SGLT-2 inhibitors in nephrotic-range proteinuria: emerging clinical evidence

The effects of Tripterygium wilfordii Hook F on renal outcomes in type 2 diabetic kidney disease patients with severe proteinuria: a single-center cohort study

AIM

Tripterygium wilfordii Hook F (TwHF) has been shown to substantially reduce proteinuria in patients with diabetic kidney disease (DKD); however, the effect of TwHF on renal outcomes in DKD remains unknown. Accordingly, we aimed to establish the effects of TwHF on renal outcomes in patients with DKD.

METHODS

Overall, 124 patients with DKD, induced by type 2 diabetes mellitus, with 24-h proteinuria > 2 g, and an estimated glomerular filtration rate > 30 mL/min/1.73 m2 were retrospectively investigated. The renal outcomes were defined as doubling serum creatinine levels or end-stage kidney disease. Kaplan-Meier curves and Cox regression analyses were performed to analyze prognostic factors for renal outcomes.

RESULTS

By the end of the follow-up, renal outcomes were observed in 23 and 11 patients in the non-TwHF and TwHF groups, respectively (p = 0.006). TwHF significantly reduced the risk of renal outcomes (adjusted hazard ratio [HR] 0.271, 95% confidence interval [CI] 0.111-0.660, p = 0.004) in patients with chronic kidney disease (CKD) G3 (adjusted HR 0.274, 95%CI 0.081-0.932, p = 0.039). Based on the Kaplan-Meier analysis, 1- and 3-year proportions of patients without renal outcomes were significantly lower in the non-TwHF group than those in the TwHF group (92.8% vs. 95.5% and 47.2% vs. 76.8%, respectively; p = 0.0018).

CONCLUSION

In DKD patients with severe proteinuria, TwHF could prevent DKD progression, especially in patients with CKD G3. A randomized clinical trial is needed to elucidate the benefits of TwHF on renal outcomes in patients with DKD.

Apical tubular complement activation and the loss of kidney function in proteinuric kidney diseases

Many kidney diseases are associated with proteinuria. Since proteinuria is independently associated with kidney function loss, anti-proteinuric medication, often in combination with dietary salt restriction, comprises a major cornerstone in the prevention of progressive kidney failure. Nevertheless, complete remission of proteinuria is very difficult to achieve, and most patients with persistent proteinuria slowly progress toward kidney failure. It is well-recognized that proteinuria leads to kidney inflammation and fibrosis via various mechanisms. Among others, complement activation at the apical side of the proximal tubular epithelial cells is suggested to play a crucial role as a cause of progressive loss of kidney function. However, hitherto limited attention is given to the pathophysiological role of tubular complement activation relative to glomerular complement activation. This review aims to summarize the evidence for tubular epithelial complement activation in proteinuric kidney diseases in relation to loss of kidney function.

Drug repurposing for glomerular diseases: an underutilized resource

Drug repurposing in glomerular disease can deliver opportunities for steroid-free regimens, enable personalized multi-target options for resistant or relapsing disease and enhance treatment options for understudied populations (for example, children) and in resource-limited settings. Identification of drug-repurposing candidates can be data driven, which utilizes existing data on disease pathobiology, drug features and clinical outcomes, or experimental, which involves high-throughput drug screens. Information from databases of approved drugs, clinical trials and PubMed registries suggests that at least 96 drugs on the market cover 49 targets with immunosuppressive potential that could be candidates for drug repurposing in glomerular disease. Furthermore, evidence to support drug repurposing is available for 191 immune drug target-glomerular disease pairs. Non-immunological drug repurposing includes strategies to reduce haemodynamic overload, podocyte injury and kidney fibrosis. Recommended strategies to expand drug-repurposing capacity in glomerular disease include enriching drug databases with glomeruli-specific information, enhancing the accessibility of primary clinical trial data, biomarker discovery to improve participant selection into clinical trials and improve surrogate outcomes and initiatives to reduce patent, regulatory and organizational hurdles.

Proximal tubule hypertrophy and hyperfunction: a novel pathophysiological feature in disease states

The role of proximal tubules (PTs), a major component of the renal tubular structure in the renal cortex, has been examined extensively. Along with its physiological role in the reabsorption of various molecules, including electrolytes, amino acids and monosaccharides, transcellular transport of different hormones and regulation of homeostasis, pathological events affecting PTs may underlie multiple disease states. PT hypertrophy or a hyperfunctioning state, despite being a compensatory mechanism at first in response to various stimuli or alterations at tubular transport proteins, have been shown to be critical pathophysiological events leading to multiple disorders, including diabetes mellitus, obesity, metabolic syndrome and congestive heart failure. Moreover, pharmacotherapeutic agents have primarily targeted PTs, including sodium-glucose cotransporter 2, urate transporters and carbonic anhydrase enzymes. In this narrative review, we focus on the physiological role of PTs in healthy states and the current understanding of the PT pathologies leading to disease states and potential therapeutic targets.

