Pharmacokinetics, Pharmacodynamics, and Safety of Canagliflozin in Japanese Patients with Type 2 Diabetes Mellitus

The antidiabetic SGLT2 inhibitor canagliflozin reduces mitochondrial metabolism in a model of skeletal muscle insulin resistance

AIMS

Sodium-glucose cotransporter 2 (SGLT2) inhibitors such as canagliflozin (CANA) have emerged as an effective adjuvant therapy in the management of diabetes, however, past observations suggest CANA may alter skeletal muscle mass and function. The purpose of this work was to investigate the effects of CANA on skeletal muscle metabolism both with and without insulin resistance.

METHODS

C2C12 myotubes were treated with CANA with or without insulin resistance. Western blot and qRT-PCR were used to assess protein and gene expression, respectively. Cell metabolism was assessed via oxygen consumption and extracellular acidification rate. Mitochondrial, nuclei and lipid content were measured using fluorescent staining and microscopy.

RESULTS

CANA decreased mitochondrial function and glycolytic metabolism as did insulin resistance, however, these changes occurred without significant alterations in gene expression associated with each pathway. Additionally, while insulin resistance reduced insulin-stimulated pAkt expression, CANA had no significant effect on insulin sensitivity.

CONCLUSIONS

CANA appears to reduce mitochondrial and glycolytic metabolism without altering gene expression governing these pathways, suggesting a reduction in substrate may be responsible for lower metabolism.

Fluid homeostatic action of dapagliflozin in patients with chronic kidney disease: the DAPA-BODY Trial

Sodium glucose cotransporter 2 (SGLT2) inhibitors have both glucose-lowering and diuretic effects. We recently reported that the SGLT2 inhibitor dapagliflozin exerts short-term fluid homeostatic action in patients with chronic kidney disease (CKD). However, the long-term effects of SGLT2 inhibitors on body fluid status in patients with CKD remain unclear. This was a prospective, non-randomized, open-label study that included a dapagliflozin treatment group (n = 73) and a control group (n = 24) who were followed for 6 months. Body fluid volume was measured using a bioimpedance analysis device. The extracellular water-to-total body water ratio (ECW/TBW), a predictor of renal outcomes, was used as a parameter for body fluid status (fluid retention, 0.400 ≤ ECW/TBW). Six-month treatment with dapagliflozin significantly decreased ECW/TBW compared with the control group (-0.65% ± 2.03% vs. 0.97% ± 2.49%, p = 0.0018). Furthermore, dapagliflozin decreased the ECW/TBW in patients with baseline fluid retention, but not in patients without baseline fluid retention (-1.47% ± 1.93% vs. -0.01% ± 1.88%, p = 0.0017). Vasopressin surrogate marker copeptin levels were similar between the control and dapagliflozin groups at 6 months (32.3 ± 33.4 vs. 30.6 ± 30.1 pmol/L, p = 0.8227). However, dapagliflozin significantly increased the change in copeptin levels at 1 week (39.0% ± 41.6%, p = 0.0010), suggesting a compensatory increase in vasopressin secretion to prevent hypovolemia. Renin and aldosterone levels were similar between the control and dapagliflozin groups at 6 months, while epinephrine and norepinephrine (markers of sympathetic nervous system activity) were significantly lower in the dapagliflozin group than in the control group. In conclusion, the SGLT2 inhibitor dapagliflozin ameliorated fluid retention and maintained euvolemic fluid status in patients with CKD, suggesting that SGLT2 inhibitors exert sustained fluid homeostatic actions in patients with various fluid backgrounds. Clinical trial registration: https://www.umin.ac.jp/ctr/, identifier [UMIN000048568].

Comparative safety of different recommended doses of sodium-glucose cotransporter 2 inhibitors in patients with type 2 diabetes mellitus: a systematic review and network meta-analysis of randomized clinical trials

Objective

The safety results of different recommended doses of sodium-glucose cotransporter 2 inhibitors (SGLT-2i) for patients with type 2 diabetes mellitus (T2DM) remain uncertain. This study aims to comprehensively estimate and rank the relative safety outcomes with different doses of SGLT-2i for T2DM.

Methods

PubMed, Embase, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Chinese National Knowledge Infrastructure, WanFang database, and SinoMed database were searched from the inception to 31 May 2023. We included double-blind randomized controlled trials (RCTs) comparing SGLT-2i with placebo or another antihyperglycemic as oral monotherapy in the adults with a diagnosis of T2DM.

Results

Twenty-five RCTs with 12,990 patients randomly assigned to 10 pharmacological interventions and placebo were included. Regarding genital infections (GI), all SGLT-2i, except for ertugliflozin and ipragliflozin, were associated with a higher risk of GI compared to placebo. Empagliflozin 10mg/d (88.2%, odds ratio [OR] 7.90, 95% credible interval [CrI] 3.39 to 22.08) may be the riskiest, followed by empagliflozin 25mg/d (83.4%, OR 7.22, 95%CrI 3.11 to 20.04)) and canagliflozin 300mg/d (70.8%, OR 5.33, 95%CrI 2.25 to 13.83) based on probability rankings. Additionally, dapagliflozin 10mg/d ranked highest for urinary tract infections (UTI, OR 2.11, 95%CrI 1.20 to 3.79, 87.2%), renal impairment (80.7%), and nasopharyngitis (81.6%) when compared to placebo and other treatments. No increased risk of harm was observed with different doses of SGLT-2i regarding hypoglycemia, acute kidney injury, diabetic ketoacidosis, or fracture. Further subgroup analysis by gender revealed no significantly increased risk of UTI. Dapagliflozin 10mg/d (91.9%) and canagliflozin 300mg/d (88.8%) ranked first in the female and male subgroups, respectively, according to the probability rankings for GI.

Conclusion

Current evidence indicated that SGLT-2i did not significantly increase the risk of harm when comparing different doses, except for dapagliflozin 10mg/d, which showed an increased risk of UTI and may be associated with a higher risk of renal impairment and nasopharyngitis. Additionally, compared with placebo and metformin, the risk of GI was notably elevated for empagliflozin 10mg/d, canagliflozin 300mg/d, and dapagliflozin 10mg/d. However, it is important to note that further well-designed RCTs with larger sample sizes are necessary to verify and optimize the current body of evidence.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023396023.

Long-term observation of estimated fluid volume reduction after the initiation of ipragliflozin in patients with type 2 diabetes mellitus: a sub-analysis from a randomized controlled trial (PROTECT)

BACKGROUNDS/AIM

Recent studies have shown that the addition of sodium-glucose co-transporter 2 (SGLT2) inhibitors gradually reduces the estimated fluid volume parameters in a broad range of patient populations, suggesting that this mediates the clinical benefits of SGLT2 inhibitors in preventing heart failure. Here, we sought to examine the long-term (24 months) effect of the SGLT2 inhibitor ipragliflozin on the estimated fluid volume parameters in patients with type 2 diabetes mellitus (T2DM).

METHODS

In this prespecified sub-analysis of the PROTECT (Prevention of Atherosclerosis by SGLT2 Inhibitor: Multicenter, Randomized Controlled Study) trial, which was an investigator-initiated, multicenter, prospective, randomized, open-label, clinical trial primarily designed to evaluate the effect of ipragliflozin treatment administered for 24 months on carotid atherosclerosis in patients with T2DM, we evaluated serial changes in estimated plasma volume (ePV, %) calculated using the Straus formula and estimated extracellular volume (eEV, mL) calculated by the body surface area by 24 months following the initiation of 50-mg ipragliflozin once daily and compared them with those following standard care for T2DM (non-SGLT2 inhibitor use).

