Current Opinion in Clinical Nutrition and Metabolic Care最新文献

Purpose of review: Iron is an essential trace element in human health that can be harmful at abnormal levels such as iron overload or deficiency. Measured iron status in the body can depend on health outcomes experienced by the individual and this can complicate its accurate assessment. This review will highlight recent research on iron assessment in the literature.

Recent findings: Research on iron assessment within the past 18 months included some common themes spanning new methods and biomarkers, as well as existing problems in assessing iron deficiency and overload. Heterogeneity in associations between inflammation and iron levels are reflected across different inflammatory biomarkers. New methods relevant to low- and high-resource settings may improve assessment in tissues with iron deficiency and overload. Consensus papers outlined best practices when using MRI to assess iron status. Outside of newer methods, traditional serum markers are the subject of a call for updated guidance when assessing iron status.

Summary: Research continues on the topic of iron assessment, underlying its complex metabolism in the body and resulting challenges in assessment. Current literature underscores progress to make iron assessment more accessible, improve existing methods, and update current assessment methods so they correspond with recent research to improve human health.

Purpose of review: With the shifts in society, healthcare and the profile of the malnourished individual, a re-consideration of the goal of nutritional risk screening is needed: screening for malnutrition, or screening for risk of malnutrition? In this review article, we reflect on the role of nutritional risk screening in relation to prevention and treatment of malnutrition.

Recent findings: Within the Global Leadership Initiative on Malnutrition (GLIM) Initiative, modified Delphi studies are currently being conducted to reach global consensus on the conceptual definition and operationalization of 'risk of malnutrition'. This is necessary because various studies have demonstrated that different nutritional screening tools identify different individuals, due to variability in screening tool criteria, which influences GLIM outcomes. Upon screening, three different situations can be distinguished: having risk factors for malnutrition without clear signs of presence of malnutrition, having mild signs of malnutrition (malnutrition in progress), or having obvious signs of malnutrition.

Summary: The outcomes of the studies on 'risk of malnutrition' will guide the screening step within the GLIM process, and will help professionals to make informed choices regarding screening policy and screening tool(s).

Purpose of review: Deficiencies in micronutrients persist as widespread global challenges, where supplementation remains a crucial therapeutic approach. This review aims to elucidate the intricate relationships between micronutrient supplementation - specifically iron, selenium (Se), and vitamin D (Vit D) - and gut microbiota composition, investigating their collective impact on host health and disease susceptibility.

Recent findings: Maintaining balanced iron levels is essential for gut microbiota equilibrium and host health, as both iron deficiency and excess disrupt gut bacterial balance, affecting colon health. Se supplementation can restore and improve the gut microbial balance, influencing health outcomes not only in the gut but also in areas such as neuroprotection in the brain, testicular health, and metabolic syndrome. Clinical and experimental models demonstrate that Vit D modulates the gut microbiome, enhancing anti-inflammatory effects, supporting metabolic health, and potentially reducing the risk of gut-related behavioral changes and diseases.

Summary: Findings of this review emphasize that balanced iron levels are essential for maintaining a healthy gut microbiota composition and underscore the beneficial effects of Se and Vit D in modulating the gut microbiome. The interactions between micronutrients and the gut microbiome are complex but may have a broad spectrum of health outcomes.

Purpose of review: The following article examines the rationale for an inflammation-first approach for diagnosing cachexia and how the current Global Leadership Initiative on Malnutrition (GLIM) framework may be adapted to facilitate this.

Recent findings: Recently, the GLIM have published guidance on the measurement of inflammation in the context of cachexia, advocating that C-reactive protein (CRP) should be utilized for quantification. The inclusion of a systemic inflammatory biomarker for the diagnosis of cachexia questions whether it may be more aptly considered a systemic inflammatory syndrome.

Summary: The current consensus of the GLIM is that cachexia is 'disease-related malnutrition with inflammation'. In line with this definition, the GLIM proposed a two-step diagnostic framework: screening for malnutrition using validated screening tools and then confirming the presence of disease-related malnutrition with phenotypic (nonvolitional weight loss, low BMI, and reduced muscle mass) and aetiologic criterion reduced food intake/assimilation, and inflammation or disease burden). The GLIM are to be commended for guidance on the measurement of systemic inflammation in their current proposal, given the relative importance to clinical outcomes in patients with cancer. However, the use of CRP is somewhat rudimentary and contrasts other cancer cachexia guidelines and contemporary clinical cancer research.

Purpose of review: With obesity affecting over one billion people globally, understanding and managing this complex condition is more crucial than ever. This review explores the emerging role of GLP-1 receptor agonists (GLP-1RA) in weight management, focusing on their impact on energy balance. It highlights the necessity of this investigation due to the limited knowledge on both the short-term and long-term implications of GLP-1RA on energy expenditure (EE) and energy intake (EI).

