Association Between Serum Iron Status and Muscle Mass in Adults: Results From NHANES 2015–2018

Sarcopenia and Frailty in Cirrhotic Patients: Evaluation of Prevalence and Risk Factors in a Single-Centre Cohort Study

Background and Objectives: Sarcopenia and frailty adversely affect morbidity and mortality in patients with liver cirrhosis. This study aimed to investigate the prevalence of sarcopenia and frailty in cirrhotic patients and to identify the contributing factors. Materials and Methods: This study was conducted in adult patients diagnosed with cirrhosis in a single-center cohort study who were under follow-up in the gastroenterology outpatient clinic. Patients were evaluated using the SARC-F questionnaire, FRAIL index, handgrip strength measurements, and various biochemical parameters. Results: Of the 100 patients included in the study, 58.7% were male, with a median age of 66.5 years. The prevalence of sarcopenia was 32%. Patients with sarcopenia had significantly lower body mass index (BMI) and higher model for end-stage liver disease (MELD)-Na and Child-Turcotte-Pugh (CTP) scores. According to the FRAIL scale, pre-frailty was highly prevalent among patients (60%). Significant negative correlations were observed between the SARC-F score and BMI, handgrip strength, albumin, vitamin D, and sodium levels. Conversely, significant positive correlations were identified between the SARC-F score and age, CTP score, MELD-Na score, bilirubin, AST, ALT, and ferritin levels. Conclusions: This study demonstrated a high prevalence of sarcopenia and frailty among cirrhotic patients. These findings warrants further investigation in longitudinal studies for hard clinical outcome and mortality.

Association of ultrasound signs of sarcopenia with serum ferritin levels and hepatic indices like NFS and FIB-4 in NAFLD patients

INTRODUCTION

Non-alcoholic fatty liver disease is one of the most common chronic diseases all around the world, which significantly correlates with metabolic disorders and inflammatory cycles. Sarcopenia is a decrease in the mass of skeletal muscles interacting with factors such as inflammatory processes and chronic diseases. It can also lead to the aggravation of chronic diseases.

METHOD

The study population was randomly selected and entered into the research based on exclusion and inclusion criteria. Non-alcoholic fatty liver disease was confirmed in all members of the study population by ultrasound. Patients' serum ferritin level was assessed, and their NFS and Fib 4 scores were calculated. Sarcopenia was diagnosed by measuring the thickness of the rectus femoris by ultrasonography. The correlation between these variables was evaluated and analyzed by statistical software.

RESULTS

According to statistical analysis, there is a significant association between the serum ferritin level and sarcopenia (P-value < 0.001). Besides, there is a significant association between NFS, Fib4, and sarcopenia (P-value = 0.024, 0.000).

CONCLUSION

This research's results reflect the correlation between serum ferritin and sarcopenia; however, it cannot conclude a cause-and-effect relationship between these variables.

Iron Chelation Prevents Age-Related Skeletal Muscle Sarcopenia in Klotho Gene Mutant Mice, a Genetic Model of Aging

BACKGROUND

A decline in skeletal muscle mass and function known as skeletal muscle sarcopenia is an inevitable consequence of aging. Sarcopenia is a major cause of decreased muscle strength, physical frailty and increased muscle fatigability, contributing significantly to an increased risk of physical disability and functional dependence among the elderly. There remains a significant need for a novel therapy that can improve sarcopenia and related problems in aging. Iron accumulation, especially catalytic iron (labile iron) through increased oxidative stress, could be one of the contributing factors to sarcopenia. Our study aimed to examine the effect of an iron chelator on age-related sarcopenia in mice.

METHODS

We investigated the effect of iron chelation (deferiprone, DFP) in sarcopenia, using mice with klotho deficiency (kl/kl), an established mouse model for aging. Four weeks old Klotho -/- male mice were treated with 25 mg/kg body weight of iron chelator deferiprone in drinking water for 8-14 weeks (n = 12/group, treated and untreated). At the end of the study, gastrocnemius, quadriceps and bicep muscles were dissected and used for western blot and immunohistochemistry analysis, histopathology and iron staining. Serum total iron, catalytic iron and cytokine ELISAs were performed with established methods.

RESULTS

Treatment with DFP significantly reduced loss of muscle mass in gastrocnemius and quadriceps muscles (p < 0.0001). Total and catalytic iron content of serum and iron in muscles were significantly (both p < 0.0001) lower in the treated animals. The inhibitory factor of myogenesis, the myostatin protein in gastrocnemius muscles (p = 0.019) and serum (p = 0.003) were downregulated after 8 weeks of therapy accompanied by an increased in muscle contractile protein myosin heavy chain (~2.9 folds, p = 0.0004). Treatment decreased inflammation (serum IL6 and TNFα) (p < 0.0001, p = 0.005), respectively, and elevated insulin-like growth factor levels (p = 0.472). This was associated with reduced DNA damage and reduced 8-hydroxy 2 deoxyguanosine in muscle and HO-1 protein (p < 0.001, p = 079), respectively. Significant weight loss (p < 0.001) and decreased water intake (p = 0.012) were observed in untreated mice compared to treatment group. Kaplan-Meier survival curves show the median life span of treated mice was 108 days as compared to 63 days for untreated mice (p = 0.0002).

