Renal hemodynamic effects of sodium-glucose cotransporter 2 inhibitors in hyperfiltering people with type 1 diabetes and people with type 2 diabetes and normal kidney function

Mechanisms of heart failure and chronic kidney disease protection by SGLT2 inhibitors in nondiabetic conditions

Sodium-glucose cotransporter 2 inhibitors (SGLT2is), initially developed for type 2 diabetes (T2D) treatment, have demonstrated significant cardiovascular and renal benefits in heart failure (HF) and chronic kidney disease (CKD), irrespective of T2D. This review provides an analysis of the multifaceted mechanisms underlying the cardiorenal benefits of SGLT2i in HF and CKD outside of the T2D context. Eight major aspects of the protective effects of SGLT2i beyond glycemic control are explored: 1) the impact on renal hemodynamics and tubuloglomerular feedback; 2) the natriuretic effects via proximal tubule Na+/H+ exchanger NHE3 inhibition; 3) the modulation of neurohumoral pathways with evidence of attenuated sympathetic activity; 4) the impact on erythropoiesis, not only in the context of local hypoxia but also systemic inflammation and iron regulation; 5) the uricosuria and mitigation of the hyperuricemic environment in cardiorenal syndromes; 6) the multiorgan metabolic reprogramming including the potential induction of a fasting-like state, improvement in glucose and insulin tolerance, and stimulation of lipolysis and ketogenesis; 7) the vascular endothelial growth factor A (VEGF-A) upregulation and angiogenesis, and 8) the direct cardiac effects. The intricate interplay between renal, neurohumoral, metabolic, and cardiac effects underscores the complexity of SGLT2i actions and provides valuable insights into their therapeutic implications for HF and CKD. Furthermore, this review sets the stage for future research to evaluate the individual contributions of these mechanisms in diverse clinical settings.

Identification of risk factors associated with acute kidney injury in patients taking sodium-glucose cotransporter-2 inhibitors

STUDY OBJECTIVE

Studies have demonstrated sodium-glucose cotransporter-2 (SGLT2) inhibitors are kidney protective; however, their ability to cause hemodynamic changes may predispose patients to acute kidney injury (AKI). An FDA warning recommends evaluating for factors that predispose patients to AKI before initiating a SGLT2 inhibitor. The primary objective of this study is to identify risk factors that may predispose persons with diabetes to AKI when initiating SGLT2 inhibitor therapy.

DESIGN

Multicenter retrospective cohort chart review.

DATA SOURCE

Study patients were identified through an electronic medical record generated report if they had type 2 diabetes and were prescribed a SGLT2 inhibitor from January 2013 to September 2019.

PATIENTS

Patients were included if they were receiving care at Advocate Medical Group and were confirmed to have taken one of the four SGLT2 inhibitors available at the time of study approval, canagliflozin, dapagliflozin, empagliflozin, or ertugliflozin, for at least 7 days. Patients were excluded if they did not have a basic metabolic panel or comprehensive metabolic panel recorded 1 year prior to or 6 months after SGLT2 inhibitor therapy initiation.

RESULTS

Data extraction from the electronic medical record identified 6425 patients receiving a SGLT2 inhibitor, of which 1962 met inclusion criteria and were included for analysis. Thirty-five (1.8%) patients experienced an AKI after SGLT2 inhibitor therapy initiation. There was no statistically significant difference between groups based on background medication use (p = 0.325). At baseline, patients experiencing an AKI after SGLT2 inhibitor initiation were more likely to be older in age (p = 0.010), have a higher serum potassium (p < 0.001), blood glucose (p = 0.018), SCr (p = 0.009) and UACR (p < 0.001), and a lower eGFR (p = 0.028) compared to those who did not experience AKI.

CONCLUSIONS

The transient eGFR decline with SGLT2 inhibitor initiation should be expected and is generally not an indication to discontinue therapy. Future initiatives should be directed at increasing knowledge of monitoring recommendations for these agents.

