Renal glucose handling in diabetes and sodium glucose cotransporter 2 inhibition

Determinants of self-reported hypertension among women in South Africa: evidence from the population-based survey

Background

Hypertension (HTN), characterized by an elevation of blood pressure, is a serious public health chronic condition that significantly raises the risks of heart, brain, kidney, and other diseases. In South Africa, the prevalence of HTN (measured objectively) was reported at 46.0% in females, nonetheless little is known regarding the prevalence and risks factors of self-reported HTN among the same population. Therefore, the aim of this study was to examine determinants of self-reported HTN among women in South Africa.

Methods

The study used data obtained from the 2016 South African Demographic and Health Survey. In total, 6,027 women aged ≥ 20 years were analyzed in this study. Self-reported HTN was defined as a case in which an individual has not been clinically diagnosed with this chronic condition by a medical doctor, nurse, or health worker. Multiple logistic regression models were employed to examine the independent factors of self-reported HTN while considering the complex survey design.

Results

Overall, self-reported HTN was reported in 23.6% (95% confidence interval [CI], 23.1–24.1) of South African women. Being younger (adjusted odds ratio [aOR], 0.04; 95% CI, 0.03–0.06), never married (aOR, 0.69; 95% CI, 0.56–0.85), and not covered by health insurance (aOR, 0.74; 95% CI, 0.58–0.95) reduced the odds of self-reported HTN. On the other hand, being black/African (aOR, 1.73; 95% CI, 1.17–2.54), perception of being overweight (aOR, 1.72; 95% CI, 1.40–2.11), and perception of having poor health status (aOR, 3.53; 95% CI, 2.53–5.21) and the presence of other comorbidities (aOR, 7.92; 95% CI, 3.63–17.29) increased the odds of self-reported HTN.

Conclusions

Self-reported HTN was largely associated with multiple sociodemographic, health, and lifestyle factors and the presence of other chronic conditions. Health promotion and services aiming at reducing the burden of HTN in South Africa should consider the associated factors reported in this study to ensure healthy aging and quality of life among women.

Diabetic proximal tubulopathy: Can we mimic the disease for in vitro screening of SGLT inhibitors?

Diabetic kidney disease (DKD) is the foremost cause of renal failure. While the glomeruli are severely affected in the course of the disease, the main determinant for disease progression is the tubulointerstitial compartment. DKD does not develop in the absence of hyperglycemia. Since the proximal tubule is the major player in glucose reabsorption, it has been widely studied as a therapeutic target for the development of new therapies. Currently, there are several proximal tubule cell lines available, being the human kidney-2 (HK-2) and human kidney clone-8 (HKC-8) cell lines the ones widely used for studying mechanisms of DKD. Studies in these models have pushed forward the understanding on how DKD unravels, however, these cell culture models possess limitations that hamper research, including lack of transporters and dedifferentiation. The sodium-glucose cotransporters (SGLT) are identified as key players in glucose reabsorption and pharmacological inhibitors have shown to be beneficial for the long-term clinical outcome in DKD. However, their mechanism of action has, as of yet, not been fully elucidated. To comprehend the protective effects of SGLT inhibitors, it is essential to understand the complete functional, structural, and molecular features of the disease, which until now have been difficult to recapitulate. This review addresses the molecular events of diabetic proximal tubulopathy. In addition, we evaluate the protective role of SGLT inhibitors in cardiovascular and renal outcomes, and provide an overview of various in vitro models mimicking diabetic proximal tubulopathy used so far. Finally, new insights on advanced in vitro systems to surpass past limitations are postulated.

Application of machine learning methods for the development of antidiabetic drugs

Diabetes is a chronic non-communicable disease caused by several different routes, which has attracted increasing attention. In order to speed up the development of new selective drugs, machine learning (ML) technology has been applied in the process of diabetes drug development, which opens up a new blueprint for drug design. This review provides a comprehensive portrayal of the application of ML in antidiabetic drug use.

