SGLT2 inhibitors and the kidney: Effects and mechanisms

Effect of dapagliflozin on the serum metabolome in patients with type 2 diabetes mellitus

Objectives

SGLT-2 inhibitors have been shown to exert cardio- and renoprotective actions. We aimed to investigate the underlying mechanisms using 1H-NMR based metabolomics in patients with type-2 diabetes mellitus who received dapagliflozin.

Methods

50 patients with type 2 diabetes mellitus, inadequately controlled on metformin monotherapy (HbA1c > 7%) received dapagliflozin for 3 months and 30 matched patients received insulin degludec for 3 months. Clinical and laboratory values, as well as 1H-NMR based metabolomics were assessed before treatment and after completion of 3 months of treatment.

Results

Dapagliflozin reduced weight, body mass index, systolic and diastolic blood pressure significantly. Using 1H-NMR based metabolomics, the dapagliflozin group showed a good separation with a degree of overlap before and after treatment initiation. Regarding targeted metabolomics, dapagliflozin increased serum ketone, citrate and tryptophan levels compared with insulin. On the other hand, serum taurine, threonine and mannose levels were significantly decreased following dapagliflozin administration.

Conclusions

Dapagliflozin led to a small, but significant change in serum metabolome. The observed changes may indicate improvement in energy metabolism, reduction in inflammatory activity and decreased insulin resistance which may provide further evidence of the agent's observed cardiac and renal protection. The study was registered with ClinicalTrials.gov (identifier: NCT02798757).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01508-1.

Long-term effect of sodium-glucose cotransporter 2 inhibitors in kidney functions: A systematic review and meta-analysis

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors (such as dapagliflozin, empagliflozin, and canagliflozin) are essential for the treatment of type 2 diabetes because they improve the urine excretion of glucose. Although there are advantages, including weight loss and enhanced heart health, caution is necessary because of possible negative effects, such as higher urine output and euglycemic diabetic ketoacidosis. They may slow chronic kidney disease progression, therefore, renal function must be monitored. This study aims to determine the efficacy of SGLT2 inhibitors in the prevention of renal deterioration in terms of reduction of estimated glomerular filtration rate (eGFR) in patients with compromised renal functions.

METHODS

This study aimed to document the long-term effects of SGLT2 inhibitors on kidney function. PubMed and Google Scholar were the key sources of scholarly publications, and Boolean operators were used to perform exact searches. Nine articles were considered relevant out of a total of 244, following extensive screening of titles, abstracts, and full texts according to PRISMA recommendations.

RESULTS

This study included randomized, double-blind, placebo-controlled trials evaluating the long-term effects of SGLT2 inhibitors on renal function across patient demographics and locations. Clinical investigations showed different effects on eGFR across control and study groups, suggesting renal protection. A meta-analysis showed that SGLT2 inhibitors enhanced kidney function more than the controls.

CONCLUSION

This meta-analysis concluded that SGLT2 inhibitors have the potential to prevent eGFR reduction and improve renal function in patients with compromised renal function and underlying conditions such as chronic kidney disease or type 1 and 2 diabetes. However, this meta-analysis showed beneficial results in the prevention of renal deterioration within several follow-up periods, with an average of 11 to 12 months.

Sodium-Glucose Cotransporter 2 Inhibitors in Diabetic Kidney Disease and beyond

Background

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have significantly impacted the management of diabetic kidney disease (DKD) and heart failure (HF), providing benefits beyond glycemic control. This review examines the mechanisms through which SGLT2is provide renal and cardiovascular protection and assesses their clinical efficacy.

Summary

By inducing glucosuria and natriuresis, SGLT2is alleviate multiple complications induced by chronic hyperglycemia. Moreover, SGLT2is reduce albuminuria, improve tubular function, and modulate erythropoiesis. Additionally, they mitigate inflammation and fibrosis by decreasing oxidative stress and downregulating proinflammatory pathways. Clinical trials have demonstrated significant reductions in renal and cardiovascular events among patients with type 2 diabetes mellitus. A comprehensive review of the literature was conducted through PubMed, highlighting the effects of SGLT2is and the results of major clinical trials involving SGLT2is.

Key Messages

SGLT2is play a crucial role in the management of DKD and HF by addressing multiple pathogenic pathways. Currently, SGLT2is are included in clinical guidelines for DKD and HF management, and their benefits extend to nondiabetic populations. Further research is needed to explore SGLT2is' multifaceted mechanisms and potential applications across diverse patient populations and different disease etiologies.

EValuating the Effect of periopeRaTIve empaGliflOzin on cardiac surgery associated acute kidney injury: rationale and design of the VERTIGO study

Background

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a serious complication in patients undergoing cardiac surgery with extracorporeal circulation (ECC) that increases postoperative complications and mortality. CSA-AKI develops due to a combination of patient- and surgery-related risk factors that enhance renal ischemia-reperfusion injury. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin reduce renal glucose reabsorption, improving tubulo-glomerular feedback, reducing inflammation and decreasing intraglomerular pressure. Preclinical studies have observed that SGLT2i may provide significant protection against renal ischemia-reperfusion injury due to their effects on inadequate mitochondrial function, reactive oxygen species activity or renal peritubular capillary congestion, all hallmarks of CSA-AKI. The VERTIGO (EValuating the Effect of periopeRaTIve empaGliflOzin) trial is a Phase 3, investigator-initiated, randomized, double-blind, placebo-controlled, multicenter study that aims to explore whether empagliflozin can reduce the incidence of adverse renal outcomes in cardiac surgery patients.

Methods

The VERTIGO study (EudraCT: 2021-004938-11) will enroll 608 patients that require elective cardiac surgery with ECC. Patients will be randomly assigned in a 1:1 ratio to receive either empagliflozin 10 mg orally daily or placebo. Study treatment will start 5 days before surgery and will continue during the first 7 days postoperatively. All participants will receive standard care according to local practice guidelines. The primary endpoint of the study will be the proportion of patients that develop major adverse kidney events during the first 90 days after surgery, defined as ≥25% renal function decline, renal replacement therapy initiation or death. Secondary, tertiary and safety endpoints will include rates of AKI during index hospitalization, postoperative complications and observed adverse events.

