Sarcopenia: definition, epidemiology, and pathophysiology

Change of skeletal muscle mass in cirrhotic patients with hypersplenism after partial splenic artery embolization

PURPOSE

Partial splenic artery embolization (PSAE) is an effective procedure for cirrhotic patients with hypersplenism. The aim of our study is to evaluate the effect of PSAE on skeletal muscle, and to identify the predictor for an improvement in skeletal muscle index (SMI) in cirrhotic patients with hypersplenism after PSAE.

MATERIALS AND METHODS

466 cirrhotic patients with hypersplenism underwent PASE between Dec 2013 and Mar 2022. Medical records and CT images of enrolled patients were analyzed.

RESULTS

105 cirrhotic patients with hypersplenism were enrolled. Sarcopenia was observed in 60.00 % (63/105) of these patients, 68.25 % (43/63) of male patients, and 31.75 % (20/63) of female patients. In cirrhotic patients, no significant change in the mean SMI at the third lumbar vertebra (L3) level after PSAE. In patients with sarcopenia, the L3 SMI increased from 36.77 cm2/m2 (baseline) to 43.38 cm2/m2 (P < 0.01), the L3 subcutaneous fat area (SFA) increased from 79.16 cm2 (baseline) to 103.52 cm2 (P < 0.01) at 12-month follow-up after PSAE. In patients without sarcopenia, the L3 SMI decreased from 58.38 cm2/m2 (baseline) to 49.44 cm2/m2 (P < 0.05), the L3 SFA increased from 89.63 cm2 (baseline) to 94.77 cm2 (P > 0.05) at 12-month follow-up after PSAE. Univariate and multivariate analysis demonstrated splenic infarction rate (OR: 0.01, P = 0.0032) and SMI (OR: 0.84, P < 0.001) were independent predictors for an improvement in skeletal muscle in patients with sarcopenia.

CONCLUSIONS

In cirrhotic patients with sarcopenia, an improvement in skeletal muscle and fat mass was observed after PSAE; splenic infarction rate and the L3 SMI before PSAE predicted an improvement in skeletal muscle index in patients with sarcopenia after PSAE.

Muscle aging and sarcopenia: The pathology, etiology, and most promising therapeutic targets

Sarcopenia is a progressive muscle wasting disorder that severely impacts the quality of life of elderly individuals. Although the natural aging process primarily causes sarcopenia, it can develop in response to other conditions. Because muscle function is influenced by numerous changes that occur with age, the etiology of sarcopenia remains unclear. However, recent characterizations of the aging muscle transcriptional landscape, signaling pathway disruptions, fiber and extracellular matrix compositions, systemic metabolomic and inflammatory responses, mitochondrial function, and neurological inputs offer insights and hope for future treatments. This review will discuss age-related changes in healthy muscle and our current understanding of how this can deteriorate into sarcopenia. As our elderly population continues to grow, we must understand sarcopenia and find treatments that allow individuals to maintain independence and dignity throughout an extended lifespan.

Physical activity intensity, frequency, duration, volume and the risk of possible sarcopenia in middle-aged and older adults

This study explored the association of physical activity (PA) from different dimensions including intensity, frequency, duration, and volume with possible sarcopenia (PSA), and established the PA cut-off value to identify PSA in middle-aged and older adults. The data in this study were from the China Health and Retirement Longitudinal Study in 2015. There were 7,957 adults aged over 45 years in the analysis. PA was assessed using a modified version of the International Physical Activity Questionnaire Short Form. Muscle strength and physical performance were measured to define PSA. Results showed that men spending at least 3 days each week, more than 10 min each time on vigorous-intensity PA, or a minimum of 933 Mets on total PA each week had a lower risk of PSA. In women, spending at least 3 days each week, more than 30 min each time on moderate-intensity PA, or taking at least 6 days each week, more than 120 min each time on low-intensity PA, or a minimum of 933 Mets on total PA each week was associated with a lower risk of PSA. In older adults (≥ 65 years), spending at least one day each week, more than 30 min each time on vigorous-intensity PA, or taking a minimum of 933 Mets on total PA each week was linked with a decreased risk of PSA. However, no significant associations were found between any PA dimensions and PSA in middle-aged adults (45-64 years). A receiver operating characteristic analysis showed that the PA cut-off value was 695 and 693 Mets each week for predicting PSA for men and women. The findings suggested that the intensity, frequency, duration, and weekly volume of PA is associated with the risk of PSA in middle-aged and older adults, and the association largely depends on sex and age. The PA cut-off value may be an early indication for a higher risk of sarcopenia.

