Obesity-related changes in the vascular actions of insulin

Abstract Over the past 2 to 3 decades, research has focused on the changes in the vascular effects of insulin occurring in insulin resistant states like obesity. Consistent evidence indicates that obesity results in reduced endothelial release of nitric oxide in response to insulin, associated with concomitant enhancement in the production of endothelin-1. More recent work has pointed toward reduced vascular permeability and changes in the physical-chemical characteristics of the perivascular extracellular matrix as additional mechanisms of impaired insulin sensitivity in obesity. All these perturbations are important, because they contribute to impaired delivery of insulin itself and metabolic substrates to the target tissues and may play a role in the development of both diabetes and vascular damage. This review will describe the physiological vascular actions of insulin and their changes in obesity, focusing on some established pathophysiological determinants of the derangement of vascular insulin signaling, such as the lipid overflow from expanded fat depots and signals originating from inflamed obese adipose tissue (both distant and perivascular). Also, it will outline novel evidence underscoring the contribution of dysregulated adipokine secretion and changes in intestinal permeability and gut microbiome. Finally, it will touch upon some unresolved issues, such as the potential role of vascular insulin resistance in obesity-driven adipose tissue remodeling, and will discuss perspectives for future studies, regarding in particular possible therapeutic strategies with translational implications for the patients care

Endothelin-dependent vasoconstrictor activity in metabolically healthy and unhealthy obese patients

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Metabolic and Cardiovascular Effects of Ghrelin

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, is synthesized as a preprohormone and then proteolytically processed to yield a 28-amino acid peptide. This peptide was originally reported to induce growth hormone release; large evidence, however, has indicated many other physiological activities of ghrelin, including regulation of food intake and energy balance, as well as of lipid and glucose metabolism. Ghrelin receptors have been detected in the hypothalamus and the pituitary, but also in the cardiovascular system, where ghrelin exerts beneficial hemodynamic activities. Ghrelin administration acutely improves endothelial dysfunction by increasing nitric oxide bioavailability and normalizes the altered balance between endothelin-1 and nitric oxide within the vasculature of patients with metabolic syndrome. Other cardiovascular effects of ghrelin include improvement of left ventricular contractility and cardiac output, as well as reduction of arterial pressure and systemic vascular resistance. In addition, antinflammatory and antiapoptotic actions of ghrelin have been reported both in vivo and in vitro. This review summarizes the most recent findings on the metabolic and cardiovascular effects of ghrelin through GH-dependent and -independent mechanisms and the possible role of ghrelin as a therapeutic molecule for treating cardiovascular diseases

Mirabegron relaxes arteries from human visceral adipose tissue through antagonism of α1-adrenergic receptors

Aim: As inadequate perfusion has emerged as a key determinant of adipose tissue dysfunction in obesity, interest has grown regarding possible pharmacological interventions to prevent this process. Mirabegron has proved to improve insulin sensitivity and glucose homeostasis in obese humans via stimulation of β3-adrenoceptors which also seem to mediate endothelium-dependent vasodilation in disparate human vascular beds. We characterized, therefore, the vasomotor function of mirabegron in human adipose tissue arteries and the underlying mechanisms. Methods: Small arteries (116-734 μm) isolated from visceral adipose tissue were studied ex vivo in a wire myograph. After vessels had been contracted, changes in vascular tone in response to mirabegron were determined under different conditions. Results: Mirabegron did not elicit vasorelaxation in vessels contracted with U46619 or high-K+ (both P > 0.05). Notably, mirabegron markedly blunted the contractile effect of the α1-adrenergic receptor agonist phenylephrine (P < 0.001) either in presence or absence of the vascular endothelium. The anti-contractile action of mirabegron on phenylephrine-induced vasoconstriction was not influenced by the presence of the selective β3-adrenoceptor blocker L-748,337 (P < 0.05); lack of involvement of β3-adrenoceptors was further supported by absent vascular staining for them at immunohistochemistry. Conclusions: Mirabegron induces endothelium-independent vasorelaxation in arteries from visceral adipose tissue, likely through antagonism of α1-adrenoceptors

Differences in the vascular and metabolic profiles between metabolically healthy and unhealthy obesity

Abstract Individuals suffering from severe obesity but not presenting the typical metabolic alterations, are included in a subclass of obesity defined Metabolically Healthy Obesity (MHO). The physiological factors underlying what seems a protective and favourable metabolic profile remain unclear. MHO individuals are more insulin-sensitive, have relatively lower visceral/ectopic fat accumulation and reduced levels of chronic low-grade inflammation, compared to obese subjects with co-morbidities. The study of MHO subjects represents a great opportunity for the recognition of the mechanisms that lead to the vascular and metabolic complications in obesity. Finding the differences among the metabolic profile of visceral adipose tissue between metabolically healthy and unhealthy obesity may lead to future personalized and stratified therapies.This review article summarizes the pathomechanisms and metabolic changes in MHO and metabolically unhealthy obesity (MUO), reviews clinical studies on the subject, and discusses preventive and therapeutic options

Mesothelioma in Familial Mediterranean Fever With Colchicine Intolerance: A Case Report and Literature Review

