Sotagliflozin as a potential treatment for type 2 diabetes mellitus

Exploring the Efficacy of Sotagliflozin on Heart and Kidney Health in Diabetic Patients: A Comprehensive Meta-Analysis

Evidence for reducing cardiovascular and renal events with sotagliflozin is uncertain among type 2 diabetes mellitus (T2DM) patients. To gather more evidence, this meta-analysis assesses the beneficial effects of sotagliflozin, a dual sodium-glucose cotransporter 1 and 2 inhibitor, in reducing the cardiovascular and renal events in diabetic patients with or without chronic kidney disease (CKD). Scopus, Google Scholar, Cochrane Central Register of Controlled Trials (CENTRAL), and PubMed were the databases used to search. The studies published from January 1, 2018, to January 30, 2022, were considered. The eligibility of studies was assessed independently. The data were collected in a modified Cochrane data extraction form. The included studies' quality was assessed with the Cochrane risk-of-bias tool. The quality of evidence for renal and cardiovascular outcomes was evaluated using GRADEpro software. The number of events of urgent visits to the hospital and requiring hospitalization was reduced (RR: 0.73; 95% CI: 0.69, 0.78; P value <0.00001). The mortality rate because of cardiovascular events was decreased with sotagliflozin (RR: 0.73; 95% CI: 0.67, 0.80; P value <0.00001). Patients taking sotagliflozin had a drastic decline in the number of deaths due to stroke and non-fatal myocardial infarction. Yet, there is no difference between the groups in terms of changes in mortality due to other causes or the glomerular filtration rate (GFR). Sotagliflozin demonstrated effectiveness in reducing the mortality rate related to heart failure and cardiovascular events when the dose was increased from 200 mg to 400 mg. Despite this, evidence is still needed to prove the renal protective action.

SGLT1: A Potential Drug Target for Cardiovascular Disease

SGLT1 and SGLT2 are the two main members of the sodium-glucose cotransporters (SGLTs), which are mainly responsible for glucose reabsorption in the body. In recent years, many large clinical trials have shown that SGLT2 inhibitors have cardiovascular protection for diabetic and non-diabetic patients independent of lowering blood glucose. However, SGLT2 was barely detected in the hearts of humans and animals, while SGLT1 was highly expressed in myocardium. As SGLT2 inhibitors also have a moderate inhibitory effect on SGLT1, the cardiovascular protection of SGLT2 inhibitors may be due to SGLT1 inhibition. SGLT1 expression is associated with pathological processes such as cardiac oxidative stress, inflammation, fibrosis, and cell apoptosis, as well as mitochondrial dysfunction. The purpose of this review is to summarize the protective effects of SGLT1 inhibition on hearts in various cell types, including cardiomyocytes, endothelial cells, and fibroblasts in preclinical studies, and to highlight the underlying molecular mechanisms of protection against cardiovascular diseases. Selective SGLT1 inhibitors could be considered a class of drugs for cardiac-specific therapy in the future.

Metabolic, Intestinal, and Cardiovascular Effects of Sotagliflozin Compared With Empagliflozin in Patients With Type 2 Diabetes: A Randomized, Double-Blind Study

OBJECTIVE

Inhibiting sodium-glucose cotransporters (SGLTs) improves glycemic and cardiovascular outcomes in patients with type 2 diabetes (T2D). We investigated the differential impact of selective SGLT2 inhibition and dual inhibition of SGLT1 and SGLT2 on multiple parameters.

RESEARCH DESIGN AND METHODS

Using a double-blind, parallel-group design, we randomized 40 patients with T2D and hypertension to receive the dual SGLT1 and SGLT2 inhibitor sotagliflozin 400 mg or the selective SGLT2 inhibitor empagliflozin 25 mg, with preexisting antihypertensive treatment, for 8 weeks. In an in-house testing site, mixed-meal tolerance tests (MMTTs) and other laboratory and clinical evaluations were used to study metabolic, intestinal, cardiovascular, and urinary parameters over 24 h.

