Search Results (67)

Declines of skeletal muscle mass and functions are implicated in the progression of various clinical conditions such as cancers, obesity, insulin resistance, diabetes, and osteoporosis. While no effective and safe drugs against muscle wasting, such as sarcopenia and disease-associated cachexia, have been discovered, it is well documented that dietary essential amino acids (EAAs) or high-quality protein work synergistically to enhance the anabolic effect of resistance exercise training (RT), leading to gains in muscle mass, strength, and muscle quality. Dietary EAAs serve as precursors and signaling molecules for the synthesis of new muscle proteins (both contractile and mitochondrial) and stimulate neuromuscular junction remodeling. Furthermore, EAAs consumed in the post-absorptive state improve endurance capacity via stimulation of mitochondrial biogenesis (independent of PGC1-α) and mitochondrial dynamics (mitochondrial protein synthesis and fission). Here, we discuss (1) traditional molecular mechanisms regulating the muscle proteome through constant turnover (synthesis and breakdown), (2) novel mechanisms by which dietary supplementation of EAAs during RT simultaneously improves muscle strength and endurance, (3) stable isotope tracer methodologies that enable understanding of the dynamic muscle proteome and accurate assessment of functional muscle mass, and finally, (4) clinical implications of combined EAA and RT interventions in the context of muscle and metabolic dysfunction, including sarcopenia, cachexia, obesity, and chronic disease. Collectively, current evidence underscores the potential of balanced EAAs, particularly when combined with resistance training, as a safe, effective, and translationally relevant nutritional strategy to preserve and enhance muscle and metabolic health across healthy and clinical populations. Full article

Sarcopenia is increasingly recognized as a key extracardiac manifestation of heart failure (HF), contributing to functional impairment, reduced quality of life, and adverse clinical outcomes. Characterized by progressive loss of skeletal muscle mass, strength, and physical performance, it affects more than half of hospitalized HF patients. It is independently associated with increased mortality and reduced exercise capacity. The pathophysiology of sarcopenia in HF is multifactorial and closely linked to metabolic and nutritional disturbances. Chronic inflammation, neurohormonal activation, oxidative stress, endothelial dysfunction, and anabolic resistance contribute to muscle catabolism and impaired protein synthesis. These alterations are further exacerbated by inadequate dietary protein intake and micronutrient deficiencies, promoting progressive muscle wasting and functional decline. Sarcopenia may also represent an early and potentially modifiable stage in the continuum toward cardiac cachexia. This narrative review provides a comprehensive synthesis of current evidence on the epidemiology, pathophysiological mechanisms, and management of sarcopenia in HF, with particular emphasis on nutritional and metabolic determinants. Emerging data support a multimodal therapeutic approach integrating exercise training with targeted nutritional strategies, including adequate protein intake, essential amino acid supplementation, and correction of micronutrient deficiencies. However, evidence from large, well-designed trials remains limited. In summary, improved recognition and integrated management of sarcopenia in HF are essential. Future research should focus on the development of effective, nutrition-centered therapeutic strategies. Full article

Chronic obstructive pulmonary disease, interstitial lung disease, and post-lung trans-plantation are often accompanied by skeletal muscle dysfunction that worsens the quality of life. Such physiological changes are driven by physical inactivity, systemic inflammation, oxidative stress, anabolic and hormonal resistance, and medication effects. Structural changes include impaired capillarization, fiber-type shifts (slow-to-fast in limb muscle and fast-to-slow in respiratory muscles), mitochondrial dysfunction, reduced oxidative capacity, and early lactate accumulation. Electromyography and dynamometry, both isokinetic and isometric, quantify neuromuscular drive through measuring strength, power, and endurance and are associated with functional outcomes (6-min walk, sit-to-stand, stair climbing tests). Pulmonary rehabilitation (PR) improves neuromuscular efficiency, dyspnea, exercise tolerance, and quality of life by combining resistance, endurance, and eccentric training. The effects of PR generally plateau at three months, emphasizing the need for maintenance and the personalization of rehabilitation plans. While nutritional optimization is important, supplements have shown little benefit. Future priorities include defining EMG/dynamometry thresholds to allow standardized routine testing for comparable benchmarks and more precise PR protocols. Future research targeting mitochondrial remodeling, inflammatory signaling, and anabolic resistance offer potential pathways for preventing and reversing muscle wasting. Full article

