Common mouse models of chronic kidney disease are not associated with cachexia.

The 5/6 nephrectomy and adenine-induced nephropathy mouse models have been extensively used to study Chronic Kidney Disease (CKD)-related cachexia. One common caveat of these CKD models is the cross-sectional nature of comparisons made versus controls. We here performed a comprehensive longitudinal assessment of body composition and energy metabolism in both models. The most striking finding is that weight loss is largely driven by reduced food intake which promotes rapid loss of lean and fat mass. However, in both models, mice catch up weight and lean mass a few days after the surgery or when they are switched back to standard chow diet. Muscle force and mass are fully recovered and no sign of cachexia is observed. Our data demonstrate that the time-course of kidney failure and weight loss are unrelated in these common CKD models. These data highlight the need to reconsider the relative contribution of direct and indirect mechanisms to muscle wasting observed in CKD.

Impacts of fluid retention on prognostic abilities of cachexia diagnostic criteria in cancer patients with refractory cachexia.

BACKGROUND & AIMS: The international cancer cachexia criteria with a cutoff of 5% weight loss (WL) was proposed in Western patients. The Asian Working Group for Cachexia (AWGC) developed new criteria in Asian patients. The AWGC criteria are not cancer-specific and employ a cutoff of 2% WL. However, it is unclear whether both criteria are useful in patients with very advanced cancer because WL can be underestimated owing to fluid retention. Therefore, this study aimed to investigate the impacts of fluid retention on the prognostic abilities of both criteria in cancer patients with weeks of survival. METHODS: This study involved a secondary analysis of a prospective cohort study. The inclusion criteria constrained the study to adult patients with advanced cancer. Patients were divided into Non-cachexia and Cachexia groups using the international criteria and AWGC criteria. We performed time-to-event analyses using the Kaplan-Meier method and log-rank tests, and by conducting univariate and multivariate Cox regression analyses. RESULTS: A total of 402 patients were included in the analysis. Using the international criteria, the p-values for the log-rank test and stratified log-rank test for the mixed patients with and without fluid retention were 0.55 and 0.18, respectively. Using the AWGC criteria, the p-values for the log-rank test and stratified log-rank test for the mixed patients with and without fluid retention were 0.38 and 0.12, respectively. Without considering the impacts of fluid retention, no significant differences were observed between the Non-cachexia and Cachexia groups for both criteria. After adjusting for the status of fluid retention, significantly higher risks of mortality were not observed in the Cox proportional hazard model for the Cachexia group compared with the Non-cachexia group, for both criteria. However, significant associations were observed between fluid retention and overall survival. CONCLUSIONS: The international criteria and AWGC criteria lost their prognostic abilities in cancer patients with weeks of survival. Since measurements of %WL were significantly confounded by fluid retention, fluid retention-adjusted criteria for cachexia need to be developed for cancer patients with refractory cachexia.

Tryptophan metabolism and kynurenine metabolites in cancer: systemic nutritional and metabolic implications.

PURPOSE OF REVIEW: To describe the role of Tryptophan (Trp) metabolism and Kynurenine (Kyn) metabolites in nutritional and metabolic changes in cancer. RECENT FINDINGS: Trp is in part utilized for protein and neurotransmitters biosynthesis, but more than 95% is implicated in Kyn pathways. In this molecular cascade, metabolites are produced with distinct biological activities regulating the immune response and neurotransmission with potential implications in malnutrition/cachexia during cancer. Immune dysfunction is a phenomenon occurring during cancer and malnutrition. Kyn metabolites regulate lymphocytes activity and recent data in animals showed that the inhibition of indoleamine-2,3-dioxygenase (IDO) via 1-methyl-tryptophan determines partial amelioration of inflammation, but no positive effects on the preservation of muscularity were observed. Kynurenines seem to contribute to muscle catabolism via NAD+ biosynthesis and ROS generation. Trp metabolism via the serotonin biosynthesis is involved in appetite control in cancer. Moreover, kynurenines have a role in determining fatigue in conditions associated with inflammation. SUMMARY: Trp metabolism has implications in immune and energy balance in cancer. The modulation of Trp and kynurenines have impact on central nervous system mechanisms, including appetite, fatigue, and muscle wasting/cachexia. Research focusing on these clinical implications will open new scenario for therapeutic interventions aimed at counteracting nutritional derangements in cancer.