Interactive Effects of Empagliflozin and Hyperglycemia on Urinary Amino Acids in Individuals With Type 1 Diabetes

Optimizing energy use in the kidney is critical for normal kidney function. Here, we investigate the effect of hyperglycemia and sodium-glucose cotransporter 2 (SGLT2) inhibition on urinary amino acid excretion in individuals with type 1 diabetes (T1D). The open-label ATIRMA trial assessed the impact of 8 weeks of 25 mg empagliflozin orally once per day in 40 normotensive normoalbuminuric young adults with T1D. A consecutive 2-day assessment of clamped euglycemia and hyperglycemia was evaluated at baseline and posttreatment visits. Principal component analysis was performed on urinary amino acids grouped into representative metabolic pathways using MetaboAnalyst. At baseline, acute hyperglycemia was associated with changes in 25 of the 33 urinary amino acids or their metabolites. The most significant amino acid metabolites affected by acute hyperglycemia were 3-hydroxykynurenine, serotonin, glycyl-histidine, and nicotinic acid. The changes in amino acid metabolites were reflected by the induction of four biosynthetic pathways: aminoacyl-tRNA; valine, leucine, and isoleucine; arginine; and phenylalanine, tyrosine, and tryptophan. In acute hyperglycemia, empagliflozin significantly attenuated the increases in aminoacyl-tRNA biosynthesis and valine, leucine, and isoleucine biosynthesis. Our findings using amino acid metabolomics indicate that hyperglycemia stimulates biosynthetic pathways in T1D. SGLT2 inhibition may attenuate the increase in biosynthetic pathways to optimize kidney energy metabolism.

ARTICLE HIGHLIGHTS

Empagliflozin and Rapid Kidney Function Decline Incidence in Type 2 Diabetes: An Exploratory Analysis From the EMPA-REG OUTCOME Trial

Rationale & Objective

Kidney function progressively declines in most patients with type 2 diabetes (T2DM). Many develop progressive chronic kidney disease (CKD), but some experience a more rapid decline, with a greater risk of kidney failure and cardiovascular disease. In EMPA-REG OUTCOME, empagliflozin was associated with slower kidney disease progression. This post hoc analysis evaluated the effect of empagliflozin (pooled doses) on the prevalence of a "rapid decliner" phenotype, defined by an annual estimated glomerular filtration rate (eGFR) decline of >3 mL/min/1.73 m2.

Study Design

This was an exploratory analysis of EMPA-REG OUTCOME, a large randomized, double-blind, placebo-controlled trial in adults with T2DM, established cardiovascular disease and an eGFR of ≥30 mL/min/1.73 m2.

Setting & Participants

Analysis was undertaken on 6,967 participants (99.2%) in whom serial eGFR data was available.

Interventions

Patients were randomized (1:1:1) to empagliflozin 10 mg, 25 mg, or placebo in addition to standard of care.

Outcomes

Annual change in eGFR over the maintenance phase of treatment (week 4 to last value on treatment) was calculated using linear regression models. Logistic regression analysis was used to investigate differences in rapid decline between the treatment groups.

Results

Over the study period, a rapid decliner phenotype was observed in 188 (9.5%) participants receiving placebo and 134 (3.4%) receiving empagliflozin. After adjusting for other risk factors, this equated to a two-third reduction in odds (OR, 0.32; 95% CI, 0.25-0.40; P < 0.001) among participants receiving empagliflozin versus placebo. A comparable risk reduction was observed using a threshold of eGFR decline of >5 mL/min/1.73 m2/y (empagliflozin vs placebo, 43 [1.1%] vs 44 [2.2%] participants; OR, 0.47; 95% CI, 0.31-0.72; P < 0.001).

Limitations

This is a post hoc analysis of a trial undertaken in participants with T2DM and CVD. Generalization of findings to other settings remains to be established.

Conclusions

Patients receiving empagliflozin were significantly less likely to experience a rapid decline in eGFR over a median of 2.6 years of exposure to the study drug.

Funding

The Boehringer Ingelheim and Eli Lilly and Company Diabetes Alliance.

Trial Registration

clinicaltrials.gov ID: NCT01131676.

A Role for Sodium-Glucose Cotransporter 2 Inhibitors in the Treatment of Chronic Kidney Disease: A Mini Review

BACKGROUND

Sodium-glucose cotransport protein 2 (SGLT2) inhibitors, a new type of glucose-lowering drug, have been well proved in several clinical studies for their glucose-lowering and nephroprotective effects, and the nephroprotective effects include both indirect effects of metabolic improvement and direct effects, independent of glucose-lowering effects.

