Diabetes and kidney disease: the role of sodium-glucose cotransporter-2 (SGLT-2) and SGLT-2 inhibitors in modifying disease outcomes

Serum Phosphorus and Hypophosphatemia During Therapy of Diabetic Ketoacidosis in Children: Single-Center, Retrospective Cohort 2016-2022

OBJECTIVES

To assess factors associated with serum phosphorus (P) and hypophosphatemia in children with type 1 diabetes mellitus (T1DM) treated for diabetic ketoacidosis (DKA).

DESIGN

Retrospective cohort.

SETTING

Community-based PICU in a university-affiliated hospital.

PATIENTS

Patients 1-20 years old with T1DM hospitalized for DKA from July 1, 2016, to July 31, 2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We collected age, sex, duration of T1DM, conscious state at presentation, and most recent glycohemoglobin level. P was tested initially and then every 4 hours. Probability of hypophosphatemia and time to hypophosphatemia and hospital length of stay (LOS) were analyzed via binomial and linear mixed-effects regression analyses, respectively. A total of 852 DKA episodes occurred in 365 patients (46.3% female, median age 14.7 yr), of which 158 (18.5%) episodes were new-onset T1DM. Hypophosphatemia developed during 656 of 852 (77%) episodes, including 49 of 852 (5.8%) episodes of severe hypophosphatemia with median (interquartile range) onset 8.0 hours (4.7-11.9 hr) and 12.0 hours (8.1-17.6 hr), respectively, following initiation of therapy. Higher glycohemoglobin was associated with greater odds of hypophosphatemia (odds ratio [OR], 1.22; p < 0.001). However, lower odds of hypophosphatemia were associated with older age (OR, 0.89; p < 0.01), male (OR, 0.11; p = 0.01), longer T1DM duration (OR, 0.87; p < 0.001), and having initial normal conscious state (OR, 0.18; p < 0.01). Older age (3.0%/yr; p = 0.02), T1DM duration (4.1%/yr; p = 0.01), and initial serum P (23.4%/mg/dL; p < 0.001) were associated with later hypophosphatemia. LOS was shorter with increased T1DM duration (3.6%/yr; p < 0.001) and normal conscious state (33.1% shorter; p < 0.001), but longer with increasing glycohemoglobin (4.0%; p < 0.001). All patients survived with normal neurologic function.

CONCLUSIONS

Higher glycohemoglobin was associated with greater odds of hypophosphatemia and longer LOS. Older male, longer duration of T1DM, and conscious at admission were factors associated with lower odds of developing hypophosphatemia and with later onset when it occurred. Hypophosphatemia was associated with longer LOS.

Effect of dapagliflozin on pulmonary vascular remodeling in rats with chronic hypoxic pulmonary arterial hypertension

OBJECTIVE

To investigate the effects of sodium-glucose co-transporter 2 inhibitor dapagliflozin on pulmonary vascular remodeling in a rat model of chronic hypoxic pulmonary arterial hypertension.

METHODS

Eighteen female Sprague-Dawley rats were divided into three groups: control (CON), chronic hypoxia (HYP), and chronic hypoxia + dapagliflozin. The HYP and dapagliflozin groups were subjected to hypoxia and received saline or dapagliflozin. The CON group was normoxic and received saline. Body weight and fasting blood glucose were measured, and after 21 days, lung and heart tissues were analyzed for pulmonary artery reconstruction and right ventricular hypertrophy. Western blotting assessed Bax and Bcl-2 protein levels.

RESULTS

Chronic hypoxia increased pulmonary artery wall thickness and lung fibrosis and caused right ventricular hypertrophy. Dapagliflozin reduced these changes, decreasing artery wall thickness, fibrosis, and hypertrophy while increasing the Bax/Bcl-2 ratio.

CONCLUSION

Dapagliflozin alleviates chronic hypoxia-induced pulmonary artery wall thickening and lung tissue fibrosis in rats, potentially through proapoptotic effects.