Conclusions

The VERTIGO trial will describe the efficacy and safety of empagliflozin in preventing CSA-AKI. Patient recruitment is expected to start in May 2024.

The effect of renal function on the pharmacokinetics and pharmacodynamics of enavogliflozin, a potent and selective sodium-glucose cotransporter-2 inhibitor, in type 2 diabetes

AIMS

To explore the effect of renal function on the pharmacokinetic (PK) and pharmacodynamic (PD) profile and safety of enavogliflozin, a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes mellitus (T2DM).

METHODS

An open-label, two-part clinical trial was conducted in T2DM patients, stratified by renal function: Group 1, normal renal function; Group 2, mild renal impairment (RI); Group 3, moderate RI; and Group 4, severe RI. In Part A, Groups 2 and 4 received enavogliflozin 0.5 mg once. In Part B, Groups 1 and 3 received enavogliflozin 0.5 mg once daily for 7 days. Serial blood and timed urine samples were collected to analyse the PK and PD characteristics of enavogliflozin. Pearson's correlation coefficients were calculated to assess the correlations between PK or PD parameters and creatinine clearance (CrCL).

RESULTS

A total of 21 patients completed the study as planned. The area under the curve (AUC) for enavogliflozin was not significantly correlated with CrCL, although the maximum concentration slightly decreased as renal function decreased. By contrast, daily urinary glucose excretion (UGE) was positively correlated with CrCL after both single- (r = 0.7866, p < 0.0001) and multiple-dose administration (r = 0.6606, p = 0.0438).

CONCLUSIONS

Systemic exposure to oral enavogliflozin 0.5 mg was similar among the patients with T2DM regardless of their renal function levels. However, the glucosuric effect of enavogliflozin decreased with RI. Considering the UGE observed and approved therapeutic use of other SGLT2 inhibitors, the efficacy of enavogliflozin with regard to glycaemic control could be explored in patients with mild and moderate RI (estimated glomerular filtration rate ≥30 or ≥45 mL/min/1.73 m2) in a subsequent larger study.

Narrative review investigating the nephroprotective mechanisms of sodium glucose cotransporter type 2 inhibitors in diabetic and nondiabetic patients with chronic kidney disease

Background and aims

Outcome trials using sodium glucose cotransporter type 2 inhibitors have consistently shown their potential to preserve kidney function in diabetic and nondiabetic patients. Several mechanisms have been introduced which may explain the nephroprotective effect of sodium glucose cotransporter type 2 inhibitors beyond lowering blood glucose. This current narrative review has the objective to describe main underlying mechanisms causing a nephroprotective effect and to show similarities as well as differences between proposed mechanisms which can be observed in patients with diabetic and nondiabetic chronic kidney disease.

Methods

We performed a narrative review of the literature on Pubmed and Embase. The research string comprised various combinations of items including "chronic kidney disease", "sodium glucose cotransporter 2 inhibitor" and "mechanisms". We searched for original research and review articles published until march, 2022. The databases were searched independently and the agreements by two authors were jointly obtained.

Results

Sodium glucose cotransporter type 2 inhibitors show systemic, hemodynamic, and metabolic effects. Systemic effects include reduction of blood pressure without compensatory activation of the sympathetic nervous system. Hemodynamic effects include restoration of tubuloglomerular feedback which may improve pathologic hyperfiltration observed in most cases with chronic kidney disease. Current literature indicates that SGLT2i may not improve cortical oxygenation and may reduce medullar oxygenation.

Conclusion

Sodium glucose cotransporter type 2 inhibitors cause nephroprotective effects by several mechanisms. However, several mediators which are involved in the underlying pathophysiology may be different between diabetic and nondiabetic patients.

Comparison of SGLT1, SGLT2, and Dual Inhibitor biological activity in treating Type 2 Diabetes Mellitus

Diabetes Mellitus Type 2 (T2D) is an emerging health burden in the USand worldwide, impacting approximately 15% of Americans. Current front-line therapeutics for T2D patients include sulfonylureas that act to reduce A1C and/or fasting blood glucose levels, or Metformin that antagonizes the action of glucagon to reduce hepatic glucose production. Next generation glucomodulatory therapeutics target members of the high-affinity glucose transporter Sodium-Glucose-Linked-Transporter (SGLT) family. SGLT1 is primarily expressed in intestinal epithelium, whose inhibition reduces dietary glucose uptake, whilst SGLT2 is highly expressed in kidney - regulating glucose reabsorption. A number of SGLT2 inhibitors are FDA approved whilst SGLT1 and dual SGLT1 & 2 inhibitor are currently in clinical trials. Here, we discuss and compare SGLT2, SGLT1, and dual inhibitors' biochemical mechanism and physiological effects.

Pharmacokinetic and pharmacodynamic interaction of DWP16001, a sodium-glucose cotransporter 2 inhibitor, with gemigliptin and metformin in healthy adults

AIMS

DWP16001, a novel sodium-glucose cotransporter 2 inhibitor, is under clinical development for the treatment of type 2 diabetes mellitus. This study aimed to explore the pharmacokinetics (PK) and pharmacodynamics interaction of DWP16001 with gemigliptin and metformin.

METHODS

A randomized, open-label, 2-sequence, 2-period crossover study was conducted in 34 healthy male subjects. All subjects received a single oral dose of DWP16001 2 mg with and without gemigliptin and metformin (8 days of 50 mg once-daily dose and 1000 mg twice daily dose for gemigliptin and metformin, respectively). Serial blood samples were collected for PK and serum glucose analysis, and timed urine samples were collected to analyse urine glucose excretion (UGE). The PK and pharmacodynamic parameters were analysed by the noncompartmental method.

RESULTS

The PK interactions of DWP16001, gemigliptin and metformin were not clinically significant. The geometric mean ratios (with 90% confidence intervals) of coadministration to separate administration for area under the time-concentration curves were 1.04 (1.02-1.06), 1.03 (0.98-1.09) and 1.17 (1.12-1.22), for gemigliptin, metformin and DWP16001 respectively. The UGE induced by DWP16001 was not affected by the coadministration of gemigliptin and metformin.

