Sodium-glucose co-transporter-2 inhibitor use and risk of lower-extremity amputation: Evolving questions, evolving answers

The Potential Impact of SGLT2-I in Diabetic Foot Prevention: Promising Pathophysiologic Implications, State of the Art, and Future Perspectives-A Narrative Review

The impact of diabetic foot (DF) on the healthcare system represents a major public health problem, leading to a considerable clinical and economic burden. The factors contributing to DF's development and progression are strongly interconnected, including metabolic causes, neuropathy, arteriopathy, and inflammatory changes. Sodium-glucose cotransporter 2 inhibitors (SGLT2-i), novel oral hypoglycemic drugs used as an adjunct to standard treatment, have recently changed the pharmacological management of diabetes. Nevertheless, data about the risk of limb amputation, discordant and limited to canagliflozin, which is currently avoided in the case of peripheral artery disease, have potentially discouraged the design of specific studies targeting DF. There is good evidence for the single immunomodulatory, neuroprotective, and beneficial vascular effects of SGLT2-i. Still, there is no clinical evidence about the early use of SGLT2-i in diabetic foot due to the lack of longitudinal and prospective studies proving the effect of these drugs without confounders. This narrative review aims to discuss the main evidence about the impact of SGLT2-i on the three complications of diabetes implicated in the development of DF, the state of the art, and the potential future implications.

Key results from observational studies and real-world evidence of sodium-glucose cotransporter-2 inhibitor effectiveness and safety in reducing cardio-renal risk

Sodium-glucose cotransporter 2 (SGLT2) inhibitors, originally designed to manage blood sugar levels in individuals with type 2 diabetes (T2D), have emerged as a crucial class of drugs for managing cardio-renal diseases. These drugs work by targeting the SGLT2 protein in the kidneys, promoting the excretion of glucose and influencing metabolic pathways beyond glucose control. The relationship between cardio-renal diseases and SGLT2 inhibitors has been explored through landmark trials and real-world evidence (RWE) studies, demonstrating significant reductions in cardio-renal complications. This review discusses the importance of RWE studies alongside randomized controlled trials in understanding the real-world effectiveness and safety of SGLT2 inhibitors. It outlines the advantages and disadvantages of RWE compared to RCTs, highlighting their complementary roles in providing comprehensive insights into treatment outcomes. By examining a range of RWE studies, the review underscores the cardio-renal benefits of SGLT2 inhibitors across various patient populations. Safety assessments indicate that SGLT2 inhibitors are generally well tolerated, with severe adverse events being rare. Common issues, such as genital mycotic infections and urinary tract infections, are acknowledged, alongside less frequent but significant adverse events including diabetic ketoacidosis, lower-limb amputations, and bone fractures. In summary, SGLT2 inhibitors show promising cardio-renal protective effects in real-world scenarios across diverse populations in T2D, indicating their potential as early intervention measures. Continued research is essential for gaining a thorough understanding of their long-term effects and safety profiles.

Safety of sodium-glucose co-transporter-2 inhibitors on amputation across categories of baseline cardiovascular disease and diuretics use in patients with type 2 diabetes

AIM

To assess the risk of amputation associated with sodium-glucose co-transporter-2 inhibitors (SGLT2is) among patients with type 2 diabetes, across categories of baseline cardiovascular disease (CVD) and diuretic use (DU).

MATERIALS AND METHODS

We conducted an active comparator, new-user cohort study using Korea's nationwide claims data (2015-2020). The study cohort consisted of patients with type 2 diabetes who initiated SGLT2is or dipeptidyl peptidase-4 inhibitors (DPP4is). Cohort entry was defined by first prescription date. We then classified patients into four discrete subcohorts based on their baseline status of CVD and DU as (1) CVD+/DU+, (2) CVD+/DU-, (3) CVD-/DU+ and (4) CVD-/DU-. We performed 1:1 propensity score (PS) matching within each cohort and estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for the risk of amputation with SGLT2is versus DPP4is using Cox models.

RESULTS

We identified 219 900 PS-matched pairs of SGLT2is and DPP4is (CVD+/DU+, n = 11 719; CVD+/DU-, n = 26 092; CVD-/DU+, n = 26 894; and CVD-/DU-, n = 155 195), with well-balanced baseline covariates across all cohorts. Significantly lower risks of amputation with SGLT2is versus DPP4is were found in CVD+/DU+ (HR 0.36, 95% CI 0.14-0.90), CVD+/DU- (0.45, 0.21-0.99) and CVD-/DU- (0.48, 0.33-0.70), but not in CVD-/DU+ (0.54, 0.26-1.12). Consistent trends in estimates were found across various sensitivity analyses.

CONCLUSIONS

Initiating SGLT2is against DPP4is did not increase the risk of amputation across patient populations of varying vulnerability. These findings based on routine practice will reassure clinicians of the safety of SGLT2is with regard to amputation risk in selected high-risk patients with type 2 diabetes.

