Nutrition

Perioperative metabolic changes in patients undergoing cardiac surgery

Stephan M. Jakob, Zeno Stanga — 2010-01-06

Abstract: Perioperative metabolic changes in cardiac surgical patients are not only induced by tissue injury and extracorporeal circulation per se: the systemic inflammatory response to surgical trauma and extracorporeal circulation, perioperative hypothermia, cardiovascular and neuroendocrine responses, and drugs and blood products used to maintain cardiovascular function and anesthesia contribute to varying degrees. The pathophysiologic changes include increased oxygen consumption and energy expenditure; increased secretion of adrenocorticotrophic hormone, cortisol, epinephrine, norepinephrine, insulin, and growth hormone; and decreased total tri-iodothyronine levels. Easily measurable metabolic consequences of these changes include hyperglycemia, hyperlactatemia, increased aspartate, glutamate and free fatty acid concentrations, hypokalemia, increased production of inflammatory cytokines, and increased consumption of complement and adhesion molecules. Nutritional risk before elective cardiac surgery—defined as preoperative unintended pathologic weight loss/low amount of food intake in the preceding week or low body mass index—is related to adverse postoperative outcome. Improvements in surgical techniques, anesthesia, and perioperative management have been designed to minimize the stressful stimulus to catabolism, thereby slowing the wasting process to the point where much less nutrition is required to meet metabolic requirements. Early nutrition in cardiac surgery is safe and well tolerated.

Role of enteral nutrition and pharmaconutrients in conditions of splanchnic hypoperfusion

2009-12-09

Abstract: In critically ill patients there is consistent evidence that significant benefits are achieved if nutrients are delivered within the gut compared with the parenteral route. However, in conditions related to gut hypoflux, enteral nutrition may play a double role in counterbalancing the installed low-flow state. On the one hand, enteral-induced postprandial hyperemia may preserve the mucosal barrier and ameliorate immune competence; on the other hand, feeding by the gut may pose a theoretical risk of intestinal ischemia. Despite limited investigation, a strategic temporary minimal enteral nutrition with hypocaloric content has been recommended recently aiming to avoid the overfeeding syndrome and the menace of gut hypoperfusion. Under these conditions, the early luminal delivery of key nutrients such as arginine, glutamine dipeptides, antioxidants, and butyrate are an attractive option for this subset of patients. Arginine may prevent intestinal injury due to hypoperfusion but may harm the gut if ischemia is established. In contrast, glutamine may promote benefits in both conditions. Further investigations by randomized trials in this field are necessary.

Pomegranate juice polyphenols increase recombinant paraoxonase-1 binding to high-density lipoprotein: Studies in vitro and in diabetic patients

Bianca Fuhrman, Nina Volkova, Michael Aviram — 2009-09-18

Abstract: Objective: The high-density lipoprotein (HDL)-associated paraoxonase-1 (PON1)/free PON1 ratio is lower in diabetic patients in comparison with healthy controls. Because diabetes is associated with increased oxidative stress, we hypothesized that a labeled recombinant PON1 (rePON1) would detect differences in HDL capacity to bind PON1 under specific experimental conditions, such as oxidation, addition of polyphenols, or in vivo dosing of diabetic patients with polyphenols.Methods: In the present study we determined labeled rePON1 binding to HDL under various oxidative conditions by using polyacrylamide gel electrophoresis for the separation of free labeled rePON1 from HDL-bound labeled rePON1.Results: The HDL-rePON1/free rePON1 ratio gradually decreased as the extent of HDL oxidation increased, and the antioxidants vitamin E or pomegranate juice (PJ) inhibited the redistribution of rePON1. PJ or its purified polyphenols, punicalagin, gallic acid, or ellagic acid, increased rePON1 binding also to non-oxidized HDL. Further, rePON1 associated more efficiently with HDLs isolated from diabetic patients after PJ consumption versus HDLs isolated before PJ consumption.Conclusions: We conclude that 1) oxidative stress impairs binding of fluorescein isothiocyanate–labeled rePON1 to HDL and 2) PJ polyphenols directly increase the HDL-rePON1 association beyond their antioxidative effect.

