Effects of Dapagliflozin on Endothelial Function, Renal Injury Markers, and Glycemic Control in Drug-Naïve Patients with Type 2 Diabetes Mellitus

Endothelial Dysfunction and Heart Failure with Preserved Ejection Fraction-An Updated Review of the Literature

Heart failure (HF) is a clinical syndrome consisting of typical symptoms and signs due to structural and/or functional abnormalities of the heart, resulting in elevated intracardiac pressures and/or inadequate cardiac output. The vascular system plays a crucial role in the development and progression of HF regardless of ejection fraction, with endothelial dysfunction (ED) as one of the principal features of HF. The main ED manifestations (i.e., impaired endothelium-dependent vasodilation, increased oxidative stress, chronic inflammation, leukocyte adhesion, and endothelial cell senescence) affect the systemic and pulmonary haemodynamic and the renal and coronary circulation. The present review is aimed to discuss the contribution of ED to HF pathophysiology-in particular, HF with preserved ejection fraction-ED role in HF patients, and the possible effects of pharmacological and non-pharmacological approaches. For this purpose, relevant data from a literature search (PubMed, Scopus, EMBASE, and Medline) were reviewed. As a result, ED, assessed via venous occlusion plethysmography or flow-mediated dilation, was shown to be independently associated with poor outcomes in HF patients (e.g., mortality, cardiovascular events, and hospitalization due to worsening HF). In addition, SGLT2 inhibitors, endothelin antagonists, endothelial nitric oxide synthase cofactors, antioxidants, and exercise training were shown to positively modulate ED in HF. Despite the need for future research to better clarify the role of the vascular endothelium in HF, ED represents an interesting and promising potential therapeutic target.

Novel use of structural equation modelling to examine diet and metabolic traits associated with microvascular endothelial dysfunction in middle-aged Chinese males: a cross-sectional study

BACKGROUND

The present study aims to use structural equation modelling (SEM) with multiple regression pathways to examine direct and indirect links from diet and metabolic traits to microvascular endothelial dysfunction (ED) among middle-aged Chinese males.

METHODS

The study was conducted in middle-aged Chinese males, who underwent a health check-up between 2018 and 2019. Data on lifestyle behaviour factors (physical activity, diet pattern, sleep quality and diet data underwent factor analysis in advance) and metabolic risk factors referring to metabolic traits were introduced into the SEM to examine inter-relationship among these factors and their association with ED, as evaluated by the reactive hyperaemia index (RHI).

RESULTS

Both exploratory factor analysis and confirmatory factor analysis identified two major dietary patterns: 'prudent pattern' and 'western pattern'. The univariate test suggested that only triglycerides (TGs) and prudent dietary pattern were directly associated with RHI. Furthermore, prudent dietary pattern had an indirect association with RHI via TG (prudent diet→TG: β=-0.15, p<0.05; TG→RHI: β=-0.17, p<0.001). As to confirming the hypothesised association between variables apart, physical activity frequency was correlated to the decrease in TG (β=-0.29, p<0.001), but had no direct correlation to RHI.

CONCLUSION

The network of direct and indirect associations among diet pattern and cardiometabolic risk factors with RHI measured ED among middle-aged males. The most significant modifiable factors identified were TG and prudent diet pattern, which needs to be targeted as preventive strategies for early microvascular impairment.

Dapagliflozin protects the kidney in a non-diabetic model of cardiorenal syndrome