Acquired Disorders of Hypomagnesemia

Magnesium disorders are common in clinical practice and when present can manifest clinically as cardiovascular, neuromuscular, or other organ dysfunction. Hypomagnesemia is far more common than hypermagnesemia, which is largely seen in patients with reduced glomerular filtration rates receiving magnesium-containing medications. In addition to inherited disorders of magnesium handling, hypomagnesemia is also seen with excessive gastrointestinal or renal losses and due to medications such as amphotericin B, aminoglycosides, and cisplatin. Laboratory assessment of body magnesium stores largely relies on the measurement of serum magnesium levels that are a poor proxy for total body stores but does correlate with the development of symptoms. Replacement of magnesium can be challenging, with oral replacement strategies being generally more effective at slowly replacing body stores but intravenous replacement being more effective at treating the more life-threatening and severe cases of hypomagnesemia. We conducted a thorough review of the literature using PubMed (1970-2022) and the search terms magnesium, hypomagnesemia, drugs, medications, treatment, and therapy. In the absence of clear data on optimal management of hypomagnesemia, we have made recommendations on magnesium replacement based on our clinical experience.

Drug Therapies Affecting Renal Function: An Overview

Undesirable side effects of medication are inevitable. Due to the role of the kidneys in clearance and filtration, the renal system faces a unique situation when it comes to the side effects of drugs. It has an important role for different classes of drugs to be excreted, and drugs are a key factor for this system to be at risk. Medications in articles were divided into classes using the standard set by the Saudi Pharmaceutical Journal. Many drug classes cause renal insults. The top six classes were pain killers, antibiotics, proton pump inhibitors, antidiabetics, antihyperlipidemics, and agents for erectile dysfunction. Renal insults caused by these agents could vary in severity. Some drugs could cause nephrotoxicity from one dose, while others may only need continuous monitoring. Different populations also operate under different rules, as some people need dose adjustments while others who are medically free of major illnesses do not. A variety of unfavorable outcomes for the kidney could take place, such as acute kidney injury, chronic kidney disease, and end-stage renal disease, and unfortunately, some of these issues could lead to the need for renal replacement therapies. The outcome of this review paper will help multidisciplinary physicians to understand the renal side effects of the most used drug classes in the Kingdom of Saudi Arabia, their destructive mechanisms, and most importantly, the clinical presentations of renal dysfunction in relation to each class. Emphasizing these adverse effects will prevent future unfavorable outcomes, especially in commonly used drugs that are frequently prescribed for different age groups. Moreover, some of these drugs are considered to be over-the-counter medications, which makes them a serious problem that needs to be handled cautiously.

Pre- and Post-Conditioning of the Heart: An Overview of Cardioprotective Signaling Pathways

Since the discovery of ischemic pre- and post-conditioning, more than 30 years ago, the knowledge about the mechanisms and signaling pathways involved in these processes has significantly increased. In clinical practice, on the other hand, such advancement has yet to be seen. This article provides an overview of ischemic pre-, post-, remote, and pharmacological conditioning related to the heart. In addition, we reviewed the cardioprotective signaling pathways and therapeutic agents involved in the above-mentioned processes, aiming to provide a comprehensive evaluation of the advancements in the field. The advancements made over the last decades cannot be ignored and with the exponential growth in techniques and applications. The future of pre- and post-conditioning is promising.

Drug-drug interactions when treating HIV-related metabolic disorders

Introduction: Drug-drug interactions (DDI) between antiretroviral drugs and drugs for the treatment of metabolic disturbances in people living with human immunodeficiency virus (HIV) (PLWH) have represented a problem of paramount importance in the recent times. The problem has been mainly driven by sharing common metabolizing pathways. This problem has classically been worsened by the frequent use of pharmacokinetic boosters to enhance protease inhibitors and some integrase inhibitors plasma levels. Areas covered: This article focuses on the interactions between antiretroviral drugs and those drugs used to treat metabolic disturbances which frequently appear in PLWH. These include dyslipidemia, diabetes mellitus, hyperuricemia, and finally, drugs for the treatment of overweight and clinical obesity. References from PubMed, Embase, or Web of Science, among others, were reviewed. Expert opinion: The advent of safer drugs, in terms of DDI, in the antiretroviral and the metabolic field,such as non-boosted antiretrovirals and drugs with divergent metabolizing paths. Besides, learning by the caregivers on how to decrease and manage DDI, together with the extensive use of online updated DDI databases, has undoubtedly minimized the problem. The foreseeable increase in the burden of HIV-associated comorbidities and their associated treatments anticipates further complexities in the management of DDI in PLWH.

