the survey (response rate 87%). The results indicated that SGLT2 inhibitors knowledge score among community pharmacists in Jordan was 6.61 (out of 12). Factors like age, gender, location of the pharmacy, years of pharmacists' experience had no effect on knowledge score; however, pharmacists who attended training courses on diabetes had higher knowledge scores. Additionally, pharmacists' dispensing practice toward SGLT2 inhibitors had insufficient knowledge, such as lack of knowledge about the superiority of SGLT2 inhibitors over other anti-diabetics and inability to give the best advice to patients. Conclusions: Our findings reflect a moderate knowledge among community pharmacists about SGLT2 inhibitors which may negatively affect the patients' outcome; thus, continuous education for the pharmacists is essential.