CONCLUSIONS

In summary, our research findings indicate that deferiprone reduced age-related sarcopenia in the muscles of Klotho-/- mice. Our finding suggests chelation of excess iron could be an effective therapy to counter sarcopenia. However, additional studies are needed to evaluate and determine the efficacy in humans.

Micronutrient status, food security, anaemia, Plasmodium infection, and physical activity as predictors of primary schoolchildren's body composition in Côte d'Ivoire

Background

Stunting and overt malnutrition remain prevalent among school age children in rural areas of Côte d'Ivoire while obesity is increasing in urban areas. Associations of children's nutritional status, Plasmodium infection, physical activity and household characteristics with body composition were analyzed to identify what factors might be contributing to this dual burden of disease.

Methods

Longitudinal growth curve models (LGCM) evaluated associations of micronutrient status, household food security, Plasmodium falciparum prevalence and physical activity assessed at three time points with fat free mass and fat mass.

Results

More severe anaemia was inversely associated with FFM and TrFFM trajectories overall and among girls. P. falciparum infection had an indirect inverse association with FFM trajectories through anaemia among girls and through reductions of vitamin A directly associated with FFM. Changes in zinc concentrations were positively associated with FM trajectories overall and among boys. Food insecurity was inversely associated with FFM among boys from lower socio-economic status (SES) households while increased MVPA was associated with reduced fat mass among girls.

Conclusions

The integration of Malaria control programs with efforts to improve household healthy diet and promote physical activity can lead to improvements in body composition and overall child health and wellbeing.

Association between oxidative balance score and serum cobalt level in population with metal implants: a cross-sectional study from NHANES 2015-2020

Background

Growing evidence indicates that metal implants influence the body's oxidative stress status, which in turn affects the degradation and stability of metal implants. The oxidative balance score (OBS) is a composite indicator, reflecting the overall oxidative balance of pro-and antioxidants of the human body. However, the associations between OBS and the level of metal ions on the population with metal implants remain to be elucidated.

Methods

We conducted a cross-sectional study using data from 2015 to 2020 National Health and Nutrition Examination Survey (NHANES). Dietary and lifestyle factors closely associated with oxidative stress were quantified to calculate the OBS. Weighted multivariate logistic regression and smooth curve fittings were performed to examine the relationship between OBS and serum cobalt levels. Subgroup analyses were stratified by age and gender. In cases where non-linearity was detected, threshold effects were assessed using a two-piecewise linear regression model.

Results

A total of 549 participants were included in this analysis. The dietary OBS was negatively associated with serum cobalt level in fully adjusted model (β = -0.179, 95%CI: -0.358 to -0.001, P: 0.04918). Stratified by age and gender, negative correlation of OBS and dietary OBS with serum cobalt level was observed only in men and age over 70 years participants. Threshold effect analysis showed linear relationships between OBS, dietary OBS and cobalt level in males. There were non-linear relationships between OBS, dietary OBS and cobalt level in age over 70 years participants, with inflection points identified at 16.3 and 8.7 for OBS and dietary OBS, respectively.

Conclusion

Our study confirms the inverse relationships between oxidative stress and serum cobalt level in individuals with metal implants, highlighting the significance of optimizing OBS to mitigate the risk of metal ion toxicity. These findings emphasize the importance of maintaining an antioxidant diet and lifestyle, particularly as they offer greater protective effect for males and the elderly population.

Iron overload is positively associated with the incidence of osteoarthritis: A NHANES cross-sectional study

With the aging of the global population and the increase in the number of people with conditions such as obesity, the incidence of osteoarthritis (OA) is increasing annually. Clinical studies have shown that excessive accumulation of iron in joints is associated with age-related OA. However, there have been no reports on the relationship between iron metabolism and osteoarthritis. A STROBE-compliant cross-sectional observational study, was carried out and analyzed from the National Health and Nutrition Examination Survey from 2001 to 2020, including data on serum iron, transferrin saturation, serum ferritin, total iron-binding capacity, and transferrin receptors, as well as data on osteoarthritis. This cross-sectional study was conducted to explore the relationship between serum iron levels, osteoarthritis, and related metabolic factors. By adjusting the model and using quantile logistic regression models, the interaction between human body iron content and the aforementioned variables was analyzed. A total of 56,323 participants over 5 cycles were assessed for iron levels. After adjusting the model for age, sex, race, education level, marital status, total energy intake, physical activity, drinking, BMI, smoking, hypertension, and diabetes, we found that in different quantile regression results, serum iron was associated with OA, Q4: OR = 1.231 (95%CI: 1.009-1.501, P < .05). Ferritin is associated with OA, Q2: OR = 1.309 (95%CI: 1.012-1.692, P < .05); Q3: OR = 1.424 (95%CI: 1.129-1.797, P < .01); Q4: OR = 1.280 (95%CI: 1.013-1.616, P < .05). This cross-sectional study found that serum iron and transferrin saturation levels were positively correlated with OA incidence, suggesting that iron overload is a risk factor for OA. Large-sample prospective cohort studies are needed to confirm the correlation between iron overload and OA.