SGLT2 inhibitors, an accomplished development in field of medicinal chemistry: an extensive review

Diabetes is a chronic progressive metabolic disease caused by insulin deficiency or insulin resistance. In spite of the availability of several antihyperglycaemics, there is a need for the development of safer antidiabetic drugs due to their undesirable effects. Sodium-glucose cotransporter-2 inhibitors are a class of antidiabetics, which hinder the reabsorption of glucose in the kidneys, causing excretion of glucose via urine. Sodium-glucose cotransporter-2 inhibitors are a well-tolerated class with no significant adverse effects and are found to be favorable in certain conditions, which may be rudimentary to cardiovascular and renal diseases. The current advancements in their design and development, their mechanism of action, structure–activity relationship, synthesis and in silico development along with their auxiliary roles have been extensively reviewed.

SGLT2 Inhibitors: Emerging Roles in the Protection Against Cardiovascular and Kidney Disease Among Diabetic Patients

PURPOSE OF REVIEW

Type 2 diabetes mellitus (T2DM) is a prevalent disease with the severe clinical implications including myocardial infarction, stroke, and kidney disease. Therapies focusing on glycemic control in T2DM such as biguanides, sulfonylureas, thiazolidinediones, and insulin-based regimens have largely failed to substantially improve cardiovascular and kidney outcomes. We review the recent findings on sodium-glucose co-transporter type 2 (SGLT2) inhibitors which have shown to have beneficial cardiovascular and kidney-related effects.

RECENT FINDINGS

SGLT2 inhibitors are a new class of diabetic medications that reduce the absorption of glucose in the kidney, decrease proteinuria, control blood pressure, and are associated with weight loss. SGLT2 inhibitors provide complementary therapy independent of insulin secretion or action with proved glucose-lowering effects. Recent placebo-controlled clinical trials have demonstrated that these medications can decrease cardiovascular death, progression of kidney disease, and all-cause mortality in diabetic and non-diabetic patients. Interestingly, SGT2 inhibitors such as dapagliflozin have also proven to decrease heart failure admissions and cardiovascular endpoints in non-diabetic patients, suggesting pleiotropic effects. The exact mechanisms responsible for reductions in atherosclerotic heart disease, need for kidney replacement therapy, and progressive kidney disease remain unknown. While regulation of glomerular hyperfiltration, albuminuria, and natriuresis may be part of the explanation, it is possible that complex cellular effects including energy balance optimization, downregulation of oxidative stress, and modulation of pro-inflammatory signaling pathways are associated with favorable outcomes observed in large clinical studies.

CONCLUSION

SGLT2 inhibitors are novel antidiabetic medications with immense utility in the management of patients with T2DM. Furthermore, SGLT2 inhibitors have demonstrated to reduce the progression to advanced forms of kidney disease and its associated complications. These medications should be front and center in the management of patients with diabetic kidney disease with and without chronic kidney disease as they confer protection against cardiovascular/renal death and improve all-cause mortality. Future studies should evaluate the benefits and implications of early initiation of SGLT2 inhibitors, as well as the long-term effects of this therapy.

Sodium-glucose cotransporter 2 inhibitors (SGLT2i): renal implications

Type 2 diabetes mellitus (DM2) is a chronic condition that affects more than 400 million individuals worldwide. In DM2 patients, an appropriate glycemic control slows the onset and delays the progression of all its micro and macrovascular complications. Even though there are several glucose-lowering drugs, only approximately half of patients achieve glycemic control, while undesirable adverse effects (e.g., low serum glucose) normally affect treatment. Therefore, there is a need for new types of treatments. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have just been developed for treating DM2. Renal hyperfiltration as a marker of increased intraglomerular pressure in diabetic patients, and the role of renin-angiotensin-aldosterone system (RAAS) in this phenomenon have been studied. Nevertheless, RAAS blockade does not completely reduce hyperfiltration or diabetic renal damage. In this sense, the contribution of renal tubular factors to the hyperfiltration state, including sodium-glucose cotransporter (SGLT), has been currently studied. SGLT2i reduce proximal tubular sodium reabsorption, therefore increasing distal sodium delivery to the macula densa, causing tubule-glomerular feedback activation, afferent vasoconstriction, and reduced hyperfiltration in animal models. In humans, SGLT2i was recently shown to reduce hyperfiltration in normotensive, normoalbuminuric patients suffering from type 1 diabetes mellitus. In DM2 clinical trials, SGLT2 is associated with significant hyperfiltration and albuminuria reduction. The aim of this article is to compile the information regarding SGLT2i drugs, emphasizing its mechanism of renal repercussion.

