1,721,173 research outputs found

    Il sistema endocannabinoide e il controllo del metabolismo energetico: fisiologia e fisiopatologia

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    The ability of the endocannabinoid system to control appetite, food intake and energy balance has recently received great attention, particularly in the light of the different modes of action underlying these functions. The endocannabinoid system modulates rewarding properties of food by acting at specific mesolimbic areas in the brain. In the hypothalamus, CB1 receptor and endocannabinoids are integrated components of the networks controlling appetite and food intake. Interestingly, the endocannabinoid system has recently been shown to control several metabolic functions by acting on peripheral tissues, such as adipocytes, hepatocytes, the skeletal muscles and the endocrine pancreas. The relevance of the system is further strengthened by the notion that visceral obesity seems to be a condition in which an overactivation of the endocannabinoid system occurs, therefore drugs interfering with this overactivation by blocking CB1 receptor are considered as valuable candidates for the treatment of obesity and related cardiometabolic risk factors. © 2008 AIM Publishing Srl

    La terapia farmacologica dell'obesità

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    Obesity is reaching epidemic proportions worldwide and it is correlated with various comorbidities, among which the most relevant are diabetes mellitus, arterial hypertension, and cardiovascular diseases. Obesity management is a modern challenge because of the rapid evolution of unfavorable lifestyles and unfortunately there are no effective treatments applicable to the large majority of obese/overweight people. The current medical attitude is to treat the complications of obesity (e.g. dyslipidemia, hypertension, diabetes, and cardiovascular diseases). However, the potential of treating obesity is enormous, bearing in mind that a volitional weight loss of 10 kg is associated with important risk factor improvement: blood pressure -10 mmHg, total cholesterol -10%, LDL cholesterol -15%, triglycerides -30%, fasting glucose -50%, HDL cholesterol +8%. Drug treatment for obesity is an evolving branch of pharmacology, burdened by severe side effects and consequences of the early drugs, withdrawn from the market, and challenged by the lack of long-term data on the effect of medications on obesity-related morbidity and mortality, first of all cardiovascular diseases. In Europe three antiobesity drugs are currently licensed: sibutramine, orlistat, and rimonabant; important trials with clinical endpoints are ongoing for sibutramine and rimonabant. While waiting for their results, it is convenient to evaluate these drugs for their effects on body weight and cardiometabolic risk factors. Sibutramine is a centrally acting serotonin/noradrenaline reuptake inhibitor that mainly increases satiety. At the level of brown adipose tissue, sibutramine can also facilitate energy expenditure by increasing thermogenesis. The long-term studies (five) documented a mean differential weight reduction of 4.45 kg for sibutramine vs placebo. Considering the principal studies, attrition rate was 43%. This drug not only reduces body weight and waist circumference, but it decreases triglycerides and uric acid as well and it increases HDL cholesterol; in diabetics it improves glycated hemoglobin. Sibutramine has conflicting effects on blood pressure: in some studies there was a minimal decrease, in some others a modest increase. In all the studies this drug increased pulse rate. Sibutramine is not recommended in patients with uncontrolled hypertension, or in case of history of cardio- and cerebrovascular disease. Orlistat is a pancreatic lipase inhibitor that reduces fat absorption by partially blocking the hydrolysis of dietary triglycerides. A recent meta-analysis evaluated 22 studies lasting for at least 12 months, in obese patients with a mean body mass index of 36.7 kg/m2, where orlistat was associated with hypocaloric diet or behavioral interventions: the net average weight loss was 2.89 kg (confidence interval 2.27-3.51 kg). Considering the principal studies, attrition rate ranged from 33 to 57%. Orlistat significantly decreases waist circumference, blood pressure, total and LDL cholesterol, but has no effect on HDL and triglycerides. This drug significantly reduced the incidence of diabetes only in subjects