CONCLUSION

The results suggest that the DWP16001 could be added to metformin and gemigliptin combination therapy without dose adjustment.

Cardiovascular and renal efficacy and safety of sodium-glucose cotransporter-2 inhibitors in patients without diabetes: a systematic review and meta-analysis of randomised placebo-controlled trials

OBJECTIVES

To assess the cardiovascular and renal efficacy and safety of sodium-glucose cotransporter-2 (SGLT2) inhibitors in patients without diabetes.

METHODS

We searched PubMed, MEDLINE, Embase and Cochrane Library for publications up to 17 August 2022. Certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. Random-effects meta-analyses were performed to pool effect measures across studies. Risk ratios (RRs) with 95% CIs are expressed for composite cardiovascular outcome of cardiovascular death or hospitalisation for heart failure, cardiovascular death, hospitalisation for heart failure, all-cause mortality and composite renal outcome of ≥50% reduction in estimated glomerular filtration rate (eGFR), end-stage kidney disease or renal death. Annual rate of change in eGFR is expressed as the mean difference with 95% CI.

RESULTS

We identified four trials with 8927 patients with heart failure or chronic kidney disease (CKD). Compared with placebo, SGLT2 inhibitors showed favourable effects on the composite cardiovascular outcome (RR: 0.79, 95% CI: 0.71 to 0.87; moderate certainty), cardiovascular death (0.85, 0.74 to 0.99; moderate certainty), hospitalisation for heart failure (0.72, 0.62 to 0.82; moderate certainty), the composite renal outcome (0.64, 0.48 to 0.85; low certainty) and the annual rate of change in eGFR (mean difference: 0.99, 0.59 to 1.39 mL/min/1.73 m²/year; moderate certainty), while there was no significant difference in all-cause mortality (0.88, 0.77 to 1.01; very low certainty). Moderate certainty evidence indicated that SGLT2 inhibitors reduced the risk of serious adverse events and acute renal failure. Low certainty evidence suggested that SGLT2 inhibitors increased the risk of urinary tract infection and genital infection, while there were no differences in discontinuation due to adverse events, amputation, fracture, hypoglycaemia, ketoacidosis or volume depletion.

CONCLUSIONS

Evidence of low to moderate certainty suggests that SGLT2 inhibitors provide cardiorenal benefits but have increased risk for urinary tract infection and genital infection in patients without diabetes and with heart failure or CKD.

PROSPERO REGISTRATION NUMBER

CRD42021239807.

Changes in Proximal Tubular Reabsorption Modulate Microvascular Regulation via the TGF System

This review paper considers the consequences of modulating tubular reabsorption proximal to the macula densa by sodium–glucose co-transporter 2 (SGLT2) inhibitors, acetazolamide, and furosemide in states of glomerular hyperfiltration. SGLT2 inhibitors improve renal function in early and advanced diabetic nephropathy by decreasing the glomerular filtration rate (GFR), presumably by activating the tubuloglomerular feedback (TGF) mechanism. Central in this paper is that the renoprotective effects of SGLT2 inhibitors in diabetic nephropathy can only be partially explained by TGF activation, and there are alternative explanations. The sustained activation of TGF leans on two prerequisites: no or only partial adaptation should occur in reabsorption proximal to macula densa, and no or only partial adaptation should occur in the TGF response. The main proximal tubular and loop of Henle sodium transporters are sodium–hydrogen exchanger 3 (NHE3), SGLT2, and the Na-K-2Cl co-transporter (NKCC2). SGLT2 inhibitors, acetazolamide, and furosemide are the most important compounds; inhibiting these transporters would decrease sodium reabsorption upstream of the macula densa and increase TGF activity. This could directly or indirectly affect TGF responsiveness, which could oppose sustained TGF activation. Only SGLT2 inhibitors can sustainably activate the TGF as there is only partial compensation in tubular reabsorption and TGF response. SGLT2 inhibitors have been shown to preserve GFR in both early and advanced diabetic nephropathy. Other than for early diabetic nephropathy, a solid physiological basis for these effects in advanced nephropathy is lacking. In addition, TGF has hardly been studied in humans, and therefore this role of TGF remains elusive. This review also considers alternative explanations for the renoprotective effects of SGLT2 inhibitors in diabetic patients such as the enhancement of microvascular network function. Furthermore, combination use of SGLT2 inhibitors and angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs). in diabetes can decrease inflammatory pathways, improve renal oxygenation, and delay the progression of diabetic nephropathy.

Clin-Star corner: What is new at the interface of geriatrics and nephrology?

Chronic kidney disease (CKD) is prevalent and burdensome among older adults in the United States. CKD affects at least 15% of the US population, and adults over 65 comprise the largest subset within this group. In this special article, we highlight key findings of three recent original investigations in nephrology and describe each study, relevance to the care of older adults, and current areas of uncertainty that warrant further investigation. Articles relate to removal of the race adjustment in the estimation of kidney function, the use of novel therapeutics to halt CKD progression and improve cardiovascular outcomes, and medication management for short-term pain control in CKD.

circ_000166/miR-296 Aggravates the Process of Diabetic Renal Fibrosis by Regulating the SGLT2 Signaling Pathway in Renal Tubular Epithelial Cells

Diabetic renal fibrosis is a common cause of end-stage renal disease, and the circRNA-miRNA-mRNA network may play an important role in the progression of diabetic nephropathy- (DN-) induced renal fibrosis. In this study, the role of circ_000166/miR-296/SGLT2 in the process of DN-related renal fibrosis was studied by constructing an animal model of DN renal fibrosis via lentiviral transfection, plasmid transfection, and dual-luciferase reporting techniques. Compared with that of normal controls, the expression of circ_000166 in the kidney tissues of DN renal fibrosis mice substantially increased. Silencing circ_000166 could minimize kidney damage and decrease urine protein levels, thereby inhibiting the progression of renal fibrosis. Moreover, circ_000166 could act as the ceRNA of miR-296 and competitively bind to miR-296, leading to an increase in the expression of the SGLT2 gene regulated by miR-296. Through mutual verification via in vivo and in vitro experiments, miR-296 was overexpressed and SGLT2 was silenced. Results showed that DN renal fibrosis and cell apoptosis were considerably reduced. We postulate that circ_000166/miR-296/SGLT2 may become a new target in the progression of DN renal fibrosis, and the regulation of this pathway may be a promising strategy for clinical treatment of DN renal fibrosis.