RESULTS

This sub-analysis included 464 patients (ipragliflozin, n = 232; control, n = 232), a full analysis set of the PROTECT trial. In an analysis using mixed-effects models for repeated measures, relative to the control group, ipragliflozin significantly reduced ePV by - 10.29% (95% confidence interval [CI]  - 12.47% to - 8.11%; P < 0.001) at 12 months and - 10.76% (95% CI - 12.86% to - 8.67%; P < 0.001) at 24 months. Additionally, ipragliflozin significantly reduced eEV by - 190.44 mL (95% CI - 249.09 to - 131.79 mL; P < 0.001) at 12 months and - 176.90 mL (95% CI  - 233.36 to - 120.44 mL; P < 0.001) at 24 months. The effects of ipragliflozin on these parameters over 24 months were mostly consistent across various patient clinical characteristics.

CONCLUSIONS

This prespecified sub-analysis from the PROTECT trial demonstrated that ipragliflozin treatment, compared with the standard care for T2DM, reduced two types of estimated fluid volume parameters in patients with T2DM, and the effect was maintained for 24 months. Our findings suggest that SGLT2 inhibitor treatment regulates clinical parameters incorporated into the calculating formulas analyzed and consequently fluid volume status for the long-term, and this may be at least partly associated with clinical benefits from chronic use of SGLT2 inhibitors. Trial registration Japan Registry of Clinical Trials, ID jRCT1071220089.

Fluid homeostasis induced by sodium-glucose cotransporter 2 inhibitors: novel insight for better cardio-renal outcomes in chronic kidney disease

Hypertension in chronic kidney disease (CKD) patients is a risk factor for end-stage renal disease, cardiovascular events, and mortality. Thus, the prevention and appropriate management of hypertension in these patients are essential strategies for better cardio-renal outcomes. In this review, we show novel risk factors for hypertension with CKD, several promising prognostic markers and treatment for cardio-renal outcomes. Of note, the clinical use of sodium-glucose cotransporter 2 (SGLT2) inhibitors has recently expanded to non-diabetic patients with CKD and heart failure as well as diabetic patients. SGLT2 inhibitors have an antihypertensive effect, but are also associated with a low risk of hypotension. This unique mechanism of blood pressure regulation by SGLT2 inhibitors may partially depend on body fluid homeostasis, which is mediated by the autoregulation property between "accelerator" (diuretic action) and "brake" (increase in anti-diuretic hormone vasopressin and fluid intake). Mineralocorticoid receptor (MR) blockers are used in the treatment of essential hypertension and hyperaldosteronism. Recently, a new MR blocker, finerenone, has been launched as a treatment for CKD with type 2 diabetes. These advances in relation to hypertension in CKD may contribute to the reduction of renal and cardiovascular events.

Mechanisms underlying the blood pressure-lowering effects of empagliflozin, losartan and their combination in people with type 2 diabetes: A secondary analysis of a randomized crossover trial

AIM

To study the effects of the sodium-glucose co-transporter-2 (SGLT2) inhibitor empagliflozin, the angiotensin receptor blocker (ARB) losartan, and their combination on blood pressure, while studying the mechanisms potentially involved.

METHODS

A total of 24 people with type 2 diabetes (T2D) (age: 66 ± 6 years; body mass index: 31.0 ± 3 kg/m² ; estimated glomerular filtration rate: 90 ml/min/1.73m² ) received a 1-week treatment with empagliflozin 10 mg once daily, losartan 50 mg once daily, their combination, and placebo, in a randomized double-blind crossover design, with 4-week washout periods in between. Blood pressure, arterial stiffness, autonomic nervous system activity and plasma volume, extracellular fluid and serum albumin were assessed.

RESULTS

Versus placebo (139 mmHg), empagliflozin reduced systolic blood pressure (SBP) by 8 mmHg (P = .001), losartan by 12 mmHg (P = .001) and empagliflozin + losartan by 15 mmHg (P < .001). Combination therapy had a larger SBP-lowering effect versus empagliflozin monotherapy (-7 [95% CI -12; -2] mmHg) and numerically larger effects versus losartan monotherapy (-3 [-8; 2] mmHg). Empagliflozin reduced sympathetic nervous system (SNS) activity, arterial stiffness and extracellular fluid, while increasing serum albumin. Losartan reduced SNS activity and arterial stiffness. Combination therapy induced volume contraction variables, together with a reduction in SNS activity and arterial stiffness.

CONCLUSION

In people with T2D, SGLT2 inhibition in combination with an ARB had a larger blood pressure-lowering effect versus placebo than either of the drugs alone. Our data further suggest that the mechanisms underlying these blood pressure reductions at least partially differ between these agents.

Pleiotropic effect of sodium-glucose cotransporter 2 inhibitors on blood pressure

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been incorporated as guideline-directed medical therapy for heart failure with reduced ejection fraction. Recent trials clearly established the efficacy of SGLT2 inhibitors on cardiac remodeling while preventing renal function decline in patients with or without diabetes mellitus. Blood pressure reduction during SGLT2 inhibitors use has been proposed through pleiotropic pathways and as a potential contributor that translates to cardiovascular benefits. The mechanisms underlying this decrease in blood pressure are not simply glycemic control. Orchestrating fluid status, modulation of sodium content and renin-angiotensin-activation system, anti-fibrosis and anti-inflammatory effect, ameliorating the characteristics of metabolic syndrome, as well as restoration of circadian rhythm all contributed to the BP lowering effect by SGLT2 inhibitors. Although SGLT2 inhibitors has not been demonstrated as anti-hypertensive agents thus far, their effects on BP alteration are clinically significant. In this review, we revisited the evidence correlating SGLT2 inhibitor use with blood pressure level. Future research directions will focus on the signaling pathway of SGLT2 inhibitors for fluid removal, atherosclerosis, vasoconstriction, and eventually hypertension.

Effect of sodium-glucose cotransporter-2 inhibitors on aldosterone and renin levels in diabetes mellitus type 2 patients: a systematic review and meta-analysis

The effect of sodium-glucose cotransporter-2 inhibitors (SGLT2i) on plasma aldosterone concentration (PAC) and plasma renin activity (PRA) levels are still inconclusive. This meta-analysis aimed to demonstrate the changes in PAC and PRA levels after the use of SGLT2i in type 2 diabetes patients. A search for relevant publications was performed using PubMed/Medline, Scopus, Cochrane, and Embase databases from their inception through May 2022. Inclusion criteria were studies that contained data on crude PAC and PRA levels before and after the use of SGLT2i in adult type 2 diabetes patients. Standardized mean difference (SMD) with a 95% confidence interval (95% CI) was calculated. Data was separately analyzed by study design: randomized controlled study (RCT) and non-randomized controlled study (non-RCT). Ten studies involving 380 patients were included with two RCT and eight non-RCT. Serum PAC levels showed no significant change after the use of SGLT2i in both RCT and non-RCT. Significantly higher PRA levels were observed after the use of SGLT2i in both RCT and non-RCT with SMD of 0.40 ng/mL/hr; 95% CI (0.06, 0.74) and SMD of 0.36 ng/mL/hr; 95%CI (0.17, 0.55), respectively. Subgroup analysis found significantly higher PRA levels after the use of SGLT2i (SMD 0.45 ng/mL/hr; 95% CI (0.18, 0.71)) only in subgroups that used for three months or less. The use of SGLT2i in diabetes mellitus type 2 patients can affect PRA levels, especially during short-term use. PRA levels should be interpreted with caution in this population.

