Search Results (350)

Background: The waist–calf circumference ratio (WCR) is an index that combines waist and calf circumference measurements, offering a potentially effective method for evaluating the imbalance between abdominal fat and leg muscle mass in older adults. Objective: To assess the association between WCR and indicators of body composition, muscle strength, and physical performance in community-dwelling older women. Methods: This was a cross-sectional study involving 133 older women (≥65 years) from an urban-marginal community in Guayaquil, Ecuador. The WCR was categorized into quartiles (Q1: 2.07–2.57; Q2: 2.58–2.75; Q3: 2.76–3.05; Q4: 3.06–4.76). Body indicators included fat-free mass (FFM), skeletal muscle mass (SMM), appendicular muscle mass (ASM), appendicular muscle mass index (ASMI), visceral fat (VF), fat mass (FM), and fat mass index (FMI). Handgrip strength (HGS) and the Short Physical Performance Battery test (SPPB) score were used to assess muscle strength and function, respectively. Results: The median age of the participants was 75 [IQR: 65–82] years. The mean WCR was 2.92 ± 0.93. Statistically significant associations were found between WCR and VF (p < 0.001), WCR and SMM (p = 0.039), and WCR and ASM (p = 0.016). Regarding muscle function, WCR was associated with HGS (p = 0.025) and SPPB score (p = 0.029). Conclusions: A significant association was observed between WCR and body composition, and muscle strength and function in older women. Full article

Background and Objectives: This study aims to investigate the relationship between isokinetic knee strength and competition performance in elite male ski mountaineering sprint athletes and to identify strength parameters that predict performance and contribute to injury prevention. Materials and Methods: Thirteen male athletes participating in the Ski Mountaineering Turkey Cup final stage were included. Isokinetic knee flexion (FLX) and extension (EXT) strength of dominant (DM) and non-dominant (NDM) legs were measured at angular velocities of 60°/s and 180°/s using the DIERS-Myolin Isometric Muscle Strength Analysis System. Competition performance was evaluated using the ISMF scoring system. Data were analyzed using SPSS 26.0 with Pearson correlation and multiple regression analyses after normality, linearity, and homoscedasticity checks. Results: Strong positive correlations were found between hamstring strength at high angular velocities (180°/s) and performance (DM FLX: r = 0.809; NDM FLX: r = 0.880). Extension strength showed moderate correlations at low velocities (60°/s) (DM EXT: r = 0.677; NDM EXT: r = 0.699). Regression analysis revealed that DM FLX at 180°/s and DM EXT at 60°/s explained 49% of performance variance (Adj. R² = 0.498). For NDM legs, only 180°/s FLX was a significant predictor (β = 1.468). Conclusions: High-velocity hamstring strength plays a critical role in ski mountaineering sprint performance, particularly during sudden directional changes and dynamic balance. Quadriceps strength at low velocities contributes to prolonged climbing phases. Moreover, identifying and addressing bilateral strength asymmetries may support injury prevention strategies in elite ski mountaineering athletes. These findings provide scientific support for designing training programs targeting explosive hamstring strength, bilateral symmetry, and injury risk reduction, essential for optimizing performance in the 2026 Winter Olympics sprint discipline. Full article