[Advantages of therapy with sodium glucose cotransporter type 2 inhibitors in patients with type 2 diabetes mellitus in combination with hyperuricemia and gout]

Currently, only two drugs for reducing uric acid (UA), allopurinol and febuxostat, are registered in the Russian Federation, but their use does not allow to achieve the target level of UA in all cases. According to the results of numerous randomized trials, hyperuricemia and gout are associated with the corresponding components of the metabolic syndrome, including diabetes mellitus. The influence of factors is due to the need to search for new drugs that have a complex effect on several components of metabolic syndrome at once. Potentially attractive in this regard is a new group of drugs for the treatment of type 2 diabetes mellitus inhibitors of the sodium-glucose cotransporter of type 2, which, in addition to the main hypoglycemic actions, showed positive effects on the cardiovascular system, kidneys, as well as lowering UA.

Renal protective effects of empagliflozin via inhibition of EMT and aberrant glycolysis in proximal tubules

Sodium glucose cotransporter 2 (SGLT2) inhibitors are beneficial in halting diabetic kidney disease; however, the complete mechanisms have not yet been elucidated. The epithelial-mesenchymal transition (EMT) is associated with the suppression of sirtuin 3 (Sirt3) and aberrant glycolysis. Here, we hypothesized that the SGLT2 inhibitor empagliflozin restores normal kidney histology and function in association with the inhibition of aberrant glycolysis in diabetic kidneys. CD-1 mice with streptozotocin-induced diabetes displayed kidney fibrosis that was associated with the EMT at 4 months after diabetes induction. Empagliflozin intervention for 1 month restored all pathological changes; however, adjustment of blood glucose by insulin did not. Empagliflozin normalized the suppressed Sirt3 levels and aberrant glycolysis that was characterized by HIF-1α accumulation, hexokinase 2 induction, and pyruvate kinase isozyme M2 dimer formation in diabetic kidneys. Empagliflozin also suppressed the accumulation of glycolysis byproducts in diabetic kidneys. Another SGLT2 inhibitor, canagliflozin, demonstrated similar in vivo effects. High-glucose media induced the EMT, which was associated with Sirt3 suppression and aberrant glycolysis induction, in the HK2 proximal tubule cell line; SGLT2 knockdown suppressed the EMT, with restoration of all aberrant functions. SGLT2 suppression in tubular cells also inhibited the mesenchymal transition of neighboring endothelial cells. Taken together, SGLT2 inhibitors exhibit renoprotective potential that is partially dependent on the inhibition of glucose reabsorption and subsequent aberrant glycolysis in kidney tubules.

Pathophysiology of Type 2 Diabetes in Children and Adolescents

BACKGROUND

The prevalence of type 2 diabetes (DM) in children is disturbingly increasing in parallel with the increasing childhood obesity. Better knowledge regarding the pathophysiology of type 2 DM in children is paramount to devise an effective management plan.

OBJECTIVE

Discuss the pathophysiology of type 2 DM in children and adolescents.

METHODS AND RESULTS

This is a comprehensive review of the literature on this topic. Type 2 DM in childhood is viewed as a continuum of insulin resistance (IR) which is determined by an underlying genetic predisposition, intrauterine environment, excessive food consumption, continued rapid weight gain, and poor lifestyle. Besides IR, this is compounded by multiple metabolic defects including β-cell dysfunction and inadequate insulin secretion, α-cell dysfunction, hyperglucagonemia and increased hepatic glucose production, lipotoxicity, inflammation, deficiencies in incretin production and action, and increased renal glucose reabsorption. The confluence of genetic and environmental factors underscores the complexity in disease progression.

CONCLUSION

A consistent single risk factor for type 2 DM is obesity and related IR and therefore it is essential to curtail the progression of obesity. It is important to investigate the role of stringent dietary and nutritional approaches, medications that enhance β-cell function and insulin sensitivity.