Improvement of constipation and liver function by plant-derived lactic acid bacteria: A double-blind, randomized trial

2009-07-23

Abstract: Objective: Lactic acid bacteria (LAB) contribute to human health; however, the probiotic properties vary among strains classified into the same species. The primary objective of this study was to evaluate the effects of yogurts made by different types of LAB on the gastrointestinal system. The yogurts were also evaluated by measuring serum lipid contents and liver functional indicators as a secondary objective.Methods: Healthy human adults (n = 68) with some complaints with regard to intestinal health, including constipation and diarrhea, were randomly assigned to receive one of three types of yogurt in a double-blind manner: type A, a yogurt made by plant-derived LAB (mainly Lactobacillus [Lb.] plantarum SN35N); type B, a yogurt made by plant-derived LAB (mainly Lb. plantarum SN13T); and type C, a yogurt made by animal-derived LAB (mainly Lactococcus lactis A6 and Streptococcus thermophilus 510) as a control. The subjects consumed 100 g of yogurt daily for 6 wk. Data were collected from clinical visits at 2-wk intervals and by diaries used to record defecation and health conditions.Results: Drastic and constant increments of defecation frequency in subjects with constipation were observed with type A and B yogurts but not with type C yogurt. Type B and C yogurts resulted in decreases in total and low-density lipoprotein cholesterol. The serum concentrations of liver functional parameters were improved by the type B yogurt (12–25% reduction).Conclusion: The present study suggests that Lb. plantarum SN13T exhibits a superior probiotic effect on constipation in addition to improving the serum lipid contents and liver function.

The safety of oral use of l-glutamine in middle-aged and elderly individuals

2009-09-18

Abstract: Objective: To evaluate the safety of nutraceutical oral administration of l-glutamine (l-Gln) in middle-aged and elderly individuals.Methods: In this randomized, crossover, double-blind clinical study, 30 residents of a long-term–care institution, selected according to a modified SENIEUR protocol (Working Party of the EURAGE Concerted Action Programme on Ageing of the European Community), were studied. Fourteen subjects received orally 0.5g · kg−1 · d−1 of l-Gln and 16 received calcium caseinate for 14 d, followed by a 5-d washout. Supplements were switched for the second 14-d trial. Laboratory tests for hepatic and renal functions and ammonemia were performed and the estimated glomerular filtration rate (eGFR) was calculated.Results: Of the 30 subjects, 16 were men, mean age was 69±8.8 y, average weight was 61.8±14.2kg, and mean serum albumin was 4.0±0.3g/dL. Neither adverse clinical effects nor clinically significant laboratory changes were noted during l-Gln supplementation. There was no difference in ammonemia between the groups. There were statistically but not clinically significant increases in plasma urea nitrogen and creatinine concentrations. There was no significant decrease in eGFR during calcium caseinate supplementation (−2.9%). The eGFR decreased significantly after l-Gln supplementation (−13.3%) but well below the 25% limit for biologic significance.Conclusion: Increases in serum urea nitrogen and creatinine and decrease in eGFR are probably due to difficulties by older kidneys in metabolizing the supplemented protein sources. Although not clinically significant, those alterations impose a rigorous control on the evaluation parameters of renal function during oral l-Gln supplementation, with doses of 0.5g · kg−1 · d−1 in middle-aged and elderly individuals.

Visceral adipose tissue and body fat mass: Predictive values for and role of gender in cardiometabolic risk among Turks