Clinical value of adding Dapagliflozin in patients with nephrotic syndrome

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors in nephrotic patients on immunosuppression are underexplored. We evaluated dapagliflozin's impact in non-diabetic primary nephrotic syndrome.

METHODS

Randomized controlled clinical trial was conducted on 60 non-diabetic primary nephrotic syndrome patients, equally assigned to dapagliflozin and control groups. All patients received the standard of care medication and the Dapagliflozin group received 10 mg dapagliflozin in addition. Demographic data, nephrotic syndrome etiology, proteinuria levels, eGFR, and immunosuppression doses, were well-matched. After 6 months of follow up primary outcomes included changes in and eGFR.

RESULTS

Both groups exhibited significant reductions in proteinuria after 6 months, with the dapagliflozin group achieving a mean UPCR reduction of  - 94.7%, and the control group  - 86.7% (p < 0.001). However, the comparative change in proteinuria between both groups did not reach statistical significance (p = 0.158). Dapagliflozin initially led to a transient eGFR decline. Dapagliflozin also resulted in a significant mean body weight reduction (p < 0.001) and notable improvements in triglyceride levels compared to the control group (p = 0.045).

CONCLUSION

In primary nephrotic syndrome patients, adjunct dapagliflozin may enhance the standard of care. While notable, the reduction in proteinuria was comparable to that of the control group by the study's end. Furthermore, after 6 months, eGFR remained stable in both groups. However, significant weight loss and serum triglyceride reduction were particularly pronounced in the dapagliflozin group. Further long-term investigations are necessary to address potential immunosuppression-related confounding effects in patients with primary glomerular disease.

Diabetic Nephropathy, Retinopathy, and Functional Hypogonadism in a Patient with MODY10: A Case Report

(1) Background and objectives: Maturity-onset diabetes of the young (MODY) is a group of diabetes caused by gene defects related to insulin secretion. MODY1, MODY2, and MODY3 are the most common and account for approximately 80% of all cases. Other types are relatively rare. This study describes the clinical, analytical, and genetic characteristics of a patient with MODY10, and diabetic nephropathy, retinopathy, and functional hypogonadism diagnosis. (2) Materials and methods: A clinical case was analyzed and whole exome generation sequencing (WES) was used to detect mutations related to a monogenic variant. (3) Results: A seventeen-year-old male patient, who was diagnosed with apparent type 1 diabetes at the age of eight was started with insulin therapy. He came to the emergency room with glycemic decompensation, facial, and lower limb edema. During his evaluation, he had near-nephrotic range proteinuria of 2902 mg/24 h, a kidney ultrasound showing mild pyelocalyceal dilation, proliferative diabetic retinopathy, and was also diagnosed with functional hypogonadotropic hypogonadism. These comorbidities improved with adequate glycemic control. WES showed missense variant c.94G>A (p.Gly32Ser) in the INS gene, according to Clinvar corresponding to MODY10. It was a "de novo" variant not reported in his parents. (4) Conclusions: Monogenic diabetes (MD) is rare and MODY10 is among the less frequent types. MODY should be suspected in patients with type 1 phenotype with negative autoimmunity even in the absence of a family history of diabetes. To the best of our knowledge, we present here the first patient with these phenotypic traits of MODY10 reported in Latin America.

Sodium-Glucose Co-Transporter 2 Inhibitors: Mechanism of Action and Efficacy in Non-Diabetic Kidney Disease from Bench to Bed-Side

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are currently available for the management of type 2 diabetes mellitus. SGLT2i acts by inhibiting renal SGLT2, thereby increasing glucosuria and lowering serum glucose. Recent trials are emerging supporting a role for SGLT2i irrespective of the diabetic status pointing towards that SGLT2i have other mechanisms of actions beyond blood sugar control. In this review, we will shed light on the role of this group of medications that act as SGLT2i in non-diabetics focusing on pre-clinical and clinical data highlighting the mechanism of renoprotection and effects of SGLT2i in the non-diabetic kidneys.