The Role of DPP-4 Inhibitors in the Treatment Algorithm of Type 2 Diabetes Mellitus: When to Select, What to Expect

Type 2 diabetes mellitus is a growing global public health problem, the prevalence of which is projected to increase in the succeeding decades. It is potentially associated with many complications, affecting multiple organs and causing a huge burden to the society. Due to its multi-factorial pathophysiology, its treatment is varied and based upon a multitude of pharmacologic agents aiming to tackle the many aspects of the disease pathophysiology (increasing insulin availability [either through direct insulin administration or through agents that promote insulin secretion], improving sensitivity to insulin, delaying the delivery and absorption of carbohydrates from the gastrointestinal tract, or increasing urinary glucose excretion). DPP-4 (dipeptidyl peptidase-4) inhibitors (or “gliptins”) represent a class of oral anti-hyperglycemic agents that inhibit the enzyme DPP-4, thus augmenting the biological activity of the “incretin” hormones (glucagon-like peptide-1 [GLP-1] and glucose-dependent insulinotropic polypeptide [GIP]) and restoring many of the pathophysiological problems of diabetes. They have already been used over more than a decade in the treatment of the disease. The current manuscript will review the mechanism of action, therapeutic utility, and the role of DPP-4 inhibitors for the treatment of type 2 diabetes mellitus.

Effect of Dapagliflozin Treatment on the Expression of Renal Sodium Transporters/Channels on High-Fat Diet Diabetic Mice

BACKGROUND

Inhibition of the Na+/glucose co-transporter 2 is a new therapeutic strategy for diabetes. It is unclear how proximal loss of Na+ (and glucose) affects the subsequent Na+ transporters in the proximal tubule (PT), thick ascending limb of loop of Henle (TAL), distal convoluted tubule (DCT) and collecting duct (CD).

METHODS

Mice on a high fat diet were administered 3 doses streptozotocin 6 days prior to oral dapagliflozin administration or vehicle for 18 days. A control group of lean mice were also included. Body weight and glucose were recorded at regular intervals during treatment. Renal Na+ transporters expression in nephron segments were analyzed by RT-qPCR and Western blot.

RESULTS

Dapagliflozin treatment resulted in a significant reduction in body weight and blood glucose compared to vehicle-treated controls. mRNA results showed that Na+-hydrogen antiporter 3 (NHE3), Na+/phosphate cotransporter (NaPi-2a) and epithelial Na+ channel expression was increased, Ncx1, ENaCβ and ENaCγ expression declined (p all < 0.05), respectively, in dapagliflozin-treated mice when compared with saline vehicle mice. Na-K-2Cl cotransporters and Na-Cl cotransporter mRNA expression was not affected by dapagliflozin treatment. Na+/K+-ATPase (Atp1b1) expression was also increased significantly by dapagliflozin treatment, but it did not affect Atp1a1 and glucose transporter 2 expression. Western blot analysis showed that NaPi-2a, NHE3 and ATP1b1 expression was upregulated in dapagliflozin-treated diabetic mice when compared with saline vehicle mice (p < 0.05).

CONCLUSION

Our findings suggest that dapagliflozin treatment augments compensatory changes in the renal PT in diabetic mice.

Distribution of glucose transporters in renal diseases

Kidneys play an important role in glucose homeostasis. Renal gluconeogenesis prevents hypoglycemia by releasing glucose into the blood stream. Glucose homeostasis is also due, in part, to reabsorption and excretion of hexose in the kidney.Lipid bilayer of plasma membrane is impermeable for glucose, which is hydrophilic and soluble in water. Therefore, transport of glucose across the plasma membrane depends on carrier proteins expressed in the plasma membrane. In humans, there are three families of glucose transporters: GLUT proteins, sodium-dependent glucose transporters (SGLTs) and SWEET. In kidney, only GLUTs and SGLTs protein are expressed. Mutations within genes that code these proteins lead to different renal disorders and diseases. However, diseases, not only renal, such as diabetes, may damage expression and function of renal glucose transporters.