SUMMARY

In patients with diabetic kidney disease (DKD), several studies have demonstrated the potential nephroprotective mechanisms of SGLT2 inhibitors, and evidence of nephroprotective mechanisms in the non-DKD population is accumulating. Although the nephroprotective mechanism of SGLT2 inhibitors has not been fully elucidated, several laboratory studies have illustrated the mechanism underlying the effects of SGLT2 inhibitors at various aspects.

KEY MESSAGES

The purpose of this article is to review the mechanism of nephroprotective effect of SGLT2 inhibitors and to look forward to promising research in the future.

Intrarenal Mechanisms of Sodium-Glucose Cotransporter-2 Inhibitors on Tubuloglomerular Feedback and Natriuresis

When sodium-glucose cotransporter-2 (SGLT2) inhibitors were first introduced a decade ago, no one expected them to have substantial effects beyond their known glucose-lowering effects, until the emergence of evidence of their robust renal and cardiovascular benefits showing that they could attenuate progression of kidney disease, irrespective of diabetes, as well as prevent the development of acute kidney injury. Still, the precise and elaborate mechanisms underlying the major organ protection of SGLT2 inhibitors remain unclear. SGLT2 inhibitors inhibit the reabsorption of sodium and glucose in the proximal tubule of the kidney and then recovers tubuloglomerular feedback, whereby SGLT2 inhibitors reduce glomerular hyperfiltration. This simple demonstration of their beneficial effects has perplexed experts in seeking more plausible and as yet undisclosed explanations for the whole effects of SGLT2 inhibitors, including metabolism reprogramming and the modulation of hypoxia, inflammation, and oxidative stress. Given that the renal benefits of SGLT2 inhibitors in patients with kidney disease but without diabetes were comparable to those seen in patients with diabetes, it may be reasonable to keep the emphasis on their hemodynamic actions. In this context, the aim of the present review is to provide a comprehensive overview of renal hemodynamics in individuals with diabetes who are treated with SGLT2 inhibitors, with a focus on natriuresis associated with the regulation of tubuloglomerular feedback and potential aquaresis. Throughout the discussion of alterations in renal sodium and water transports, particular attention will be given to the potential enhancement of adenosine and its receptors following SGLT2 inhibition.

A profile of SGLT-2 inhibitors in hyponatremia: The evidence to date

Hyponatremia is the most common electrolyte disorder in clinical practice, which may lead to life-threatening complications. Several lines of evidence suggest that hyponatremia is associated not only with significant increases in length of stay, cost, and financial burden, but also with increased morbidity and mortality. Hyponatremia is also considered to be a negative prognostic factor in patients with heart failure and cancer. Although multiple therapeutic methods are available for treating hyponatremia, most have some limitations, such as poor compliance, rapid correction of serum Na⁺, other negative side effects and high cost. Given these limitations, identifying novel therapies for hyponatremia is essential. Recent clinical studies have shown that SGLT-2 inhibitors (SGLT 2i) significantly increased serum Na⁺ levels and were well tolerated by patients who underwent this treatment. Therefore, oral administration of SGLT 2i appears to be an effective treatment for hyponatremia. This article will briefly review the etiology of hyponatremia and integrated control of sodium within the kidney, current therapies for hyponatremia, potential mechanisms and efficacy of SGLT 2i for hyponatremia, and the benefits in cardiovascular, cancer, and kidney disease by regulating sodium and water balance.

Renal hemodynamic changes in patients with type 2 diabetes and their clinical impact

The dysfunction of the internal mechanics within the kidney's filtering units, known as glomeruli, has been linked to the emergence and progression of diabetic kidney disease (DKD). To better understand this crucial aspect of kidney function and the pathology of DKD, a variety of methods are employed in research, from the introduction of external compounds, such as inulin, iohexol, iothalamate and p-aminohippurate, to cutting-edge imaging techniques and computational analysis. Given the significance of intraglomerular hemodynamic dysfunction in the pathogenesis and treatment of DKD, it is essential to thoroughly examine the available data on this topic. Accordingly, the aim of this review is to provide a comprehensive appraisal of the role of intraglomerular hemodynamic dysfunction in the development of DKD and the effects of current therapies used to mitigate DKD. Through this analysis, we can gain a deeper understanding of the complex pathogenesis of DKD and potentially discover new avenues for tailored therapeutic management of patients with DKD.