Calcium (Ca²⁺) signaling is a fundamental regulatory mechanism controlling essential processes in the endothelium, vascular smooth muscle cells (VSMCs), and the extracellular matrix (ECM), including maintaining the endothelial barrier, modulation of vascular tone, and vascular remodeling. Cytosolic free Ca²⁺ concentration is tightly regulated by a balance between Ca²⁺ mobilization mechanisms, including Ca²⁺ release from the intracellular stores in the sarcoplasmic/endoplasmic reticulum and Ca²⁺ entry via voltage-dependent, transient-receptor potential, and store-operated Ca²⁺ channels, and Ca²⁺ elimination pathways including Ca²⁺ extrusion by the plasma membrane Ca²⁺-ATPase and Na⁺/Ca²⁺ exchanger and Ca²⁺ re-uptake by the sarco(endo)plasmic reticulum Ca²⁺-ATPase and the mitochondria. Some cell membranes/organelles are multifunctional and have both Ca²⁺ mobilization and Ca²⁺ removal pathways. Also, the individual Ca²⁺ handling pathways could be integrated to function in a regenerative, capacitative, cooperative, bidirectional, or reciprocal feed-forward or feed-back manner. Disruption of these pathways causes dysregulation of the Ca²⁺ signaling dynamics and leads to pathological cardiovascular conditions such as hypertension, coronary artery disease, atherosclerosis, and vascular calcification. In the endothelium, dysregulated Ca²⁺ signaling impairs nitric oxide production, reduces vasodilatory capacity, and increases vascular permeability. In VSMCs, Ca²⁺-dependent phosphorylation of the myosin light chain and Ca²⁺ sensitization by protein kinase-C (PKC) and Rho-kinase (ROCK) increase vascular tone and could lead to increased blood pressure and hypertension. Ca²⁺ activation of matrix metalloproteinases causes collagen/elastin imbalance and promotes vascular remodeling. Ca²⁺-dependent immune cell activation, leukocyte infiltration, and cholesterol accumulation by macrophages promote foam cell formation and atherosclerotic plaque progression. Chronic increases in VSMCs Ca²⁺ promote phenotypic switching to mesenchymal cells and osteogenic transformation and thereby accelerate vascular calcification and plaque instability. Emerging therapeutic strategies targeting these Ca²⁺-dependent mechanisms, including Ca²⁺ channel blockers and PKC and ROCK inhibitors, hold promise for restoring Ca²⁺ homeostasis and mitigating vascular disease progression. Full article

Background/Objectives: This study aims to assess dietary quality among Chinese pregnant women across three gestational trimesters using different assessment indices while investigating the relationship between dietary patterns and longitudinal alterations in maternal body composition parameters and bone mineral density (BMD) during pregnancy. Methods: A total of 556 healthy pregnant women were recruited. Dietary intake was assessed utilizing a semi-quantitative food frequency questionnaire (FFQ). Diet quality was evaluated through three indices: the Dietary Balance Index for Pregnant Women (DBI-P), the Dietary Inflammatory Index (DII), and the Eastern Health Diet Index (EHDI). Multiple linear regression models and mediation analyses were constructed to elucidate the relationships between dietary indices, body composition parameters, and BMD. Results: In the first trimester, excessive dietary intake was associated with increased maternal fat mass but reduced BMD, while insufficient intake correlated with declines in muscle mass, water compartments, and inorganic salt levels. Pro-inflammatory diets further exacerbated reductions in non-fat body composition, including protein and muscle mass. By the second trimester, low-quality diets continued to negatively affect muscle mass and water balance, whereas no significant dietary effects on body composition or BMD were observed in the third trimester. Mediation analyses revealed that body composition partially mediated the relationship between dietary imbalance and reduced BMD. Conclusions: Unbalanced, pro-inflammatory, and low-quality diets during early-to-mid pregnancy contribute to adverse changes in maternal body composition and bone health, especially in the first and second trimesters, with the DBI-P index demonstrating superior applicability for assessing dietary impacts in Chinese pregnant women. Full article

The fine regulation of antioxidant systems and intracellular production of reactive oxygen species (ROS) is responsible for cellular redox balance. The main organelles responsible for ROS production are mitochondria, and they complete this process through the electron transport chain. These potentially harmful molecules are buffered by enzymatic and non-enzymatic antioxidant systems. Oxidative stress is determined by an imbalance between the production and clearance of ROS in favor of the accumulation of these detrimental species, which generate cellular damage by interacting with macromolecules. In neurodegenerative diseases, oxidative stress has been demonstrated to be a crucial component, both causal and consequential to the disease itself. On the other hand, neurodegeneration disrupts neuromuscular junctions, leading to reduced muscle use and subsequent atrophy. Additionally, systemic inflammation and metabolic dysfunction associated with neurodegenerative diseases exacerbate muscle degeneration. Thus, sarcopenia and atrophy are common consequences of neurodegeneration and play a significant role in these disorders. Regarding this, ROS have been defined as promoting sarcopenia, stimulating the expression of genes typical of this condition. Overall, this review aims to contribute to filling the gap in the literature regarding the consequences at the muscular level of the relationship between oxidative stress and neurodegenerative diseases. Full article