Safety of sodium-glucose transporter 2 (SGLT-2) inhibitors in patients with type 2 diabetes: a meta-analysis of cohort studies

Aims: This study aimed to investigate the association between the use of sodium-glucose transporter 2 inhibitors (SGLT-2i) and the risk of diabetic ketoacidosis (DKA), lower limb amputation (LLA), urinary tract infections (UTI), genital tract infections (GTI), bone fracture, and hypoglycemia in cohort studies. Methods: A systematic search was conducted in the PubMed and Embase databases to identify cohort studies comparing the safety of SGLT-2i versus other glucose-lowering drugs (oGLD) in patients with type 2 diabetes mellitus (T2DM). The quality of the studies was assessed using the Newcastle-Ottawa Scale. Primary endpoints were DKA and LLA, while secondary endpoints included UTI, GTI, bone fracture, and hypoglycemia. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated. Results: A total of 9,911,454 patients from 40 cohort studies were included in the analysis. SGLT-2i use was associated with a higher risk of DKA (HR: 1.21, 95% CI: 1.07-1.38, p = 0.003) and GTI (HR: 2.72, 95% CI: 2.48-2.98, p < 0.01). However, it was not associated with an increased risk of LLA (HR: 1.06, 95% CI: 0.92-1.23, p = 0.42), UTI (HR: 0.99, 95% CI: 0.89-1.10, p = 0.83), or bone fracture (HR: 0.99, 95% CI: 0.94-1.04, p = 0.66). Furthermore, SGLT-2i was associated with a reduced risk of hypoglycemia. Furthermore, compared to dipeptidyl peptidase 4 inhibitors, SGLT-2i as a class and individually was associated with an increased risk of DKA. Canagliflozin specifically increased the risk of LLA (HR: 1.19, 95% CI: 1.04-1.36, p = 0.01). The subgroup analysis suggested that SGLT-2i increased the risk of LLA among patients with a history of cardiovascular disease. Conclusion: SGLT-2i versus oGLD was associated with a similar occurrence of LLA, UTI, and bone fracture. However, SGLT-2i was associated with a higher risk of DKA and GTI than oGLD. These findings provide valuable information on the safety profile of SGLT-2i in patients with T2DM and can help inform clinical decision-making.

Effects of SGLT2 inhibitors and GLP1-receptor agonists on cardiovascular and limb events in peripheral artery disease: A review

Peripheral artery disease (PAD) and diabetes mellitus are two overwhelming health problems associated with major cardiovascular (CV) and limb events, in addition to increased mortality, despite advances in medical therapies including statins and renin-angiotensin system inhibitors. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1-receptor agonists (GLP1-RA) are two new antihyperglycemic drug classes that have been associated with a significant reduction of major adverse cardiovascular events (MACE) in patients with type 2 diabetes (T2D) and CV risk. Whereas most studies had enrolled patients with T2D and concurrent CV disease (CVD), patients with PAD were obviously underrepresented. Furthermore, there was a signal of increased risk of amputation in one of the main trials with canagliflozin. We aim to provide a general review of the current literature and summarize societal guideline recommendations addressing the role of SGLT2i and GLP1-RA drugs in patients with CVD focusing on the PAD population when data are available. Endpoints of interest were MACE and, when available, major adverse limb events (MALE).

Safety and Effectiveness of Empagliflozin in Korean Patients with Type 2 Diabetes Mellitus: Results from a Nationwide Post-Marketing Surveillance

BACKGROUND

To evaluate the safety and effectiveness of empagliflozin in routine clinical settings, we collected and assessed the clinical profiles of Korean patients with type 2 diabetes mellitus.

METHODS

This was a post-marketing surveillance study of empagliflozin 10 and 25 mg. Information on adverse events and adverse drug reactions (ADRs) was collected as safety data sets. Available effectiveness outcomes, including glycosylated hemoglobin (HbA1c) level, fasting plasma glucose, body weight, and blood pressure, were assessed.

RESULTS

The incidence rate of ADRs was 5.14% in the safety dataset (n=3,231). Pollakiuria, pruritis genital, and weight loss were the most common ADRs. ADRs of special interest accounted for only 1.18%, and there were no serious events that led to mortality or hospitalization. In the effectiveness data set (n=2,567), empagliflozin significantly reduced the mean HbA1c level and body weight during the study period by -0.68%±1.39% and -1.91±3.37 kg (both P<0.0001), respectively. In addition, shorter disease duration, absence of dyslipidemia, and higher baseline HbA1c levels were identified as the clinical features characteristic of a "responder" to empagliflozin therapy.

CONCLUSION

Empagliflozin is a safe and potent glucose-lowering drug in routine use among Korean patients with type 2 diabetes mellitus. It is expected to have better glycemic efficacy in Korean patients with poorly controlled type 2 diabetes mellitus.

Risk of lower extremity amputations in patients with type 2 diabetes using sodium-glucose co-transporter 2 inhibitors

AIMS

To compare the influence of sodium-glucose co-transporter 2 inhibitors (SGLT2i) and dipeptidyl peptidase-4 inhibitors (DPP-4i) on the risk of lower extremity amputations in patients with type 2 diabetes in Slovenia.

METHODS

This retrospective cohort study included patients aged 40 years or more who were administered a newly introduced SGLT2i or DPP-4i between June 2014 and June 2018. Patients treated with insulin at baseline and patients with a history of amputation were excluded. Patients were matched in a 1:1 ratio using propensity score matching. Survival analysis was performed; hazard ratio (HR) and ratios of cumulative hazards at 1, 2, 3, and 4 years were estimated. On-treatment and intention-to-treat approaches were used.