Recent findings: GLP-1RA, such as liraglutide and semaglutide, have shown significant efficacy in promoting weight loss by reducing appetite, cravings and consequently, EI. Newer medications such as tirzepatide have demonstrated even greater weight loss success. Emerging evidence also suggests potential effects on EE, which could explain the greater weight loss success achieved with GLP-1 RA rather than typical lifestyle changes. However, comprehensive data on the total impact of these drugs on energy balance remain limited.

Summary: The findings underscore the promising role of GLP-1RA in obesity management, particularly through mechanisms influencing both EI and EE. Future research should focus on systematically measuring all components of energy balance to fully elucidate the mechanisms of GLP-1RA and optimize their therapeutic use for personalized medicine.

Purpose of review: This review aims to explore the latest research investigating the effects of marine-derived long-chain n-3 polyunsaturated fatty acid (LCn-3 PUFA) supplementation on neuromuscular function in older adults.

Recent findings: Ageing results in a decline in skeletal muscle strength and mass. There is growing evidence that LCn-3 PUFA supplementation increases muscle strength and mass in healthy older adults, yet the mechanisms underlying these effects remain elusive. Recent studies investigating LCn-3 PUFA supplementation have demonstrated effects on neuromuscular function such as increases in the compound muscle action potential (M-wave) amplitude and surface electromyography alongside increases in muscular strength. Therefore, evidence suggests that LCn-3 PUFA may elicit a beneficial effect at the neuromuscular junction and possess neuroprotective properties in older adults.

Summary: LCn-3 PUFA supplementation may increase or maintain neuromuscular function throughout the ageing process. Further research is warranted to investigate the long-term effects LCn-3 PUFA supplementation on neuromuscular outcomes such as single motor unit properties and cortical/supraspinal networks, utilizing state-of-the-art techniques in neuromuscular physiology.

Purpose of review: Amino acids are critical to health, serving both as constituents of proteins and in signaling and metabolism. Amino acids are consumed as nutrients, supplements, and nutraceuticals. Much remains to be learned about amino acid function. Physiologically based pharmacokinetic and pharmacodynamic (PBPK-PD) modeling is an emerging tool for studying their complex biology. This review highlights recent PBPK-PD models developed to study amino acid physiology and metabolism and discusses their potential for addressing unresolved questions in the field.

Recent findings: PBPK-PD models provided several insights. They revealed the interplay between the mechanisms by which leucine governs skeletal muscle protein metabolism in healthy adults. The models also identified optimal dosing regimens of amino acid supplementation to treat sickle-cell disease and recurrent hypoglycemia, and to minimize drug side effects in seizure disorders. Additionally, they characterized the effects of novel anticancer drugs that seek to deprive cancer cells of amino acids. Future models may inform treatment strategies for sarcopenia, characterize distinctions between animal- and plant-based nutrition, and inform nutrient-drug interactions in Parkinson's disease.

Summary: PBPK-PD models are powerful tools for studying amino acid physiology and metabolism, with applications to nutrition, pharmacology, and their interplay.

Purpose of review: Critical care nutrition guidelines recommend provision of higher protein doses than recommended in health. These recommendations have been predominately based on lower quality evidence and physiological rationale that greater protein doses may attenuate the significant muscle loss observed in critically ill patients. This review discusses the mechanistic action of protein in the critically ill, details results from recent trials on health outcomes, discusses considerations for interpretation of trial results, and provides an overview of future directions.

Recent findings: Two recent large clinical trials have investigated different protein doses and the effect on clinical outcome. Important findings revealed potential harm in certain sub-groups of patients. This harm must be balanced with the potential for beneficial effects on muscle mass and physical function given that two recent systematic reviews with meta-analyses demonstrated attenuation of muscle loss with higher protein doses. Utilizing biological markers such as urea: creatinine ratio or urea levels may prove useful in monitoring harm from higher protein doses.

Summary: Future research should focus on prospectively investigating biological signatures of harm as well as taking into the consideration elements that will likely enhance the effectiveness of protein dose.

Purpose of review: This review highlights recent developments in understanding the role of dietary fibre and specific fibre types on risk and management of cardiometabolic disease with a focus on the causal pathways leading to cardiometabolic diseases, namely weight management, glycaemic control, and lipid levels, as well as the latest findings for cardiovascular disease outcomes such as coronary heart disease, stroke, and mortality. Evidence for mechanisms through gut microbiota are also briefly reviewed.

Recent findings: Dietary fibre intake is associated with improved weight management, the extent of which may depend on the subtype of dietary fibre. Overall dietary fibre intake reduces blood glucose and HbA1c, however soluble fibres may be particularly effective in reducing HbA1c, fasting blood glucose and blood lipids. Individual meta-analyses and umbrella reviews of observational studies on dietary fibre, as well as major fibre types, observed inverse associations with incident coronary heart disease, stroke, and mortality due to cardiovascular disease. As different types of fibres exerted different health benefits, fibre diversity (i.e. combinations of fibres) should be further investigated.

Summary: Dietary fibres improve both short-term and long-term cardiometabolic disease risk factors and outcomes, and thus should be on every menu.