Effects of branched amino acids supplementation in malnourished elderly with catabolic status

The effect of dose, frequency, and timing of protein supplementation on muscle mass in older adults: A systematic review and meta-analysis

Protein supplementation has shown to improve muscle mass in older adults. However, its effect may be influenced by supplementation dose, frequency and timing. This systematic review aimed to assess the effect of dose, frequency and timing of protein supplementation on muscle mass in older adults. Five databases were systematically searched from inception to 14 March 2023, for randomised controlled trials investigating the effect of protein supplementation on muscle mass in adults aged ≥65 years. Random effects meta-analyses were performed, stratified by population. Subgroups were created for dose (≥30 g, <30 g/day), frequency (once, twice, three times/day) and timing of supplementation (at breakfast, breakfast and lunch, breakfast and dinner, all meals, between meals). Heterogeneity within and between subgroups was assessed using I2 and Cochran Q statistics respectively. Thirty-eight articles were included describing community-dwelling (28 articles, n=3204, 74.6±3.4 years, 62.8 % female), hospitalised (8 articles, n=590, 77.0±3.7 years, 50.3 % female) and institutionalised populations (2 articles, n=156, 85.7±1.2 years, 71.2 % female). Protein supplementation showed a positive effect on muscle mass in community-dwelling older adults (standardised mean difference 0.116; 95 % confidence interval 0.032-0.200 kg, p=0.007, I2=15.3 %) but the effect did not differ between subgroups of dose, frequency and timing (Q=0.056, 0.569 and 3.084 respectively, p>0.05). Data including hospitalised and institutionalised populations were limited. Protein supplementation improves muscle mass in community-dwelling older adults, but its dose, frequency or timing does not significantly influence the effect.

Impact of food-based fortification on nutritional outcomes and acceptability in older adults: systematic literature review

Background

"Do it yourself" (DIY) food-based fortification involves adding fortificants into everyday foods. It is a flexible solution that allows older people with reduced appetite to meet their nutritional needs.

Objectives

The aims of the systematic review are (a) to describe DIY fortified recipes, (b) to evaluate their acceptability, and (c) to evaluate whether they are effective levers to improve nutritional outcomes in older people.

Methods

A systematic search of 3 databases (Web of Science, PubMed, Scopus, last searched on January 2022) was undertaken. Main eligibility criteria include older adults aged ≥60 years living at home, in an institution or in hospital. Studies carried out for a specific medical condition or targeting only micronutrient fortification were excluded. After reviewing all titles/abstracts then full-text papers, key data were extracted and synthesized narratively. The quality of included studies was assessed using Kmet et al.

Results

Of 21,493 papers extracted, 44 original studies were included (3,384 participants), with 31 reporting nutritional outcomes, 3 reporting acceptability outcomes and 10 reporting both nutritional and acceptability outcomes. The review highlighted a wide variety of DIY fortified recipes, with additional energy ranging from 23 to 850 kcal/d (M = 403; SE = 62) and/or protein ranging from 4 to 40 g/d (M = 19; SE = 2). Compared to a standard diet, DIY fortification seems to be a valuable strategy for increasing energy and protein intake in older people. However, no strong evidence was observed on the nutritional status.

Implication for future

Further acceptability studies are crucial to ensure that DIY fortified foods are palatable and thus have a significant impact on the nutritional status. In addition, it would be useful for studies to better describe DIY recipes. This information would result in a better understanding of the factors that maximize the impact of DIY fortification on nutritional outcomes. Study registration: PROSPERO no. CRD42021244689.Systematic review registration: PROSPERO: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021244689.

Large-scale metabolome analysis reveals dynamic changes of metabolites during foxtail millet grain filling

Compared with traditional staple crops, foxtail millet grain is rich in nutrition and beneficial to human health. Foxtail millet is also tolerance to various abiotic stresses, including drought, making it a good plant for growing in barren land. The study on the composition of metabolites and its dynamics changes during grain development is helpful to understand the process of foxtail millet grain formation. In our study, metabolic and transcriptional analysis were used to uncover the metabolic processes that could influence grain filling in foxtail millet. A total of 2104 known metabolites, belonging to 14 categories, were identified during grain filling. Functional analysis of DAMs and DEGs revealed a stage-specific metabolic properties in foxtail millet grain filling. Some important metabolic processes, such as flavonoid biosynthesis, glutathione metabolism, linoleic acid metabolism, starch and sucrose metabolism and valine, leucine and isoleucine biosynthesis were co-mapped for DEGs and DAMs. Thus, we constructed a gene-metabolite regulatory network of these metabolic pathways to explain their potential functions during grain filling. Our study showed the important metabolic processes during grain filling and focused on the dynamic changes of related metabolites and genes at different stages, which provided a reference for us to better understand and improve foxtail millet grain development and yield.