with impaired glucose tolerance. The major adverse effects with orlistat are mainly gastrointestinal (fatty and oily stool, fecal urgency, oily spotting, fecal incontinence) and attenuate over time. Orlistat should be avoided in patients with chronic malabsorption and cholestasis. Rimonabant is a selective antagonist of cannabinoid type 1 receptor. This drug, by inhibiting the overactivation of the endocannabinoid system, produces anorectic stimuli at the central nervous level, but also has effects on the peripheral systems involved in metabolism control, such as liver, adipose tissue, skeletal muscles, endocrine pancreas, and gastrointestinal apparatus, influencing many processes partially unknown. An ample experimental program named RIO (Rimonabant In Obesity) involved about 6600 obese or overweight patients to identify the effects of rimonabant in weight loss and associated cardiometabolic abnormalities, over and beyond a caloric restriction of 600 kcal in the treatment and placebo arms. In the four double-blind RIO trials published (Rio-North America, RIO-Europe, RIO-Lipids, RIO-Diabetes), rimonabant 20 mg significantly (p < 0.001) reduced weight by 6.3-6.9 kg in the non-diabetic groups vs placebo (-1.5-1.8 kg), whereas in the diabetic subjects enrolled in RIO-Diabetes, weight loss was 5.3 vs 1.4 kg in the placebo group. Attrition rate at 1 year ranged between 40 and 50%, similar to the studies with sibutramine or orlistat. Similarly to weight loss, also waist circumference was significantly reduced by rimonabant. As for cardiometabolic parameters, rimonabant induced a significant increase in HDL cholesterol and a significant decrease in triglycerides. Even if no significant LDL reduction was achieved, the RIO-Lipids study showed a significant decrease in small dense LDL particles, more atherogenic, in rimonabant-treated subjects. Non-diabetic treated patients improved basal insulin and indirect indexes of insulin resistance, while in the RIO-Diabetes study, the only one including diabetics, glycated hemoglobin improved by 0.7% in the active treatment arm vs placebo. The effects on HDL cholesterol and glycated hemoglobin seem in a large percentage unrelated to weight loss. These effects have been confirmed by another trial, named SERENADE, evaluating the treatment in naive diabetic patients. Rimonabant is not recommended in patients with a history of depressive disorders or suicidal ideation and with uncontrolled psychiatric illness, and is contraindicated in patients with ongoing major depression or ongoing antidepressive treatment. In conclusion, despite an enormous advancement in basic research to understand the pathogenetic mechanisms at the base of obesity, the pharmacological research did not reach the therapeutic opportunities available for other chronic conditions, like hypertension and dyslipidemia. However, the few molecules available for clinical practice (sibutramine, orlistat, rimonabant) have shown, when properly used, to contribute to reduce body weight and undoubtedly improve cardiometabolic risk factors. With this preamble, according to current guidelines and pharmacoeconomic studies, patients who might benefit from antiobesity treatment are those with a body mass index ≥ 30 or 27-29.9 kg/m2 with major obesity-related comorbidities such as hypertension, diabetes, dyslipidemia, obstructive sleep apnea, and metabolic syndrome. © 2008 AIM Publishing Srl

    Semaglutide for Treating Obesity Induced by Craniopharyngioma Resection: A Successful Case Study

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    : Surgical treatment of craniopharyngioma often leads to a rapid and dramatic weight gain, leading to hypothalamic obesity. Treatment focused on the diet, physical activity, and different types of drugs have very often provided unsatisfactory results. To date, no data have been reported on hypothalamic obesity (HO) regarding the use of semaglutide, a novel type 1 receptor glucagon-like peptide-1 agonist, to limit body weight gain after surgical removal of a neoplasm, despite its already documented efficacy in obesity treatment. In this case report, we tested semaglutide in an 18-year-old patient with HO induced by a surgical intervention for craniopharyngioma. A very favorable treatment response was found in terms of body weight reduction and improvement in metabolic parameters. Our patient lost more than than 30 kg after only 6 months of therapy, which has never been reported before in the literature on HO