Altan Onat, Murat Uğur, Günay Can, Hüsniye Yüksel, Gülay Hergenç — 2009-07-27

Abstract: Objective: We investigated the predictive values of visceral adipose tissue area (VAT) and body fat mass for a composite endpoint consisting of type 2 diabetes and coronary heart disease and for incident metabolic syndrome.Methods: We analyzed at 4-y follow-up 157 middle-aged men and women in whom body composition analyzer and single-scan computerized tomography had been used.Results: Sex- and age-adjusted mean areas of visceral fat were 1.5-fold greater in individuals with than without the composite endpoint (P<0.001), whereas abdominal subcutaneous fat was similar. Analysis of receiver operating characteristics for the optimal criterion regarding the composite endpoint (in 37 participants) indicated a VAT of 130cm2 and accuracies of 60% in men and 85% in women. Whereas age-adjusted VAT alone significantly predicted the composite endpoint in men, body fat mass or VAT predicted it in women (with 2.2- to 2.6-fold relative risks for 1-SD increment). Age-adjusted incident metabolic syndrome was significantly predicted by each parameter in men but only by fat mass in women.Conclusion: Visceral adiposity in men and body fat mass in women seem to be of greater relevance in cardiometabolic risk for the prediction of which 130cm2 of VAT in both sexes and/or 27kg of fat mass in women are useful cutoffs. Sex differences may reflect the predominating role of visceral adiposity in men and of insulin resistance in women in this risk.

Diet patterns of lactovegetarian adolescent girls: Need for devising recipes with high zinc bioavailability

Rama Tupe, Shashi A. Chiplonkar — 2009-07-23

Abstract: Objective: Populations subsisting on plant foods are believed to be at a high risk of mineral deficiencies. The aim of the present study was to examine the diet patterns of vegetarian adolescent girls for zinc adequacy and devise recipes to improve bioavailable zinc intakes.Methods: A cross-sectional survey was carried out in 630 schoolgirls (10–16 y old) from Pune, India, from 2006 to 2007. Diet was assessed by a 24-h recall method on 3 random days. Diet patterns were identified by principal component analysis. Nutrient intakes were estimated using the cooked-foods database of our laboratory. Twenty recipes representing the diet patterns were formulated using foods that have a high zinc content and using methods such as sprouting/fermentation. In vitro zinc dialyzability of the recipes was determined by simulating gastrointestinal conditions and atomic absorption spectrometry.Results: Five diet patterns were identified reflecting intakes of different cereals. Girls in the five diet patterns had inadequate intakes of energy, protein, and micronutrients including zinc compared with the recommended dietary intakes of India. In the new cereal-based recipes, the average contents of energy, protein, iron, calcium, zinc, β-carotene, and vitamin C per 100g of cooked weight were 205kcal, 6.2g, 2.5mg, 105mg, 1.5mg, 716μg, and 4.4mg, respectively. Therefore, a supplement of 200g of the recipe would fulfil 75% of the daily zinc requirement of adolescents and increase other micronutrient intake manifolds.Conclusion: Diets of Indian schoolgirls were deficient in zinc. Zinc-rich recipes with high bioavailability have the potential to alleviate zinc deficiency in adolescents.

Effect of pistachio diet on lipid parameters, endothelial function, inflammation, and oxidative status: A prospective study

2009-08-03

Abstract: Objective: Recent studies have suggested that nuts have favorable effects beyond lipid lowering. We aimed to investigate effect of the Antep pistachio (Pistacia vera L.) on blood glucose, lipid parameters, endothelial function, inflammation, and oxidation in healthy young men living in a controlled environment.Methods: A Mediterranean diet was administered to normolipidemic 32 healthy young men (mean age 22 y, range 21–24) for 4 wk. After 4 wk, participants continued to receive the Mediterranean diet but pistachio was added for 4 wk by replacing the monounsaturated fat content constituting ≈20% of daily caloric intake. Fasting blood samples and brachial endothelial function measurements were performed at baseline and after each diet.Results: Compared with the Mediterranean diet, the pistachio diet decreased glucose (P<0.001, −8.8±8.5%), low-density lipoprotein (P<0.001, −23.2±11.9%), total cholesterol (P<0.001, −21.2±9.9%), and triacylglycerol (P=0.008, −13.8±33.8%) significantly and high-density lipoprotein (P=0.069, −3.1±11.7%) non-significantly. Total cholesterol/high-density lipoprotein and low-density lipoprotein/high-density lipoprotein ratios decreased significantly (P<0.001 for both). The pistachio diet significantly improved endothelium-dependent vasodilation (P=0.002, 30% relative increase), decreased serum interleukin-6, total oxidant status, lipid hydroperoxide, and malondialdehyde and increased superoxide dismutase (P<0.001 for all), whereas there was no significant change in C-reactive protein and tumor necrosis factor-α levels.Conclusion: In this trial, we demonstrated that a pistachio diet improved blood glucose level, endothelial function, and some indices of inflammation and oxidative status in healthy young men. These findings are in accordance with the idea that nuts, in particular pistachio nuts, have favorable effects beyond lipid lowering that deserve to be evaluated with prospective follow-up studies.