Sodium-glucose cotransporter 1 inhibition and gout: Mendelian randomisation study

OBJECTIVE

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduce serum urate, but their efficacy depends on renal function which is often impaired in people with gout. SGLT1 is primarily expressed in the small intestine and its inhibition may be a more suitable therapeutic target. We aimed to investigate the association of genetically proxied SGLT1i with gout risk, serum urate levels and cardiovascular safety using Mendelian randomisation (MR).

METHODS

Leveraging data from a genome-wide association study of 344,182 individuals in the UK Biobank, we identified a missense variant in the SLC5A1 gene that associated with glycated haemoglobin (HbA1c) to proxy SGLT1i. Outcome genetic data comprised 13,179 gout cases and 750,634 controls, 457,690 individuals for serum urate levels, and up to 977,323 individuals for cardiovascular safety outcomes. We applied the Wald ratio method and investigated potential genetic confounding using colocalization.

RESULTS

The rs17683430 missense variant was selected to instrument SGLT1i. Genetically proxied SGLT1i was associated with 75% reduction in gout risk (OR 0.25; 95%CI 0.06, 0.99; p = 0.048) and 32.0 μmol/L reduction in serum urate (95%CI -56.7, -7.3; p = 0.01), per 6.7 mmol/mol reduction in HbA1c. SGLT1i was associated with increased levels of low-density lipoprotein cholesterol (0.37 mmol/L; 95%CI 0.17, 0.56; p = 0.0002) but not risk of coronary heart disease, stroke, or chronic kidney disease. Colocalization did not suggest that results are attributable to genetic confounding.

CONCLUSION

SGLT1 inhibition may represent a novel therapeutic option for preventing gout in people with or without comorbid diabetes. Randomised trials are needed to formally investigate efficacy and safety.

Emerging roles of Sodium-glucose cotransporter 2 inhibitors in Diabetic kidney disease

Diabetic kidney disease (DKD), a severe microvascular complication of diabetes mellitus, is the primary cause of end stage renal disease (ESRD). Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of novel anti-diabetic drugs for DKD, which have the potential to prevent renal function from failing. The involved mechanisms have garnered considerable attention. Besides hypoglycemic effect, it seems that various glucose-independent nephroprotective mechanisms also have a role. Among them, improvement in tubuloglomerular feedback is considered as the main reason, followed by reduced intraglomerular pressure and fluid load. In addition, reduced blood pressure, anti-inflammatory effects, nutrient deprivation signaling as well as improved endothelial function are also important. In the future, clinical trials and mechanistic studies might further complement the current knowledge on SGLT2 inhibitors and facilitate to translate these agents to clinical use. Here, we review these mechanisms of SGLT2 inhibitors with an emphasis on kidney protective effects.

Influence of Self-Practice Oriented Teaching plus Psychological Intervention on Blood Glucose Level and Psychological State in Patients with Type 2 Diabetes Mellitus on Insulin Therapy

Background. The study aimed to examine the effect of self-practice oriented teaching plus psychological intervention on blood glucose level and psychological status of type 2 diabetic patients on first insulin therapy. Methods. A total of 80 patients with type 2 diabetes admitted from April 2020 to November 2020 were assessed for eligibility and included. They were then assigned to a control group and an observation group via the random number table method, with 40 cases in each group. In addition to insulin injection treatment in both groups prior to intervention, the control group received health education and psychological intervention, whereas the observation group adopted a self-practice oriented teaching strategy plus psychological intervention. Insulin injections, nursing satisfaction, blood glucose level, and disease awareness were compared between the two groups. The Exercise of Self-Care Agency (ESCA) scale was used to assess the patients’ self-care ability, the Generic Quality of Life Inventory-74 (GQOLI-74) scale was used to assess their quality of life, and the emotional state of patients was evaluated by the Hospital Anxiety and Depression (HAD) scale. Results. Patients in the observation group outperformed the control group in terms of insulin injection after intervention ( $P<0.05$ ). Significantly higher nursing satisfaction and ESCA scores were observed after intervention ( $P<0.05$ ). Self-practice oriented teaching plus psychological intervention resulted in remarkably lower postintervention glycemic indexes ( $P<0.001$ ). Markedly higher disease knowledge scores and GQOLI-74 scores were witnessed in the observation group in contrast to those of the control group ( $P<0.001$ ). The observation group patients showed lower HAD scores than those of the control group ( $P<0.001$ ). Conclusion. Self-practice oriented teaching plus psychological intervention could effectively alleviate the negative emotions of type 2 diabetic patients on first insulin therapy, stabilize glycemic indexes, and improve quality of life, demonstrating good potential for clinical promotion.

