Cardiovascular safety and efficacy of metformin-SGLT2i versus metformin-sulfonylureas in type 2 diabetes: systematic review and meta-analysis of randomized controlled trials

The Effectiveness of Metformin in Diabetes Prevention: A Systematic Review and Meta-Analysis

Diabetes mellitus is a growing global health concern, and prevention strategies play a crucial role in reducing its burden. Metformin has been widely studied as a potential intervention for diabetes prevention, but its overall effectiveness and impact on various populations remain unclear. This study aims to provide a comprehensive synthesis of the available evidence on the effectiveness of metformin in diabetes prevention. A systematic search was conducted in PubMed, Scopus, ScienceDirect, and Google Scholar for articles published from inception to June 2023. The reference lists of the included studies were also searched to retrieve possible additional studies. Any quantitative data were analyzed using Review Manager 5.4. A P-value of 0.05 was adopted as the significance threshold. Our analysis included 17 studies with a total sample size of 30,474. Our meta-analysis included two key analyses. First, the meta-analysis evaluating the effects of metformin on prediabetes demonstrated a significant reduction in the risk of progressing to type 2 diabetes mellitus (T2DM). The pooled odds ratio (OR) was 0.65 (95% confidence interval [CI] 0.53-0.80), indicating a 35% lower odds of developing T2DM among individuals with prediabetes who received metformin interventions compared to control groups. Secondly, the meta-analysis assessing the efficacy of metformin interventions in preventing T2DM yielded a significant reduction in the risk of developing the disease. The pooled risk ratio was 0.58 (95% CI 0.44-0.77), indicating a 42% lower risk of developing T2DM in individuals receiving metformin interventions compared to those in non-metformin intervention groups. These findings provide strong evidence for the effectiveness of metformin in preventing the progression of prediabetes to T2DM and reducing the overall incidence of the disease. The review demonstrated that metformin is effective in reducing the risk of developing diabetes mellitus among individuals at risk for the disease. The findings highlight the potential of metformin as a valuable intervention for diabetes prevention, particularly in high-risk populations.

Association of Sodium-Glucose Cotransporter 2 Inhibitors with Osteomyelitis and Other Lower Limb Safety Outcomes in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Our aim was to evaluate osteomyelitis and other major lower limb safety outcomes (i.e., peripheral artery disease or PAD, ulcers, atraumatic fractures, amputations, symmetric polyneuropathy, and infections) in patients affected by type 2 diabetes mellitus (T2DM) and treated with sodium-glucose cotransporter 2 inhibitors (SGLT2-is). We thus performed a systematic review and meta-analysis of randomised controlled trials (RCTs) comparing SGLT2-is at approved doses for T2DM with a placebo or standard of care. MEDLINE, Embase, and Cochrane CENTRAL were searched through August 2022. Separate intention-to-treat analyses were implemented for each molecule to calculate Mantel-Haenszel risk ratios (RR_MH) with 95% confidence intervals (CIs) through a random-effects model. We processed data from 42 RCTs for a total of 29,491 and 23,052 patients, respectively assigned to SGLT2-i and comparator groups. SGLT2-is showed a pooled neutral effect on osteomyelitis, PAD, fractures, and symmetric polyneuropathy, whereas slightly deleterious sway on ulcers (RR_MH 1.39 [1.01-1.91]), amputations (RR_MH 1.27 [1.04-1.55]), and infections (RR_MH 1.20 [1.02-1.40]). In conclusion, SGLT2-is appear to not significantly interfere with the onset of osteomyelitis, PAD, lower limb fractures, or symmetric polyneuropathy, even though the number of these events proved consistently higher in the investigational groups; otherwise, local ulcers, amputations, and overall infections may be favoured by their employment. This study is registered with the Open Science Framework (OSF).