Association of serum iron metabolism with muscle mass and frailty in older adults: A cross-sectional study of community-dwelling older adults

This study aimed to explore the correlation between serum ferritin and additional biomarkers associated with iron metabolism, as well as their connection to muscle atrophy and frailty in the community-dwelling middle-aged and elderly population. The study included 110 middle-aged and elderly participants. Participants were categorized into an iron accumulation group (31 cases) and a normal iron group (79 cases) based on the standard ferritin values for men and women. Based on the criteria of the Asian Working Group on Muscular Dystrophy, participants were classified into a sarcopenia group (31 cases) and a non-sarcopenia group (79 cases). Using the Fried frailty syndrome criteria, participants were categorized into non-frailty (7 cases), pre-frailty (50 cases), and frailty (53 cases) groups. We employed multiple linear regression, binary logistic regression, partial correlation analysis, and ordinal logistic regression to assess the associations between iron metabolism indices and the presence of muscle atrophy and frailty. Compared with the normal iron group, the iron overload group had significantly higher ferritin, weight loss, fatigue, slow gait, and frailty scores (P < .05). Among the 3 models we set, ferritin was not significantly correlated with muscle mass in models 1 and 3 (P > .05), ferritin was positively correlated with muscle mass in model 2 (Pmodel2 = .048), but Transferrin saturation was positively correlated with muscle mass in all 3 models (Pmodel1 = .047, Pmodel2 = .026, Pmodel3 = .024). Ferritin, body mass index and iron overload were the influencing factors of sarcopenia (Pferritin = .027, PBMI < .001, Piron overload = .028). Ferritin was positively correlated with weight loss, fatigue, slow gait, frailty score, and frailty grade (P < .05). Age, gender and ferritin were the influencing factors of frailty classification (P < .05). Disrupted iron metabolism can lead to decreased muscle mass and function among the middle-aged and elderly, increasing frailty risk. It's crucial to prioritize community-based frailty screening and prevention, focusing on iron utilization as well as storage, since accelerating the body's iron metabolism cycle might influence muscle health more significantly than iron reserves.

Association between serum cotinine and muscle mass: results from NHANES 2011-2018

PURPOSE

Recently, the detrimental effect of cigarette smoking on muscle metabolism has attracted much attention, but the relationship between cigarette smoking and muscle mass is poorly understood. Thus, this study investigated the association between exposure to cigarette smoke, defined based on serum cotinine, and muscle mass in the US population.

METHODS

We utilized National Health and Nutrition Examination Survey (NHANES) data between 2011 and 2018 for analysis. Data on serum cotinine, muscle mass (quantified by appendicular skeletal muscle mass index, ASMI), and covariates were extracted and analyzed. Weighted multivariate linear regression analyses and smooth curve fittings were performed to investigate the association between serum cotinine and ASMI. Subgroup analyses were stratified by gender, race and smoking status. When nonlinearity was detected, the threshold effects were analyzed using a two-piecewise linear regression model.

RESULTS

In total, 8004 participants were included for analysis. The serum level of cotinine was negatively associated with ASMI in the fully adjusted model. Furthermore, comparing participants in the highest vs. the lowest tertile of serum cotinine, we found that ASMI decreased by 0.135 Kg/m2. In subgroup analysis stratified by gender and race, the association between serum cotinine and ASMI remained significant in all genders and races. In addition, the association remained significant among current and former smokers, but not among those who never smoked. Smooth curve fittings showed nonlinear relationships between serum cotinine and ASMI, with the inflection points identified at 356 ng/mL.

CONCLUSIONS

Our study revealed that serum cotinine was negatively related to muscle mass. This finding improves our understanding of the deleterious effects of cigarette smoking on muscle mass and highlights the importance of smoking cessation for muscle health.

Identification of three mechanistic pathways for iron-deficient heart failure

Current understanding of iron-deficient heart failure is based on blood tests that are thought to reflect systemic iron stores, but the available evidence suggests greater complexity. The entry and egress of circulating iron is controlled by erythroblasts, which (in severe iron deficiency) will sacrifice erythropoiesis to supply iron to other organs, e.g. the heart. Marked hypoferraemia (typically with anaemia) can drive the depletion of cardiomyocyte iron, impairing contractile performance and explaining why a transferrin saturation < ≈15%-16% predicts the ability of intravenous iron to reduce the risk of major heart failure events in long-term trials (Type 1 iron-deficient heart failure). However, heart failure may be accompanied by intracellular iron depletion within skeletal muscle and cardiomyocytes, which is disproportionate to the findings of systemic iron biomarkers. Inflammation- and deconditioning-mediated skeletal muscle dysfunction-a primary cause of dyspnoea and exercise intolerance in patients with heart failure-is accompanied by intracellular skeletal myocyte iron depletion, which can be exacerbated by even mild hypoferraemia, explaining why symptoms and functional capacity improve following intravenous iron, regardless of baseline haemoglobin or changes in haemoglobin (Type 2 iron-deficient heart failure). Additionally, patients with advanced heart failure show myocardial iron depletion due to both diminished entry into and enhanced egress of iron from the myocardium; the changes in iron proteins in the cardiomyocytes of these patients are opposite to those expected from systemic iron deficiency. Nevertheless, iron supplementation can prevent ventricular remodelling and cardiomyopathy produced by experimental injury in the absence of systemic iron deficiency (Type 3 iron-deficient heart failure). These observations, taken collectively, support the possibility of three different mechanistic pathways for the development of iron-deficient heart failure: one that is driven through systemic iron depletion and impaired erythropoiesis and two that are characterized by disproportionate depletion of intracellular iron in skeletal and cardiac muscle. These mechanisms are not mutually exclusive, and all pathways may be operative at the same time or may occur sequentially in the same patients.

