Minerals and Sarcopenia in Older Adults: An Updated Systematic Review.

OBJECTIVE: This systematic review aims to reevaluate the role of minerals on muscle mass, muscle strength, physical performance, and the prevalence of sarcopenia in community-dwelling and institutionalized older adults. DESIGN: Systematic review. SETTING AND PARTICIPANTS: In March 2022, a systematic search was performed in PubMed, Scopus, and Web of Sciences using predefined search terms. Original studies on dietary mineral intake or mineral serum blood concentrations on muscle mass, muscle strength, and physical performance or the prevalence of sarcopenia in older adults (average age ≥65 years) were included. METHODS: Eligibility screening and data extraction was performed by 2 independent reviewers. Quality assessment was performed with the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. Risk of bias was evaluated using the Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) tool. RESULTS: From the 15,622 identified articles, a total of 45 studies were included in the review, mainly being cross-sectional and observational studies. Moderate quality of evidence showed that selenium (n = 8) and magnesium (n = 7) were significantly associated with muscle mass, strength, and physical performance as well as the prevalence of sarcopenia. For calcium and zinc, no association could be found. For potassium, iron, sodium, and phosphorus, the association with sarcopenic outcomes remains unclear as not enough studies could be included or were nonconclusive (low quality of evidence). CONCLUSIONS AND IMPLICATIONS: This systematic review shows a potential role for selenium and magnesium on the prevention and treatment of sarcopenia in older adults. More randomized controlled trials are warranted to determine the impact of minerals on sarcopenia in older adults.

Nutritional problems of patients with COVID-19 receiving dietetic treatment in primary care.

BACKGROUND: The nutritional problems of patients who are hospitalised for COVID-19 are becoming increasingly clear. However, a large group of patients have never been hospitalised and also appear to experience persistent nutritional problems. The present study describes the nutritional status, risk of sarcopaenia and nutrition-related complaints of patients recovering from COVID-19 receiving dietetic treatment in primary care. METHODS: In this retrospective observational study, data were collected during dietetic treatment by a primary care dietitian between April and December 2020. Both patients who had and had not been admitted to the hospital were included at their first visit to a primary care dietitian. Data on nutritional status, risk of sarcopaenia and nutrition-related complaints were collected longitudinally. RESULTS: Data from 246 patients with COVID-19 were collected. Mean ± SD age was 57 ± 16 years and 61% of the patient population was female. At first consultation, two thirds of patients were classified as overweight or obese (body mass index >25 kg m-2 ). The majority had experienced unintentional weight loss because of COVID-19. Additionally, 55% of hospitalised and 34% of non-hospitalised patients had a high risk of sarcopaenia. Most commonly reported nutrition-related complaints were decreased appetite, shortness of breath, changed or loss of taste and feeling of being full. Nutrition-related complaints decreased after the first consultation, but remained present over time. CONCLUSIONS: In conclusion, weight changes, risk of sarcopaenia and nutrition-related complaints were prevalent in patients with COVID-19, treated by a primary care dietitian. Nutrition-related complaints improved over time, but remained prevalent until several months after infection.

Optimization of Protocols Using Neuromuscular Electrical Stimulation for Paralyzed Lower-Limb Muscles to Increase Energy Expenditure in People With Spinal Cord Injury.

OBJECTIVE: The aim of this study was to evaluate whether using surface neuromuscular electrical stimulation (NMES) for paralyzed lower-limb muscles results in an increase in energy expenditure and whether the number of activated muscles and duty cycle affect the potential increase. DESIGN: This was a cross-sectional study. RESULTS: Energy expenditure during all NMES protocols was significantly higher than the condition without NMES (1.2 ± 0.2 kcal/min), with the highest increase (+51%; +0.7 kcal/min, 95% confidence interval, 0.3-1.2) for the protocol with more muscles activated and the duty cycle with a shorter rest period. A significant decrease in muscle contraction size during NMES was found with a longer stimulation time, more muscles activated, or the duty cycle with a shorter rest period. CONCLUSION: Using NMES for paralyzed lower-limb muscles can significantly increase energy expenditure compared with sitting without NMES, with the highest increase for the protocol with more muscles activated and the duty cycle with a shorter rest period. Muscle fatigue occurred significantly with the more intense NMES protocols, which might cause a lower energy expenditure in a longer protocol. Future studies should further optimize the NMES parameters and investigate the long-term effects of NMES on weight management in people with SCI.