The Effect of Sodium-Glucose Co-Transporter 2 Inhibitors on Stroke and Atrial Fibrillation: A Systematic Review and Meta-Analysis

The effect of Sodium-glucose cotransporter-2 (SGLT2) inhibitors on the occurrence of AF and stroke remains unclear due to underpowered individual studies. We aim to conduct a meta-analysis including all studies that have evaluated the effects of SGLT2 inhibitors on the occurrence of AF and stroke. We queried electronic databases (PubMed, Cochrane CENTRAL and ClinicalTrials.gov) for randomized controlled trials assessing the effect of SGLT2 inhibitors. Trials were selected if they reported 1 or both of the pre-specified outcomes of stroke and AF. Results were pooled using a random-effects model. Subgroup analysis was conducted to study patients with T2DM, HF, CVD and CKD. 56 trials comprising 111,773 patients were included. SGLT2 inhibitors significantly reduced the incidence of AF across all studies (RR:0.87; 95%CI, [0.76-0.99], P=0.03, I^2=0%) especially when used as monotherapy (RR:0.87; 95%CI, [0.77-0.99], P=0.04, I^2=0%) and among T2DM patients (RR:0.83; 95%CI, [0.72-0.97], P=0.02, I^2=0%). The risk of stroke was not reduced after treatment with SGLT2 inhibitors (RR:0.97; 95%CI, [0.89-1.07], P=0.56, I^2=0%) and this was consistent when given as monotherapy (RR:0.98; 95%CI, [0.89-1.07], P=0.62, I^2=0%) or combination therapy (RR:0.58; 95%CI, [0.17-1.95], P=0.38, I^2=0%). This result was consistent among the 3 subpopulations: T2DM, CVD and HF, however benefit was seen in patients with CKD (eGFR<90) (RR:0.85; 95%CI, [0.75-0.97], P=0.02, I^2=0%). SGLT2 inhibitors significantly reduce the incidence of atrial fibrillation, and this effect is primarily seen when given as monotherapy and in patients with T2DM. However, they have no significant effect on the incidence of stroke, except for in patients with Stage 2 CKD and beyond (eGFR<90).

Systematic review and meta-analysis of head-to-head trials comparing sulfonylureas and low hypoglycaemic risk antidiabetic drugs

BACKGROUND

Safety of sulfonylurea drugs in the treatment of Type 2 Diabetes is still under debate. The aim of this study was to compare the all-cause mortality and cardiovascular adverse events of sulfonylureas and drugs with a low risk for hypoglycaemia in adults with type 2 diabetes.

METHODS

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

MEDLINE (PubMed, OVID), Embase, Cochrane Central Register of Controlled Trials, CINAHL, WOS and Lilacs.

STUDY SELECTION

Randomised controlled head-to-head trials that compared sulfonylureas with active control with low hypoglycaemic potential in adults (≥ 18 years old) with type 2 diabetes published up to August 2015. The drug classes involved in the analysis were metformin, dipeptidyl peptidase-4 (DPP-4) inhibitors, sodium-glucose co-transporter-2 (SGLT-2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists.

OUTCOMES

The primary endpoint was all-cause mortality. The secondary endpoints were MACE, cardiovascular events and severe hypoglycaemia.

SYNTHESIS OF RESULTS

Two reviewers checked study eligibility, independently extracted data and assessed quality with disagreements resolved through discussion. We assessed the risk of bias of the included studies using the Cochrane risk of bias tool for randomized trials v2. Pooled odds ratios (ORs) were estimated by using fixed effects model. The study is registered on PROSPERO (26/05/2016 CRD42016038780).

RESULTS

Our final analysis comprised 31 studies (26,204 patients, 11,711 patients given sulfonylureas and 14,493 given comparator drugs). In comparison to drugs with low hypoglycaemic potential, sulfonylureas had higher odds for all-cause mortality (OR 1.32, 95% CI 1.00-1.75), MACE (OR 1.32, 95% CI 1.07-1.61), myocardial infarction (fatal and non-fatal) (OR 1.67, 95% CI 1.17-2.38) and hypoglycaemia (OR 5.24, 95% CI 4.20-6.55). Subsequent sensitivity analysis revealed differences in the effect of sulfonylureas, with an increased risk of all-cause mortality with glipizide but not the other molecules.

