First-dose effect of the SGLT2 inhibitor ipragliflozin on cardiovascular activity in spontaneously diabetic Torii fatty rats

SGLT2 Inhibitors in Diabetic Patients With Cardiovascular Disease or at High Cardiovascular Risk: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

To investigate the effect of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with diabetes with cardiovascular disease (CVD) or at high cardiovascular risk.

Design

Systematic review and meta-analysis of randomized controlled trials (RCTs).

Data sources

Pubmed, Embase, the Cochrane Library, and ClinicalTrial.gov from their inception to August 28, 2021.

Review methods

Randomized control trials (RCTs) assess the effects of SGLT2i in patients with diabetes with cardiovascular disease or at high cardiovascular risk. Primary outcomes included the composite outcome of cardiovascular death (CV death) and hospitalization for heart failure (HHF), HHF, and renal composite outcomes. Secondary outcomes included major adverse cardiovascular events (MACE), CV death, all-cause mortality, and change from the baseline in HbA1c. Additionally, we assessed the effects of treatment in prespecified subgroups on the combined risk of primary and secondary outcomes. These subgroups were based on history of heart failure (HF), estimated glomerular filtration rate (eGFR) levels, and history of hypertension (HTN). A meta-analysis was carried out by using fixed effect models to calculate hazard ratio (HR) or mean difference (MD) between the SGLT2i administrated groups and the control groups.

Results

Four major studies (n = 42,568) were included. Primary outcomes showed that SGLT2i was associated with significantly lower risk of CV death/HHF (HR, 0.90; 95% confidence interval, 0.84 to 0.98; P for heterogeneity = 0.01), HHF (HR, 0.84; 95% CI, 0.73 to 0.98; p = 0.02), and renal composite outcomes (HR, 0.83; 95%CI, 0.74 to 0.92; p = 0.0007) in patients with diabetes with CVD or at high CV risk. Secondary outcome showed that the use of SGLT2i was associated with significant reduction of the HbA1c level (MD, −0.30; 95% CI, −0.36 to −0.23; p < 0.00001). In subgroup analyses, SGLT2i significantly reduced the risk of renal composite outcomes in patients without history of HF (HR, 0.75; 95% CI, 0.62 to 0.91; p = 0.003 < 0.025). No statistically significant differences were observed in other secondary outcomes and subgroup analyses.

Conclusions

The SGLT2i showed benefits on CV death/HHF, HHF, renal composite outcomes, and HbA1c reduction in patients with diabetes with CVD or at high CV risk. The benefits of improving renal composite outcomes were observed only in patients with diabetes without HF history.

Systematic Review Registration

PROSPERO CRD42021227400

Phlorizin attenuates visceral hypersensitivity and colonic hyperpermeability in a rat model of irritable bowel syndrome

Visceral hypersensitivity and impaired gut barrier are crucial contributors to the pathophysiology of irritable bowel syndrome (IBS), and those are mediated via corticotropin-releasing factor (CRF)-Toll like receptor 4-pro-inflammatory cytokine signaling. Phlorizin is an inhibitor of sodium-linked glucose transporters (SGLTs), and known to have anti-cytokine properties. Thus, we hypothesized that phlorizin may improve these gastrointestinal changes in IBS, and tested this hypothesis in rat IBS models, i.e., lipopolysaccharide (LPS) or CRF-induced visceral hypersensitivity and colonic hyperpermeability. The visceral pain threshold in response to colonic balloon distention was estimated by abdominal muscle contractions by electromyogram, and colonic permeability was measured by quantifying the absorbed Evans blue in colonic tissue. Subcutaneous (s.c.) injection of phlorizin inhibited visceral hypersensitivity and colonic hyperpermeability induced by LPS in a dose-dependent manner. Phlorizin also blocked CRF-induced these gastrointestinal changes. Phlorizin is known to inhibit both SGLT1 and SGLT2, but intragastric administration of phlorizin may only inhibit SGLT1 because gut mainly expresses SGLT1. We found that intragastric phlorizin did not display any effects, but ipragliflozin, an orally active and selective SGLT2 inhibitor improved the gastrointestinal changes in the LPS model. Compound C, an adenosine monophosphate-activated protein kinase (AMPK) inhibitor, N^G-nitro-L-arginine methyl ester, a nitric oxide (NO) synthesis inhibitor and naloxone, an opioid receptor antagonist reversed the effects of phlorizin. In conclusions, phlorizin improved visceral hypersensitivity and colonic hyperpermeability in IBS models. These effects may result from inhibition of SGLT2, and were mediated via AMPK, NO and opioid pathways. Phlorizin may be effective for the treatment of IBS.

Empagliflozin, a sodium glucose co-transporter-2 inhibitor, alleviates atrial remodeling and improves mitochondrial function in high-fat diet/streptozotocin-induced diabetic rats

Background

Diabetes mellitus is an important risk factor for atrial fibrillation (AF) development. Sodium–glucose co-transporter-2 (SGLT-2) inhibitors are used for the treatment of type 2 diabetes mellitus (T2DM). Their cardioprotective effects have been reported but whether they prevent AF in T2DM patients are less well-explored. We tested the hypothesis that the SGLT-2 inhibitor, empagliflozin, can prevent atrial remodeling in a diabetic rat model.

Methods

High-fat diet and low-dose streptozotocin (STZ) treatment were used to induce T2DM. A total of 96 rats were randomized into the following four groups: (i) control (ii) T2DM, (iii) low-dose empagliflozin (10 mg/kg/day)/T2DM; and (iv) high-dose empagliflozin (30 mg/kg/day)/T2DM by the intragastric route for 8 weeks.

Results

Compared with the control group, left atrial diameter, interstitial fibrosis and the incidence of AF inducibility were significantly increased in the DM group. Moreover, atrial mitochondrial respiratory function, mitochondrial membrane potential, and mitochondrial biogenesis were impaired. Empagliflozin treatment significantly prevented the development of these abnormalities in DM rats, likely via the peroxisome proliferator-activated receptor-c coactivator 1α (PGC-1α)/nuclear respiratory factor-1 (NRF-1)/mitochondrial transcription factor A (Tfam) signaling pathway.

Conclusions

Empagliflozin can ameliorate atrial structural and electrical remodeling as well as improve mitochondrial function and mitochondrial biogenesis in T2DM, hence may be potentially used in the prevention of T2DM-related atrial fibrillation.