Effects of dapagliflozin on volume status and systemic haemodynamics in patients with chronic kidney disease without diabetes: Results from DAPASALT and DIAMOND

AIMS

To assess the effect of sodium-glucose cotransporter-2 inhibitor dapagliflozin on natriuresis, blood pressure (BP) and volume status in patients with chronic kidney disease (CKD) without diabetes.

MATERIALS AND METHODS

We performed a mechanistic open-label study (DAPASALT) to evaluate the effects of dapagliflozin on 24-hour sodium excretion, 24-hour BP, extracellular volume, and markers of volume status during a standardized sodium diet (150 mmol/d) in six patients with CKD. In parallel, in a placebo-controlled double-blind crossover trial (DIAMOND), we determined the effects of 6 weeks of dapagliflozin on markers of volume status in 53 patients with CKD.

RESULTS

In DAPASALT (mean age 65 years, mean estimated glomerular filtration rate [eGFR] 39.4 mL/min/1.73 m² , median urine albumin:creatinine ratio [UACR] 111 mg/g), dapagliflozin did not change 24-hour sodium and volume excretion during 2 weeks of treatment. Dapagliflozin was associated with a modest increase in 24-hour glucose excretion on Day 4, which persisted at Day 14 and reversed to baseline after discontinuation. Mean 24-hour systolic BP decreased by -9.3 (95% confidence interval [CI] -19.1, 0.4) mmHg after 4 days and was sustained at Day 14 and at wash-out. Renin, angiotensin II, urinary aldosterone and copeptin levels increased from baseline. In DIAMOND (mean age 51 years, mean eGFR 59.0 mL/min/1.73 m² , median UACR 608 mg/g), compared to placebo, dapagliflozin increased plasma renin (38.5 [95% CI 7.4, 78.8]%), aldosterone (19.1 [95% CI -5.9, 50.8]%), and copeptin levels (7.3 [95% CI 0.1, 14.5] pmol/L).

CONCLUSIONS

During a standardized sodium diet, dapagliflozin decreased BP but did not increase 24-hour sodium and volume excretion. The lack of increased natriuresis and diuresis may be attributed to activation of intra-renal compensatory mechanisms to prevent excessive water loss.

Differential In Vitro Effects of SGLT2 Inhibitors on Mitochondrial Oxidative Phosphorylation, Glucose Uptake and Cell Metabolism

(1) The cardio-reno-metabolic benefits of the SGLT2 inhibitors canagliflozin (cana), dapagliflozin (dapa), ertugliflozin (ertu), and empagliflozin (empa) have been demonstrated, but it remains unclear whether they exert different off-target effects influencing clinical profiles. (2) We aimed to investigate the effects of SGLT2 inhibitors on mitochondrial function, cellular glucose-uptake (GU), and metabolic pathways in human-umbilical-vein endothelial cells (HUVECs). (3) At 100 µM (supra-pharmacological concentration), cana decreased ECAR by 45% and inhibited GU (IC5o: 14 µM). At 100 µM and 10 µM (pharmacological concentration), cana increased the ADP/ATP ratio, whereas dapa and ertu (3, 10 µM, about 10× the pharmacological concentration) showed no effect. Cana (100 µM) decreased the oxygen consumption rate (OCR) by 60%, while dapa decreased it by 7%, and ertu and empa (all 100 µM) had no significant effect. Cana (100 µM) inhibited GLUT1, but did not significantly affect GLUTs’ expression levels. Cana (100 µM) treatment reduced glycolysis, elevated the amino acids supplying the tricarboxylic-acid cycle, and significantly increased purine/pyrimidine-pathway metabolites, in contrast to dapa (3 µM) and ertu (10 µM). (4) The results confirmed cana´s inhibition of mitochondrial activity and GU at supra-pharmacological and pharmacological concentrations, whereas the dapa, ertu, and empa did not show effects even at supra-pharmacological concentrations. At supra-pharmacological concentrations, cana (but not dapa or ertu) affected multiple cellular pathways and inhibited GLUT1.

Sodium glucose cotransporter-2 inhibitors protect the cardiorenal axis: Update on recent mechanistic insights related to kidney physiology

Sodium glucose cotransporter-2 (SGLT2) inhibitors have acquired a central role in the treatment of type 2 diabetes, chronic kidney disease including diabetic kidney disease, and heart failure with reduced ejection fraction. SGLT2 inhibitors lower glucose levels by inducing glycosuria. In addition, SGLT2 inhibitors improve cardiovascular outcomes (3-point MACE), end-stage kidney disease, hospitalization for heart failure, and cardiovascular mortality in people with and without diabetes. The mechanisms underlying these benefits have been extensively investigated, but remain poorly understood. In this review, we first summarize recent trial evidence and subsequently focus on (1) the mechanisms by which SGLT2 inhibitors improve kidney outcomes and (2) the potential role of the kidneys in mediating the cardioprotective effects of SGLT2 inhibitors.

Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Water and Sodium Metabolism

Sodium-glucose cotransporter 2 (SGLT2) inhibitors exert hypoglycemic and diuretic effects by inhibiting the absorption of sodium and glucose from the proximal tubule. Currently available data indicate that SGLT2 inhibitors transiently enhance urinary sodium excretion and urinary volume. When combined with loop diuretics, SGLT2 inhibitors exert a synergistic natriuretic effect. The favorable diuretic profile of SGLT2 inhibitors may confer benefits to volume management in patients with heart failure but this natriuretic effect may not be the dominant mechanism for the superior long-term outcomes observed with these agents in patients with heart failure. The first part of this review explores the causes of transient natriuresis and the diuretic mechanisms of SGLT2 inhibitors. The second part provides an overview of the synergistic effects of combining SGLT2 inhibitors with loop diuretics, and the third part summarizes the mechanisms of cardiovascular protection associated with the diuretic effects of SGLT2 inhibitors.

Effects of 1-year treatment with canagliflozin on body composition and total body water in patients with type 2 diabetes

AIM

To characterize the long-term changes in body composition associated with sodium-glucose cotransporter-2 (SGLT2) inhibitors.

MATERIALS AND METHODS

In this multicentre, single-arm, open-label study, 107 patients with type 2 diabetes were treated with canagliflozin 100 mg, as add-on therapy, for 12 months. Body composition was measured with a body composition analyser (T-SCAN PLUS) using the impedance method to prospectively analyse changes in body components, including percentage of body fat, body fat mass, total body water, muscle mass and mineral mass. Estimated plasma volume (PV) was calculated using the Kaplan formula.

RESULTS

Body weight showed a significant decrease from 1 month to 12 months of treatment with canagliflozin, with a higher rate of decrease in body fat in body composition. A significant decrease in mineral mass was also observed, but its rate was low. Following treatment with canagliflozin, changes in total body water did not affect intracellular water, and a significant decrease in extracellular water, including plasma components, was observed early and was sustained up to 12 months. Protein mass, a component of muscle mass, was not affected, with only a slight decrease in water volume observed.

CONCLUSIONS

Canagliflozin decreased extracellular fluid and PV in addition to decreasing fat in the body via calorie loss resulting from urinary glucose excretion. This study suggested that SGLT2 inhibitors might reduce body weight by regulating fat mass or water distribution in the body and might have cardiac and renal protective effects by resetting the homeostasis of fluid balance.