Nutrition Management in Geriatric Patients with CKD.

Sarcopenia, defined as age-related decline in skeletal muscle mass and functional capacity, is a hallmark nutritional abnormality observed in patients with moderate-to-advanced CKD. Uremic state and associated medical conditions also predispose older patients with CKD to protein-energy wasting, a nutritional abnormality that could include sarcopenia. Prevention of protein and energy depletion and replenishing the already low nutritional reserves elderly patients with CKD should focus on conventional and innovative strategies. This review aims to provide an overview of the mainstay of nutritional therapy in this patient population, such as intake of adequate amounts of protein and energy along with preserving fluid, electrolyte, and mineral balance, and to discuss more innovative interventions to aid these approaches.

A dose-response meta-analysis of randomized clinical trials investigating the effects of omega-3 supplementation on body weight in patients with cancer cachexia.

BACKGROUND: Cachexia is one of the side effects of cancer diseases that can be reduced weight, and lower overall survival. Weight loss has been associated with adverse outcomes in both cancer patients and patients with benign diseases. There is no definitive treatment for fully reverse cachexia. studies showed higher levels of inflammatory markers in patient with cachectic cancer. Therefore, this study aimed to investigate the dose-response effects of omega-3 as an anti-inflammatory supplement on body weight in patients with cancer cachexia. METHODS: Online databases including PubMed, Scopus, and Web of Science were systematically searched by relevant keywords up to January 2022. Random effect analysis was applied to perform meta-analysis. Subgroup analyses were performed to find heterogeneity sources. Quality assessment was conducted using Revised Cochrane Collaboration's tool II. Trim and fill analysis were also carried out in case of the presence of publication bias. The certainty in the evaluations was assessed by the GRADE approach. RESULTS: Omega-3 supplementation resulted in a significant increase of body weight in patients with cancer cachexia when the age of study participants was ≥67 years and the baseline weight of them was ≤60 kg (WMD = 0.99; 95 % CI: 0.06, 1.92 and WMD = 1.22; 95 % CI: 0.14, 2.30, respectively). Also, there was a non-significant linear relationship between the dosage of omega-3 supplementation and body weight in patients with cancer cachexia. CONCLUSION: Omega-3 supplementation may be a promising agent to increase body weight in patients with cancer cachexia. Also, a non-significant linear relationship between the dosage of omega-3 supplementation and body weight was found in these patients.

Modified Controlling Nutritional Status (mCONUT) serves as a promising prognostic factor in patients with cancer cachexia.

BACKGROUND: Malnutrition and systemic inflammation are considered 2 hallmarks of cancer cachexia. Our study aimed to construct a modified Controlling Nutritional Status by introducing C-reactive protein as an inflammatory parameter and investigate its prognostic value in patients with cancer cachexia. METHODS: This multicenter cohort study included 5221 patients with cancer, among whom 1719 were diagnosed with cachexia. Concordance index and receiver operating characteristic curves were used to compare prognostic values between the 2 systems. The primary outcome was overall survival, and comprehensive survival analyses were performed. The secondary outcomes were short-term survival, malnutrition, and quality of life. RESULTS: During the median follow-up of 17.47 mo, 813 deaths were recorded. The modified Controlling Nutritional Status was more accurate than Controlling Nutritional Status in predicting survival in patients with cancer cachexia. Patients in the high Controlling Nutritional Status/modified Controlling Nutritional Status group had a significantly shorter overall survival. Multivariate Cox analysis confirmed high Controlling Nutritional Status (hazard ratio = 1.34, 95% CI, 1.13-1.58; P < 0.001) and modified Controlling Nutritional Status (hazard ratio = 1.46; 95% CI, 1.26-1.69; P < 0.001) were independent risk factors for survival, adjusting for confounders. In subgroup analyses, a high modified Controlling Nutritional Status score had a significantly negative effect on survival in cachexia patients with upper gastrointestinal and colorectal cancer, especially for advanced-stage (stages III and IV) patients. The risk of short-term mortality and experiencing malnutrition rose to 1.48 and 1.13 times, respectively, in the high modified Controlling Nutritional Status group, as well as that for poorer life quality. CONCLUSION: The modified Controlling Nutritional Status group comprehensively reflects nutritional, immune, and inflammatory status and serves as a powerful prognostic scoring system in patients with cancer cachexia.

