OBESITY AND METABOLIC SYNDROME: PLASMA LIPOPROTEINS ALTERATIONS

Obesity, especially if associated with metabolic syndrome, promotes oxidative stress, a low grade chronic inflammatory state, and modify the composition and function of plasma lipoproteins. Oxidative damage to lipoproteins not only make LDL atherogenic but can also alter HDL reducing their anti-atherogenic properties. The possibility of monitoring the lipid peroxidation of the individual regions of LDL and HDL could lead to more detailed information on the molecular mechanisms that are the basis of the increased risk of cardiovascular diseases observed in obesity and metabolic syndrome. The object of this study was to investigate the susceptibility to peroxidation of plasma and of the hydrophobic core and the surrounding envelope of LDL and HDL in obese male (BMI between 25 and 35 Kg mq) with (SM, n=20)) or without (OB, n =40) metabolic syndrome. The susceptibility of plasma to peroxidation was higher in SM and OB than in normo-weight controls (CT, n=60), but not significant differences were observed between these two obese groups. Also the susceptibility to peroxidation of isolated LDL and HDL was higher in both obese groups than in CT. LDL and HDL in SM presented an higher content of triacylglicerols than the corresponding HDL of OB. Moreover, the hydrophobic core of HDL showed a risk of peroxidation significantly higher in SM than in OB. This last parameter was inversely correlated with the waist to hip ratio, an index of visceral obesity. This last evidence seems to indicate that the increase of inflammation typical of the visceral adipose tissue could be one of the major causes of the higher susceptibility to peroxidation found in the hydrophobic core of HDL. The evaluation of the susceptibility to peroxidation of the core and the envelope of LDL and HDL might contribute to the identification of a subset of patients at increased risk of metabolic and cardiovascular complications. Future \u201cad hoc\u201d randomized clinical trials should be designed to address the effects of weight reduction and /or different diet and/or nutritional supplementation on these parameters

Dietary fiber and gut microbiota in renal diets

Nutrition is crucial for the management of patients affected by chronic kidney disease (CKD) to slow down disease progression and to correct symptoms. The mainstay of the nutritional approach to renal patients is protein restriction coupled with adequate energy supply to prevent malnutrition. However, other aspects of renal diets, including fiber content, can be beneficial. This paper summarizes the latest literature on the role of different types of dietary fiber in CKD, with special attention to gut microbiota and the potential protective role of renal diets. Fibers have been identified based on aqueous solubility, but other features, such as viscosity, fermentability, and bulking effect in the colon should be considered. A proper amount of fiber should be recommended not only in the general population but also in CKD patients, to achieve an adequate composition and metabolism of gut microbiota and to reduce the risks connected with obesity, diabetes, and dyslipidemia

Anti-oxidant, anti-glycant, and inhibitory activity against \u3b1-amylase and \u3b1-glucosidase of selected spices and culinary herbs

Aqueous and methanol extracts of dry sage, rosemary, basil, parsley, chili, garlic and onion were analyzed to investigate their anti-oxidant and anti-glycant activities and in vitro inhibitory potential against enzymes involved in glycemic regulation. The aqueous extracts of rosemary and sage were the richest in phenolic compounds and showed the highest ability in binding iron and inhibiting DPPH, superoxide radicals and advanced glycation end-product production, lipid peroxidation, and the activity of a-glucosidase and a-amylase. On the other hand, the methanol extracts of both these Labiatae were less efficient than those of garlic, onion, parsley and chili in scavenging hydroxyl radicals. As far as protein glycation is concerned, methanol extracts were more effective in inhibiting the production of Amadori compounds and the aqueous ones in preventing advanced glycation endproduct formation. Therefore these spices may be preventive not only against cardiovascular diseases but also type 2 diabetes

Plant-based kidney diets prescribed in nutrition clinics: clinical advantages with low risks of hyperkalemia

A diet rich in plant-based foods, such as vegetables and grains, may help to prevent and slow the progression of chronic kidney disease (CKD), compared to animal-based foods. Patients affected by CKD are often affected by several comorbidities, such as type 2 diabetes, hypertension, and heart disease, determining the challenging task of preparing a diet that should take into account contrasting limitations regarding caloric, protein, and electrolytes intake. Thus, professional nutritional intervention is an essential strategy to manage signs and symptoms in CKD, including hyperkalemia (HK), a frequent complication of CKD

Oxidative state and lipid composition of plasma from overweight and moderately obese women

Objective: To determine the oxidative balance and plasma fatty acid composition of overweight and obese women. Design: Comparative, descriptive study on 60 overweight or obese (> 25 BMI> 33), normotensive, non-diabetic women and 60 age-matched lean healthy women (BMI< 25). Measurements: Plasma lipid, hydroperoxide, and antioxidants levels, fatty acid composition and lipoproteins susceptibility to peroxidation. Results: Compared to the lean control group, the patient group had higher lipoprotein susceptibility to peroxidation and higher peroxide levels. On the contrary, the polyunsaturated fatty acids, in particular the omega-3 species, and the antioxidants were lower in the patient group. Conclusions: The present study shows that overweight and obese people have oxidative balance impairment. The higher susceptibility to peroxidation of lipoproteins is the probable molecular mechanism that promotes a reduction in high unsaturated (and in particular omega-3) fatty acids, as well as antioxidants in the plasma of the overweight and obese subjects

Oxidizability of core and surface of lipoproteins as early marker of metabolic syndrome

INTRODUCTION Central obesity is a principal causative factor in the development of metabolic syndrome (MS), a common and complex disorder combining hypertension, insulin resistance, and alterations in the composition and function of lipoproteins. Oxidative stress is an important pathogenic mechanism of obesity-associated MS. Peroxidation of lipoproteins not only makes LDLs atherogenic but can also reduce the anti-atherogenic properties of HDL. OBJECTIVE The aim of this study was to investigate the oxidizability of the hydrophobic core and the surrounding envelope of LDL and HDL in obese males. METHODS Fifty normal-weight (CT) and 60 obese (25&lt; BMI&lt;35 Kg/m2 OB; 40 without MS, wMS; 20 with MS according to ATP III criteria, MS) adult males were studied. Core and surface of LDL and HDL were labeled by incubating plasma with selective pyrenic probes before isolation of lipoproteins by ultracentrifugation. Susceptibility to 2,2'-azobis-2-methyl-propanimidamide-dihydrochloride-induced peroxidation was measured following kinetically the decrease of fluorescence of the probes. The length of the lag phase and maximum velocity of the reaction were used as indices of lipoprotein oxidizability. Lipoprotein contents of proteins, cholesterol, phospholipids and triglycerides were determined by colorimetric assays. RESULTS The oxidizability of both core and surface were higher in both LDL and HDL of OB than in CT. The oxidizability of the two lipoprotein regions was higher in MS than in wMS, especially that of HDL core. This last parameter was inversely correlated with visceral adiposity (measured as waist to hip ratio). Moreover, triglycerides levels of LDL and HDL were higher in MS than in wMS. CONCLUSIONS The elevated oxidizability of lipoproteins found in MS could be due to increased oxidative stress and alterations of the composition. These preliminary results could be the rationale of future clinical trials addressed to investigate the effects of different hypocaloric diets and/or nutritional supplementations on these parameters