RESULTS

The study cohort (mean age: 64 years) consisted of 2,939 new users of SGLT2i (empagliflozin, 59%; dapagliflozin, 41%) matched to 2,939 new users of DPP-4i. In the on-treatment analysis (median follow-up of 2 years), the incidence of amputations was higher in SGLT2i than in DPP-4i users (4.2 vs. 2.7 per 1,000 patient years), resulting in a HR of 1.58 (95% CI 0.85-2.92; p = 0.145). An intention-to-treat analysis yielded to similar HR of 1.86 (95% CI: 1.10-3.14; p = 0.020). There was no difference in amputation rates in the first two years, but SGLT2i users had a 2.81-fold higher (95% CI: 1.63-4.84; p = 0.007) cumulative hazard of amputation at 4 years than did DPP-4i users.

CONCLUSIONS

Compared with DPP-4i use, SGLT2i use did not result in a statistically significant higher overall risk of lower extremity amputations. However, the results suggest that SGLT2i may increase the risk of amputation with long-term use.

Effect of SGLT2 inhibitors versus DPP4 inhibitors or GLP-1 agonists on diabetic foot-related extremity amputation in patients with T2DM: A meta-analysis

AIM

To compare the contribution of sodium-glucose cotransporter-2 inhibitors (SGLT2is) with that of DPP4i or GLP-1ra toward lower extremity amputation rate.

METHODS

Electronic databases were searched for articles published on the differences between the rates of lower extremity amputation among patients with type 2 diabetes mellitus (T2DM) undergoing SGLT2i treatment and those undergoing other anti-hyperglycemic agent (dipeptidyl peptidase-4 inhibitors [DPP4is], glucagon-like peptide-1 receptor agonist [GLP-1as], or sulfonylurea [SUs]) treatments. Random-effect models were used to generate data if heterogeneity was detected.

RESULTS

Eight studies based on retrospective case-control designs with propensity matching were included. The propensity score-matching method increased credibility. Compared with SGLT2i treatment, DPP4i or GLP-1a treatment tended to result in a higher amputation rate (pooled hazard ratio [HR] = 1.1, 95% confidence interval [CI]: 0.98-1.23), whereas SU treatment resulted in similar amputation rates (pooled HR = 0.92, 95% CI: 0.74-1.13). After excluding the heterogeneous study, the meta-analysis of the remaining studies attained a statistical value (pooled HR = 0.81, 95% CI: 0.65-1.01).

CONCLUSION

The study findings suggest that, with respect to diabetic foot-related limb amputations, SGLT2is are not superior to novel anti-hyperglycemic agents (DPP4is and GLP-1as) or other types of oral hypoglycemic agents (SUs). Therefore, SGLT2is may not have significantly positive effects on the prognosis for T2DM patients with complicated diabetic foot.

Initiation of SGLT2 Inhibitors and the Risk of Lower Extremity Minor and Major Amputation in Patients with Type 2 Diabetes and Peripheral Arterial Disease: A Health Claims Data Analysis

OBJECTIVE

To assess the association between long term risk of hospitalisation for heart failure (HHF) and lower extremity minor and major amputation (LEA) in patients initiating sodium glucose cotransporter 2 inhibitors (SGLT2i) suffering from type 2 diabetes and peripheral arterial disease (PAD). Outcomes were compared with patients without PAD and evaluated separately for the time periods before and after the official warning of the European Medicines Agency (EMA) in early 2017.

METHODS

This study used BARMER German health claims data including all patients suffering from type 2 diabetes initiating SGLT2i therapy between 1 January 2013 and 31 December 2019 with follow up until the end of 2020. New users of glucagon like peptide 1 receptor agonists (GLP1-RAs) were used as active comparators. Inverse probability weighting with truncated stabilised weights was used to adjust for confounding, and five year risks of HHF and LEA were estimated using Cox regression. Periods before and after the EMA warning were analysed separately and stratified by presence of concomitant PAD.

RESULTS

In total, 44 284 (13.6% PAD) and 56 878 (16.3% PAD) patients initiated SGLT2i or GLP1-RA, respectively. Before the EMA warning, initiation of SGLT2i was associated with a lower risk of HHF in patients with PAD (hazard ratio, HR, 0.85, 95% confidence interval, CI, 0.73 - 0.99) and a higher risk of LEA in patients without PAD (HR 1.79, 95% CI 1.04 - 2.92). After the EMA warning, the efficacy and safety endpoints were no longer statistically different between groups.

CONCLUSION

The results from this large nationwide real world study highlight that PAD patients exhibit generally high amputation risks. This study refutes the idea that the presence of PAD explains the excess LEA risk associated with initiation of SGLT2i. The fact that differentials among study groups diminished after the EMA warning in early 2017 emphasises that regulatory surveillance measures worked in everyday clinical practice.

