SGLT2 inhibition, high-density lipoprotein, and kidney function: a mendelian randomization study.

BACKGROUND: Sodium-glucose cotransporter 2 (SGLT2) inhibition is recognized for its evident renoprotective benefits in diabetic renal disease. Recent data suggest that SGLT2 inhibition also slows down kidney disease progression and reduces the risk of acute kidney injury, regardless of whether the patient has diabetes or not, but the mechanism behind these observed effects remains elusive. The objective of this study is to utilize a mendelian randomization (MR) methodology to comprehensively examine the influence of metabolites in circulation regarding the impact of SGLT2 inhibition on kidney function. METHODS: We used a MR study to obtain associations between genetic proxies for SGLT2 inhibition and kidney function. We retrieved the most recent and comprehensive summary statistics from genome-wide association studies (GWAS) that have been previously published and involved kidney function parameters such as estimated glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio (UACR), and albuminuria. Additionally, we included blood metabolite data from 249 biomarkers in the UK Biobank for a more comprehensive analysis. We performed MR analyses to explore the causal relationships between SGLT2 inhibition and kidney function and two-step MR to discover potential mediating metabolites. RESULTS: The study found that a decrease in HbA1c levels by one standard deviation, which is genetically expected to result in SGLT2 inhibition, was linked to a decreased likelihood of developing type 2 diabetes mellitus (T2DM) (odds ratio [OR] = 0.55 [95% CI 0.35, 0.85], P = 0.007). Meanwhile, SGLT2 inhibition also protects eGFR (ß = 0.05 [95% CI 0.03, 0.08], P = 2.45 × 10- 5) and decreased UACR (-0.18 [95% CI -0.33, -0.02], P = 0.025) and albuminuria (-1.07 [95% CI -1.58, -0.57], P = 3.60 × 10- 5). Furthermore, the study found that of the 249 metabolites present in the blood, only one metabolite, specifically the concentration of small high-density lipoprotein (HDL) particles, was significantly correlated with both SGLT2 inhibition and kidney function. This metabolite was found to play a crucial role in mediating the improvement of renal function through the use of SGLT2 inhibition (ß = 0.01 [95% CI 0.005, 0.018], P = 0.001), with a mediated proportion of 13.33% (95% CI [5.71%, 26.67%], P = 0.020). CONCLUSIONS: The findings of this investigation provide evidence in favor of a genetically anticipated biological linkage between the inhibition of SGLT2, the presence of circulating metabolites, and renal function. The findings demonstrate that the protective effect of SGLT2 inhibition on renal function is mostly mediated by HDL particle concentrations in circulating metabolites. These results offer significant theoretical support for both the preservation of renal function and a better comprehension of the mechanisms underlying SGLT2 inhibition.

Dapagliflozin Does Not Protect against Adriamycin-Induced Kidney Injury in Mice.

INTRODUCTION: Sodium-glucose cotransporter 2 (SGLT2) inhibitors target SGLT2 in renal proximal tubules and promote glycosuria in type 2 diabetes mellitus in humans and animal models, resulting in reduced blood glucose levels. Although clinical trials have shown that SGLT2 inhibitors attenuate the progression of chronic kidney disease, there have been concerns regarding SGLT2-induced acute kidney injury. In this study, we investigated the effect of SGLT2 inhibitors on adriamycin-induced kidney injury in mice. METHODS: Seven-week-old balb/c mice were injected with adriamycin 11.5 mg/kg via the tail vein. Additionally, dapagliflozin was administered via gavage for 2 weeks. The mice were divided into five groups: vehicle, dapagliflozin 3 mg/kg, adriamycin, adriamycin plus dapagliflozin 1 mg/kg, and adriamycin plus dapagliflozin 3 mg/kg. RESULTS: Adriamycin injection reduced the body weight and food and water intakes. Dapagliflozin also decreased the body weight and food and water intakes. Fasting blood glucose and urine volume were not altered by either adriamycin or dapagliflozin. Once adriamycin-induced kidney injury had developed, there were no differences in systolic blood pressure among the groups. Dapagliflozin did not alleviate proteinuria in adriamycin-induced kidney injury. Adriamycin induced significant glomerular and interstitial injury, but dapagliflozin did not attenuate these changes in renal injury. Interestingly, SGLT2 expressions were different between the cortex and medulla of kidneys by dapagliflozin treatment. Dapagliflozin increased SGLT2 expression in medulla, not in cortex. CONCLUSION: Dapagliflozin had no effect on proteinuria or inflammatory changes such as glomerular and tubular damages in adriamycin-induced kidney injury. Our study suggests that dapagliflozin does not protect against adriamycin-induced kidney injury. More experimental studies regarding the effects of SGLT2 inhibitors on various kidney diseases are needed to clarify the underlying mechanisms.

