Sodium glucose transporter protein 2 inhibitors: focusing on the kidney to treat type 2 diabetes

The relationship between SGLT2 and systemic blood pressure regulation

The sodium-glucose cotransporter 2 (SGLT2) is a glucose transporter that is located within the proximal tubule of the kidney's nephrons. While it is typically associated with the kidney, it was later identified in various areas of the central nervous system, including areas modulating cardiorespiratory regulation like blood pressure. In the kidney, SGLT2 functions by reabsorbing glucose from the nephron's tubule into the bloodstream. SGLT2 inhibitors are medications that hinder the function of SGLT2, thus preventing the absorption of glucose and allowing for its excretion through the urine. While SGLT2 inhibitors are not the first-line choice, they are given in conjunction with other pharmaceutical interventions to manage hyperglycemia in individuals with diabetes mellitus. SGLT2 inhibitors also have a surprising secondary effect of decreasing blood pressure independent of blood glucose levels. The implication of SGLT2 inhibitors in lowering blood pressure and its presence in the central nervous system brings to question the role of SGLT2 in the brain. Here, we evaluate and review the function of SGLT2, SGLT2 inhibitors, their role in blood pressure control, the future of SGLT2 inhibitors as antihypertensive agents, and the possible mechanisms of SGLT2 blood pressure control in the central nervous system.

Efficacy and safety of luseogliflozin in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

PURPOSE

Owing to the absence of the most recent evidence on the efficacy and safety of luseogliflozin, our study aimed to conduct a systematic review and meta-analysis of luseogliflozin in patients with type 2 diabetes mellitus.

METHODS

A comprehensive search of electronic databases like PubMed, Cochrane CENTRAL, and Google Scholar was performed from the inception to the 31st of August 2023 to identify the randomized controlled trials (RCTs) that examined the glucose and body weight lowering efficacy and safety outcomes of luseogliflozin in comparison with control or other active treatments. The fixed or random-effect model was used based on the heterogeneity identified using the I2 statistic and Cochran's Q test.

RESULTS

Out of 50 non-duplicate articles identified through database searching, 8 RCTs (11 studies) with 1922 patients were included in this study. The efficacy outcomes like HbA1c (MD: -0.59%; 95% CI: -0.90, -0.29; P < 0.001), FPG (MD: -16.01 mg/dL; 95% CI: -19.46, -12.57; P < 0.001), PPG (MD: -36.63 mg/dL; 95% CI: -43.71, -29.55; P < 0.001) and body weight (MD: -1.66 kg; 95% CI: -2.23, -1.12; P < 0.001) were significantly reduced with luseogliflozin compared to the control group. Regarding the safety outcomes, there was no statistically significant difference between the two groups for hypoglycemia (OR: 1.14; 95% CI: 0.70, 1.84; P = 0.60). However, pollakiuria (OR: 4.08; 95% CI: 1.71, 9.69; P < 0.001) and any ADRs (OR: 2.04; 95% CI: 1.33, 3.14; P < 0.001) were significantly higher in the luseogliflozin group compared to the control.

CONCLUSION

The current study identified a significant improvement in efficacy outcomes of HbA1c, FPG, PPG, and body weight in the luseogliflozin group. Non-significant safety results may be due to a smaller population size and fewer studies. Hence, long-term multicentric RCTs are needed to identify the safety and efficacy in a diversified population.

Efficacy and safety of luseogliflozin in Caucasian patients with type 2 diabetes: results from a phase III, randomized, placebo-controlled, clinical trial

INTRODUCTION

Most data demonstrating the efficacy and safety of luseogliflozin (luseo) in people with type 2 diabetes mellitus (T2DM) originate from the Japanese population. This study evaluated luseo versus placebo (PCB) as add-on to metformin in a Caucasian population with inadequately controlled T2DM.

RESEARCH DESIGN AND METHODS

This was a multicenter, randomized, double-blind, PCB-controlled, parallel-group study. Patients aged 18-75 years with inadequately controlled T2DM (glycated hemoglobin (HbA1c) ≥7% to ≤10% (≥53 to ≤86 mmol/mol)) despite a diet and exercise program and on a stable metformin regimen were eligible. Patients were randomized to one of three luseo groups (2.5, 5.0 and 10.0 mg) or PCB for 12 weeks (W12). The primary endpoint was change in HbA1c expressed as least-square means from baseline (W0) to W12.