Sarcopenia, characterized by the progressive loss of skeletal muscle mass, strength, and function, represents a major public health challenge in aging populations. This condition affects approximately 10–16% of community-dwelling older adults and is associated with increased risks of falls, frailty, functional decline, and mortality. The pathogenesis of sarcopenia involves chronic low-grade inflammation (inflammaging), oxidative stress, mitochondrial dysfunction, and anabolic resistance. Omega-3 polyunsaturated fatty acids (PUFAs), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have emerged as promising nutritional interventions due to their anti-inflammatory properties and potential anabolic effects on skeletal muscle. This comprehensive review evaluates the current evidence on omega-3 PUFA supplementation for the attenuation and management of sarcopenia. Mechanistically, omega-3 PUFAs appear to enhance muscle protein synthesis through activation of the mTOR-p70S6K signaling pathway, reduce inflammation via specialized pro-resolving mediators (SPMs), improve mitochondrial bioenergetics, and attenuate muscle disuse atrophy. Clinical trials demonstrate that omega-3 supplementation, particularly at doses exceeding 2 g/day of combined EPA and DHA, can increase thigh muscle volume, handgrip strength, and one-repetition maximum strength in older adults. When combined with resistance exercise training, the benefits appear more pronounced, especially in women. However, heterogeneity in study designs, intervention durations, dosages, and outcome measures has produced some conflicting results. Large-scale trials, such as the MAPT study, have shown null findings for long-term supplementation alone, suggesting that omega-3s may be most effective as part of multimodal interventions. The evidence also supports benefits in clinical populations at risk for muscle wasting, including cancer patients experiencing cachexia and individuals with neuromuscular disorders. Future research should focus on identifying optimal dosing strategies, understanding sex-specific responses, and elucidating the mechanisms underlying the synergistic effects of omega-3s with exercise. Overall, omega-3 PUFA supplementation represents a safe, accessible, and potentially effective nutritional strategy for attenuating muscle decline in aging and clinical populations, though its benefits appear most pronounced when combined with resistance exercise as part of a multimodal approach. Full article

Pulmonary arterial hypertension (PAH) has traditionally been viewed as a vasculocentric disorder, with current therapies failing to reverse vascular remodeling or address pervasive systemic metabolic abnormalities. This review synthesizes emerging evidence to propose a paradigm shift, conceptualizing PAH as a systemic metabolic–immunological network disease. It examines how metabolic dysfunction in peripheral organs (adipose tissue, liver, skeletal muscle) and immunometabolic reprogramming of immune cells (e.g., macrophages, lymphocytes) synergistically drive pathology. These components engage in dynamic crosstalk via circulating mediators (metabolites, adipokines, cytokines), creating a self-amplifying loop that fuel pulmonary vascular inflammation and remodeling. Key mechanisms explored include adipose tissue endocrine dysfunction (contributing to the obesity paradox), hepatic insulin resistance and bile acid signaling, skeletal muscle energy crisis and wasting, and the pivotal roles of macrophage glycolytic polarization and T-cell subset imbalance. Insulin resistance/hyperglycemia emerges as a central hub linking metabolic and immune dysregulation. The review concludes that future therapeutic strategies must move beyond vasodilation to target this systemic network, discussing the potential of repurposed metabolic agents, direct immunometabolic modulators, and integrated lifestyle interventions to disrupt disease progression. Full article

Liver cirrhosis represents the end stage of chronic liver disease arising from diverse etiologies and is characterized by persistent hepatic injury, architectural distortion, extensive fibrosis, and nodular regeneration. While decompensated cirrhosis is commonly associated with overt, life-threatening complications such as hepatic encephalopathy, hepatorenal syndrome and gastrointestinal bleeding, less apparent manifestations—including sarcopenia and metabolic disturbances—have emerged as major determinants of prognosis. Sarcopenia, defined by the progressive loss of skeletal muscle mass and function, is highly prevalent in cirrhotic patients and is closely linked to frailty, increased morbidity, mortality, and adverse liver transplantation outcomes. Increasing data support the role of gastrointestinal dysfunction in the pathogenesis of sarcopenia in liver cirrhosis. In chronic liver disease, intestinal dysfunction is exacerbated by portal hypertension, which promotes increased intestinal permeability and bacterial translocation. Furthermore, gut dysbiosis, a key feature of advanced liver disease, contributes to impaired digestion, malabsorption of macro- and micronutrients, increased intestinal permeability, malnutrition and systemic inflammation. These alterations promote negative energy balance, reduce muscle protein synthesis and enhance muscle catabolism, thereby accelerating muscle wasting. Despite increasing recognition of the individual roles of gut dysbiosis, malabsorption, and sarcopenia in cirrhosis, their complex interrelationship has not been comprehensively addressed. This narrative review synthesizes current evidence on the interplay between gut dysbiosis, malabsorption and sarcopenia in patients with liver cirrhosis. We discuss underlying pathophysiological mechanisms, clinical implications and potential therapeutic strategies, while highlighting existing knowledge gaps and future research directions. Improved understanding of the gut-liver-muscle axis may offer novel opportunities for early intervention and optimization of outcomes in this high-risk patient population. Full article