Minerals and Sarcopenia; The Role of Calcium, Iron, Magnesium, Phosphorus, Potassium, Selenium, Sodium, and Zinc on Muscle Mass, Muscle Strength, and Physical Performance in Older Adults: A Systematic Review.

INTRODUCTION: Minerals may contribute to prevent and treat sarcopenia, the age-related loss of muscle mass, muscle strength, and physical performance. So far, there is no comprehensive review on the impact of minerals on sarcopenia outcomes. The aim of this systematic review is to evaluate the role of calcium, iron, magnesium, phosphorus, potassium, selenium, sodium, and zinc on muscle mass, muscle strength, and physical performance in older adults. METHODS: A systematic search was conducted between March 2016 and July 2016, in the PubMed database using predefined search terms. Articles on the role of dietary mineral intake or mineral serum concentrations on muscle mass, muscle strength, physical performance, and/or the prevalence of sarcopenia in healthy or frail older adults (average age ≥ 65 years) were selected. Only original research publications were included. The search and data extraction were conducted in duplicate by 2 independent researchers. The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement was followed in constructing this systematic review. The Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies was used to evaluate the quality of the selected articles. RESULTS: From the 3346 articles found, a total of 10 studies met the inclusion criteria. Observational studies showed that serum selenium (n = 1) and calcium intake (n = 1) were significantly associated with muscle mass, and magnesium (n = 1), selenium (n = 1), iron (n = 1), and zinc (n = 1) intake were significantly and positively associated with physical performance in older adults. Furthermore, magnesium (n = 2), selenium (n = 2), calcium (n = 2), and phosphorus (n = 1) intake were associated with the prevalence of sarcopenia. Magnesium supplementation improved physical performance based on one randomized controlled trial. No studies on the role of sodium or potassium on muscle mass, muscle strength, or physical performance were found. CONCLUSION: Minerals may be important nutrients to prevent and/or treat sarcopenia. Particularly, magnesium, selenium, and calcium seem to be most promising. Most of the included studies, however, were observational studies. Therefore, more randomized controlled trials are needed to elucidate the potential benefits of mineral intake to prevent and/or treat sarcopenia and support healthy aging.

Protein Kinetics and Metabolic Effects Related to Disease States in the Intensive Care Unit.

Evaluating protein kinetics in the critically ill population remains a very difficult task. Heterogeneity in the intensive care unit (ICU) population and wide spectrum of disease processes creates complexity in assessing protein kinetics. Traditionally, protein has been delivered in the context of total energy. Focus on energy delivery has recently come into question, as the importance of supplemental protein in patient outcomes has been shown in several recent trials. The ICU patient is prone to catabolism, immobilization, and impaired immunity, which is a perfect storm for massive loss of lean body tissue with a unidirectional flow of amino acids from muscle to immune tissue for immunoglobulin production, as well as liver for gluconeogenesis and acute phase protein synthesis. The understanding of protein metabolism in the ICU has been recently expanded with the discovery of how the mammalian target of rapamycin complex 1 is regulated. The concept of "anabolic resistance" and identifying the quantity of protein required to overcome this resistance is gaining support among critical care nutrition circles. It appears that a minimum of at least 1.2 g/kg/d with levels up to 2.0 g/kg/d of protein or amino acids appears safe for delivery in the ICU setting and may yield a better clinical outcome.

Protein Delivery in the Intensive Care Unit: Optimal or Suboptimal?