CONCLUSION

Our meta-analysis raises concern about the safety of SUs compared to alternative drugs involved in current analysis. Important differences may exist within the drug class, and glimepiride seems to have best safety profile.

Metformin treatment is associated with improved outcome in patients with diabetes and advanced heart failure (HFrEF)

The role of metformin (MET) in the treatment of patients with advanced HFrEF and type 2 diabetes mellitus (DM) is not firmly established. We studied the impact of MET on metabolic profile, quality of life (QoL) and survival in these patients. A total of 847 stable patients with advanced HFrEF (57.4 ± 11.3 years, 67.7% NYHA III/IV, LVEF 23.6 ± 5.8%) underwent clinical and laboratory evaluation and were prospectively followed for a median of 1126 (IQRs 410; 1781) days for occurrence of death, urgent heart transplantation or mechanical circulatory support implantation. A subgroup of 380 patients (44.9%) had DM, 87 of DM patients (22.9%) were treated with MET. Despite worse insulin sensitivity and more severe DM (higher BMI, HbA1c, worse insulin resistance), MET-treated patients exhibited more stable HF marked by lower BNP level (400 vs. 642 ng/l), better LV and RV function, lower mitral and tricuspid regurgitation severity, were using smaller doses of diuretics (all p < 0.05). Further, they had higher eGFR (69.23 vs. 63.34 ml/min/1.73 m2) and better QoL (MLHFQ: 36 vs. 48 points, p = 0.002). Compared to diabetics treated with other glucose-lowering agents, MET-treated patients had better event-free survival even after adjustment for BNP, BMI and eGFR (p = 0.035). Propensity score-matched analysis with 17 covariates yielded 81 pairs of patients and showed a significantly better survival for MET-treated subgroup (p = 0.01). MET treatment in patients with advanced HFrEF and DM is associated with improved outcome by mechanisms beyond the improvement of blood glucose control.

HIV Protease Inhibitors and Insulin Sensitivity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Protease inhibitors (PIs) are believed to affect insulin sensitivity. We aimed to analyze the effect of PIs on insulin sensitivity and the onset of diabetes mellitus (DM) in patients with HIV. Methodology: We searched PubMed, Google Scholar, ClinicalTrals.gov, and the WHO International Clinical Trials Registry Platform till November 2020 for randomized controlled trials (RCTs) that studied the effects of PIs on insulin sensitivity and DM in patients with HIV. We followed the PRISMA and PICOS frameworks to develop the search strategy. We used the random-effects meta-analysis model to estimate the mean difference (MD), standardized mean difference (SMD), and risk ratios for our outcomes, using Stata 14 software. Results: We included nine RCTs that enrolled 1,000 participants, with their ages ranging from 18 to 69 years. The parameters and investigations used in the studies to determine insulin sensitivity were glucose disposal rates, hyperglycemia, and mean glucose uptake. The majority of results showed an association between PIs and insulin sensitivity. The pooled analysis showed no statistically significant difference in insulin sensitivity with atazanavir, whether the study was performed on healthy individuals for a short term or long term in combination with other drugs like tenofovir or emtricitabine [SMD = 0.375, 95% CI (0.035, 0.714)]. The analysis showed reduced glucose disposal rates and hence reduced insulin sensitivity with lopinavir (heterogeneity chi-squared = 0.68, I-squared [variation in SMD attributable to heterogeneity] = 0.0%, p = 0.031). The heterogeneity with chi-squared was substantial (61-80%), while with I-squared was not significant (0-40%), p = 0.031). Less adverse events were observed with atazanavir than with lopinavir [RR = 0.987, 95% CI (0.849, 1.124)]. Darunavir and indinavir did not demonstrate any significant changes in insulin sensitivity. Most of the studies were found to have a low risk of bias. Conclusions: There are significant variations in the effects of PIs on insulin sensitivity and onsets of DM. Atazanavir, fosamprenavir, and darunavir did not demonstrate any significant changes in insulin sensitivity, compared to the rest of the group. There is a need to assess the benefits of PIs against the long-term risk of impaired insulin sensitivity. All patients newly diagnosed with HIV should have DM investigations before the start of ARVs and routinely. RCTs should focus on sub-Saharan Africa as the region is worst affected by HIV, but limited studies have been documented.