Effect of psoas muscle index on early postoperative outcomes in surgically treated spinal tumours in an Asian population

BACKGROUND

Sarcopenia has been purported to be a pre-operative risk factor that affects patient outcomes in oncological surgery, but no study as of yet has investigated the effect of sarcopenia in patients with spinal tumours. Psoas muscle measurements, including the psoas muscle index (PMI), are an objective way to determine sarcopenia.

OBJECTIVES

We investigated if PMI could predict post-operative outcomes (length of hospital stay and post-operative complications) in surgically treated spinal tumour patients in a multi-ethnic Asian population.

METHODS

We conducted a retrospective cohort study of patients with spinal tumours who underwent surgery at our tertiary institution from January 2016 to January 2020. PMI was measured on T2-weighted MRI sequences, at the middle of the L3 vertebral body and measurements were collected by 2 independent raters. The primary outcome was length of hospital stay (LOS), and the secondary outcome was post-operative complications. ROC curve was used to attain the cut-off value for PMI and the population was then stratified into 2 groups; sarcopenic if PMI was less than 1.22 and non-sarcopenic if the PMI value was more than or equal to 1.22. Multivariable linear regression was used for LOS, while multivariate logistic regression was used for complications.

RESULTS

57 patients were included with a mean length of stay of 17.8 days (SD 25.1) and the total number of patients with complications were 20 (35.1 %). Mean LOS was significantly higher in the sarcopenic group compared to the non-sarcopenic group. Univariate analysis confirmed the association of lower psoas muscle index corresponding with longer lengths of stay and this was corroborated in a multivariable linear regression model. There were no significant associations between PMI and postoperative complications.

CONCLUSIONS

Lower PMI values were significantly associated with a longer LOS. PMI may be warranted for risk stratifying Asian spinal tumour patients undergoing surgery.

Assessment of lumbar paraspinal muscle morphology using mDixon Quant magnetic resonance imaging (MRI): a cross-sectional study in healthy subjects

Background

Lumbar paraspinal muscles (LPM) are a part of the deep spinal stabilisation system and play an important role in stabilising the lumbar spine and trunk. Inadequate function of these muscles is thought to be an essential aetiological factor in low back pain, and several neuromuscular diseases are characterised by dysfunction of LPM. The main aims of our study were to develop a methodology for LPM assessment using advanced magnetic resonance imaging (MRI) methods, including a manual segmentation process, to confirm the measurement reliability, to evaluate the LPM morphological parameters [fat fraction (FF), total muscle volume (TMV) and functional muscle volume (FMV)] in a healthy population, to study the influence of physiological factors on muscle morphology, and to build equations to predict LPM morphological parameters in a healthy population.

Methods

This prospective cross-sectional observational comparative single-centre study was conducted at the University Hospital in Brno, enrolling healthy volunteers from April 2021 to March 2023. MRI of the lumbar spine and LPM (erector spinae muscle and multifidus muscle) were performed using a 6-point Dixon gradient echo sequence. The segmentation of the LPM and the control muscle (psoas muscle) was done manually to obtain FF and TMV in a range from Th12/L1 to L5/S1. Intra-rater and inter-rater reliability were evaluated. Linear regression models were constructed to assess the effect of physiological factors on muscle FF, TMV and FMV.

Results

We enrolled 90 healthy volunteers (median age 38 years, 45 men). The creation of segmentation masks and the assessment of FF and TMV proved reliable (Dice coefficient 84% to 99%, intraclass correlation coefficient ≥0.97). The univariable models showed that FF of LPM was influenced the most by age (39.6% to 44.8% of variability, P<0.001); TMV and FMV by subject weight (34.9% to 67.6% of variability, P<0.001) and sex (24.7% to 64.1% of variability, P<0.001). Multivariable linear regression models for FF of LPM included age, body mass index and sex, with R-squared values ranging from 45.4% to 51.1%. Models for volumes of LPM included weight, age and sex, with R-squared values ranged from 37.4% to 76.8%. Equations were developed to calculate predicted FF, TMV and FMV for each muscle.