Efficacy / safety balance of DPP-4 inhibitors versus SGLT2 inhibitors in elderly patients with type 2 diabetes

Dipeptidyl peptidase-4 inhibitors (DPP-4is) and sodium-glucose cotransporter type 2 inhibitors (SGLT2is) offer new options for the oral management of type 2 diabetes mellitus (T2DM), with the advantage in the elderly population to be devoid of a high risk of hypoglycaemia. SGLT2is have also shown benefits regarding cardiovascular (heart failure) and renal protection, including in patients with T2DM aged ≥ 65 years while DPP-4is have only proved cardiovascular and renal safety without superiority compared with placebo. The glucose-lowering efficacy of the two pharmacological classes is almost similar including in older patients with T2DM. However, the tolerance and safety profile may be highly different and overall more favourable with DPP-4is than with SGLT2is. Some adverse events have been reported with SGLT2is which may be more prevalent or severe in older patients than in younger patients. The present comprehensive review focuses on the benefit/risk balance in the elderly population with T2DM by comparing the profile of DPP-4is and SGLT2is regarding the following potential issues: metabolic disorders (hypoglycaemia and diabetic ketoacidosis); cardiac and vascular issues (atheromatous cardiovascular disease, heart failure, volume reduction hypotension, and lower limb amputations); renal endpoints including acute renal injury; risk of infections; digestive disorders; bone and skin adverse events; and cancer risk. Both DPP-4is and SGLT2is have their own advantages and disadvantages. Personalised treatment is recommended based upon the efficacy/safety profile of each drug class and individual patient characteristics that may be markedly different among the heterogeneous population of older individuals with T2DM.

Careful use to minimize adverse events of oral antidiabetic medications in the elderly

INTRODUCTION

An increasing number of older patients has type 2 diabetes treated with different oral antidiabetic agents whose safety may raise concern considering some particularities of a heterogeneous elderly population.

AREAS COVERED

This article discusses some characteristics of older patients that could increase the risk of adverse events, with a focus on hypoglycemia. It describes the most frequent and/or severe complications reported in the elderly in both randomized controlled trials and observational studies with metformin, sulfonylureas, meglitinides, alpha-glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase-4 inhibitors (gliptins) and sodium-glucose cotransporter type 2 inhibitors (gliflozins).

EXPERT OPINION

Old patients may present comorbidities (renal impairment, vascular disease, heart failure, risk of dehydration, osteoporosis, cognitive dysfunction) that could increase the risk of severe adverse events. Sulfonylureas (and meglitinides) induce hypoglycemia, which may be associated with falls/fractures and cardiovascular events. Medications lacking hypoglycemia should be preferred. Gliptins appear to have the best tolerance/safety profile whereas gliflozins exert a cardiorenal protection. However, data are lacking in very old or frailty old patients so that caution and appropriate supervision of such patients are required. Taking advantage of a large choice of pharmacotherapies, personalized treatment is recommended based upon both drug safety profiles and old patient individual characteristics.

Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2i) Exposure and Outcomes in Type 2 Diabetes: A Systematic Review of Population-Based Observational Studies

INTRODUCTION

Sodium-glucose co-transporter 2 inhibitors (SGLT2is) are licensed for the treatment of type 2 diabetes (T2D) and more recently for heart failure with or without diabetes. They have been shown to be safe (from the cardiovascular (CV) perspective) and effective (in terms of glycaemia, and in some cases, in reducing CV events) in extensive randomised controlled trials (RCTs). However, there remain concerns regarding the generalisability of these findings (to those ineligible for RCT participation) and about non-CV safety. For effectiveness, population-based pharmacoepidemiology studies can confirm and extend the findings of RCTs to broader populations and explore safety, for which RCTs are not usually powered, in more detail.

METHODS

A pre-planned and registered ((International PROSPEctive Register Of Systematic Reviews) PROSPERO registration CRD42019160792) systematic review of population-based studies investigating SGLT2i effectiveness and safety, following Meta-analyses Of Observational Studies in Epidemiology (MOOSE) guidelines was conducted.

RESULTS

A total of 37 studies were identified (total n = 1,300,184 adults; total follow-up 910,577 person-years; exposures: SGLT2i class, canagliflozin, dapagliflozin and empagliflozin) exploring CV disease (CVD) outcomes, acute kidney injury (AKI), lower limb amputation (LLA), diabetic ketoacidosis (DKA), bone fracture, urinary tract infection (UTI), genital mycotic infection (GMI), hypoglycaemia, pancreatitis and venous thromboembolism. For CV and mortality outcomes, studies confirmed the associated safety of these drugs and correlated closely with the findings from RCTs, which may extend to primary CVD prevention (major adverse cardiovascular events point estimate range (PER) hazard ratio (HR) 0.78-0.94; hospitalised heart failure PER HR 0.48-0.79). For safety outcomes, SGLT2i exposure was not associated with an increased risk of AKI (PER HR 0.40-0.96), fractures (PER HR 0.87-1.11), hypoglycaemia (PER HR 0.76-2.49) or UTI (PER HR 0.72-0.98). There was a signal for increased association for GMIs (PER HR 2.08-3.15), and possibly for LLA (PER HR 0.74-2.79) and DKA (PER HR 0.96-2.14), but with considerable uncertainty.

CONCLUSION

In T2D, SGLT2is appear safe from the CV perspective and may have associated benefit in primary as well as secondary CVD prevention. For safety, they may be associated with an increased risk of GMI, LLA and DKA, although longer follow-up studies are needed.

Use of Sodium-Glucose Co-Transporter-2-Inhibitors (SGLT2-Is) and Risk of Lower Limb Amputation

BACKGROUND

Treatment with sodium-glucose co-transporter-2-inhibitors (SGLT2-Is), such as canagliflozin, has been associated with an increased risk of lower limb amputations (LLAs) in type 2 diabetes mellitus (T2DM). However, conflicting results have been reported for different SGLT2-Is and the underlying mechanism is unclear.