Emerging evidence suggests that exogenous protein/amino acid supplementation has the potential to improve the recovery of critically ill patients. After a careful review of the published evidence, experts have concluded that critically ill patients should receive up to 2.0-2.5 g/kg/d of protein. Despite this, however, recent review of current International Nutrition Survey data suggests that protein in critically ill patients is underprescribed and grossly underdelivered. Furthermore, the survey suggests that most of protein administration comes from enteral nutrition (EN) despite the availability of products and protocols that enhance the delivery of protein/amino acids in the intensive care unit (ICU) setting. While future research clarifies the dose, timing, and composition for exogenous protein administration, as well as identification of patients who will benefit the most, ongoing process improvement initiatives should target a concerted effort to increase protein intake in the critically ill. This assertion follows from the notion that current patients are possibly being harmed while we wait for confirmatory evidence. Further research should also develop better tools to enable bedside practitioners to monitor optimal or adequate protein intake for individual patients. Finally, exploring the effect of combining adequate protein delivery with early mobility and/or resistance exercise in the ICU setting has the greatest potential for improving the functional outcomes of survivors of critical illness and warrants further study.

A high whey protein-, leucine-, and vitamin D-enriched supplement preserves muscle mass during intentional weight loss in obese older adults: a double-blind randomized controlled trial.

BACKGROUND: Intentional weight loss in obese older adults is a risk factor for muscle loss and sarcopenia. OBJECTIVE: The objective was to examine the effect of a high whey protein-, leucine-, and vitamin D-enriched supplement on muscle mass preservation during intentional weight loss in obese older adults. DESIGN: We included 80 obese older adults in a double-blind randomized controlled trial. During a 13-wk weight loss program, all subjects followed a hypocaloric diet (-600 kcal/d) and performed resistance training 3×/wk. Subjects were randomly allocated to a high whey protein-, leucine-, and vitamin D-enriched supplement including a mix of other macro- and micronutrients (150 kcal, 21 g protein; 10×/wk, intervention group) or an isocaloric control. The primary outcome was change in appendicular muscle mass. The secondary outcomes were body composition, handgrip strength, and physical performance. Data were analyzed by using ANCOVA and mixed linear models with sex and baseline value as covariates. RESULTS: At baseline, mean ± SD age was 63 ± 5.6 y, and body mass index (in kg/m(2)) was 33 ± 4.4. During the trial, protein intake was 1.11 ± 0.28 g · kg body weight(-1) · d(-1) in the intervention group compared with 0.85 ± 0.24 g · kg body weight(-1) · d(-1) in the control group (P < 0.001). Both intervention and control groups decreased in body weight (-3.4 ± 3.6 kg and -2.8 ± 2.8 kg; both P < 0.001) and fat mass (-3.2 ± 3.1 kg and -2.5 ± 2.4 kg; both P < 0.001), with no differences between groups. The 13-wk change in appendicular muscle mass, however, was different in the intervention and control groups [+0.4 ± 1.2 kg and -0.5 ± 2.1 kg, respectively; ß = 0.95 kg (95% CI: 0.09, 1.81); P = 0.03]. Muscle strength and function improved over time without significant differences between groups. CONCLUSION: A high whey protein-, leucine-, and vitamin D-enriched supplement compared with isocaloric control preserves appendicular muscle mass in obese older adults during a hypocaloric diet and resistance exercise program and might therefore reduce the risk of sarcopenia. This trial was registered at the Dutch Trial Register (http://www.trialregister.nl) as NTR2751.

Preservation of autophagy should not direct nutritional therapy.

PURPOSE OF REVIEW: Recent reports in the literature have proposed that forced mandatory feeding should be avoided in the first week of critical illness to preserve autophagy, in order to maximize responses to oxidative stress, preserve organ function, and improve outcomes. RECENT FINDINGS: Autophagy is a well recognized physiologic process that serves a housekeeping role for the cell to eliminate large protein aggregates and as a survival mechanism in starvation for generating energy (ATP) and promoting protein synthesis to maintain cell structure. In the critical care setting, autophagy may have important roles in modulating immune function, fighting infection, and preventing organ failure. The effect of feeding on autophagy is complex, poorly understood, and difficult to predict. SUMMARY: The argument to withhold feeding to preserve autophagy is poorly substantiated and should not interfere with the delivery of early enteral nutrition to the critically ill patient in that first week following admission to the ICU.