Heterogeneity of weight loss and transcriptomic signatures in pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is highly associated with cachexia and weight loss, which is driven by the tumour's effect on the body. Data are lacking on differences in these metrics based on PDAC anatomic location. We hypothesize that the primary tumour's anatomic region influences the prevalence and severity of unintentional weight loss. METHODS: Treatment naïve patients with PDAC who underwent pancreatectomy at a single institution between 2012 and 2020 were identified retrospectively. Patients with pancreatic head or distal tumours were matched by sex, age, N and T stage. Serologic and anthropometric variables were obtained at the time of diagnosis. Skeletal muscle index (SMI), muscle radiation attenuation (MRA) and adiposity were measured. The primary outcome was presence of significant weight loss [>5% body weight (BW) loss in past 6 months]. Signed rank tests, Cochran Mantel Haenszel tests and Kaplan-Meier survival analysis are presented. RNA-seq of tumours was performed to explore enriched pathways related to cachexia and weight loss. RESULTS: Pancreatic head tumours (n = 24) were associated with higher prevalence (70.8% vs. 41.7%, P = 0.081) and degree of weight loss (7.9% vs. 2.5%, P = 0.014) compared to distal tumours (n = 24). BMI (P = 0.642), SMI (P = 0.738) and MRA (P = 0.478) were similar between groups. Combining BW loss, SMI and MRA into a composite score, patients with pancreatic head cancers met more criteria associated with poor prognosis (P = 0.142). Serum albumin (3.9 vs. 4.4 g/dL, P = 0.002) was lower and bilirubin (4.5 vs. 0.4 mg/dL, P < 0.001) were higher with pancreatic head tumours. Survival differed by tumour location (P = 0.014) with numerically higher median overall survival with distal tumours (11.1 vs. 21.8 months; P = 0.066). Transcriptomic analysis revealed inactivation of appetite stimulation, weight regulation and nutrient digestion/metabolism pathways in pancreatic head tumours. CONCLUSIONS: Resectable pancreatic head PDAC is associated with higher prevalence of significant weight loss and more poor prognosis features. Pancreaticobiliary obstruction and hypoalbuminemia in patients with head tumours suggests compounding effects of nutrient malabsorption and systemic inflammation on molecular drivers of cachexia, possibly contributing to shorter survival. Therefore, PDAC-associated cachexia is a heterogenous syndrome, which may be influenced by the primary tumour location. Select patients with resectable pancreatic head tumours may benefit from nutritional rehabilitation to improve outcomes.

A comprehensive multiomics approach reveals that high levels of sphingolipids in cardiac cachexia adipose tissue are associated with inflammatory and fibrotic changes.

Cardiac cachexia is a deadly consequence of advanced heart failure that is characterised by the dysregulation of adipose tissue homeostasis. Once cachexia occurs with heart failure, it prevents the normal treatment of heart failure and increases the risk of death. Targeting adipose tissue is an important approach to treating cardiac cachexia, but the pathogenic mechanisms are still unknown, and there are no effective therapies available. Transcriptomics, metabolomics, and lipidomics were used to examine the underlying mechanisms of cardiac cachexia. Transcriptomics investigation of cardiac cachexia adipose tissue revealed that genes involved in fibrosis and monocyte/macrophage migration were increased and strongly interacted. The ECM-receptor interaction pathway was primarily enriched, as shown by KEGG enrichment analysis. In addition, gene set enrichment analysis revealed that monocyte chemotaxis/macrophage migration and fibrosis gene sets were upregulated in cardiac cachexia. Metabolomics enrichment analysis demonstrated that the sphingolipid signalling pathway is important for adipose tissue remodelling in cardiac cachexia. Lipidomics analysis showed that the adipose tissue of rats with cardiac cachexia had higher levels of sphingolipids, including Cer and S1P. Moreover, combined multiomics analysis suggested that the sphingolipid metabolic pathway was associated with inflammatory-fibrotic changes in adipose tissue. Finally, the key indicators were validated by experiments. In conclusion, this study described a mechanism by which the sphingolipid signalling pathway was involved in adipose tissue remodelling by inducing inflammation and fat fibrosis in cardiac cachexia.