Towards developing a Core Outcome Set for malnutrition intervention studies in older adults: a scoping review to identify frequently used research outcomes

Purpose

To conduct a scoping review to provide a systematic overview of outcomes used in nutritional intervention studies focused on the treatment of protein-energy malnutrition in older adults.

Methods

A systematic search of four electronic databases (Medline, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials (CENTRAL) was performed to retrieve randomized controlled trials (RCTs), published until March 9, 2020, that evaluated the effect of nutritional interventions to treat protein-energy malnutrition in older adults and those at risk for malnutrition. Two authors screened titles, abstracts and full texts independently. One author extracted data that were cross-checked by another author.

Results

Sixty-three articles reporting 60 RCTs were identified. Most frequently used outcomes included body weight/body mass index (75.0% of RCTs), dietary intake (61.7%), functional limitations (48.3%), handgrip strength (46.7%), and body circumference (40.0%). The frequencies differed by setting (community, hospital and long-term care). For some outcomes there was a preferred assessment method (e.g., Barthel index for functional limitations), while for other outcomes (e.g., functional performance) a much greater variation was observed.

Conclusion

A large variation in outcomes, not only across but also within settings, was identified in nutritional intervention studies in malnourished older adults and those at risk. Furthermore, for many outcomes there was a large variation in the used assessment method. These results highlight the need for developing a Core Outcome Set for malnutrition intervention studies in older adults to facilitate future meta-analyses that may enhance our understanding on the effectiveness of treatment.

Factors influencing the efficacy of nutritional interventions on muscle mass in older adults: a systematic review and meta-analysis

CONTEXT

Nutritional interventions stimulate muscle protein synthesis in older adults. To optimize muscle mass preservation and gains, several factors, including type, dose, frequency, timing, duration, and adherence have to be considered.

OBJECTIVE

This systematic review and meta-analysis aimed to summarize these factors influencing the efficacy of nutritional interventions on muscle mass in older adults.

DATA SOURCES

A systematic search was performed using the electronic databases MEDLINE, Embase, CINAHL, Cochrane Central Register of Controlled Trials, and SPORTDiscus from inception date to November 22, 2017, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria included randomized controlled trials, mean or median age ≥65 years, and reporting muscle mass at baseline and postintervention. Exclusion criteria included genetically inherited diseases, anabolic drugs or hormone therapies, neuromuscular electrical stimulation, chronic kidney disease, kidney failure, neuromuscular disorders, and cancer.

DATA EXTRACTION

Extracted data included study characteristics (ie, population, sample size, age, sex), muscle mass measurements (ie, method, measure, unit), effect of the intervention vs the control group, and nutritional intervention factors (ie, type, composition, dose, duration, frequency, timing, and adherence).

DATA ANALYSIS

Standardized mean differences and 95%CIs were calculated from baseline to postintervention. A meta-analysis was performed using a random-effects model and grouped by the type of intervention.

CONCLUSIONS

Twenty-nine studies were included, encompassing 2255 participants (mean age, 78.1 years; SD, 2.22). Amino acids, creatine, β-hydroxy-β-methylbutyrate, and protein with amino acids supplementation significantly improved muscle mass. No effect was found for protein supplementation alone, protein and other components, and polyunsaturated fatty acids. High interstudy variability was observed regarding the dose, duration, and frequency, coupled with inconsistency in reporting timing and adherence. Overall, several nutritional interventions could be effective to improve muscle mass measures in older adults. Because of the substantial variability of the intervention factors among studies, the optimum profile is yet to be established.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018111306.

Systematic review and meta-analysis of the effect of protein and amino acid supplements in older adults with acute or chronic conditions