Cancer cachexia is a multi-organ and multifactorial syndrome characterized by muscle wasting (with or without adipose tissue loss) and systemic inflammation in patients with advanced malignancies. Gut microbiota dysbiosis, particularly the depletion of short-chain fatty acid (SCFA)-producing bacteria, may contribute to the progression of cancer cachexia. Studies in both murine models and humans consistently associate cachexia with a decline in SCFA-producing gut microbiota commensals and an overgrowth of pro-inflammatory pathobionts. These microbial imbalances may lead to reduced levels of SCFAs and branched-chain amino acids (BCAAs) and alter the normal bile acid profile. BCAAs and the maintenance of a normal bile acid profile are associated with muscle synthesis and decreased breakdown. While SCFAs (acetate, propionate, and butyrate), contribute to intestinal barrier integrity and immune regulation. SCFA depletion may increase gut permeability, allowing bacterial endotoxins, such as lipopolysaccharide (LPS), to enter the bloodstream. This may lead to chronic inflammation, muscle catabolism, and impairment of anabolic pathways. Interventions targeting gut microbiota in preclinical models have mitigated inflammation and muscle loss. While clinical data are limited, it suggests an improvement in immune functions and better tolerance to anticancer therapies. Current evidence is predominantly derived from cross-sectional studies suggesting associations without causality. Thus, future longitudinal studies are needed to identify biomarkers and optimize personalized therapy. Full article

Background: Temporomandibular disorders (TMDs) represent an umbrella term encompassing various musculoskeletal dysfunctions, including those affecting the masticatory muscles. This study aimed to compare the salivary levels of non-enzymatic antioxidants and redox balance between patients with temporomandibular myofascial pain with referral and matched healthy controls. Methods: The sample consisted of 44 individuals diagnosed with temporomandibular myofascial pain with referral and a matched control group. The procedure included a clinical examination based on the Diagnostic Criteria for Temporomandibular Disorders and saliva collection. Biochemical analysis included the assessment of reduced glutathione (GSH) levels, total antioxidant status (TAC), total oxidant status (TOS), and the oxidative stress index (OSI). Results: Patients with temporomandibular myofascial pain with referral exhibited higher levels of total oxidant status and glutathione. The mean value of total antioxidant capacity was lower, although the median was higher compared to the control group. No statistically significant differences were observed in the oxidative stress index between the two groups. Conclusions: Patients with temporomandibular myofascial pain with referral exhibit oxidative imbalance, reflected by increased salivary levels of non-enzymatic antioxidants, elevated total oxidant status, and significant differences in antioxidant capacity compared to healthy controls. Individually tailored physical activity, proper nutrition, and targeted supplementation may be necessary to maintain oxidative-antioxidant balance in this patient population. Full article

In the aging population, imbalance leading to falls is of critical concern; thus, it is imperative to determine and quantify neuromuscular changes because of rehabilitative balance training. (1) Background: Previous studies that have examined changes in balance due to rehabilitative training placed a focus on clinical measures (i.e., behavioral, kinetic, and kinematic outputs); however, irregularities due to abnormalities of underlying neural origin were unrevealed by the aforementioned measures. (2) Methods: Examining muscle activity was used to determine strategies pre- and post-six weeks of balance training in twenty-three healthy older adults (69.5 ± 5.7 years old) and five survivors of stroke (66.4 ± 9.48 years old). Surface electromyographic (sEMG) signals were recorded from eight of the lower limb muscles while participants performed forward walking (FW), forward tandem walking (FT-W), backward walking (BW), and backward tandem walking (BT-W) tasks. The sEMG data were then conditioned and muscle synergies were extracted using non-negative matrix factorization (NNMF). (3) Results: It was observed that muscle synergies and activation patterns changed for pre- versus post-balance training in older adults (i.e., healthy individuals and those who had suffered from stroke). (4) Conclusions: From our findings, it was indicative that muscle activation and muscle synergies could be used to quantify and inform rehabilitative balance training in older adults. Full article