A Population-Based and Clinical Cohort Validation of the Novel Consensus Definition of Metabolic Hyperferritinemia

CONTEXT

There is limited data on the clinical significance of metabolic hyperferritinemia (MHF) based on the most recent consensus.

OBJECTIVE

We aimed to validate the clinical outcomes of MHF in the general population and patients with biopsy-proven metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

The NHANES database and PERSONS cohort were included. MHF was defined as elevated serum ferritin with metabolic dysfunction (MD) and stratified into different grades according to ferritin (grade 1: 200 [females]/300 [males]-550 ng/mL; grade 2: 550-1000 ng/mL; grade 3: >1000 ng/mL). The clinical outcomes, including all-cause death, comorbidities, and liver histology, were compared between non-MHF and MHF in adjusted models.

RESULTS

In NHANES, compared with non-MHF with MD, MHF was related to higher risks of advanced fibrosis (P = .036), elevated albumin-creatinine ratio (UACR, P = .001), and sarcopenia (P = .013). Although the association between all grades of MHF and mortality was insignificant (P = .122), grades 2/3 was associated with increased mortality (P = .029). When comparing with non-MHF without MD, the harmful effects of MHF were more significant in mortality (P < .001), elevated UACR (P < .001), cardiovascular disease (P = .028), and sarcopenia (P < .001). In the PERSONS cohort, MHF was associated with more advanced grades of steatosis (P < .001), lobular inflammation (P < .001), advanced fibrosis (P = .017), and more severe hepatocellular iron deposition (P < .001).

CONCLUSION

Both in the general population and in at-risk individuals with MAFLD, MHF was related with poorer clinical outcomes.

Nanodrug Delivery Systems for Myasthenia Gravis: Advances and Perspectives

Myasthenia gravis (MG) is a rare chronic autoimmune disease caused by the production of autoantibodies against the postsynaptic membrane receptors present at the neuromuscular junction. This condition is characterized by fatigue and muscle weakness, including diplopia, ptosis, and systemic impairment. Emerging evidence suggests that in addition to immune dysregulation, the pathogenesis of MG may involve mitochondrial damage and ferroptosis. Mitochondria are the primary site of energy production, and the reactive oxygen species (ROS) generated due to mitochondrial dysfunction can induce ferroptosis. Nanomedicines have been extensively employed to treat various disorders due to their modifiability and good biocompatibility, but their application in MG management has been rather limited. Nevertheless, nanodrug delivery systems that carry immunomodulatory agents, anti-oxidants, or ferroptosis inhibitors could be effective for the treatment of MG. Therefore, this review focuses on various nanoplatforms aimed at attenuating immune dysregulation, restoring mitochondrial function, and inhibiting ferroptosis that could potentially serve as promising agents for targeted MG therapy.

Serum iron level is independently associated with sarcopenia: a retrospective study

Sarcopenia greatly reduces the quality of life of the elderly, and iron metabolism plays an important role in muscle loss. This study aimed to investigate the association between iron status and sarcopenia. A total of 286 adult patients hospitalized between 2019 and 2021 were included in this study, of which 117 were diagnosed with sarcopenia. Serum iron, total iron binding capacity (TIBC), transferrin, and transferrin saturation levels were compared between groups with and without sarcopenia and were included in the logistic analyses, with significant variables further included in the logistic regression model for the prediction of sarcopenia. Serum iron, TIBC, and transferrin levels decreased significantly in the sarcopenia group (p < 0.05), and were negatively associated with handgrip strength, relative skeletal muscle index, and multiple test performances (p < 0.05). Multivariate logistic analysis showed that sex, age, body mass index (BMI), and serum iron level were independent risk factors for sarcopenia. In the final logistic regression model, male sex (odds ratio [OR] 3.65, 95% confidence interval [CI] 1.67-7.98), age > 65 years (OR 5.40, 95% CI 2.25-12.95), BMI < 24 kg/m2 (OR 0.17, 95% CI 0.08-0.36), and serum iron < 10.95 μmol/L (OR 0.39, 95% CI 0.16-0.93) were included. Our study supported the impact of iron metabolism on muscle strength and performance.

