Effects of Sodium-glucose Cotransporter 2 Inhibitors on Amputation, Bone Fracture, and Cardiovascular Outcomes in Patients with Type 2 Diabetes Mellitus Using an Alternative Measure to the Hazard Ratio

Dipeptidyl peptidase-4 inhibitors, glucagon-like peptide 1 receptor agonists and sodium-glucose co-transporter-2 inhibitors for people with cardiovascular disease: a network meta-analysis

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of death globally. Recently, dipeptidyl peptidase-4 inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose co-transporter-2 inhibitors (SGLT2i) were approved for treating people with type 2 diabetes mellitus. Although metformin remains the first-line pharmacotherapy for people with type 2 diabetes mellitus, a body of evidence has recently emerged indicating that DPP4i, GLP-1RA and SGLT2i may exert positive effects on patients with known CVD.

OBJECTIVES

To systematically review the available evidence on the benefits and harms of DPP4i, GLP-1RA, and SGLT2i in people with established CVD, using network meta-analysis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and the Conference Proceedings Citation Index on 16 July 2020. We also searched clinical trials registers on 22 August 2020. We did not restrict by language or publication status.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) investigating DPP4i, GLP-1RA, or SGLT2i that included participants with established CVD. Outcome measures of interest were CVD mortality, fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, all-cause mortality, hospitalisation for heart failure (HF), and safety outcomes.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the results of searches to identify eligible studies and extracted study data. We used the GRADE approach to assess the certainty of the evidence. We conducted standard pairwise meta-analyses and network meta-analyses by pooling studies that we assessed to be of substantial homogeneity; subgroup and sensitivity analyses were also pursued to explore how study characteristics and potential effect modifiers could affect the robustness of our review findings. We analysed study data using the odds ratios (ORs) and log odds ratios (LORs) with their respective 95% confidence intervals (CIs) and credible intervals (Crls), where appropriate. We also performed narrative synthesis for included studies that were of substantial heterogeneity and that did not report quantitative data in a usable format, in order to discuss their individual findings and relevance to our review scope.