A 65-year-old Italian physician affected by Familial Mediterranean fever (FMF) was hospitalized due to progressive abdominal enlargement, which had begun 6 months before admission. Physical examination revealed ascites and bilateral leg edema. Abdominal CT scan showed ascitic fluid and extensive multiple peritoneal implants; peritoneal CT-guided biopsy revealed an epithelial-type malignant mesothelioma. The patient\u2019s past medical history revealed recurrent episodes of abdominal pain and fever from the age of 2. Clinical diagnosis of FMF was suspected at the age of 25, while genetic analysis, performed at the age of 50, confirmed homozygosity for the M694I mutation in the MEFV gene. Treatment with the first line FMF drug colchicine was started and stopped several times because of worsened leukopenia. The patient in fact had a history of asymptomatic leukopenia/lymphopenia from an early age; the intake of colchicine aggravated his pre-existing problem until the definitive suspension of the drug. As for second-line drugs, canakinumab was first prescribed, but due to prescription issues, it was not possible to be administered. When he was given anakinra, there was a worsening of leukopenia leading to septic fever. Systematic literature review indicates that, in most cases, recurrent peritoneal inflammation results in benign peritoneal fibrosis or less commonly in encapsulating peritonitis. There are only a few reported cases of recurrent peritoneal inflammation progressing from FMF to peritoneal mesothelioma (MST). In such cases, intolerance to colchicine or its erratic intake may lead to long-term recurrent inflammation, which usually precedes the development of the tumor, while pre-existing leukopenia, as in our patient, could also be a factor promoting or accelerating the tumor progression. In conclusion, we suggest that in the presence of intolerance or resistance to colchicine, interleukin (IL)-1 inhibition could suppress peritoneal inflammation and prevent MSTs

Sunitinib in patients with pre-treated pancreatic neuroendocrine tumors: A real-world study

Introduction: Besides data reported in a Phase-III trial, data on sunitinib in pancreatic Neuroendocrine Tumors (panNETs) are scanty. Aim: To evaluate sunitinib efficacy and tolerability in panNETs patients treated in a real-world setting. Patients and methods: Retrospective analysis of progressive panNETs treated with sunitinib. Efficacy was assessed by evaluating progression-free survival, overall survival, and disease control (DC) rate (stable disease (SD) + partial response + complete response). Data are reported as median (25th\ue2\u80\u9375th IQR). Results: Eighty patients were included. Overall, 71.1% had NET G2, 26.3% had NET G1, and 2.6% had NET G3 neoplasms. A total of 53 patients (66.3%) had received three or more therapeutic regimens before sunitinib, with 24 patients (30%) having been treated with four previous treatments. Median PFS was 10 months. Similar risk of progression was observed between NET G1 and NET G2 tumors (median PFS 11 months and 8 months, respectively), and between patients who had received \ue2\u89\ua5 3 vs \ue2\u89\ua4 2 therapeutic approaches before sunitinib (median PFS 9 months and 10 months, respectively). DC rate was 71.3% and SD was the most frequent observed response, occurring in 43 pts (53.8%). Overall, 59 pts (73.8%) experienced AEs, which were grade 1\ue2\u80\u932 in 43 of them (72.9%), grade 3 in 15 pts (25.4%), and grade 4 in one patient (1.7%). Six pts (7.5%) stopped treatment due to toxicity. Conclusions: The present real-world experience shows that sunitinib is a safe and effective treatment for panNETs, even in the clinical setting of heavily pre-treated, progressive diseases

INfluenza Vaccine Indication During therapy with Immune checkpoint inhibitors: a transversal challenge. The INVIDIa study

Aim: Considering the unmet need for the counseling of cancer patients treated with immune checkpoint inhibitors (CKI) about influenza vaccination, an explorative study was planned to assess flu vaccine efficacy in this population. Methods: INVIDIa was a retrospective, multicenter study, enrolling consecutive advanced cancer outpatients receiving CKI during the influenza season 2016-2017. Results: Of 300 patients, 79 received flu vaccine. The incidence of influenza syndrome was 24.1% among vaccinated, versus 11.8% of controls; odds ratio: 2.4; 95% CI: 1.23-4.59; p = 0.009. The clinical ineffectiveness of vaccine was more pronounced among elderly: 37.8% among vaccinated patients, versus 6.1% of unvaccinated, odds ratio: 9.28; 95% CI: 2.77-31.14; p < 0.0001. Conclusion: Although influenza vaccine may be clinically ineffective in advanced cancer patients receiving CKI, it seems not to negatively impact the efficacy of anticancer therapy

Variable Changes of Circulating ANGPTL3 and ANGPTL4 in Different Obese Phenotypes: Relationship with Vasodilator Dysfunction

Obesity associates with premature atherosclerosis and an increased burden of cardiovascular disease, especially when accompanied by abnormalities of lipid and glucose metabolism. Angiopoietin-like (ANGPTL)3 and ANGPTL4 are metabolic regulators, whose upregulation is associated with dyslipidemia, insulin resistance and atherosclerosis. We analyzed, therefore, changes in circulating ANGPTL3 and ANGPTL4 in obese patients with different metabolic phenotypes and their relation with impaired vasodilator reactivity, an early abnormality in atherosclerosis. Compared to the lean subjects (n = 42), circulating ANGPTL3 was elevated (both p > 0.001) in the patients with metabolically unhealthy obesity (MUO; n = 87) and type 2 diabetes (T2D; n = 31), but not in those with metabolically healthy obesity (MHO; n = 48, p > 0.05). Circulating ANGPTL4, by contrast, was increased in all obese subgroups (all p < 0.001 vs. lean subjects). Vasodilator responses to both acetylcholine and sodium nitroprusside were reduced in the three obese subgroups vs. lean subjects (all p < 0.001), with greater impairment in the patients with T2D than in those with MHO and MUO (all p < 0.05). In the whole population, an inverse relationship (r = 0.27; p = 0.003) was observed between circulating ANGPTL4 and endothelium-dependent vasorelaxation. Circulating ANGPTL3 and ANGPTL4 undergo variable changes in obese patients with different metabolic phenotypes; changes in ANGPTL4 relate to endothelial dysfunction, making this protein a possible target for vascular prevention in these patients