Association between the oxidative balance score and low muscle mass in middle-aged US adults

Background

Oxidative Balance Score (OBS) is a tool for assessing the oxidative stress-related exposures of diet and lifestyle. The study aimed to investigate the association between OBS and low muscle mass.

Methods

Overall, 6,307 individuals over the age of 18 were assessed using data from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES). Weighted logistic regression and models were used, together with adjusted models.

Results

There was a negative relationship between OBS and low muscle mass [odds ratio (OR): 0.96, 95% confidence interval (CI): 0.94-0.97, p< 0.0001] using the first OBS level as reference. The values (all 95% CI) were 0.745 (0.527-1.054) for the second level, 0.650 (0.456-0.927) for the third level, and 0.326 (0.206-0.514) for the fourth level (P for trend <0.0001). Independent links with low muscle mass were found for diet and lifestyle factors. A restricted cubic spline model indicated a non-linear association between OBS and low muscle mass risk (P for non-linearity<0.05). In addition, the inflection points of the nonlinear curves for the relationship between OBS and risk of low muscle mass were 20.

Conclusion

OBS and low muscle mass were found to be significantly negatively correlated. By modulating oxidative balance, a healthy lifestyle and antioxidant rich diet could be a preventive strategy for low muscle mass.

Low hemoglobin levels are associated with compromised muscle health: Insights from a post-stroke rehabilitation cohort

AIM

There is limited evidence concerning the association between anemia and alterations in muscle health among hospitalized older patients. We aimed to evaluate the associations between baseline hemoglobin (Hb) levels and changes in muscle function in patients undergoing rehabilitation after stroke.

METHODS

This retrospective cohort study included consecutive hospitalized post-stroke patients. Data on serum Hb level were extracted from medical records on tests performed within 24 h of admission. The main outcomes were discharge score for the skeletal muscle mass index (SMI) obtained through bioimpedance analysis and the corresponding change in SMI during hospitalization. Other outcomes were handgrip strength (HGS) at discharge and the alteration in HGS during hospitalization. Multivariate linear regression analyses were used to determine the association between Hb levels at admission and outcomes of interest, adjusted for potential confounders.

RESULTS

Data from 955 patients (mean age 73.2 years; 53.6% men) were included in the analysis. The median Hb level at admission was 13.3 [11.9, 14.5] g/dL. After fully adjusting for confounding factors, the baseline Hb level was significantly and positively associated with SMI at discharge (β = 0.046, P = 0.039) and with SMI gain (β = 0.010, P = 0.039). Further, the baseline Hb level was independently and positively associated with HGS at discharge (β = 0.058, P = 0.014) and with its change from baseline (β = 0.100, P = 0.014).

CONCLUSION

Diminished baseline Hb levels were demonstrated be correlated with compromised muscle health in patients after stroke. Evaluating anemia at the outset serves as a crucial prognostic indicator. Geriatr Gerontol Int 2024; 24: 305-311.

Drug-related sarcopenia as a secondary sarcopenia

Sarcopenia has a significant impact on falls, physical function, activities of daily living, and quality of life in older adults, and its prevention and treatment are becoming increasingly important as the global population ages. In addition to primary age-related sarcopenia, activity-related sarcopenia, disease-related sarcopenia, and nutrition-related sarcopenia have been proposed as secondary sarcopenia. Polypharmacy and potentially inappropriate medication based on multiple diseases cause health problems in older patients. In some cases, drugs used for therapeutic or preventive purposes act on skeletal muscle as adverse drug reactions and induce sarcopenia. Although sarcopenia caused by these adverse drug reactions may be more common in older patients, in particular those taking many medications, drug-related sarcopenia has not yet received much attention. This review summarizes drugs that may induce sarcopenia and emphasizes the importance of drug-related sarcopenia as a secondary sarcopenia. Geriatr Gerontol Int 2024; 24: 195-203.

Association between serum copper levels and muscle mass: results from NHANES 2011-2016

Copper is essential for various biological processes. However, excess copper has several adverse health effects. The effects of serum copper on muscle mass are poorly understood. This study aimed to investigate the association between serum copper levels and muscle mass in the US population. We utilized National Health and Nutrition Examination Survey (NHANES) data between 2011 and 2016 for analysis. Data on serum copper, muscle mass (measured using the appendicular skeletal muscle mass index (ASMI)), and covariates were extracted and analyzed. Weighted multivariate linear regression analyses and smooth curve fittings were performed to investigate the association between serum copper levels and ASMI. Subgroup analyses stratified according to age and sex were performed. In the presence of nonlinearity, threshold effect analysis was performed using a two-piecewise linear regression model. A total of 3860 participants were included in the final analysis. Serum copper levels were negatively associated with ASMI in the fully adjusted model. Furthermore, by comparing participants in the highest and lowest tertiles of serum copper levels, we found that the ASMI decreased by 0.292 kg/m2. In the sex-stratified subgroup analysis, we observed an inverse association between serum copper levels and the ASMI in both men and women. When stratified by age, the association remained significant among participants < 40 years of age, but not among those ≥ 40 years old. Smooth curve fitting revealed a nonlinear relationship between serum copper and ASMI, with an inflection point identified at 150.6 μg/dL. Our study revealed an inverse relationship between serum copper levels and muscle mass. This finding improves the current knowledge on the impact of serum copper on muscle loss and highlights the importance of serum copper homeostasis in muscle health.