Cardiorenal syndrome encompasses a spectrum of disorders involving heart and kidney dysfunction, and sharing common risk factors, such as hypertension and diabetes. Clinical studies have shown that patients with and without diabetes may benefit from using sodium-glucose cotransporter 2 inhibitors to reduce the risk of heart failure and ameliorate renal endpoints. Because the underlying mechanisms remain elusive, we investigated the effects of dapagliflozin on the progression of renal damage, using a model of non-diabetic cardiorenal disease. Dahl salt-sensitive rats were fed a high-salt diet for five weeks and then randomized to dapagliflozin or vehicle for the following six weeks. After treatment with dapagliflozin, renal function resulted ameliorated as shown by decrease of albuminuria and urine albumin-to-creatinine ratio. Functional benefit was accompanied by a decreased accumulation of extracellular matrix and a reduced number of sclerotic glomeruli. Dapagliflozin significantly reduced expression of inflammatory and endothelial activation markers such as NF-κB and e-selectin. Upregulation of pro-oxidant-releasing NADPH oxidases 2 and 4 as well as downregulation of antioxidant enzymes were also counteracted by drug treatment. Our findings also evidenced the modulation of both classic and non-classic renin-angiotensin-aldosterone system (RAAS), and effects of dapagliflozin on gene expression of ion channels/transporters involved in renal homeostasis. Thus, in a non-diabetic model of cardiorenal syndrome, dapagliflozin provides renal protection by modulating inflammatory response, endothelial activation, fibrosis, oxidative stress, local RAAS and ion channels.

Association of Circulating Ketone Bodies With Functional Outcomes After ST-Segment Elevation Myocardial Infarction

BACKGROUND

Circulating ketone bodies (KBs) are increased in patients with heart failure (HF), corresponding with increased cardiac KB metabolism and HF severity. However, the role of circulating KBs in ischemia/reperfusion remains unknown.

OBJECTIVES

This study sought to investigate longitudinal changes of KBs and their associations with functional outcomes in patients presenting with ST-segment elevation myocardial infarction (STEMI).

METHODS

KBs were measured in 369 participants from a randomized trial on early metformin therapy after STEMI. Nonfasting plasma concentrations of KBs (β-hydroxybutyrate, acetoacetate, and acetone) were measured by nuclear magnetic resonance spectroscopy at presentation, at 24 hours, and after 4 months. Myocardial infarct size and left ventricular ejection fraction (LVEF) were determined by cardiac magnetic resonance imaging at 4 months. Associations of circulating KBs with infarct size and LVEF were determined using multivariable linear regression analyses.

RESULTS

Circulating KBs were high at presentation with STEMI (median total KBs: 520 μmol/L; interquartile range [IQR]: 315-997 μmol/L). At 24 hours after reperfusion, KBs were still high compared with levels at 4-month follow-up (206 μmol/L [IQR: 174-246] vs 166 μmol/L [IQR: 143-201], respectively; P < 0.001). Increased KB concentrations at 24 hours were independently associated with larger myocardial infarct size (total KBs, per 100 μmol/L: β = 1.56; 95% confidence interval: 0.29-2.83; P = 0.016) and lower LVEF (β = -1.78; 95% CI: (-3.17 to -0.39; P = 0.012).

CONCLUSIONS

Circulating KBs are increased in patients presenting with STEMI. Higher KBs at 24 hours are associated with functional outcomes after STEMI, which suggests a potential role for ketone metabolism in response to myocardial ischemia. (Metabolic Modulation With Metformin to Reduce Heart Failure After Acute Myocardial Infarction: Glycometabolic Intervention as Adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III): a Randomized Controlled Trial; NCT01217307).

Effects of SGLT2 Inhibitors on Ion Homeostasis and Oxidative Stress associated Mechanisms in Heart Failure

Sodium-glucose cotransporter 2 (SGLT2) inhibitors present a class of antidiabetic drugs, which inhibit renal glucose reabsorption resulting in the elevation of urinary glucose levels. Within the past years, SGLT2 inhibitors have become increasingly relevant due to their effects beyond glycemic control in patients with type 2 diabetes (T2DM). Although dedicated large trials demonstrated cardioprotective effects of SGLT2 inhibitors, the exact mechanisms responsible for those benefits have not been fully identified. Alterations in Ca²⁺ signaling and oxidative stress accompanied by excessive reactive oxygen species (ROS) production, fibrosis and inflammatory processes form cornerstones of potential molecular targets for SGLT2 inhibitors. This review focused on three hypotheses for SGLT2 inhibitor-mediated cardioprotection: ion homeostasis, oxidative stress and endothelial dysfunction.