Background: Osteosarcopenic obesity (OSO) syndrome, also defined as osteosarcopenic adiposity (OSA), is characterized by the concurrent loss of bone and muscle mass, accompanied by excess fat, leading to reduced functionality and metabolic imbalances. Recent studies have highlighted the role of microRNAs (miRNAs) in the pathophysiology of OSO/OSA, showing differential expression in individuals with osteosarcopenia and obesity. However, a thorough investigation in this area has been limited. Methods: A comprehensive search of international bibliographic databases, including Embase, PubMed and Scopus, was conducted. Results: From an initial search yielding 1311 records, 19 studies met the eligibility criteria for final evaluation. These findings highlight how physical exercise and nutritional factors can influence miRNA expression, emphasizing their role in promoting better health outcomes in aging populations. Furthermore, the critical role of miRNAs as indicators of muscle atrophy and the biological processes associated with aging and sarcopenia have been documented in various animal studies. Conclusions: Despite the limitations of this review, the findings indicate that miRNAs could serve as promising biomarkers and therapeutic targets for managing OSO/OSA. These results suggest that targeted interventions, such as resistance training and lifelong exercise, may effectively influence miRNA expression, potentially alleviating the impacts of OSO/OSA. Full article

Spasticity is a common complication after spinal cord injury (SCI) that significantly diminishes quality of life and complicates daily management. As a hallmark of upper motor neuron lesions, spasticity emerges through a complex post-injury process involving the resolution of spinal shock, an imbalance between excitatory and inhibitory signaling, and maladaptive neuronal plasticity, leading to hyperreflexia and chronic spasticity. Severe spasticity frequently results in pain, sleep disturbances, and marked functional impairments. This review systematically integrates motor neuron alterations with corresponding muscle manifestations, providing a comprehensive analysis of the brain–spinal cord–muscle pathway in spasticity pathogenesis. Through an in-depth analysis of the pathological and physiological changes in motor neurons post-SCI, this review offers a novel perspective that unveils the intrinsic mechanisms underlying spasticity formation, thereby establishing a robust theoretical foundation for developing targeted therapeutic strategies. Full article

Stomatognathic dysfunctions, particularly bruxism, orofacial pain, and temporomandibular joint (TMJ) disorders, are frequently associated with anxiety and depression. However, the reverse hypothesis that these dysfunctions may act as peripheral stressors contributing to neuropsychological imbalance by activating the hypothalamic–pituitary–adrenal (HPA) axis remains underexplored. Objective: To assess the relationship between the severity of stomatognathic symptoms and both physiological and psychological stress markers to determine whether such dysfunctions may influence or exacerbate anxiety and depressive disorders. Methods: A cross-sectional observational study was conducted on 120 adult patients. Clinical assessment was included evaluation of TMJ function, bruxism, and orofacial pain. Psychological screening was performed using validated questionnaires (GAD-7 for anxiety and PHQ-9 for depression). Electromyographic (EMG) analysis of the masseter and temporalis muscles was conducted, along with the quantification of salivary cortisol using an enzyme-linked immunosorbent assay (ELISA). Multiple regression models were applied to identify statistically significant correlations (p < 0.05). Results: A positive correlation was found between the severity of stomatognathic dysfunction and scores on anxiety and depression measures, along with elevated salivary cortisol levels and increased masticatory muscle activity. Conclusions: These findings suggest a bidirectional relationship between stomatognathic dysfunctions and neuropsychological status, underscoring the potential value of integrated therapeutic approaches that combine dental care with psychological support. Full article

Sarcopenic obesity (SO), characterized by an excess of fat and a decrease in muscle strength or mass, is a global public health concern and is linked to metabolic conditions such as metabolic syndrome (MetS). Different mechanisms contribute to SO, such as inflammation, fatty acid infiltration, and insulin resistance (IR). Recently, myostatin (MYOST), an inhibitory factor for skeletal muscle tissue, was proposed as an aimed compound for the treatment of conditions of muscular metabolic imbalance mass and MetS. On the other hand, a therapy with natural compounds such as resveratrol (R) and quercetin (Q) is effective for the treatment of MetS, but its effect on the MYOST pathway has been poorly explored. The control group received water, and the MetS group received 30% commercial sugar in the drinking water for 6 months. Polyphenol mix (R at a dose of 50 mg/kg/day and Q at 0.95 mg/kg/day) was administered for 1 month. MetS rats present SO linked to an increase in the expression of MYOST/ActRIIA and ActRIIB (p < 0.0001). R+Q treatment prevented SO by lowering the expression of MYOST and its receptors and increased the expression of Smad 7 in MetS rats (p < 0.0001). Moreover, the polyphenol treatment reverted IR by increasing Akt phosphorylation, leading to an increase in muscle mass. It decreased lipid stores, restored glycogen accumulation, and increased myosin expression (p < 0.0001). The results of this work indicate that R+Q supplementation could be a promising therapeutic agent to prevent SO and sarcopenia derived from other metabolic alterations. Full article