MAIN RESULTS

We included 31 studies (287 records), of which we pooled data from 20 studies (129,465 participants) for our meta-analysis. The majority of the included studies were at low risk of bias, using Cochrane's tool for assessing risk of bias. Among the 20 pooled studies, six investigated DPP4i, seven studied GLP-1RA, and the remaining seven trials evaluated SGLT2i. All outcome data described below were reported at the longest follow-up duration. 1. DPP4i versus placebo Our review suggests that DPP4i do not reduce any risk of efficacy outcomes: CVD mortality (OR 1.00, 95% CI 0.91 to 1.09; high-certainty evidence), myocardial infarction (OR 0.97, 95% CI 0.88 to 1.08; high-certainty evidence), stroke (OR 1.00, 95% CI 0.87 to 1.14; high-certainty evidence), and all-cause mortality (OR 1.03, 95% CI 0.96 to 1.11; high-certainty evidence). DPP4i probably do not reduce hospitalisation for HF (OR 0.99, 95% CI 0.80 to 1.23; moderate-certainty evidence). DPP4i may not increase the likelihood of worsening renal function (OR 1.08, 95% CI 0.88 to 1.33; low-certainty evidence) and probably do not increase the risk of bone fracture (OR 1.00, 95% CI 0.83 to 1.19; moderate-certainty evidence) or hypoglycaemia (OR 1.11, 95% CI 0.95 to 1.29; moderate-certainty evidence). They are likely to increase the risk of pancreatitis (OR 1.63, 95% CI 1.12 to 2.37; moderate-certainty evidence). 2. GLP-1RA versus placebo Our findings indicate that GLP-1RA reduce the risk of CV mortality (OR 0.87, 95% CI 0.79 to 0.95; high-certainty evidence), all-cause mortality (OR 0.88, 95% CI 0.82 to 0.95; high-certainty evidence), and stroke (OR 0.87, 95% CI 0.77 to 0.98; high-certainty evidence). GLP-1RA probably do not reduce the risk of myocardial infarction (OR 0.89, 95% CI 0.78 to 1.01; moderate-certainty evidence), and hospitalisation for HF (OR 0.95, 95% CI 0.85 to 1.06; high-certainty evidence). GLP-1RA may reduce the risk of worsening renal function (OR 0.61, 95% CI 0.44 to 0.84; low-certainty evidence), but may have no impact on pancreatitis (OR 0.96, 95% CI 0.68 to 1.35; low-certainty evidence). We are uncertain about the effect of GLP-1RA on hypoglycaemia and bone fractures. 3. SGLT2i versus placebo This review shows that SGLT2i probably reduce the risk of CV mortality (OR 0.82, 95% CI 0.70 to 0.95; moderate-certainty evidence), all-cause mortality (OR 0.84, 95% CI 0.74 to 0.96; moderate-certainty evidence), and reduce the risk of HF hospitalisation (OR 0.65, 95% CI 0.59 to 0.71; high-certainty evidence); they do not reduce the risk of myocardial infarction (OR 0.97, 95% CI 0.84 to 1.12; high-certainty evidence) and probably do not reduce the risk of stroke (OR 1.12, 95% CI 0.92 to 1.36; moderate-certainty evidence). In terms of treatment safety, SGLT2i probably reduce the incidence of worsening renal function (OR 0.59, 95% CI 0.43 to 0.82; moderate-certainty evidence), and probably have no effect on hypoglycaemia (OR 0.90, 95% CI 0.75 to 1.07; moderate-certainty evidence) or bone fracture (OR 1.02, 95% CI 0.88 to 1.18; high-certainty evidence), and may have no impact on pancreatitis (OR 0.85, 95% CI 0.39 to 1.86; low-certainty evidence). 4. Network meta-analysis Because we failed to identify direct comparisons between each class of the agents, findings from our network meta-analysis provided limited novel insights. Almost all findings from our network meta-analysis agree with those from the standard meta-analysis. GLP-1RA may not reduce the risk of stroke compared with placebo (OR 0.87, 95% CrI 0.75 to 1.0; moderate-certainty evidence), which showed similar odds estimates and wider 95% Crl compared with standard pairwise meta-analysis. Indirect estimates also supported comparison across all three classes. SGLT2i was ranked the best for CVD and all-cause mortality.

AUTHORS' CONCLUSIONS

Findings from both standard and network meta-analyses of moderate- to high-certainty evidence suggest that GLP-1RA and SGLT2i are likely to reduce the risk of CVD mortality and all-cause mortality in people with established CVD; high-certainty evidence demonstrates that treatment with SGLT2i reduce the risk of hospitalisation for HF, while moderate-certainty evidence likely supports the use of GLP-1RA to reduce fatal and non-fatal stroke. Future studies conducted in the non-diabetic CVD population will reveal the mechanisms behind how these agents improve clinical outcomes irrespective of their glucose-lowering effects.

Recent Advances in the Development of Type 2 Sodium-Glucose Cotransporter Inhibitors for the Treatment of Type 2 Diabetes Mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is one of the most serious and prevalent diseases worldwide. In the last decade, type 2 sodium-glucose cotransporter inhibitors (iSGLT2) were approved as alternative drugs for the pharmacological treatment of T2DM. The anti-hyperglycemic mechanism of action of these drugs involves glycosuria. In addition, SGLT2 inhibitors cause beneficial effects such as weight loss, a decrease in blood pressure, and others.

OBJECTIVE

This review aimed to describe the origin of SGLT2 inhibitors and analyze their recent development in preclinical and clinical trials.