Evolving trends and burden of iron deficiency among children, 1990-2019: a systematic analysis for the global burden of disease study 2019

Objectives

We aimed to provide a timely, comprehensive, and reliable assessment of the burden of iron deficiency (ID) in children between 1990 and 2019 at the global, regional, and national levels to inform policymakers in developing locally appropriate health policies.

Methods

Data related to ID among children younger than 15 years old were analyzed by sex, age, year, socio-demographic index (SDI), and location according to the Global Burden of Disease Study 2019 (GBD 2019). Age-standardized rates were used to compare the burden between different regions and countries. Furthermore, the Joinpoint regression model was used to assess temporal trends from 1990 to 2019.

Results

In 2019, the number of prevalent cases and disability-adjusted life years (DALYs) for ID in children were 391,491,699 and 13,620,231, respectively. The global age-standardized prevalence and DALY rates for childhood ID in 2019 were 20,146.35 (95% confidence interval: 19,407.85 to 20,888.54) and 698.90 (466.54 to 1015.31) per 100,000, respectively. Over the past 30 years, the global prevalence of ID among children has been highest in low-SDI regions, particularly in Western Sub-Saharan Africa, South Asia, and Eastern Sub-Saharan Africa. Since 1990, the prevalence and DALY of ID in children have been declining in most geographic regions. Nationally, Ecuador, China, and Chile have shown the most significant decreases in prevalence. The greatest decline in age-standardized DALY rate was observed in Ecuador, while Burkina Faso experienced the highest increase. Bhutan had the highest prevalence and DALY rates in 2019. On the age level, the prevalence was relatively higher among the <5 years age group. At the gender dimension, the prevalence of ID in children overall was more pronounced in girls than in boys, as was the case for DALY.

Conclusion

Although the burden of ID in children has been declining, this disease remains a major public health problem, especially in countries with low SDI. Children younger than 5 years of age are an important group for whom targeted measures are needed to reduce the burden of ID.

Serum ferritin is associated with sarcopenia and predicts long-term survival for gastric cancer undergoing radical gastrectomy

BACKGROUND

Gastric cancer (GC) is one of the most common malignant tumors, and its long-term overall survival (OS) still needs to be improved. This study aimed to elucidate the relationship between serum ferritin (SF) and sarcopenia and its ability to predict long-term OS for GC patients.

METHODS

Clinicopathological data from GC patients who underwent radical gastrectomy were reviewed and received 3 years of follow-up after surgery. The correlation between SF and sarcopenia was determined by Spearman analysis. Factors used to establish a nomogram to predict the 3-year OS for GC were identified by multivariate Cox hazard analysis.

RESULTS

We retrospectively identified 372 GC patients after surgery and randomly divided (3:1) into a training cohort and a validation cohort. The correlation coefficient between SF and sarcopenia was 0.323. GC patients with SF < 151.5 μg/L had a significantly longer 3-year OS. The variables of the nomogram include SF, sarcopenia, TNM stage system, and neoadjuvant chemotherapy. In the training cohort and validation cohort, the area under the time-dependent ROC curve was 0.81 and 0.791, respectively. The calibration curve and decision curve in different cohorts have good consistency. 3-year OS was significantly different among the three groups (log-rank P  < 0.001) divided by calculating the nomogram score.

CONCLUSION

SF was positively correlated with sarcopenia, and the nomogram was a practical tool for predicting 3-year OS after radical gastrectomy, furthermore could be used to stratify the risk of 3-year OS in patients with GC.

Anemia and frailty in the aging population: implications of dietary fiber intake (findings of the US NHANES from 2007-2018)

BACKGROUND

Frailty has long been seen as an indicator of reduced physical functions in the elderly, which may be caused by a variety of chronic illnesses or cancerous tumors. Dietary fiber was connected with anemia and frailty, whereas it was uncertain if dietary fiber consumption modifies the impact of anemia on frailty in elderly adults.

METHODS

We performed a secondary analysis using older adults aged 60 years and over from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 cycles. Dietary fiber intake was estimated using two 24-h dietary recalls. Participants were dichotomized as frail or non-frail based on a modified Fried physical frailty phenotype from previous NHANES studies. The weighted logistic regression was used to estimate the odds ratio (OR) and confidence interval (CI) for the associations between hemoglobin levels and frailty at high- and low-dietary fiber intake levels.