Inhibition of Sodium-Glucose Cotransporter-2 during Serum Deprivation Increases Hepatic Gluconeogenesis via the AMPK/AKT/FOXO Signaling Pathway.

BACKGRUOUND: Sodium-dependent glucose cotransporter 2 (SGLT2) mediates glucose reabsorption in the renal proximal tubules, and SGLT2 inhibitors are used as therapeutic agents for treating type 2 diabetes mellitus. This study aimed to elucidate the effects and mechanisms of SGLT2 inhibition on hepatic glucose metabolism in both serum deprivation and serum supplementation states. METHODS: Huh7 cells were treated with the SGLT2 inhibitors empagliflozin and dapagliflozin to examine the effect of SGLT2 on hepatic glucose uptake. To examine the modulation of glucose metabolism by SGLT2 inhibition under serum deprivation and serum supplementation conditions, HepG2 cells were transfected with SGLT2 small interfering RNA (siRNA), cultured in serum-free Dulbecco's modified Eagle's medium for 16 hours, and then cultured in media supplemented with or without 10% fetal bovine serum for 8 hours. RESULTS: SGLT2 inhibitors dose-dependently decreased hepatic glucose uptake. Serum deprivation increased the expression levels of the gluconeogenesis genes peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α), glucose 6-phosphatase (G6pase), and phosphoenolpyruvate carboxykinase (PEPCK), and their expression levels during serum deprivation were further increased in cells transfected with SGLT2 siRNA. SGLT2 inhibition by siRNA during serum deprivation induces nuclear localization of the transcription factor forkhead box class O 1 (FOXO1), decreases nuclear phosphorylated-AKT (p-AKT), and p-FOXO1 protein expression, and increases phosphorylated-adenosine monophosphate-activated protein kinase (p-AMPK) protein expression. However, treatment with the AMPK inhibitor, compound C, reversed the reduction in the protein expression levels of nuclear p- AKT and p-FOXO1 and decreased the protein expression levels of p-AMPK and PEPCK in cells transfected with SGLT2 siRNA during serum deprivation. CONCLUSION: These data show that SGLT2 mediates glucose uptake in hepatocytes and that SGLT2 inhibition during serum deprivation increases gluconeogenesis via the AMPK/AKT/FOXO1 signaling pathway.

COVID-19 promotes endothelial dysfunction and thrombogenicity: role of proinflammatory cytokines/SGLT2 prooxidant pathway.

BACKGROUND: COVID-19 is associated with an increased risk of cardiovascular complications. Although cytokines have a predominant role in endothelium damage, the precise molecular mechanisms are far from being elucidated. OBJECTIVES: The present study hypothesized that inflammation in patients with COVID-19 contributes to endothelial dysfunction through redox-sensitive SGLT2 overexpression and investigated the protective effect of SGLT2 inhibition by empagliflozin. METHODS: Human plasma samples were collected from patients with acute, subacute, and long COVID-19 (n = 100), patients with non-COVID-19 and cardiovascular risk factors (n = 50), and healthy volunteers (n = 25). Porcine coronary artery endothelial cells (ECs) were incubated with plasma (10%). Protein expression levels were determined using Western blot analyses and immunofluorescence staining, mRNA expression by quantitative reverse transcription-polymerase chain reaction, and the level of oxidative stress by dihydroethidium staining. Platelet adhesion, aggregation, and thrombin generation were determined. RESULTS: Increased plasma levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, monocyte chemoattractant protein-1, and soluble intercellular adhesion molecule-1 were observed in patients with COVID-19. Exposure of ECs to COVID-19 plasma with high cytokines levels induced redox-sensitive upregulation of SGLT2 expression via proinflammatory cytokines IL-1ß, IL-6, and tumor necrosis factor-α which, in turn, fueled endothelial dysfunction, senescence, NF-κB activation, inflammation, platelet adhesion and aggregation, von Willebrand factor secretion, and thrombin generation. The stimulatory effect of COVID-19 plasma was blunted by neutralizing antibodies against proinflammatory cytokines and empagliflozin. CONCLUSION: In patients with COVID-19, proinflammatory cytokines induced a redox-sensitive upregulation of SGLT2 expression in ECs, which in turn promoted endothelial injury, senescence, platelet adhesion, aggregation, and thrombin generation. SGLT2 inhibition with empagliflozin appeared as an attractive strategy to restore vascular homeostasis in COVID-19.