RESULTS

A total of 328 patients were randomized: PCB (n=83) and luseo 2.5 mg (n=80), 5.0 mg (n=86), and 10.0 mg (n=79). Mean age (±SD) was 58.5±8.8 years; 64.6% were women; body mass index was 31.5±3.4 kg/m2; and HbA1c was 8.54±0.70. At W12, mean reductions in HbA1c from W0 were -0.98%, -1.09%, -1.18%, and -0.73% in the luseo 2.5, 5.0 and 10.0 mg, and PCB groups, respectively, all of which were statistically significant. Compared with PCB, HbA1c levels were significantly decreased by 0.25% (p=0.045), 0.36% (p=0.006), and 0.45% (p=0.001) in the luseo 2.5, 5.0, and 10.0 mg groups, respectively. In all luseo dose groups, reductions in body weight were statistically significant compared with PCB. Data from the safety analysis were consistent with the known luseo safety profile.

CONCLUSIONS

All doses of luseo as add-on to metformin in Caucasian patients with uncontrolled T2DM demonstrated significant efficacy in decreasing HbA1c after W12 of treatment.

TRIAL REGISTRATION NUMBER

ISRCTN39549850.

Managing weight and glycaemic targets in people with type 2 diabetes—How far have we come?

Introduction

As the vast majority of people with type 2 diabetes (T2D) are also overweight or obese, healthcare professionals (HCP) are faced with the task of addressing both weight management and glucose control. In this narrative review, we aim to identify the challenges of reaching and maintaining body weight targets in people with T2D and highlight current and future treatment interventions.

Methods

A search of the PubMed database was conducted using the search terms “diabetes” and “weight loss.”

Results

According to emerging evidence, treating obesity may be antecedent to the development and progression of T2D. While clinical benefits typically set in upon achieving a weight loss of 3–5%, these benefits are progressive leading to further health improvements, and weight loss of >15% can have a disease‐modifying effect in people with T2D, an outcome that up to recently could not be achieved with any blood glucose‐lowering pharmacotherapy. However, advanced treatment options with weight‐loss effects currently in development including the dual GIP/GLP‐1 receptor agonists may enable simultaneous achievement of individual glycemic and weight goals.

Conclusion

Despite considerable therapeutic progress, there is still a large unmet medical need in patients with T2D who miss their individualized glycemic and weight‐loss targets. Nonetheless, it is to be expected that development of future therapies and their use will favourably change the scenario of weight and glucose control in T2D.

Protective effect of dapagliflozin against cyclosporine A-induced nephrotoxicity

This study aimed to reveal the possible protective effect of dapagliflozin (DAPA) against acute kidney damage due to cyclosporine A (CsA). Thirty-two mice with an eight-week-old Balb\c albino strain were divided into four groups: control group, CsA group, DAPA group, and CsA + DAPA group. On day 9 of treatment, the animals were decapitated, and bilateral nephrectomy was performed. Oxidative stress and apoptosis were evaluated with caspase-3 activity, total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA), myeloperoxidase (MPO), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax) in the right kidney resection material. The left kidney resection material was evaluated histopathologically. CsA increased caspase-3 activity, Bax, TOS, MDA, TAS, and MPO levels, and the administration of DAPA with CsA significantly reduced this increase in levels (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively). CsA decreased Bcl-2 levels, and administration of CsA + DAPA significantly increased Bcl-2 levels compared with only CsA administration (p < 0.001). Additionally, administration of DAPA significantly reduced the histopathological findings (parenchymal inflammation, hyaline cast formation, vacuolization, and lysis of renal tubular cells) caused by CsA. DAPA reduces oxidative stress, apoptosis, and histopathological damage caused by CsA in renal tissue.

Efficacy and safety of renal denervation for hypertension in patients with chronic kidney disease: a meta-analysis

BACKGROUND

Renal denervation (RDN) is a new treatment for hypertension in patients with chronic kidney disease (CKD), but its efficacy is still debated. This meta-analysis aimed to evaluate the efficacy and safety of RDN for hypertension in patients with CKD.

METHODS

PubMed, Web of Science, EMBASE, and Ovid databases were searched for relevant studies published. We performed both fixed- and random-effects meta-analyses of the changes in blood pressure, estimated glomerular filtration rate (eGFR), and urinary albumin-to-creatinine ratio (UACR) after RDN.

