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Clinical Nutrition ESPEN Aug 2023The aim of the study was to map evidence on the association between phase angle (PhA) and body composition in populations healthy and clinical populations). A systematic... (Review)
Review
The aim of the study was to map evidence on the association between phase angle (PhA) and body composition in populations healthy and clinical populations). A systematic search for information regarding the topic was conducted in nine electronic databases (CINAHL, LILACS, PubMed, SciELO, Scopus, SPORTDiscus, Science Direct, MEDLINE and Web of Science) between October and November 2021. Studies with different designs, which allowed extracting information about the relationship between PhA and body composition (body cell mass [BCM], muscle tissue, bone mineral content, lean mass, total fat mass, visceral fat, and lean soft tissue mass [LSTM]) were included. Of the total of 11,913 initially identified studies, 59 were included after reading titles, abstracts, full texts and references. Most studies (40.67%; n = 24) presented data from Brazilian samples. With regard to the design of studies, 15 (25.42%) had longitudinal design. The age group of studies was wide, with studies involved 3-year-old children and 88-year-old adults. Body fat mass was evaluated by 31 studies (52.54%) in which 11 observed inverse relationships, nine studies showed direct relationships and 11 observed no relationship. Regarding lean mass, muscle mass, and fat-free mass components, most studies observed direct relationship with PhA (n = 37; 86.04%). It could be concluded that the phase angle was directly associated with lean mass and muscle mass in different age groups (children, adolescents, adults and older adults) and in people with different health diagnoses (HIV, cancer, hemodialysis, sarcopenia and without the diagnosis of diseases). Regarding body fat and the other investigated components, there is not enough evidence to establish the direction of associations.
Topics: Adolescent; Child, Preschool; Humans; Adipose Tissue; Body Composition; Bone Density; Muscle, Skeletal; Renal Dialysis; Adult; Aged, 80 and over
PubMed: 37344079
DOI: 10.1016/j.clnesp.2023.05.015 -
Journal of Cachexia, Sarcopenia and... Jun 2024Proliferating cancer cells shift their metabolism towards glycolysis, even in the presence of oxygen, to especially generate glycolytic intermediates as substrates for...
BACKGROUND
Proliferating cancer cells shift their metabolism towards glycolysis, even in the presence of oxygen, to especially generate glycolytic intermediates as substrates for anabolic reactions. We hypothesize that a similar metabolic remodelling occurs during skeletal muscle hypertrophy.
METHODS
We used mass spectrometry in hypertrophying C2C12 myotubes in vitro and plantaris mouse muscle in vivo and assessed metabolomic changes and the incorporation of the [U-C]glucose tracer. We performed enzyme inhibition of the key serine synthesis pathway enzyme phosphoglycerate dehydrogenase (Phgdh) for further mechanistic analysis and conducted a systematic review to align any changes in metabolomics during muscle growth with published findings. Finally, the UK Biobank was used to link the findings to population level.
RESULTS
The metabolomics analysis in myotubes revealed insulin-like growth factor-1 (IGF-1)-induced altered metabolite concentrations in anabolic pathways such as pentose phosphate (ribose-5-phosphate/ribulose-5-phosphate: +40%; P = 0.01) and serine synthesis pathway (serine: -36.8%; P = 0.009). Like the hypertrophy stimulation with IGF-1 in myotubes in vitro, the concentration of the dipeptide l-carnosine was decreased by 26.6% (P = 0.001) during skeletal muscle growth in vivo. However, phosphorylated sugar (glucose-6-phosphate, fructose-6-phosphate or glucose-1-phosphate) decreased by 32.2% (P = 0.004) in the overloaded muscle in vivo while increasing in the IGF-1-stimulated myotubes in vitro. The systematic review revealed that 10 metabolites linked to muscle hypertrophy were directly associated with glycolysis and its interconnected anabolic pathways. We demonstrated that labelled carbon from [U-C]glucose is increasingly incorporated by ~13% (P = 0.001) into the non-essential amino acids in hypertrophying myotubes, which is accompanied by an increased depletion of media serine (P = 0.006). The inhibition of Phgdh suppressed muscle protein synthesis in growing myotubes by 58.1% (P < 0.001), highlighting the importance of the serine synthesis pathway for maintaining muscle size. Utilizing data from the UK Biobank (n = 450 243), we then discerned genetic variations linked to the serine synthesis pathway (PHGDH and PSPH) and to its downstream enzyme (SHMT1), revealing their association with appendicular lean mass in humans (P < 5.0e-8).
CONCLUSIONS
Understanding the mechanisms that regulate skeletal muscle mass will help in developing effective treatments for muscle weakness. Our results provide evidence for the metabolic rewiring of glycolytic intermediates into anabolic pathways during muscle growth, such as in serine synthesis.