Type 2 diabetes and the kidney: Insights from cardiovascular outcome trials

Diabetic kidney disease (DKD) still remains a progressive condition that is associated with higher risk of end-stage kidney disease and significant cardiovascular morbidity and mortality. Twelve cardiovascular outcome trials in type 2 diabetes (T2D) have been published to date. Most trials with dipeptidyl-peptidase inhibitors (SAVOR-TIMI 53 with saxagliptin, EXAMINE with alogliptin, TECOS with sitagliptin, and CARMELINA with linagliptin) and with glucagon-like peptide-1 receptor agonists (GLP-1RAs) (ELIXA with lixisenatide, LEADER with liraglutide, SUSTAIN-6 with semaglutide, EXCSEL with exenatide once-weekly, and HARMONY with albiglutide) pointed towards reduced albuminuria, which is a surrogate endpoint possibly heralding renal function preservation. The three trials with sodium-glucose co-transporter-2 inhibitors (SGLT-2is) (empagliflozin, canagliflozin and dapagliflozin) also showed a salutary effect on long-term estimated glomerular filtration rate, suggesting that SGLT-2is are more effective at mitigating loss of kidney function than incretin-based therapies; moreover, SGLT-2is also have the advantage of plausible haemodynamic mechanisms for improved renal outcomes. Despite some residual limitations linked to differences in study populations and patient characteristics, the cardiorenal protective actions of SGLT-2is, and to a lesser extent some GLP-1RAs, make them favourable medications for patients with T2D at increased cardiorenal risk. There is room for optimism that their use may change the paradigm of the ineluctable progression of DKD.

Sex differences in diabetes and kidney disease: mechanisms and consequences

Type 1 and type 2 diabetes, along with their accompanying hyperglycemia, are associated with a multitude of comorbidities including the development of diabetic kidney disease. Although the hallmarks of these metabolic disorders have been well characterized in population and animal studies, it is becoming increasingly apparent that diabetes manifests itself differently in men and women. This review summarizes the recent diabetic literature with a focus on known sex differences in clinical and preclinical studies. It explores the physiological differences of glucose handling and the development of diabetes between men and women. This review also uncovers potential mechanisms for these differences, honing in on the vital role that sex hormone signaling plays in the progression of diabetes and renal complications.

Renal and Glucose-Lowering Effects of Empagliflozin and Dapagliflozin in Different Chronic Kidney Disease Stages

Objective: The objective of this study was to investigate the effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors on renal function in different stages of chronic kidney disease (CKD). Design and Methods: We conducted a retrospective cohort study using longitudinal claims data from May 2016-December 2017 from the Chang Gung Research Database. Patients who used one of the three types of SGLT2 inhibitor available at Chang Gung Memorial Hospital, namely empagliflozin 10 mg/tab (Empa10), empagliflozin 25 mg/tab (Empa25), and dapagliflozin 10 mg/tab (Dapa), were included, with the same number of matched non-users. Analysis of variance was used for continuous variables and the chi-square test was applied for categorical variables. Differences in data between two groups were analyzed using an independent t-test, and the basic data before and after treatment were analyzed using generalized estimating equation (GEE). The association among renal function changes was analyzed using a Cox proportional hazards model, with the results presented as unadjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs). Results: Among the 7,624 SGLT2 inhibitor users, 1,696 patients used Empa10, 2,654 used Empa25, and 3,274 used Dapa. Compared with non-users, dapagliflozin had the lowest risk of estimated glomerular filtration rate (eGFR) decrease over 40% from baseline within 1 year (HR 0.36, 95% CI 0.25-0.51). By using the ICD-10-CM code N179, the acute kidney injury (AKI)-related hospitalization rate was lower in Empa10 and Dapa users than in non-users (HR 0.65, 95% CI 0.49-0.86). Conclusion: Lower risk of eGFR decrease over 40% and AKI-related hospitalization was found in all SGLT2 inhibitor users across the different CKD stages.

