Emerging sodium/glucose co-transporter 2 inhibitors for type 2 diabetes

Luseogliflozin Additively Enhances the Glucose-Lowering Effect of an Incretin Modulator in a High-Carbohydrate Diet

Background and objectives

Sodium/glucose co-transporter 2 inhibitors (SGLT2i) have been shown to have a glucose-lowering effect related to carbohydrate intake. It has also been reported that the combined effect of incretin modulators and SGLT2i is useful in improving blood glucose and reducing blood glucose variability. However, there have been no reports examining the effects of these two drugs together and while considering carbohydrate intake in an outpatient setting. In the present study, Hi-Speed Food Analysis was used to assess the exact intake of carbohydrates, and the glucose-lowering effects of luseogliflozin, an SGLT2i, and incretin modulators were examined under high- and low-carbohydrate intakes.

Methods

Thirty-five enrolled diabetic patients continued their regular medications for one week. All patients took luseogliflozin in the second week for seven days. During the two weeks, ingested carbohydrates were accurately calculated by Hi-Speed Food Analysis. The glucose-lowering effect of luseogliflozin with and without incretin modulators was checked according to the amount of ingested carbohydrates. A general linear model (GLM) was used to analyze the effect of luseogliflozin with or without an incretin modulator, with carbohydrate intake as a confounding factor.

Results

Luseogliflozin had an additive effect in patients who had taken the incretin modulator. There was a significant decrease in the time above range (TAR) with glucose above 140 mg/dL as expressed as TAR(min140), and this effect was affected by carbohydrate intake.

Conclusions

The glucose-lowering effect of luseogliflozin was enhanced with high-carbohydrate intake more than with low-carbohydrate intake. In this study, the observed number was small; however, combined treatment with an incretin modulator and luseogliflozin had an additive effect in high- versus low-carbohydrate intake, indicating the possible effectiveness of the combined therapy.

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.

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.

Advances in managing type 2 diabetes: challenging old paradigms and developing new ones

As is well known, diabetes rates continue to escalate worldwide, adding cost and disease burden to all health-care institutions. Over the last few years, however, a number of diabetes paradigms have been challenged, not least on the best methods to lessen or delay the development of co-morbidities, in particular cardiovascular disease (CVD) (i.e. targeting blood pressure, cholesterol, and smoking will do more than intensive glucose control). In addition, recent research has offered some hope to potentially reverse diabetes in motivated individuals, with resultant larger and longer trials of such interventions about to commence. This brief review summarizes these important recent developments and suggests that, while many new drugs are being added to the diabetes therapeutic armory, more could and should be done to target sustainable weight change in our patients for multiple health benefits.

Urinary tract infection in diabetes: epidemiologic considerations

The epidemiology of urnary tract infections (UTIs) among men and women with diabetes is similar to the epidemiology of those without: Women have greater risk than men, and frequency of sexual activity is a risk factor. The bacteriology and antibiotic susceptibility patterns also do not, in general, differ from those without diabetes. Although persons with diabetes are more likely to have asymptomatic bacteriuria, asymptomatic bacteriuria does not lead to increased risk of symptomatic infection, except during pregnancy or prior to genital-urinary or gastrointestinal surgery, and should not be treated otherwise. However, diabetes doubles the risk of UTI. The source of this increase is not well understood, although bladder dysfunction, which increases with duration of diabetes, and glycosuria are hypothesized mechanisms. As treatment using sodium glucose cotransporter 2 inhibitors-which lead to glycosuria-increases, there is a potential for the frequency of UTI to increase among those with diabetes.

Sodium-glucose transporter 2 inhibitors in type 2 diabetes mellitus: navigating between Scylla and Charybdis

Despite the extensive pharmacopeia for type 2 diabetes mellitus treatment, long-term glycemic control is far from being optimal, and morbimortality has increased. This demonstrates the importance of developing drugs with new mechanisms of actions, such as sodium-glucose transporter (SGLT) inhibitors (Charybdis). Since the beginning of 2000, numerous SGLT2-inhibitors have been developed and have started to be tested (Scylla) by the pharmaceutical companies that are engaged in this race. Although reductions in hemoglobin A1c have been shown in clinical trials, several issues related to the use of SGLT2 inhibitors deserve further investigation, rendering some aspects of their true safety still uncertain.