New Glucose-Lowering Agents for Diabetic Kidney Disease

Practical guide: Glucagon-like peptide-1 and dual glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonists in diabetes mellitus

In 2005, exenatide became the first approved glucagon-like peptide-1 receptor agonist (GLP-1 RA) for type 2 diabetes mellitus (T2DM). Since then, numerous GLP-1 RAs have been approved, including tirzepatide, a novel dual glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 RA, which was approved in 2022. This class of drugs is considered safe with no hypoglycemia risk, making it a common second-line choice after metformin for treating T2DM. Various considerations can make selecting and switching between different GLP-1 RAs challenging. Our study aims to provide a comprehensive guide for the usage of GLP-1 RAs and dual GIP and GLP-1 RAs for the management of T2DM.

SGLT-2 inhibitors and prevention of contrast-induced nephropathy in patients with diabetes undergoing coronary angiography and percutaneous coronary interventions: systematic review and meta-analysis

Introduction

SGLT2 inhibitors (SGLT2Is) have demonstrated cardioprotective and nephroprotective effects in patients with and without diabetes. Recent studies suggest that SGLT2Is may reduce the risk of contrast-induced nephropathy (CIN) in patients with diabetes undergoing coronary arteriography (CAG) or percutaneous coronary interventions (PCI). However, the evidence is still inconclusive. We aimed to systematically review the evidence regarding the potential nephroprotective role of SGLT2Is in preventing CIN in this population.

Methods

We searched for studies in six databases published up to September 30, 2023, following a PECO/PICO strategy. Initially, we meta-analyzed five studies, but due to several reasons, mainly methodological concerns, we excluded one RCT. In our final meta-analysis, we included four observational studies.

Results

This meta-analysis comprised 2,572 patients with diabetes undergoing CAG or PCI, 512 patients treated with SGLT2Is, and 289 events of CIN. This is the first meta-analysis demonstrating that SGLT2Is may reduce the risk of developing CIN by up to 63% (RR 0.37; 95% CI 0.24-0.58) in patients with diabetes undergoing CAG or PCI, compared to not using SGLT2Is. Statistical heterogeneity was not significant (I2 = 0%, p = 0.91). We assessed the certainty of the evidence of this systematic review and meta-analysis, according to the GRADE criteria, as moderate.

Conclusion

SGLT2Is significantly reduce the risk of CIN by up to 63% in patients with diabetes undergoing CAG or PCI. Clinical trials are needed; several are already underway, which could confirm our findings and investigate other unresolved issues, such as the optimal dose, type, and duration of SGLT2 inhibitor therapy to prevent CIN.

Systematic Review

PROSPERO, identifier CRD42023412892.

Mitochondrially targeted tamoxifen alleviates markers of obesity and type 2 diabetes mellitus in mice

Type 2 diabetes mellitus represents a major health problem with increasing prevalence worldwide. Limited efficacy of current therapies has prompted a search for novel therapeutic options. Here we show that treatment of pre-diabetic mice with mitochondrially targeted tamoxifen, a potential anti-cancer agent with senolytic activity, improves glucose tolerance and reduces body weight with most pronounced reduction of visceral adipose tissue due to reduced food intake, suppressed adipogenesis and elimination of senescent cells. Glucose-lowering effect of mitochondrially targeted tamoxifen is linked to improvement of type 2 diabetes mellitus-related hormones profile and is accompanied by reduced lipid accumulation in liver. Lower senescent cell burden in various tissues, as well as its inhibitory effect on pre-adipocyte differentiation, results in lower level of circulating inflammatory mediators that typically enhance metabolic dysfunction. Targeting senescence with mitochodrially targeted tamoxifen thus represents an approach to the treatment of type 2 diabetes mellitus and its related comorbidities, promising a complex impact on senescence-related pathologies in aging population of patients with type 2 diabetes mellitus with potential translation into the clinic.

Senescent cells play a role in pathogenesis of diabetes, and senolytic agents can improve obesity- and diabetes-related pathologies. Here the authors report that mitochondrially targeted tamoxifen, a potential anti-cancer agent with senolytic activity, alleviates symptoms of obesity and prediabetes in mice, potentially via reduction of food intake and elimination of senescent cells.

Effect of metformin on microvascular outcomes in patients with type 2 diabetes: A systematic review and meta-analysis

AIMS

Examine the efficacy of metformin compared to placebo or other glucose-lowering medications on microvascular outcomes in patients with Type 2 Diabetes Mellitus (T2DM).