RESULTS

The meta-analysis included 238 patients from 11 single-center, non-randomized, uncontrolled studies. Office blood pressure and 24-hour ambulatory blood pressure (24 h-ABP) showed a significant reduction 1 month after RDN (p < 0.05). This decrease of 24 h-ABP persisted for 24 months after RDN showed difference systolic blood pressure (p < 0.001) and diastolic blood pressure (p = 0.001). The 24 h-ABP exhibited a similar trend in the subgroup analysis. eGFR measurements obtained at each time point of analysis after RDN were not significantly different from those obtained before (p > 0.05). UACR levels were significantly reduced at 3 months and 6 months after RDN (p < 0.001). After RDN, the heart rate showed no significant changes (p > 0.05), and few major complications were encountered.

CONCLUSIONS

The meta-analysis showed that RDN may be effective and safe for treating CKD patients with hypertension. Well-designed randomized controlled trials of RDN are urgently needed to confirm the safety and reproducibility of RDN and to assess its impact on clinical outcomes.

Signaling pathways and proteins targeted by antidiabetic chalcones

Chalcones have shown a broad spectrum of biological activities with clinical potential against various diseases. The biological activities are mainly attributed to the presence of α, β-unsaturated carbonyl system, perceived as potential Michael acceptors. In this review, we discussed the antioxidant potential of chalcones and elucidated the mechanisms of pathways and proteins such as carbohydrate digestive enzymes (α-amylase and α-glucosidase), aldose reductase, SGLT-2, and Nrf2 that are targeted by antidiabetic chalcones. In addition to their insulin mimetic potential, we explore the major molecular targets of chalcones and discuss the biochemical and therapeutic implication of modulating these targets. Finally, we dwell on the opulence of the literature and envisage how RNA interference-mediated gene silencing technique and in silico molecular docking could be exploited in the search for novel and more efficacious antidiabetic chalcones.

The Role of SGLT2 Inhibitor on the Treatment of Diabetic Retinopathy

Diabetic retinopathy (DR) is one of the most serious complications of diabetic microangiopathy. DR has an early onset and is not easy to detect. When visual impairment occurs, the optimal period for therapy is often missed. Therefore, the prevention and treatment of DR should start from the early stage of diabetes. Sodium-dependent glucose transporter 2 inhibitor (SGLT2i) is a new antidiabetic drug which is mainly used in clinical practice to control blood glucose of patients with type 2 diabetes prone to develop chronic heart failure. Recent studies have found that SGLT2 is also expressed in the human retina. Now, the prevention and treatment of diabetic retinopathy with SGLT2i while reducing blood sugar has become a new research field. Hence, this article reviewed the recent therapeutic and research progress of SGLT2 in the treatment of diabetic retinopathy.

Update on postprandial hyperglycaemia: the pathophysiology, prevalence, consequences and implications of treating diabetes

To achieve appropriate glycaemic control, postprandial and baseline hyperglycaemia should be reduced. Various epidemiological studies have suggested an association between fluctuations in postprandial blood glucose and cardiovascular risk. However, studies of interventions performed to date have not shown that selective control of postprandial hyperglycaemia is associated with cardiovascular benefits. Accordingly, an appropriate combination of drugs that control both baseline and postprandial hyperglycaemia (individually based on each patient's characteristics) is the best strategy for achieving good glycaemic control. This review seeks to impart to clinicians the concept of postprandial hyperglycaemia, analysing its causes, how to measure it, its prevalence, its consequences and, ultimately, the available therapeutic strategies for the preferential control of the postprandial hyperglycaemia along with baseline hyperglycaemia.

Adherence, Persistence, and Switching Among People Prescribed Sodium Glucose Co-transporter 2 Inhibitors: A Nationwide Retrospective Cohort Study

INTRODUCTION

Non-adherence and non-persistence to diabetes medications are associated with worse clinical outcomes. In this study, we aimed to characterise the 1-year switching, adherence, and persistence patterns among people with diabetes aged 18 years and older prescribed sodium-glucose co-transporter 2 inhibitors (SGLT2is) in Australia.

