Current Opinion in Clinical Nutrition and Metabolic Care最新文献

Purpose of review: Children with linear growth faltering refractory to nutritional management show evidence of environmental enteropathy, which may compromise nutrient availability. Protein could be particularly affected, due to the possibility of sub-optimal digestibility and/or increase in requirement for immune response. This increase in protein requirement along with poor intake could potentially lead to increased breakdown of body protein sources and in turn a depleted protein state. The present review focuses on protein status in children at risk of linear growth faltering and environmental enteropathy. One pig study is also presented.

Recent findings: There is consistent evidence of low circulating essential and conditionally essential amino acids, in children. One study showed no difference in protein synthesis/breakdown, and fat free mass (FFM) in children at risk of linear growth faltering and environmental enteropathy. Weanling pigs exposed to nutrient deprivation showed a decrease in plasma albumin, with a slower rate of weight and length accretion, and a lower FFM.

Summary: These findings emphasize the need for improving intake of high-quality protein in children living in regions with a high prevalence of environmental enteropathy, with careful studies of the effect on growth rate and protein status.

Purpose of review: We provided an updated overview of recent data on the value of nutritional therapy in the management of chronic wounds in older adults.

Recent findings: In the last years, advances in this area were limited, but new data suggest considering nutritional care (screening and assessment of malnutrition and nutritional interventions) also in patients with chronic wounds other than pressure ulcers, namely venous leg and diabetic foot ulcers, as in these patients, nutritional derangements can be present despite overweight/obesity and their management is beneficial.

Summary: Chronic wounds are wounds in which the process of repair does not progress normally due to a disruption in one or more of the healing phases. Nutritional therapy is aimed at recovering the process of repair. General principles of nutritional care in geriatrics apply to these patients but disease-specific recommendations are available, particularly for pressure ulcers. Interventions should address nutritional status, comorbidities, hydration and should provide key nutrients playing an active role in the healing process (arginine, zinc, and antioxidants) but always within the context of an individual care plan addressing patients requirements, particularly protein needs. Further evidence of efficacy in vascular and diabetic foot ulcers is warranted.

Purpose of review: Many studies using metabolomics have tried to unravel the metabolic signature of obesity and understand the pathophysiology of this complex and heterogeneous disease. Circulating levels of the amino acid glutamate have been consistently associated with obesity and more specifically with measurements of abdominal fat accumulation. The purpose of this narrative review is to highlight recent studies documenting this association.

Recent findings: Circulating glutamate concentrations have been positively correlated with measurements of central fat accumulation such as waist circumference and visceral adipose tissue area. Moreover, elevated glutamate levels have been linked to a higher prevalence of type 2 diabetes, cardiovascular diseases and nonalcoholic fatty liver disease. The association with adiposity is detected in early life, and genetic predisposition does not appear as a major driver. Glutamate levels reflect in vivo synthesis rather than dietary intake. However, interventions generating metabolic improvements such as incretin receptor agonist treatment or dietary improvements may reduce plasma levels of this amino acid.

Summary: Recent findings confirm the consistent association between circulating glutamate and abdominal obesity and its cardiometabolic complications. The pathophysiological pathways underlying this phenomenon are still unclear. Furthermore, studies are needed to establish the usefulness of this analyte as a biomarker of abdominal obesity.

Purpose of review: Stable isotope methods have been used for many years to assess whole body protein and amino acid kinetics in critically ill patients. In recent years, new isotope approaches and tracer insights have been developed. The tracer pulse approach has some advantages above the established primed-continuous tracer infusion approach because of the high amount of metabolic information obtained, easy applicability, and low tracer costs. Effects of disease severity and sex on amino acid kinetics in ICU patients will also be addressed.

Recent findings: Current knowledge was synthesized on specific perturbations in amino acid metabolism in critically ill patients, employing novel methodologies such as the pulse tracer approach and computational modeling. Variations were evaluated in amino acid production and linked to severity of critical illness, as measured by SOFA score, and sex. Production of the branched-chain amino acids (BCAAs), glutamine, tau-methylhistidine and hydroxyproline were elevated in critical illness, likely related to increased transamination of the individual BCAAs or increased breakdown of proteins. Citrulline production was reduced, indicative of impaired gut mucosa function. Sex and disease severity independently influenced amino acid kinetics in ICU patients.

Summary: Novel tracer and computational approaches have been developed to simultaneously measure postabsorptive kinetics of multiple amino acids that can be used in critical illness. The collective findings lay the groundwork for targeted individualized nutritional strategies in ICU settings aimed at enhancing patient outcomes taking into account disease severity and sex.

Purpose of review: Casein glycomacropeptide (CGMP) is a milk-derived bioactive sialyated phosphorylated peptide with distinctive nutritional and nutraceutical properties, produced during the cheese making process. It comprises 20-25% of total protein in whey products. CGMP is low in phenylalanine (Phe) and provides an alternative to Phe-free amino acids as a source of protein equivalent for patients with phenylketonuria (PKU). The amino acid sequence of CGMP is adapted by adding the amino acids histidine, leucine, tyrosine, arginine and tryptophan to enable its suitability in PKU. CGMP has potential antibacterial, antioxidative, prebiotic, remineralizing, digestion /metabolism and immune-modulating properties. The aim of this review is to assess the evidence for the role of CGMP in the management of PKU.