The diuretic effects of SGLT2 inhibitors: A comprehensive review of their specificities and their role in renal protection

Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are new oral glucose-lowering agents that provide cardiovascular and renal protection in both patients with and without type 2 diabetes. Because of their unique mechanism of action, increased glucosuria is associated with osmotic diuresis and some natriuresis, yet the latter seems mostly transient. The potential role of the diuretic effect in overall cardiovascular and renal protection by SGLT2is remains a matter of debate. Precise evaluation of the diuretic effect is not so easy and most studies relied upon indirect estimations that led to divergent results, presumably also explained by different study designs and population characteristics. Everybody agrees upon the fact that SGLT2is are different from other classical diuretics (thiazides and loop diuretics) as they present some favourable properties, i.e. reduced sympathetic activity, preserved potassium balance, lower risk of acute renal injury, decrease of serum uric acid level. The potential role of the diuretic effect of SGLT2is on renal outcomes is still unclear, yet their ability to reduce albuminuria and dampen the risk of heart failure may contribute to improve renal prognosis besides other complex underlying mechanisms. In this comprehensive review we first critically analyse the results obtained with indirect methods that assess a diuretic effect of SGLT2is, second we describe the specificities of the diuretic activity of SGLT2is compared with other classical diuretics, and third we discuss the potential mechanisms by which the diuretic effect of SGLT2is could contribute to the improvement of renal outcomes consistently reported with this innovative amazing pharmacological class.

Do sodium-glucose co-transporter-2 inhibitors increase plasma glucagon by direct actions on the alpha cell? And does the increase matter for the associated increase in endogenous glucose production?

Sodium-glucose co-transporter-2 inhibitors (SGLT2is) lower blood glucose and are used for treatment of type 2 diabetes. However, SGLT2is have been associated with increases in endogenous glucose production (EGP) by mechanisms that have been proposed to result from SGLT2i-mediated increases in circulating glucagon concentrations, but the relative importance of this effect is debated, and mechanisms possibly coupling SGLT2is to increased plasma glucagon are unclear. A direct effect on alpha-cell activity has been proposed, but data on alpha-cell SGLT2 expression are inconsistent, and studies investigating the direct effects of SGLT2 inhibition on glucagon secretion are conflicting. By contrast, alpha-cell sodium-glucose co-transporter-1 (SGLT1) expression has been found more consistently and appears to be more prominent, pointing to an underappreciated role for this transporter. Nevertheless, the selectivity of most SGLT2is does not support interference with SGLT1 during therapy. Paracrine effects mediated by secretion of glucagonotropic/static molecules from beta and/or delta cells have also been suggested to be involved in SGLT2i-induced increase in plasma glucagon, but studies are few and arrive at different conclusions. It is also possible that the effect on glucagon is secondary to drug-induced increases in urinary glucose excretion and lowering of blood glucose, as shown in experiments with glucose clamping where SGLT2i-associated increases in plasma glucagon are prevented. However, regardless of the mechanisms involved, the current balance of evidence does not support that SGLT2 plays a crucial role for alpha-cell physiology or that SGLT2i-induced glucagon secretion is important for the associated increased EGP, particularly because the increase in EGP occurs before any rise in plasma glucagon.

Relationship Between HbA1c Level and Effectiveness of SGLT2 Inhibitors in Decompensated Heart Failure Patients with Type 2 Diabetes Mellitus

The DAPA-HF trial demonstrated that sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduced worsening heart failure (HF) events in chronic HF patients with or without type 2 diabetic mellitus (T2DM). However, it remains unclear whether the effectiveness of SGLT2i is also observed in patients with decompensated HF irrespective of HbA1c level. Eighty-one T2DM patients hospitalized due to decompensated HF were enrolled and divided into 2 groups according to their HbA1c levels (group H, HbA1c 6.9-13.0%, n = 41; group L, HbA1c < 6.9%, n = 40). After the initial management of HF, one of the SGLT2i (canagliflozin 100 mg/day or dapagliflozin 5 mg/day or empagliflozin 10 mg/day) was non-randomly administered, and clinical parameters associating with HF and T2DM were followed for 7 days. No symptomatic hypoglycemia was observed in any patient. In both groups, urine glucose excretion was increased significantly after the administration of SGLT2i. However, its amount was greater in group H than group L. Urine volume was increased significantly at day 1 in both groups. Urine volume returned to the baseline after one week in group L. In contrast, the increase in urine volume persisted at least for one week in group H. Of note, a decrease in B-type natriuretic peptide levels after the initiation of SGLT2i was observed in both groups similarly despite differences in urine output and excretion of urine glucose. In conclusion, SGLT2i can improve decompensated HF in patients with T2DM irrespective of the HbA1c level.

A kidney perspective on the mechanism of action of sodium glucose co-transporter 2 inhibitors

Sodium glucose co-transporter (SGLT) 2 inhibitors reduce the risk of kidney failure in patients with and without type 2 diabetes (T2D). Although the precise underlying mechanisms for these nephroprotective effects are incompletely understood, various hypotheses have been proposed including reductions in intraglomerular pressure through restoration of tubuloglomerular feedback, blood pressure reduction and favorable effects on vascular function, reduction in tubular workload and hypoxia, and metabolic effects resulting in increased autophagy. Here, we review these mechanisms, which may also explain the beneficial effects of SGLT2 inhibitors on kidney function in patients without T2D.

Natriuretic Effect of Two Weeks of Dapagliflozin Treatment in Patients With Type 2 Diabetes and Preserved Kidney Function During Standardized Sodium Intake: Results of the DAPASALT Trial

OBJECTIVE

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk for heart failure hospitalization potentially by inducing sodium excretion, osmotic diuresis, and plasma volume contraction. Few studies have investigated this hypothesis, but none have assessed cumulative sodium excretion with SGLT2 inhibition during standardized sodium intake in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

The DAPASALT trial was a mechanistic, nonrandomized, open-label study in patients with type 2 diabetes with preserved kidney function on a controlled standardized sodium diet (150 mmol/day). It evaluated the effects of dapagliflozin on sodium excretion, 24-h blood pressure, and extracellular, intracellular, and plasma volumes at the start of treatment (ST) (days 2-4), end of treatment (ET) (days 12-14), and follow-up (FU) (days 15-18).

RESULTS

Fourteen patients were included in the efficacy analysis. Mean (SD) baseline sodium excretion (150 [32] mmol/24-h) did not significantly change during treatment (change at ST: -7.0 mmol/24-h [95% CI -22.4, 8.4]; change at ET: 2.1 mmol/24-h [-28.8, 33.0]). Mean baseline 24-h systolic blood pressure was 128 (10) mmHg and significantly reduced at ST (-6.1 mmHg [-9.1, -3.1]; P < 0.001) and ET (-7.2 mmHg [-10.0, -4.3]; P < 0.001). Dapagliflozin did not significantly alter plasma volume or intracellular volume, while extracellular volume changed at ST (-0.7 L [-1.3, -0.1]; P = 0.02). As expected, 24-h urinary glucose excretion significantly increased during dapagliflozin treatment and reversed during FU.

CONCLUSIONS

During standardized sodium intake, dapagliflozin reduced blood pressure without clear changes in urinary sodium excretion, suggesting that factors other than natriuresis and volume changes may contribute to the blood pressure-lowering effects.