Dapagliflozin Ameliorates Ovulation Disorders via Attenuating Activated Microglia-Mediated Hypothalamic Inflammation in HFD-Fed Mice.

INTRODUCTION: Sodium-glucose cotransporter 2 inhibitors (SGLT2is) have shown neuroprotective effects in obese mice. However, whether SGLT2i can ameliorate high-fat diet (HFD)-related ovulation disorders remains unknown. The aim of this research was to investigate whether dapagliflozin improves HFD-induced ovulatory dysfunction by attenuating microglia-mediated hypothalamic inflammation. METHODS: C57BL/6J female mice fed HFD were treated with dapagliflozin (1 mg/kg) for 22 weeks. Plasma insulin, leptin, luteinizing hormone (LH), estradiol (E2), and IL-1ß levels were also tested. Microglial morphology, cell numbers, and SGLT2 expression were evaluated using immunofluorescence. The expression of IL-1ß, NLRP3, kisspeptin, gonadotropin-releasing hormone (GnRH), SGLT2, insulin, and leptin receptors in the hypothalamus was determined using immunohistochemical staining. We also examined the effects of dapagliflozin on glucose metabolism and the release of inflammatory factor in palmitic acid (PA)-treated HMC3 cells. RESULTS: As expected, dapagliflozin improved HFD-induced metabolic disturbances, peripheral versus central insulin and leptin resistance and also restored the regular estrous cycle. Furthermore, dapagliflozin blunted microglia activation, NLRP3 inflammasome priming, hypothalamic inflammation, and increased the expression of GnRH and kisspeptin at proestrus in the hypothalamus. Additionally, dapagliflozin markedly reduced IL-6 and NO release and fat accumulation, decreased lactic acid production and glucose consumption, and inhibited mammalian target of rapamycin (mTOR) and hexokinase 2 (HK2) expression in PA-treated HMC3 cells. These effects suggest that dapagliflozin reduced the mTOR/HK2-mediated aerobic glycolysis. CONCLUSIONS: Dapagliflozin improved HFD-related ovulation disorders by regulating glucose metabolism through mTOR/HK2 signaling and attenuating microglia-mediated hypothalamic inflammation. These results validate the novel role for the neuroprotection of SGLT2i in HFD-induced obesity and ovulation disorders.

Maternal dexamethasone exposure does not affect glucose tolerance but alters renal haemodynamics in F1 rats in a sex-dependent manner.

INTRODUCTION: Prenatal programming with dexamethasone increases the risk of the development of hyperglycaemia and insulin resistance, leading to diabetes in adulthood. Dexamethasone also causes a decline in renal glomerular filtration in the adult offspring. Sodium-glucose cotransporter-2 (SGLT2) plays a significant role in regulating blood glucose and renal haemodynamics in diabetic patients. However, the role of SGLT2 in dexamethasone-induced programming and the putative sex-dependent effects on the changes named earlier is unknown. Therefore, this study aimed to investigate the impact of maternal dexamethasone treatment on glucose tolerance, insulin sensitivity, renal perfusion and renal function in adult male and female offspring and the possible contribution of SGLT2 to these changes. METHODS AND RESULTS: Pregnant Sprague Dawley rats (F0 ) were treated with either vehicle or dexamethasone (0.2 mg/kg ip) from gestation Day 15 to 20. F1 males and F1 females were randomly selected from each mother at 4 months of age. There was no change in serum Na+ , Na+ excretion rate, glucose tolerance or insulin sensitivity in F1 male or female rats. However, dexamethasone caused significant glomerular hypertrophy and decreases in CSinistrin and CPAH indicating decreased glomerular filtration rate and renal plasma flow, respectively, in dexamethasone-treated F1 male but not female rats. Dexamethasone did not affect SGLT2 mRNA or protein expression in F1 males or females. CONCLUSION: We conclude that dexamethasone-mediated prenatal programming of glomerular volume, renal function and haemodynamics is sex-dependent, occurring only in adult male offspring.

Role of hypoxia inducible factor/vascular endothelial growth factor/endothelial nitric oxide synthase signaling pathway in mediating the cardioprotective effect of dapagliflozin in cyclophosphamide-induced cardiotoxicity.