Effects of Early Empagliflozin Initiation on Diuresis and Kidney Function in Patients With Acute Decompensated Heart Failure (EMPAG-HF)

BACKGROUND

Effective diuretic regimens using loop diuretics in patients with acute decompensated heart failure are often limited by the development of worsening kidney function. Sodium-glucose cotransporter-2 inhibitors induce glucosuria and sodium excretion with nephroprotective effects in patients with stable heart failure but their role in acute decompensated heart failure is unclear.

METHODS

In this single-center, prospective, double-blind, placebo-controlled, randomized study, we randomly assigned patients with acute decompensated heart failure to empagliflozin 25 mg daily or placebo in addition to standard decongestive treatments that included loop diuretics. The primary end point was cumulative urine output over 5 days. Secondary end points included diuretic efficiency, dynamics in markers of kidney function and injury, and NT-proBNP (N-terminal pro-B-type natriuretic peptide).

RESULTS

Sixty patients were randomized within 12 hours of hospitalization for acute decompensated heart failure. Addition of empagliflozin daily to standard medical treatment of acute decompensated heart failure resulted in a 25% increase in cumulative urine output over 5 days (median 10.8 versus 8.7 L mL in placebo, group difference estimation 2.2 L [95% CI, 8.4 to 3.6]; P=0.003). Empagliflozin increased diuretic efficiency compared with placebo (14.1 mL urine per milligram furosemide equivalent [95% CI, 0.6-27.7]; P=0.041) without affecting markers of renal function (estimated glomerular filtration rate, 51±19 versus 54±17 mL/min per 1.73 m²; P=0.599) or injury (total urinary protein, 492±845 versus 503±847 mg/g creatinine; P=0.975; and urinary α1-microglobulin, 55.4±38.6 versus 31.3±33.6 mg/g creatinine; P=0.066) with more pronounced decrease in NT-proBNP in the empagliflozin group compared with placebo (-1861 versus -727.2 pg/mL after 5 days; quotient in slope, 0.89 [95% CI, 0.83-0.95]; P<0.001). There were no differences in the incidence of safety events between groups.

CONCLUSIONS

Early addition of empagliflozin to standard diuretic therapy increases urine output without affecting renal function in patients with acute decompensated heart failure.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04049045.

Molecular Mechanisms and Therapeutic Targets for Diabetic Kidney Disease

Diabetic kidney disease has a high global disease burden and substantially increases risk of kidney failure and cardiovascular events. Despite treatment, there is substantial residual risk of disease progression with existing therapies. Therefore, there is an urgent need to better understand the molecular mechanisms driving diabetic kidney disease to help identify new therapies that slow progression and reduce associated risks. Diabetic kidney disease is initiated by diabetes-related disturbances in glucose metabolism, which then trigger other metabolic, hemodynamic, inflammatory, and fibrotic processes that contribute to disease progression. This review summarizes existing evidence on the molecular drivers of diabetic kidney disease onset and progression, focusing on inflammatory and fibrotic mediators-factors that are largely unaddressed as primary treatment targets and for which there is increasing evidence supporting key roles in the pathophysiology of diabetic kidney disease. Results from recent clinical trials highlight promising new drug therapies, as well as a role for dietary strategies, in treating diabetic kidney disease.

Sodium glucose cotransporter-2 inhibitors protect the cardiorenal axis: Update on recent mechanistic insights related to kidney physiology

Sodium glucose cotransporter-2 (SGLT2) inhibitors have acquired a central role in the treatment of type 2 diabetes, chronic kidney disease including diabetic kidney disease, and heart failure with reduced ejection fraction. SGLT2 inhibitors lower glucose levels by inducing glycosuria. In addition, SGLT2 inhibitors improve cardiovascular outcomes (3-point MACE), end-stage kidney disease, hospitalization for heart failure, and cardiovascular mortality in people with and without diabetes. The mechanisms underlying these benefits have been extensively investigated, but remain poorly understood. In this review, we first summarize recent trial evidence and subsequently focus on (1) the mechanisms by which SGLT2 inhibitors improve kidney outcomes and (2) the potential role of the kidneys in mediating the cardioprotective effects of SGLT2 inhibitors.