Effect of sodium-glucose cotransporter-2 inhibitors on aldosterone-to-renin ratio in diabetic patients with hypertension: a retrospective observational study

BACKGROUND

Plasma aldosterone-to-renin ratio (ARR) is popularly used for screening primary aldosteronism (PA). Some medications, including diuretics, are known to have an effect on ARR and cause false-negative and false-positive results in PA screening. Currently, there are no studies on the effects of sodium-glucose cotransporter-2 (SGLT2) inhibitors, which are known to have diuretic effects, on ARR. We aimed to investigate the effects of SGLT2 inhibitors on ARR.

METHODS

We employed a retrospective design; the study was conducted from April 2016 to December 2018 and carried out in three hospitals. Forty patients with diabetes and hypertension were administered SGLT2 inhibitors. ARR was evaluated before 2 to 6 months after the administration of SGLT2 inhibitors to determine their effects on ARR.

RESULTS

No significant changes in the levels of ARR (90.9 ± 51.6 vs. 81.4 ± 62.9) were found. Body mass index, diastolic blood pressure, heart rate, fasting plasma glucose, and hemoglobin A1c were significantly decreased by SGLT2 inhibitors. Serum creatinine was significantly increased.

CONCLUSION

SGLT2 inhibitor administration yielded minimal effects on ARR and did not increase false-negative results in PA screening in patients with diabetes and hypertension more than 2 months after administration.

Effects of dapagliflozin on renin-angiotensin-aldosterone system under renin-angiotensin system inhibitor administration

Sodium-glucose cotransporter-2 inhibitors (SGLT2Is) are reported to prevent cardiovascular events by a mechanism possibly including diuresis and sodium excretion. In this respect, diuresis-induced compensatory upregulation of the renin-angiotensin-aldosterone (RAA) system should be clarified and we performed a randomized controlled trial using dapagliflozin, an SGLT2I. Hypertensive diabetic patients taking angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers were randomly assigned to a dapagliflozin group (DAPA) or a control group (CTRL) with the difference in the changes in plasma renin activity (PRA) after 24 weeks of the treatment as the primary outcome. PRA, plasma aldosterone concentration (PAC), age, sex, BMI, blood pressure, pulse rate, eGFRcys, and HbA1c were not different between the groups at baseline. After 24 weeks, the changes in the PRA from the baseline of the DAPA (n = 44) and CTRL (n = 39) groups were 6.30 ± 15.55 and 1.42 ± 11.43 ng/mL/h, respectively (p = 0.11) although the power of detection was too small. However, post hoc nonparametric analyses revealed that there was a definite increase in the PRA and PAC in the DAPA group (p < 0.0001 and p = 0.00025, respectively) but not in the CTRL group. The PRA in the DAPA group after 24 weeks treatment was significantly elevated compared to the CTRL group (p = 0.013) but not for the PAC. Accordingly, it would be suggested that dapagliflozin may not induce a profound increase, if any, in PAC after 24 weeks of treatment in hypertensive type 2 diabetic patients under RAA suppression.

SGLT2 inhibitors, sodium and off-target effects: an overview

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively new class of antidiabetic drugs that in addition to emerging as an effective antihyperglycemic treatment have been shown to improve, in several trials, both renal and cardiovascular outcomes. In consideration of the renal site of action and the associated osmotic diuresis, a negative sodium balance has been postulated during SGLT2i administration. Actually, sodium and water depletion may contribute to some positive actions of SGLT2i but evidence is far from being conclusive and the real physiologic effects of SGLT2i on sodium remain largely unknown. Indeed, no study has yet investigated how SGLT2i change sodium balance in the long term and especially the pathways through which the natriuretic effect is expressed. Furthermore, several experimental studies have recently identified different pathways, not directly linked to tubular sodium handling, which could contribute to the renal and cardiovascular benefits associated with SGLT2i. This paper will review the evidence of SGLT2i action on sodium transporters, their off-target effects and their potential role on kidney protection.

Sodium-glucose cotransporter-2 inhibitors: Understanding the mechanisms for therapeutic promise and persisting risks

In a healthy person, the kidney filters nearly 200 g of glucose per day, almost all of which is reabsorbed. The primary transporter responsible for renal glucose reabsorption is sodium-glucose cotransporter-2 (SGLT2). Based on the impact of SGLT2 to prevent renal glucose wasting, SGLT2 inhibitors have been developed to treat diabetes and are the newest class of glucose-lowering agents approved in the United States. By inhibiting glucose reabsorption in the proximal tubule, these agents promote glycosuria, thereby reducing blood glucose concentrations and often resulting in modest weight loss. Recent work in humans and rodents has demonstrated that the clinical utility of these agents may not be limited to diabetes management: SGLT2 inhibitors have also shown therapeutic promise in improving outcomes in heart failure, atrial fibrillation, and, in preclinical studies, certain cancers. Unfortunately, these benefits are not without risk: SGLT2 inhibitors predispose to euglycemic ketoacidosis in those with type 2 diabetes and, largely for this reason, are not approved to treat type 1 diabetes. The mechanism for each of the beneficial and harmful effects of SGLT2 inhibitors-with the exception of their effect to lower plasma glucose concentrations-is an area of active investigation. In this review, we discuss the mechanisms by which these drugs cause euglycemic ketoacidosis and hyperglucagonemia and stimulate hepatic gluconeogenesis as well as their beneficial effects in cardiovascular disease and cancer. In so doing, we aim to highlight the crucial role for selecting patients for SGLT2 inhibitor therapy and highlight several crucial questions that remain unanswered.

Canagliflozin Increases Calorie Intake in Type 2 Diabetes Without Changing the Energy Ratio of the Three Macronutrients: CANA-K Study

Background: Sodium/glucose cotransporter-2 (SGLT2) inhibitors improve glycemic control and reduce body weight by increasing glycosuria. Although a compensatory increase of food intake has been reported, the long-term effect of SGLT2 inhibitors on food intake remains unclear. This study investigated the influence of canagliflozin on calorie and nutrient intake over 1 year. Materials and Methods: Patients with type 2 diabetes (n = 107) were enrolled and followed prospectively while receiving canagliflozin at 100 mg/day for 12 months. Intake of nutrients was investigated by using the food frequency questionnaire. Hemoglobin A1c, body weight, and satisfaction with diabetes treatment (assessed by the Diabetes Treatment Satisfaction Questionnaire: DTSQ) were also investigated. Results: The baseline total energy intake was 1723 ± 525 kcal/day and it showed a persistent increase during treatment with canagliflozin, being 132 kcal higher at 6 months (P = 0.0058) and 113 kcal higher at 12 months (P = 0.0516). Intake of all three macronutrients (carbohydrate, protein, and fat) was significantly increased after 6 months of canagliflozin treatment (P = 0.0129, P = 0.0160, and P = 0.0314, respectively), but their ratio was unchanged. The DTSQ score improved significantly and both hemoglobin A1c and body weight showed a significant decrease throughout treatment (all P < 0.0001). Conclusions: After patients with type 2 diabetes commenced canagliflozin, their calorie intake increased without changing the ratio of the three macronutrients. Despite elevation of the calorie intake, glycemic control improved and weight loss was achieved. Satisfaction with treatment of diabetes also increased.