RESULTS

A total of 9644 older adults were included in this study, and the weighted sample was 56,403,031, of whom 3,569,186 (6.3%) were deemed to be frail, and the remainder were deemed to be non-frail. Among the low dietary fiber intake group, higher hemoglobin was significantly associated with a lower risk of frailty (OR = 0.79, 95% CI: 0.71-0.87), and anemia was associated with an almost threefold elevated risk of frailty (OR = 3.24, 95% CI:1.98-5.29) in the fully adjusted model. However, this phenomenon was not observed in groups with high dietary fiber intake. In addition, L-shaped dose response relationship was found in the high dietary fiber intake group (P overall association < 0.001; P non-linear association = 0.076). Whereas the dose response relationship was not significant in the high dietary fiber intake group (P overall association 0.752; P non-linear association = 0.734).

CONCLUSIONS

Frailty was positively associated with the severity of anemia in older adults with low, but not high, dietary fiber intake. Adequate fiber intake may be an innovative dietary strategy to reduce frailty in older adults.

Iron deficiency is related to lower muscle mass in community-dwelling individuals and impairs myoblast proliferation

BACKGROUND

Loss of muscle mass is linked with impaired quality of life and an increased risk of morbidity and premature mortality. Iron is essential for cellular processes such as energy metabolism, nucleotide synthesis and numerous enzymatic reactions. As the effects of iron deficiency (ID) on muscle mass and function are largely unknown, we aimed to assess the relation between ID and muscle mass in a large population-based cohort, and subsequently studied effects of ID on cultured skeletal myoblasts and differentiated myocytes.

METHODS

In a population-based cohort of 8592 adults, iron status was assessed by plasma ferritin and transferrin saturation, and muscle mass was estimated using 24-h urinary creatinine excretion rate (CER). The relationships of ferritin and transferrin saturation with CER were assessed by multivariable logistic regression. Furthermore, mouse C2C12 skeletal myoblasts and differentiated myocytes were subjected to deferoxamine with or without ferric citrate. Myoblast proliferation was measured with a colorimetric 5-bromo-2'-deoxy-uridine ELISA assay. Myocyte differentiation was assessed using Myh7-stainings. Myocyte energy metabolism, oxygen consumption rate and extracellular acidification rate were assessed using Seahorse mitochondrial flux analysis, and apoptosis rate with fluorescence-activated cell sorting. RNA sequencing (RNAseq) was used to identify ID-related gene and pathway enrichment in myoblasts and myocytes.

RESULTS

Participants in the lowest age- and sex-specific quintile of plasma ferritin (OR vs middle quintile 1.62, 95% CI 1.25-2.10, P < 0.001) or transferrin saturation (OR 1.34, 95% CI 1.03-1.75, P = 0.03) had a significantly higher risk of being in the lowest age- and sex-specific quintile of CER, independent of body mass index, estimated GFR, haemoglobin, hs-CRP, urinary urea excretion, alcohol consumption and smoking status. In C2C12 myoblasts, deferoxamine-induced ID reduced myoblast proliferation rate (P-trend <0.001) but did not affect differentiation. In myocytes, deferoxamine reduced myoglobin protein expression (-52%, P < 0.001) and tended to reduce mitochondrial oxygen consumption capacity (-28%, P = 0.10). Deferoxamine induced gene expression of cellular atrophy markers Trim63 (+20%, P = 0.002) and Fbxo32 (+27%, P = 0.048), which was reversed by ferric citrate (-31%, P = 0.04 and -26%, P = 0.004, respectively). RNAseq indicated that both in myoblasts and myocytes, ID predominantly affected genes involved in glycolytic energy metabolism, cell cycle regulation and apoptosis; co-treatment with ferric citrate reversed these effects.

CONCLUSIONS

In population-dwelling individuals, ID is related to lower muscle mass, independent of haemoglobin levels and potential confounders. ID impaired myoblast proliferation and aerobic glycolytic capacity, and induced markers of myocyte atrophy and apoptosis. These findings suggest that ID contributes to loss of muscle mass.

Hemoglobin levels as a surrogate marker of sarcopenia in patients with liver cirrhosis

AIM

This study aimed to elucidate a surrogate marker of sarcopenia in patients with liver cirrhosis (LC).

METHODS

A total of 424 patients were assessed for handgrip strength (HGS) and skeletal muscle index (SMI). They were divided into two groups: sarcopenia (Group S; n = 80) and nonsarcopenia (Group NS; n = 344).

RESULTS

Group S showed significantly lower HGS, SMI, and hemoglobin (Hb) levels in males and female patients, and lower serum levels of albumin, cholinesterase, and zinc (all p < 0.001), along with significantly higher serum levels of procollagen type III-N-peptide and type IV collagen 7S-domain (p < 0.001 and p < 0.0017) than Group NS. The risk factors for sarcopenia were age 65 years or older, female gender, Child-Pugh class C, and Hb levels <10.9 g/dL in women and <12.4 g/dL in men (p = 0.012, p < 0.001, p = 0.031, and p < 0.001, respectively). Significant positive correlations were found between the Hb level and the SMI and HGS (r = 0.4, p < 0.001 and r = 0.4, p < 0.001, respectively). Sarcopenia, low HGS, and low SMI were significantly associated with overall survival in patients with LC (all p < 0.001). The predictive accuracy of Hb levels for predicting sarcopenia was significantly higher than for predicting SMI and tended to be higher than for predicting HGS (p = 0.014 and p = 0.059, respectively).