Risks and Benefits of SGLT-2 Inhibitors for Type 1 Diabetes Patients Using Automated Insulin Delivery Systems-A Literature Review

The primary treatment for autoimmune Diabetes Mellitus (Type 1 Diabetes Mellitus-T1DM) is insulin therapy. Unfortunately, a multitude of clinical cases has demonstrated that the use of insulin as a sole therapeutic intervention fails to address all issues comprehensively. Therefore, non-insulin adjunct treatment has been investigated and shown successful results in clinical trials. Various hypoglycemia-inducing drugs such as Metformin, glucagon-like peptide 1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, amylin analogs, and Sodium-Glucose Cotransporters 2 (SGLT-2) inhibitors, developed good outcomes in patients with T1DM. Currently, SGLT-2 inhibitors have remarkably improved the treatment of patients with diabetes by preventing cardiovascular events, heart failure hospitalization, and progression of renal disease. However, their pharmacological potential has not been explored enough. Thus, the substantial interest in SGLT-2 inhibitors (SGLT-2is) underlines the present review. It begins with an overview of carrier-mediated cellular glucose uptake, evidencing the insulin-independent transport system contribution to glucose homeostasis and the essential roles of Sodium-Glucose Cotransporters 1 and 2. Then, the pharmacological properties of SGLT-2is are detailed, leading to potential applications in treating T1DM patients with automated insulin delivery (AID) systems. Results from several studies demonstrated improvements in glycemic control, an increase in Time in Range (TIR), a decrease in glycemic variability, reduced daily insulin requirements without increasing hyperglycemic events, and benefits in weight management. However, these advantages are counterbalanced by increased risks, particularly concerning Diabetic Ketoacidosis (DKA). Several clinical trials reported a higher incidence of DKA when patients with T1DM received SGLT-2 inhibitors such as Sotagliflozin and Empagliflozin. On the other hand, patients with T1DM and a body mass index (BMI) of ≥27 kg/m2 treated with Dapagliflozin showed similar reduction in hyperglycemia and body weight and insignificantly increased DKA incidence compared to the overall trial population. Additional multicenter and randomized studies are required to establish safer and more effective long-term strategies based on patient selection, education, and continuous ketone body monitoring for optimal integration of SGLT-2 inhibitors into T1DM therapeutic protocol.

Is there any robust evidence showing that SGLT2 inhibitor predisposes to cancer?

BACKGROUND

The exact pathophysiological mechanisms of SGLT-2 inhibitors in the development, progression or treatment of malignancies are not fully understood, but multiple hypotheses have been proposed. SGLT-2 inhibitors have potential anti-proliferative roles due to several underlying pathophysiological mechanisms, such as inhibition of ATP production, activation of AMPK signalling, induction of apoptosis and ferroptosis, inhibition of glutamate dehydrogenase activity and inhibition of DNA and RNA synthesis. However, heterogeneity among tumour cells and SGLT-2 inhibitor drugs limit the generalizability of pre-clinical studies.

METHODS

This is a narrative review discussing the potential anti-cancer effects of SGLT-2 inhibitors, an oral glucose-lowering medication used in patients with type II diabetes mellitus. This review discusses underlying mechanisms, pre-clinical and clinical trial data, epidemiological data and future perspectives on the use of SGLT-2 inhibitors in cancer treatment.

RESULTS

Type II diabetes is linked to various comorbidities and malignancies, but some glucose-slowering medications may have a preventive role in cancer. The use of SGLT-2 inhibitors was associated with bladder cancer based on mice studies. However, meta-analyses showed no significant increase in overall malignancy incidence of any specific type, except for empagliflozin and bladder cancer association. SGLT-2 inhibitors can potentially reduce the heart damage caused by doxorubicin and sunitinib, while enhancing the anti-cancer effects of doxorubicin. Combining SGLT-2 inhibitors with doxorubicin may allow higher doses of chemotherapy use. Multiple ongoing clinical trials are investigating the potential therapeutic potential of SGLT-2 inhibitors in various types of cancer.

CONCLUSION

More large-scale pre-clinical and clinical studies are needed to explore their potential preventive and therapeutic roles of SGLT-2 inhibitors in cancer treatment. In this narrative review, our aim is to explore the pre-clinical and clinical data regarding the potential anti-cancer effects of SGLT-2 inhibitors including the hypothetical pathophysiological mechanisms.

