Clinical potential of sodium-glucose cotransporter 2 inhibitors in the management of 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.

SGLT-2i and Risk of Malignancy in Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials

Background: Currently, the association between sodium-glucose cotransporter 2 inhibitor (SGLT-2i) and malignancy risk has yet to be fully elucidated. This meta-analysis aimed to determine the relationship between SGLT-2i and malignancy risk in type 2 diabetes (T2D) patients.

Methods: We searched PubMed, ScienceDirect, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science to identify randomized controlled trials (RCTs) published up to August 2020 related to T2D patients treated with SGLT-2i vs. placebo or other hypoglycemic agents. The meta-analysis's primary outcome was malignancies' incidence, and the results were evaluated using risk ratio (RR) and 95% confidence interval (CI).

Results: We reviewed 76 articles (77 RCTs), comprising 45,162 and 43,811 patients in SGLT-2i and control groups, respectively. Compared with the control group, SGLT-2i had no significant association with augmented overall malignancy risk in T2D patients (RR = 1.05, 95% CI = 0.97–1.14, P = 0.20), but ertugliflozin may upsurge the risk (RR = 1.80, 95% CI = 1.02–3.17, P = 0.04). Compared with active hypoglycemic agents, dapagliflozin may increase (RR = 2.71, 95% CI = 1.46–6.43, P = 0.02) and empagliflozin may decrease (RR = 0.67, 95% CI = 0.45–0.98, P = 0.04) the malignancy risk. Compared with placebo, empagliflozin may exhibit risk increase (RR = 1.25, 95% CI = 1.05–1.49, P = 0.01), primarily in digestive system (RR = 1.48, 95% CI = 0.99–2.21, P = 0.05).

Conclusions: Our results proposed that in diverse comparisons, ertugliflozin and dapagliflozin seemed to increase the malignancy risk in T2D patients. Empagliflozin may cause malignancy risk reduction compared with active hypoglycemic agents but increase overall risk primarily in the digestive system compared with placebo. In short, the relationship between SGLT-2i and malignancy in T2D patients remains unclear.

Blood Pressure-Lowering Effect of Newer Antihyperglycemic Agents (SGLT-2 Inhibitors, GLP-1 Receptor Agonists, and DPP-4 Inhibitors)

The prevalence of arterial hypertension is high in patients with diabetes mellitus (DM). When DM and hypertension coexist, they constitute a dual cardiovascular threat and should be adequately controlled. Novel antihyperglycemic agents, including sodium-glucose co-transporter 2 (SGLT-2) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1 RAs), and dipeptidyl peptidase-4 (DPP-4) inhibitors, have recently been used in the treatment of DM. Beyond their glucose-lowering effects, these drugs have shown beneficial pleiotropic cardiovascular effects, including lowering of arterial blood pressure (BP), as acknowledged in the 2019 European Society of Cardiology/European Association for the Study of Diabetes guidelines on diabetes, prediabetes, and cardiovascular diseases. The purpose of this review was to summarize the available information on the BP-reducing effects of these new glucose-lowering drug classes and provide a brief report on underlying pathophysiological mechanisms. We also compare the three drug classes (SGLT-2 inhibitors, GLP-1 RAs, and DPP-4 inhibitors) in terms of their BP-lowering effect and show that the greater BP reduction seems to be achieved with SGLT-2 inhibitors, whereas DPP-4 inhibitors have probably the mildest antihypertensive effect.

1,5-anhydroglucitol is a good predictor for the treatment effect of the Sodium-Glucose cotransporter 2 inhibitor in Japanese patients with type 2 diabetes mellitus

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1,5-AG is the novel predictor of HbA1c reduction with SGLT2 inhibitors.

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1,5-AG is a useful predictor that is unaffected by the use of other diabetic drugs.

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The most appropriate 1,5-AG cutoff level is 7.65 µg/mL.

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In patients with 1,5-AG >7.7 µg/mL, SGLT2 inhibitors do not reduce HbA1c as much.

Background and Aims

The suitable selection of appropriate medicines is one of important factor in successful diabetes care. We looked for clinical indicators that could predict the effects of SGLT2 inhibitors in advance.