METHODS

MEDLINE, EMBASE, Web of Science, and Scopus were searched from database inception to March 2020. We included randomized clinical trials of patients with T2DM receiving metformin compared with another active glucose-lowering treatment or placebo in which a microvascular outcome was assessed. The risk of bias was assessed using the Cochrane Risk of Bias tool. Microvascular complications included kidney-related outcomes, retinopathy, and peripheral neuropathy. An inverse-weighted variance random-effect meta-analysis was performed to estimate drugs effect over microvascular disease. PROSPERO (CRD42019120365).

RESULTS

Nineteen RCTs (n = 18,181) were included. Metformin increased estimated glomerular filtration rate (eGFR) by a mean difference (MD) of 1.08 (95% CI 0.84 to 1.33 ml/min/1.73 m²) after 24 weeks. No effect was found on urinary albumin-creatinine ratio, serum creatinine, and end-stage kidney disease; Patient-important outcomes regarding kidney disease, retinal outcomes, peripheral neuropathy or quality of life were not assessed by any of the included studies and could not be analyzed.

CONCLUSIONS

There is no evidence of clinically significant beneficial effect of metformin therapy as compared to other glucose-lowering medications or placebo on the examined microvascular complications.

MicroRNAs and their delivery in diabetic fibrosis

The global prevalence of diabetes mellitus was estimated to be 463 million people in 2019 and is predicted to rise to 700 million by 2045. The associated financial and societal costs of this burgeoning epidemic demand an understanding of the pathology of this disease, and its complications, that will inform treatment to enable improved patient outcomes. Nearly two decades after the sequencing of the human genome, the significance of noncoding RNA expression is still being assessed. The family of functional noncoding RNAs known as microRNAs regulates the expression of most genes encoded by the human genome. Altered microRNA expression profiles have been observed both in diabetes and in diabetic complications. These transcripts therefore have significant potential and novelty as targets for therapy, therapeutic agents and biomarkers.

Renal Benefits of SGLT 2 Inhibitors and GLP-1 Receptor Agonists: Evidence Supporting a Paradigm Shift in the Medical Management of Type 2 Diabetes

Diabetic nephropathy (DN) is one of the most perilous side effects of diabetes mellitus type 1 and type 2 (T1DM and T2DM).). It is known that sodium/glucose cotransporter 2 inhibitors (SGLT 2i) and glucagone like peptide-1 receptor agonists (GLP-1 RAs) have renoprotective effects, but the molecular mechanisms are still unknown. In clinical trials GLP-1 analogs exerted important impact on renal composite outcomes, primarily on macroalbuminuria, possibly through suppression of inflammation-related pathways, however enhancement of natriuresis and diuresis is also one of possible mechanisms of nephroprotection. Dapagliflozin, canagliflozin, and empagliflozin are SGLT2i drugs, useful in reducing hyperglycemia and in their potential renoprotective mechanisms, which include blood pressure control, body weight loss, intraglomerular pressure reduction, and a decrease in urinary proximal tubular injury biomarkers. In this review we have discussed the potential synergistic and/or additive effects of GLP 1 RA and SGLT2 inhibitors on the primary onset and progression of kidney disease, and the potential implications on current guidelines of diabetes type 2 management.

Trends in medication utilization, glycemic control and outcomes among type 2 diabetes patients in a tertiary referral center in Singapore from 2007 to 2017

BACKGROUND

Use of glucose-lowering agents is a cornerstone in combating type 2 diabetes (T2DM). Treatment guidelines have changed significantly over the past decade. We report temporal trends in medication utilization, glycemic control and rate of severe hypoglycemia in T2DM patients at a tertiary referral center in Singapore.

METHODS

We analyzed data of 36 924 T2DM patients seen at Singapore General Hospital from 2007 to 2017. Annual age-, sex- and racially-standardized proportions of patients (a) prescribed with each class of glucose-lowering agent, (b) on various glucose-lowering regimens, and (c) had an HbA_1c of less than 6%, 6% to less than 7%, 7% to less than 8%, 8% to less than 9%, or 9% or more were estimated using logistic regression. Poisson regression was used to estimate standardized rate of severe hypoglycemia.

RESULTS

From 2007 to 2017, use of metformin (45.9% to 59.6%) and insulin (24.4% to 57.9%) increased, while utilization of sulfonylureas (52.0% to 44.9%) decreased (all P < 0.001). Utilization of dipeptidyl peptidase-4 inhibitors (1.2% to 31.2%) and sodium-glucose cotransporter-2 inhibitors (0.5% to 7.4%) increased from 2008 to 2017 and 2012 to 2017, respectively (all P < 0.001). More patients were prescribed a combination of insulin and oral agents (17.3% to 46.0%, P < 0.001). The proportion of patients with HbA_1c of 8% or more increased (33.7% to 36.0%, P < 0.001). Rates of severe hypoglycemia (5.0 to 8.4 per 100 patient-years, P < 0.001) also rose.