A new HPLC-MS/MS method for the simultaneous quantification of SGLT2 inhibitors and metformin in plasma and its application to a pharmacokinetic study in healthy volunteers

Monitoring the plasma concentrations of metformin and sodium-glucose cotransporter-2 inhibitors (canagliflozin, dapagliflozin and empagliflozin) is essential for pharmacokinetic and bioequivalence studies and therapeutic monitoring. The present work therefore aimed to develop and validate a high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) method for the simultaneous quantification of these drugs in human plasma. The analyses were performed using an Agilent 1200 HPLC system coupled to an Applied Biosystems API 3200 triple quadrupole MS/MS with electrospray ionization in positive ion mode. After one-step protein precipitation of plasma with acetonitrile containing 0.1% formic acid, chromatographic separation was achieved on an Xbridge C₁₈ column, with a mobile phase consisting of a gradient of water and acetonitrile, both containing 1 mm ammonium formate and 0.1% formic acid. Quantification was performed in multiple reaction monitoring mode using m/z 130.1 → 71.1 for metformin, m/z 462.0 → 191.2 for canagliflozin, m/z 426.1 → 167.1 for dapagliflozin and m/z 468.0 → 354.9 for empagliflozin. The proposed method was validated and demonstrated to be adequate for the quantification of metformin, canagliflozin, dapagliflozin and empagliflozin for clinical monitoring, pharmacokinetics and bioequivalence studies.

Rationale and Design of the CANONICAL Study - Randomized, Open-Label Study to Evaluate the Efficacy and Safety of Canagliflozin for Heart Failure With Preserved Ejection Fraction With Type 2 Diabetes Mellitus

Background: Sodium-glucose cotransporter 2 inhibitors (SGLT2-I) have beneficial cardiovascular effects, including reduction in hospitalization for heart failure (HF). The aim of this study is to explore the efficacy and safety of canagliflozin compared with standard diabetes treatment in elderly patients with type 2 diabetes (T2DM) and HF with preserved ejection fraction (HFpEF).

Methods and Results: This is a multicenter, randomized, open-label, parallel-group comparison study designed to evaluate the effects of canagliflozin on fluid retention and cardiac function in T2DM patients with HFpEF. Eligible participants are patients aged ≥65 years with insufficient glycemic control. Qualified patients will be randomly assigned to treatment with 100 mg of canagliflozin or standard diabetic treatment other than SGLT2-I; both groups will be treated for 24 weeks. The primary endpoints are changes in body weight as an indicator of fluid retention and plasma brain natriuretic peptide as an indicator of cardiac function. The secondary endpoints include cardiovascular event rates, changes in the dose of loop diuretics, echocardiographic left ventricular function, and nutritional status.

Conclusions: This study is expected to provide valuable findings regarding the mechanisms of canagliflozin on cardiac function and a potential new therapeutic approach for HFpEF. (UMIN000028668 and jRCTs051180030)

Comparative safety of the sodium glucose co-transporter 2 (SGLT2) inhibitors: a systematic review and meta-analysis

OBJECTIVE

To estimate the association between the use of sodium glucose co-transporter-2 (SGLT2) inhibitors and postmarket harms as identified by drug regulatory agencies.

DESIGN

We conducted a systematic review and meta-analysis of randomised controlled trials (RCT). Six large databases were searched from inception to May 2018. Random effects models were used to estimate pooled relative risks (RRs).

INTERVENTION

SGLT2 inhibitors, compared with placebo or active comparators.

PRIMARY OUTCOMES

Acute kidney injury (AKI), diabetic ketoacidosis (DKA), urinary tract infections (UTI), bone fractures and lower limb amputations.

RESULTS

We screened 2418 citations of which 109 were included. Most studies included one of four SGLT2 inhibitors, dapagliflozin, canagliflozin, empagliflozin and ipragliflozin. When compared with placebo, SGLT2 inhibitors were found to be significantly protective against AKI (RR=0.59; 95% CI 0.39 to 0.89; I2=0.0%), while no difference was found for DKA (RR 0.66; 95% CI 0.30 to 1.45, I2=0.0%), UTI (RR 1.02; 95% CI 0.95 to 1.09, I2=0.0%) or bone fracture (RR 0.87; 95% CI 0.69 to 1.09, I2=1.3%). Three studies reported on amputation, with one finding a significant increase risk. No increased risk for either outcome was found when compared with active controls. Subgroup analysis did show an increased risk of UTI with dapagliflozin only (RR 1.21; 95% CI 1.02 to 1.43, I2=0.0%), but no other analysis supported an increased risk of AKI, DKA, UTI or fracture.

CONCLUSIONS

Current evidence from RCTs does not suggest an increased risk of harm with SGLT2 inhibitors as a class over placebo or active comparators with respect to AKI, DKA, UTI or fracture. However, wide CIs for many comparisons suggest limited precision, and therefore clinically important adverse events cannot be ruled out. Dapagliflozin, appears to independently increase the risk of UTI, although the mechanism for this intraclass variation in risk is unclear.

PROSPERO REGISTRATION NUMBER

CRD42016038715.

Diuretic Effects of Sodium Glucose Cotransporter 2 Inhibitors and Their Influence on the Renin-Angiotensin System

The renin-angiotensin system (RAS) plays an important role in regulating body fluids and blood pressure. However, inappropriate activation of the RAS contributes to the pathogenesis of cardiovascular and renal diseases. Recently, sodium glucose cotransporter 2 (SGLT2) inhibitors have been used as anti-diabetic agents. SGLT2 inhibitors induce glycosuria and improve hyperglycemia by inhibiting urinary reabsorption of glucose. However, in the early stages of treatment, these inhibitors frequently cause polyuria and natriuresis, which potentially activate the RAS. Nevertheless, the effects of SGLT2 inhibitors on RAS activity are not straightforward. Available data indicate that treatment with SGLT2 inhibitors transiently activates the systemic RAS in type 2 diabetic patients, but not the intrarenal RAS. In this review article, we summarize current evidence of the diuretic effects of SGLT2 inhibitors and their influence on RAS activity.

Dose response of sodium glucose cotransporter-2 inhibitors in relation to urinary tract infections: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

The sodium glucose cotransporter-2 (SGLT2) inhibitors are a novel group of drugs for treatment of type 2 diabetes mellitus. We investigated whether there is a dose-response relation between SGLT2 inhibitors and urinary tract infections (UTIs) in patients with type 2 diabetes, relative to other diabetes therapies or placebo.

METHODS

We conducted a systematic review and network meta-analysis of randomized controlled trials (RCTs) of SGLT2 inhibitors in patients with type 2 diabetes. We searched 6 databases and the reference lists of key papers. We included studies with placebo or active antidiabetic comparators that reported the outcome of UTI, and established thresholds for high and low doses of SGLT2 inhibitors. We used a random-effects model to estimate the pooled effect estimates and 95% credible intervals.

RESULTS

We screened 2418 citations and included 105 references for studies of 8 unique SGLT2 inhibitors, representing 60 082 individuals (with a total of 4348 UTIs). Most mixed-treatment comparisons showed no significant difference in risk of UTI, with the exception of high-dose dapagliflozin (≥ 10 mg) compared with placebo (odds ratio [OR] 1.30, 95% credible interval 1.09-1.57), with active comparators (OR 1.44, 95% credible interval 1.15-1.79), with empagliflozin at both low (OR 1.30, 95% credible interval 1.04-1.60) and high (OR 1.39, 95% credible interval 1.12-1.72) doses, and with low-dose ertugliflozin (OR 1.43, 95% credible interval 1.01-2.01). When the analysis was restricted to RCTs with a low risk of bias, the results were nonsignificant.

INTERPRETATION

Current RCT evidence does not suggest a dose-response relation between most SGLT2 inhibitors and UTIs, with the exception of dapagliflozin. Further research is needed to quantify the relation between SGLT2 inhibitors and more serious infections.