RESULTS

Changes from baseline in glycemic and blood pressure control; intestinal, urine, and metabolic parameters; and cardiovascular biomarkers were generally similar with sotagliflozin and empagliflozin. During the breakfast MMTT, sotagliflozin significantly reduced incremental area under the curve (AUC) values for postprandial glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) and significantly increased incremental AUCs for postprandial glucagon-like peptide 1 (GLP-1) relative to empagliflozin, consistent with sotagliflozin-mediated inhibition of intestinal SGLT1. These changes waned during lunch and dinner MMTTs. Both treatments significantly lowered GIP incremental AUCs relative to baseline over the 14 h MMTT interval; the most vigorous effect was seen with sotagliflozin soon after start of the first meal of the day. No serious or severe adverse events were observed.

CONCLUSIONS

Changes from baseline in glycemic and blood pressure control, cardiovascular biomarkers, and other parameters were comparable between sotagliflozin and empagliflozin. However, sotagliflozin but not empagliflozin inhibited intestinal SGLT1 after breakfast as shown by larger changes in postprandial glucose, insulin, GIP, and GLP-1 AUCs, particularly after breakfast. Additional study is warranted to assess the clinical relevance of transient SGLT1 inhibition and differences in incretin responses (NCT03462069).

Turning Foes to Friends: Knocking Down Diabetes Associated SGLT2 Transporters and Sustaining Life

BACKGROUND

The discovery of Sodium-Glucose co-transporter-2 (SGLT2) inhibitors had rewritten the treatment of diabetes mellitus with an impressive fall in the incidence of death and associated complications.

INTRODUCTION

The SGLT2 inhibitors by inhibiting the SGLT2 in the proximal nephron, helps in reducing the reabsorption of approximately 90% of the filtered glucose and increased urinary glucose excretion (UGE).

METHODS

The literature related to SGLT2 inhibitors has been thoroughly explored from various available public domains and reviewed extensively for this article. Detailed and updated information related to SGLT2 inhibitors with a major focus on the recently approved Ertuglifolzin is structured in this review.

RESULT

The present review is an effort to understand the management of diabetes mellitus over the past few decades with a special focus on the role of SGLT2 receptor in the causes of therapeutic and preventive strategies for diabetes mellitus. Pragmatic placement of the currently available Canagliflozin, Dapagliflozin, and Empagliflozin as oral antidiabetic agents has been done. Well accommodated stereochemistry and a high docking score of Ertugliflozin in ligand-receptor simulation studies attribute to its high potency.

CONCLUSION

This review highlights the unique mechanism of SGLT2 Inhibitors coupled with pleiotropic benefits on weight and blood pressure, which make it an attractive choice of therapy to diabetic patients, not controlled by other medications.

Sugar-Lowering Drugs for Type 2 Diabetes Mellitus and Metabolic Syndrome-Review of Classical and New Compounds: Part-I

Diabetes mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia together with disturbances in the metabolism of carbohydrates, proteins and fat, which in general results from an insulin availability and need imbalance. In a great number of patients, marketed anti-glycemic agents have shown poor effectiveness in maintaining a long-term glycemic control, thus being associated with severe adverse effects and leading to an emerging interest in natural compounds (e.g., essential oils and other secondary plant metabolites, namely, flavonoid-rich compounds) as a novel approach for prevention, management and/or treatment of either non-insulin-dependent diabetes mellitus (T2DM, type 2 DM) and/or Metabolic Syndrome (MS). In this review, some of these promising glucose-lowering agents will be comprehensively discussed.

An update of SGLT1 and SGLT2 inhibitors in early phase diabetes-type 2 clinical trials

Introduction: More than 424 million adults have diabetes mellitus (DM). This number is expected to increase to 626 million by 2045. The majority (90-95%) of people with DM has type 2-diabetes (T2DM). The continued prevalence of DM and associated complications has prompted investigators to find new therapies. One of the most recent additions to the anti-diabetic armamentarium are inhibitors of sodium-glucose co-transporters 1 and 2 (SGLT1, SGLT2). Areas covered: The authors review the status of SGLT2 inhibitors for the treatment of T2DM and place an emphasis on those agents in early phase clinical trials. Data and information were retrieved from American Diabetes Association, Diabetes UK, ClinicalTrials.gov, PubMed, and Scopus websites. The keywords used in the search were T2DM, SGLT1, SGLT2, and clinical trials. Expert opinion: The benefits of SGLT inhibitors include reductions in serum glycated hemoglobin (HbA1c), body weight, blood pressure and cardiovascular and renal events. However, SGLT inhibitors increase the risk of genitourinary tract infections, diabetic ketoacidosis, and bone fractures. The development of SGLT inhibitors with fewer side effects and as combination therapies are the key to maximizing the therapeutic effects of this important class of anti-diabetic drug.