Methods and Results

In a single-center, this retrospective study was designed to examine predictive indices of the effectiveness of SGLT2 inhibitors. Using the medical records of 169 patients, we investigated the differences in clinical data between a group with improved glycemic control and a group with less improved glycemic control. 32 weeks of treatment with SGLT2 inhibitors decreased the HbA1c levels by 0.71%. The glucose-lowering effect was associated with improvement of the liver function. The maximum BMI change was independent of the rate of the HbA1c reduction. The HbA1c reduction was greater in patients with low 1,5-AG. This determination was unaffected by the use of anti-diabetic medication. Limiting HbA1c from 7.0% (52 mmol/mol) to 8.4% (68 mmol/mol) did not change this tendency. The maximum sum of sensitivity and specificity for patients with an HbA1c improvement of more than 0.7% was obtained with a 1,5-AG cutoff level of 7.65 µg/mL.

Conclusion

The use of SGLT2 inhibitors in patients with T2DM, 1,5-AG was identified as the most reliable indicator for predicting HbA1c reduction.

Human-induced pluripotent stem cells for modelling metabolic perturbations and impaired bioenergetics underlying cardiomyopathies

Normal cardiac contractile and relaxation functions are critically dependent on a continuous energy supply. Accordingly, metabolic perturbations and impaired mitochondrial bioenergetics with subsequent disruption of ATP production underpin a wide variety of cardiac diseases, including diabetic cardiomyopathy, dilated cardiomyopathy, hypertrophic cardiomyopathy, anthracycline cardiomyopathy, peripartum cardiomyopathy, and mitochondrial cardiomyopathies. Crucially, there are no specific treatments for preventing the onset or progression of these cardiomyopathies to heart failure, one of the leading causes of death and disability worldwide. Therefore, new treatments are needed to target the metabolic disturbances and impaired mitochondrial bioenergetics underlying these cardiomyopathies in order to improve health outcomes in these patients. However, investigation of the underlying mechanisms and the identification of novel therapeutic targets have been hampered by the lack of appropriate animal disease models. Furthermore, interspecies variation precludes the use of animal models for studying certain disorders, whereas patient-derived primary cell lines have limited lifespan and availability. Fortunately, the discovery of human-induced pluripotent stem cells has provided a promising tool for modelling cardiomyopathies via human heart tissue in a dish. In this review article, we highlight the use of patient-derived iPSCs for studying the pathogenesis underlying cardiomyopathies associated with metabolic perturbations and impaired mitochondrial bioenergetics, as the ability of iPSCs for self-renewal and differentiation makes them an ideal platform for investigating disease pathogenesis in a controlled in vitro environment. Continuing progress will help elucidate novel mechanistic pathways, and discover novel therapies for preventing the onset and progression of heart failure, thereby advancing a new era of personalized therapeutics for improving health outcomes in patients with cardiomyopathy.

There is a Close Association Between the Recovery of Liver Injury and Glycemic Control after SGLT2 Inhibitor Treatment in Japanese Subjects with Type 2 Diabetes: A Retrospective Clinical Study

INTRODUCTION

Sodium-glucose co-transporter 2 (SGLT2) inhibitors function not only to reduce hyperglycemia but also to ameliorate liver injury and reduce body weight. The aim of this study was to examine in which subjects SGLT2 inhibitors are more effective for glycemic control, liver injury, and obesity in Japanese subjects with type 2 diabetes mellitus.

METHODS

We enrolled a total of 156 subjects with type 2 diabetes who initiated SGLT2 inhibitor treatment after September 1, 2014 in Kawasaki Medical School (Protocol No. 2375). We evaluated the alteration of glycemic control, liver injury, body mass composition, and various clinical parameters.

RESULTS

SGLT2 inhibitors significantly ameliorated glycemic control and improved liver injury in Japanese subjects with type 2 diabetes. SGLT2 inhibitors were more effective for liver injury when glycemic control was improved with SGLT2 inhibitors. In multivariate analyses, the amelioration of glycemic control was an independent determinant factor for the improvement of liver damage in Japanese subjects with type 2 diabetes. The reverse was also correct; the improvement of liver damage was an independent determinant factor for the amelioration of glycemic control.

CONCLUSION

Recovery of liver injury with SGLT2 inhibitor treatment was closely associated with their effects on glycemic control in Japanese subjects with type 2 diabetes.