The loss of lean body mass, muscle strength and physical function causes significant problems in older adults. Protein and amino acid supplements can preserve muscle strength but the effect on function is variable. We conducted a systematic literature review and meta-analysis to investigate the effect of protein and amino acid supplementation on fat-free mass, muscle strength and physical function in malnourished, frail, sarcopenic, dependent or elderly with acute or chronic conditions, with or without rehabilitation exercise. Databases searched included Medline, BIOSIS, CINAHL, Cochrane Library, EBM Reviews, Embase, Pre-Medline, ProQuest, PubMed and Scopus. Retrieved articles were assessed by two reviewers using the Cochrane Risk of Bias (ROB) Tool. In all, thirty nine randomised controlled trails (n 4274) were included. The studies used a range of protein or essential amino acid (EAA) supplements in a variety of settings, including hospital, community and long-term care. Only seven studies had low ROB and no effect of supplementation was found on any outcomes. Analysis of all thirty-nine studies suggest protein and EAA supplements may improve fat-free mass, muscle strength and physical function (standardised mean difference 0·21-0·27, all P<0·005), but significant heterogeneity and ROB was evident. Predetermined subgroup analysis found undernourished elderly benefitted most; EAA were the most effective supplements and small beneficial effects were seen without rehabilitation exercise. The high heterogeneity and few studies with low ROB limits the conclusions and more high quality studies are needed to determine the best nutritional strategies for the maintenance of strength and function with increasing age.

BCAT1促进肿瘤发生发展的研究进展

支链氨基酸转移酶1(branched-chain amino acid transaminase 1, BCAT1)是催化支链氨基酸代谢的关键酶. 国内外研究已证实BCAT1在多种恶性肿瘤中呈现高表达, 并提示与肿瘤细胞增殖、转移及侵袭密切相关. 本文拟就BCAT1的理化性质、生物学功能及其与肿瘤发生、发展的相关研究进行简要综述, 为进一步研究BCAT1与恶性肿瘤的关系提供线索.

Effects of leucine-rich protein supplements on anthropometric parameter and muscle strength in the elderly: a systematic review and meta-analysis

OBJECTIVE

The primary objective of the present systematic review and meta-analysis was to synthesize the available literature relating to leucine supplementation in the elderly with respect to its effects on anthropometrical parameters and muscle strength. The secondary aim was to perform a selective subgroup analysis when possible differentiating between healthy and sarcopenic subjects.

METHODS

Literature search was performed using the electronic databases MEDLINE, EMBASE, SportDiscus, and the Cochrane Central Register of trials with restrictions to randomized controlled trials or studies following a cross-over design. Parameters taken into account were body weight, body mass index, lean body mass, fat mass, percentage of body fat, hand grip strength, and knee extension strength. Moreover, biomarkers of glucose metabolism (fasting glucose, fasting insulin, albumin, and HOMA index) were extracted when possible. For each outcome measure of interest, a meta-analysis was performed in order to determine the pooled effect of the intervention in terms of weighted mean differences between the post-intervention (or differences in means) values of the leucine and the respective control groups. Data analysis was performed using the Review Manager 5.2.4. software.

RESULTS

A total of 16 studies enrolling 999 subjects met the inclusion criteria. Compared with control groups, leucine supplementation significantly increased gain in body weight [mean differences 1.02 kg, 95%-CI (0.19, 1.85), p=0.02], lean body mass [mean differences 0.99 kg, 95%-CI (0.43, 1.55), p=0.0005], and body mass index [mean differences 0.33 kg/m2, 95%-CI (0.13, 0.53), p=0.001], when compared to the respective control groups. With respect to body weight and lean body mass, leucine supplementation turned out to be more effective in the subgroup of study participants with manifested sarcopenia. All other parameters under investigation were not affected by leucine supplementation in a fashion significantly different from controls.

CONCLUSIONS

It is concluded that leucine supplementation was found to exert beneficial effects on body weight, body mass index, and lean body mass in older persons in those subjects already prone to sarcopenia, but not muscle strength. However, due to the heterogeneity between the trials included in this systematic review, further studies adopting a homogenous design with respect to participant characteristics duration as well as the kind and amount of daily supplement in use are required.

New harmonic scalpel versus conventional hemostasis in right colon surgery: a prospective randomized controlled clinical trial

BACKGROUND

The Harmonic Scalpel (HS) is a device that uses vibrations to coagulate and cut tissues simultaneously. Its advantages are represented by minimal lateral thermal tissue damage, less smoke formation, no neuromuscular stimulation and no transmission of electricity to the patient.

METHODS

A total of 211 consecutive patients (113 men, 98 women; mean age 64 years) undergoing hemicolectomy for cancer of the right colon were divided into two groups, namely those in whom the operation was performed using a new HS handpiece (NHS; 108 patients) and those assigned to conventional hemostasis (CH; 103 patients). The two surgical groups were compared regarding patients' age and sex, tumor size, location, histotype and local invasiveness assessed by American Joint Cancer Committee stage, operative time, fluid content in the suction balloon (drainage volume) during the first 1-3 days after surgery, hospital stay and complications.