Conclusions

A reliable methodology has been developed to assess the morphological parameters (biomarkers) of the LPM. The morphological parameters of the LPM are significantly influenced by physiological factors. Equations were constructed to calculate the predicted FF, TMV and FMV of individual muscles in relation to anthropometric parameters, age, and sex. This study, which presented LPM assessment methodology and predicted values of LPM morphological parameters in a healthy population, could improve our understanding of diseases involving LPM (low back pain and some neuromuscular diseases).

Bone-muscle crosstalk under physiological and pathological conditions

Anatomically connected bones and muscles determine movement of the body. Forces exerted on muscles are then turned to bones to promote osteogenesis. The crosstalk between muscle and bone has been identified as mechanotransduction previously. In addition to the mechanical features, bones and muscles are also secretory organs which interact closely with one another through producing myokines and osteokines. Moreover, besides the mechanical features, other factors, such as nutrition metabolism, physiological rhythm, age, etc., also affect bone-muscle crosstalk. What's more, osteogenesis and myogenesis within motor system occur almost in parallel. Pathologically, defective muscles are always detected in bone associated diseases and induce the osteopenia, inflammation and abnormal bone metabolism, etc., through biomechanical or biochemical coupling. Hence, we summarize the study findings of bone-muscle crosstalk and propose potential strategies to improve the skeletal or muscular symptoms of certain diseases. Altogether, functional improvement of bones or muscles is beneficial to each other within motor system.

Grip strength buffers the harmful association between multimorbidity and depression among middle-aged and older adults

BACKGROUND

Grip strength (GS) is associated to both multimorbidity and depression, however its possible moderating effect is unknown. This study aimed to investigate GS moderating effect on the association between multimorbidity and depression.

METHODS

Data from SHARE wave 8 was used. Participant were 41457 middle-aged and older adults (17954 men) from 18 European countries. A regression analysis was conducted for the moderating effect of sex- and age-specific GS quartiles (W) on the association between number of chronic diseases (X1) or multimorbidity (X2) and depression symptoms (Y).

RESULTS

More chronic diseases were associated with greater depressive symptomatology (men: B = 0.39, 95 % CI: 0.35, 0.42; women: B = 0.42, 95 % CI: 0.39, 0.45). On the other hand, being in a higher GS quartile was associated with fewer depression symptoms, and this association was stronger the higher the quartile was. Having a higher GS represented a decrease in depression symptoms associated with multimorbidity for men (quartile 1: B = 0.85, 95 % CI = 0.74, 0.95 vs. quartile 4: B = 0.49, 95 % CI = 0.38, 0.61) and women (quartile 1: B = 1.08, 95 %CI = 0.97, 1.19 vs. quartile 4: B = 0.59, 95 %CI: 0.47, 0.70).

CONCLUSIONS

Strategies aiming to reduce the impact of multimorbidity on mental health should promote muscle-strengthening physical activity among middle-aged and older adults.

Prevalence and predictive value of sarcopenia in hospitalized patients with ischemic colitis

Ischemic colitis (IC) and sarcopenia are associated with aging and multiple comorbidities. We aimed to investigate the prevalence and predictive role of sarcopenia in patients with IC. We retrospectively analyzed 225 hospitalized patients (median age, 72 years; women, 67.1%; severe IC, 34.2%) who were diagnosed with IC between January 2007 and February 2022. Sarcopenia was defined as the skeletal muscle index at the third lumbar vertebra determined by computed tomography. It was present in 49.3% (n = 111) of the patients and was significantly associated with severe IC compared to those without sarcopenia (48.6% vs. 20.2%, P < 0.001). Sarcopenia was associated with extended hospitalization (median: 8 vs. 6 days, P < 0.001) and fasting periods (4 vs. 3 days, P = 0.004), as well as prolonged antibiotic use (9 vs. 7 days, P = 0.039). Sarcopenia was linked to a higher risk of surgery or mortality (9.0% vs. 0%, P = 0.001) and independently predicted this outcome (odds ratio [OR], 11.17; 95% confidence interval [CI], 1.24‒1467.65, P = 0.027). It was prevalent among hospitalized patients with IC, potentially indicating severe IC and a worse prognosis. This underscores the importance of meticulous monitoring, immediate medical intervention, and timely surgical consideration.