METHODS

Using data from Australia's national Pharmaceutical Benefits Scheme (PBS), we identified 11,981 adults (mean age 60.9 years; 40.5% female) newly initiated on SGLT2is (5993 dapagliflozin; 5988 empagliflozin) from September 2015 to August 2017. Adherence was assessed via the proportion of days covered (PDC), persistence was defined as the continuous use of SGLT2i without a gap of ≥ 90 days, and switching was defined as the first change from dapagliflozin to empagliflozin or vice versa. Generalised linear models (GLMs) were used to compare the adherence (PDC = continuous), logistic regression models were used to compare the likelihoods of being adherent (PDC ≥ 0.80), and Cox proportional hazard models were used to compare the likelihoods of persistence and switching between people prescribed empagliflozin and dapagliflozin.

RESULTS

Overall, 65.8% (7879/11,981) of people dispensed SGLT2is were adherent (PDC ≥ 0.80) and 72.1% (8644/11,981) were persistent at 12 months. The mean PDC was 0.79 ± 0.27. The use of empagliflozin was associated with higher adherence (PDC = continuous) [odds ratio (OR) 1.04, 95% confidence interval (CI) 1.03-1.05], being adherent (OR 1.39, 95% CI 1.29-1.51), and persisting for 12 months [hazard ratio (HR) 1.14, 95% CI 1.06-1.22] compared with dapagliflozin. Only 4.3% (509/11,981) of people switched between the SGLT2i. Compared with dapagliflozin, people initiated on empagliflozin were less likely to switch [HR 0.46, 95% CI 0.38-0.55].

CONCLUSIONS

A considerable proportion of Australians prescribed SGLT2is were non-adherent or non-persistent. However, empagliflozin was associated with better adherence and persistence rates and a lower likelihood of switching compared with dapagliflozin.

Canagliflozin review - safety and efficacy profile in patients with T2DM

Canagliflozin is a sodium glucose-cotransporter (SGLT) receptor inhibitor approved for the treatment of type 2 diabetes mellitus (T2DM). This article reviews the mechanism of action of SGLT-2 receptor inhibitors and the efficacy of canagliflozin as an antidiabetic agent, its cardiovascular and renal benefits, and safety profile. During the development of canagliflozin, Phase II trials showed an improvement in cardiac and renal biomarkers such as blood pressure, body weight, and albuminuria. The large CANVAS program showed that canagliflozin reduced the composite cardiovascular outcome of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. The CANVAS program also showed a possible benefit of canagliflozin on a renal composite of sustained 40% reduction in estimated glomerular filtration rate, the need for renal replacement therapy, or death from renal causes. The safety profile of canagliflozin has been well characterized, and known side effects such as mycotic genital infections were confirmed in CANVAS. However, an increased risk of amputations was observed in CANVAS that requires further study. Overall, canagliflozin is an effective antidiabetic medication with cardiovascular and likely renal benefits, and with a generally well-tolerated safety profile. Results from the CREDENCE trial will further evaluate the safety and potential renal benefits of canagliflozin in patients with established diabetic nephropathy.

Body Weight Considerations in the Management of Type 2 Diabetes

Obesity is one of the main risk factors for type 2 diabetes (T2D), representing a major worldwide health crisis. Modest weight-loss (≥ 5% but < 10%) can minimize and reduce diabetes-associated complications, and significant weight-loss can potentially resolve disease. Treatment guidelines recommend that intensive lifestyle interventions, pharmacologic therapy, and/or metabolic surgery be considered as options for patients with T2D and obesity. The benefits and risks of such interventions should be evaluated in the context of their weight-loss potential, ability to sustain weight change, side effect profile, and costs. Antihyperglycemia therapies have considerable effects on patient weight, prompting careful consideration of weight-loss or weight-neutral therapies for patients with T2D who also have obesity. Metformin, sodium glucose co-transporter 2 inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RAs), α-glucosidase inhibitors, and amylin mimetics promote weight-loss. Dipeptidyl peptidase-4 inhibitors and fixed-ratio insulin/GLP-1 RA combination therapies (IDegLira, iGlarLixi) appear to be weight-neutral. Thiazolidinediones, insulin secretagogues (sulfonylureas, meglitinides), and insulins are associated with weight gain. Sulfonylureas are additionally associated with a higher risk of serious hypoglycemia from hyperinsulinemia, making them less suitable for the treatment of patients who are overweight or have obesity. Patients are often overtitrated on basal insulin, resulting in an increased risk of hypoglycemia and weight gain without achieving glycemic goals. Given these observations, the effects of antihyperglycemia agents on weight should be considered when individualizing T2D therapy.Funding: Sanofi US, Inc.

