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Background: The relationship between hyperhomocysteinemia and cardiovascular disease has not been totally elucidated. Hypothesis: The study aimed to verify the association between hyperhomocysteinemia and endothelial dysfunction before and after modification of total homocysteine (tHcy) serum levels with vitamin supplementation in young male subjects devoid of any other cardiovascular risk factor. Methods: Twenty hyperhomocysteinemic (tHcy gt; 15 μmol/1) male volunteers (≤ 40 years) and 20 age-matched subjects with normal tHcy levels (tHcy < 13 μmol/1) were included. Exclusion criteria were smoking, hypertension, diabetes, vitamin ingestion, obesity, hypercholesterolemia, renal failure, and positive antiphospholipid antibodies. Serum tHcy, folate, vitamin B12 levels, activated protein C and S, protein C resistance, fibrinogen, prothrombin, thrombin, antithrombin III, and in vitro oxidation of low-density lipoprotein (LDL) particles were measured. Noninvasive ultrasound measurements of endothelium-dependent (EDD) and -independent dilatation (EID) of the brachial artery were performed. Each pair was then randomly assigned to receive a vitamin capsule (0.6 mg folic acid, 0.8 mg B12, and 2.0 mg B6) or an identical placebo during 8 weeks, in a double-blind study design. After the treatment phase, blood samples and vascular reactivity were repeated. Results: Nine pairs of volunteers received vitamins and 11 received placebo. Hyperhomocysteinemic subjects had lower baseline serum levels of vitamin B12. Serum folate levels, antithrombotic function, in vitro LDL oxidation, and EDD were similar in all groups. After the vitamin supplementation, serum folic acid levels increased significantly both in normo-and hyperhomocysteinemic subjects, unlike vitamin B12, which increased only in the hyperhomocysteinemic individuals. Plasma tHcy decreased significantly in the supplemented groups. Treatment with vitamins was not associated with improvement in EDD or antithrombotic function. Conclusions: Mild hyperhomocysteinemia is not associated with endothelial dysfunction in young male subjects with no additional cardiovascular risk factors, and reduction of tHcy by vitamin supplementation does not modify EDD in this age group. In this sample, tHcy was more related to vitamin B12 than to folic acid status.

Alcohol ingestion decreases plasma free fatty acids (FFAs) and lipid oxidation. This study was conducted to determine palmitate turnover in alcoholics during a short abstinence period and after an ethanol load and in a group of nonalcoholic control subjects, looking for correlations between palmitate turnover, FFA, acetate, and acetoacetate/β hydroxybutyrate ratio (AKBR). Palmitate C14 turnover was studied in five alcoholics during early abstinence and after a 0.8 g/kg ethanol load, and in five nonalcoholic normal controls. Plasma levels of FFA, acetate, acetoacetate, and β hydroxybutyrate were measured before and during the ethanol load. A needle hepatic biopsy was performed in alcoholics. FFA levels, palmitate flux, oxidation, and nonoxidative disposal were similar in alcoholics compared with control subjects, decreasing significantly after the ethanol load in both groups. AKBR and ketone bodies were similar in both groups in the basal period. After the alcohol infusion, AKBR decreased significantly. Acetoacetate levels did not change, and β hydroxybutyrate and total ketone bodies increased significantly in alcoholics and control subjects. A positive correlation was found between FFA levels and palmitate flux. Liver biopsies showed mild changes in the patients studied. The similar inhibition of lipid turnover, FFA release, and the drop in AKBR observed after an alcohol load in alcoholics and control subjects suggest that this effect is mediated by alcohol metabolism and not by metabolic alterations present in alcoholics.

Introducción: Las pastas secas (industrializadas) se caracterizan por ser manufacturadas a base de harina dura de trigo y otros cereales, llamado semolina, a diferencia del pan que se prepara con harina fina, lo que supone que la respuesta insulinémica y glicémica debiera ser menor que la del pan. Objetivo: Medir la respuesta glicémica e insulinsulinémica de una pasta seca estándar y una pasta seca enriquecida con huevo, de presentación larga (espagueti) y corta (corbata). Material y Métodos: El índice glicémico (IG) e índice insulinémico (II) se determinaron en 10 sujetos sanos entre 26 y 58 años de edad. En forma aleatoria a cada sujeto se le midió la glicemia e insulina en ayuno y después de ingerir en forma isoglucídica alimento estándar (pan marraqueta) o los 2 tipos de pasta en presentación larga o corta a los 15,45,60,90,120,150 y 180 minutos. Posteriormente se calculó el área bajo la curva (ABC) de glucosa e insulina en cada sujeto. Los IG e II fueron calculados como la razón entre el ABC para un alimento de prueba dado y el ABC del alimento estándar (considerado el 100%). RESULTADOS : Ambos tipos de pasta en presentación larga y corta presentaron menor IG que el alimento estándar (marraqueta) ( pasta larga A: 47,8±54,4, pasta larga B: 58,6±95,4%; pasta corta A:71,4±32,8%, pasta corta B: 79,9±4,.6% p