Long-term safety and efficacy of tofogliflozin as add-on to insulin in patients with type 2 diabetes: Results from a 52-week, multicentre, randomized, double-blind, open-label extension, Phase 4 study in Japan (J-STEP/INS)

AIMS

To evaluate the long-term safety and efficacy of tofogliflozin as an add-on treatment to insulin over 52 weeks.

MATERIALS AND METHODS

This 52-week, multicentre, Phase 4 study consisted of a 16-week, randomized, double-blind, placebo-controlled phase and a 36-week open label extension phase (NCT02201004). Japanese patients with type 2 diabetes mellitus, aged 20 to 75 years, with suboptimal glycaemic control (7.5%-10.5%) receiving insulin monotherapy (basal-bolus, bolus, premix [low and high] and basal) or receiving combination therapy with basal insulin and dipeptidyl peptidase-4 inhibitor were eligible for participation. Patients who received tofogliflozin throughout the study (52 weeks) were referred to as the 'tofo-tofo group' and patients who received placebo and tofogliflozin (36 weeks) were referred to as the 'pla-tofo group'.

RESULTS

A total of 210 patients received treatment per randomization. Hypoglycaemia was the most common treatment-emergent adverse event (AE) (42.9% in the tofo-tofo group and 29.4% in the pla-tofo group). Patients reported genital infection, urinary tract infection, excessive urination and AEs related to volume depletion (2.1%, 2.1%, 7.1% and 10.0% of patients in the tofo-tofo group, and 0%, 1.5%, 2.9% and 7.4% of patients in the pla-tofo group, respectively). Mean HbA1c and body weight at baseline (mean changes ± standard error from baseline to Week 52) in the tofo-tofo and pla-tofo groups were 8.53% (-0.76% ± 0.077) and 8.40% (-0.73% ± 0.102); 68.84 kg (-1.52 kg ± 0.207) and 72.24 kg (-2.13 kg ± 0.313), respectively.

CONCLUSIONS

This study demonstrates the safety and efficacy of tofogliflozin as add-on to insulin therapy in type 2 diabetes mellitus patients, offering a new therapeutic solution to diabetes management.

Empagliflozin influences blood viscosity and wall shear stress in subjects with type 2 diabetes mellitus compared with incretin-based therapy

Background

Cardiovascular protection following empagliflozin therapy is not entirely attributable to the glucose lowering effect. Increased hematocrit might influence the shear stress that is the main force acting on the endothelium, regulating its anti-atherogenic function.

Objective

We designed the study with the aim of investigating the effect of empagliflozin on blood viscosity and shear stress in the carotid arteries. A secondary endpoint was the effect of empagliflozin on carotid artery wall thickness.

Methods

The study was a non-randomized, open, prospective cohort study including 35 type 2 diabetic outpatients who were offered empagliflozin or incretin-based therapy (7 liraglutide, 8 sitagliptin) in combination with insulin and metformin. Blood viscosity, shear stress and carotid wall thickness were measured at baseline and at 1 and 3 months of treatment. Blood viscosity was measured with a viscometer, and shear stress was calculated using a validated formula. Intima-media thickness (IMT) of the carotid artery was detected by ultrasound and was measured with dedicated software.

Results

Blood viscosity (4.87 ± 0.57 vs 5.32 ± 0.66 cP, p < 0.02) and shear stress significantly increased in the Empagliflozin group while no change was detected in the Control group (4.66 ± 0.56 vs 4.98 ± 0.73 cP, p = NS). IMT significantly decreased in the Empagliflozin group after 1 and 3 months (baseline: 831 ± 156, 1-month 793 ± 150, 3-month 766 ± 127 μm; p < 0.0001), while in the liraglutide group, IMT significantly decreased only after 3 months (baseline 879 ± 120; 1-month 861 ± 163; 3-month 802 ± 114 μm; p < 0.001). In the sitagliptin group, IMT remained almost unchanged (baseline 901 ± 135; 1-month 902 ± 129; 3-month 880 ± 140 μm; p = NS).

Conclusions

This study is the first to describe a direct effect of empagliflozin on blood viscosity and wall shear stress. Furthermore, IMT was markedly reduced early on in the Empagliflozin group.