BACKGROUND: Cyclophosphamide (CP) is a commonly used chemotherapeutic and immunosuppressive alkylating agent. However, cardiac adverse effects of CP interfere with its clinical benefit. Cardio-oncology research is currently an important issue and finding effective cardiopreserving agents is a critical need. For the first time, we aimed to detect if dapagliflozin (DAP) could ameliorate CP-induced cardiac injury and investigated the role of hypoxia inducible factor α (HIF1α)/vascular endothelial growth factor (VEGF)/endothelial nitric oxide synthase (eNOS) pathway. METHODS: Forty male Wistar albino rats were included in the current model. Studied groups are: control group; CP-induced cardiotoxicity group; CP group treated with DAP; CP group treated with DAP and administered a nitric oxide synthase inhibitor; nitro-ω-L-arginine (L-NNA) before DAP to explore the role of eNOS. RESULTS: Our data revealed that CP could induce cardiac damage as manifested by significant increases in cardiac enzymes, blood pressure, malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), HIF1α, sodium glucose co-transporter 2 (SGLT2) and cleaved caspase-3 levels with toxic histopathological changes. However, there are significant decreases in reduced glutathione (GSH), total antioxidant capacity (TAC), VEGF, and eNOS. On the opposite side, co-administration of DAP showed marked improvement of CP-induced cardiac damage that may be due to its ability to inhibit SGLT2, antioxidant, anti-inflammatory and anti-apoptotic properties. Results showed decreasing the cardioprotective effect of DAP on administration of L-NNA, reflecting the critical effect of eNOS in mediating such protection. CONCLUSION: DAP could reduce CP cardiotoxicity based upon its ability to modulate SGLT2 and HIF1α/VEGF/eNOS signaling pathway.

Finerenone Added to RAS/SGLT2 Blockade for CKD in Alport Syndrome. Results of a Randomized Controlled Trial with Col4a3-/- Mice.

SIGNIFICANCE STATEMENT: We hypothesized that triple therapy with inhibitors of the renin-angiotensin system (RAS), sodium-glucose transporter (SGLT)-2, and the mineralocorticoid receptor (MR) would be superior to dual RAS/SGLT2 blockade in attenuating CKD progression in Col4a3 -deficient mice, a model of Alport syndrome. Late-onset ramipril monotherapy or dual ramipril/empagliflozin therapy attenuated CKD and prolonged overall survival by 2 weeks. Adding the nonsteroidal MR antagonist finerenone extended survival by 4 weeks. Pathomics and RNA sequencing revealed significant protective effects on the tubulointerstitium when adding finerenone to RAS/SGLT2 inhibition. Thus, triple RAS/SGLT2/MR blockade has synergistic effects and might attenuate CKD progression in patients with Alport syndrome and possibly other progressive chronic kidney disorders. BACKGROUND: Dual inhibition of the renin-angiotensin system (RAS) plus sodium-glucose transporter (SGLT)-2 or the mineralocorticoid receptor (MR) demonstrated additive renoprotective effects in large clinical trials. We hypothesized that triple therapy with RAS/SGLT2/MR inhibitors would be superior to dual RAS/SGLT2 blockade in attenuating CKD progression. METHODS: We performed a preclinical randomized controlled trial (PCTE0000266) in Col4a3 -deficient mice with established Alport nephropathy. Treatment was initiated late (age 6 weeks) in mice with elevated serum creatinine and albuminuria and with glomerulosclerosis, interstitial fibrosis, and tubular atrophy. We block-randomized 40 male and 40 female mice to either nil (vehicle) or late-onset food admixes of ramipril monotherapy (10 mg/kg), ramipril plus empagliflozin (30 mg/kg), or ramipril plus empagliflozin plus finerenone (10 mg/kg). Primary end point was mean survival. RESULTS: Mean survival was 63.7±10.0 days (vehicle), 77.3±5.3 days (ramipril), 80.3±11.0 days (dual), and 103.1±20.3 days (triple). Sex did not affect outcome. Histopathology, pathomics, and RNA sequencing revealed that finerenone mainly suppressed the residual interstitial inflammation and fibrosis despite dual RAS/SGLT2 inhibition. CONCLUSION: Experiments in mice suggest that triple RAS/SGLT2/MR blockade may substantially improve renal outcomes in Alport syndrome and possibly other progressive CKDs because of synergistic effects on the glomerular and tubulointerstitial compartments.

Functional and Clinical Importance of SGLT2-inhibitors in Frailty: From the Kidney to the Heart.

SGLT2 (sodium-glucose cotransporter 2) enables glucose and sodium reabsorption in the kidney. SGLT2-inhibitors (also known as gliflozins, which include canagliflozin, dapagliflozin, empagliflozin, and ertugliflozin) act by increasing glycosuria, thereby reducing glycemia. These drugs are critical to reach and keep glycemic control, a crucial feature, especially in patients with comorbidities, like frail individuals. Several studies evaluated the effects of SGLT2-inhibitors in different settings beyond diabetes, revealing that they are actually pleiotropic drugs. We recently evidenced the favorable effects of SGLT2-inhibition on physical and cognitive impairment in frail older adults with diabetes and hypertension. In the present overview, we summarize the latest clinical and preclinical studies exploring the main effects of SGLT2-inhibitors on kidney and heart, emphasizing their potential beneficial actions in frailty.