Bile duct obstruction is associated with early postoperative upregulation of liver uncoupling protein-2 and reduced circulating glucose concentration in the rat

2009-07-27

Abstract: Objective: To evaluate whether upregulation of liver and muscle uncoupling protein 2 (UCP-2) is an acute phenomenon in obstructive jaundice and associated with secondary metabolic effects.Methods: Male Sprague-Dawley rats were divided into four groups: bile duct ligated (BDL) and sham-operated pair-fed (PF), ad libitum fed (AL), and controls. BDL, PF, and AL rats were further divided into subgroups according to the interval postoperatively when they were reanesthetized and sampled for tissue and blood: 2, 4, and 8 d, respectively. Bilirubin, liver enzymes, glucose, free fatty acids, and insulin in blood plasma were analyzed. Liver and muscle tissue were sampled for UCP-2 and adenosine triphosphate analysis.Results: The BDL rats showed an increase of the liver UCP-2 expression compared with PF and AL rats (P<0.05) 4 d postoperatively. Liver adenosine triphosphate in BDL rats showed a decrease compared with sham-operated controls at all intervals (P<0.05). Plasma glucose concentration in BDL rats was decreased compared with the other groups. Free fatty acids showed an initial increase 2 d postoperatively compared with sham-operated controls and PF and AL rats (P<0.05) at the corresponding time point.Conclusion: Obstructive jaundice is associated with an early upregulation of liver UCP-2, reduced liver adenosine triphosphate content, and decreased plasma glucose concentration, supporting the hypothesis that obstructive jaundice results in impaired energy homeostasis in the liver, which might cause decreased glucose output and hypoglycemia as a consequence.

Effect of high-fat feeding on expression of genes controlling availability of dopamine in mouse hypothalamus

2009-10-07

Abstract: Objective: Hypothalamic centers integrate external signals of nutrient availability and energy status and initiate responses to maintain homeostasis. Quantifying changes in hypothalamic gene expression in the presence of nutrient excess may identify novel responsive elements.Methods: Affymetrix Mouse Genome 430 2.0 oligonucleotide microarrays containing 45 102 probe sets were used to interrogate differential expression of genes in dietary-induced obesity model C57BL6 inbred mice fed a high-fat (35% fat; n=8) or standard (4% fat; n=6) diet from 3 to 15 wk of age. Ontologies of regulated genes were examined and expression of selected genes was validated by quantitative real-time polymerase chain reaction.Results: One thousand two hundred twelve unique gene transcripts showed altered expression on the microarrays. Gene ontology analysis revealed changes in neuropeptide genes responding to leptin, Pomc, Cart, Npy, and Agrp, compatible with a homeostatic response to high-fat intake, although mean weight increased 2.3-fold compared with standard fed mice (P<0.001). Neurotransmitter system ontologies revealed upregulation of five genes controlling availability of dopamine. Changes in Th tyrosine hydroxylase (2.1-fold) and Slc18a2 solute carrier family 18 (vesicular monoamine), member 2 (4.4-fold) controlling synthesis and release, and Slc6a3 solute carrier family 6 (neurotransmitter transporter, dopamine), member 3 (4.8-fold), Snca α-synuclein (1.3-fold), and Maoa monoamine oxidase (1.9-fold) limiting availability were confirmed by quantitative real-time polymerase chain reaction.Conclusion: Expression of five genes involved in availability of dopamine was increased after a high-fat diet. Failure to reduce dopamine availability sufficiently, to counter the feeding reward effect, could contribute to diet-induced obesity in these mice.