RESULTS

In 2013, the FDA approved SGLT2 inhibitors as a new alternative for the treatment of T2DM. These drugs have shown good tolerance with few adverse effects in clinical trials. Additionally, new potential anti-T2DM agents based on iSGLT2 (O-, C-, and N-glucosides) have exhibited a favorable profile in preclinical evaluations, making them candidates for advanced clinical trials.

CONCLUSION

The clinical results of SGLT2 inhibitors show the importance of this drug class as new anti-T2DM agents with a potential dual effect. Additionally, the preclinical results of SGLT2 inhibitors favor the design and development of more selective new agents. However, several adverse effects could be a potential risk for patients.

Update on: effects of anti-diabetic drugs on bone metabolism

INTRODUCTION

Preclinical, clinical, and population-based studies have provided evidence that anti-diabetic drugs affect bone metabolism and may affect the risk of fracture in diabetic patients.

AREAS COVERED

An overview of the skeletal effects of anti-diabetic drugs used in type 2 diabetes is provided. Searches on AdisInsight, PubMed, and Medline databases were conducted up to 1^st July 2020. The latest evidence from randomized clinical trials and population-based studies on the skeletal safety of the most recent drugs (DPP-4i, GLP-1RA, and SGLT-2i) is provided.

EXPERT OPINION

Diabetic patients present with a higher risk of fracture for a given bone mineral density suggesting a role of bone quality in the etiology of diabetic fracture. Bone quality is difficult to assess in human clinical practice and the use of preclinical models provides valuable information on diabetic bone alterations. As several links have been established between bone and energy homeostasis, it is interesting to study the safety of anti-diabetic drugs on the skeleton. So far, evidence for the newest molecules suggests a neutral fracture risk, but further studies, especially in different types of patient populations (patients at risk or with history of cardiovascular disease, renal impairment, neuropathy) are required to fully appreciate this matter.

The effect of canagliflozin on amputation risk in the CANVAS program and the CREDENCE trial

AIM

To determine whether there was an explanation as to why the effects of the sodium-glucose co-transporter-2 (SGLT2) inhibitor canagliflozin on amputation risk vary between the CANVAS program and the CREDENCE trial.

METHODS

We performed a pooled analysis of patient-level data from the CANVAS program and the CREDENCE trial. Patient characteristics associated with amputation risk were assessed in univariable and multivariable regression models and compared between studies. Effects of canagliflozin on amputation risk were determined from Cox proportional hazards models and compared between studies, subgroups and for a range of amputation outcomes. Effects over time were explored by cumulative event curves.

RESULTS

In the CANVAS program (n = 10 142; median follow-up 2.4 years) and CREDENCE trial (n = 4401; median follow-up 2.5 years), 2.3% and 5.3% of participants, respectively, reported baseline amputation history. Key differences at baseline were the proportions with nephropathy (CREDENCE higher, 100% vs. 17.5%) and cardiovascular disease (CANVAS higher, 66% vs. 50%). There were 133 amputations in CREDENCE (3.0% annual event rate) and 187 amputations in CANVAS (1.8% annual event rate), with prior amputation being the strongest predictor of future amputation in both groups. Effects of canagliflozin on amputation risk were significantly different between trials (P_{heterogeneity} .02, I² = 82%), but this was not explained by participant or trial differences. There was no evidence that foot disease management protocols instituted during CREDENCE ameliorated amputation risk.

CONCLUSIONS

We identified no explanation for the difference in amputation risk between the CREDENCE trial and the CANVAS program. In the context of null effects of SGLT2 inhibition on amputation in CREDENCE and all other large trials, there is a possibility that the finding in CANVAS was the result of chance.

Safety and effectiveness of tofogliflozin in Japanese patients with type 2 diabetes mellitus: Results of 24-month interim analysis of a long-term post-marketing study (J-STEP/LT)

AIMS/INTRODUCTION

Tofogliflozin is a potent and highly selective sodium-glucose cotransporter 2 inhibitor, and is currently used to treat patients with type 2 diabetes mellitus. We designed a 3-year study of tofogliflozin in patients with type 2 diabetes mellitus to evaluate the safety and effectiveness in routine clinical practice. The 3- and 12-month interim analysis showed tofogliflozin was well-tolerated, safe and clinically effective. Here, we report the results of the 24-month interim analysis.