Ertugliflozin + metformin as a treatment option for type 2 diabetes

Introduction: Sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduce blood glucose and glycosylated hemoglobin (HbA1c), the risk of hospitalization for heart failure (HF) and the incidence of serious adverse kidney function events (chronic kidney disease, CKD) in patients with type 2 diabetes mellitus (T2DM). Ertugliflozin is the last SGLT2i approved by Food and Drug Administration (FDA) in the USA and European Medical Agency (EMA) in Europe for the treatment of T2DM alone or in combination with other drugs.Areas covered: The authors critically discuss in this drug evaluation the safety and efficacy of the ertugliflozin + metformin combination in patients with T2DM without complications, those with CKD, or those with heart failure (HF). Furthermore, the authors discuss the results of the VERTIS CV trial (MK-8835-004), the trials NCT01986881 and NCT01986855 and other smaller studies.Expert opinion: The ertugliflozin + metformin combination is safe and effective in patients with T2DM with renal impairment, HF of any kind, or those without diabetic complications. These have practical implications that will help diabetologists, cardiologists, internists, nephrologists and general practitioners in selecting the proper combination of SGLT2i on top of metformin, if needed.

Dysfunctional High-Density Lipoproteins in Type 2 Diabetes Mellitus: Molecular Mechanisms and Therapeutic Implications

High density lipoproteins (HDLs) are commonly known for their anti-atherogenic properties that include functions such as the promotion of cholesterol efflux and reverse cholesterol transport, as well as antioxidant and anti-inflammatory activities. However, because of some chronic inflammatory diseases, such as type 2 diabetes mellitus (T2DM), significant changes occur in HDLs in terms of both structure and composition. These alterations lead to the loss of HDLs' physiological functions, to transformation into dysfunctional lipoproteins, and to increased risk of cardiovascular disease (CVD). In this review, we describe the main HDL structural/functional alterations observed in T2DM and the molecular mechanisms involved in these T2DM-derived modifications. Finally, the main available therapeutic interventions targeting HDL in diabetes are discussed.

A Critical Review of the Evidence That Metformin Is a Putative Anti-Aging Drug That Enhances Healthspan and Extends Lifespan

The numerous beneficial health outcomes associated with the use of metformin to treat patients with type 2 diabetes (T2DM), together with data from pre-clinical studies in animals including the nematode, C. elegans, and mice have prompted investigations into whether metformin has therapeutic utility as an anti-aging drug that may also extend lifespan. Indeed, clinical trials, including the MILES (Metformin In Longevity Study) and TAME (Targeting Aging with Metformin), have been designed to assess the potential benefits of metformin as an anti-aging drug. Preliminary analysis of results from MILES indicate that metformin may induce anti-aging transcriptional changes; however it remains controversial as to whether metformin is protective in those subjects free of disease. Furthermore, despite clinical use for over 60 years as an anti-diabetic drug, the cellular mechanisms by which metformin exerts either its actions remain unclear. In this review, we have critically evaluated the literature that has investigated the effects of metformin on aging, healthspan and lifespan in humans as well as other species. In preparing this review, particular attention has been placed on the strength and reproducibility of data and quality of the study protocols with respect to the pharmacokinetic and pharmacodynamic properties of metformin. We conclude that despite data in support of anti-aging benefits, the evidence that metformin increases lifespan remains controversial. However, via its ability to reduce early mortality associated with various diseases, including diabetes, cardiovascular disease, cognitive decline and cancer, metformin can improve healthspan thereby extending the period of life spent in good health. Based on the available evidence we conclude that the beneficial effects of metformin on aging and healthspan are primarily indirect via its effects on cellular metabolism and result from its anti-hyperglycemic action, enhancing insulin sensitivity, reduction of oxidative stress and protective effects on the endothelium and vascular function.