SGLT2-inhibitor and DPP-4 inhibitor improve brain function via attenuating mitochondrial dysfunction, insulin resistance, inflammation, and apoptosis in HFD-induced obese rats

Dipeptidyl peptidase-4 inhibitor (vildagliptin) has been shown to exert beneficial effects on insulin sensitivity and neuroprotection in obese-insulin resistance. Recent studies demonstrated the neuroprotection of the sodium-glucose co-transporter 2 inhibitor (dapagliflozin) in diabetes. However, the comparative effects of both drugs and a combination of two drugs on metabolic dysfunction and brain dysfunction impaired by the obese-insulin resistance have never been investigated. Forty male Wistar rats were divided into two groups, and received either a normal-diet (ND, n=8) or a high-fat diet (HFD, n=32) for 16weeks. At week 13, the HFD-fed rats were divided into four subgroups (n=8/subgroup) to receive either a vehicle, vildagliptin (3mg/kg/day) dapagliflozin (1mg/kg/day) or combined drugs for four weeks. ND rats were given a vehicle for four weeks. Metabolic parameters and brain function were investigated. The results demonstrated that HFD rats developed obese-insulin resistance and cognitive decline. Dapagliflozin had greater efficacy on improved peripheral insulin sensitivity and reduced weight gain than vildagliptin. Single therapy resulted in equally improved brain mitochondrial function, insulin signaling, apoptosis and prevented cognitive decline. However, only dapagliflozin improved hippocampal synaptic plasticity. A combination of the drugs had greater efficacy in improving brain insulin sensitivity and reducing brain oxidative stress than the single drug therapy. These findings suggested that dapagliflozin and vildagliptin equally prevented cognitive decline in the obese-insulin resistance, possibly through some similar mechanisms. Dapagliflozin had greater efficacy than vildagliptin for preserving synaptic plasticity, thus combined drugs could be the best therapeutic approach for neuroprotection in the obese-insulin resistance.

WITHDRAWN: The Role of Sodium-Glucose Cotransporter 2 Inhibitors in the Management of Type 2 Diabetes

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.jcjd.2016.11.008. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Comparative pharmacokinetics of three SGLT-2 inhibitors sergliflozin, remogliflozin and ertugliflozin: an overview

1. Several sodium-glucose cotransporter-2 (SGLT-2) inhibitors are in clinical use for the management of type 2 diabetes. The objectives of the current review were: (a) to provide a comparative pharmacokinetics including absorption, distribution, metabolism and excretory (ADME) profiles of three SGLT-2 inhibitors namely: sergliflozin, remogliflozin and ertugliflozin; (b) to provide some perspectives on possible developmental issues. 2. Based on the half-life (t_1/2) values observed in humans, the rank order of the three SGLT-2 inhibitors was ertugliflozin (16 h) > remogliflozin (2-4 h) > sergliflozin (1-1.5 h). Therefore, while once a day dosing of ertugliflozin is possible, the other two drugs need to be dosed more frequently. Perhaps, the short t_1/2 of sergliflozin may have contributed for its discontinuation. 3. Although there was paucity of published data on the metabolism, transporter related and excretory aspects for sergliflozin, the other two drugs provided a differentiating profile. However, the compiled data suggested that there may be a minimal or no risk of pharmacokinetic drug interaction issues associated with any of the reviewed drugs. 4. Because of the crowded development pipeline and approved SGLT-2 inhibitors, the safety and efficacy of sergliflozin, remogliflozin and ertugliflozin appear to be a key from differentiation perspective.

Functional imaging of pharmacological action of SGLT2 inhibitor ipragliflozin via PET imaging using 11C-MDG

Sodium‐dependent glucose cotransporter 2 (SGLT2) is a pharmacological target of type 2 diabetes mellitus. The aim of this study was to noninvasively visualize the pharmacological action of a selective SGLT2 inhibitor ipragliflozin in the kidney using positron emission tomography (PET) imaging with ¹¹C‐methyl‐d‐glucoside (¹¹C‐MDG), an SGLT‐specific radio‐labeled substrate. PET imaging with ¹¹C‐MDG in vehicle‐treated rats demonstrated that intravenously injected ¹¹C‐MDG substantially accumulated in the renal cortex, reflecting that the compound was reabsorbed by SGLTs. In contrast, ipragliflozin‐treated rats showed significantly lower uptake of ¹¹C‐MDG in renal cortex in a dose‐related manner, suggesting that ipragliflozin inhibited the renal reabsorption of ¹¹C‐MDG. This method of visualizing the mode of action of an SGLT2 inhibitor in vivo has demonstrated the drug's mechanism in reducing renal glucose reabsorption in kidney in living animals.