Topics: Glucose; Muscle, Skeletal; Animals; Mice; Humans; Hypertrophy; Muscle Fibers, Skeletal; Insulin-Like Growth Factor I; Metabolomics
PubMed: 38742477
DOI: 10.1002/jcsm.13468 -
The Cochrane Database of Systematic... Oct 2022There are several possible interventions for managing pressure ulcers (sometimes referred to as pressure injuries), ranging from pressure-relieving measures, such as... (Review)
Review
BACKGROUND
There are several possible interventions for managing pressure ulcers (sometimes referred to as pressure injuries), ranging from pressure-relieving measures, such as repositioning, to reconstructive surgery. The surgical approach is usually reserved for recalcitrant wounds (where the healing process has stalled, or the wound is not responding to treatment) or wounds with full-thickness skin loss and exposure of deeper structures such as muscle fascia or bone. Reconstructive surgery commonly involves wound debridement followed by filling the wound with new tissue. Whilst this is an accepted means of ulcer management, the benefits and harms of different surgical approaches, compared with each other or with non-surgical treatments, are unclear. This is an update of a Cochrane Review published in 2016.
OBJECTIVES
To assess the effects of different types of reconstructive surgery for treating pressure ulcers (category/stage II or above), compared with no surgery or alternative reconstructive surgical approaches, in any care setting.
SEARCH METHODS
We used standard, extensive Cochrane search methods. The latest search date was January 2022.
SELECTION CRITERIA
Published or unpublished randomised controlled trials (RCTs) that assessed reconstructive surgery in the treatment of pressure ulcers.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected the studies, extracted study data, assessed the risk of bias and undertook GRADE assessments. We would have involved a third review author in case of disagreement.
MAIN RESULTS
We identified one RCT conducted in a hospital setting in the USA. It enrolled 20 participants aged between 20 and 70 years with stage IV ischial or sacral pressure ulcers (involving full-thickness skin and tissue loss). The study compared two reconstructive techniques for stage IV pressure ulcers: conventional flap surgery and cone of pressure flap surgery, in which a large portion of the flap tip is de-epithelialised and deeply inset to obliterate dead space. There were no clear data for any of our outcomes, although we extracted some information on complete wound healing, wound dehiscence, pressure ulcer recurrence and wound infection. We graded the evidence for these outcomes as very low-certainty. The study provided no data for any other outcomes.
AUTHORS' CONCLUSIONS
Currently there is very little randomised evidence on the role of reconstructive surgery in pressure ulcer management, although it is considered a priority area. More rigorous and robust research is needed to explore this intervention.
Topics: Adult; Aged; Debridement; Humans; Middle Aged; Pressure Ulcer; Plastic Surgery Procedures; Wound Healing; Young Adult
PubMed: 36228111
DOI: 10.1002/14651858.CD012032.pub3 -
Cells Mar 2022microRNAs (miRNA, miRs) play crucial roles in cardiovascular disease regulating numerous processes, including inflammation, cell proliferation, angiogenesis, and cell... (Review)
Review
microRNAs (miRNA, miRs) play crucial roles in cardiovascular disease regulating numerous processes, including inflammation, cell proliferation, angiogenesis, and cell death. Herein, we present an updated and comprehensive overview of the functional involvement of miRs in the regulation of cardiomyocyte death, a central event in acute myocardial infarction, ischemia/reperfusion, and heart failure. Specifically, in this systematic review we are focusing on necrosis, apoptosis, and autophagy.
Topics: Apoptosis; Autophagy; Humans; MicroRNAs; Myocardial Infarction; Myocytes, Cardiac
PubMed: 35326433
DOI: 10.3390/cells11060983 -
Obesity Reviews : An Official Journal... Jul 2022Obesity derives from an extended period of positive energy imbalance due to a complex interplay of environmental and biological factors. Muscle fiber type and physiology... (Meta-Analysis)
Meta-Analysis Review
Obesity derives from an extended period of positive energy imbalance due to a complex interplay of environmental and biological factors. Muscle fiber type and physiology have been hypothesized to affect metabolism and energy expenditure and thus to affect an individual's propensity to gain weight. However, there have been conflicting reports regarding a relationship between muscle fiber type and obesity. Here, we systematically reviewed literature investigating this topic from PubMed, Web of Science, and EMBASE. Of these, 32 articles were included in our final review and analysis. Most studies (22/32) reported a significant relationship between muscle fiber-type proportion and a measure of obesity. Overall, there was a significant negative relationship between the proportion of type I fibers and body mass index (BMI) and a significant positive relationship between the proportion of type IIX fibers and BMI. Moreover, between-group comparisons indicated a greater prevalence of type IIX fibers and a lower prevalence of type I fibers in patients living with obesity relative to lean individuals. These significant relationships were confirmed in a meta-analysis of these data. The causal nature of these associations remains to be evaluated.