A rapid, non-invasive, clinical surveillance for CachExia, sarcopenia, portal hypertension, and hepatocellular carcinoma in end-stage liver disease: the ACCESS-ESLD study protocol.

BACKGROUND: Liver cirrhosis, the advanced stage of many chronic liver diseases, is associated with escalated risks of liver-related complications like decompensation and hepatocellular carcinoma (HCC). Morbidity and mortality in cirrhosis patients are linked to portal hypertension, sarcopenia, and hepatocellular carcinoma. Although conventional cirrhosis management centered on treating complications, contemporary approaches prioritize preemptive measures. This study aims to formulate novel blood- and imaging-centric methodologies for monitoring liver cirrhosis patients. METHODS: In this prospective study, 150 liver cirrhosis patients will be enrolled from three Swedish liver clinics. Their conditions will be assessed through extensive blood-based markers and magnetic resonance imaging (MRI). The MRI protocol encompasses body composition profile with Muscle Assement Score, portal flow assessment, magnet resonance elastography, and a abbreviated MRI for HCC screening. Evaluation of lifestyle, muscular strength, physical performance, body composition, and quality of life will be conducted. Additionally, DNA, serum, and plasma biobanking will facilitate future investigations. DISCUSSION: The anticipated outcomes involve the identification and validation of non-invasive blood- and imaging-oriented biomarkers, enhancing the care paradigm for liver cirrhosis patients. Notably, the temporal evolution of these biomarkers will be crucial for understanding dynamic changes. TRIAL REGISTRATION: Clinicaltrials.gov, registration identifier NCT05502198. Registered on 16 August 2022. Link: https://classic. CLINICALTRIALS: gov/ct2/show/NCT05502198 .

Screening of key genes in the pathogenesis of muscle atrophy in CKD-PEW children based on RNA sequencing.

BACKGROUND: In children with CKD, Protein Energy Wasting (PEW) is common, which affects the outcome of children and is an important cause of poor prognosis. We are aiming to explore the pathogenesis of muscle wasting in CKD-PEW children. METHODS: Blood samples of 32 children diagnosed with chronic kidney disease (CKD) and protein energy wasting (PEW) in our hospital from January 2016 to June 2021 were collected. RNA sequencing and bioinformatics analysis were performed. RESULTS: Based on GO (Gene Ontology) functional enrichment analysis, KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis and differential gene expression analysis, a total of 25 CKD-PEW related genes were obtained including CRP, IL6, TNF, IL1B, CXCL8, IL12B, IL12A, IL18, IL1A, IL4, IL10, TGFB2, TGFB1, TGFB3, ADIPOQ, NAMPT, RETN, RETNLB, LEP, CD163, ICAM1, VCAM1, SELE, NF-κB1, NF-κB2. The most significantly differentially expressed gene was NF-κB2 (adjusted P = 2.81 × 10-16), and its expression was up-regulated by 3.92 times (corresponding log2FoldChange value was 1.979). Followed by RETN (adjusted P = 1.63 × 10-7), and its expression was up-regulated by 8.306 times (corresponding log2FoldChange value was 2.882). SELE gene were secondly significant (adjusted P = 5.81 × 10-7), and its expression was down-regulated by 22.05 times (corresponding log2FoldChange value was -4.696). CONCLUSIONS: A variety of inflammatory factors are involved in the pathogenesis of CKD-PEW in children, and chronic inflammation may lead to the development of muscle atrophy in CKD-PEW. It is suggested for the first time that NF-κB is a key gene in the pathogenesis of muscle wasting in CKD-PEW children, and its increased expression may play an important role in the pathogenesis of muscle wasting in children with CKD-PEW.