TRIAL REGISTRATION

PROSPERO registration no. CRD42016038715.

Systematic Review of Efficacy and Safety of Newer Antidiabetic Drugs Approved from 2013 to 2017 in Controlling HbA1c in Diabetes Patients

Type 2 Diabetes Mellitus (T2DM) is the most common form of diabetes mellitus and accounts for about 95% of all diabetes cases. Many newer oral as well as parenteral antidiabetic drugs have been introduced in to the market in recent years to control hyperglycemic conditions in diabetes patients and many of these drugs produce potential side effects in diabetes patients. Hence, this systematic review was aimed to analyze and compare the efficacy and safety of oral antidiabetic agents in controlling HbA1c in T2DM patients, that were approved by the United States-Food and Drug Administration (US-FDA) from 2013 to 2017. All randomized controlled, double-blind trials published in English during the search period involving the newer antidiabetic agents were selected. In the outcome assessment comparison, semaglutide demonstrated the highest efficacy in lowering HbA1c, with a 1.6% reduction (p < 0.0001) when given at a dose of 1.0 mg. The safety profile of all the agents as compared to placebo or control were similar, with no or slight increase in the occurrence of adverse events (AEs) but no fatal reaction was reported. The most common AEs of all the antidiabetic agents were gastrointestinal in nature, with several cases of hypoglycemic events. However, among all these agents, semaglutide seems to be the most efficacious drug to improve glycemic control in terms of HbA1c. Alogliptin has the least overall frequency of AEs compared to other treatment groups.

Canagliflozin for the treatment of type 2 diabetes: a comparison between Japanese and non-Japanese patients

INTRODUCTION

Canagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor, improves various cardiometabolic parameters. Although canagliflozin was originally discovered in Japan, no comprehensive summary of its effects in Japanese patients has been reported. As differences exist in the pathologic features of diabetes between Japanese and non-Japanese populations, it is important to consolidate Japanese data for canagliflozin. Areas covered: The authors summarize Japanese clinical trial and post-marketing surveillance data for canagliflozin, and make comparisons with non-Japanese data. They also consider the therapeutic potential of canagliflozin in Japanese patients by presenting results from the CANagliflozin cardioVascular Assessment Study (CANVAS) Program. Expert opinion: In Japanese patients, canagliflozin 100 mg, administered as monotherapy or combination therapy, improved blood glucose, body weight, and blood pressure, and was well tolerated; the efficacy and safety profiles were comparable to previous clinical studies in other countries. In the CANVAS Program, canagliflozin reduced major cardiovascular events, and although Japan was not included in this program, canagliflozin may have cardiovascular benefits in Japanese patients, in whom control of multiple risk factors is important for preventing diabetic complications. Patients with high cardiovascular risk often have multiple comorbidities, so it is important to consider the risk-benefit balance of using SGLT2 inhibitors in individual patients.

Plasma Pharmacokinetic Determination of Canagliflozin and Its Metabolites in a Type 2 Diabetic Rat Model by UPLC-MS/MS

Canagliflozin is a novel, orally selective inhibitor of sodium-dependent glucose co-transporter-2 (SGLT2) for the treatment of patients with type 2 diabetes mellitus. In this study, a sensitive and efficient UPLC-MS/MS method for the quantification of canagliflozin and its metabolites in rat plasma was established and applied to pharmacokinetics in a type 2 diabetic rat model. We firstly investigated the pharmacokinetic changes of canagliflozin and its metabolites in type 2 diabetic rats in order to use canagliflozin more safely, reasonably and effectively. We identified three types of O-glucuronide metabolites (M5, M7 and M17), two kinds of oxidation metabolites (M8 and M9) and one oxidation and glucuronide metabolite (M16) using API 5600 triple-TOF-MS/MS. Following liquid–liquid extraction by tert-butyl methyl ether, chromatographic separation of canagliflozin and its metabolites were performed on a Waters XBridge BEH C18 column (100 × 2.1 mm, 2.5 μm) using 0.1% acetonitrile–formic acid (75:15, v/v) as the mobile phase at a flow rate of 0.7 mL/min. Selected ion monitoring transitions of m/z 462.00→191.10, 451.20→153.10, 638.10→191.10 and 478.00→267.00 were chosen to quantify canagliflozin, empagliflozin (IS), O-glucuronide metabolites (M5, M7 and M17), and oxidation metabolites (M9) using an API 5500-triple-MS/MS in the positive electrospray ionization mode. The validation of the method was found to be of sufficient specificity, accuracy and precision. The pathological condition of diabetes could result in altered pharmacokinetic behaviors of canagliflozin and its metabolites. The pharmacokinetic parameters (AUC_0–t, AUC_0–∞, CL_z/F, and V_z/F) of canagliflozin were significantly different between the CTRL and DM group rats (p < 0.05 or p < 0.01), which may subsequently cause different therapeutic effects.

High Basolateral Glucose Increases Sodium-Glucose Cotransporter 2 and Reduces Sirtuin-1 in Renal Tubules through Glucose Transporter-2 Detection

Under diabetic conditions, sodium-glucose cotransporter 2 (SGLT2) for glucose uptake in proximal tubules (PTs) increases, whereas NAD⁺-dependent protein deacetylase silent mating type information regulation 2 homolog 1 (Sirtuin-1; SIRT1) for PT survival decreases. Therefore, we hypothesized that increased glucose influx by SGLT2 reduces SIRT1 expression. To test this hypothesis, db/db mice with diabetes and high-glucose (HG)-cultured porcine PT LLC-PK1 cells in a two-chamber system were treated with the SGLT2 inhibitor canagliflozin. We also examined SIRT1 and SGLT2 expression in human kidney biopsies. In db/db mice, SGLT2 expression increased with concomitant decreases in SIRT1, but was inhibited by canagliflozin. For determination of the polarity of SGLT2 and SIRT1 expression, LLC-PK1 cells were seeded into Transwell chambers (pore size, 0.4 µm; Becton Dickinson, Oxford, UK). HG medium was added to either or to both of the upper and lower chambers, which corresponded to the apical and basolateral sides of the cells, respectively. In this system, the lower chamber with HG showed increased SGLT2 and decreased SIRT1 expression. Canagliflozin reversed HG-induced SIRT1 downregulation. Gene silencing and inhibitors for glucose transporter 2 (GLUT2) blocked HG-induced SGLT2 expression upregulation. Gene silencing for the hepatic nuclear factor-1α (HNF-1α), whose nuclear translocation was enhanced by HG, blocked HG-induced SGLT2 expression upregulation. Similarly, gene silencing for importin-α1, a chaperone protein bound to GLUT2, blocked HG-induced HNF-1α nuclear translocation and SGLT2 expression upregulation. In human kidney, SIRT1 immunostaining was negatively correlated with SGLT2 immunostaining. Thus, under diabetic conditions, SIRT1 expression in PTs was downregulated by an increase in SGLT2 expression, which was stimulated by basolateral HG through activation of the GLUT2/importin-α1/HNF-1α pathway.

Empagliflozin Induces Transient Diuresis Without Changing Long-Term Overall Fluid Balance in Japanese Patients With Type 2 Diabetes

INTRODUCTION

Empagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, ameliorates hyperglycemia in patients with type 2 diabetes (T2D) by inducing sustained glucosuria. Empagliflozin treatment was previously associated with a transient increase in 24-h urine volume in Caucasian patients with T2D, however comparable evidence in Japanese T2D individuals is scarce. We therefore assessed acute and chronic changes in 24-h urine volume and fluid intake with empagliflozin in Japanese patients with T2D.