Recent findings: In PKU, there is no agreement concerning the amino acid composition of CGMP protein substitutes and consequently the nutritional composition varies between products. Although there is evidence in patients or animal models that CGMP has possible beneficial effects on gut microbiota and bone health, the results are inconclusive. Data on kinetic advantage is limited. Most studies report an increase in blood Phe levels with CGMP. Appropriate adaptations and reduction of dietary Phe intake should be made to compensate for the residual Phe content of CGMP, particularly in children. Data from short term studies indicate improved palatability of CGMP when compared to Phe-free amino acids.

Summary: In PKU, CGMP with supplementary amino acids, offers a safe low Phe nitrogen source. Current scientific evidence is unconvincing about its bioactive advantage in PKU. Further longitudinal research is necessary.

Purpose of review: Calcific aortic valve disease (CAVD), the most common cause of aortic stenosis (AS), is characterized by slowly progressive fibrocalcific remodelling of the valve cusps. Once symptomatic, severe AS is associated with poor survival unless surgical or transcatheter valve replacement is performed. Unfortunately, no pharmacological interventions have been demonstrated to alter the natural history of CAVD. Lipoprotein(a) [Lp(a)], a low-density lipoprotein-like particle, has been implicated in the pathophysiology of CAVD.

Recent findings: The mechanisms by which Lp(a) results in CAVD are not well understood. However, the oxidized phospholipids carried by Lp(a) are considered a crucial mediator of the disease process. An increasing number of studies demonstrate a causal association between plasma Lp(a) levels and frequency of AS and need for aortic valve replacement, which is independent of inflammation, as measured by plasma C-reactive protein levels. However, not all studies show an association between Lp(a) and increased progression of calcification in individuals with established CAVD.

Summary: Epidemiologic, genetic, and Mendelian randomization studies have collectively suggested that Lp(a) is a causal risk factor for CAVD. Whether Lp(a)-lowering can prevent initiation or slow progression of CAVD remains to be demonstrated.

Purpose of review: This study aims to review recent evidence (2022-2023) on the role of diet in promoting healthy aging in older adults.

Recent findings: Current evidence of diet and healthy aging is limited to epidemiological studies. A healthy diet is beneficial for individual domains of intrinsic capacity, that is, cognition, locomotion, vitality, psychological, and/or sensory functions, with sex-specific differences reported. Only a few studies used the multidimensional concept of intrinsic capacity as an outcome. This review supports that a healthy diet for older adults consists of plenty of plant-based foods, adequate protein-rich foods, and healthy fats. Next to quantity, improving the quality and variety within food groups play a role in optimizing health. Data on the associations between adherence to national food-based dietary guidelines and intrinsic capacity are scarce.

Summary: A healthy diet, centered on plant-based foods, adequate protein-rich foods and healthy fats, potentially promotes healthy aging. Future studies may evaluate the association between adherence to healthy dietary patterns (particularly national food-based dietary guidelines) and the multidimensional concept of intrinsic capacity, with consideration of sex-specific differences. Clinical trials are warranted to inform the causal effects of diet and outcomes related to intrinsic capacity.

Purpose of review: Dementia is a growing concern and underscores the urgent need for effective preventive measures targeting modifiable risk factors. Nutrition is a key player in the onset and progression of inflammation and cognitive decline. This review provides a comprehensive overview of the effects of different dietary patterns, vitamins and nutrients for preventing cognitive decline, mainly among healthy individuals and those with mild cognitive impairment.

Recent findings: The Mediterranean diet, omega-3 long-chain polyunsaturated fatty acids and B vitamins are the most investigated, with evidence supporting protection against cognitive decline among older adults varying across studies. More recent interventions examined in this review, such as MIND Diet, are promising with positive results, but further research is needed to conclusively establish their efficacy. It is also crucial to consider complete lifestyle as physical activity for preventing cognitive decline.

Summary: Definitive conclusions are difficult to draw. Future studies should adopt a comprehensive approach and focus on multinutrient strategies and whole diets.

Purpose of review: Recent findings in the influence of dietary patterns, dairy products, beverages and microbiota composition and function on bone health are reviewed and discussed.

Recent findings: Evidence is accumulating on the increased risk of fracture in individuals following a vegan diet. Meta-analysis of randomized controlled trials indicates a favourable, though of low amplitude, effect of dairy products on bone mass accrual during childhood and adolescence. Though mostly based on results from observational studies, it seems that dairy product consumption, particularly fermented dairy products, is associated with a lower risk of hip fracture. Regular green tea drinkers may have a lower fracture risk than tea abstainers. Magnesium intake is beneficial for bone health. Prune supplements prevents bone loss in untreated postmenopausal women. This seems to be associated with modification of gut microbiota.

Summary: This information should help the medical practitioners facing questions from their patients on how to protect bone health through nutrition.