Effect of Tofogliflozin on Body Composition and Glycemic Control in Japanese Subjects with Type 2 Diabetes Mellitus

Sodium-glucose cotransporter 2 inhibitor tofogliflozin is a new type of antidiabetic drug for individuals with type 2 diabetes mellitus (T2DM). The aim of this study was to examine in which type of individuals and/or under which conditions tofogliflozin could exert more beneficial effects on body composition and/or glycemic control in Japanese individuals with T2DM. We retrospectively evaluated the effects of tofogliflozin on body composition and/or glycemic control in individuals with T2DM who newly started taking tofogliflozin. After tofogliflozin treatment, body weight was significantly reduced and HbA1c levels were significantly decreased. Body fat mass, skeletal muscle mass, and skeletal muscle index, a marker for sarcopenia, were also reduced after the treatment. In univariate analyses, there was a statistically significant association between the decrease of HbA1c level after tofogliflozin treatment (Δ HbA1c) and the following parameters such as HbA1c levels at baseline, visceral fat area (VFA) at baseline, and reduction of VFA after the treatment (Δ VFA). Furthermore, in multivariate analyses, HbA1c levels at baseline and duration of diabetes were independently associated with Δ HbA1c. These results suggest that tofogliflozin would be more suitable for relatively obese individuals whose duration of diabetes is relatively short.

Sodium Glucose Cotransporter-2 Inhibition in Heart Failure: Potential Mechanisms, Clinical Applications, and Summary of Clinical Trials

Despite current established therapy, heart failure (HF) remains a leading cause of hospitalization and mortality worldwide. Novel therapeutic targets are therefore needed to improve the prognosis of patients with HF. The EMPA-REG OUTCOME trial ([Empagliflozin] Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) demonstrated significant reductions in mortality and HF hospitalization risk in patients with type 2 diabetes mellitus (T2D) and cardiovascular disease with the antihyperglycemic agent, empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor. The CANVAS trial (Canagliflozin Cardiovascular Assessment Study) subsequently reported a reduction in 3-point major adverse cardiovascular events and HF hospitalization risk. Although SGLT2 inhibition may have potential application beyond T2D, including HF, the mechanisms responsible for the cardioprotective effects of SGLT2 inhibitors remain incompletely understood. SGLT2 inhibition promotes natriuresis and osmotic diuresis, leading to plasma volume contraction and reduced preload, and decreases in blood pressure, arterial stiffness, and afterload as well, thereby improving subendocardial blood flow in patients with HF. SGLT2 inhibition is also associated with preservation of renal function. Based on data from mechanistic studies and clinical trials, large clinical trials with SGLT2 inhibitors are now investigating the potential use of SGLT2 inhibition in patients who have HF with and without T2D. Accordingly, in this review, we summarize the key pharmacodynamic effects of SGLT2 inhibitors and the clinical evidence that support the rationale for the use of SGLT2 inhibitors in patients with HF who have T2D. Because these favorable effects presumably occur independent of blood glucose lowering, we also explore the potential use of SGLT2 inhibition in patients without T2D with HF or at risk of HF, such as in patients with coronary artery disease or hypertension. Finally, we provide a detailed overview and summary of ongoing cardiovascular outcome trials with SGLT2 inhibitors.

Effects of sodium-glucose cotransporter 2 inhibitors on urinary excretion of intact and total angiotensinogen in patients with type 2 diabetes

We conducted a descriptive case study to examine the effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors on urinary angiotensinogen excretion, which represents the function of the intrarenal renin–angiotensin system, in patients with type 2 diabetes. An SGLT2 inhibitor (canagliflozin 100 mg/day, ipragliflozin 25 mg/day, dapagliflozin 5 mg/day, luseogliflozin 2.5 mg/day or tofogliflozin 20 mg/day) was administered for 1 month (n=9). ELISA kits were used to measure both urinary intact and total angiotensinogen levels. Treatment with SGLT2 inhibitors significantly decreased hemoglobin A1c, body weight, systolic blood pressure and diastolic blood pressure (8.5±1.3 to 7.5%±1.0%, 82.5±20.2 to 80.6±20.9 kg, 143±8 to 128±14 mm Hg, 78±10 to 67±9 mm Hg, p<0.05, respectively), while urinary albumin/creatinine ratio was not significantly changed (58.6±58.9 to 29.2±60.7 mg/g, p=0.16). Both total urinary angiotensinogen/creatinine ratio and intact urinary angiotensinogen/creatinine ratio tended to decrease after administration of SGLT2 inhibitors. However, these changes were not significant (p=0.19 and p=0.08, respectively). These data suggest that treatment with SGLT2 inhibitors does not activate the intrarenal renin–angiotensin system in patients with type 2 diabetes.