3D Mitochondrial Structure in Aging Human Skeletal Muscle: Insights into MFN-2 Mediated Changes

Age-related atrophy of skeletal muscle, is characterized by loss of mass, strength, endurance, and oxidative capacity during aging. Notably, bioenergetics and protein turnover studies have shown that mitochondria mediate this decline in function. Although exercise has been the only therapy to mitigate sarcopenia, the mechanisms that govern how exercise serves to promote healthy muscle aging are unclear. Mitochondrial aging is associated with decreased mitochondrial capacity, so we sought to investigate how aging affects mitochondrial structure and potential age-related regulators. Specifically, the three-dimensional (3D) mitochondrial structure associated with morphological changes in skeletal muscle during aging requires further elucidation. We hypothesized that aging causes structural remodeling of mitochondrial 3D architecture representative of dysfunction, and this effect is mitigated by exercise. We used serial block-face scanning electron microscopy to image human skeletal tissue samples, followed by manual contour tracing using Amira software for 3D reconstruction and subsequent analysis of mitochondria. We then applied a rigorous in vitro and in vivo exercise regimen during aging. Across 5 human cohorts, we correlate differences in magnetic resonance imaging, mitochondria 3D structure, exercise parameters, and plasma immune markers between young (under 50 years) and old (over 50 years) individuals. We found that mitochondria we less spherical and more complex, indicating age-related declines in contact site capacity. Additionally, aged samples showed a larger volume phenotype in both female and male humans, indicating potential mitochondrial swelling. Concomitantly, muscle area, exercise capacity, and mitochondrial dynamic proteins showed age-related losses. Exercise stimulation restored mitofusin 2 (MFN2), one such of these mitochondrial dynamic proteins, which we show is required for the integrity of mitochondrial structure. Furthermore, we show that this pathway is evolutionarily conserved as Marf, the MFN2 ortholog in Drosophila, knockdown alters mitochondrial morphology and leads to the downregulation of genes regulating mitochondrial processes. Our results define age-related structural changes in mitochondria and further suggest that exercise may mitigate age-related structural decline through modulation of mitofusin 2.

Development and validation of a reliable method for automated measurements of psoas muscle volume in CT scans using deep learning-based segmentation: a cross-sectional study

OBJECTIVES

We aimed to develop an automated method for measuring the volume of the psoas muscle using CT to aid sarcopenia research efficiently.

METHODS

We used a data set comprising the CT scans of 520 participants who underwent health check-ups at a health promotion centre. We developed a psoas muscle segmentation model using deep learning in a three-step process based on the nnU-Net method. The automated segmentation method was evaluated for accuracy, reliability, and time required for the measurement.

RESULTS

The Dice similarity coefficient was used to compare the manual segmentation with automated segmentation; an average Dice score of 0.927 ± 0.019 was obtained, with no critical outliers. Our automated segmentation system had an average measurement time of 2 min 20 s ± 20 s, which was 48 times shorter than that of the manual measurement method (111 min 6 s ± 25 min 25 s).

CONCLUSION

We have successfully developed an automated segmentation method to measure the psoas muscle volume that ensures consistent and unbiased estimates across a wide range of CT images.

Effect of Sarcopenic Obesity on Weight Loss Outcomes and Quality of Life after Laparoscopic Sleeve Gastrectomy: A Retrospective Cohort Study

BACKGROUND

Sarcopenic obesity may affect the health outcome of people with obesity after laparoscopic sleeve gastrectomy (LSG). To assess the impact of sarcopenic obesity (SO) on weight loss outcomes and improvement of quality of life after LSG.

MATERIALS AND METHODS

This observational study included patients who underwent LSG with SO (99 patients) or without SO (146 patients) from a single center. The primary endpoint was weight loss and disease-specific quality of life in patients with or without SO after the operation. Fat-free mass (FFM) and fat mass (FM) were calculated based on the L3-level images of preoperative CT scans. SO was diagnosed if FM/FFM ≥ 0.80.

