Branched-Chain Amino Acids and Insulin Resistance, from Protein Supply to Diet-Induced Obesity.

For more than a decade, there has been a wide debate about the branched-chain amino acids (BCAA) leucine, valine, and isoleucine, with, on the one hand, the supporters of their anabolic effects and, on the other hand, those who suspect them of promoting insulin resistance. Indeed, the role of leucine in the postprandial activation of protein synthesis has been clearly established, even though supplementation studies aimed at taking advantage of this property are rather disappointing. Furthermore, there is ample evidence of an association between the elevation of their plasma concentrations and insulin resistance or the risk of developing type 2 diabetes, although there are many confounding factors, starting with the level of animal protein consumption.

Chemically Defined Formulas, Symbiotics and Cow's Milk Protein Allergy.

Cow's milk protein (CMP) allergy (CMPA) is the earliest and most common food allergy in children [...

Effect of age, stress and protein supply on plasma amino acids during continuous enteral nutrition; a pragmatic study in rats.

Background & Aims: As life expectancy increases, an increasing older population may require surgery with perioperative nutritional management. While little is known about the combined effect of age and stress on amino acid metabolism during enteral nutrition, we hypothesized that blood amino acid bioavailability may be influenced not only by the characteristics of the ingested protein but also by intestinal ageing and splanchnic sequestration of amino acids. Plasma amino acid kinetics were thus evaluated in aged and adult rats receiving continuous enteral nutrition before and after standardized surgical stress.

Combined effect of citrulline and lactoserum on amino acid availability in aged rats.

Objective: Age-associated sarcopenia is due to anabolic resistance to feeding. Muscle protein synthesis is improved by fast proteins (e.g.

Obesity, Nutrients and the Immune System in the Era of COVID-19.

The past year has shown that obesity is a risk factor for severe complications of SARS-CoV-2 infection. Excess fat mass during obesity is known to be a risk factor for chronic diseases but also for severe infections and infectious complications. We have focused here on the elements responsible for this particular susceptibility to infections and more specifically to COVID-19.

Lkb1 suppresses amino acid-driven gluconeogenesis in the liver.

Excessive glucose production by the liver is a key factor in the hyperglycemia observed in type 2 diabetes mellitus (T2DM). Here, we highlight a novel role of liver kinase B1 (Lkb1) in this regulation. We show that mice with a hepatocyte-specific deletion of Lkb1 have higher levels of hepatic amino acid catabolism, driving gluconeogenesis.

Creatinine-to-cystatin C ratio and bioelectrical impedance analysis for the assessement of low lean body mass in cancer patients: Comparison to L3-computed tomography scan.

Objectives: Lean body mass (LBM) is an important prognostic factor in patients with cancer. Although the L3-computed tomography (CT) scan is considered a reference method for assessment, a convenient and easily available method for longitudinal follow-up is required. Although bioelectrical impedance analysis (BIA) is widely used, its accuracy is questioned; plasma creatinine-to-cystatin C (CC) ratio could be an attractive alternative.

Assessment of transthyretin cut-off values for a better screening of malnutrition: Retrospective determination and prospective validation.

The use of transthyretin (TTR, prealbumin) as a marker of malnutrition and the definition of associated cut-offs are a matter of debate. In order to clarify this issue, we performed a retrospective study and then a prospective validation one. In the first study, data from 23,617 consecutive patients from our University hospital were analysed.

Effect of citrulline on muscle protein turnover in an in vitro model of muscle catabolism.

Objective: Muscle net catabolism, as seen after severe trauma or sepsis or in postoperative situations, is mediated by hormones (e.g., cortisol) and proinflammatory cytokines (e.

Effect of aging on the availability of amino acids from an immune-enhancing diet (IED) after a surgical stress in rats.

Background & Aims: Dietary amino acid (AA) requirements increase after a surgical stress while the systemic AA availability from the diet decreases with age, due to splanchnic sequestration. While immune-enhancing diets (IEDs) have been recommended for the nutritional management of surgical patients, the systemic bioavailability of their AA supply has not been evaluated in elderly surgical patients. This was determined in surgically-stressed IED-fed aged rats.

Citrulline prevents age-related LTP decline in old rats.

The prevalence of cognitive decline is increasing as the ageing population is considerably growing. Restricting this age-associated process has become a challenging public health issue. The age-related increase in oxidative stress plays a major role in cognitive decline, because of its harmful effect on functional plasticity of the brain, such as long-term potentiation (LTP).

Lean Body Mass and Endocrine Status But Not Age Are Determinants of Resting Energy Expenditure in Patients with Non-Small Cell Lung Cancer.

Background: Cancer and aging are both frequently associated with malnutrition, a factor of poor prognosis. In adult cancer patients, this may be related in part to impaired energy metabolism, with higher than predicted resting energy expenditure (REE) in about 50% of patients. We hypothesized that frequently impaired energy metabolism in elderly patients could potentiate cancer-associated hypermetabolism, further promoting risk of malnutrition.