Cardiovascular benefit of SGLT2 inhibitors

Patients with type 2 diabetes mellitus (T2D) are at increased risk of cardiovascular (CV) disease. Sodium glucose cotransporter 2 (SGLT2) inhibitors, also known as gliflozins, are a class of medications used to treat T2D by preventing the reabsorption of glucose filtered through the kidney and thereby facilitating glucose excretion in the urine. Over the past 5 years, many cardiovascular outcome trials (CVOTs) have evaluated the safety and efficacy of SGLT2 inhibitors in preventing CV events. The results of 7 CVOTs have provided solid evidence that the use of SGLT2 in patients with T2D and at high CV risk significantly reduced the risk of death from CV causes. Moreover, in patient with heart failure with reduced ejection fraction, regardless of the presence or absence of T2D, SGLT2 inhibitors use significantly reduced the risk of worsening heart failure and death from CV causes. Although the exact mechanism of the cardiorenal benefit of SGLT2 inhibitors is still unknown, studies have shown that the beneficial effect of these drugs cannot be exclusively explained by their glucose lowering effect, and several possible mechanisms have been proposed. This review will explore the changing role of SGLT2 inhibitors from a diabetes drug to clinical practice guideline-supported therapy for the prevention and treatment of CV diseases, including heart failure.

Potential kidney protection with liraglutide and semaglutide: Exploratory mediation analysis

AIMS

To investigate whether effects on chronic kidney disease risk factors could explain the apparent reduction in kidney outcomes (composite of macroalbuminuria, doubling of serum creatinine, renal replacement therapy, or renal death), primarily driven by changes in albuminuria, after treatment with the glucagon-like peptide-1 receptor agonists (GLP-1RAs) liraglutide and semaglutide in patients with type 2 diabetes in the LEADER and SUSTAIN 6 trials.

MATERIALS AND METHODS

We evaluated the mediation effect of glycated haemoglobin (HbA1c), systolic blood pressure (BP), and body weight on the kidney effects of GLP-1RAs. Diastolic BP, haemoglobin, heart rate, low-density lipoprotein and total cholesterol, and white blood cell count were also investigated. The mediation effect was estimated by the novel Vansteelandt statistical method. Subgroups with estimated glomerular filtration rate (eGFR) <60 and ≥60 mL/min/1.73 m² were examined in LEADER.

RESULTS

We observed that HbA1c mediated 25% (95% confidence interval [CI] -7.1; 67.3) and 26% (95% CI noncalculable), and systolic BP 9% (95% CI 2.8; 22.7) and 22% (95% CI noncalculable) of kidney effects of GLP-1RAs in LEADER and SUSTAIN 6, respectively. Small or no mediation was observed for the other parameters; for example, body weight mediated 9% (95% CI -7.9; 35.5) in the former and did not mediate effects in the latter study. Mediation by HbA1c was greater in patients with eGFR ≥60 mL/min/1.73 m² (57%) versus those with eGFR <60 mL/min/1.73 m² (no mediation).

CONCLUSIONS

Our results suggest that HbA1c and systolic BP may moderately mediate kidney benefits of liraglutide and semaglutide, with all other variables having a small to no effect. Potential kidney benefits may be driven by other mediators or potentially by direct mechanisms.

The Effect of Dapagliflozin on Albuminuria in DECLARE-TIMI 58

OBJECTIVE

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve albuminuria in patients with high cardiorenal risk. We report albuminuria change in the Dapagliflozin Effect on Cardiovascular Events (DECLARE-TIMI 58) cardiovascular outcome trial, which included populations with lower cardiorenal risk.

RESEARCH DESIGN AND METHODS

DECLARE-TIMI 58 randomized 17,160 patients with type 2 diabetes, creatinine clearance >60 mL/min, and either atherosclerotic cardiovascular disease (CVD; 40.6%) or risk-factors for CVD (59.4%) to dapagliflozin or placebo. Urinary albumin-to-creatinine ratio (UACR) was tested at baseline, 6 months, 12 months, and yearly thereafter. The change in UACR over time was measured as a continuous and categorical variable (≤15, >15 to <30, ≥30 to ≤300, and >300 mg/g) by treatment arm. The composite cardiorenal outcome was a ≥40% sustained decline in the estimated glomerular filtration rate (eGFR) to <60 mL/min/1.73 m², end-stage kidney disease, and cardiovascular or renal death; specific renal outcome included all except cardiovascular death.

RESULTS

Baseline UACR was available for 16,843 (98.15%) participants: 9,067 (53.83%) with ≤15 mg/g, 2,577 (15.30%) with >15 to <30 mg/g, 4,030 (23.93%) with 30-300 mg/g, and 1,169 (6.94%) with >300 mg/g. Measured as a continuous variable, UACR improved from baseline to 4.0 years with dapagliflozin, compared with placebo, across all UACR and eGFR categories (all P < 0.0001). Sustained confirmed ≥1 category improvement in UACR was more common in dapagliflozin versus placebo (hazard ratio 1.45 [95% CI 1.35-1.56], P < 0.0001). Cardiorenal outcome was reduced with dapagliflozin for subgroups of UACR ≥30 mg/g (P < 0.0125, P _interaction = 0.033), and the renal-specific outcome was reduced for all UACR subgroups (P < 0.05, P _interaction = 0.480).

CONCLUSIONS

In DECLARE-TIMI 58, dapagliflozin demonstrated a favorable effect on UACR and renal-specific outcome across baseline UACR categories, including patients with normal albumin excretion. The results suggest a role for SGLT2i also in the primary prevention of diabetic kidney disease.