MATERIALS AND METHODS

This is a 3-year prospective, observational and multicenter post-marketing study (Japanese Study of Tofogliflozin with Type 2 Diabetes Mellitus Patients/Long Term).

RESULTS

Of the 6,897 patients enrolled, 6,712 and 6,461 patients were analyzed for the safety and effectiveness of tofogliflozin, respectively. During the 24-month observation period, the incidence rates of adverse drug reactions (ADRs) and serious adverse drug reactions were 11.25 and 1.21%, respectively. As to adverse drug reactions of special interest, the incidence rates of hypoglycemia, polyuria/pollakiuria, volume depletion-related events, urinary tract infections and genital infection were 0.83, 1.28, 1.46, 1.18 and 1.62%, respectively. Renal disorders, and cardiovascular and cerebrovascular disorders occurred in 0.63 and 0.76% of the patients, respectively. Glycated hemoglobin A1c and bodyweight decreased significantly by -0.70% (P < 0.0001) and -2.95 kg (P < 0.0001), respectively, from baseline to week 104 (last observation carried forward).

CONCLUSIONS

Significant safety concerns have not been observed, and clinical benefit including a long-term reduction in glycated hemoglobin A1c over a 104-week (24 months) observation period with weight loss was suggested in this 24-month interim analysis of the 3-year Japanese Study of Tofogliflozin with Type 2 Diabetes Mellitus Patients/Long Term in routine clinical practice.

Uses and Limitations of the Restricted Mean Survival Time: Illustrative Examples From Cardiovascular Outcomes and Mortality Trials in Type 2 Diabetes

The restricted mean survival time (RMST) has been advocated as an alternative or a supplement to the hazard ratio for reporting the effect of an intervention in a randomized clinical trial. The RMST difference allows quantification of the postponement of an outcome during a specified (restricted) interval and corresponds to the difference between the areas under the 2 survival curves for the intervention and control groups. This article presents examples of the use of the RMST in a research and a clinical context. First, the authors demonstrate how the RMST difference can answer research questions about the efficacy of different treatments. Estimates are presented for the effects of pharmacologic or strategy-driven glucose-lowering interventions for adults with type 2 diabetes from 36 trials and 9 follow-up studies reporting cardiovascular outcomes and mortality. The authors show how these measures may be used to mitigate uncertainty about the efficacy of intensive glucose control. Second, the authors demonstrate how the RMST difference may be used in the setting of a clinical consultation to guide the decision to start or discontinue a treatment. They then discuss the advantages of the RMST over the absolute risk difference, the number needed to treat, and the median survival time difference. They argue that the RMST difference is both easy to interpret and flexible in its application to different settings. Finally, they highlight the major limitations of the RMST, including difficulties in comparing studies of heterogeneous designs and in inferring the long-term effects of treatments using trials of short duration, and summarize the available statistical software for calculating the RMST.

Sodium-Glucose Co-Transporter 2 Inhibitors Compared with Sulfonylureas in Patients with Type 2 Diabetes Inadequately Controlled on Metformin: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

When metformin is insufficient for patients with type 2 diabetes mellitus (T2DM), the optimal adjunctive therapy is unclear. This meta-analysis was to compare the efficacy and safety of sodium-glucose co-transporter 2 (SGLT2) inhibitors with sulfonylureas (SUs) as second-line therapy in patients with T2DM inadequately controlled on metformin.

METHODS

We systematically searched PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for randomized controlled trials comparing SGLT2 inhibitors with SUs as add-on to metformin. Our primary endpoints were glycemic control, hypoglycemia, and change in weight. We assessed pooled data using a random-effects model.