Topics: Body Mass Index; Humans; Muscle Fibers, Skeletal; Obesity
PubMed: 35293095
DOI: 10.1111/obr.13444 -
Journal of Biomechanics Dec 2021Understanding passive skeletal muscle mechanics is critical in defining structure-function relationships in skeletal muscle and ultimately understanding pathologically... (Review)
Review
Understanding passive skeletal muscle mechanics is critical in defining structure-function relationships in skeletal muscle and ultimately understanding pathologically impaired muscle. In this systematic review, we performed an exhaustive literature search using PRISMA guidelines to quantify passive muscle mechanical properties, summarized the methods used to create these data, and make recommendations to standardize future studies. We screened over 7500 papers and found 80 papers that met the inclusion criteria. These papers reported passive muscle mechanics from single muscle fiber to whole muscle across 16 species and 54 distinct muscles. We found a wide range of methodological differences in sample selection, preparation, testing, and analysis. The systematic review revealed that passive muscle mechanics is species and scale dependent-specifically within mammals, the passive mechanics increases non-linearly with scale. However, a detailed understanding of passive mechanics is still unclear because the varied methodologies impede comparisons across studies, scales, species, and muscles. Therefore, we recommend the following: smaller scales may be maintained within storage solution prior to testing, when samples are tested statically use 2-3 min of relaxation time, stress normalization at the whole muscle level be to physiologic cross-sectional area, strain normalization be to sarcomere length when possible, and an exponential equation be used to fit the data. Additional studies using these recommendations will allow exploration of the multiscale relationship of passive force within and across species to provide the fundamental knowledge needed to improve our understanding of passive muscle mechanics.
Topics: Animals; Muscle Fibers, Skeletal; Muscle, Skeletal; Sarcomeres
PubMed: 34736082
DOI: 10.1016/j.jbiomech.2021.110839 -
Nutrients Aug 2023This paper presents a systematic review of studies investigating the effects of fatty acid supplementation in potentially preventing and treating sarcopenia. PubMed,... (Review)
Review
This paper presents a systematic review of studies investigating the effects of fatty acid supplementation in potentially preventing and treating sarcopenia. PubMed, Embase, and Web of Science databases were searched using the keywords 'fatty acid' and 'sarcopenia'. Results: A total of 14 clinical and 11 pre-clinical (including cell and animal studies) studies were included. Of the 14 clinical studies, 12 used omega-3 polyunsaturated fatty acids (PUFAs) as supplements, 1 study used ALA and 1 study used CLA. Seven studies combined the use of fatty acid with resistant exercises. Fatty acids were found to have a positive effect in eight studies and they had no significant outcome in six studies. The seven studies that incorporated exercise found that fatty acids had a better impact on elderlies. Four animal studies used novel fatty acids including eicosapentaenoic acid, trans-fatty acid, and olive leaf extraction as interventions. Three animal and four cell experiment studies revealed the possible mechanisms of how fatty acids affect muscles by improving regenerative capacity, reducing oxidative stress, mitochondrial and peroxisomal dysfunctions, and attenuating cell death. Conclusion: Fatty acids have proven their value in improving sarcopenia in pre-clinical experiments. However, current clinical studies show controversial results for its role on muscle, and thus the mechanisms need to be studied further. In the future, more well-designed randomized controlled trials are required to assess the effectiveness of using fatty acids in humans.
Topics: Animals; Humans; Muscles; Cell Death; Databases, Factual; Dietary Supplements; Eicosapentaenoic Acid; Fatty Acids; Sarcopenia
PubMed: 37630803
DOI: 10.3390/nu15163613 -
Open Access Emergency Medicine : OAEM 2023Heatstroke (HS) is a severe form of heat-related illness (HRI) associated with high morbidity and mortality, representing a condition that includes long-term multiorgan...
INTRODUCTION
Heatstroke (HS) is a severe form of heat-related illness (HRI) associated with high morbidity and mortality, representing a condition that includes long-term multiorgan dysfunction and susceptibility to further heat illness.
METHODS
In a systematic review searching Medline PubMed from the studies conducted between 2009 and 2020, 16 papers were identified.