Effects of sodium-glucose cotransporter type 2 inhibitors on cardiovascular, renal, and safety outcomes in patients with cardiovascular disease: a meta-analysis of randomized controlled trials

Background

Controlled studies and observational studies have shown that sodium-glucose cotransporter type 2 inhibitors (SGLT-2i) are beneficial for the survival of patients with heart failure (HF). However, it is unclear whether SGLT-2i can provide benefit in patients with other cardiovascular diseases. Here, we conducted a systematic review and meta-analysis to determine the outcomes of cardiovascular, renal, and safety outcomes of SGLT-2i administration in patients with cardiovascular diseases.

Methods

We searched PubMed, EMBASE, Cochrane Library, Web of Science databases, and ClinicalTrials.gov databases for randomised controlled trials written in English from inception until November 1, 2020. Two reviewers independently identified randomised controlled trials comparing the effects of SGLT-2i in patients with cardiovascular disease with or without diabetes. Primary outcomes were cardiovascular outcomes and renal outcomes. Secondary outcomes were safety outcomes, including adverse endocrine outcomes and adverse infection outcomes. The effects of SGLT-2i were evaluated using RevMan5.3 software. The Cochrane risk of bias tool was used to assess study quality.

Results

We identified 10 randomised controlled trials (25,108 patients in the SGLT-2i group and 18,574 patients in the placebo group). Meta-analysis revealed that SGLT-2i treatment significantly reduced all-cause mortality, cardiovascular mortality, and hospitalisation for heart failure (HHF) in patients with cardiovascular disease (all-cause mortality relative risk [RR]: 0.86; 95% confidence interval [CI] 0.81–0.91; P < 0.00001; I² = 0%; cardiovascular mortality RR: 0.85; 95% CI 0.79–0.92; P < 0.0001; I² = 26%; HHF RR: 0.69; 95% CI 0.64–0.81; P < 0.00001; I² = 0%). In patients with HF, mortality and HHF after SGLT-2i treatment for HF with reduced ejection fraction were significantly reduced, whereas HF with preserved ejection fraction did not differ compared with placebo treatment. Moreover, SGLT-2i induced a lower incidence of renal damage and myocardial infarction than the placebo group; however, the risk of infection, amputation, volume depletion, and diabetic ketoacidosis was higher.

Conclusions

SGLT-2i had significant clinical effects on cardiovascular outcomes and significantly influenced acute kidney injury. The effects of SGLT-2i on cardiovascular disease were independent of diabetic status. Sotagliflozin could have advantages over other SGLT-2i in lowering HHF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01272-z.

Kidney Disease in Type 2 Diabetes Mellitus and Benefits of Sodium-Glucose Cotransporter 2 Inhibitors: A Consensus Statement

Diabetic kidney disease (DKD) occurs in approximately 20-40% of patients with type 2 diabetes mellitus. Patients with DKD have a higher risk of cardiovascular and all-cause mortality. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and antihyperglycemic drugs form the mainstay of DKD management and aim to restrict progression to more severe stages of DKD. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) control hyperglycemia by blocking renal glucose reabsorption in addition to preventing inflammation, thereby improving endothelial function and reducing oxidative stress; consequently, this class of prescription medicines is emerging as an important addition to the therapeutic armamentarium. The EMPA-REG OUTCOME, DECLARE TIMI 58, and CANVAS trials demonstrated the renoprotective effects of SGLT2i, such as restricting decline in glomerular filtration rate, in the progression of albuminuria, and in death due to renal causes. The renoprotection provided by SGLT2i was further confirmed in the CREDENCE study, which showed a 30% reduction in progression of chronic kidney disease, and in the DELIGHT study, which demonstrated a reduction in albuminuria with dapagliflozin compared with placebo (- 21.0%, confidence interval [CI] - 34.1 to - 5.2, p = 0.011). Furthermore, a meta-analysis demonstrated a reduced risk of dialysis, transplantation, or death due to kidney disease (relative risk 0.67; 95% CI 0.52-0.86; p = 0.0019) and a 45% risk reduction in worsening of renal function, end-stage renal disease, or renal death (hazard ratio 0.55, CI 0.48-0.64, p < 0.0001) with SGLT2i, irrespective of baseline estimated glomerular filtration rate. Thus, there is emerging evidence that SGLT2i may be used to curb the mortality and improve the quality of life in patients with DKD. However, clinicians need to effectively select candidates for SGLT2i therapy. In this consensus statement, we have qualitatively synthesized evidence demonstrating the renal effects of SGLT2i and proposed recommendations for optimal use of SGLT2i to effectively manage and delay progression of DKD.

Novel therapeutic agents for the treatment of diabetic kidney disease

INTRODUCTION

Diabetic kidney disease (DKD) involves multifaceted pathophysiology which increases the risk of cardiorenal events and mortality. Conventional therapy is limited to renin-angiotensin aldosterone system inhibition and management of hyperglycemia and hypertension. Recent clinical trials have demonstrated promising nephroprotective effects of antihyperglycemic agents thus modifying guideline treatment recommendations for type 2 diabetic patients with chronic kidney disease.

AREAS OF COVERED

Relevant studies and clinical trials were searched via PubMed and clinicaltrials.gov through August 2020. Authors offer an update on clinical evidence regarding nephroprotective effects and side effects of sodium-glucose-cotransporter-2 (SGLT2) inhibitors, glucagon-like-peptide-1 (GLP1) agonists and dipeptidylpeptidase-4 (DPP4) inhibitors. They discuss the potential benefits of novel therapy targeting DKD pathogenic processes including inflammation, oxidative stress, fibrosis, and vasoconstriction shown in early phases of clinical trials and offer an opinion on key challenges and directions for future progress.

EXPERT OPINION

SGLT2 inhibitors are the most promising agents for DKD and improving cardiorenal outcomes. Mineralocorticoid-receptor antagonists and janus kinase inhibitors are also promising investigational therapies that target oxidative stress, nitric oxide synthesis, and inflammation. Novel therapeutic targets and the identification of clinically useful biomarkers may provide future therapies that detect early stages of DKD enabling a slower kidney function decline.

