SARS-CoV-2, a novel coronavirus found in Wuhan (China) at the end of 2019, is the etiological agent of the current pandemic that is a heterogeneous disease, named coronavirus disease 2019 (COVID-19). SARS-CoV-2 affects primarily the lungs, but it can induce multi-organ involvement such as acute myocardial injury, myocarditis, thromboembolic eventsandrenal failure. Hypertension, chronic kidney disease, diabetes mellitus and obesity increase the risk of severe complications of COVID-19. There is no certain explanation for this systemic COVID-19 involvement, but it could be related to endothelial dysfunction, due to direct (endothelial cells are infected by the virus) and indirect damage (systemic inflammation) factors. Angiotensin-converting enzyme 2 (ACE2), expressed in human endothelium, has a fundamental role in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In fact, ACE2 is used as a receptor by SARS-CoV-2, leading to the downregulation of these receptors on endothelial cells; once inside, this virus reduces the integrity of endothelial tissue, with exposure of prothrombotic molecules, platelet adhesion, activation of coagulation cascades and, consequently, vascular damage. Systemic microangiopathy and thromboembolism can lead to multi-organ failure with an elevated risk of death. Considering the crucial role of the immunological response and endothelial damage in developing the severe form of COVID-19, in this review, we will attempt to clarify the underlying pathophysiological mechanisms.

Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are two gut hormones, defined incretins, responsible for the amplification of insulin secretion after oral glucose intake. Unlike GLP-1, GIP has little acute effect on insulin secretion and no effect on food intake; instead it seems that the GIP may be an obesity-promoting hormone. In patients with type2 diabetes mellitus (T2DM) some studies found a downregulation of GIP receptors on pancreatic β cells caused by hyperglycemic state, but the glucagonotropic effect persisted. Agonists of the receptor for the GLP-1 have proven successful for the treatment of diabetes, since they reduce the risk for cardiovascular and renal events, but the possible application of GIP as therapy for T2DM is discussed. Moreover, the latest evidence showed a synergetic effect when GIP was combined with GLP-1 in monomolecular co-agonists. In fact, compared with the separate infusion of each hormone, the combination increased both insulin response and glucagonostatic response. In accordance with theseconsiderations, a dual GIP/GLP-1receptor agonist, i.e., Tirzepatide, known as a “twincretin” had been developed. In the pre-clinical trials, as well as Phase 1–3 clinical trials, Tirzepatideshowedpotent glucose lowering and weight loss effects within an acceptable safety.

Aims: Diastolic dysfunction represents the earliest and most common manifestation of diabetic cardiomyopathy. Nitric oxide (NO), a potent vasodilator and anti-inflammatory mediator released from the subendocardial and coronary endothelium, favors left ventricular distensibility and relaxation. In type 2 diabetes (T2D), the NO bioavailability is reduced due to the oxidative stress and inflammatory state of the endothelium, because of chronic hyperglycemia. The aim of the present research is to evaluate the relationship between endothelial function and diastolic function in subjects with T2D. Method: Subjects with T2D and age and sex-matched healthy controls were consecutively recruited. All participants underwent flow-mediated dilation (FMD) to assess endothelial function, and echocardiography to evaluate diastolic function. Results: Thirty-five patients (6 women, 29 men) and 35 healthy controls were included in the final analysis. FMD was significantly lower in T2D than controls (4.4 ± 3.4 vs. 8.5 ± 4.3%, p = 0.001). T2D presented different abnormalities in diastolic function compared to controls: lower E/A (early to late diastolic transmitral flow velocity), lower septal and lateral e′ (early diastolic myocardial tissue velocity at septum and lateral wall), and higher E/e′ (surrogate of filling pressure). In subjects with T2D, we observed a significant correlation between FMD and E/e′ (r = −0.63, p = 0.001), lateral e′ (r = 0.44, p = 0.03), and septal e′ (r = 0.39, p = 0.05). Conclusions: Our observational study demonstrated a link between FMD and diastolic dysfunction in subjects with type 2 diabetes.

Background: Obesity impairs renal function through direct mechanisms, such as proinflammatory adipocytokine production, and indirect mechanisms, including obesity-related comorbidities. Despite the increasing prevalence of obesity and chronic kidney disease (CKD), clinical guidelines for their combined management remain lacking. Very Low Energy Ketogenic Therapy (VLEKT) has demonstrated efficacy in weight loss, but evidence on its safety and efficacy in individuals with obesity and mild renal impairment is limited. This study aimed to assess the efficacy and safety of Phase 1 of VLEKT in individuals with obesity and mild renal impairment. Methods: This cross-sectional study included 73 individuals with overweight or obesity (mean age 53.7 ± 8.8 years; BMI 35.3 ± 4.2 kg/m²) and an estimated glomerular filtration rate (eGFR) of at least 60 mL/min/1.73 m² (evaluated using the CKD-EPI equation). Anthropometric (weight, BMI, and waist circumference) and biochemical parameters (fasting plasma glucose, insulin, cholesterol profile, triglycerides, AST, ALT, and urea) were collected at baseline and after 45 (±2) days of Phase 1 of VLEKT. Results: At baseline, 54.8% of participants had an eGFR <90 mL/min/1.73 m², while 45.2% had an eGFR ≥ 90 mL/min/1.73 m², with no significant differences in sex distribution. After 45 (±2) days of Phase 1 of VLEKT, both groups showed significant reductions in BMI (p < 0.001), waist circumference (p < 0.001), fasting plasma glucose (p ≤ 0.004), insulin (p < 0.001), HOMA-IR (p < 0.001), total cholesterol (p < 0.001), LDL cholesterol (p < 0.001), LDL/HDL ratio (p ≤ 0.002), triglycerides (p ≤ 0.009), AST (p ≤ 0.034), and ALT (p ≤ 0.009). Notably, the eGFR significantly increased in participants with an eGFR < 90 mL/min/1.73 m² (p < 0.001), while no changes were observed in those with an eGFR ≥ 90 mL/min/1.73 m². Conclusions: Phase 1 of VLEKT could effectively promote weight loss and metabolic improvements without compromising renal function, even in individuals with obesity and mild renal impairment. Further research is warranted to confirm the efficacy and safety of VLEKT and to assess outcomes across all protocol phases.