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.

The association of lipid metabolism and sarcopenia among older patients: a cross-sectional study.

Sarcopenia has become a heavy disease burden among the elderly. Lipid metabolism was reported to be involved in many degenerative diseases. This study aims to investigate the association between dysregulated lipid metabolism and sarcopenia in geriatric inpatients. This cross-sectional study included 303 patients aged ≥ 60, of which 151 were diagnosed with sarcopenia. The level of total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), homocysteine (HCY), BMI, and fat percentage, were compared between sarcopenia and non-sarcopenia patients. The Spearman correlation coefficient was used to estimate the association between sarcopenia and the level of lipid metabolism. To determine risk factors related to sarcopenia, a multivariate logistic regression analysis was carried out. Risk prediction models were constructed based on all possible data through principal component analysis (PCA), Logistic Regression (LR), Support Vector Machine (SVM), k-Nearest Neighbor (KNN), and eXtreme Gradient Boosting (XGboost). We observed rising prevalence of sarcopenia with increasing age, decreasing BMI, and fat percentage (p < 0.001, Cochran Armitage test). Multivariate logistic regression analysis revealed sarcopenia's risk factors, including older age, male sex, lower levels of BMI, TC, and TG, and higher levels of LDL and HCY (p < 0.05). The sarcopenia risk prediction model showed the risk prediction value of sarcopenia, with the highest area under the receiver operating curve (AUC) of 0.775. Our study provided thorough insight into the risk factors associated with sarcopenia. It demonstrated that an increase in lipid metabolism-related parameters (BMI, TG, TC), within normal reference ranges, may be protective against sarcopenia. The present study can illuminate the direction and significance of lipid metabolism-related factors in preventing sarcopenia.

Factors affecting sarcopenia in older patients with chronic diseases.

BACKGROUND: Sarcopenia is an age-related disease characterized by a progressive loss of systemic muscle mass and/or decreased muscle strength and physical function. The occurrence of sarcopenia in patients with chronic diseases will not only cause further deterioration of diseases and adverse clinical outcomes, but also lead to high medical cost, suggesting a necessity and a great significance to explore the associated factors of sarcopenia in chronic patients in order to improve their quality of life. This study aimed to investigate factors affecting sarcopenia among older hospitalized patients with chronic diseases. METHODS: A total of 121 older patients with chronic diseases admitted to the Department of Geriatrics of Affiliated Kunshan Hospital of Jiangsu University from May 2019 to April 2021 were enrolled. According to the diagnostic criteria of sarcopenia formulated by the Asian Working Group for Sarcopenia (AWGS), the subjects were divided into a sarcopenia group (n=57) and a non-sarcopenia group (n=64). We analyzed the associated factors including bone mineral density, nutritional biomarkers, hormone levels and inflammatory cytokines. RESULTS: Compared to the non-sarcopenia group, the sarcopenia group was of older average age (P<0.001), exhibited a lower body mass index (BMI) (P<0.001), a lower bone mineral density (BMD) of the femoral neck (P<0.01), and a higher incidence of osteoporosis. In terms of hematology, the sarcopenia group exhibited significantly lower serum iron and zinc levels (both P<0.05), a higher growth hormone (GH) level (P<0.05), a significantly lower IGF-1 level (P<0.01), and a lower level of iron (P<0.01). Poor nutritional status (assessed via measurement of albumin and prealbumin levels) positively correlated with sarcopenia (P<0.01). CONCLUSIONS: Sarcopenia is closely associated with aging, and has a close relationship with osteoporosis. Anemia, malnutrition, vitamin and trace element deficiencies, changes in hormone levels, and chronic inflammation are correlated with sarcopenia. Patients with these features above call for the screenig of sarcopenia. Additionally, these characteristics may help providing clues for further research on the pathogenesis and risk factors of sarcopenia, along with disease prevention and intervention.

Preparation of functionalized pectin through acylation with alkyl gallates: Experiments coupled with density functional theory.

The covalent grafting of alkyl gallates onto pectin using a lipase-catalyzed reaction in a tetrahydrofuran/aqueous medium process acylated pectin molecules with excellent antioxidant and antibacterial properties. The alkyl gallates including methyl, ethyl, and propyl gallates were enzymatically grafted onto pectin molecule, in order to study the effect of alkyl gallates on the functional modification of pectin. The grafting mechanism was analyzed by ultraviolet-visible spectrum (UV-Vis), Fourier transform infrared spectrum (FTIR), proton nuclear magnetic resonance (1HNMR), and density functional theory (DFT). Results suggested that lipase grafted 4-OH of alkyl gallate onto pectin by catalyzing esterification in organic/aqueous solution, and the grafting rate was affected by the length of alkyl chain of the gallates molecule. In vitro experiments, the acylated pectins exhibited stronger antioxidant activity in the DPPH test and ß-carotene bleaching test and were found to have obvious antimicrobial performance against Escherichia coli and Staphylococcus aureus.

Preparation of hydrogels based on pectin with different esterification degrees and evaluation of their structure and adsorption properties.

In this study, pectin (Pe) with different esterification degrees was used as raw materials to prepared hydrogel adsorbents via free radical polymerization. The effect of Pe esterification degree on hydrogel structure and adsorption performance was studied by FTIR, SEM and XPS characterization and copper ion adsorption experiment. The results demonstrated that the carboxyl group in the hydrogels was bonded to Cu2+ through electrostatic force and coordination, which was an important factor in its adsorption capacity. The hydrogels prepared from Pe with low esterification degree had finer pores and higher carboxyl content, so the adsorption capacity on both water and Cu2+ was stronger. The preparation of hydrogels from low-ester Pe was more conducive to the adsorption of copper ions. Besides, the adsorption behavior of the hydrogels on Cu2+ was investigated through the adsorption thermodynamics and kinetics. The results indicated that the adsorption kinetics of the hydrogels was in accordance with the quasi-second-order model. The adsorption of Cu2+ by hydrogels was the result of physical and chemical adsorption, which was endothermic under natural condition, and a higher temperature will result in more favorable spontaneous adsorption.

Effect of BDNF on airway inflammation in a rat model of COPD.

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. The present study aimed to investigate the effect of brain-derived neurotrophic factor (BDNF) on lung function and airway inflammation in a rat model of COPD. A rat model of COPD was established in this study, and anti-BDNF antibody was injected to observe the effect of BDNF on pulmonary function and airway inflammation. Lung function and hematoxylin and eosin staining analyses were performed. BDNF in the airway was examined using immunohistochemistry, western blotting and enzyme-linked immunosorbent assay. Levels of oxidant stress and inflammatory cytokines were measured. After long-term heavy cigarette exposure, pulmonary inflammation and emphysema were observed, while lung function had deteriorated in the COPD, COPD + anti-BDNF and COPD + normal saline groups. Levels of BDNF expression, malondialdehyde, tumor necrosis factor-α and interleukin-6 were increased in rats with COPD compared with control rats, while levels of superoxide dismutase and glutathione peroxidase were decreased. Anti-BDNF intervention improved airway inflammation. To conclude, anti-BDNF intervention could alleviate inflammation and improve any imbalance between oxidation and antioxidation in the airway.