Developmental and neurobehavioral effects of perinatal exposure to diets with different ω-6:ω-3 ratios in mice

2009-11-20

Abstract: Objective: To investigate in mice the effect of diets enriched with soy or sunflower oil with different ω-6:ω-3 ratios on gestation, reproductive success, physical maturation, and the neurobiological development of the pups.Methods: Dams were assigned, throughout gestation and lactation, to different groups: a commercial diet (CD), a soy oil–enriched diet (SOD), or a sunflower oil–enriched diet (SFOD). Measurements during gestation were dams' body weights and daily food intakes. Measurements in the offspring were physical parameters (body weight, body length, body mass index, fur appearance, pinna detachment, incisor eruption, eye opening, and puberty onset) and behavioral preweaning tests (surface righting reflex, negative geotaxis, and cliff avoidance).Results: The SOD and SFOD dams became significantly heavier than the CD dams from gestational days 14 and 19, respectively, to parturition. There were no significant differences in gestational length or food consumption during pregnancy or lactation or in maternal weight during lactation. Diets did not modify litter size, sex ratio, survival index at weaning, or body weight. The SFOD and SOD offspring were significantly shorter than the CD offspring at weaning. The mean offspring physical scores of SOD and SFOD offspring were higher than CD offspring and simple reflexes were earlier in the SOD and SFOD groups. In SFOD offspring, puberty onset was significantly delayed, at postnatal days 26 and 27 in male and female offspring, respectively.Conclusion: This study suggests that the maintenance of an adequate ω-6:ω-3 ratio is necessary for the optimal growth and development of murine offspring. In populations that do not have sufficient provision of polyunsaturated fatty acids in the diet, their consumption would be advisable during gestation and lactation because these improve most neurodevelopmental outcomes included in this study.

Defining malnutrition: Mission or mission impossible?

2009-12-03

Abstract: Objective: Although screening for malnutrition in health care has expanded enormously, a gold standard for the optimal definition and operationalism of malnutrition is still lacking. This report reflects expert opinions on the elements of the definition and operationalism of malnutrition and is meant to trigger further debate within the nutritional societies.Methods: A Delphi study was performed consisting of three phases. After a literature review (phase 1), questions for a semistructured interviews (phase 2) were formulated. Subsequently, the results of these semistructured interviews were used to develop the final list of elements (for defining and operationalism of malnutrition). In phase 3 (final phase), experts were asked to provide written feedback regarding the ranking of elements concerning the importance of these elements.Results: Twenty-two experts (response 73.3%) were included in the final phase of this Delphi study. No overall agreement could be reached. The elements deficiencies of energy or protein and decrease in fat-free mass were most often mentioned to be particularly important in defining malnutrition. Elements mentioned to be important in operationalism of malnutrition were involuntary weight loss, body mass index, and no nutritional intake. Opinions on cutoff points regarding these elements differed strongly among experts.Conclusion: This study shows that there is no full agreement among experts on the elements defining and operationalism of malnutrition. The results of this study may fuel the discussion within the nutritional societies, which will most ideally lead to an international consensus on a definition and operationalism of malnutrition.

Soybean diet alters the insulin-signaling pathway in the liver of rats recovering from early-life malnutrition