Interaction Between the Sodium-Glucose-Linked Transporter 2 Inhibitor Dapagliflozin and the Loop Diuretic Bumetanide in Normal Human Subjects

Background

Dapagliflozin inhibits the sodium‐glucose–linked transporter 2 in the renal proximal tubule, thereby promoting glycosuria to reduce hyperglycemia in type 2 diabetes mellitus. Because these patients may require loop diuretics, and sodium‐glucose–linked transporter 2 inhibition causes an osmotic diuresis, we evaluated the diuretic interaction between dapagliflozin and bumetanide.

Methods and Results

Healthy subjects (n=42) receiving a fixed diet with ≈110 mmol·d⁻¹ of Na⁺ were randomized to bumetanide (1 mg·d⁻¹), dapagliflozin (10 mg·d⁻¹), or both for 7 days, followed by 7 days of both. There were no meaningful pharmacokinetic interactions. Na⁺ excretion increased modestly with the first dose of dapagliflozin (22±6 mmol·d⁻¹; P<0.005) but by more (P<0.005) with the first dose of bumetanide (74±7 mmol·d⁻¹; P<0.005), which was not significantly different from both diuretics together (80±5 mmol·d⁻¹; P<0.005). However, Na⁺ excretion with dapagliflozin was 190% greater (P<0.005) when added after 1 week of bumetanide (64±6 mmol·d⁻¹), and Na⁺ excretion with bumetanide was 36% greater (P<0.005) when added after 1 week of dapagliflozin (101±8 mmol·d⁻¹). Serum urate was increased 4% by bumetanide but reduced 40% by dapagliflozin or 20% by combined therapy (P<0.05).

Conclusions

First‐dose Na⁺ excretion with bumetanide and dapagliflozin is not additive, but the weekly administration of one diuretic enhances the initial Na⁺ excretion with the other, thereby demonstrating mutual adaptive natriuretic synergy. Combined therapy reverses bumetanide‐induced hyperuricemia. This requires further study in diabetic patients with hyperglycemia who have enhanced glycosuria and natriuresis with dapagliflozin.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00930865.

Dapagliflozin: potential beneficial effects in the prevention and treatment of renal and cardiovascular complications in patients with type 2 diabetes

INTRODUCTION

Diabetic kidney disease is the leading cause of end-stage renal disease, a significant contributor to cardiovascular (CV) disease, responsible for much of the morbidity and mortality in patients with type 2 diabetes (T2DM). Strategies to slow or prevent the onset and progression of diabetic kidney disease are critical for effectively managing T2DM and reducing CV risk. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are effective antidiabetic agents, which may provide nephroprotective and CV protective effects. Areas covered: This review examines the role of the kidney in glucose homeostasis, discusses renal hemodynamic changes in diabetes, and outlines the major hypotheses regarding the mechanisms underlying renal injury in diabetes. The potential benefits of SGLT2 inhibitors in the prevention and treatment of CV complications in patients with T2DM are reviewed, with particular focus on dapagliflozin. Expert opinion: Dapagliflozin and other SGLT2 inhibitors have the capacity to decrease hyperglycemia and visceral fat, components of the metabolic syndrome particularly associated with the progression of CV disease. However, the mechanisms of action of SGLT2 inhibitors resulting in their positive CV effects remain unclear. Furthermore, the mechanism of action of SGLT2 inhibitors on heart function in non-diabetic patients with decompensated heart failure remains to be explored.