Preventing and treating kidney disease in patients with type 2 diabetes

INTRODUCTION

Chronic kidney disease (CKD) represents a huge burden in patients with type 2 diabetes (T2DM). This review therefore has the aim of assessing the add-on value of new glucose-lowering agents compared or combined with inhibitors of the renin angiotensin aldosterone system (RAAS) on renal outcomes in T2DM patients.

AREAS COVERED

This article first summarizes the results reported with RAAS inhibitors, mainstay of nephroprotection in T2DM with albuminuria. Second, it describes the positive results with glucagon-like peptide-1 receptor agonists (GLP-1RAs) and, even more impressive, sodium-glucose cotransporter type 2 inhibitors (SGLT2is). Third, besides the potential of combined therapies, it briefly considers some new approaches currently in development.

EXPERT OPINION

RAAS inhibitors exert renoprotective effects beyond their blood pressure lowering effects while SGLT2is, and possibly GLP-1RAs, exert nephroprotection independently of their glucose-lowering activity. These effects were demonstrated not only on surrogate endpoints such as albuminuria and estimated glomerular filtration rate decline, but also on hard endpoints, including progression to end-stage renal disease requiring replacement therapy. The underlying mechanisms are different and potentially complementary on glomerular hemodynamics, arguing for combined therapies. Nevertheless, there is still room for new emerging drugs to tackle CKD in T2DM.

Narrative review of the effects of antidiabetic drugs on albuminuria

Diabetes mellitus is the most prevalent metabolic disorder worldwide. Glycemic control is the main focus of antidiabetic therapy. However, there are data suggesting that some antidiabetic drugs may have intrinsic beneficial renal effects and protect against the development and progression of albuminuria, thus minimizing the risk of diabetic nephropathy. These pharmacological agents can suppress upstream molecular pathways involved in the pathophysiology of diabetes-induced renal dysfunction such as oxidative stress, inflammatory responses, and apoptosis. In this narrative review, the pathophysiology of albuminuria in patients with diabetic nephropathy is discussed. Furthermore, the renoprotective effects of antidiabetic drugs, focusing on albuminuria, are reviewed.

Effects of glucose-lowering agents on surrogate endpoints and hard clinical renal outcomes in patients with type 2 diabetes

Diabetic kidney disease (DKD) represents an enormous burden in patients with type 2 diabetes mellitus (T2DM). Preclinical studies using most glucose-lowering agents have suggested renal-protective effects, but the proposed mechanisms of renoprotection have yet to be defined, and the promising results from experimental studies remain to be translated into human clinical findings to improve the prognosis of patients at risk of DKD. Also, it is important to distinguish effects on surrogate endpoints, such as decreases in albuminuria and estimated glomerular filtration rate (eGFR), and hard clinical endpoints, such as progression to end-stage renal disease (ESRD) and death from renal causes. Data regarding insulin therapy are surprisingly scarce, and it is nearly impossible to separate the effects of better glucose control from those of insulin per se, whereas favourable preclinical data with metformin, thiazolidinediones and dipeptidyl peptidase (DPP)-4 inhibitors are plentiful, and positive effects have been observed in clinical studies, at least for surrogate endpoints. The most favourable renal results have been reported with glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter type-2 inhibitors (SGLT2is). Significant reductions in both albuminuria and eGFR decline have been reported with these classes of glucose-lowering medications compared with placebo and other glucose-lowering agents. Moreover, in large prospective cardiovascular outcome trials using composite renal outcomes as secondary endpoints, both GLP-1RAs and SGLT2is added to standard care reduced renal outcomes combining persistent macro-albuminuria, doubling of serum creatinine, progression to ESRD and kidney-related death; however, to date, only SGLT2is have been clearly shown to reduce such hard clinical outcomes. Yet, as the renoprotective effects of SGLT2is and GLP-1RAs appear to be independent of glucose-lowering activity, the underlying mechanisms are still a matter of debate. For this reason, further studies with renal outcomes as primary endpoints are now awaited in T2DM patients at high risk of DKD, including trials evaluating the potential add-on benefits of combined GLP-1RA-SGLT2i therapies.