RESULTS

Ultrasonic energy delivered through an HS has been shown to be safe and to produce minimal damage to the surrounding tissues because of its minimal heat production. Electrical devices allow hemostatic control in vessels up to 3 mm in diameter, while HS can coagulate vessels up to 5 mm in diameter; thus, HS allows not only better control of bleeding but also of lymphorrhea. In fact, the amount of fluid collected in the drainage was significantly lower in the NHS group compared to the CH group. Protein depletion influences the patient's regenerative capacity and thus also the occurrence of complications and recovery time.

CONCLUSION

NHS is a useful device in colon surgery; it facilitates surgical maneuvers and reduces operative times and blood and lymphatic losses, allowing satisfactory maintenance of protein storage. This results in a lower incidence of complications and faster recovery by patients.

Treatment of metabolic syndrome by combination of physical activity and diet needs an optimal protein intake: a randomized controlled trial

BACKGROUND

The recommended dietary allowance (RDA) for protein intake has been set at 1.0-1.3 g/kg/day for senior. To date, no consensus exists on the lower threshold intake (LTI = RDA/1.3) for the protein intake (PI) needed in senior patients ongoing both combined caloric restriction and physical activity treatment for metabolic syndrome. Considering that age, caloric restriction and exercise are three increasing factors of protein need, this study was dedicated to determine the minimal PI in this situation, through the determination of albuminemia that is the blood marker of protein homeostasis.

METHODS

Twenty eight subjects (19 M, 9 F, 61.8 ± 6.5 years, BMI 33.4 ± 4.1 kg/m²) with metabolic syndrome completed a three-week residential programme (Day 0 to Day 21) controlled for nutrition (energy balance of -500 kcal/day) and physical activity (3.5 hours/day). Patients were randomly assigned in two groups: Normal-PI (NPI: 1.0 g/kg/day) and High-PI (HPI: 1.2 g/kg/day). Then, patients returned home and were followed for six months. Albuminemia was measured at D0, D21, D90 and D180.

RESULTS

At baseline, PI was spontaneously 1.0 g/kg/day for both groups. Albuminemia was 40.6 g/l for NPI and 40.8 g/l for HPI. A marginal protein under-nutrition appeared in NPI with a decreased albuminemia at D90 below 35 g/l (34.3 versus 41.5 g/l for HPI, p < 0.05), whereas albuminemia remained stable in HPI.

CONCLUSION

During the treatment based on restricted diet and exercise in senior people with metabolic syndrome, the lower threshold intake for protein must be set at 1.2 g/kg/day to maintain blood protein homeostasis.

Comparison of high-temperature conversion and equilibration methods for the determination of d31-palmitic acid oxidation in man using continuous-flow isotope ratio mass spectrometry

During nutritional interventions, the ingestion of d(31)-palmitic acid and H(2)(18)O allows the assessment of dietary fatty acid oxidation from cumulative (2)H recovery in urine and the estimation of the total body water pool (TBW) from (18)O dilution. Continuous-flow isotope ratio mass spectrometry (CF-IRMS) coupled to either equilibration or high-temperature conversion (HTC) techniques permits (2)H- and (18)O-enrichment measurements in biological fluids. Thus it was of great interest to compare these methods applied to the determination of dietary fatty acid oxidation. The linearity, accuracy and correlation between CF-equilibration and CF-HTC were first checked using (2)H- and (18)O-enriched water and urine samples. Urine samples from 14 subjects were then measured with both methods. The (2)H and (18)O raw data were normalised against calibration lines. The final aim was to study the impact of the normalised raw results on physiological data (i.e. TBW and d(31)-palmitate recovery). No significant difference was observed between the (18)O- and (2)H-enrichment measurements depending on the analytical method used. The TBW volumes calculated from the (18)O enrichments measured either with CF-equilibration or CF-HTC were not significantly different: respectively, 45.1 ± 1.0 L or 45.7 ± 1.0 L (mean ± sem, p = 0.09). The palmitic acid oxidation results obtained from the (2)H-enrichment measurements and the TBW from CF-equilibration vs. CF-HTC were not significantly different (p ≥ 0.26): with δ(2)H values of, respectively, 16.2 ± 1.6% vs. 16.2 ± 1.1% at 8 h, 18.7 ± 2.0% vs. 17.6 ± 1.3% at 12 h and 21.7 ± 1.9% vs. 21.5 ± 1.3% at 3 days post-dose (mean ± sem). Thus, even if CF-HTC was preferred because it was more practical to carry out, both methods allow the study of dietary lipid oxidation in man and generate similar results.