Rationale for treatment options for mealtime glucose control in patients with type 2 diabetes

While glycemic control is routinely assessed using HbA1c and fasting glucose measures, postprandial glucose (PPG) is also an important contributor of overall glycemia. Furthermore, PPG excursions have been linked to complications of diabetes. This review examines the effects of glucose-lowering therapies (including treatments administered at mealtime) on postprandial hyperglycemia in patients with type 2 diabetes. A PubMed search was conducted to identify clinical studies of treatments for mealtime glucose control in type 2 diabetes. Different treatments may have comparable effects on HbA1c but varying effects on PPG control and glucose fluctuations. Older classes of oral glucose-lowering treatments administered at mealtime to lower PPG include meglitinides and α-glucosidase inhibitors. Injectable therapies, including prandial insulin analogs, glucagon-like peptide-1 receptor agonists (GLP-1RAs), and the amylin analog pramlintide, all effectively target postprandial hyperglycemia. Compared with longer-acting GLP-1RAs, short-acting GLP-1RAs, such as exenatide twice daily and lixisenatide once daily, have a greater effect on PPG control, which is primarily mediated by a more pronounced effect on delayed gastric emptying. Dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter 2 inhibitors also reduce postprandial hyperglycemia. To achieve more physiologically normal glycemic control, choice of therapy should ideally aim to address daily glucose fluctuations, including hyperglycemic peaks and hypoglycemic troughs, and long-term glycemic control.

Sodium and Its Role in Cardiovascular Disease - The Debate Continues

Guidelines have recommended significant reductions in dietary sodium intake to improve cardiovascular health. However, these dietary sodium intake recommendations have been questioned as emerging evidence has shown that there is a higher risk of cardiovascular disease with a low sodium diet, including in individuals with type 2 diabetes. This may be related to the other pleotropic effects of dietary sodium intake. Therefore, despite recent review of dietary sodium intake guidelines by multiple organizations, including the dietary guidelines for Americans, American Diabetes Association, and American Heart Association, concerns about the impact of the degree of sodium restriction on cardiovascular health continue to be raised. This literature review examines the effects of dietary sodium intake on factors contributing to cardiovascular health, including left ventricular hypertrophy, heart rate, albuminuria, rennin-angiotensin-aldosterone system activation, serum lipids, insulin sensitivity, sympathetic nervous system activation, endothelial function, and immune function. In the last part of this review, the association between dietary sodium intake and cardiovascular outcomes, especially in individuals with diabetes, is explored. Given the increased risk of cardiovascular disease in individuals with diabetes and the increasing incidence of diabetes worldwide, this review is important in summarizing the recent evidence regarding the effects of dietary sodium intake on cardiovascular health, especially in this population.

Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors and Cardiovascular Disease: A Systematic Review

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a novel class of drugs that have been extensively investigated for the treatment of hyperglycemia in type 2 diabetes mellitus (T2DM). These drugs reduce hyperglycemia by blocking renal glucose reabsorption, thereby promoting increased renal glucose excretion. Beyond glycemic control, these drugs have other beneficial effects on cardiovascular (CV) risk factors. The present review discusses the potential role of SGLT2 inhibitors in treating CV complications (acute and chronic) associated with T2DM.

FUNDING

AstraZeneca Pharma India Ltd.

New Pathogenic Concepts and Therapeutic Approaches to Oxidative Stress in Chronic Kidney Disease

In chronic kidney disease inflammatory processes and stimulation of immune cells result in overproduction of free radicals. In combination with a reduced antioxidant capacity this causes oxidative stress. This review focuses on current pathogenic concepts of oxidative stress for the decline of kidney function and development of cardiovascular complications. We discuss the impact of mitochondrial alterations and dysfunction, a pathogenic role for hyperuricemia, and disturbances of vitamin D metabolism and signal transduction. Recent antioxidant therapy options including the use of vitamin D and pharmacologic therapies for hyperuricemia are discussed. Finally, we review some new therapy options in diabetic nephropathy including antidiabetic agents (noninsulin dependent), plant antioxidants, and food components as alternative antioxidant therapies.

Interaction of the Sodium/Glucose Cotransporter (SGLT) 2 inhibitor Canagliflozin with SGLT1 and SGLT2