Cancer cachexia is a multifactorial metabolic syndrome characterized by progressive skeletal muscle wasting, chronic systemic inflammation, and profound metabolic imbalance. Sustained activation of the nuclear factor κB (NF-κB) signaling pathway lies at the core of its pathogenesis, driving muscle proteolysis, impairing regenerative capacity, disrupting adipose tissue homeostasis, and promoting insulin resistance and anorexia. By transcriptionally regulating catabolic and pro-inflammatory gene programs across skeletal muscle, adipose tissue, the liver, and the central nervous system, NF-κB establishes a self-amplifying inflammatory–metabolic loop that perpetuates tissue wasting and systemic dysfunction. Accumulating preclinical and clinical evidence identifies NF-κB as a viable therapeutic target in cancer cachexia. Pharmacologic inhibitors (e.g., SR12343, DHMEQ), anti-inflammatory strategies (e.g., nonsteroidal anti-inflammatory drugs and IL-6 receptor–targeting antibodies), and nutritional interventions (e.g., omega-3 fatty acids) have shown efficacy in attenuating cachexia-associated inflammation, metabolic dysregulation, and tissue loss. Notably, emerging multimodal approaches integrating NF-κB modulation with metabolic support, chemotherapy, and behavioral interventions demonstrate synergistic benefits. This review integrates current mechanistic insights and therapeutic advances, highlighting NF-κB as a central pathogenic axis and a compelling target for translational intervention in cancer cachexia. Full article

Background: Although Duchenne muscular dystrophy (DMD) is primarily characterized as a skeletal muscle-wasting disorder, the resulting pathophysiological changes extend to multiple non-muscle tissues and organ systems. Among these, renal and urinary tract dysfunctions have been reported, albeit in relatively few studies, as potential complications in DMD patients, sometimes occurring from an early age. Importantly, as life expectancy improves, the incidence of renal impairment is also expected to increase. This narrative review summarizes the available evidence on kidney involvement in DMD and discusses the associated biomarkers of renal dysfunction within the context of multisystem disease progression. Methods: The review draws on data from both human and animal studies and analyzes published evidence to explore kidney involvement in DMD, with a focus on clinical manifestations, biomarkers of renal dysfunction, and potential pathogenic mechanisms. Results: Available data indicate a close association between cardiac and renal dysfunction, particularly in patients with advanced-stage DMD. The review explores potential underlying mechanisms of renal impairment, including intrinsic dystrophin deficiency in the kidney, secondary effects of cardiovascular complications, and the nephrotoxic impact of drug therapies, highlighting renal function as an active determinant of clinical risk. Conclusions: While cardiac function monitoring is already a cornerstone of multidisciplinary care for this multisystem disease, systematic assessment of renal function should also be implemented, with implications for clinical management and drug safety. Moreover, the risk of drug-induced nephrotoxicity warrants attention in both clinical management and the development of novel therapeutic strategies for DMD. Full article

Duchenne muscular dystrophy (DMD) is a rare neuromuscular disorder that is characterized by skeletal muscle wasting, loss of ambulation, and respiratory failure. In addition to these obvious external signs of disease, heart disease, the leading cause of death in DMD patients, is also progressing. Dystrophic cardiomyopathy is largely clinically silent with cardiac dysfunction masked by concurrent loss of skeletal muscle function. In older DMD patients the prevalence of heart disease is very high, offering the unique potential to predict impending heart disease from a much earlier genetic diagnosis. Randomized clinical trial data and subsequent retrospective studies in DMD demonstrate that early initiation of cardiac directed therapy results in a significant delay in the onset of cardiac dysfunction and prolonged survival. Clinical guidelines reflect this, recommending the initiation of cardiac therapy at an age of 10 years old, even in the absence of documented contractile dysfunction. Despite this data, a recent examination of registry data reveals that most DMD patients are not receiving the treatments recommended by these guidelines. While there is great excitement regarding newly developed therapies for DMD, there are so many signs that deploying the safe and effective therapies we already have can improve clinical outcomes. This review will highlight the basic science behind and clinical importance of using early cardiac directed therapy to extend the duration and quality of life of DMD patients and will offer some suggestions that may aid in achieving this goal. Full article