OBJECTIVE

To investigate the risk of LLA and diabetic foot ulcer with SGLT2-I use compared to other anti-diabetic drugs and to explore hypovolemia as a potential underlying mechanism.

METHODS

A cohort study was conducted using data from the Clinical Practice Research Datalink GOLD (2013-2019). The study population (N=51,847) consisted of T2DM patients over 18 years of age with at least one prescription of a non-insulin anti-diabetic drug. Concomitant diuretic use and the presence of signs of hypovolemia were determined to assess the potential underlying mechanism. Cox proportional hazard models were used to estimate the hazard ratio (HR) for LLA in current SGLT2-I use versus current sulphonylurea (SU) use. Analyses were adjusted for lifestyle variables, comorbidities, and concomitant drug use.

RESULTS

Current SGLT2-I use was not associated with an increased risk of LLA compared to current SU use (fully adjusted HR 0.70; 95% confidence interval 0.38-1.29). Concomitant use of diuretics and the presence of signs of hypovolemia were not associated with an increased risk of LLA.

CONCLUSION

Use of SGLT2-Is, with or without signs of hypovolemia, was not associated with an increased risk of LLA or DFU versus current SU use. Future studies powered to detect potential differences between individual SGLT2-Is are required to rule out a canagliflozin-specific effect.

Using machine learning to identify diabetes patients with canagliflozin prescriptions at high-risk of lower extremity amputation using real-world data

AIMS

Canagliflozin, a sodium-glucose cotransporter 2 inhibitor indicated for lowering glucose, has been increasingly used in diabetes patients because of its beneficial effects on cardiovascular and renal outcomes. However, clinical trials have documented an increased risk of lower extremity amputations (LEA) associated with canagliflozin. We applied machine learning methods to predict LEA among diabetes patients treated with canagliflozin.

METHODS

Using claims data from a 5% random sample of Medicare beneficiaries, we identified 13 904 diabetes individuals initiating canagliflozin between April 2013 and December 2016. The samples were randomly and equally split into training and testing sets. We identified 41 predictor candidates using information from the year prior to canagliflozin initiation, and applied four machine learning approaches (elastic net, least absolute shrinkage and selection operator [LASSO], gradient boosting machine and random forests) to predict LEA risk after canagliflozin initiation.

RESULTS

The incidence rate of LEA was 0.57% over a median 1.5 years follow-up. LASSO produced the best prediction, yielding a C-statistic of 0.81 (95% CI: 0.76, 0.86). Among individuals categorized in the top 5% of the risk score, the actual incidence rate of LEA was 3.74%. Among the 16 factors selected by LASSO, history of LEA [adjusted odds ratio (aOR): 33.6 (13.8, 81.9)] and loop diuretic use [aOR: 3.6 (1.8,7.3)] had the strongest associations with LEA incidence.

CONCLUSIONS

Our machine learning model efficiently predicted the risk of LEA among diabetes patients undergoing canagliflozin treatment. The risk score may support optimized treatment decisions and thus improve health outcomes of diabetes patients.

Cardiovascular outcomes associated with SGLT-2 inhibitors versus other glucose-lowering drugs in patients with type 2 diabetes: A real-world systematic review and meta-analysis

BACKGROUND AND AIMS

Glucose lowering agents that reduce the risk of major adverse cardiovascular events (MACE) would be considered a major advance. The reduction of cardiovascular risk by sodium-glucose cotransporter 2 inhibitors (SGLT-2i) has been confirmed by some large-scale randomized controlled studies (RCTs) and systematic reviews of RCTs, but exact indicators of cardiovascular risk remained controversial. Whether consistent results can be obtained in clinical practice is unclear. Therefore, in this meta-analysis, we analyzed the real-world effect of SGLT-2i on cardiovascular outcome in patients with type 2 diabetes mellitus (T2DM).

METHODS

We did a real-world systematic review and meta-analysis of cardiovascular outcome of SGLT-2i in patients with T2DM. We searched PubMed and Embase for trials published up to October 23, 2019. Data search and extraction were completed with a standardized data form and any discrepancies were resolved by consensus. The primary outcome was MACE and all-cause mortality (ACM). Secondary outcomes were hospitalization for heart failure (HHF), atrial fibrillation (AF), myocardial infarction (MI), stroke, cardiovascular mortality (CVM), unstable angina (UA), heart failure (HF). Odds ratio (OR) with 95% CIs were pooled across trials, and cardiovascular outcomes were stratified by baseline incidence of cardiovascular disease (CVD), usage rate of cardiovascular benefit drug, follow-up period and region.

RESULTS

Fourteen trials enrolling 3,157,259 patients were included. SGLT-2i reduced MACE (OR, 0.71; 95% CI 0.67,0.75, P<0.001) and ACM (OR, 0.53; 95% CI 0.49,0.57, P<0.001) compared to other glucose lowering drugs (oGLD). Compared with oGLD, SGLT-2i had significantly lowered the risk of HHF (OR, 0.56; 95% CI 0.46,0.68, P<0.001), MI (OR, 0.77; 95% CI 0.73,0.81, P<0.001), stroke (OR, 0.75; 95% CI 0.72,0.78, P<0.001), CVM (OR, 0.58; 95% CI 0.49,0.69, P<0.001) and HF (OR, 0.56; 95% CI 0.48,0.67, P<0.001), but there was no benefit from UA or AF. SGLT-2i significantly reduced the risk of severe hypoglycemia (OR, 0.78; 95% CI 0.69,0.90, P<0.001) and lower limb amputation (OR, 0.83; 95% CI 0.71,0.98, P<0.001), but it may increase the risk of diabetic ketoacidosis. Subgroup analysis showed SGLT-2i reduced the risk of MACE, ACM, HHF, MI, stroke, CVM and HF with a similar benefit regardless of the incidence of CVD was (20-30)% or < 15%, (15-30)% or <15% have been treated with GLP-1 receptor agonists (GLP-1RA), >80% or <70% have been treated with statins or both GLP-1RA and statins. SGLT-2i reduced the risk of ACM in low-risk population (P<0.001). No inconsistencies were found when stratification was performed at 1 or (3-4) years of follow-up except for BKA followed up for 1 year. SGLT-2i showed similar cardiovascular benefits in the Nordic countries, Asia and the United States.