The study of the effects of bariatric surgery on quality of life in patients of different socioeconomic levels (SEL) is worthwhile.To study quality of life (QoL), eating behavior, depressive symptoms and sexuality in patients subjected to a gastric bypass (GBP) more than 1 year before.The sample was composed of 33 GPB patients (19 high SEL and 14 low SEL), and 27 non-operated women (18 high SEL and 9 low SEL) of similar weight and age, as controls. Assessment included medical history anthropometry radiological densitometry. Eating behavior was assessed using the three factor eating questionnaire, quality of life using SF-36 and the Bariatric Analysis of Reporting Outcome System (BAROS) depressive symptoms were assessed using the Beck scale version II and sexual behavior using the female sexual function index (FSFI).QoL was lower in operated patients from low SEL, especially when compared to high SEL control women. Operated patients had a predominantly restrictive pattern of eating behavior Eating behavior disorders were detected in 5 of 33 operated patients versus 4 of 27 controls (p =ns). Sexual function was absent or dysfunctional in 22 operated versus 8 controls (p =0,02). No significant differences were observed for depressive symptoms, between operated patients and controls.In the long term, QoL of bariatric patients, especially those from low SEL, is inferior to control women and Chilean general population. Operated patients have restrictive eating patterns and lower sexual satisfaction indexes. Frequency of depressive symptoms was high both in bariatric and control women.

Background: The study of the effects of bariatic surgery on quality of life in patients of different socioeconomic levels (SEL) is worthwhile. Aim: To study quality of life (QoL), eating behaviour, depressive symptoms and sexuality in patients subjected to a gastric bypass (GBP) more than 1 year before. Material and methods: The sample was composed of 33 GPB patients (19 high SEL and 14 low SEL), and 27 non-operated women (18 high SEL and 9 low SEL) of similar weight and age, as controls. Assessment included medical history, anthropometry, radiological densitometry. Eating behaviour was assessed using the three factor eating questionnaire, quality of life using SF-36 and the Bariatric Analysis of Reporting Outcome System (BAROS) depressive symptoms were assessed using the Beck scale version II and sexual behaviour using the female sexual function index (FSFI). Results: QoL was lower in operated patients from low SEL, especially when compared to high SEL control women. Operated patients had a predominantly restrictive pattern of eating behavior. Eating behavior disorders were detected in 5 of 33 operated patients versus 4 of 27 controls (p =ns). Sexual function was absent or dysfunctional in 22 operated versus 8 controls (p =0,02). No significant differences were observed for depressive symptoms, between operated patients and controls. Conclusions: In the long term, QoL of bariatric patients, especially those from low SEL, is inferior to control women and Chilean general population. Operated patients have restrictive eating patterns and lower sexual satisfaction indexes. Frequency of depressive symptoms was high both in bariatric and control women (Rev Med Chile 2009; 137: 625-33). (Key words: Bariatric surgery; Quality of life; Socioeconomic factors)

In acute illnesses, plasma glucose levels are often increased and generally parallel the severity of stress. Hyperglycemia caused by reduced insulin sensitivity and reduced insulin secretion is associated with increased susceptibility to infections. Maintaining blood glucose levels at or below 110 mg/dl reduces morbidity and mortality in critically ill patients.To measure the glucose and insulin responses of four commercially available enteral formulas compared with a standard meal reference product.The glycemic index (GI) and the insulin index (II) were determined in a randomized, cross over protocol in 38 healthy volunteers between 18 and 46 years of age. Each subject underwent five tests: three with the standard meal (bread) and two with the study products. The enteral formulas were Clinutren HPR (whole protein of high protein value), Crucial (casein peptide based formula), Peptamen, (whey peptide based formula), Glytrol (formula for diabetics with whole protein with fiber). Each study product was evaluated 10 times.The diabetic formula and the high protein energy dense formulas induced a significantly lower GI (p0.02) compared with the standard meal. The GI response did not appear to be due to enhanced insulin secretion. The other tested formulas had lower GI than the standard meal, but in addition they exhibited increased II The whey based peptide formulation produced the highest insulin response (p0.03).Both GI and II are related to the concentration, form and type of protein contained in the enteral formula. The whey peptide formulation produced a low GI with the highest insulin index. Based on the low GI of these enteral products, all can be useful to provide nutritional support during metabolic stress, without adding an additional challenge to blood glucose management.