Sodium-glucose cotransporter 2 inhibitors: extending the indication to non-diabetic kidney disease?

This year the medical community was pleasantly surprised by the results of the first large outcome trial that primarily examined the renal effects of the sodium-glucose cotransporter 2 (SGLT2) inhibitor canagliflozin (CANA) in subjects with diabetes and impaired kidney function. The Evaluation of the Effects of Canagliflozin on Renal and Cardiovascular Outcomes in Participants With Diabetic Nephropathy (CREDENCE) trial showed that CANA, relative to placebo, reduces the risk for end-stage renal disease, doubling of creatinine or renal death by 34% [hazard ratio 0.66 (95% confidence interval 0.53–0.81]. These effects were consistent across baseline estimated glomerular filtration rate (eGFR) and haemoglobin A1c subgroups. In this review we combine the results of the CREDENCE trial with those of several cardiovascular outcome trials with SGLT2 inhibitors and show that, unexpectedly, patients with lower eGFR levels may have greater benefit with respect to cardiovascular outcome than patients with normal kidney function. The cardio- and renoprotective effects of SGLT2 inhibitors seem to be independent of their glucose-lowering effects, as shown in several post hoc analyses. In this review we discuss the alleged mechanisms of action that explain the beneficial effects of this novel class of drugs. Moreover, we discuss whether these findings indicate that this class of drugs may also be beneficial in non-diabetic chronic kidney diseases.

Glifozines and cardiorenal outcomes

Diabetes mellitus, with its complications, is one of the major health problems in economically developed countries and its prevalence is constantly increasing. Kidneys and heart involvement represent main comorbidities in diabetic patients often leading to organ failure. The treatments available until a few years ago are often associated with hypoglycemia, weight gain, gastro-intestinal disorders and other side effects together with serious adverse effects on renal function. The new frontiers of diabetic cardionephropathy treatment are mainly focused on delay of heart and renal failure both on diabetic and nondiabetic patients ad it was shown by last data reports. In the following review, we will focus on Gliflozins, one of the newest classes of hypoglycemic drugs that have shown to hold peculiar pharmacological properties in managing cardiac and renal complications.

Importance of sodium-glucose cotransporter 2 inhibitor use in diabetic patients with acute heart failure

BACKGROUND

It is known that once heart failure occurs in older patients with diabetes, the overall prognosis is extremely poor. We investigated whether early initiation of SGLT2 inhibitor therapy after admission was beneficial for diabetic patients requiring inpatient treatment for acute heart failure.

METHODS

We retrospectively assessed consecutive patients with comorbid diabetes who were admitted to the Department of Cardiology in Tosei General Hospital for treatment of acute heart failure. Patients were divided into two groups: those who initiated SGLT2 inhibitor therapy (SGLT2 inhibitor group; mean age: 73 ± 9 years) and those who did not receive the inhibitors during hospitalization (conventional treatment group; mean age: 75 ± 10 years).

RESULTS

No intergroup differences were observed in the distribution of either the severity or classes of heart failure on admission. Glycosylated hemoglobin levels were significantly higher in the SGLT2 inhibitor group (HbA1c: 8.1% ± 0.8%) than in the conventional treatment group (HbA1c: 7.1% ± 0.8%) (p = 0.003). After admission, patients in both groups recovered equally well, and in almost the same period of time, before discharge. The rate of diuretics use at the time of discharge in the SGLT2 inhibitor group (n = 8, 67%) was significantly lower than that in the conventional treatment group (n = 19, 100%) (p = 0.016). In particular, the dose of loop diuretics in the conventional treatment group was 34 ± 4 mg/day while that in the SGLT2 inhibitor group was significantly lower at 13 ± 5 mg/day (p = 0.008). During hospitalization, the incidence of acute kidney injury was significantly higher in the conventional treatment group (n = 11, 58%) than in the SGLT2 inhibitor group (n = 2, 16%) (p = 0.031).

CONCLUSIONS

For the treatment and management of heart failure in patients with diabetes, early initiation of SGLT2 inhibitor therapy appears to be effective.

Mitochondrial DNA: A New Predictor of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a common cause of end-stage renal disease, and diagnosis and treatment in time can help delay its progress. At present, there are more and more studies on the pathogenesis of DKD; mitochondrial dysfunction plays an important role in DKD. The occurrence and development of DKD is closely related to epigenetic changes and the interaction between mtDNA, ROS, inflammatory factors, and endothelial damage, which continuously aggravates kidney. The change of mtDNA is both the cause of DKD and the result of DKD. It is of great significance to incorporate the change of mtDNA into the monitoring of patients with diabetes. Existing evidence indicates that changes in mtDNA copy number in blood and urine reflect mitochondrial dysfunction and the severity of DKD. However, large-scale, long-term follow-up clinical trials are still needed to determine the threshold range. By the time, mitochondrial-targeted antioxidants will become a new method for the treatment of DKD and other diabetic complications; mtDNA also can be a therapeutic target for them.

Endothelial Toxicity of High Glucose and its by-Products in Diabetic Kidney Disease

Alterations of renal endothelial cells play a crucial role in the initiation and progression of diabetic kidney disease. High glucose per se, as well as glucose by-products, induce endothelial dysfunction in both large vessels and the microvasculature. Toxic glucose by-products include advanced glycation end products (AGEs), a group of modified proteins and/or lipids that become glycated after exposure to sugars, and glucose metabolites produced via the polyol pathway. These glucose-related endothelio-toxins notably induce an alteration of the glomerular filtration barrier by increasing the permeability of glomerular endothelial cells, altering endothelial glycocalyx, and finally, inducing endothelial cell apoptosis. The glomerular endothelial dysfunction results in albuminuria. In addition, high glucose and by-products impair the endothelial repair capacities by reducing the number and function of endothelial progenitor cells. In this review, we summarize the mechanisms of renal endothelial toxicity of high glucose/glucose by-products, which encompass changes in synthesis of growth factors like TGF-β and VEGF, induction of oxidative stress and inflammation, and reduction of NO bioavailability. We finally present potential therapies to reduce endothelial dysfunction in diabetic kidney disease.