Exosomal EIF5A derived from Lewis lung carcinoma induced adipocyte wasting in cancer cachexia.

Cancer cachexia is a systemic inflammation-driven syndrome, characterized by muscle atrophy and adipose tissue wasting, with progressive weight loss leading to serious impairment of physiological function. Extracellular vesicles (EVs) derived from cancer cells play a significant role in adipocyte lipolysis, yet the mechanism remain uneclucidated. In this study, EVs derived from Lewis lung carcinoma (LLC) cells were extracted and characterized. 3T3-L1 and HIB1B adipocytes were cultured with conditioned medium or EVs from LLC, and LLC cells were used to establish a cancer cachexia mouse model. EVs derived from LLC cells were taken up by 3T3-L1 and HIB1B adipocytes, and derived exosomal EIF5A protein-induced lipolysis of adipocytes. High level of EIF5A was expressed in EVs from LLC cells, exosomal EIF5A is linked to lipid metabolism. Elevated expression of EIF5A is associated with shorter overall survival in lung cancer patients. Western blots, glycerol release and Oil red O staining assays were used to evaluate lipolysis of adipocytes. The reduction of lipolysis in 3T3-L1 and HIB1B adipocytes is achieved through silencing EIF5A or treating with pharmacologic inhibitor GC7 in vitro, and suppressing the expression of EIF5A in LLC cells by infected with shRNA or GC7 treatment partly alleviated white and brown adipose tissue lipolysis in vivo. Mechanistically, EIF5A directly binds with G protein-coupled bile acid receptor 1 (GPBAR1) mRNA to promote its translation and then activates cAMP response element binding protein (CREB) signaling pathway to induce lipolysis. This study demonstrates that exosomal EIF5A from LLC cells, with hypusinated EIF5A, has a lipolytic effect on adipocyte and adipose tissues in cancer cachexia model. Exosomal EIF5A could be involved in lipolysis and these findings indicate that a novel regulator and potential target for cachexia treatment.

The Contribution of Muscle Innate Immunity to Uremic Cachexia.

Protein energy wasting (PEW) is a common complication both in chronic kidney disease (CKD) and end-stage kidney disease (ESKD). Of note, PEW is one of the stronger predictors of morbidity and mortality in this patient population. The pathogenesis of PEW involves several mechanisms, including anorexia, insulin resistance, acidosis and low-grade inflammation. In addition, "sterile" muscle inflammation contributes to PEW at an advanced CKD stage. Both immune and resident muscle cells can activate innate immunity; thus, they have critical roles in triggering "sterile" tissue inflammation. Toll-like receptor 4 (TLR4) can detect endogenous danger-associated molecular patterns generated or retained in blood in uremia and induce a sterile muscle inflammatory response via NF-κB in myocytes. In addition, TLR4, though the activation of the NLRP3 inflammasome, links the sensing of metabolic uremic stress in muscle to the activation of pro-inflammatory cascades, which lead to the production of IL-1ß and IL-18. Finally, uremia-induced accelerated cell senescence is associated with a secretory phenotype that favors fibrosis in muscle. Targeting these innate immune pathways could lead to novel therapies for CKD-related PEW.

Micronutrient and Nutritional Status of HIV-Exposed and HIV-Unexposed Malawian Infants in the First Year of Life: Assessment of Ferritin, Vitamin A, and D Status and Its Association with Growth.