Characteristics and Impact Factors of Renal Threshold for Glucose Excretion in Patients with Type 2 Diabetes Mellitus

Sodium glucose co-transporter 2 (SGLT-2) inhibitors are newly developed but promising medicine for type 2 diabetes. However, patients with a different renal threshold for glucose excretion (RT(G)) may have a different reaction to this medicine. Therefore, the objective of this study was to investigate the characteristics of RT(G) and its impact factors in patients with type 2 diabetes mellitus (T2DM). The clinical and laboratory data of 36 healthy individuals and 168 in-hospital patients with T2DM were collected and analyzed, RT(G) was calculated using blood glucose (BG) measured by dynamic BG monitoring, urinary glucose excretion (UGE) and estimated glomerular filtration rate (eGFR). The characteristics of RT(G) were investigated. The risk factors for high RT(G) were analyzed using non-conditional logistic regression analysis. Our results found that RT(G) of the T2DM group was higher than that of the healthy individuals (P < 0.05); and 22.22% from the healthy individuals group but 58.33% from the T2DM group had high RT(G). Age, duration of diabetes, body mass index (BMI), and homeostasis model assessment insulin resistance index (HOMA-IR) were independently associated with high RT(G) (P < 0.05). Further stratified analysis revealed that RT(G) in T2DM patients increased with age, duration of diabetes, and BMI. In conclusion, RT(G) is increased in patients with T2DM, especially in those with longer diabetic duration, higher BMI, and those who are older. Therefore, these patients may be more sensitive to SGLT-2 inhibitors.

Evaluation of metabolic parameters and body composition in Japanese patients with type 2 diabetes mellitus who were administered tofogliflozin for 48 weeks

Sodium glucose cotransporter 2 inhibitors are unique antihyperglycemic agents that cause osmotic diuresis and calorie loss to urine. We previously reported that administration of tofogliflozin, a sodium glucose cotransporter 2 inhibitor, for 8 weeks decreased fat-free mass without affecting fat mass. We thus investigated the impact of tofogliflozin on metabolic parameters and body composition for 48 weeks in Japanese patients with type 2 diabetes mellitus. This single-arm open-label study enrolled 20 patients. Patients received tofogliflozin 20 mg once daily for 48 weeks. At week 48, changes in metabolic parameters and body composition from baseline were evaluated. Two patients discontinued administration due to adverse events during the first 8 weeks; however, no other adverse events occurred after that period. Seventeen patients completed the 48 weeks of administration of tofogliflodin. Body weight and body mass index decreased during the treatment period. Hemoglobin A1c decreased from 7.8% to 7.1%. The degree of improvement in hemoglobin A1c was correlated with body mass index, fat mass, and plasma glucose level at baseline. As for body composition, fat mass decreased without any change in fat-free mass (including total body water, extracellular water, and intracellular water). Red blood cell count and hematocrit increased, while the estimated glomerular filtration rate decreased. ALT and γ-GTP decreased and the decrease in γ-GTP was correlated with the loss of fat mass. In conclusion, our study clearly suggests that the body weight reduction caused by tofogliflozin administration for 48 weeks was almost entirely due to fat mass dissipation.

Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence: A Scientific Statement From the American Heart Association and the American Diabetes Association

Cardiovascular disease risk factor control as primary prevention in patients with type 2 diabetes mellitus has changed substantially in the past few years. The purpose of this scientific statement is to review the current literature and key clinical trials pertaining to blood pressure and blood glucose control, cholesterol management, aspirin therapy, and lifestyle modification. We present a synthesis of the recent literature, new guidelines, and clinical targets, including screening for kidney and subclinical cardiovascular disease for the contemporary management of patients with type 2 diabetes mellitus.