Canagliflozin, a selective sodium/glucose cotransporter (SGLT) 2 inhibitor, suppresses the renal reabsorption of glucose and decreases blood glucose level in patients with type 2 diabetes. A characteristic of canagliflozin is its modest SGLT1 inhibitory action in the intestine at clinical dosage. To reveal its mechanism of action, we investigated the interaction of canagliflozin with SGLT1 and SGLT2. Inhibition kinetics and transporter-mediated uptake were examined in human SGLT1- or SGLT2-expressing cells. Whole-cell patch-clamp recording was conducted to examine the sidedness of drug action. Canagliflozin competitively inhibited SGLT1 and SGLT2, with high potency and selectivity for SGLT2. Inhibition constant (Ki) values for SGLT1 and SGLT2 were 770.5 and 4.0 nM, respectively. (14)C-canagliflozin was suggested to be transported by SGLT2; however, the transport rate was less than that of α-methyl-d-glucopyranoside. Canagliflozin inhibited α-methyl-d-glucopyranoside-induced SGLT1- and SGLT2-mediated inward currents preferentially from the extracellular side and not from the intracellular side. Based on the Ki value, canagliflozin is estimated to sufficiently inhibit SGLT2 from the urinary side in renal proximal tubules. The Ki value for SGLT1 suggests that canagliflozin suppresses SGLT1 in the small intestine from the luminal side, whereas it does not affect SGLT1 in the heart and skeletal muscle, considering the maximal concentration of plasma-unbound canagliflozin. Similarly, SGLT1 in the kidney would not be inhibited, thereby aiding in the prevention of hypoglycemia. After binding to SGLT2, canagliflozin may be reabsorbed by SGLT2, which leads to the low urinary excretion and prolonged drug action of canagliflozin.

Efficacy and Safety of the SGLT2 Inhibitor Luseogliflozin in Japanese Patients With Type 2 Diabetes Mellitus Stratified According to Baseline Body Mass Index: Pooled Analysis of Data From 52-Week Phase III Trials

PURPOSE

Luseogliflozin, a sodium-glucose cotransporter-2 inhibitor, may be beneficial in obese diabetic patients based on its potential to decrease blood glucose and body weight, but there is limited proof. This analysis aimed to investigate the efficacy and safety of luseogliflozin in patients with varying levels of obesity.

METHODS

A pooled analysis of four 52-week Phase III trials of luseogliflozin 2.5 mg daily (or up to 5 mg daily) in Japanese patients with type 2 diabetes mellitus stratified according to baseline body mass index (BMI) was conducted. Efficacy end points included changes in glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), and body weight.

FINDINGS

In total, 1031 patients were included and stratified into 5 BMI (kg/m(2)) groups: low-to-medium (<22.5, n = 222); medium (≥22.5 to <25, n = 270); high-level 1 (≥25 to <27.5, n = 262); high-level 2 (≥27.5 to <30, n = 142); and very-high (≥30, n = 135). HbA1c decreased significantly compared with baseline until week 52 in all groups, and a similar trend was observed with FPG and body weight. The reduction in glycemic parameters tended to be slightly smaller in patients with BMI <22.5 kg/m(2), and the reduction in body weight tended to be greater in patients with higher BMI, especially those with BMI ≥30 kg/m(2). Levels of fasting insulin, C-peptide immunoreactivity, triglyceride, blood pressure, aspartate aminotransferase, alanine aminotransferase, and uric acid decreased significantly at week 52 in all groups (except for aspartate aminotransferase in patients with BMI <22.5 kg/m(2)). Levels of these parameters tended to be higher at baseline and these enhanced levels resulted in a greater decrease in patients with higher BMI. In safety, the incidence of adverse events was similar between groups, and most of them were mild in severity.

IMPLICATIONS

HbA1c and body weight decreased significantly in all groups. Decrease in glycemic parameters tended to be smaller in patients with BMI <22.5 kg/m(2), while that of body weight was larger in patients with higher BMI. Furthermore, luseogliflozin was especially beneficial in patients with higher BMI in terms of metabolic abnormalities, including insulin secretion and hypertension. Luseogliflozin exhibited a favorable and similar safety profile over 52 weeks in all groups. This agent can be an effective and well-tolerated therapeutic option in patients with a wide range of BMI levels, and it may be more beneficial in patients with higher BMI.