Breastfed Malawian infants from Human Immunodeficiency Virus (HIV)-uninfected and HIV-infected women who received antiretroviral therapy were followed until 12 months of age, allowing us to evaluate plasma levels of ferritin, vitamin A (as retinol-binding protein, RBP), and vitamin D (25(OH)D) at six months, as well as nutritional status and growth between six and 12 months. Ferritin and RBP levels were adjusted for inflammation. The study included 88 infants, 63 of whom were part of a recent cohort (2019-2021) that included 49 HIV-exposed but uninfected (HEU) and 14 HIV-unexposed and uninfected (HUU) infants, as well as 25 infants (all HEU) from an earlier cohort (2008-2011). No differences were observed between HEU and HUU infants regarding micronutrient levels, anthropometric indexes, growth, and rates of stunting, being underweight, or wasting. HEU infants from the earlier cohort, when compared to more recent HEU infants, had significantly worse anthropometric measures at six months and inferior growth between six and twelve months. Overall, ferritin deficiency involved 68.6% of infants, while vitamin A and vitamin D deficiency involved 8% and 1.2% of infants, respectively. Micronutrient deficiencies were not associated with HIV exposure, cohort, stunting, being underweight, or wasting. At six months, stunting, being underweight, and wasting involved 25.0%, 2.7% and 2.8% of infants, respectively, with no differences related to HIV exposure. Ferritin deficiency at six months was associated with inferior subsequent growth. In this small observational study conducted in Malawian infants, no major nutritional gap was observed between HIV-exposed and HIV-unexposed infants, though the study highlighted specific nutritional deficiencies that deserve attention. High rates of stunting and ferritin deficiency were observed in the first year of life in Malawian infants, irrespective of maternal HIV status; a significant association between ferritin deficiency and worse subsequent growth was found. Vitamin A and vitamin D deficiencies were much less frequent. Based on the data observed, nutritional interventions should give priority to the correction of ferritin deficiency and chronic undernutrition.

Understanding the gut microbiota in cancer cachexia.

PURPOSE OF REVIEW: Cachexia is a complex, multifactorial syndrome primarily characterized by weight loss, muscle wasting, anorexia, and systemic inflammation. It is prevalent in cancer patients and is associated with a poor prognosis, including lower resistance to intervention toxicity, quality of life, and survival, compared to patients without the syndrome. The gut microbiota and its metabolites have been shown to influence host metabolism and immune response. Our article reviews the current evidence suggesting a role of gut microbiota in the development and progression of cachexia, while discussing the potential mechanisms involved. We also describe promising interventions targeting gut microbiota aiming to improve outcomes related to cachexia. RECENT FINDINGS: Dysbiosis, an imbalance in gut microbiota, has been associated with cancer cachexia through pathways involving muscle wasting, inflammation, and gut barrier dysfunction. Interventions targeting gut microbiota, such as probiotics, prebiotics, synbiotics, and fecal microbiota transplantation, have shown promising results in managing this syndrome in animal models. However, evidence in humans is currently limited. SUMMARY: Mechanisms linking gut microbiota and cancer cachexia need to be further explored, and additional human research is necessary to evaluate the appropriate dosages, safety, and long-term outcomes of prebiotic and probiotic use in microbiota management for cancer cachexia.

Variable body and tissue weight reporting in preclinical cachexia literature may alter study outcomes and interpretation.

Cancer cachexia is a multifactorial syndrome of body weight loss, muscle wasting and progressive functional decline, affecting many advanced cancer patients and leading to worsened clinical outcomes. Despite inherent limitations of many preclinical cachexia models, including large tumor burden, rapid tumor growth and young age of animals, these animal models are widely used and imperative for the study of cachexia mechanisms and experimental therapeutics. However, there are currently no guidelines for the reporting and representation of data in preclinical cachexia literature. We examined the current state of data reporting in publications using the colon-26 adenocarcinoma (C26) model of cachexia and compared statistical differences in reporting mechanisms using animals from our laboratory. We show that data reporting and representation in C26 preclinical cachexia literature are diverse, making comparison of study outcomes difficult. Further, different expression of body and tissue weights in our animals led to differential statistical significance, which could significantly alter data interpretation. This study highlights a need for consistent data reporting in preclinical cancer cachexia literature to effectively compare outcomes between studies and increase translatability to the human condition.

An Exploratory Study on a New Method for Nutritional Status Assessment in Patients with Chronic Kidney Disease.