Empagliflozin: a review of its use in patients with type 2 diabetes mellitus

Oral empagliflozin (Jardiance(®)), a sodium glucose cotransporter-2 (SGLT2) inhibitor, is a convenient once-daily treatment for adult patients with type 2 diabetes mellitus. By inhibiting reabsorption of glucose from the proximal tubules in the kidney via inhibition of SGLT2, empagliflozin provides a novel insulin-independent mechanism of lowering blood glucose. In several phase III trials (≤104 weeks' duration; typically 24 weeks' duration) and extension studies (typically ≥76 weeks' treatment), empagliflozin monotherapy or add-on therapy to other antihyperglycaemics, including insulin, improved glycaemic control and reduced bodyweight and systolic blood pressure in adult patients with type 2 diabetes. In a large phase III trial, as add-on therapy to metformin, empagliflozin was shown to be noninferior to glimepiride at 52 and 104 weeks and superior to glimepiride at 104 weeks, in terms of reductions in glycated haemoglobin level (primary endpoint). Empagliflozin was well tolerated by participants in these clinical trials, with most adverse events being mild or moderate in intensity. Empagliflozin treatment appeared to have no intrinsic risk of hypoglycaemia, although hypoglycaemia occurred more frequently when empagliflozin was coadministered with insulin and/or a sulfonylurea. With its insulin-independent mechanism of action, empagliflozin monotherapy or combination therapy with other antidiabetic drugs, including insulin, provides a useful addition to the therapeutic options for the management of type 2 diabetes. This article reviews the pharmacological properties and clinical use of empagliflozin in patients with type 2 diabetes.

Central obesity, type 2 diabetes and insulin: exploring a pathway full of thorns

The prevalence of type 2 diabetes (T2D) is rapidly increasing. This is strongly related to the contemporary lifestyle changes that have resulted in increased rates of overweight individuals and obesity. Central (intra-abdominal) obesity is observed in the majority of patients with T2D. It is associated with insulin resistance, mainly at the level of skeletal muscle, adipose tissue and liver. The discovery of macrophage infiltration in the abdominal adipose tissue and the unbalanced production of adipocyte cytokines (adipokines) was an essential step towards novel research perspectives for a better understanding of the molecular mechanisms governing the development of insulin resistance. Furthermore, in an obese state, the increased cellular uptake of non-esterified fatty acids is exacerbated without any subsequent β-oxidation. This in turn contributes to the accumulation of intermediate lipid metabolites that cause defects in the insulin signaling pathway. This paper examines the possible cellular mechanisms that connect central obesity with defects in the insulin pathway. It discusses the discrepancies observed from studies organized in cell cultures, animal models and humans. Finally, it emphasizes the need for therapeutic strategies in order to achieve weight reduction in overweight and obese patients with T2D.

Ipragliflozin: A novel sodium-glucose cotransporter 2 inhibitor developed in Japan

Sodium-glucose cotransporter 2 (SGLT2) inhibition induces glucosuria and decreases blood glucose levels in diabetic patients and lowers hypoglycemic risk. SGLT1 is expressed in the kidney and intestine; SGLT1 inhibition causes abdominal symptoms such as diarrhea and reduces incretin secretion. Therefore, SGLT2 selectivity is important. Ipragliflozin is highly selective for SGLT2. In type 2 diabetes mellitus (T2DM), urinary glucose excretion increased to 90 g/24 h after 28 d of treatment with ipragliflozin 300 mg/d. Twelve weeks of ipragliflozin 50 mg/d vs placebo reduced glycated hemoglobin and body weight by 0.65% and 0.66 kg, respectively, in Western T2DM patients, and by 1.3% and 1.89 kg, respectively, in Japanese patients. Ipragliflozin (highly selective SGLT2 inhibitor) improves glycemic control and reduces body weight and lowers hypoglycemic risk and abdominal symptoms. Ipragliflozin can be a novel anti-diabetic and anti-obesity agent.

Empagliflozin: a new sodium-glucose co-transporter 2 (SGLT2) inhibitor for the treatment of type 2 diabetes