Cancer-associated cachexia is a multifaceted wasting syndrome characterized by progressive loss of skeletal muscle mass, systemic inflammation, and metabolic dysfunction and is particularly prevalent in gastrointestinal cancers. Physical activity has emerged as a promising non-pharmacological intervention capable of attenuating key drivers of cachexia. Exercise modulates inflammatory signaling (e.g., IL-6/STAT3 and TNF-α/NF-κB), enhances anabolic pathways (e.g., IGF-1/Akt/mTOR), and preserves lean body mass and functional capacity. Exercise-induced signaling molecules, known as exerkines, are key mediators of these benefits, which are released during physical activity and act in an autocrine, paracrine, and endocrine manner. However, many of these molecules also exhibit context-dependent effects. While they exert protective, anti-inflammatory, or anabolic actions when transiently elevated after exercise, the same molecules may contribute to cachexia pathogenesis when chronically secreted by tumors or in systemic disease states. The biological effects of a given factor depend on its origin, timing, concentration, and physiological milieu. This review presents recent evidence from clinical and experimental studies to elucidate how physical activity and exerkines may be harnessed to mitigate cancer cachexia, with particular emphasis on gastrointestinal malignancies and their unique metabolic challenges. Full article

The aim of the present observational study was to evaluate the early effect of free-form essential amino acid (EAA) supplementation on cardiac and muscular performance in elderly patients with chronic heart failure (HF) with reduced ejection fraction (HFrEF) and sarcopenia, as add-on to the optimized medical therapy (OMT) for HF. The present study included 60 elderly Caucasian patients suffering from HFrEF and sarcopenia. At the baseline and at follow-up, all patients underwent complete physical examination with the determination of the main anthropometric and hemodynamic parameters. After 6 months of supplementation with EAAs, we observed significant improvements in the parameters of sarcopenia. In addition, there was a significant improvement in glycol-metabolic parameters, and in inflammatory index as high sensitivity C-reactive protein (hs-CRP). In accordance with these results, significant decreases were observed in circulating levels of oxidative stress biomarkers Nox-2 (p < 0.001) and 8-Isoprostane (p < 0.001), and platelet aggregation biomarkers such as sP-Selectin (p < 0.001) and Gp-VI (p < 0.001). Of particular interest, after 6 months’ follow-up, there was a significant improvement in LVEF and global longitudinal strain (GLS). In conclusion, this study demonstrates that targeted nutritional intervention with EEAAs represents a viable therapeutic strategy for addressing the complex interplay between cardiac dysfunction and skeletal muscle wasting in elderly HF patients. Full article

Pancreatic cancer is frequently accompanied by cancer-associated cachexia, a debilitating metabolic syndrome marked by progressive skeletal muscle wasting and systemic metabolic dysfunction. This study presents a systems biology framework to simultaneously identify therapeutic targets for both pancreatic ductal adenocarcinoma (PDAC) and its associated cachexia (PDAC-CX), using cell-specific genome-scale metabolic models (GSMMs). The human metabolic network Recon3D was extended to include protein synthesis, degradation, and recycling pathways for key inflammatory and structural proteins. These enhancements enabled the reconstruction of cell-specific GSMMs for PDAC and PDAC-CX, and their respective healthy counterparts, based on transcriptomic datasets. Medium-independent metabolic biomarkers were identified through Parsimonious Metabolite Flow Variability Analysis and differential expression analysis across five nutritional conditions. A fuzzy multi-objective optimization framework was employed within the anticancer target discovery platform to evaluate cell viability and metabolic deviation as dual criteria for assessing therapeutic efficacy and potential side effects. While single-enzyme targets were found to be context-specific and medium-dependent, eight combinatorial targets demonstrated robust, medium-independent effects in both PDAC and PDAC-CX cells. These include the knockout of SLC29A2, SGMS1, CRLS1, and the RNF20–RNF40 complex, alongside upregulation of CERK and PIKFYVE. The proposed integrative strategy offers novel therapeutic avenues that address both tumor progression and cancer-associated cachexia, with improved specificity and reduced off-target effects, thereby contributing to translational oncology. Full article