Cardiovascular outcome studies in type 2 diabetes: Comparison between SGLT2 inhibitors and GLP-1 receptor agonists

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) are two pharmacological classes that have proven their efficacy to reduce major cardiovascular events (MACEs) in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease in large prospective cardiovascular outcome trials (CVOTs): EMPA-REG OUTCOME (empagliflozin), CANVAS (canagliflozin), LEADER (liraglutide) and SUSTAIN 6 (semaglutide). Some heterogeneity appears to exist between the various agents within the two pharmacological classes. Whether these positive results could be extrapolated to patients without cardiovascular disease is still unknown. The underlying mechanisms remain a matter of debate but appear to differ between SGLT2is and GLP-1RAs. One crucial question is which patient's characteristics should be taken into account to guide the choice between a SGLT2i or a GLP-1RA according to a personalized approach. Heart failure should encourage the use of a SGLT2i whereas moderate to severe chronic kidney disease should favour the prescription of a GLP-1RA. Despite the results of recent CVOTs, numerous patients who are good candidates for benefiting of these agents do not receive them in clinical practice. Currently, there is a paradigm shift in T2DM management, moving from a primary objective of glucose control to a cardiovascular and renal protection.

HbA1c and Hypoglycemia Reductions at 24 and 52 Weeks With Sotagliflozin in Combination With Insulin in Adults With Type 1 Diabetes: The European inTandem2 Study

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of the dual sodium-glucose cotransporter 1 and 2 inhibitor sotagliflozin compared with placebo when combined with optimized insulin in adults with type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

In a double-blind, 52-week, international phase 3 trial, adults with T1D were randomized to placebo (n = 258) or once-daily oral sotagliflozin 200 mg (n = 261) or 400 mg (n = 263) after 6 weeks of insulin optimization. The primary outcome was change in HbA_1c from baseline to 24 weeks. The first secondary end point was a composite of the proportion of patients with HbA_1c <7.0%, no episode of severe hypoglycemia, and no episode of diabetic ketoacidosis (DKA) at week 24. Fasting glucose, weight, insulin dose, and safety end points were assessed through 52 weeks.

RESULTS

At 24 weeks, placebo-adjusted changes in HbA_1c from baseline (7.8%) were -0.37% and -0.35% with sotagliflozin 200 and 400 mg, respectively (P < 0.001), and differences were maintained at 52 weeks. At 52 weeks, greater proportions of sotagliflozin-treated patients (200 mg: 25.67%; 400 mg: 26.62%) than placebo-treated patients (14.34%; P ≤ 0.001) met the composite end point, and sotagliflozin 400 mg reduced fasting plasma glucose (-0.87 mmol/L; P = 0.008), weight (-2.92 kg; P < 0.001), and total daily insulin dose (-8.2%; P = 0.001). In a 24-week continuous glucose monitoring (CGM) substudy, postprandial glucose decreased (P ≤ 0.009) and CGM demonstrated up to 3 h more time in the target range of 3.9-10.0 mmol/L with sotagliflozin. Treatment satisfaction increased and diabetes distress decreased with sotagliflozin (P < 0.05 vs. placebo). The frequency of documented hypoglycemia was lower with sotagliflozin, and severe hypoglycemia occurred by week 52 in 13 patients (5.0%), 13 patients (5.0%), and 6 patients (2.3%) treated with placebo and sotagliflozin 200 and 400 mg, respectively. DKA occurred in 0 of 258 patients, 6 of 261 patients (2.3%), and 9 of 263 patients (3.4%) in these respective groups.

CONCLUSIONS

In a 1-year study, sotagliflozin was associated with statistically significant HbA_1c reductions. More episodes of DKA and fewer episodes of documented and severe hypoglycemia were observed in patients using sotagliflozin relative to those receiving placebo (ClinicalTrials.gov, NCT02421510).

Non-insulin pharmacological therapies for treating type 1 diabetes

INTRODUCTION

Despite intensified insulin treatment, many persons with type 1 diabetes (T1D) do not achieve glycemic and metabolic targets. Consequently, non-insulin chemical therapies that improve glycemic control and metabolic parameters without increasing the risk of adverse events (including hypoglycemia) are of interest as adjunct therapies to insulin.