    Aldosterone and type 2 diabetes mellitus

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    Primary hyperaldosteronism (PA) has recently been demonstrated to be strictly associated to metabolic syndrome as compared with essential hypertension (EH). Besides, the characteristics of metabolic syndrome are different in PA compared to EH, as high fasting glucose is more frequent in the former condition. The adverse effect of excess aldosterone on insulin metabolic signaling has generated increasing interest in the role of hyperaldosteronism in the pathogenesis of insulin resistance and resistant hypertension. Moreover, aldosterone receptor antagonist therapy in diabetic and cardiopathic patients improved coronary flow. The aim of this review is to present recent knowledge about the relationship between aldosterone, insulin resistance and diabetes

    Cross-talk between adipose tissue and the HPA axis in obesity and overt hypercortisolemic states

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    In addition to its roles in providing insulation and mechanical support, adipose tissue (AT) has been recognised as the major site for storage of surplus fuel. Since leptin was discovered, white AT (WAT) has been recognised as an endocrine organ and an important source of biologically active substances with local and/or systemic action called adipokines. The metabolic and endocrine activities of AT are under the control of several hormones: a particular role has been played by glucocorticoids (GC), which able to participate, along with other hormones, both in recruitment of progenitor cells and in differentiation and secretive activities. AT is also able to generate cortisol from cortisone through 11β-hydroxysteroid-dehydrogenase (11β-HSD). There are controversial reports in the literature, showing a hyperactivity of 11β-HSD in obesity. It has been postulated that obesity, particularly the visceral body fat distribution (V-BFD), may be considered a maladaptation to stress exposure, thus leading to hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis, and higher-than-normal cortisol levels. In this review, we will examine the cross-talk between the HPA axis and AT, their relationship under stressful events, depending on steroid hormones and different adipokine secretions

    Comparative targeted metabolomic profiles of porcine plasma and serum

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    Metabolomics has been used to characterise many biological matrices and obtain detailed pictures of biological systems based on many metabolites. Plasma and serum are two blood-derived biofluids commonly used to assess and monitor the organismal metabolism and obtain information on the physiological and health conditions of an animal. Plasma is the supernatant that is separated from the cellular components after centrifugation of the blood that is first added with an anticoagulant. Serum is obtained after centrifugation of the blood that has been coagulated. The choice of one or the other biofluid for metabolomic analyses is related to specific analytical needs and technical issues, to problems derived by the collection and preparation steps, in particular when specimens are sampled from animals involved in field studies. Thus far, most of the metabolomic studies that compared plasma and serum have been carried out in humans and very little is known on the pigs. In this study, we used a targeted metabolomic platform that can detect about 180 metabolites of five biochemical classes to compare plasma and serum profiles of samples collected from 24 pigs. To also obtain a cross-species comparative metabolomic analysis, information for human plasma and serum derived from the same platform was retrieved from previous studies. Statistical analyses included univariate and multivariate approaches aimed at identifying stable and/or differentially abundant metabolites between the two porcine biofluids. A total of 154 (∼83%) metabolites passed the initial quality control, indicating a good repeatability of the analytical platform in pigs. Discarded metabolites included aspartate and biogenic amines that were already reported to be unstable in human studies. More than 80% of the metabolites had similar profiles in both porcine biofluids (average correlation was 0.75). Concentrations were usually higher in serum than in plasma, in agreement with what was already reported in humans. The univariate analysis identified 44 metabolites that had statistically different concentrations between porcine plasma and serum, of which 28 metabolites were also confirmed by the multivariate analysis. The obtained picture described similarities and differences between these two biofluids in pigs and the related human-pig comparisons. The obtained information can be useful for the choice of one or the other matrix for the implementation of metabolomic studies in this livestock species. The results can also provide useful hints to valuing the pig as animal model, in particular when metabolite-derived physiological states are relevant
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