Potential Underlying Mechanisms Explaining the Cardiorenal Benefits of Sodium-Glucose Cotransporter 2 Inhibitors

There is a bidirectional pathophysiological interaction between the heart and the kidneys, and prolonged physiological stress to the heart and/or the kidneys can cause adverse cardiorenal complications, including but not limited to subclinical cardiomyopathy, heart failure and chronic kidney disease. Whilst more common in individuals with Type 2 diabetes, cardiorenal complications also occur in the absence of diabetes. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) were initially approved to reduce hyperglycaemia in patients with Type 2 diabetes. Recently, these agents have been shown to significantly improve cardiovascular and renal outcomes in patients with and without Type 2 diabetes, demonstrating a robust reduction in hospitalisation for heart failure and reduced risk of progression of chronic kidney disease, thus gaining approval for use in treatment of heart failure and chronic kidney disease. Numerous potential mechanisms have been proposed to explain the cardiorenal effects of SGLT2i. This review provides a simplified summary of key potential cardiac and renal mechanisms underlying the cardiorenal benefits of SGT2i and explains these mechanisms in the clinical context. Key mechanisms related to the clinical effects of SGLT2i on the heart and kidneys explained in this publication include their impact on (1) tissue oxygen delivery, hypoxia and resultant ischaemic injury, (2) vascular health and function, (3) substrate utilisation and metabolic health and (4) cardiac remodelling. Knowing the mechanisms responsible for SGLT2i-imparted cardiorenal benefits in the clinical outcomes will help healthcare practitioners to identify more patients that can benefit from the use of SGLT2i.

A novel risk factor for malignancy: Albuminuria

Cancer is the second leading cause of death among the adult population following cardiovascular diseases. Prevention and earlier diagnosis are among the cornerstones in the management of malignancies. Albuminuria is a diagnostic criterion for chronic kidney disease and has been associated with multiple conditions including cardiovascular diseases and systemic inflammation while the association between albuminuria and malignancy has been inadequately addressed. Large-scale observational studies with long follow-up periods demonstrate a statistically significant association between albuminuria and overall malignancy incidence, especially urothelial malignancy incidence. However, the underlying pathophysiology linking these two entities is not a straightforward causal relationship but most likely a multidirectional relationship including a causal link. In this narrative review, we evaluate the clinical studies investigating the association between albuminuria and malignancy along with potential underlying mechanisms linking them. We also summarize data on the impact of treatment modalities prescribed for albuminuria and/or proteinuria on the prevention or prognosis of malignancies.

Nephrotic Syndrome for the Internist

Nephrotic syndrome (NS) is a key clinical entity for the internist to recognize and understand. A wide range of infectious, metabolic, malignant, and autoimmune processes drive nephrosis, leading to a syndrome defined by proteinuria, edema, and hypoalbuminemia. NS occurs due to increased permeability to proteins at the level of the glomerulus, which allows for passage of albumin and other proteins into the urine. Proteinuria leads to a cascade of clinical complications characterized by fluid accumulation, kidney inflammation, and dysregulation of coagulation and immunity. In this article, the authors review the clinically important etiologies of NS that should inform an initial clinical evaluation.

Canagliflozin on top of dual renin-angiotensin system blockade in a woman with partial acquired lipodystrophy, type 2 diabetes and severely proteinuric chronic kidney disease: a case report

Sodium glucose cotransporter 2 inhibitors have proven strong efficacy in reducing end-stage renal disease in patients with type 2 diabetes. We are presenting here the case of a 40-year-old woman with acquired partial lipodystrophy, type 2 diabetes and essential hypertension complicated by chronic kidney disease and proteinuria in the nephrotic range. She first came to our attention in 2012; estimated glomerular filtration rate (eGFR) was 41.5 ml/min/1.73 m² and total proteinuria was 375 mg/24h; she was treated with dual renin angiotensin system blocking. Proteinuria significantly increased during the following years, reaching a nephrotic range (>5 g/day). A kidney biopsy revealed a tubule-interstitial involvement compatible with type 2 diabetes. Leptin replacement therapy, started in 2018, improved glycaemic control and lipid profile, also determining a reduction in insulin total daily dose. In 2019, after the publication of the CREDENCE study, canagliflozin was started on top of losartan and ramipril. After an initial, expected eGFR drop, kidney function stabilized, and albuminuria significantly reduced (from 4120 to 984 mg/24h), while serum potassium showed only minimal increase. At last follow-up (2022) total proteinuria was still reducing (510 mg/24h), while kidney function was substantially unchanged (eGFR 40 ml/min/1.73 m²). This case report suggests that, despite not recommended in international guidelines, the use of SGLT2i in combination with dual renin angiotensin system blockade should be considered in specific conditions and under close clinical monitoring.