Improvement of Global Longitudinal Strain and Myocardial Work in Type 2 Diabetes Patients on Sodium-Glucose Cotransporter 2 Inhibitors Therapy.

ABSTRACT: Sodium-glucose cotransporter 2 inhibitors (SGLT2-i) are a novel class of oral hypoglycemic agents currently used among patients with type 2 diabetes mellitus (T2DM). The effects of SGLT2-i inhibitors on cardiac structure and function are not fully understood. The aim of this study is to evaluate the echocardiographic changing among patients with well-controlled T2DM treated with SGLT2-i in real-world setting. Thirty-five well-controlled T2DM patients (65 ± 9 years, 43.7% male) with preserved left ventricular ejection fraction (LVEF) and 35 age and sex-matched controls were included. T2DM patients underwent clinical and laboratory evaluation; 12-lead surface electrocardiogram; 2-dimensional color Doppler echocardiography at enrolment, before SGLT2-i administration, and at 6 months follow-up after an uninterrupted 10 mg once daily of empagliflozin (n: 21) or dapagliflozin (n: 14). Standard echocardiographic measurements, LV global longitudinal strain (LV-GLS), global wasted work, and global work efficiency were calculated. T2DM patients showed higher E\E' ratio (8.3 ± 2.5 vs. 6.3 ± 0.9; P < 0.0001 ) and lower LV-GLS (15.8 ± 8.1 vs. 22.1 ± 1.4%; P < 0.0001 ) and global myocardial work efficiency (91 ± 4 vs. 94 ± 3%; P: 0.0007 ) compared with age and sex-matched controls. At 6-month follow-up, T2DM patients showed a significant increase in LVEF (58.9 ± 3.2 vs. 62 ± 3.2; P < 0.0001 ), LV-GLS (16.2 ± 2.8 vs. 18.7 ± 2.4%; P = 0.003 ), and global work efficiency (90.3 ± 3.5 vs. 93.3 ± 3.2%; P = 0.0004 ) values; conversely, global wasted work values (161.2 ± 33.6 vs. 112.72 ± 37.3 mm Hg%; P < 0.0001 ) significantly decreased. Well-controlled T2DM patients with preserved LVEF who are treated with a SGLT2-i on top of the guidelines direct medical therapy showed a favorable cardiac remodeling, characterized by the improvement of LV-GLS and myocardial work efficiency.

Effects of SGLT2 inhibitors on the intestinal bacterial flora in Japanese patients with type 2 diabetes mellitus.

Selective inhibitors of sodium glucose co-transporter-2 (SGLT2) suppress renal glucose reabsorption and promote urinary glucose excretion, thereby lowering blood glucose. SGLT2 inhibitors have been reported to reduce body weight. However, the mechanism underlying the reduction in the body weight induced by SGLT2 inhibitor treatment remains to be elucidated. In this study, we investigated the effects of SGLT2 inhibitors on the intestinal bacterial flora. A total of 36 Japanese patients with type 2 diabetes mellitus received a SGLT2 inhibitor (luseogliflozin or dapagliflozin) for 3 months, and the prevalences of balance-regulating bacteria and balance-disturbing bacteria in the feces of the patients before and after SGLT2 inhibitor treatment were determined. SGLT2 inhibitor treatment was associated with a significant increase of the overall prevalence of the 12 types of balance-regulating bacteria. In addition, significant increases in the prevalences of the short-chain fatty acid (SCFAs)-producing bacteria among the balance-regulating bacteria were also observed. Individual analyses of the balance-regulating bacteria revealed that the SGLT2 inhibitor treatment was associated with a significant increase in the prevalence of Ruminococci, which are balance-regulating bacteria classified as SCFAs-producing bacteria. However, SGLT2 inhibitor had no effect on the balance-disturbing bacteria. These results suggested that SGLT2 inhibitor treatment was associated with an overall increase in the prevalence of balance-regulating bacteria. Among the balance-regulating bacteria, the prevalences of SCFAs-producing bacteria increased. SCFAs have been reported to prevent obesity. The results of the present study suggest that SGLT2 inhibitors might induce body weight reduction via their actions on the intestinal bacterial flora.

Dapagliflozin inhibits the activity of lateral habenula to alleviate diabetes mellitus-induced depressive-like behavior.