Relationship of Dapagliflozin With Serum Sodium: Findings From the DAPA-HF Trial

OBJECTIVES

This study aimed to assess the prognostic importance of hyponatremia and the effects of dapagliflozin on serum sodium in the DAPA-HF (Dapagliflozin And Prevention of Adverse outcomes in Heart Failure) trial.

BACKGROUND

Hyponatremia is common and prognostically important in hospitalized patients with heart failure with reduced ejection fraction, but its prevalence and importance in ambulatory patients are uncertain.

METHODS

We calculated the incidence of the primary outcome (cardiovascular death or worsening heart failure) and secondary outcomes according to sodium category (≤135 and >135 mmol/L). Additionally, we assessed: 1) whether baseline serum sodium modified the treatment effect of dapagliflozin; and 2) the effect of dapagliflozin on serum sodium.

RESULTS

Of 4,740 participants with a baseline measurement, 398 (8.4%) had sodium ≤135 mmol/L. Participants with hyponatremia were more likely to have diabetes, be treated with diuretics, and have lower systolic blood pressure, left ventricular ejection fraction, and estimated glomerular filtration rate. Hyponatremia was associated with worse outcomes even after adjustment for predictive variables (adjusted HRs for the primary outcome 1.50 [95% CI: 1.23-1.84] and all-cause death 1.59 [95% CI: 1.26-2.01]). The benefits of dapagliflozin were similar in patients with and without hyponatremia (HR for primary endpoint: 0.83 [95% CI: 0.57-1.19] and 0.73 [95% CI: 0.63-0.84], respectively, P for interaction = 0.54; HR for all-cause death: 0.85 [95% CI: 0.56-1.29] and 0.83 [95% CI: 0.70-0.98], respectively, P for interaction = 0.96). Between baseline and day 14, more patients on dapagliflozin developed hyponatremia (11.3% vs 9.4%; P = 0.04); thereafter, this pattern reversed and at 12 months fewer patients on dapagliflozin had hyponatremia (4.6% vs 6.7%; P = 0.003).

CONCLUSIONS

Baseline serum sodium concentration was prognostically important, but did not modify the benefits of dapagliflozin on morbidity and mortality in heart failure with reduced ejection fraction. (Study to Evaluate the Effect of Dapagliflozin on the Incidence of Worsening Heart Failure or Cardiovascular Death in Patients With Chronic Heart Failure [DAPA-HF]: NCT03036124).

Inhibition of sodium-glucose cotransporter 2 to slow the progression of chronic kidney disease

Chronic kidney disease (CKD) is a major public health problem, increasing the risk of cardiovascular events and death and potentially leading to kidney failure. Novel drugs that slow the progression of this non-communicable disease are therefore urgently needed. Initially developed as glucose-lowering drugs, inhibitors of the sodium-glucose cotransporter 2 (SGLT2) drastically reduce the overall mortality and cardiovascular events and slow the progression of CKD. Kidney protection conferred by SGLT2 inhibitors is independent from the presence of diabetes, observed on top of renin-angiotensin system inhibition and consistent across a wide range of categories of glomerular filtration rate and albuminuria. The mechanisms through which SGLT2 inhibitors improve kidney outcomes are likely multifactorial. Inhibition of SGLT2 in the kidney proximal tubule results in natriuresis and glucosuria, with beneficial effects on metabolic control, blood pressure and body weight. In addition, SGLT2 inhibitors also improve intraglomerular hemodynamics, podocyte integrity, cell metabolism, and erythropoiesis and reduce hypoxia, oxidative stress, sympathetic nervous activity, inflammation and fibrosis. The major impact of SGLT2 inhibitors on kidney outcomes, along with the excellent safety profile of this new class of drugs, open novel avenues for the treatment of CKD in patients with and without diabetes.

The Na/K-ATPase Signaling and SGLT2 Inhibitor-Mediated Cardiorenal Protection: A Crossed Road?