RESULTS

Operative time and postoperative hospital stay days were longer in the SO group (p < 0.001). After LSG, weight, BMI, and EBMI were significantly lower in the NSO group than in the SO group (all P < 0.05), while %EWL and the number of patients with %EWL ≥ 100% were significantly lower in the SO group (both p < 0.05). The total BAROS scores of patients in the NSO group were higher than those in the SO group (p < 0.05). Additionally, the MA II questionnaire assessment showed a lower percentage of "very good" and "good" outcomes in the SO group (p < 0.05).

CONCLUSIONS

Patients with SO take a slower rate, longer time to reach the ideal weight, and lower quality of life self-ratings than NSO patients after LSG. Thus, preoperative evaluation and tailoring rehabilitation guidance for people with SO should be accounted.

Active vitamin D treatment in the prevention of sarcopenia in adults with prediabetes (DPVD ancillary study): a randomised controlled trial

BACKGROUND

Observational studies show inverse associations between serum 25-hydroxyvitamin D concentrations and sarcopenia incidence; however, it remains unclear whether treatment with vitamin D prevents its development. We aimed to assess whether treatment with active vitamin D (eldecalcitol [0·75 μg per day]) can reduce the development of sarcopenia among adults with prediabetes.

METHODS

This randomised, double-blind, placebo-controlled, multicenter trial as an ancillary study was conducted at 32 clinics and hospital sites in Japan. Participants were assigned (1:1) by using a central randomisation method in which a randomisation list was made for each hospital separately using a stratified permuted block procedure. The primary endpoint was sarcopenia incidence during 3 years in the intention-to-treat population defined as weak handgrip strength (<28 kg for men and <18 kg for women) and low appendicular skeletal muscle index (<7·0 kg/m2 for men and <5·7 kg/m2 for women in bioelectrical impedance analysis). Although the usual criterion of hypercalcaemia was 10·4 mg/dL (2·6 mmol/L) or higher, hypercalcaemia that was enough to discontinue the study was defined as 11·0 mg/dL or higher. This study is registered with the UMIN clinical trials registry, UMIN000005394.

FINDINGS

A total of 1094 participants (548 in the eldecalcitol group and 546 in the placebo group; 44·2% [484 of 1094] women; mean age 60·8 [SD 9·2] years) were followed up for a median of 2·9 (IQR 2·8-3·0) years. Eldecalcitol treatment as compared with placebo showed statistically significant preventive effect on sarcopenia incidence (25 [4·6%] of 548 participants in the eldecalcitol group and 48 [8·8%] of 546 participants in the placebo group; hazard ratio 0·51; 95% CI 0·31 to 0·83; p=0·0065). The incidence of adverse events did not differ between the two groups.

INTERPRETATION

We found that treatment with eldecalcitol has the potential to prevent the onset of sarcopenia among people with prediabetes via increasing skeletal muscle volume and strength, which might lead to a substantial risk reduction of falls.

FUNDING

Kitakyushu Medical Association.

TRANSLATION

For the Japanese translation of the abstract see Supplementary Materials section.

Potential nutritional strategies to prevent and reverse sarcopenia in aging process: Role of fish oil-derived ω-3 polyunsaturated fatty acids, wheat oligopeptide and their combined intervention

INTRODUCTION

Nutritional support is potentially considered an essential step to prevent muscle loss and enhance physical function in older adults.

OBJECTIVES

This study aimed to assess the role of potential nutritional strategies, i.e., fish oil-derived ω-3 polyunsaturated fatty acids (PUFAs), wheat oligopeptide and their combined intervention, in preventing and reversing sarcopenia in aging process.

METHODS

One hundred 25-month-old Sprague-Dawley rats were randomly divided into 10 groups, and 10 newly purchased 6-month-old rats were included in young control group (n = 10). Fish oil (200, 400 or 800 mg/kg body weight), wheat oligopeptide (100, 200 or 400 mg/kg body weight), fish oil + wheat oligopeptide (800 + 100, 400 + 200 or 200 + 400 mg/kg body weight) or the equal volume of solvent were administered daily by gavage for 10 weeks. The effects of these interventions on natural aging rats were evaluated.