The prevalence of depression in diabetes mellitus (DM) patients is very high, and it severely impacts the prognosis and quality of life of these patients. Sodium-glucose co-transporter 2 (SGLT2) inhibitors, a new type of oral hypoglycemic drugs, have been shown to alleviate depressive symptoms in DM patients; however, the mechanism underlying this effect is not well understood. The lateral habenula (LHb) plays an important role in the pathogenesis of depression expresses SGLT2, suggesting that the LHb may mediate antidepressant effects of SGLT2 inhibitors. The current study aimed to investigate the involvement of the LHb in the antidepressant effects of the SGLT2 inhibitor dapagliflozin. Chemogenetic methods were used to manipulate the activity of LHb neurons. Behavioral tests, Western blotting, immunohistochemistry, and neurotransmitter assays were used to determine the effects of dapagliflozin on the behavior of DM rats, AMP-activated protein kinase (AMPK) pathway and c-Fos expression in the LHb and 5-hydroxyindoleacetic acid (5-HIAA)/5-hydroxytryptamine (5-HT) ratio in the dorsal raphe nucleus (DRN). We found that DM rats demonstrated depressive-like behavior, increased c-Fos expression, and decreased AMPK pathway activity in the LHb. Inhibition of LHb neurons alleviated the depressive-like behavior of DM rats. Both systemic and local LHb administration of dapagliflozin alleviated the depressive-like behavior and reversed the changes of the AMPK pathway and c-Fos expression in the LHb of DM rats. Dapagliflozin, when microinjected into the LHb, also increased 5-HIAA /5-HT in the DRN. These results suggest that dapagliflozin directly acts on the LHb to alleviate DM-induced depressive-like behavior and that the underlying mechanism involves activating the AMPK signaling pathway, leading to the inhibition of LHb neuronal activity, which in turn increases serotonergic activity in the DRN. These results will help develop new strategies for the treatment of DM-induced depression.

SGLT2 inhibition in heart failure with reduced or preserved ejection fraction: Finding the right patients to treat.

Sodium-glucose transport inhibitors (SGLT2i) are effective in heart failure (HF) with ejection fraction (EF) <40% (referred to as HF with reduced EF - HFrEF) and left ventricular EF (LVEF) >40%. Current evidence suggests that SGLT2i should be initiated across a large spectrum of EFs and renal function in patients with HF and with and without diabetes. We reviewed the benefits of SGLT2i in the entire spectrum of HF and provided some clues that may guide physicians in their strategy of initiating and maintaining SGLT2i (with or without SGLT1i effect) therapy. Taken together, the evidence thus far arises from an array of trials performed in different settings (acute/chronic), risk categories, and phenotypes of HF (HFrEF/HFpEF), and in addition to the most common HF therapies, supports the homogenous effect of SGLT2i across a large spectrum of patients with HF. SGLT2i appear to be effective and well-tolerated drugs in the majority of clinical HF scenarios, regardless of LVEF, estimated glomerular filtration rate, diabetic status or the level of the acuteness of the clinical setting. Therefore, most patients with HF should be treated with SGLT2i. However, in the face of the therapeutic inertia that has been observed in HF over the past decades, the actual implementation of SGLT2i in routine practice remains the most significant challenge.

Direct actions of dapagliflozin and interactions with LCZ696 and spironolactone on cardiac fibroblasts of patients with heart failure and reduced ejection fraction.

AIMS: Inhibitors of SGLT2 (SGLT2i) have shown a positive impact in patients with chronic heart failure and reduced ejection fraction (HFrEF). Nonetheless, the direct effects of SGLT2i on cardiac cells and how their association with main drugs used for HFrEF affect the behaviour and signalling pathways of myocardial fibroblasts are still unknown. We aimed to determine the effects of dapagliflozin alone and in combination with sacubitril/valsartan (LCZ696) or spironolactone on the function of myocardial fibroblasts of patients with heart failure and reduced ejection fraction (HFrEF). METHODS AND RESULTS: Myocardial fibroblasts isolated from HFrEF patients (n = 5) were treated with dapagliflozin alone (1 nM-1 µM) or combined with LCZ696 (100 nM) or spironolactone (100 nM). The migratory rate was determined by wound-healing scratch assay. Expression of heart failure (HF) markers and signalling pathways activation were analysed with multiplexed protein array. Commercially available cardiac fibroblasts from healthy donors were used as Control (n = 4). Fibroblasts from HFrEF show higher migratory rate compared with control (P = 0.0036), and increased expression of HF markers [fold-change (Log2): COL1A1-1.3; IL-1b-1.9; IL-6-1.7; FN1-2.9 (P < 0.05)]. Dapagliflozin slowed the migration rate of HFrEF fibroblasts in a dose-dependent manner and markedly decreased the expression of IL-1ß, IL-6, MMP3, MMP9, GAL3, and FN1. SGLT2i had no effect on control fibroblasts. These effects were associated with decreased phosphorylation of AKT/GSK3 and PYK2 kinases and the signal transducer and activator of transcription (STAT). A combination of dapagliflozin + LCZ696 further decreased fibroblast migration, although it did not have a significant effect on the regulation of signalling pathways and the expression of biomarkers induced by SGLT2 inhibition alone. In contrast, the combination of dapagliflozin + spironolactone did not change the migration rate of fibroblast but significantly altered SGLT2i responses on MMP9, GAL3, and IL-1b expression, in association with increased phosphorylation of the kinases AKT/GSK3 and ERK1/2. CONCLUSIONS: SGLT2i, LCZ696, and spironolactone modulate the function of isolated myocardial fibroblasts from HFrEF patients through the activation of different signalling pathways. The combination of SGLT2i + LCZ696 shows an additive effect on migration, while spironolactone modifies the signalling pathways activated by SGLT2i and its beneficial effects of biomarkers of heart failure.