Dapagliflozin increases the lean-to total mass ratio in type 2 diabetes mellitus

We compared the effect of dapagliflozin versus glibenclamide on the ratio of lean-to total mass in patients with type 2 diabetes mellitus, carotid subclinical atherosclerosis, HbA1c 7.0-9.0% and 40-70 years-old. Ninety-eight patients (61% male; mean age 57 ± 7 years) were randomized into dapagliflozin 10 mg/day or glibenclamide 5 mg/day on top of metformin. Body composition was measured by Dual Energy X-Ray at randomization and after 12 weeks of treatment. Glycemic control was equivalent in both groups. Dapagliflozin decreased total body mass (-2741 g [95% CI: -3360 to 1945]; p < 0.001) and lean mass (-347 g [95% CI: -761 to -106]; p < 0.001), while glibenclamide increased total body mass (1060 g [95% CI: 140 to 1836]; p < 0.001) and lean mass (929 g [95% CI: 575 to 1283]; p < 0.001) for the differences between arms. The lean-to-total mass ratio increased by 1.2% in the dapagliflozin group and 0,018% in the glibenclamide group (p < 0.001). Dapagliflozin reduced the risk of a negative balance in the lean-to total mass ratio [OR: 0.16 (95% CI: 0.05 to 0.45); p < 0.001] even after adjustment for baseline lean-to total mass ratio, waist circumference, HOMAIR, HbA1c, mean of the two hands handgrip strength and gait speed [OR: 0.13 (95% CI: 0.03-0.57); p < 0.007]. In conclusion, under equivalent glycemic control, dapagliflozin reduced total body mass but increased the ratio of lean-to-total mass when compared with glibenclamide.

Prognostic value of arterial stiffness measurements in cardiovascular disease, diabetes, and its complications: The potential role of sodium-glucose co-transporter-2 inhibitors

Type 2 diabetes mellitus (T2DM) constitutes a global pandemic, representing the 7th cause of death worldwide. Morbidity and mortality of patients with T2DM are gradually increasing, while prevalence of cardiovascular disease (CVD) among these patients is almost 14% greater compared to the general population. Arterial stiffness is nowadays a valuable biomarker of CVD and a promising treatment target in specific patient groups, including those suffering from T2DM. Despite that fact, design of the available studies cannot prove causal relationship. Recently, a new antidiabetic drug class, namely sodium-glucose co-transporter-2 (SGLT-2) inhibitors, has attracted scientific interest, due to their multiple, beneficial, pleiotropic effects, especially those focused on CVD. There is limited relevant literature concerning the effects of SGLT-2 inhibitors on arterial stiffness, while retrieved results might be considered as conflicting. The aim of the present review article is to summarize acquired knowledge regarding the prognostic role of arterial stiffness in T2DM, along with the presentation of retrieved data on the potential role of SGLT-2 inhibitors.

Rationale for the Early Use of Sodium-Glucose Cotransporter-2 Inhibitors in Patients with Type 2 Diabetes

Diabetes-related complications including cardiovascular disease, heart failure (HF), chronic kidney disease, retinopathy, and neuropathy are associated with a high burden of disease. Early initiation of glucose-lowering therapy in patients with type 2 diabetes to achieve glycemic control is important for reduction of not only microvascular risk but also of CV (cardiovascular) risk. Clinical studies have indicated that early achievement of glycemic targets is likely to have the greatest effect on preventing microvascular and macrovascular complications. In addition to improvements in glycemic control and CV risk factors, CV outcomes trials (CVOTs) of empagliflozin (EMPA-REG OUTCOME), canagliflozin (CANVAS), and dapagliflozin (DECLARE-TIMI 58) showed significant glucose-independent reductions in the risk of major adverse CV events and/or hospitalization for HF, as well as reductions in the risk of kidney disease progression, versus placebo. These CVOTs and a renal outcomes study of canagliflozin (CREDENCE) support the early initiation of sodium-glucose cotransporter (SGLT)-2 inhibitors to potentially provide the most benefit toward glycemic control and CV and renal risk. Thus, current treatment recommendations include the early addition of SGLT-2 inhibitor therapy, not only in patients with established CVD, HF, and/or CKD but also in the general population of patients with T2D.Funding: AstraZeneca.