AREAS COVERED

In this review, the authors discuss the efficacy and safety of non-insulin therapies, including pramlintide, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 inhibitors (DPP-4), sodium-glucose cotransporter (SGLT1 and SGLT2) inhibitors, metformin, sulfonylureas, and thiazolidinediones as add-on therapies to insulin in T1D.

EXPERT OPINION

The current evidence shows that the efficacy of non-insulin therapies as add-on therapies to insulin is minimal or modest with an average HbA1c reduction of 0.2-0.5% (2-6 mmol/mol). Indeed, the current focus is on the development of SGLT inhibitors as adjuncts to insulin in type 1 diabetes. Studies of subgroups with obesity, residual beta-cell function (including newly diagnosed patients) and patients prone to hypoglycemia could be areas of future research.

Sotagliflozin: a dual sodium-glucose co-transporter-1 and -2 inhibitor for the management of Type 1 and Type 2 diabetes mellitus

AIMS

To evaluate the evidence for the novel dual sodium-glucose co-transporter-1 (SGLT1) and -2 (SGLT2) inhibitor, sotagliflozin, which may enhance the efficacy of SGLT2 inhibitors by additionally reducing intestinal glucose absorption.

METHODS

The search terms 'sotagliflozin', 'LX4211', 'SGLT' and 'diabetes' were entered into PubMed. Evidence for the pharmacokinetics, pharmacodynamics, safety and efficacy of sotagliflozin in Type 1 and 2 diabetes was extracted from the retrieved literature, critically evaluated, and contextualized in relation to data on existing SGLT2 inhibitors.

RESULTS

There is convincing evidence from a range of phase II and III clinical trials that sotagliflozin significantly improves glycaemic control in both Type 1 and Type 2 diabetes. Additional benefits, such as smaller postprandial plasma glucose excursions, lower insulin requirements, appetite suppression and weight loss have been documented. While this is encouraging, several safety concerns remain; a dose-dependent increase in the rate of diabetic ketoacidosis, diarrhoea and genital mycotic infection is apparent, although statistical exploration of the data regarding such events is currently lacking. Speculatively, use of a 200-mg rather than a 400-mg dose may help to limit unwanted effects.

CONCLUSIONS

The current evidence for sotagliflozin in diabetes appears promising. Further studies sufficiently powered to assess present and emerging safety concerns, as well as to identify individuals for whom sotagliflozin may be of particular benefit/harm would now be informative for regulatory decision-making. Direct comparisons with existing SGLT2 inhibitors are also needed to determine relative safety/efficacy profiles for the different indications.

Understanding the impact of commonly utilized, non-insulin, glucose-lowering drugs on body weight in patients with type 2 diabetes

INTRODUCTION

The majority of patients with type 2 diabetes also have obesity. Obesity increases the risk of developing diabetes and is associated with worsened glycemic control and increased morbidity and mortality in individuals with diabetes. Sustained weight loss is associated with improved glycemic control, potential for diabetes remission, and decreased medical expenditures.

AREAS COVERED

Herein, the impact of commonly utilized, non-insulin, glucose-lowering drugs on body weight in patients with type 2 diabetes is discussed. The weight change magnitudes, mechanisms, and any within-class differences are also explored.

EXPERT OPINION

The weight impact of diabetes medications should be considered when designing treatment regimens, especially in patients who are overweight or have obesity. Lifestyle modification is paramount for optimal diabetes management. Therapeutic regimens should ideally be designed to maximize weight loss and at least minimize or avoid weight gain. Future glucose-lowering medications should continue to offer improvement in cardiovascular risk factors, including weight, in order to be accepted into the armamentarium of diabetes therapy. Therapeutic regimens should be designed to help patients with diabetes and obesity achieve both glycemic and weight goals. Management of these disease states is expected to become increasingly integrated.