Renoprotective Effects of SGLT2 Inhibitors.

SGLT2 inhibitors can protect the kidneys of patients with and without type 2 diabetes from failing. This includes blood glucose dependent and independent mechanisms. SGLT2 inhibitors lower glomerular pressure and filtration, thereby reducing the physical stress on the filtration barrier and the oxygen demand for tubular reabsorption. This improves cortical oxygenation, which, together with lesser tubular glucotoxicity and improved mitochondrial function and autophagy, can reduce proinflammatory and profibrotic signaling and preserve tubular function and GFR in long term. By shifting transport downstream, SGLT2 inhibitors may mimic systemic hypoxia and stimulate erythropoiesis, which improves oxygen delivery to the kidney and other organs.

Empagliflozin ameliorates type 2 diabetes mellitus-related diabetic nephropathy via altering the gut microbiota.

BACKGROUND: The dysregulation of gut microbiota can be found in patients with type 2 diabetes mellitus (T2DM)-related diabetic nephropathy (DN). Inhibitors of sodium-glucose co-transporter 2 (SGLT2) were reported to affect gut microbiota. This study aimed to identify whether empagliflozin (EMPA) attenuated DN via regulating gut microbiota. MATERIALS AND METHODS: The high-fat diet (HFD) combining streptozocin (STZ) injection was performed to induce DN in mice. The therapeutic effects of EMPA were observed by staining of renal tissues and urine albumin/creatinine ratio (UACR). Mouse feces were collected for 16S rRNA sequencing. Fecal short-chain fatty acids (SCFAs) and fecal and serum lipopolysaccharide (LPS) were determined. An antibiotic-ablated model was established to confirm the role of the gut microbiota in the actions of EMPA. RESULTS: EMPA reduced the elevation of blood glucose and UACR caused by HFD/STZ. It inhibited the thickening of the colonic crypt and restored goblet cells and the expressions of ZO-1 and Occludin. The 16S rRNA sequencing showed that the diversity of gut microbiota was reduced after HFD/STZ treatment, while it was restored after EMPA treatment. The LPS-producing bacteria, Oscillibacter, and the SCFA-producing bacteria, Bateroid and Odoribacter, were changed after EMPA administration. The therapeutic effects of EMPA on ABX-treated mice were reduced. Meanwhile, the level of fecal SCFAs was decreased, while the levels of fecal and serum LPS were elevated, in T2DM mice, and they were negated by the administration of EMPA. CONCLUSION: EMPA ameliorates T2DM-related DN via altering the gut microbiota, especially reducing LPS-producing bacteria and increasing SCFA-producing bacteria.

Optimal Pharmacologic Treatment of Heart Failure With Preserved and Mildly Reduced Ejection Fraction: A Meta-analysis.