Malnutrition is a risk factor for disease progression and poor prognosis in chronic kidney disease (CKD). However, the complexity of nutritional status assessment limits its clinical application. This study explored a new method of nutritional assessment in CKD (stage 1-5) patients using the Subjective Global Assessment (SGA) as the gold standard and evaluated its applicability. The kappa test was used to analyze the consistency of the Renal Inpatient Nutrition Screening Tool (Renal iNUT) with SGA and protein-energy wasting. Logistic regression analysis was used to analyze the risk factors of CKD malnutrition and calculate the prediction probability of multiple indicators combined for the diagnosis of CKD malnutrition. The receiver operating characteristic curve of the prediction probability was drawn to evaluate its diagnostic efficiency. A total of 161 CKD patients were included in this study. The prevalence of malnutrition according to SGA was 19.9%. The results showed that Renal iNUT had a moderate consistency with SGA and a general consistency with protein-energy wasting. Age > 60 years (odds ratio, OR = 6.78), neutrophil-lymphocyte ratio > 2.62 (OR = 3.862), transferrin < 200 mg/dL (OR = 4.222), phase angle < 4.5° (OR = 7.478), and body fat percentage < 10% (OR = 19.119) were risk factors for malnutrition in patients with CKD. The area under the receiver operating characteristic curve of multiple indicators for the diagnosis of CKD malnutrition was 0.89 (95% confidence interval: 0.834-0.946, p < 0.001). This study demonstrated that Renal iNUT has good specificity as a new tool for the nutrition screening of CKD patients, but its sensitivity needs to be optimized. Advanced age, high neutrophil-lymphocyte ratio, low transferrin level, low phase angle, and low body fat percentage are risk factors for malnutrition in patients with CKD. The combination of the above indicators has high diagnostic efficiency in the diagnosis of CKD malnutrition, which may be an objective, simple, and reliable method to evaluate the nutritional status of patients with CKD.

Skeletal muscle omics signatures in cancer cachexia: perspectives and opportunities.

Cachexia is a life-threatening complication of cancer that occurs in up to 80% of patients with advanced cancer. Cachexia reflects the systemic consequences of cancer and prominently features unintended weight loss and skeletal muscle wasting. Cachexia impairs cancer treatment tolerance, lowers quality of life, and contributes to cancer-related mortality. Effective treatments for cancer cachexia are lacking despite decades of research. High-throughput omics technologies are increasingly implemented in many fields including cancer cachexia to stimulate discovery of disease biology and inform therapy choice. In this paper, we present selected applications of omics technologies as tools to study skeletal muscle alterations in cancer cachexia. We discuss how comprehensive, omics-derived molecular profiles were used to discern muscle loss in cancer cachexia compared with other muscle-wasting conditions, to distinguish cancer cachexia from treatment-related muscle alterations, and to reveal severity-specific mechanisms during the progression of cancer cachexia from early toward severe disease.

EDA2R-NIK signalling promotes muscle atrophy linked to cancer cachexia.

Skeletal muscle atrophy is a hallmark of the cachexia syndrome that is associated with poor survival and reduced quality of life in patients with cancer1. Muscle atrophy involves excessive protein catabolism and loss of muscle mass and strength2. An effective therapy against muscle wasting is currently lacking because mechanisms driving the atrophy process remain incompletely understood. Our gene expression analysis in muscle tissues indicated upregulation of ectodysplasin A2 receptor (EDA2R) in tumour-bearing mice and patients with cachectic cancer. Here we show that activation of EDA2R signalling promotes skeletal muscle atrophy. Stimulation of primary myotubes with the EDA2R ligand EDA-A2 triggered pronounced cellular atrophy by induction of the expression of muscle atrophy-related genes Atrogin1 and MuRF1. EDA-A2-driven myotube atrophy involved activation of the non-canonical NFĸB pathway and was dependent on NFκB-inducing kinase (NIK) activity. Whereas EDA-A2 overexpression promoted muscle wasting in mice, deletion of either EDA2R or muscle NIK protected tumour-bearing mice from loss of muscle mass and function. Tumour-induced oncostatin M (OSM) upregulated muscle EDA2R expression, and muscle-specific oncostatin M receptor (OSMR)-knockout mice were resistant to tumour-induced muscle wasting. Our results demonstrate that EDA2R-NIK signalling mediates cancer-associated muscle atrophy in an OSM-OSMR-dependent manner. Thus, therapeutic targeting of these pathways may be beneficial in prevention of muscle loss.