Is -Carbamoyl Putrescine, the Decarboxylation Derivative of Citrulline, a Regulator of Muscle Protein Metabolism in Rats?

-carbamoyl putrescine (NCP), the decarboxylation derivative of citrulline, metabolically related to polyamines, may exert biological effects in mammals. The aim of this study was (i) to evaluate the nutritional properties of NCP in healthy rats and (ii) to determine the effect of NCP administration on muscle metabolism in malnourished old rats. The nutritional properties of NCP were first evaluated in 20 8-week-old male rats randomized to receive for two weeks a standard diet either alone (C group) or supplemented with NCP, 5 or 50 mg/kg/d.

Hypermetabolism is an independent prognostic factor of survival in metastatic non-small cell lung cancer patients.

Background & Aims: Metastatic non-small cell lung cancer (NSCLC) is the first cause of cancer death worldwide. Increased resting energy expenditure (REE) is frequent among cancer patients and may contribute to cancer cachexia. The aim of this study was to examine the prognostic value of increased REE in metastatic NSCLC patients.

Citrulline production and protein homeostasis.

Purpose Of Review: Protein homeostasis is crucial for maintaining cell functions. Citrulline, an endogenous amino acid, is considered as an efficient source of arginine at systemic and cellular level. Accumulating evidence, obtained from citrulline supplementation studies, suggest anabolic properties especially in malnourished rodents and human.

Citrulline and muscle protein homeostasis in three different models of hypercatabolism.

Supplementation of enteral nutrition (EN) by specific amino acids (AAs) has been proposed to prevent muscle protein loss in intensive care unit (ICU) patients. Citrulline (Cit), which has been shown to stimulate muscle protein synthesis in other situations, may be of interest in this setting. Our aim was to assess the effect of Cit in three catabolic models relevant to critical illness: endotoxemia (LPS), traumatic brain injury (TBI), and TBI with infectious complications (TBI-Ec), which are characterized by different alterations in protein homeostasis.

Transthyretin for the routine assessment of malnutrition: A clinical dilemma highlighted by an international survey of experts in the field.

The value of transthyretin (TTR) measurement for assessing malnutrition is under debate due to its sensitivity to inflammation and frequent confusion over its meaning (i.e. as a marker of diagnosis, prognosis, or efficacy of refeeding).

Muscle Loss in Chronic Liver Diseases: The Example of Nonalcoholic Liver Disease.

Recent publications highlight a frequent loss of muscle mass in chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD), and its association with a poorer prognosis. In NAFLD, given the role of muscle in energy metabolism, muscle loss promotes disease progression. However, liver damage may be directly responsible of this muscle loss.

Are heterozygous carriers for hereditary fructose intolerance predisposed to metabolic disturbances when exposed to fructose?

Background: High fructose intake causes hepatic insulin resistance and increases postprandial blood glucose, lactate, triglyceride, and uric acid concentrations. Uric acid may contribute to insulin resistance and dyslipidemia in the general population. In patients with hereditary fructose intolerance, fructose consumption is associated with acute hypoglycemia, renal tubular acidosis, and hyperuricemia.

Influence of an ω3-fatty acid-enriched enteral diet with and without added glutamine on the metabolic response to injury in a rat model of prolonged acute catabolism.

Objective: In critically ill patients, acute injury alters gut function, causing greater risk for sepsis and malnutrition. Peptide-enriched diets may promote nitrogen absorption, whereas ω3-enriched diets reduce alterations in gut barrier function. The aim of this study was to assess the effectiveness of a peptide- and ω3-enriched diet on the metabolic response to injury and the gut barrier function in a model of prolonged catabolism in the rat.

Citrulline decreases hepatic endotoxin-induced injury in fructose-induced non-alcoholic liver disease: an ex vivo study in the isolated perfused rat liver.

Steatosis can sensitise the liver to various challenges and favour the development of non-alcoholic fatty liver disease (NAFLD). In this context, fructose feeding promotes endotoxin translocation from the gut, contributing to disease progression via an inflammatory process. Citrulline is protective against fructose-induced NAFLD; we hypothesised that this property might be related to its anti-inflammatory and antioxidative action against endotoxin-induced hepatic injuries.

Effects of a Carbohydrate-, Glutamine-, and Antioxidant-Enriched Oral Nutrition Supplement on Major Surgery-Induced Insulin Resistance: A Randomized Pilot Study.

Background: Insulin resistance after surgery hampers recovery. Oxidative stress is shown to be involved in the occurrence of postoperative insulin resistance. Preoperative carbohydrate-rich oral nutrition supplements reduce but do not prevent insulin resistance.

Oral arginine supplementation protects female mice from the onset of non-alcoholic steatohepatitis.

Dietary arginine (Arg) supplementation has been proposed to have positive effects on the development of liver diseases. In the present study, we investigate if an oral Arg supplementation in diet protects mice fed a fructose, fat and cholesterol enriched Western-style diet (WSD) from the development of non-alcoholic steatohepatitis (NASH). Female C57BL/6J mice were fed a liquid control diet or a liquid WSD ± Arg (2.