CONCLUSION

Medication utilization patterns have changed significantly over the past 11 years with a shift towards newer agents. Glycemic control has remained stable, and rate of severe hypoglycemia increased. Further analysis is required before causal relationships can be inferred.

Pharmacological Management of Diabetic Nephropathy

INTRODUCTION

Diabetes mellitus (DM) is one of the most common diseases worldwide. Its adverse effects on several body organs, have made treatment of DM a priority. One of the most serious complications of DM is diabetic nephropathy (DN).

OBJECTIVE

The aim of this review is to critically discuss available data on the pharmacological management of DN.

METHODS

A comprehensive review of the literature was performed to identify studies assessing the impact of several drug classes on DN.

RESULTS

Several studies have been conducted in order to find a novel and effective treatment of DN. So far, the cornerstone therapy of DN consists of renin-angiotensin system (RAS) inhibitors, agents that decrease the synthesis of intrarenal angiotensin II or block its receptors. Their antiproteinuric and antihypertensive effects can not only decelerate the progress of DN but prevent its onset as well. Novel antidiabetic drugs, such as sodium-glucose cotransporter 2 inhibitors (SGLT-2i) and glucagon-like peptide- 1 receptor agonists (GLP-1 RA), are promising agents in the therapy of DN, due to their positive effect on renal and cardiovascular adverse events. From lipid-lowering agents, atorvastatin improves DN up to stage 3 and substantially reduces CVD.

CONCLUSION

RAS inhibitors, SGLT-2i and GLP-1 agonists were found to be beneficial for the treatment of DN. Larger renal trials are needed in order to incorporate these drugs into the first line treatment of DN.

The SGLT2 Inhibitor Empagliflozin Might Be a New Approach for the Prevention of Acute Kidney Injury

Three randomized control trials (Canagliflozin Cardiovascular Assessment Study, Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients [EMPA-REG OUTCOME], and Dapagliflozin Effect on Cardiovascular Events-Thrombolysis in Myocardial Infarction 58 [DECLARE-TIMI 58]) showed that the sodium-glucose co-transporter 2 (SGLT2) inhibitors, originally developed as glucose-lowering drugs, are associated with a lower rate of adverse renal outcomes, such as need for renal replacement therapy, doubling of serum creatinine, and loss of glomerular filtration rate (GFR) compared to those in placebo groups. Besides, canagliflozin and empagliflozin also showed a lower risk of progression to macroalbuminuria. The EMPA-REG OUTCOME trial and DECLARE-TIMI 58 trial also indicated that these SGLT2 inhibitors might have beneficial effects on the prevention of acute kidney injury. The United States Food and Drug Administration (FDA) warned of the risk of acute kidney injury for canagliflozin and dapagliflozin. We compared canagliflozin, empagliflozin, and dapagliflozin with respect to chemical structure and pharmacological properties, to explain the observed differences in preventing acute kidney injury, and put forward the hypotheses of the potential mechanisms of different effects of SGLT2 inhibitors on acute kidney injury. Given the raising clinical use of SGLT2 inhibitors, our review should stimulate further basic science and clinical studies in order to definitively understand the role of SGLT2 inhibitors in acute kidney injury. A weakness of the clinical data obtained so far is the fact that the statements concerning acute kidney injury are just based on safety data - mainly creatine measurements. However, given the mode of action of SGLT2 blockers, initiation of a therapy with a SGLT2 blocker will cause an increase of creatine because of its effects on the tubuloglomerular feedback mechanisms/glomerular hemodynamics like RAAS blocking agents do. To really understand the potential effects of SGLT2 inhibitors, we need preclinical and clinical SGLT2 inhibitor studies focusing on all aspects of acute kidney injury - not just changes in GFR biomarkers.

Antihyperglycemic agents as novel natriuretic therapies in diabetic kidney disease

While sodium-glucose cotransporter-2 (SGLT2) inhibitors have been used for the routine management of type 2 diabetes for several years, it is perhaps their natriuretic effects that are most important clinically. This natriuresis activates tubuloglomerular feedback, resulting in reduced glomerular hypertension and proteinuria, leading to renal protective effects in the EMPA-REG OUTCOME and CANVAS Program trials. In the cardiovascular system, it is likely that plasma volume contraction due to natriuresis in response to SGLT2 inhibition is at least in part responsible for the reduction in the risk of heart failure observed in these trials. We compare this mechanism of action with other antidiabetics. Importantly, other diuretic classes, including thiazide and loop diuretics, have not resulted in such robust clinical benefits in patients with type 2 diabetes, possibly because these older agents do not influence intraglomerular pressure directly. In contrast, SGLT2 inhibitors do have important physiological similarities with carbonic anhydrase inhibitors, which also act proximally, and have been shown to activate tubuloglomerular feedback.