CONCLUSION

Hemoglobin levels are predictive of sarcopenia in patients with LC and warrants further investigation as a biomarker for sarcopenia in LC.

Association between systemic immune-inflammation index and low muscle mass in US adults: a cross-sectional study

BACKGROUND

Chronic inflammatory responses have been reported to be associated with low muscle mass and systemic immune-inflammation index(SII) is a novel indicator of inflammation. The purpose of our study was to clarify the relationship between SII and low muscle mass.

METHODS

This study was a cross-sectional study based on National Health and Nutrition Examination Survey (2011-2018). SII was calculated as the platelet count × neutrophil count/lymphocyte count. Appendicular skeletal muscle index was used to define low muscle mass. The individuals were divided into four groups by the quartile of SII (Q1-Q4). Multivariate weighted logistic regression analysis, smooth curve fitting and subgroup analysis were used to investigate the relationship between SII and sarcopenia. Subgroup analysis were based on demographic and clinical variables.

RESULTS

There were 10,367 individuals enrolled in our final analysis. The overall mean age was 39.39 years and 49.17% were males. The overall prevalence of low muscle mass in the study population was 8.77%. The smooth curve fitting analysis indicated a near-linear relationship between SII and low muscle mass. In multivariate weighted logistic regression analysis, the odds ratio (OR) of Q4 is 1.28 (95% CI, 1.16-1.40) for low muscle mass when compared to lowest quartile of the SII. In subgroup analysis, SII still increased the risk of low muscle mass independently.

CONCLUSION

The increased SII levels were associated with an increased risk of low muscle mass in a large population. Our study increased the understanding between inflammation and low muscle mass. Anti-inflammation therapy may be important for low muscle mass.

Hemoglobin and Endotoxin Levels Predict Sarcopenia Occurrence in Patients with Alcoholic Cirrhosis

Alcohol is a major risk factor of liver cirrhosis (LC). This study aimed to elucidate a surrogate marker of sarcopenia in patients with LC of different etiology. Out of 775 patients with LC, 451 were assessed for handgrip strength and skeletal muscle mass (by computed tomography). They were then divided into two groups: alcoholic cirrhosis (AC; n = 149) and nonalcoholic cirrhosis (NAC; n = 302). Endotoxin activity (EA) levels were measured with an EA assay. Group AC showed significantly higher platelet counts (p = 0.027) and lower blood urea nitrogen levels and fibrosis-4 index than group NAC (p = 0.0020 and p = 0.038, respectively). The risk factors of sarcopenia were age ≥ 65 years, female sex, CP-C LC, Hb levels < 12 g/dL, and EA level > 0.4 in all patients with LC; hemoglobin (Hb) levels < 12 g/dL and EA level > 0.4 in group AC; and age ≥ 65 years, CP-C LC, and Hb levels < 12 g/dL in group NAC. The prediction accuracy of Hb for sarcopenia in group AC, group NAC, and all patients was 83.6%, 75.9%, and 78.1% (sensitivity: 92.0%, 69.0%, and 80.2%; specificity: 66.4%, 71.0%, and 64.0%), respectively. Although not significant, the predictive performance was better when using the combination of Hb and EA measurements than when using Hb alone in group AC but was comparable in all patients. Hb levels can predict sarcopenia in patients with LC, but in those with AC, the combination of Hb and EA improves the prediction performance.

Bibliometric analysis of research trends in relationship between sarcopenia and surgery

Background

The relationship between sarcopenia and surgery has attracted an increasing number of researchers in recent years. Our study aimed to identify the current research hotspot and status in this field by using bibliometric and visualization analysis.

Methods

Publications about the relationship between sarcopenia and surgery that met the inclusion criteria were collected from the Science Citation Index Expanded. The bibliometric and visualized studies were performed using VOSviewer, and R.

Results

A total of 2,261 documents on the relationship between sarcopenia and surgery were included in our study. These articles were written by 13,757 authors from 2,703 institutions in 70 countries and were published in 772 journals. The USA is the most productive and influential country in this field (524 publications and 15,220 citations). The Udice French Research Universities was the most productive institution in this field (57 publications), and the University of Alberta had the largest number of citations. Annuals of Surgical Oncology published the most studies in this field. Shen Xian was the most productive author in this field (number of publications = 19), and Baracos Vickie was the most influential author, whose studies in this field had been cited 2,209 times. The cluster analysis was performed and visualized, and the keywords were classified into 6 clusters: Cluster 1 (body composition and nutrition), Cluster 2 (sarcopenia), Cluster 3 (malnutrition and cachexia), Cluster 4 (cancer surgery), Cluster 5 (elderly and frailty), Cluster 6 (neuromuscular scoliosis).

Conclusion

The relationship between sarcopenia and surgery was still a controversial and well-discussed topic in recent years. Our study showed that the study in this field mainly focused on sarcopenia, oncology surgery, orthopedics, and nutrition.