In different large-scale clinic outcome trials, sodium (Na⁺)/glucose co-transporter 2 (SGLT2) inhibitors showed profound cardiac- and renal-protective effects, making them revolutionary treatments for heart failure and kidney disease. Different theories are proposed according to the emerging protective effects other than the original purpose of glucose-lowering in diabetic patients. As the ATP-dependent primary ion transporter providing the Na⁺ gradient to drive other Na⁺-dependent transporters, the possible role of the sodium–potassium adenosine triphosphatase (Na/K-ATPase) as the primary ion transporter and its signaling function is not explored.

Renal haemodynamic and protective effects of renoactive drugs in type 2 diabetes: Interaction with SGLT2 inhibitors

Diabetic kidney disease remains the leading cause of end-stage kidney disease and a major risk factor for cardiovascular disease. Large cardiovascular outcome trials and dedicated kidney trials have shown that sodium-glucose cotransporter (SGLT)2 inhibitors reduce cardiovascular morbidity and mortality and attenuate hard renal outcomes in patients with type 2 diabetes (T2D). Underlying mechanisms explaining these renal benefits may be mediated by decreased glomerular hypertension, possibly by vasodilation of the post-glomerular arteriole. People with T2D often receive several different drugs, some of which could also impact the renal vasculature, and could therefore modify both renal efficacy and safety of SGLT2 inhibition. The most commonly prescribed drugs that could interact with SGLT2 inhibitors on renal haemodynamic function include renin-angiotensin system inhibitors, calcium channel blockers and diuretics. Herein, we review the effects of these drugs on renal haemodynamic function in people with T2D and focus on studies that measured glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) with gold-standard techniques. In addition, we posit, based on these observations, potential interactions with SGLT2 inhibitors with an emphasis on efficacy and safety.

SGLT2is and Renal Protection: From Biological Mechanisms to Real-World Clinical Benefits

In recent years, following the publication of results from several RCTs, first on cardiovascular and more recently on renal outcomes, SGLT2is have become the standard of care to prevent diabetic kidney disease and slow its progression. This narrative review focuses on biological mechanisms, both renal and extrarenal, underlying kidney protection with SGLT2is. Furthermore, data from cardiovascular as well as renal outcome trials, mostly conducted in diabetic patients, are presented and discussed to provide an overview of current uses as well as the future therapeutic potential of these drugs.

Angiotensin II up-regulates sodium-glucose co-transporter 2 expression and SGLT2 inhibitor attenuates Ang II-induced hypertensive renal injury in mice

Clinical trials indicate that sodium/glucose co-transporter 2 (SGLT2) inhibitors (SGLT2i) improve kidney function, yet, the molecular regulation of SGLT2 expression is incompletely understood. Here, we investigated the role of the intrarenal renin-angiotensin system (RAS) on SGLT2 expression. In adult non-diabetic participants in the Nephrotic Syndrome Study Network (NEPTUNE, n=163), multivariable linear regression analysis showed SGLT2 mRNA was significantly associated with angiotensinogen (AGT), renin, and angiotensin-converting enzyme (ACE) mRNA levels (P<0.001). In vitro, angiotensin II (Ang II) dose-dependently stimulated SGLT2 expression in HK-2, human immortalized renal proximal tubular cells (RPTCs); losartan and antioxidants inhibited it. Sglt2 expression was increased in transgenic (Tg) mice specifically overexpressing Agt in their RPTCs, as well as in WT mice with a single subcutaneous injection of Ang II (1.44 mg/kg). Moreover, Ang II (1000 ng/kg/min) infusion via osmotic mini-pump in WT mice for 4 weeks increased systolic blood pressure (SBP), glomerulosclerosis, tubulointerstitial fibrosis, and albuminuria; canaglifozin (Cana, 15 mg/kg/day) reversed these changes, with the exception of SBP. Fractional glucose excretion (FeGlu) was higher in Ang II+Cana than WT+Cana, whereas Sglt2 expression was similar. Our data demonstrate a link between intrarenal RAS and SGLT2 expression and that SGLT2i ameliorates Ang II-induced renal injury independent of SBP.

A kidney perspective on the mechanism of action of sodium glucose co-transporter 2 inhibitors

Sodium glucose co-transporter (SGLT) 2 inhibitors reduce the risk of kidney failure in patients with and without type 2 diabetes (T2D). Although the precise underlying mechanisms for these nephroprotective effects are incompletely understood, various hypotheses have been proposed including reductions in intraglomerular pressure through restoration of tubuloglomerular feedback, blood pressure reduction and favorable effects on vascular function, reduction in tubular workload and hypoxia, and metabolic effects resulting in increased autophagy. Here, we review these mechanisms, which may also explain the beneficial effects of SGLT2 inhibitors on kidney function in patients without T2D.