METHODS

In this randomized, double-blind, placebo-controlled, parallel-group, multiple-dose, 4-week trial, 100 Japanese patients with T2D were randomized to receive either 1, 5, 10, or 25 mg empagliflozin or placebo once-daily. Changes from baseline in 24-h urine volume and fluid intake were assessed at days 1, 27, and 28 after the initiation of empagliflozin.

RESULTS

The 24-h urine volume and fluid intake were comparable across all treatment groups at baseline. Patients treated with either 10 or 25 mg empagliflozin (i.e., the licensed doses in Japan) showed a significant increase in 24-h urine volume compared to placebo at day 1 (mean change from baseline: + 0.83, + 1.08, and + 0.29 L/day in the empagliflozin 10 and 25 mg groups and the placebo group, respectively; both p < 0.001 vs. placebo). However, 24-h urine volume levels in the empagliflozin groups were comparable to placebo at day 27 and 28 (differences vs placebo < 0.1 L/day; p > 0.05). The 24-h fluid intake was comparable across all study groups throughout the entire study period. No events consistent with dehydration were reported during empagliflozin treatment.

CONCLUSION

Treatment initiation with empagliflozin in Japanese patients with T2D was associated with transient diuresis; however, overall urine volume returned towards baseline levels within 4 weeks of treatment. These findings are consistent with a physiological, adaptive mechanism of the kidney to maintain overall body fluid balance in response to treatment initiation with a SGLT2 inhibitor.

TRIAL REGISTRATION NUMBER

NCT00885118.

FUNDING

Nippon Boehringer Ingelheim Co., Ltd.

Responses of renal hemodynamics and tubular functions to acute sodium-glucose cotransporter 2 inhibitor administration in non-diabetic anesthetized rats

The aim of this study is to examine the effects of acute administration of luseogliflozin, the sodium–glucose cotransporter 2 (SGLT2) inhibitor, on renal hemodynamics and tubular functions in anesthetized non-diabetic Sprague Dawley (SD) rats and 5/6 nephrectomized (Nx) SD rats. Renal blood flow (RBF), mean arterial pressure (MAP), and heart rate (HR) were continuously measured and urine was collected directly from the left ureter. Intraperitoneal injection of luseogliflozin (0.9 mg kg⁻¹) did not change MAP, HR, RBF, or creatinine clearance (CrCl) in SD rats (n = 7). Luseogliflozin significantly increased urine volume, which was associated with significantly increased urinary glucose excretion rates (P < 0.001). Similarly, luseogliflozin significantly increased urinary sodium excretion (from 0.07 ± 0.01 µmol min⁻¹ at baseline to 0.76 ± 0.08 µmol min⁻¹ at 120 min; P < 0.001). Furthermore, luseogliflozin resulted in significantly increased urinary pH (P < 0.001) and decreased urinary osmolality and urea concentration (P < 0.001) in SD rats. Similarly, in Nx SD rats (n = 5–6), luseogliflozin significantly increased urine volume and urinary glucose excretion (P < 0.001) without altering MAP, HR, RBF, or CrCl. Luseogliflozin did not elicit any significant effects on the other urinary parameters in Nx SD rats. These data indicate that SGLT2 inhibitor elicits direct tubular effects in non-diabetic rats with normal renal functions.

Factors Affecting Canagliflozin-Induced Transient Urine Volume Increase in Patients with Type 2 Diabetes Mellitus

Introduction

Sodium glucose co-transporter 2 (SGLT2) inhibitors exhibit diuretic activity, which is a possible mechanism underlying the cardiovascular benefit of these inhibitors. However, the osmotic diuresis-induced increase in urine volume, and the risk of dehydration have been of concern with SGLT2 inhibitor treatment. This study aimed to investigate the mechanism underlying SGLT2 inhibitor canagliflozin-induced diuresis in Japanese type 2 diabetes mellitus (T2DM) patients.

Methods

Thirteen T2DM patients received a daily oral dose of 100 mg canagliflozin before breakfast for 6 days. Blood and urine samples were collected at predetermined time points. The primary endpoint was evaluation of correlations between changes from baseline in urine volume and factors that are known to affect urine volume and between actual urine volume and these factors.

Results

Canagliflozin transiently increased urine volume and urinary sodium excretion on Day 1 with a return to baseline levels thereafter. Canagliflozin administration increased urinary glucose excretion, which was sustained during repeated-dose administration. Plasma atrial natriuretic peptide (ANP) and N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels decreased, while plasma renin activity increased. On Day 1 of treatment, changes in sodium and potassium excretion were closely correlated with changes in urine output. A post hoc multiple regression analysis showed changes in sodium excretion and water intake as factors that affected urine volume change at Day 1. Furthermore, relative to that at baseline, canagliflozin decreased blood glucose throughout the day and increased plasma total GLP-1 after breakfast.

Conclusion

Canagliflozin induced transient sodium excretion and did not induce water intake at Day 1; hence, natriuresis rather than glucose-induced osmotic diuresis may be a major factor involved in the canagliflozin-induced transient increase in urine output. In addition, canagliflozin decreased plasma ANP and NT-proBNP levels and increased plasma renin activity, which may be a compensatory mechanism for sodium retention, leading to subsequent urine output recovery.

Clinical trial registration

UMIN000019462.

Funding

Mitsubishi Tanabe Pharma Corporation.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-016-0457-8) contains supplementary material, which is available to authorized users.

The effects of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on mineral metabolism and bone in patients with type 2 diabetes mellitus

BACKGROUND

Sodium glucose co-transporter 2 (SGLT2) inhibitors lower blood glucose levels in patients with type 2 diabetes mellitus (T2DM) by increasing urinary glucose excretion. This review provides a comprehensive summary of preclinical and clinical data on the effects of the SGLT2 inhibitor canagliflozin on mineral balance and bone.

METHODS

Published articles and internal study reports through November 2015 were included.

RESULTS

In clinical studies, canagliflozin was not associated with meaningful changes in serum or urine calcium, parathyroid hormone, or vitamin D. Canagliflozin was associated with increases in serum magnesium and phosphate without changes in their urinary excretion. Increases in serum collagen type-1 beta-carboxy-telopeptide (beta-CTX), a bone resorption marker, and osteocalcin, a bone formation marker, were observed with canagliflozin. Decreases in total hip bone mineral density (BMD) of up to 1.2% were seen with canagliflozin after 2 years; no changes in BMD were seen at other skeletal sites. Changes in total hip BMD and serum beta-CTX with canagliflozin correlated with decreases in body weight. In a clinical program-wide analysis, canagliflozin was associated with increased fracture risk that was driven by a higher incidence in the cardiovascular safety study (CANVAS), with no fracture imbalance seen in pooled data from other Phase 3 studies. The fracture imbalance occurred within 12 weeks after initiating treatment, most frequently in the distal portion of the upper and lower extremities.

CONCLUSIONS

Across clinical studies, canagliflozin did not meaningfully affect calcium homeostasis or hormones regulating calcium homeostasis. Increases in bone turnover markers and decreases in BMD at the total hip, but not at other sites, that correlated with weight loss were seen with canagliflozin. Canagliflozin was associated with a higher fracture incidence within 12 weeks, primarily in distal extremities. Data from ongoing canagliflozin studies will provide additional information on fracture risk.

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.