CONCLUSIONS

The predominant impact of SGLT-2i is on cardiovascular outcome driven predominantly by reduction in MACE, ACM, HHF, MI, stroke, CVM, HF, but not UA or AF. SGLT-2i has robust benefits on reducing MACE, ACM, HHF, MI, stroke, CVM and HF regardless of a history of usage rate of GLP-1RA and/or statins and /or metformin. SGLT-2i does not increase the risk of severe hypoglycemia and lower limb amputation.

Comparison of the risk of SGLT2is and NonSGLT2is in leading to amputation: A network meta-analysis

OBJECTIVE

Whether sodium-glucose cotransporter 2 inhibitors (SGLT2is) increase the risk of amputation or not remains controversial. We aimed to evaluate the relative risk of different SGLT2is and Non-SGLT2i antihyperglycemic drugs (NonSGLT2is) in leading to amputation by network meta-analysis of large sample studies.

METHODS

We searched Embase and PubMed for relevant large sample studies. We conducted Bayesian network meta-analysis using random-effects model. Effect size was presented as hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Seventeen large studies involving 1 million SGLT2i users and 3 million NonSGLT2i users were included in network meta-analysis. SGLT2is [HR (95% CI): 1.38 (1.02, 1.91)] versus NonSGLT2is significantly increased the amputation risk, whereas SGLT2is [HR (95% CI): 1.45 (0.94, 2.17)] versus placebo did not. Compared with glucagon-like peptide 1 receptor agonists (GLP1RAs), canagliflozin [HR (95% CI): 1.5 (1.01, 2.33)] along with incorporative SGLT2is [HR (95% CI): 1.64 (1.07, 2.53)] significantly increased the amputation risk, whereas empagliflozin [HR (95% CI): 1.46 (0.83, 2.67)] and dapagliflozin [HR (95% CI): 1.22 (0.7, 2.23)] did not due to the wide 95% CIs of HRs.

CONCLUSION

Although SGLT2is versus placebo do not significantly increase the amputation risk, SGLT2is (especially, canagliflozin) versus NonSGLT2is (especially, GLP1RAs) significantly increase that risk.

Sodium-Glucose Cotransporter 2 Inhibitors and the Risk of Below-Knee Amputation: A Multicenter Observational Study

OBJECTIVE

Reports of amputations associated with sodium-glucose cotransporter 2 (SGLT2) inhibitors have been inconsistent. We aimed to compare the risk of below-knee amputation with SGLT2 inhibitors versus dipeptidyl peptidase 4 (DPP-4) inhibitors among patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

This multicenter observational study used administrative health care databases from seven Canadian provinces and the U.K. Incident SGLT2 inhibitor users were matched to DPP-4 inhibitor users using a prevalent new-user design and time-conditional propensity scores. Cox proportional hazards models were used to estimate site-specific adjusted hazard ratios (HR) and corresponding 95% CIs of incident below-knee amputation for SGLT2 inhibitor versus DPP-4 inhibitor users. Random effects meta-analyses were used to pool the site-specific results.

RESULTS

The study cohort included 207,817 incident SGLT2 inhibitor users matched to 207,817 DPP-4 inhibitor users. During a mean exposed follow-up time of 11 months, the amputation rate was 1.3 per 1,000 person-years among SGLT2 inhibitor users and 1.5 per 1,000 person-years among DPP-4 inhibitor users. The adjusted HR of below-knee amputations associated with SGLT2 inhibitor use compared with DPP-4 inhibitor use was 0.88 (95% CI 0.71-1.09). Similar results were obtained in stratified analyses by specific SGLT2 inhibitor molecule.

CONCLUSIONS

In this large multicenter observational study, there was no association between SGLT2 inhibitor use and incident below-knee amputations among patients with type 2 diabetes compared with DPP-4 inhibitor use. While these findings provide some reassurance, studies with a longer duration of follow-up are needed to assess potential long-term effects.