Background: In acute illnesses, plasma glucose levels are often increased and generally parallel the severity of stress. Hyperglycemia caused by reduced insulin sensitivity and reduced insulin secretion is associated with increased susceptibility to infections. Maintaining blood glucose levels at or below 110 mg/dl reduces morbidity and mortality in critically ill patients. Aim: To measure the glucose and insulin responses of four commercially available enteral formulas compared with a standard meal reference product. Material and Methods: The glycemic index (GI) and the insulin index (II) were determined in a randomized, cross over protocol in 38 healthy volunteers between 18 and 46 years of age. Each subject underwent five tests: three with the standard meal (bread) and two with the study products. The enteral formulas were Clinutren HPR (whole protein of high protein value), Crucial® (casein peptide based formula), Peptamen®, (whey peptide based formula), Glytrol® (formula for diabetics with whole protein with fiber). Each study product was evaluated 10 times. Results: The diabetic formula and the high protein energy dense formulas induced a significantly lower GI (p

Background: Energy restriction (ER) extends life span in animals, by decreasing oxidative stress. Aim: To compare adiposity, metabolic variables and DNA oxidative damage, among adults, reporting a constant body weight (weight maintainers), versus those reporting a progressive increase (weight gainers). Subjects and Methods: Clinical history, dietary recall, anthropometric measures, abdominal CT scan and fasting blood samples (to measure lipoproteins, glucose and insulin), were obtained in 44 males. These subjects were classified as weight maintainers if they had a change in weight of 3 kg or less in the last 10 years, or weight gainers, if they had a weight increment of more than 6 kg in the same lapse. Oxidative damage was assessed by 8-hydroxydeoxyguanosine (8-OHdG), in DNA extracted from circulating lymphocytes, in 5 weight maintainers, 8 weight gainers and 5 healthy elders. Results: Energy intake was 18% higher in weight gainers (p

Pelvic radiotherapy induces acute small bowel injury but its effects on nutritional status are unknown. The objective of this study was to prospectively evaluate nutritional, functional and morphologic intestinal changes, after radiotherapy.Fifteen patients were studied before and after pelvic irradiation. A clinical, nutritional and routine clinical laboratory assessment was performed. Nutritional parameters included dietary recall, subjective global assessment, anthropometric measurements (body mass index, skinfold thickness at four sites and circumferences of arm, waist and hip), hand grip strength, indirect calorimetry and Dual Energy X-ray absortiometry (DEXA). Intestinal parameters included permeabilty to sugars (assessed by lactulose and mannitol urinary excretion), intestinal transit time (measured by hydrogen breath test after ingestion of lactulose) and jejunal biopsies.Thirteen patients presented diarrhea during radiation therapy. After five weeks, intestinal permeability increased, while intestinal transit time decreased. The second biopsy showed hypertrophy of villae and crypts. Simultaneously, patients lost weight at the expense of fat free mass. Resting energy expenditure was elevated prior to treatment and declined after five weeks. Changes in caloric ingestion were not significant.Our results indicate that pelvic radiation induces a loss of fat free mass along with intestinal morphologic and functional changes.

The contribution of high serum levels of cholesterol to atherogenesis has been widely recognized, but the mechanisms are not completely clear. Numerous publications have emphasized that oxidized, but not native low-density lipoproteins, are the particles incorporated into the arterial wall. A group of receptors generically called "scavenger" (SR), actively bind these modified lipoproteins and incorporate them into monocytes-macrophages, in the arterial intima. SR are not down regulated by intracellular concentrations of cholesterol, thus accumulating huge amounts of lipids, transforming monocyte-macrophages into foam cells, predominant cell type of the fatty streak. The simultaneous cytokine production and migration of other cellular types progressively transform this initial lesion into the organized atherosclerotic plaque. In this setting SR, which are up-regulated by oxidized LDL, play a central promoting role. Its presence has been demonstrated in arterial plaques both in human and animal models, and its blockade protects animals from development or progression of atherosclerosis. In humans, elevated antibody titers to oxidized LDL in patients with coronary stenosis, and increased SR activity, in pro-atherogenic conditions such as haemodialysis, indicate that this model may operate as well, but the evidences are still not solid enough to definitively conclude that the oxidized-LDL-SR hypothesis is a finished puzzle.

The objective of this study was to compare the values obtained for total body fat obtained with deuterium dilution, anthropometry and bioimpedance in 41 institutionalized elderly individuals (65-90 years old). The values obtained with each technique were compared using the graphic analysis proposed by Bland and Altman, that plots the difference between measurements with both methods against their average. In men (n = 20) and women (n = 21), the best degree of agreement was obtained between the values measured by deuterium dilution and those calculated from skinfolds (mean difference = 1.4% and 6.9%, respectively). The limits of agreement (+/-2SD), for skinfolds reached a maximum of 14.8% in men, and 16.8% in women. These values tend to underestimate fat in the obese and overestimate it in thinner subjects. For bioimpedance and deuterium dilution, the inter-method difference is significantly greater: 9.3% in men and 14.7% in women. This lack of agreement is attributed to the fact that the bioimpedance equipment utilizes equations validated for younger adults. In conclusion, estimation of body composition using skinfoids has the smallest difference compared to deuterium dilution, even though individual measurements are not clinically acceptable. Caution is recommended when using measurements of body composition in the elderly, due to large errors in the determinations.