Combined SGLT1 and SGLT2 Inhibitors and Their Role in Diabetes Care

The sodium-glucose cotransporter type 1 (SGLT1) is the primary transporter for absorption of glucose and galactose in the gastrointestinal tract. Inhibition blunts and delays postprandial glucose (PPG) excursion. Sodium-glucose cotransporter type 2 (SGLT2) is expressed in the kidney, where it reabsorbs 90% of filtered glucose. Thus, a dual SGLT1 and SGLT2 inhibition (compared with selective SGLT2 inhibition) could result in lower PPG and robust A1c reduction even in patients with reduced kidney function. Sotagliflozin is an oral potent dual inhibitor of the insulin-independent SGLT1 and SGLT2. Preliminary data released from phase 2 and 3 clinical studies in adults with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) showed improved glycemic control, and met efficacy endpoints beyond A1c with a safety profile consistent with the SGLT class: significant reduction in body weight, systolic blood pressure, and efficacy maintained in lower estimated glomerular filtration rate levels with no increased hypoglycemia. Increased risk of diabetic ketoacidosis (DKA) with uncharacteristically mild-to-moderate glucose elevations (euglycemic DKA) is associated with the use of all the approved SGLT2 inhibitors. Factors that trigger DKA include insulin reductions, low caloric and fluid intake, intercurrent illness, and alcohol use. However, DKA is detectable and manageable with proper patient education. With sotagliflozin, DKA rates were not higher than the expected background rate in T1DM, but numerically higher than placebo. Sotagliflozin is the first oral SGLT1 and SGLT2 inhibitor developed for the treatment of adult patients with T1DM, in adjunct with insulin, and has the potential to address unmet needs for patients with T1DM and possibly T2DM, with a favorable benefit/risk profile.

Metformin Alters Upper Small Intestinal Microbiota that Impact a Glucose-SGLT1-Sensing Glucoregulatory Pathway

The gut microbiota alters energy homeostasis. In parallel, metformin regulates upper small intestinal sodium glucose cotransporter-1 (SGLT1), but whether changes of the microbiota or SGLT1-dependent pathways in the upper small intestine mediate metformin action is unknown. Here we report that upper small intestinal glucose sensing triggers an SGLT1-dependent pathway to lower glucose production in rodents. High-fat diet (HFD) feeding reduces glucose sensing and SGLT1 expression in the upper small intestine. Upper small intestinal metformin treatment restores SGLT1 expression and glucose sensing while shifting the upper small intestinal microbiota partly by increasing the abundance of Lactobacillus. Transplantation of upper small intestinal microbiota from metformin-treated HFD rats to the upper small intestine of untreated HFD rats also increases the upper small intestinal abundance of Lactobacillus and glucose sensing via an upregulation of SGLT1 expression. Thus, we demonstrate that metformin alters upper small intestinal microbiota and impacts a glucose-SGLT1-sensing glucoregulatory pathway.

Gut Mechanisms Linking Intestinal Sweet Sensing to Glycemic Control

Sensing nutrients within the gastrointestinal tract engages the enteroendocrine cell system to signal within the mucosa, to intrinsic and extrinsic nerve pathways, and the circulation. This signaling provides powerful feedback from the intestine to slow the rate of gastric emptying, limit postprandial glycemic excursions, and induce satiation. This review focuses on the intestinal sensing of sweet stimuli (including low-calorie sweeteners), which engage similar G-protein-coupled receptors (GPCRs) to the sweet taste receptors (STRs) of the tongue. It explores the enteroendocrine cell signals deployed upon STR activation that act within and outside the gastrointestinal tract, with a focus on the role of this distinctive pathway in regulating glucose transport function via absorptive enterocytes, and the associated impact on postprandial glycemic responses in animals and humans. The emerging role of diet, including low-calorie sweeteners, in modulating the composition of the gut microbiome and how this may impact glycemic responses of the host, is also discussed, as is recent evidence of a causal role of diet-induced dysbiosis in influencing the gut-brain axis to alter gastric emptying and insulin release. Full knowledge of intestinal STR signaling in humans, and its capacity to engage host and/or microbiome mechanisms that modify glycemic control, holds the potential for improved prevention and management of type 2 diabetes.

Cardiovascular effects of sodium glucose cotransporter 2 inhibitors

As the first cardiovascular (CV) outcome trial of a glucose-lowering agent to demonstrate a reduction in the risk of CV events in patients with type 2 diabetes mellitus (T2DM), the EMPAgliflozin Removal of Excess Glucose: Cardiovascular OUTCOME Event Trial in Type 2 Diabetes Mellitus Patients (EMPA-REG OUTCOME^®) trial, which investigated the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin, has generated great interest among health care professionals. CV outcomes data for another SGLT2 inhibitor, canagliflozin, have been published recently in the CANagliflozin CardioVascular Assessment Study (CANVAS) Program, as have CV data from the retrospective real-world study Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors (CVD-REAL), which compared SGLT2 inhibitors with other classes of glucose-lowering drugs. This review discusses the results of these three studies and, with a focus on EMPA-REG OUTCOME, examines the possible mechanisms by which SGLT2 inhibitors may reduce CV risk in patients with T2DM.