RESULTS
A hallmark symptom of heat stroke is CNS dysfunction (a hallmark sign of HS) which manifests as mental status changes, including agitation, delirium, epilepsy, or coma at the time of the collapse. Acute kidney injury (AKI), gut ischemia, blood clots in the stomach and small intestine, cytoplasmic protein clumps in the spleen, and injury of skeletal muscle (rhabdomyolysis) are all characteristics of peripheral tissue damage. Severe heat stroke tends to be complicated by rhabdomyolysis, especially in patients with exertional heat stroke. Rhabdomyolysis may lead to systemic effects, including the local occurrence of compartment syndrome, hyperkalemic cardiac arrest, and/or lethal disseminated intravascular coagulopathy. Untreated heat stroke might exacerbate psychosis, lactic acidosis, consumptive coagulopathy, hematuria, pulmonary edema, renal failure, and other metabolic abnormalities. Core body temperature and level of consciousness are the most significant indicators to diagnose the severity of heat stroke and prevent unfavorable consequences. Heatstroke is a life-threatening illness if not promptly recognized and effectively treated.
DISCUSSION
This review highlighted that core body temperature and white blood cell count are significant contributing factors affecting heat stroke outcomes. Other factors contributing to the poor outcome include old age, low GCS, and prolonged hospital stay. The prevalence of both classic and exertional heatstroke can be reduced by certain simple preventive measures, such as avoiding strenuous activity in hot environments and reducing exposure to heat stress.
PubMed: 37771523
DOI: 10.2147/OAEM.S419028 -
Nutrients Oct 2023Vitamin D deficiency, prevalent worldwide, is linked to muscle weakness, sarcopenia, and falls. Muscle regeneration is a vital process that allows for skeletal muscle... (Review)
Review
Vitamin D deficiency, prevalent worldwide, is linked to muscle weakness, sarcopenia, and falls. Muscle regeneration is a vital process that allows for skeletal muscle tissue maintenance and repair after injury. PubMed and Web of Science were used to search for studies published prior to May 2023. We assessed eligible studies that discussed the relationship between vitamin D, muscle regeneration in this review. Overall, the literature reports strong associations between vitamin D and skeletal myocyte size, and muscle regeneration. In vitro studies in skeletal muscle cells derived from mice and humans showed vitamin D played a role in regulating myoblast growth, size, and gene expression. Animal studies, primarily in mice, demonstrate vitamin D's positive effects on skeletal muscle function, such as improved grip strength and endurance. These studies encompass vitamin D diet research, genetically modified models, and disease-related mouse models. Relatively few studies looked at muscle function after injury, but these also support a role for vitamin D in muscle recovery. The human studies have also reported that vitamin D deficiency decreases muscle grip strength and gait speed, especially in the elderly population. Finally, human studies reported the benefits of vitamin D supplementation and achieving optimal serum vitamin D levels in muscle recovery after eccentric exercise and surgery. However, there were no benefits in rotator cuff injury studies, suggesting that repair mechanisms for muscle/ligament tears may be less reliant on vitamin D. In summary, vitamin D plays a crucial role in skeletal muscle function, structural integrity, and regeneration, potentially offering therapeutic benefits to patients with musculoskeletal diseases and in post-operative recovery.
Topics: Aged; Humans; Animals; Mice; Vitamin D; Muscle, Skeletal; Vitamins; Vitamin D Deficiency; Muscular Diseases; Models, Animal; Regeneration
PubMed: 37892452
DOI: 10.3390/nu15204377 -
Human Mutation Sep 2022The Dedicator of Cytokinesis (DOCK) family (DOCK1-11) of genes are essential mediators of cellular migration, growth, and fusion in a variety of cell types and tissues.... (Review)
Review
The Dedicator of Cytokinesis (DOCK) family (DOCK1-11) of genes are essential mediators of cellular migration, growth, and fusion in a variety of cell types and tissues. Recent advances in whole-genome sequencing of patients with undiagnosed genetic disorders have identified several rare pathogenic variants in DOCK genes. We conducted a systematic review and performed a patient database and literature search of reported DOCK pathogenic variants that have been identified in association with clinical pathologies such as global developmental delay, immune cell dysfunction, muscle hypotonia, and muscle ataxia among other categories. We then categorized these pathogenic DOCK variants and their associated clinical phenotypes under several unique categories: developmental, cardiovascular, metabolic, cognitive, or neuromuscular. Our systematic review of DOCK variants aims to identify and analyze potential DOCK-regulated networks associated with neuromuscular diseases and other disease pathologies, which may identify novel therapeutic strategies and targets. This systematic analysis and categorization of human-associated pathologies with DOCK pathogenic variants is the first report to the best of our knowledge for a unique class in this understudied gene family that has important implications in furthering personalized genomic medicine, clinical diagnoses, and improve targeted therapeutic outcomes across many clinical pathologies.
Topics: Ataxia; Genomics; Guanine Nucleotide Exchange Factors; Humans; Intellectual Disability; Multigene Family; Muscle Hypotonia; Transcription Factors
PubMed: 35544951
DOI: 10.1002/humu.24398