What Next After Metformin? Thinking Beyond Glycaemia: Are SGLT2 Inhibitors the Answer?

The prevalence of type 2 diabetes continues to increase, along with a proliferation of glucose-lowering treatment options. There is universal agreement in the clinical community for the use of metformin as the first-line glucose-lowering therapy for the majority of patients. However, controversy exists regarding the choice of second-line therapy once metformin is no longer effective. The most recent treatment consensus focuses on the presence of cardiovascular disease, heart failure or kidney disease as a determinant of therapy choice. The majority of patients in routine practice, however, do not fall into such categories. Heart failure and kidney disease represent significant clinical and cost considerations in patients with type 2 diabetes and have a close pathophysiological association. Recent data has illustrated that sodium-glucose transporter 2 (SGLT2) inhibitor therapy can reduce the burden of heart failure and the progression of renal disease across a wide range of patients including those with and without established disease, supported by an increased understanding of the mechanistic effects of these agents. Furthermore, there is growing evidence to illustrate the overall safety profile of this class of agents and support the benefit-risk profile of SGLT2 inhibitors as a preferred option following metformin monotherapy failure, with respect to both kidney disease progression and heart failure outcomes.

Appraisal of Non-Cardiovascular Safety for Sodium-Glucose Co-Transporter 2 Inhibitors: A Systematic Review and Meta-Analysis of Placebo-Controlled Randomized Clinical Trials

Background: Whereas the cardiovascular safety of sodium-glucose co-transporter 2 (SGLT2) inhibitors has been well reported, there is limited data from controlled clinical trials regarding the non-cardiovascular safety. This was the focus of our study.

Methods and Findings: We systematically searched MEDLINE, EMBASE, and Cochrane Library (5^th Sep 2018) for randomized controlled trials (RCTs) that reported safety data for SGLT2 inhibitors and placebo. Relative risks (RRs) and their 95% confidence intervals (CIs) were pooled using random-effects models. Seventy RCTs (83 studies enrolling 36,958 patients in 78 publications) were identified. SGLT2 inhibitors were associated with a lower risk of serious adverse events (RR 0.90, 95% CI 0.86 to 0.94, P < 0.001), death (RR 0.78, 95% CI 0.64 to 0.94, P < 0.05), gastroenteritis (RR 0.38, 95% CI 0.20 to 0.72, P < 0.05), arthralgia (RR 0.72, 95% CI 0.54 to 0.96, P < 0.05), hypertension (RR 0.61, 95% CI 0.50 to 0.75, P < 0.001), and edema/peripheral edema (RR 0.49, 95% CI 0.33 to 0.72, P < 0.001) compared to placebo. SGLT2 inhibitors were associated with higher risk of infections compared to placebo (RR 1.27, 95% CI 1.17 to 1.37, P < 0.001), especially for genital mycotic infection (GMI) (RR 3.71, 95% CI 3.19 to 4.32, P < 0.001). Other significant effects were observed for osmotic diuresis–related AEs (RR 2.73, 95% CI 2.20 to 3.40, P < 0.001), volume-related AEs (RR 1.26, 95% CI 1.08 to 1.46, P < 0.05), renal-related AEs (RR 1.36, 95% CI 1.02 to 1.80, P < 0.05), hypoglycemia (RR 1.18, 95% CI 1.10 to 1.26, P < 0.001), and increased blood ketone bodies (RR 2.00, 95% CI 1.01 to 3.97, P < 0.05). Subgroup and sensitivity analyses strengthened the robustness of primary results.

Conclusion: Results from RCTs confirmed lower risk of death, serious adverse events, hypertension, and edema associated with type 2 diabetes mellitus (T2DM) patients treated with SGLT2 inhibitors when compared with placebo. The use of SGLT2 inhibitors were associated with higher risk of infection, osmotic diuresis, volume depletion effects, renal related AEs, and higher blood ketone bodies when compared with placebo.

Differential pharmacology and clinical utility of dapagliflozin in type 2 diabetes

Dapagliflozin belongs in the family of sodium-glucose cotransporter 2 (SGLT2) inhibitors and acts by reducing glucose reabsorption in the proximal tubule. The aim of this review is to present the differential pharmacology and clinical utility of dapagliflozin. Dapagliflozin is orally administered, has a long half-life of 12.9 hours and (similar to empagliflozin) is a much weaker SGLT1 inhibitor compared with canagliflozin. Dapagliflozin significantly decreases glycated hemoglobin and fasting glucose levels in patients with type 2 diabetes mellitus (T2DM). The drug improves body weight, blood pressure, uric acid, triglycerides and high-density lipoprotein cholesterol. In the DECLARE-TIMI 58 trial, a large trial of 17,160 T2DM patients with established cardiovascular disease (CVD) or without established CVD but with multiple risk factors, dapagliflozin compared with placebo resulted in a significantly lower rate of the composite outcome of CVD death or hospitalization for heart failure (HHF); this effect was mainly due to a lower rate of HHF in the dapagliflozin group (HR: 0.73; 95%CI: 0.61–0.88), whereas no difference was observed in the rate of CVD death (HR: 0.98; 95%CI: 0.82–1.17). Moreover, dapagliflozin was noninferior to placebo with respect to major adverse CVD events. Dapagliflozin exerts beneficial effects on albuminuria. Additionally, in the DECLARE-TIMI 58 trial it significantly reduced the composite renal endpoint (40% decrease in glomerular filtration rate, end stage renal disease, or renal death) in both patients with established CVD and patients with multiple risk factors (overall HR: 0.53; 95%CI: 0.43–0.66). However dapagliflozin, like the other SGLT2 inhibitors, is associated with an increased risk of genital and urinary tract infections (usually mild mycotic infections) and acute kidney injury in cases of reduced extracellular volume. Dapagliflozin is a useful antidiabetic treatment which also exerts beneficial effects in the management of heart failure and diabetic kidney disease.