Cardiorenal Protection in Diabetic Kidney Disease

Over the last 5 years there have been many new developments in the management of diabetic kidney disease. Glucagon-like peptide-1 receptor agonists (GLP-1 RA) and sodium-glucose cotransporter-2 (SGLT2) inhibitors were initially used for glycemic control, but more recent studies have now shown that their benefits extend to cardiovascular and kidney outcomes. The recent addition of data on the novel mineralocorticoid receptor antagonist (MRA) gives us another approach to further decrease the residual risk of diabetic kidney disease progression. In this review we describe the mechanism of action, key studies, and possible adverse effects related to these three classes of medications. The management of type 2 diabetes now includes an increasing number of medications for the management of comorbidities in a patient population at significant risk of cardiovascular disease and progression of chronic kidney disease. It is from this perspective that we seek to outline the rationale for the sequential and/or combined use of SGLT2 inhibitors, GLP-1 RA and MRAs in patients with type 2 diabetes for heart and kidney protection.

Efficacy of Dapagliflozin on Renal Function and Outcomes in Patients With Heart Failure With Reduced Ejection Fraction: Results of DAPA-HF

Supplemental Digital Content is available in the text.

Many patients with heart failure and reduced ejection fraction (HFrEF) have chronic kidney disease that complicates pharmacological management and is associated with worse outcomes. We assessed the safety and efficacy of dapagliflozin in patients with HFrEF, according to baseline kidney function, in the DAPA-HF trial (Dapagliflozin and Prevention of Adverse-outcomes in Heart Failure). We also examined the effect of dapagliflozin on kidney function after randomization.

Making a case for the combined use of SGLT2 inhibitors and GLP1 receptor agonists for cardiorenal protection

Sodium glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RA) were initially approved to improve glycemic control in the treatment of type 2 diabetes. Clinical trials have also demonstrated beneficial effects with regards to cardiovascular and renal parameters. Beyond improving glycemic control, these therapies promote weight loss and lower blood pressure when used individually, and in an additive manner when used together. Accordingly, taking advantage of complementary mechanisms of action with the combined use of these two classes of agents to further improve cardiorenal outcomes is conceptually appealing, but has yet to be explored in detail in clinical trials. In this review, we discuss proposed mechanisms for renal protection, clinical benefits, and adverse events associated with the individual and combined use of SGLT2 inhibitors and GLP-1RA. The management of type 2 diabetes has significantly changed over the last few years, moving away from solely glycemic control towards the concurrent management of associated comorbidities in a patient population at significant risk of cardiovascular disease and progression of chronic kidney disease. It is from this perspective that we seek to outline the rationale for the sequential and/or combined use of SGLT2 inhibitors and GLP-1RA in patients with type 2 diabetes.

Epigenetic Modifiers as Potential Therapeutic Targets in Diabetic Kidney Disease

Diabetic kidney disease is one of the fastest growing causes of death worldwide. Epigenetic regulators control gene expression and are potential therapeutic targets. There is functional interventional evidence for a role of DNA methylation and the histone post-translational modifications-histone methylation, acetylation and crotonylation-in the pathogenesis of kidney disease, including diabetic kidney disease. Readers of epigenetic marks, such as bromodomain and extra terminal (BET) proteins, are also therapeutic targets. Thus, the BD2 selective BET inhibitor apabetalone was the first epigenetic regulator to undergo phase-3 clinical trials in diabetic kidney disease with an endpoint of kidney function. The direct therapeutic modulation of epigenetic features is possible through pharmacological modulators of the specific enzymes involved and through the therapeutic use of the required substrates. Of further interest is the characterization of potential indirect effects of nephroprotective drugs on epigenetic regulation. Thus, SGLT2 inhibitors increase the circulating and tissue levels of β-hydroxybutyrate, a molecule that generates a specific histone modification, β-hydroxybutyrylation, which has been associated with the beneficial health effects of fasting. To what extent this impact on epigenetic regulation may underlie or contribute to the so-far unclear molecular mechanisms of cardio- and nephroprotection offered by SGLT2 inhibitors merits further in-depth studies.