Real-world evidence: the devil is in the detail

Much has been written about real-world evidence (RWE), a concept that offers an understanding of the effects of healthcare interventions using routine clinical data. The reflection of diverse real-world practices is a double-edged sword that makes RWE attractive but also opens doors to several biases that need to be minimised both in the design and analytical phases of non-experimental studies. Additionally, it is critical to ensure that researchers who conduct these studies possess adequate methodological expertise and ability to accurately implement these methods. Critical design elements to be considered should include a clearly defined research question using a causal inference framework, choice of a fit-for-purpose data source, inclusion of new users of a treatment with comparators that are as similar as possible to that group, accurately classifying person-time and deciding censoring approaches. Having taken measures to minimise bias 'by design', the next step is to implement appropriate analytical techniques (for example propensity scores) to minimise the remnant potential biases. A clear protocol should be provided at the beginning of the study and a report of the results after, including caveats to consider. We also point the readers to readings on some novel analytical methods as well as newer areas of application of RWE. While there is no one-size-fits-all solution to evaluating RWE studies, we have focused our discussion on key methods and issues commonly encountered in comparative observational cohort studies with the hope that readers are better equipped to evaluate non-experimental studies that they encounter in the future. Graphical abstract.

Derivation and validation of a clinical prediction model for assessing the risk of lower extremity amputation in patients with type 2 diabetes

AIM

This study aims to develop and validate a lower extremity amputation (LEA) risk score system in persons with type 2 diabetes.

METHODS

A retrospective population-based cohort study was conducted among eligible 21,484 participants in the derivation set and 10,742 participants in the validation set who were enrolled in the Taiwan National Diabetes Care Management Program. The risk score system was developed following the steps proposed by the Framingham Heart Study with a Cox proportional hazards model algorithm. Discrimination ability was assessed by the receiver operating characteristic curve, and calibration was performed by Hosmer-Lemeshow test.

RESULTS

A total of 504 patients developed LEA at an average follow-up of 7.4 years. The point scores were derived from 15 predictors as follows: age, gender, duration of type 2 diabetes, body mass index, HbA1c, triglyceride, eGFR, variation of fasting blood glucose, comorbidities of stroke, diabetes retinopathy, hypoglycemia and foot ulcer, anti-diabetes medication, and use of diuretics and nitrates. The c-statistics for predicting 3-, 5-, and 8-year LEA risks were 0.80 [95% confidence interval (CI) 0.76-0.83], 0.78 (0.75-0.81), and 0.76 (0.74-0.79) in the derivation set, respectively, and 0.81 (0.76-0.85), 0.77 (0.73-0.81), and 0.74 (0.71-0.77) in the validation set, respectively.

CONCLUSIONS

A new risk score for LEA was developed and validated in the clinical setting with good discriminatory ability. Poor glycemic control, glucose variation, comorbidities, and medication use were identified as predictive factors for LEA in patients with type 2 diabetes.

Association between sodium-glucose cotransporter 2 (SGLT2) inhibitors and lower extremity amputation: A systematic review and meta-analysis

Background

The association between sodium-glucose cotransporter 2 inhibitors (SGLT2i’s) and lower extremity amputation is unclear.

Purpose

To systematically review randomized control trials (RCTs) and observational studies quantifying risk of lower extremity amputations associated with SGLT2i use.

Data sources and study selection

We searched PubMed, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials from January 2011 to February 2020 for RCTs and observational studies including lower extremity amputation outcomes for individuals with type 2 diabetes mellitus treated with SGLT2i’s vs. alternative treatments or placebo.

Data extraction and synthesis

Two reviewers independently extracted data.

Main outcomes and measures

Our primary outcome was risk of lower limb amputation. Secondary outcomes included peripheral arterial disease, peripheral vascular disease, venous ulcerations, and diabetic foot infections. We also evaluated the risk of bias. We conducted random and fixed effects relative risk meta-analysis of RCTs.

Results

After screening 2,006 studies, 12 RCTs and 18 observational studies were included, of which 7 RCTs and 18 observational studies had at least one event. The random effects meta-analysis of 7 RCTs suggested the absence of a statistically significant association between SGLT2i exposure with evidence of substantial statistical heterogeneity (n = 424/23,716 vs n = 267/18,737 in controls; RR 1.28, CI’s 0.93–1.76; I² = 62.0%; p = 0.12) whereas fixed effects analysis showed an increased risk with statistical heterogeneity (RR 1.27, 1.09–1.48; I² = 62%; p = 0.003). Subgroup analysis of canagliflozin vs placebo showed a statistically significantly increased risk in a fixed effects meta-analysis (n = 2 RCTs, RR 1.59, 1.26–2.01; I² = 88%; p = 0.0001) whereas the meta-analysis of dapagliflozin or empagliflozin (n = 2 RCTs each) and a single RCT for ertugliflozin did not show a significantly increased risk. The findings from observational studies were too heterogeneous to be pooled in a meta-analysis and draw meaningful conclusions. Both randomized and observational studies were of generally good methodological quality.

Conclusions

Overall, there was no consistent evidence of SGLT2i exposure and increased risk of amputation. The increased risk of amputation seen in the large, long-term Canagliflozin Cardiovascular Assessment Study (CANVAS) trial for canagliflozin, and select observational studies, merits continued exploration.

Novel glucose lowering agents are associated with a lower risk of cardiovascular and adverse events in type 2 diabetes: A population based analysis

BACKGROUND

Recent randomized control trials have described a protective cardiovascular effect of novel glucose lowering drugs in patients at high cardiovascular risk. Whether these second-line agents have similar effects in the general population is unknown. We aimed to compare the risk of major cardiovascular and adverse events in new users of sodium-glucose cotransporter-2 inhibitors (SGLT-2i), dipeptidyl peptidase-4 inhibitor (DPP-4i), glucagon-like peptide 1 agonist (GLP-1a), and sulfonylurea in T2DM patients not controlled on metformin therapy.