Effect of Sodium Glucose Cotransporter 2 Inhibitors With Low SGLT2/SGLT1 Selectivity on Circulating Glucagon-Like Peptide 1 Levels in Type 2 Diabetes Mellitus

Sodium glucose cotransporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs that improve glycemic control by inhibiting reabsorption of glucose filtered through the renal glomerulus. Use of drugs in this class has increased because of their effect of decreasing body weight and a low risk for hypoglycemia, in addition to a relatively strong glucose-lowering effect. SGLT2 inhibitors such as canagliflozin and sotagliflozin (a SGLT1/SGLT2 dual inhibitor) also have a mild or moderate intestinal and renal SGLT1 inhibitory effect because of their relatively weak selectivity for SGLT2 over SGLT1. Recent evidence shows that these SGLT2 inhibitors with low SGLT2/SGLT1 selectivity elevate the level of circulating glucagon like peptide-1 (GLP-1), an incretin hormone that promotes insulin secretion in pancreatic β cells. This effect probably occurs partly via inhibition of intestinal SGLT1, and the elevation of active GLP-1 levels is especially apparent when these drugs are co-administered with dipeptidyl peptidase 4 (DPP4) inhibitors. These findings suggest that a combination of canagliflozin or sotagliflozin and a DPP4 inhibitor can provide a beneficial effect associated with elevation of circulating active GLP-1 and may serve as a treatment for patients with type 2 diabetes.

C-Glycopyranosyl Arenes and Hetarenes: Synthetic Methods and Bioactivity Focused on Antidiabetic Potential

This Review summarizes close to 500 primary publications and surveys published since 2000 about the syntheses and diverse bioactivities of C-glycopyranosyl (het)arenes. A classification of the preparative routes to these synthetic targets according to methodologies and compound categories is provided. Several of these compounds, regardless of their natural or synthetic origin, display antidiabetic properties due to enzyme inhibition (glycogen phosphorylase, protein tyrosine phosphatase 1B) or by inhibiting renal sodium-dependent glucose cotransporter 2 (SGLT2). The latter class of synthetic inhibitors, very recently approved as antihyperglycemic drugs, opens new perspectives in the pharmacological treatment of type 2 diabetes. Various compounds with the C-glycopyranosyl (het)arene motif were subjected to biological studies displaying among others antioxidant, antiviral, antibiotic, antiadhesive, cytotoxic, and glycoenzyme inhibitory effects.

Exome-chip association analysis reveals an Asian-specific missense variant in PAX4 associated with type 2 diabetes in Chinese individuals

AIMS/HYPOTHESIS

Genome-wide association studies (GWASs) have identified many common type 2 diabetes-associated variants, mostly at the intronic or intergenic regions. Recent advancements of exome-array genotyping platforms have opened up a novel means for detecting the associations of low-frequency or rare coding variants with type 2 diabetes. We conducted an exomechip association analysis to identify additional type 2 diabetes susceptibility variants in the Chinese population.

METHODS

An exome-chip association study was conducted by genotyping 5640 Chinese individuals from Hong Kong, using a custom designed exome array, the Asian Exomechip. Single variant association analysis was conducted on 77,468 single nucleotide polymorphisms (SNPs). Fifteen SNPs were subsequently genotyped for replication analysis in an independent Chinese cohort comprising 12,362 individuals from Guangzhou. A combined analysis involving 7189 cases and 10,813 controls was performed.

RESULTS

In the discovery stage, an Asian-specific coding variant rs2233580 (p.Arg192His) in PAX4, and two variants at the known loci, CDKN2B-AS1 and KCNQ1, were significantly associated with type 2 diabetes with exome-wide significance (p _discovery < 6.45 × 10^-7). The risk allele (T) of PAX4 rs2233580 was associated with a younger age at diabetes diagnosis. This variant was replicated in an independent cohort and demonstrated a stronger association that reached genome-wide significance (p _{meta-analysis} [p _meta] = 3.74 × 10^-15) in the combined analysis.