2009-11-02

Abstract: Objective: We investigated if alterations in the insulin-signaling pathway could contribute to reduced hepatic glycogen levels in adult rats subjected to a protein deficiency during intrauterine life and lactation and reared through to recovery on a soybean diet.Methods: Rats from mothers fed with 17% or 6% protein (casein) during pregnancy and lactation were maintained with a 17% casein diet (offspring born to and suckled by mothers fed a control diet and subsequently fed the same diet after weaning [CC group] and offspring born to and suckled by mothers fed a control diet and subsequently fed a soybean flour diet with 17% protein after weaning [CS group]), a soybean diet (offspring of mothers fed a low-protein diet and a control diet after weaning [LC group] and offspring of mothers fed a low-protein diet and fed a soybean flour diet containing 17% protein after weaning [LS group]), or a 6% casein diet (offspring of mothers fed a low-protein diet and subsequently fed the same diet after weaning [LL group]) from weaning until 90 d of life.Results: A soybean diet did not modify basal serum glucose and glucagon concentrations, but raised basal serum insulin and consequently increased the serum insulin/glucose ratio. Insulin receptor and insulin receptor substrate-1 levels were lower in rats fed a soybean diet compared with those maintained with a casein diet. In the LS group, the p85 levels were higher than in the LC group, whereas in CS rats its expression was lower than in CC rats. The expression of p110 was lower in the CS group compared with the CC group and similar in the LS and LC groups. Insulin receptor substrate-1 phosphorylation was similar in the LS, LC, and CS groups and lower compared with the CC group. The insulin receptor substrate-1–p85/phosphatidylinositol 3-kinase association was lower in LS than in LC rats and in CS than in CC rats. Akt phosphorylation was lower in the CS and LS groups than in the CC and LC groups.Conclusion: Adult rats maintained with a soybean diet exhibited insulin resistance due, at least in part, to alterations in the early steps of the insulin signal transduction pathway.

Erythritol is a sweet antioxidant

2009-07-27

Abstract: Objective: Hyperglycemia, oxidative stress, and the onset and progression of diabetic complications are strongly linked. Reduction of oxidative stress could be of utmost importance in the long-term treatment of diabetic patients. The chronic nature of the disease calls for a mode of antioxidant intake that can be sustained easily, e.g., by the diet. Erythritol, a simple polyol, could be such a compound. It is orally available, well tolerated, and its chemical structure resembles that of mannitol, a well-known hydroxyl radical (HO•) scavenger.Methods: We studied the antioxidant properties of erythritol in vitro and subsequently determined its antioxidant activity and its vasoprotective effect in the streptozotocin diabetic rat.Results: Erythritol was shown to be an excellent HO• radical scavenger and an inhibitor of 2,2′-azobis-2-amidinopropane dihydrochloride–induced hemolysis but inert toward superoxide radicals. High-performance liquid chromatographic and electron spin resonance spectroscopy studies showed that the reaction of erythritol with hydroxyl radicals resulted in the formation of erythrose and erythrulose by abstraction of a carbon-bound hydrogen atom. In the streptozotocin diabetic rat, erythritol displayed an endothelium-protective effect and, in accordance with the in vitro experiments, erythrose was found in the urine of erythritol-consuming rats.Conclusion: Erythritol acts as an antioxidant in vivo and may help protect against hyperglycemia-induced vascular damage.

2010-04-01

Nutrition

Perioperative metabolic changes in patients undergoing cardiac surgery

Role of enteral nutrition and pharmaconutrients in conditions of splanchnic hypoperfusion

Pomegranate juice polyphenols increase recombinant paraoxonase-1 binding to high-density lipoprotein: Studies in vitro and in diabetic patients

Improvement of constipation and liver function by plant-derived lactic acid bacteria: A double-blind, randomized trial

The safety of oral use of l-glutamine in middle-aged and elderly individuals

Visceral adipose tissue and body fat mass: Predictive values for and role of gender in cardiometabolic risk among Turks

Diet patterns of lactovegetarian adolescent girls: Need for devising recipes with high zinc bioavailability

Effect of pistachio diet on lipid parameters, endothelial function, inflammation, and oxidative status: A prospective study

Bile duct obstruction is associated with early postoperative upregulation of liver uncoupling protein-2 and reduced circulating glucose concentration in the rat

Effect of high-fat feeding on expression of genes controlling availability of dopamine in mouse hypothalamus

Developmental and neurobehavioral effects of perinatal exposure to diets with different ω-6:ω-3 ratios in mice

Defining malnutrition: Mission or mission impossible?

Soybean diet alters the insulin-signaling pathway in the liver of rats recovering from early-life malnutrition

Erythritol is a sweet antioxidant

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