METHODS

Retrospective cohort study using the MarketScan database (2011-2015). We selected T2DM individuals who were newly dispensed sulfonylureas, SGLT-2i, DPP-4i, or GLP-1a, as second-line therapy, added to metformin. Cohort entry was defined by date of first prescription of the second-line agent. Time to first non-fatal cardiovascular or adverse event was compared using Cox regression models adjusted for confounders.

RESULTS

Among 118,341 T2DM patients using metformin (mean age: 56), most were at low cardiovascular risk (4% with previous cardiovascular or cerebrovascular event). During a median follow-up of 10 months compared with sulfonylureas users, cardiovascular risk was lower in users of SGLT-2i (aHR = 0.61; 95% CI: 0.40-0.97), DPP-4i (aHR = 0.79; 95% CI: 0.69-0.90) and GLP-1a (aHR = 0.65; 95% CI: 0.48-0.89). Serious adverse events were rare but compared with sulfonylurea, the risk was lower in new users of novel glucose lowering agents.

CONCLUSION

In our analyses, which included patients with and without prior cardiovascular disease, initiating novel glucose lowering drugs as second-line therapy for T2DM was associated with a lower risk of cardiovascular and adverse events than sulfonylurea initiation.

Canagliflozin and Amputation Risk: Evidence So Far

The CANVAS program detected a 2-fold increased risk of lower limb amputation in patients treated with canagliflozin compared with those with placebo. This adverse effect was not confirmed in the CREDENCE trial. Moreover, randomized controlled trials with other agents in this class, dapagliflozin and empagliflozin, did not detect increased risk of amputation. Observational studies, cohort studies, and pharmacovigilance reports with sodium-glucose cotransporter 2 inhibitor (SGLT2i) have reported conflicting results. Whether this adverse event is a drug effect specific to canagliflozin, or a SGLT2i class effect, remains controversial. Until more evidence emerges, clinicians should avoid using SGLT2i, especially canagliflozin, in patients with previous amputations or existing foot ulceration.

Use of sodium glucose cotransporter 2 inhibitors and risk of major cardiovascular events and heart failure: Scandinavian register based cohort study

OBJECTIVE

To investigate the cardiovascular effectiveness of sodium glucose cotransporter 2 (SGLT2) inhibitors in routine clinical practice.

DESIGN

Cohort study using data from nationwide registers and an active-comparator new-user design.

SETTING

Denmark, Norway, and Sweden, from April 2013 to December 2016.

PARTICIPANTS

20 983 new users of SGLT2 inhibitors and 20 983 new users of dipeptidyl peptidase 4 (DPP4) inhibitors, aged 35-84, matched by age, sex, history of major cardiovascular disease, and propensity score.

MAIN OUTCOME MEASURES

Primary outcomes were major cardiovascular events (composite of myocardial infarction, stroke, and cardiovascular death) and heart failure (hospital admission for heart failure or death due to heart failure). Secondary outcomes were the individual components of the cardiovascular composite and any cause death. In the primary analyses, patients were defined as exposed from treatment start throughout follow-up (analogous to intention to treat); additional analyses were conducted with an as-treated exposure definition. Cox regression was used to estimate hazard ratios.

RESULTS

Mean age of the study cohort was 61 years, 60% were men, and 19% had a history of major cardiovascular disease. Of the total 27 416 person years of follow-up in the SGLT2 inhibitor group, 22 627 (83%) was among patients who initiated dapagliflozin, 4521 (16%) among those who initiated empagliflozin, and 268 (1%) among those who initiated canagliflozin. During follow-up, 467 SGLT2 inhibitor users (incidence rate 17.0 events per 1000 person years) and 662 DPP4 inhibitor users (18.0) had a major cardiovascular event, whereas 130 (4.7) and 265 (7.1) had a heart failure event, respectively. Hazard ratios were 0.94 (95% confidence interval 0.84 to 1.06) for major cardiovascular events and 0.66 (0.53 to 0.81) for heart failure. Hazard ratios were consistent among subgroups of patients with and without history of major cardiovascular disease and with and without history of heart failure. Hazard ratios for secondary outcomes, comparing SGLT2 inhibitors with DPP4 inhibitors, were 0.99 (0.85 to 1.17) for myocardial infarction, 0.94 (0.77 to 1.15) for stroke, 0.84 (0.65 to 1.08) for cardiovascular death, and 0.80 (0.69 to 0.92) for any cause death. In the as-treated analyses, hazard ratios were 0.84 (0.72 to 0.98) for major cardiovascular events, 0.55 (0.42 to 0.73) for heart failure, 0.93 (0.76 to 1.14) for myocardial infarction, 0.83 (0.64 to 1.07) for stroke, 0.67 (0.49 to 0.93) for cardiovascular death, and 0.75 (0.61 to 0.91) for any cause death.

CONCLUSIONS

In this large Scandinavian cohort, SGLT2 inhibitor use compared with DPP4 inhibitor use was associated with reduced risk of heart failure and any cause death, but not with major cardiovascular events in the primary intention-to-treat analysis. In the additional as-treated analyses, the magnitude of the association with heart failure and any cause death became larger, and a reduced risk of major cardiovascular events that was largely driven by the cardiovascular death component was observed. These data help inform patients, practitioners, and authorities regarding the cardiovascular effectiveness of SGLT2 inhibitors in routine clinical practice.

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.