CONCLUSIONS/INTERPRETATION

We identified the association of a PAX4 Asian-specific missense variant rs2233580 with type 2 diabetes in an exome-chip association analysis, supporting the involvement of PAX4 in the pathogenesis of type 2 diabetes. Our findings suggest PAX4 is a possible effector gene of the 7q32 locus, previously identified from GWAS in Asians.

Renal, metabolic and cardiovascular considerations of SGLT2 inhibition

The kidney has a pivotal role in maintaining glucose homeostasis by using glucose as a metabolic fuel, by producing glucose through gluconeogenesis, and by reabsorbing all filtered glucose through the sodium-glucose cotransporters SGLT1 and SGLT2 located in the proximal tubule. In patients with diabetes, the maximum glucose reabsorptive capacity (Tm_G) of the kidney, as well as the threshold for glucose spillage into the urine, are elevated, contributing to the pathogenesis of hyperglycaemia. By reducing the Tm_G and, more importantly, the threshold of glucosuria, SGLT2 inhibitors enhance glucose excretion, leading to a reduction in fasting and postprandial plasma glucose levels and improvements in both insulin secretion and insulin sensitivity. The beneficial effects of SGLT2 inhibition extend beyond glycaemic control, however, with new studies demonstrating that inhibition of renal glucose reabsorption reduces blood pressure, ameliorates glucotoxicity and induces haemodynamic effects that lead to improved cardiovascular and renal outcomes in patients with type 2 diabetes mellitus. In this Review we examine the role of SGLT2 and SGLT1 in the regulation of renal glucose reabsorption in health and disease and the effect of SGLT2 inhibition on renal function, glucose homeostasis, and cardiovascular disease.

Evaluation of the pharmacokinetics, pharmacodynamics and clinical efficacy of empagliflozin for the treatment of type 2 diabetes

INTRODUCTION

Sodium-glucose co-transporter 2 (SGLT2) inhibitors are the latest class of drugs to be introduced for the treatment of type 2 diabetes mellitus. These drugs improve glycemic control by increasing urinary glucose excretion and exert additional benefits of weight loss and blood pressure reductions. Areas covered: This review outlines the background to SGLT2 inhibitors and provides details on the pharmacokinetics, pharmacodynamics and clinical efficacy of empagliflozin and discusses the cardiovascular outcome trial. Expert opinion: Empagliflozin was the first from a new group of antidiabetic drugs to show benefits in a cardiovascular outcome trial. There were significant reductions in cardiovascular and all-cause mortality and empagliflozin treatment reduced hospitalizations for heart failure and reduced the progression of diabetic nephropathy. These benefits, which occurred at a very early stage during the study, may be related to a reduction in circulating volume or changes in metabolic fuel utilization in the heart and kidneys. Whether these effects are shared by other SGLT2 inhibitors is not yet known, but there may be differences between drugs related to selectivity for inhibition of SGLT2 compared to SGLT1 or other pharmacological effects. Currently the outcome evidence is only available to support the use of empagliflozin in this drug class.

Non-insulin drugs to treat hyperglycaemia in type 1 diabetes mellitus

Insulin treatment of individuals with type 1 diabetes has shortcomings and many patients do not achieve glycaemic and metabolic targets. Consequently, the focus is on novel non-insulin therapeutic approaches that reduce hyperglycaemia and improve metabolic variables without increasing the risk of hypoglycaemia or other adverse events. Several therapies given in conjunction with insulin have been investigated in clinical trials, including pramlintide, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sodium-glucose co-transporter inhibitors, metformin, sulfonylureas, and thiazolidinediones. These drugs have pleiotropic effects on glucose metabolism and different actions complementary to those of insulin-this Review reports the effects of these drugs on glycaemic control, glucose variability, hypoglycaemia, insulin requirements, and bodyweight. Existing studies are of short duration with few participants; evidence for the efficacy of concomitant treatments is scarce and largely clinically insignificant. A subgroup of patients with type 1 diabetes for whom non-insulin antidiabetic drugs could significantly benefit glycaemic control cannot yet be defined, but we suggest that obese patients prone to hypoglycaemia and patients with residual β-cell function are populations of interest for future trials.