Type 2 diabetes is increasing in prevalence worldwide, and hyperglycemia is often poorly controlled despite a number of therapeutic options. Unlike previously available agents, sodium-glucose co-transporter 2 (SGLT2) inhibitors offer an insulin-independent mechanism for improving blood glucose levels, since they promote urinary glucose excretion (UGE) by inhibiting glucose reabsorption in the kidney. In addition to glucose control, SGLT2 inhibitors are associated with weight loss and blood pressure reductions, and do not increase the risk of hypoglycemia. Empagliflozin is a selective inhibitor of SGLT2, providing dose-dependent UGE increases in healthy volunteers, with up to 90 g of glucose excreted per day. It can be administered orally, and studies of people with renal or hepatic impairment indicated empagliflozin needed no dose adjustment based on pharmacokinetics. In Phase II trials in patients with type 2 diabetes, empagliflozin provided improvements in glycosylated hemoglobin (HbA1c) and other measures of glycemic control when given as monotherapy or add-on to metformin, as well as reductions in weight and systolic blood pressure. As add-on to basal insulin, empagliflozin not only improved HbA1c levels but also reduced insulin doses. Across studies, empagliflozin was generally well tolerated with a similar rate of hypoglycemia to placebo; however, patients had a slightly increased frequency of genital infections, but not urinary tract infections, versus placebo. Phase III studies have also reported a good safety profile along with significant improvements in HbA1c, weight and blood pressure, with no increased risk of hypoglycemia versus placebo. Based on available data, it appears that empagliflozin may be a useful option in a range of patients; however, clinical decisions will be better informed by the results of ongoing studies, in particular, a large cardiovascular outcome study (EMPA-REG OUTCOME™).

Renal effects of dapagliflozin in patients with type 2 diabetes

Diabetes mellitus was originally conceived as a renal disorder. In the last decade, however, there has been renewed interest in role of the kidney in the development and maintenance of high glucose levels. This has led to the development of novel agents to inhibit sodium glucose transporter-2 (SGLT2) as a means to better control glucose levels and at the same time augment calorie wasting and lower insulin, blood pressure and uric acid levels. Such actions, indirectly, may also have benefits for the prevention of diabetic complications including renal disease. However, there are also data to support the potential for direct renoprotective actions arising from inhibition of SGLT2, including actions to attenuate diabetes-associated hyperfiltration and tubular hypertrophy, as well as reduce the tubular toxicity of glucose. Some studies have demonstrated significant reductions in albumin excretion in various experimental models, independent of its effects on blood pressure or glucose control. Although promising, such actions remain to be established by comprehensive clinical trials with a renal focus, many of which are currently in progress. This article reviews the clinical and experimental data pertaining to the renal effects of SGLT2 inhibition with a particular focus on dapaglifozin.

Renal sodium glucose cotransporter 2 inhibitors as a novel therapeutic approach to treatment of type 2 diabetes: Clinical data and mechanism of action

Type 2 diabetes is characterized by impaired insulin secretion from pancreatic β-cells and/or reduced response of target tissues to insulin. Good glycemic control delays the development and slows the progression of micro- and macrovascular complications. Although there are numerous glucose-lowering agents in clinical use, only approximately half of type 2 diabetic patients achieve glycemic control, and undesirable side-effects often hamper treatment in those treated with the medications. There is a need for novel treatment options that can help overcome these difficulties. Sodium glucose cotransporter 2 (SGLT2) inhibitors have recently been developed as a novel potential therapeutic option for the treatment of type 2 diabetes. These drugs lower the plasma glucose concentration through inhibition of glucose reuptake in the kidney, independent of insulin secretion and insulin action, with a consequent lower risk of hypoglycemia. The data of clinical trials with monotherapy as well as combination therapy show that SGLT2 inhibitors have a blood glucose-lowering effect and also reduce bodyweight. A follow-up study shows long-term efficacy and the durability of these effects. SGLT2 inhibitors have the potential to reverse glucose toxicity, and to improve insulin resistance, blood pressure and lipid profile. The available data suggest a good tolerability profile. However, clinicians should carefully prescribe these drugs in light of already reported and/or unexpected side-effects. Further studies in larger numbers and longer-term clinical use data are required to place these agents in standard treatment of type 2 diabetes.

Novel metabolic drugs and blood pressure: implications for the treatment of obese hypertensive patients?

Hypertension and obesity often coexist, exposing patients to cardiovascular and metabolic risks, particularly type 2 diabetes mellitus. Moreover, obesity may render hypertensive patients treatment resistant. We review how drugs recently approved for obesity or type 2 diabetes mellitus treatment affect blood pressure. The weight-reducing drug lorcaserin induces modest reductions in body weight while slightly improving blood pressure. The fixed low-dose topiramate/phentermine combinations elicit larger reductions in body weight and blood pressure. Concomitant improvements in glucose metabolism, adiposity, and blood pressure differentiate the first clinically available SGLT2 inhibitor dapagliflozin from other oral antidiabetic drugs. Yet, the mechanisms through which metabolic drugs affect blood pressure and their interaction with antihypertensive drugs are poorly understood. Blood pressure-lowering effects of metabolic drugs could be exploited in the clinical management of obese hypertensive patients with and without type 2 diabetes mellitus, particularly in patients with difficult to control arterial hypertension.