Sodium-glucose cotransporter 2 (SGLT-2) inhibitors: a new antidiabetic drug class

Diabetes mellitus is a chronic, complex and multifactorial disease associated characteristically with hyperglycemia. One of the most recently approved antidiabetic drug classes for clinical use are sodium-glucose cotransporter type 2 (SGLT-2) inhibitors. SGLT-2 is a protein expressed in the kidneys, responsible for glucose reabsorption from the glomerular filtrate to the plasma. It is known, nowadays, that diabetic patients show an increased glucose renal reabsorption capacity, caused by the overexpression of the SGLT-2 transporter, thus contributing to hyperglycemia. From establishing this correlation, the SGLT-2 transporter started to be considered as a therapeutic target of interest, culminating in the approval of the first antidiabetic SGLT-2 inhibitor, dapagliflozin (Forxiga® or Farxiga®, Bristol-Myers Squibb & AstraZeneca), in 2012 in Europe. On the other hand, canagliflozin (Invokana®, Janssen Pharmaceutical) was the first drug in this class to be approved by the FDA, the U.S. Food and Drug Administration, in 2013. This review concerns the discovery and development of the first representatives of this class of antidiabetic drugs, and the description of new optimized analogues that are currently in the clinical and preclinical stages of development.

SGLT2 inhibitors-induced electrolyte abnormalities: An analysis of the associated mechanisms

AIMS

Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs that affect serum electrolytes levels. The aim of this review is the detailed presentation of the associated mechanisms of the SGLT2 inhibitors-induced electrolyte abnormalities.

MATERIALS AND METHODS

Eligible trials and relevant articles published in PubMed (last search in July 2017) are included in the review.

RESULTS

SGLT2 inhibitors induce small increases in serum concentrations of magnesium, potassium and phosphate. The small increase in serum phosphate concentration may result in reduced bone density and increased risk of bone fractures, mainly seen with canagliflozin, but recent meta-analyses did not show increased risk of bone fractures with SGLT2 inhibitors.

CONCLUSION

The increases in serum electrolytes levels may play a role in the cardiovascular protection that has been recently reported with empagliflozin and canagliflozin.

SGLT2 Protein Expression Is Increased in Human Diabetic Nephropathy: SGLT2 PROTEIN INHIBITION DECREASES RENAL LIPID ACCUMULATION, INFLAMMATION, AND THE DEVELOPMENT OF NEPHROPATHY IN DIABETIC MICE

There is very limited human renal sodium gradient-dependent glucose transporter protein (SGLT2) mRNA and protein expression data reported in the literature. The first aim of this study was to determine SGLT2 mRNA and protein levels in human and animal models of diabetic nephropathy. We have found that the expression of SGLT2 mRNA and protein is increased in renal biopsies from human subjects with diabetic nephropathy. This is in contrast to db-db mice that had no changes in renal SGLT2 protein expression. Furthermore, the effect of SGLT2 inhibition on renal lipid content and inflammation is not known. The second aim of this study was to determine the potential mechanisms of beneficial effects of SGLT2 inhibition in the progression of diabetic renal disease. We treated db/db mice with a selective SGLT2 inhibitor JNJ 39933673. We found that SGLT2 inhibition caused marked decreases in systolic blood pressure, kidney weight/body weight ratio, urinary albumin, and urinary thiobarbituric acid-reacting substances. SGLT2 inhibition prevented renal lipid accumulation via inhibition of carbohydrate-responsive element-binding protein-β, pyruvate kinase L, SCD-1, and DGAT1, key transcriptional factors and enzymes that mediate fatty acid and triglyceride synthesis. SGLT2 inhibition also prevented inflammation via inhibition of CD68 macrophage accumulation and expression of p65, TLR4, MCP-1, and osteopontin. These effects were associated with reduced mesangial expansion, accumulation of the extracellular matrix proteins fibronectin and type IV collagen, and loss of podocyte markers WT1 and synaptopodin, as determined by immunofluorescence microscopy. In summary, our study showed that SGLT2 inhibition modulates renal lipid metabolism and inflammation and prevents the development of nephropathy in db/db mice.