Importance: In recent years, significant progress has been made in the pharmacologic treatment of heart failure (HF) with reduced ejection fraction (HFrEF), but there is still insufficient evidence for drug therapy for HF with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF). Objective: To compare the outcomes associated with different drug combinations for the treatment of HFpEF and HFmrEF. Data Sources: A search of the PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases was conducted for studies published from inception to October 9, 2021. Study Selection: Randomized clinical trials on the use of angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), angiotensin receptor-neprilysin inhibitors (ARNIs), mineralocorticoid receptor antagonists (MRAs), ß-blockers, and sodium-glucose cotransporter 2 (SGLT2) inhibitors for patients with HFpEF or HFmrEF. Data Extraction and Synthesis: Data extraction and bias assessment were independently performed by 2 reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. All data for 3 outcomes were pooled with a fixed-effect model. Main Outcomes and Measures: The main outcomes were first hospitalization for HF, all-cause mortality, and cardiovascular mortality. Hazard ratios (HRs) and 95% credible intervals (CrIs) were evaluated using a bayesian network meta-analysis model. Results: In this analysis, 19 randomized clinical trials, including 20 633 patients with HF and an ejection fraction of 40% or more, without a remarkable risk of bias were included. Compared with placebo, no treatments were associated with a significant reduction in the risk of all-cause death or cardiovascular death. SGLT2 inhibitors, ARNIs, and MRAs were associated with a significant decrease in the risk of HF hospitalization compared with placebo (SGLT2 inhibitors: HR, 0.71 [95% CrI, 0.60-0.83]; ARNIs: HR, 0.76 [95% CrI, 0.61-0.95]; MRAs: HR, 0.83 [95% CrI, 0.69-0.99]), and SGLT2 inhibitors were the optimal drug class in terms of reducing the risk for HF admission. Sensitivity analysis results demonstrated a progressive decrease in the risk of HF admission and an advance in mean rank associated with the increasing use of drug classes. Conclusions and Relevance: The findings of this study suggest that SGLT2 inhibitors were the optimal drug class for HFpEF and HFmrEF, consistent with the most recent guideline recommendation. The incremental use of combinations of SGLT2 inhibitors, ACE inhibitors or ARBs, and ß-blockers may be associated with accumulative benefits in HF hospitalization rather than all-cause death among patients with HFpEF and HFmrEF.

[Hypoglycemia in a patient treated with a SGLT2-inhibitor with HFrEF without diabetes mellitus]. / Hypoglykämie unter SGLT2-Inhibition bei einem Patienten mit HFrEF ohne Diabetes mellitus.

ANAMNESE: HFrEF (heart failure with reduced ejection fraction) with a left ventricular ejection fraction of 25-30 % was detected in a 79-year-old man. For further treatment, inpatient cardiac rehabilitation war carried out. CLINICAL FINDINGS: At the start of the cardiac rehabilitation, patient complained of shortness of breath with little exertion, corresponding to NYHA III. Drug therapy included empagliflozin 10 mg, sacubitril/valsartan 24/26 mg, edoxaban 60 mg, torasemide 5 mg, verapamil 80 mg and amiodarone 200 mg. INVESTIGATIONS: The daily blood sugar profile showed hypoglycemia with values ​​< 3.7 mmol/l (< 67 mg/dl). After consultation with the patient, these occurred with normal food intake and were symptomatic in form of dizziness during the period of hypoglycaemia. DIAGNOSIS: Symptomatic hypoglycaemia on SGLT2(sodium-glucose linked transporter 2)-inhibitor therapy in a patient with HFrEF without diabetes mellitus. THERAPY AND PROGRESS: The therapy with empaglifozin was stopped and a new daily blood sugar profile was carried out, which no longer showed any hypoglycaemic values. CONCLUSION: The presented case raises awareness of the side effect of hypoglycaemia, which occurs very rarely with SGLT2 inhibitors in studies in patients with HFrEF without the presence of diabetes mellitus.

Renoprotective Mechanism of Sodium-Glucose Cotransporter 2 Inhibitors: Focusing on Renal Hemodynamics.

Diabetic kidney disease (DKD) is a prevalent renal complication of diabetes mellitus that ultimately develops into end-stage kidney disease (ESKD) when not managed appropriately. Substantial risk of ESKD remains even with intensive management of hyperglycemia and risk factors of DKD and timely use of renin-angiotensin-aldosterone inhibitors. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce hyperglycemia primarily by inhibiting glucose and sodium reabsorption in the renal proximal tubule. Currently, their effects expand to prevent or delay cardiovascular and renal adverse events, even in those without diabetes. In dedicated renal outcome trials, SGLT2 inhibitors significantly reduced the risk of composite renal adverse events, including the development of ESKD or renal replacement therapy, which led to the positioning of SGLT2 inhibitors as the mainstay of chronic kidney disease management. Multiple mechanisms of action of SGLT2 inhibitors, including hemodynamic, metabolic, and anti-inflammatory effects, have been proposed. Restoration of tubuloglomerular feedback is a plausible explanation for the alteration in renal hemodynamics induced by SGLT2 inhibition and for the associated renal benefit. This review discusses the clinical rationale and mechanism related to the protection SGLT2 inhibitors exert on the kidney, focusing on renal hemodynamic effects.