Decreased insulin-like growth factor-1 expression in response to mechanical loading is associated with skeletal muscle anabolic resistance in cancer cachexia.

OBJECTIVE: Cachexia is a systemic metabolic syndrome characterized by loss of body weight and skeletal muscle mass during chronic wasting diseases, such as cancer. Skeletal muscle in cancer cachexia is less responsive to anabolic factors including mechanical loading; however, the precise molecular mechanism is largely unknown. In this study, we examined the underlying mechanism of anabolic resistance in skeletal muscle in a cancer cachexia model. METHODS: CD2F1 mice (male, 8 weeks old) were subcutaneously transplanted (1 × 106 cells per mouse) with a mouse colon cancer-derived cell line (C26) as a model of cancer cachexia. Mechanical overload of the plantaris muscle by synergist tenotomy was performed during the 2nd week and the plantaris muscle was sampled at the 4th week following C26 transplantation. RESULTS: The hypertrophic response of skeletal muscle (increased skeletal muscle weight/protein synthesis efficiency and activation of mechanistic target of rapamycin complex 1 signaling) associated with mechanical overload was significantly suppressed during cancer cachexia. Screening of gene expression profile and pathway analysis using microarray revealed that blunted muscle protein synthesis was associated with cancer cachexia and was likely induced by downregulation of insulin-like growth factor-1 (IGF-1) and impaired activation of IGF-1-dependent signaling. CONCLUSIONS: These observations indicate that cancer cachexia induces resistance to muscle protein synthesis, which may be a factor for inhibiting the anabolic adaptation of skeletal muscle to physical exercise in cancer patients.

Association Between Adipokine Profile, Systemic Inflammation, Muscle and Protein Energy Wasting in Children With Chronic Kidney Disease.

OBJECTIVES: This cross-sectional study explores the association of adipokines and interleukin-6 (IL-6) with muscle and protein energy wasting (PEW) in children with chronic kidney disease (CKD). METHODS: We measured serum adiponectin, leptin, resistin and IL-6 in 53 patients with CKD stage 3-5. Lean tissue (LTI) and fat tissue index (FTI) were estimated by bioimpedance analysis spectroscopy. PEW was defined as muscle wasting [LTI adjusted to height age (LTI HA) z-score < -1.65 SD) and at least 2 of the following: reduced body mass [body mass index adjusted to height age (BMI HA) z-score < -1.65 SD), poor growth [height z-score < -1.88 SD], questionnaire-based decreased appetite, and serum albumin ≤3.8 g/dL. RESULTS: PEW, observed in 8 (15.1%) patients, was more prevalent in CKD stage 5 (P = .010). Among the adipokines, adiponectin, and resistin levels were significantly higher in CKD stage 5 (P < .001, P = .005). Adiponectin was correlated to LTI HA z-score (Rs = -0.417, P = .002), leptin to FTI z-score (Rs = 0.620, P < .001), while no correlation was observed between resistin and body composition parameters. Resistin was the only adipokine correlated to IL-6 (Rs = 0.513, P < .001). After adjustment for CKD stage and patient age, PEW was associated with adiponectin and IL-6 rise by 1 µg/mL and 10 pg/mL respectively (odds ratio (OR) 1.240, 95% confidence interval (CI) 1.040, 1.478 and OR 1.405, 95% CI 1.075-1.836) but not with leptin, while resistin association with PEW lost its significance. CONCLUSIONS: In pediatric CKD, adiponectin is associated with muscle wasting, leptin with adiposity and resistin with systemic inflammation. Adiponectin and cytokine IL-6 may serve as PEW biomarkers.