Impact of the 8-week Administration of Tofogliflozin for Glycemic Control and Body Composition in Japanese Patients with Type 2 Diabetes Mellitus

Objective The adverse effects of selective sodium-glucose co-transporter 2 (SGLT2) inhibitors generally appear within about two or three months after treatment initiation in Japan. Therefore, we investigated the impact of tofogliflozin, a class of SGLT2 inhibitors, on glycemic control and body composition during this period in Japanese patients with type 2 diabetes mellitus. Methods This single-arm open-label study enrolled 20 patients. Patients received tofogliflozin 20 mg once daily for 8 weeks. At week 8, changes from baseline in body weight, serum metabolic markers, and body composition were evaluated. Results A total of 17 patients completed the 8-week administration of tofogliflodin. No serious adverse events were noted. Hemoglobin A1c (HbA1c) decreased significantly, from 7.8% to 7.3% with 8-week administration of tofogliflozin. Both the body weight and body mass index (BMI) also decreased. In addition, a decreased renal function of the boundary zone and hemoconcentration were detected. As for body composition, the free fat mass, total body water, extracellular water and intracellular water were all decreased significantly. Interestingly, the amount of fat mass did not change. The degree of improvement in HbA1c was correlated with the baseline fat mass and BMI. Conclusion An eight-week administration of tofogliflozin improved glycemic control and reduced the body weight and free fat mass in type 2 diabetic patients without affecting the fat mass. In this period, the hematocrit level and renal function should be monitored to guard against hemoconcentration and renal impairment, respectively.

Model analysis of effect of canagliflozin (Invokana), a sodium-glucose cotransporter 2 inhibitor, to alter plasma 1,5-anhydroglucitol

BACKGROUND

Renal reabsorption of 1,5-anhydroglucitol (AG) is competitively inhibited by elevated glucose and leads to depleted plasma AG in diabetes. Plasma AG recovery in diabetes normally correlates with improved glycemic control. However, use of sodium-glucose co-transporter 2 (SGLT2) inhibitors (e.g., canagliflozin) to treat diabetes by inhibition of renal glucose reabsorption can negate this correlation, via an indirect effect (increase of renal filtrate glucose concentration) to inhibit AG reabsorption by sodium-glucose co-transporter 4 (SGLT4). Conversely, then, AG measurement might be useful as an independent marker for SGLT2 inhibitor activity.

METHODS

Using an AG mass balance model, we analyzed literature data on plasma AG before and after initiation of canagliflozin therapy (CT) to quantitatively characterize the effect of CT on AG reabsorption.

RESULTS

According to model calculations, modest decreases (<5%) in fractional reabsorption of AG account for the drastic decrease in [AG] observed during CT. Decreases are predicted to be rapid (t1/2<3days) after CT initiation.

CONCLUSION

CT negates the usual premise of AG measurement (that [AG] should increase with improved glycemic control). However, according to model calculations, a substantial and likely rapid effect of CT on [AG] means that AG measurement might provide an early marker for CT activity.

Cardiometabolic Effects of a New Class of Antidiabetic Agents

PURPOSE

Within the past decade, many new classes of drugs have received approval from the US Food and Drug Administration for treatment of type 2 diabetes mellitus, including glucagon-like peptide-1agonists, dipeptidyl peptidase-4 inhibitors, and the sodium-glucose cotransporter-2 inhibitors. Many trials have been performed, and several more are currently ongoing to evaluate these drugs. This review addresses the broad therapeutic and pleiotropic effects of these drugs. The review also discusses the role of these drugs in the treatment paradigm for type 2 diabetes and identifies patients who would be suitable candidates for treatment with these drugs.

METHODS

In this comprehensive evidence-based review, the following databases were searched from 1990 to the present: PubMed/MEDLINE, Scopus, CINAHL, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Portal, and the American Diabetes Association and European Association for the Study of Diabetes abstract databases. Randomized clinical trials (RCTs) were only included for the main therapeutic and cardiovascular (CV) effects of these drug classes. For pleiotropic effects, RCTs were included unless no RCTs exist, in which case other studies as specified in the detailed Methods section were included.

FINDINGS

All 3 drug classes are effective in lowering hemoglobin A1c between 0.4% and 1.4%, depending on the drug class and population selected. These drug classes have beneficial effects on CV risk factors, such as weight, lipids, and blood pressure, in addition to lowering blood glucose levels. The CV tolerability of some drugs has been evaluated and found to be neutral; however, most trials are currently ongoing to assess CV tolerability. There are no concrete guidelines to determine where these drugs fit in the diabetes management paradigm, and there are ongoing trials to determine the best combination drug with metformin.

IMPLICATIONS

These 3 drug classes will potentially increase the armamentarium against hyperglycemia. However, the specific combinations with other antidiabetic drugs and populations that will best benefit from these drugs are still being tested. Future research is also being conducted on the use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors in patients with type 1 diabetes.