RESULTS

Five trials involving 4300 participants were included in our meta-analysis. Compared with SUs, SGLT2 inhibitors led to no significant reduction in changes in HbA1c (mean difference [MD] - 0.06; 95% confidence interval [CI] [- 0.12, 0.08]), but less hypoglycemia as add-on to metformin (odds ratio [OR] 0.12; 95% CI [0.07, 0.21]). SGLT2 inhibitors led to a reduction in weight by about 3.5 kg; however, SUs caused a gain in weight by about 1 kg (MD - 4.39; 95% CI [- 4.64, - 4.14]). SGLT2 inhibitors also showed a reduction in blood pressure, but increased the incidence of genital tract infections compared with SUs. Interestingly, subgroup analysis by duration of interventions showed that reduction of HbA1c from baseline was similar between the two groups at 12-52 weeks, but SGLT2 inhibitors led to a greater reduction in HbA1c at 104-208 weeks.

CONCLUSIONS

Despite similar glycemic efficacy in a relatively short term, SGLT2 inhibitors are more effective in the longer term than SUs as add-on to metformin. In addition, SGLT2 inhibitors produce less hypoglycemic events and lead to greater reductions in weight and blood pressure compared with SUs.

An update on the safety of SGLT2 inhibitors

INTRODUCTION

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are recommended after metformin for a large spectrum of patients with type 2 diabetes, because of a favorable benefit/risk profile despite a variety of adverse events.

AREAS COVERED

This narrative review discusses the safety profile of SGLT2is: initial concerns (cardiovascular safety, acute renal failure, hypoglycemia, urinary and genital infections, volume depletion, bladder cancer), further concerns (euglycemic ketoacidosis, bone fractures) and more recent concerns (lower limb amputation, Fournier's gangrene).

EXPERT OPINION

Overall, the safety profile of SGLT2is is good. The only increased adverse event that was consistently reported in clinical trials and observational studies is genital mycotic infections, with only a borderline increase in urinary tract infections. Among clinical trials, only the CANVAS program reported an unexpected increase in bone fractures and peripheral amputations. A variety of rare adverse events have been described as case reports, including ketoacidosis, amputations and Fournier gangrene, which led to specific warnings by regulatory agencies. Identifying predisposing patient's characteristics and/or precipitating clinical conditions would help prevent the most severe complications. These adverse events should not mask the overall cardiovascular and renal benefit of SGLT2is, especially in patients with type 2 diabetes at high cardiovascular risk.

Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors: A Clinician's Guide

This comprehensive review covers the historical background, physiology, application in type 2 diabetes, novel uses, cardiovascular benefits, side effects and contraindications of sodium-glucose cotransporter-2 (SGLT2) inhibitors. SGLT2 inhibitors are an insulin-independent class of oral antihyperglycemic medication that clinicians use in the treatment of type 2 diabetes. Multiple landmark clinical trials support the effectiveness of SGLT2 inhibitors in reducing blood glucose levels, but it is important to understand when to properly utilize them. SGLT2 inhibitors are the most beneficial as an adjunct medication in addition to metformin in patients with a history of cardiovascular or renal disease who need further hemoglobin A1c reduction. The novel mechanism of action also demands clinicians be aware of the side effects not typically experienced with other oral antihyperglycemic drugs, such as genital tract infections, lower leg amputations, electrolyte disturbances and bone fractures. On top of their benefits in type 2 diabetes, novel uses for SGLT2 inhibitors are being uncovered. Diabetic patients with non-alcoholic fatty liver disease, who are at an increased risk of cirrhosis and hepatocellular carcinoma, experience a clinically significant reduction in serum alanine aminotransferase levels. SGLT2 inhibitors are also effective at lowering body weight in obese individuals and decreasing systolic blood pressure. Dual SGLT1/SGLT2 inhibitors are currently being investigated as possibly the first oral medication for type 1 diabetes.