Current Opinion in Clinical Nutrition and Metabolic Care最新文献

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: The purpose of this review is to critically evaluate the effects of vitamin D on muscle mass and physical/muscle function in middle-aged and older adults, based on recent human studies, including cross-sectional, observational, and intervention studies. Vitamin D, beyond its well established role in bone health, has shown potential in influencing muscle physiology, making it a nutrient of interest in the context of sarcopenia and related chronic conditions.

Recent findings: The review states how vitamin D affects muscle function, emphasizing its role in muscle cell proliferation, differentiation, and key signaling pathways. Additionally, the review of recent human studies revealed an inconsistent relationship between vitamin D and sarcopenia and related indices, with mixed results regarding muscle mass and strength. Variability in supplementation dose, duration, and baseline 25-hydroxyvitamin D levels may contribute to these inconsistencies.

Summary: While animal studies indicate vitamin D's effectiveness in muscle growth, cross-sectional, observational, and intervention studies do not show clear benefits of maintaining efficient vitamin D levels on muscle mass or function in humans. Although vitamin D impacts muscle health, it is insufficient alone, emphasizing the need for a multifaceted approach to sarcopenia prevention and management.

Purpose of review: This review aims to summarize the latest publications on vitamin D focused on critically ill patients.

Recent findings: Vitamin D deficiency is common in critically ill patients (children and adults) and associated with a higher risk for mortality and morbidity as well as sepsis, acute respiratory failure, acute renal failure and prolonged ICU stay. As it is an inexpensive substance with a wide safety margin, acute treatment in form of a loading dose in addition to ongoing maintenance therapy is an interesting option in the ICU. The potential benefit of acute native (biologically inactive) vitamin D treatment has not fully been answered but even a small survival benefit demonstrable in very large analyses could be relevant to critical care. To date, less than 5000 patients cumulative have been enrolled in randomized controlled trials concerning vitamin D, with substantial heterogeneity in trial design regarding population (with or without deficiency, coronavirus disease 2019, different age groups, underlying illnesses), metabolite, dosing, outcome, and more.

Summary: More research is needed, but vitamin D supplementation represents a simple intervention with an excellent safety profile. As adequate vitamin D is essential to the health of multiple organ systems, rapid normalization of deficiency states could translate to benefits across the wide range of diagnoses and organ dysfunctions experienced in the ICU setting. As a minimum, we recommend administering the standard daily dose of vitamin D3 in the critically ill patient.

Purpose of review: This review aims to explore the latest research investigating the effects of marine-derived long-chain n -3 polyunsaturated fatty acid (LC n -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 LC n -3 PUFA supplementation increases muscle strength and mass in healthy older adults, yet the mechanisms underlying these effects remain elusive. Recent studies investigating LC n -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 LC n -3 PUFA may elicit a beneficial effect at the neuromuscular junction and possess neuroprotective properties in older adults.

Summary: LC n -3 PUFA supplementation may increase or maintain neuromuscular function throughout the ageing process. Further research is warranted to investigate the long-term effects LC n -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: Acute kidney injury (AKI) is common in hospitalized patients and is independently associated with morbidity and mortality. Moreover, AKI increases the risk of chronic kidney disease, which is a major healthcare problem. Currently, no single therapy has been proven to be effective in preventing AKI. The role of amino acids in the context of kidney function and AKI prevention has been controversial and most of the evidence is available from nutritional studies. However, knowledge of amino acids in recruiting renal functional reserve and their potential role to protect renal function under stress has recently expanded.

Recent findings: The nephroprotective effects of amino acids were first postulated in 1973. Recently, this strategy gained renewed interest and has been more extensively studied, reintroducing their use in clinical situations characterized by a high incidence of AKI. Intravenous amino acids administration for kidney protection is now supported by a large multinational randomized double-blind controlled trial in cardiac surgery and by experimental and observational data. All such data support the rationale for a biologically and clinically important nephroprotective effect.

Summary: The infusion of amino acids was recently found to reduce the incidence of AKI in cardiac surgery patients and surgical patients. This strategy for the protection of renal function is supported by a multicenter, international, double-blind randomized trial, with a huge potential for additional application in several clinical fields. Several mechanisms of action support the robustness of these findings and are summarized in this manuscript.

Purpose of the review: To assess the quality of recently published (18 months from date of article request) randomized trials/systematic reviews of such trials that addressed the use of nutritional support in critically ill patients.

Recent findings: Eligible papers were published between October 1, 2022 and April 7, 2024, only enrolled adults, described a comparison of a nutritional intervention to something else, and reported a clinically relevant outcome. Thirteen randomized trials and four systematic reviews of randomized trials were identified. Quality was assessed by determining the risks of bias of each trial. Two of these trials were at low risk of bias, six were rated as having some concern(s) about bias, and five were at high risk of bias. The four systematic reviews included 55 randomized trials; four were at low risk, 31 had some concerns, and 20 were at high risk. No randomized trial comparing nutritional support to a true control (no nutritional support) was identified in this search; seven older trials, all small and containing risks of bias, failed to demonstrate any consistent differences in clinical outcomes.

Summary: The quality of the trials underlying the use of nutritional support in the intensive care unit is not very high.