Background/Objectives: Shoulder injuries are common in overhead sports like tennis due to repetitive unilateral movements that can lead to muscle imbalances. This study aimed to compare muscle recruitment and asymmetry during bilateral shoulder injury prevention exercises (performed with both arms simultaneously) in tennis players versus non-tennis athletes. Methods: Thirty-nine athletes (sixteen tennis players, twenty-three non-tennis athletes) performed two bilateral scapular retraction exercises at 45° and 90° shoulder abduction. Surface electromyography (sEMG) recorded the activation of the middle and lower trapezius. Root Mean Square (RMS), peak RMS and muscle symmetry indices were analyzed. Results: Tennis players showed significantly lower trapezius activation, especially during prone retraction at 90°. Muscle symmetry was slightly higher in tennis players at 90°, but asymmetry increased at 45°, suggesting angle-specific adaptations. Conclusions: Repetitive asymmetric loading in tennis may reduce the activation of scapular stabilizers and contribute to muscular imbalances. Including targeted bilateral exercises in training may help improve scapular muscle function and reduce injury risk in overhead athletes. Full article

Aquaculture has been rapidly growing during the past decade to accommodate the increasing need for seafood as a vital source of nutrients for human beings. The nutritional benefits of incorporating fish into one’s diet are paramount in promoting overall health, bolstering immunity and warding off diseases. Nonetheless, farm-raised aquatic species are frequently subjected to elevated contamination levels due to pesticides, antibiotics, and heavy metals in the marine environment. Pesticides affect fish differently based on species, class, dosage, and exposure duration. They can induce histological damage or neurobehavioral changes by inhibiting acetylcholinesterase production. This can promote liver dysfunction, metabolism deregulation, oxidative stress, and hematological imbalances, impair immune responses, and adversely affect fish reproduction. Furthermore, pesticides negatively affect the nutritional composition of fish by reducing the total protein levels in muscle, liver, gills, and kidney tissues. They disrupt lipid metabolism, resulting in lipid accumulation in the liver and a decrease in polyunsaturated fatty acids. Additionally, pesticides interfere with metabolism by altering carbohydrate levels in the gills, muscles, and kidneys while decreasing glycogen storage in the liver. Pesticide exposure has been linked to severe health impacts in humans, such as non-communicable diseases, reproductive issues, cognitive dysfunction, and cancer. The current review comprehensively emphasizes the harmful effects of pesticides on fish and human health, urging the establishment of environmental monitoring programs and biomonitoring studies. It accentuates the need for risk assessment models to evaluate pesticide impacts on marine ecosystems and advocates for stricter safety standards and lower pesticide residue limits in aquaculture products. Full article

This review examines the impact of heat stress (HS) on carcass traits, meat quality, and nutritional composition in monogastric animals, specifically poultry and swine, and evaluates targeted nutritional strategies for mitigation. With rising global temperatures and intensified heat waves, HS has emerged as a key threat to animal welfare, production efficiency, and meat quality. Physiological disturbances induced by HS, including oxidative stress, protein denaturation, mitochondrial dysfunction, and hormonal imbalances, contribute to reduced carcass yield, muscle degradation, and inferior sensory attributes such as tenderness, juiciness, and flavour. HS also diminishes the nutritional value of meat by depleting essential amino acids, polyunsaturated fatty acids, and antioxidant micronutrients. This review highlights nutritional interventions, including antioxidant supplementation (e.g., vitamin E, selenium, polyphenols), osmolytes (e.g., betaine, taurine), probiotics, prebiotics, and optimised energy-to-protein ratios, as promising tools to enhance thermotolerance and meat quality. Emerging feed additives such as phytochemicals also show potential for protecting muscle integrity and improving oxidative stability. Given species-specific responses and production system variability, integrating these dietary approaches with stage-specific management is essential for resilience under climate stress. Future research should focus on the precision nutrition, biomarker identification, and validation of synergistic nutritional strategies that safeguard performance and meat quality in monogastric production systems. Full article