Canagliflozin (invokana), a novel oral agent for type-2 diabetes

Canagliflozin (Invokana) for type-2 diabetes

Rationale, design and baseline characteristics of a 4-year (208-week) phase III trial of empagliflozin, an SGLT2 inhibitor, versus glimepiride as add-on to metformin in patients with type 2 diabetes mellitus with insufficient glycemic control

BACKGROUND

Sulfonylureas (SUs) are commonly used in the treatment of type 2 diabetes (T2DM), usually as second-line treatment after the failure of metformin. However, SUs are associated with poor durability, hypoglycemia and weight gain. Empagliflozin is a sodium glucose cotransporter 2 (SGLT2) inhibitor in development for the treatment of T2DM. In Phase II/III trials, empagliflozin reduced hyperglycemia, body weight and blood pressure, with a low incidence of hypoglycemia. The aim of this Phase III study is to compare the effects of empagliflozin and the SU glimepiride as second-line therapy in patients with T2DM inadequately controlled with metformin immediate release (IR) and diet/exercise.

METHOD

After a 2-week placebo run-in, patients were randomized to receive empagliflozin 25 mg once daily (qd) or glimepiride 1-4 mg qd double-blind for 2 years, in addition to metformin IR. Patients who participate in the initial 2-year randomization period will be eligible for a 2-year double-blind extension. The primary endpoint is change from baseline in HbA1c. Secondary endpoints are change from baseline in body weight, the incidence of confirmed hypoglycemia and changes in systolic and diastolic blood pressure. Exploratory endpoints include markers of insulin secretion, body composition and responder analyses. Safety endpoints include the incidence of adverse events (AEs) (including macro- and microvascular adverse events) and changes from baseline in clinical laboratory parameters.

RESULTS

Between August 2010 and June 2011, 1549 patients were randomized and 1545 patients were treated. At baseline, mean (SD) age was 55.9 (10.4) years, HbA1c was 7.92 (0.84)%, body mass index was 30.11 (5.59) kg/m², systolic blood pressure was 133.5 (15.9) mmHg and diastolic blood pressure was 79.5 (9.4) mmHg.

DISCUSSION

This is the largest study to compare the efficacy and safety of an SGLT2 inhibitor with an SU in patients with T2DM inadequately controlled on metformin to date. In addition to determining the effects of these treatments on glycemic control over the long term, this study will investigate effects on beta-cell function, cardiovascular risk factors and markers of renal function/damage. The results will help to inform the choice of second-line treatment in patients with T2DM who have failed on metformin.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01167881.

Endothelial dysfunction in diabetes: pathogenesis, significance, and treatment

Type 2 diabetes (T2D) markedly increases the risk of cardiovascular disease. Endothelial dysfunction (ED), an early indicator of diabetic vascular disease, is common in T2D and independently predicts cardiovascular risk. Although the precise pathogenic mechanisms for ED in T2D remain unclear, at inception they probably involve uncoupling of both endothelial nitric oxide synthase activity and mitochondrial oxidative phosphorylation, as well as the activation of vascular nicotinamide adenine dinucleotide phosphate oxidase. The major contributing factors include dyslipoproteinemia, oxidative stress, and inflammation. Therapeutic interventions are designed to target these pathophysiological factors that underlie ED. Therapeutic interventions, including lifestyle changes, antiglycemic agents and lipid-regulating therapies, aim to correct hyperglycemia and atherogenic dyslipidemia and to improve ED. However, high residual cardiovascular risk is seen in both research and clinical practice settings. Well-designed studies of endothelial function in appropriately selected volunteers afford a good opportunity to test new therapeutic interventions, paving the way for clinical trials and utilization in the care of the diabetic patient. However, based on the results from a recent clinical trial, niacin should not be added to a statin in individuals with low high-density lipoprotein cholesterol and very well controlled low-density lipoprotein cholesterol.