Improved home BP profile with dapagliflozin is associated with amelioration of albuminuria in Japanese patients with diabetic nephropathy: the Yokohama add-on inhibitory efficacy of dapagliflozin on albuminuria in Japanese patients with type 2 diabetes study (Y-AIDA study)

Background

The Y-AIDA study was designed to investigate the renal- and home blood pressure (BP)-modulating effects of add-on dapagliflozin treatment in Japanese individuals with type 2 diabetes mellitus (T2DM) and albuminuria.

Methods

We conducted a prospective, multicenter, single-arm study. Eighty-six patients with T2DM, HbA1c 7.0–10.0%, estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m², and urine albumin-to-creatinine ratio (UACR) ≥ 30 mg/g creatinine (gCr) were enrolled, and 85 of these patients were administered add-on dapagliflozin for 24 weeks. The primary and key secondary endpoints were change from baseline in the natural logarithm of UACR over 24 weeks and change in home BP profile at week 24.

Results

Baseline median UACR was 181.5 mg/gCr (interquartile range 47.85, 638.0). Baseline morning, evening, and nocturnal home systolic/diastolic BP was 137.6/82.7 mmHg, 136.1/79.3 mmHg, and 125.4/74.1 mmHg, respectively. After 24 weeks, the logarithm of UACR decreased by 0.37 ± 0.73 (P < 0.001). In addition, changes in morning, evening, and nocturnal home BP from baseline were as follows: morning systolic/diastolic BP − 8.32 ± 11.42/− 4.18 ± 5.91 mmHg (both P < 0.001), evening systolic/diastolic BP − 9.57 ± 12.08/− 4.48 ± 6.45 mmHg (both P < 0.001), and nocturnal systolic/diastolic BP − 2.38 ± 7.82/− 1.17 ± 5.39 mmHg (P = 0.0079 for systolic BP, P = 0.0415 for diastolic BP). Furthermore, the reduction in UACR after 24 weeks significantly correlated with an improvement in home BP profile, but not with changes in other variables, including office BP. Multivariate linear regression analysis also revealed that the change in morning home systolic BP was a significant contributor to the change in log-UACR.

Conclusions

In Japanese patients with T2DM and diabetic nephropathy, dapagliflozin significantly improved albuminuria levels and the home BP profile. Improved morning home systolic BP was associated with albuminuria reduction.

Trial registration The study is registered at the UMIN Clinical Trials Registry (UMIN000018930; http://www.umin.ac.jp/ctr/index-j.htm). The study was conducted from July 1, 2015 to August 1, 2018.

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0912-3) contains supplementary material, which is available to authorized users.

SGLT1 inhibition: Pros and cons

Sodium Glucose Cotransporters 1 (SGLT1) play important roles in the intestinal absorption of glucose and the renal reabsorption of glucose, especially in patients with uncontrolled diabetes and those receiving SGLT2 inhibitors. As a consequence, the inhibition of SGLT1 transporters may represent an interesting therapeutic option in patients with diabetes. However, genetic models of SGLT1 inactivation indicate that the malfunction of these transporters may have adverse effects on various tissues. In this review, we discuss the available evidence on the beneficial and detrimental effects that the inhibition of SGLT1 transporters might have. The inhibition of SGLT1 lowers serum glucose levels through the inhibition of intestinal absorption and renal reabsorption of glucose. In addition, drugs that interfere with SGLT1-mediated transport of glucose may protect cardiac tissue by reducing glycogen accumulation and decreasing the production of reactive oxygen species. On the other hand, this strategy may result in diarrhea, volume depletion, may interfere with the correction of hypoglycemia through the oral administration of carbohydrates and could predispose to the development of euglycemic diabetic ketoacidosis. Therefore, at the moment, SGLT1 inhibition seems to represent a two-edged sword.

Glycemic control by the SGLT2 inhibitor empagliflozin decreases aortic stiffness, renal resistivity index and kidney injury

Background

Arterial stiffness is emerging as an independent risk factor for the development of chronic kidney disease. The sodium glucose co-transporter 2 (SGLT2) inhibitors, which lower serum glucose by inhibiting SGLT2-mediated glucose reabsorption in renal proximal tubules, have shown promise in reducing arterial stiffness and the risk of cardiovascular and kidney disease in individuals with type 2 diabetes mellitus. Since hyperglycemia contributes to arterial stiffness, we hypothesized that the SGLT2 inhibitor empagliflozin (EMPA) would improve endothelial function, reduce aortic stiffness, and attenuate kidney disease by lowering hyperglycemia in type 2 diabetic female mice (db/db).

Materials/methods

Ten-week-old female wild-type control (C57BLKS/J) and db/db (BKS.Cg-Dock7m+/+Leprdb/J) mice were divided into three groups: lean untreated controls (CkC, n = 17), untreated db/db (DbC, n = 19) and EMPA-treated db/db mice (DbE, n = 19). EMPA was mixed with normal mouse chow at a concentration to deliver 10 mg kg⁻¹ day⁻¹, and fed for 5 weeks, initiated at 11 weeks of age.

Results

Compared to CkC, DbC showed increased glucose levels, blood pressure, aortic and endothelial cell stiffness, and impaired endothelium-dependent vasorelaxation. Furthermore, DbC exhibited impaired activation of endothelial nitric oxide synthase, increased renal resistivity and pulsatility indexes, enhanced renal expression of advanced glycation end products, and periarterial and tubulointerstitial fibrosis. EMPA promoted glycosuria and blunted these vascular and renal impairments, without affecting increases in blood pressure. In addition, expression of “reversion inducing cysteine rich protein with Kazal motifs” (RECK), an anti-fibrotic mediator, was significantly suppressed in DbC kidneys and partially restored by EMPA. Confirming the in vivo data, EMPA reversed high glucose-induced RECK suppression in human proximal tubule cells.

Conclusions

Empagliflozin ameliorates kidney injury in type 2 diabetic female mice by promoting glycosuria, and possibly by reducing systemic and renal artery stiffness, and reversing RECK suppression.