Background: Duchenne muscular dystrophy (DMD) is a severe X-linked neuromuscular disorder caused by mutations in the DMD gene, leading to progressive muscle degeneration, loss of ambulation, and multi-systemic complications. Beyond its impact on mobility, DMD is associated with significant endocrine and metabolic dysfunctions that develop over time. Objective: To provide a comprehensive analysis of growth disturbances, endocrine dysfunctions, and metabolic complications in DMD including bone metabolism, considering the underlying mechanisms, clinical implications, and management strategies for daily clinical guidance. Methods: In this narrative review, an evaluation of the literature was conducted by searching the Medline database via the PubMed, Scopus, and Web of Science interfaces. Results: Growth retardation is a hallmark feature of DMD, with patients exhibiting significantly shorter stature compared to their healthy peers. This is exacerbated by long-term glucocorticoid therapy, which disrupts the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and delays puberty. Obesity prevalence follows a biphasic trend, with increased risk in early disease stages due to reduced mobility and corticosteroid use, followed by a decline in body mass index (BMI) in later stages due to muscle wasting. Metabolic complications, including insulin resistance, altered lipid metabolism, and hepatic steatosis, further characterize disease burden. Osteoporosis and increased fracture risk, primarily due to reduced mechanical loading and glucocorticoid-induced bone resorption, are major concerns, needing early screening and intervention. The RANK/RANKL/OPG signaling pathway has emerged as a critical factor in bone deterioration, providing potential therapeutic targets for improving skeletal health. Conclusions: Growth and endocrine disorders in DMD are complex and multifactorial, requiring proactive monitoring and early intervention. Addressing these issues requires a multidisciplinary approach integrating endocrine, nutritional, and bone health management. Further research is essential to refine treatment strategies that mitigate growth and metabolic disturbances while preserving overall patient well-being. Full article

Muscle loss unresponsive to nutritional supplementation affects up to 80% of cancer patients and severely reduces survival and treatment response. Exercise may help preserve muscle mass and function, yet the translatability of preclinical methods remains questionable. This study aimed to assess how voluntary wheel running, a clinically relevant physical activity, protects skeletal and cardiac muscle against cancer-mediated dysfunction and identify underlying molecular mechanisms. Methods: BALB/c mice were assigned to sedentary nontumor-bearing (SED+NT), sedentary tumor-bearing (SED+T), wheel run nontumor-bearing (WR+NT), and wheel run tumor-bearing (WR+T). Tumor-bearing groups received 5 × 10⁵ C26 cells; WR mice had wheel access for 4 weeks. Muscle function and tissue were analyzed for protective mechanisms. Results: SED+T mice exhibited significant fat and lean mass loss, indicating cachexia, which was prevented in WR+T mice. SED+T also showed 15% reduced grip strength and cardiac dysfunction, while WR+T preserved function. WR+T mice had lower expression of muscle wasting markers (Atrogin1, MuRF1, GDF15, GDF8/11). Physical activity also reduced tumor mass by 57% and volume by 37%. Conclusion: Voluntary wheel running confers tumor-suppressive, myoprotective, and cardioprotective effects. These findings support physical activity as a non-pharmacological strategy to combat cancer-related muscle wasting and dysfunction. Full article

Type 1 Diabetes Mellitus (T1D) is a disease characterized by the destruction of pancreatic beta cells. The subsequent loss of insulin production results in hyperglycemia, muscle wasting, and vascular dysfunction. Due to an inability to appropriately maintain glucose homeostasis, patients afflicted with T1D suffer from increased morbidity and early mortality. Skeletal muscle is the body’s largest metabolic reservoir, absorbing significant amounts of glucose from the bloodstream and physical exercise is known to improve and prevent the progression of pathological outcomes, but many T1D patients are unable to exercise at a level that conveys benefit. Thus, directly targeting muscle mass and function may prove beneficial for improving T1D patient outcomes, independent of exercise. A potent negative regulator of skeletal muscle has been identified as being upregulated in T1D patients, namely the myokine myostatin. Our hypothesis is that targeting myostatin (via genetic deletion) will prevent glucose dysfunction in a T1D model, preserve skeletal muscle function, and protect against vascular and renal dysfunction. Our methods utilized adult male mice with (WT) and without myostatin (Myo KO), in combination with the chemical induction of T1D (streptozotocin). Experimental outcomes included the assessment of glucose homeostasis (plasma glucose, HbA1c, IGTT), metabolism, muscle function (in vivo plantarflexion), and skeletal muscle vascular function (ex vivo pressure myography). Our results described systemic benefits from myostatin deletion in the T1D model, independent of insulin, including the following: inhibition of T1D-induced increases in plasma glucose, prevention of functional deficits in muscle performance, and preservation of fluid dynamics. Further, endothelial function was preserved with myostatin deletion. Taken together, these data inform upon the use of myostatin inhibition as a therapeutic target for effective treatment and management of the cardiometabolic and skeletal muscle dysfunction that occurs with T1D. Full article