RESULTS

All intervention groups had a significant increase in muscle mass and grip strength and reduction in perirenal fat weight when compared to the aged control group (P < 0.05). The results of biochemical parameters, magnetic resonance imaging, proteomics and western blot suggested that the combination of wheat oligopeptide and fish oil-derived ω-3 PUFA, especially group WFM 2 (400 + 200 mg/kg body weight fish oil + wheat oligopeptide), was found to be more effective against aging-associated muscle loss than single intervention. Additionally, the interventions ameliorated fatty infiltration, muscle atrophy, and congestion in the intercellular matrix, and inflammatory cell infiltration in muscle tissue. The interventions also improved oxidative stress, anabolism, hormone levels, and inflammatory levels of skeletal muscle.

CONCLUSIONS

The combination of fish oil-derived ω-3 PUFA and wheat oligopeptide was found to be a promising nutritional support to prevent and reverse sarcopenia. The potential mechanism involved the promotion of protein synthesis and muscle regeneration, as well as the enhancement of muscle strength.

Exploring temporal trends and burden of traumatic shoulder dislocation: a global perspective

Objective

To explore the geographical and temporal trends of traumatic shoulder dislocation, describe the association between the social and demographic factors and the health burden due to traumatic shoulder dislocation, and further investigate its causes.

Methods

Data on traumatic shoulder dislocation was collected from the Global Burden of Disease 2019, spanning the years 1990 to 2019. The epidemiology and disease burden were examined at global, regional, and national levels. Additionally, the age and gender patterns were analyzed, followed by an investigation into the primary causes. Lastly, the study studied the correlation between age-standardized rates and the socio-demographic index (SDI).

Results

Over a span of 30 years, both the crude and age-standardized rates of incidence and years lived with disability (YLDs) rates for all genders displayed a slight fluctuating downward trend. The incidence and YLDs rates in males were consistently higher than those in females. The study analyzed both incidence and YLDs rates of the global, regional, and national of traumatic shoulder dislocations from 1990 to 2019, as well as the temporal trends. Among males, the highest incidence rate was observed in young adulthood, while females exhibited the highest incidence rate in old age. This pattern was mirrored in the YLDs rate. Falls were identified as the main cause contributing to the disease burden related to traumatic shoulder dislocations. Moreover, a positive correlation was found between the age-standardized rates and SDI.

Conclusion

The disease burden of traumatic shoulder dislocation has not significantly decreased from 1990 to 2019. The incidence and YLD rates are associated with age, gender, and SDI. A thorough examination of the disease burden contributes to the efficient allocation and utilization of resources, as well as the development of targeted and effective intervention strategies.

Nutrition as the foundation for successful aging: a focus on dietary protein and omega-3 polyunsaturated fatty acids

Skeletal muscle plays a critical role throughout the aging process. People living with sarcopenia, a progressive and generalized loss of skeletal muscle mass and function, often experience diminished quality of life, which can be attributed to a long period of decline and disability. Therefore, it is important to identify modifiable factors that preserve skeletal muscle and promote successful aging (SA). In this review, SA was defined as (1) low cardiometabolic risk, (2) preservation of physical function, and (3) positive state of wellbeing, with nutrition as an integral component. Several studies identify nutrition, specifically high-quality protein (eg, containing all essential amino acids), and long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), as positive regulators of SA. Recently, an additive anabolic effect of protein and n-3 PUFAs has been identified in skeletal muscle of older adults. Evidence further suggests that the additive effect of protein and n-3 PUFAs may project beyond skeletal muscle anabolism and promote SA. The key mechanism(s) behind the enhanced effects of intake of protein and n-3 PUFAs needs to be defined. The first objective of this review is to evaluate skeletal muscle as a driver of cardiometabolic health, physical function, and wellbeing to promote SA. The second objective is to examine observational and interventional evidence of protein and n-3 PUFAs on skeletal muscle to promote SA. The final objective is to propose mechanisms by which combined optimal intake of high-quality protein and n-3 PUFAs likely play a key role in SA. Current evidence suggests that increased intake of protein above the Recommended Dietary Allowance and n-3 PUFAs above the Dietary Guidelines for Americans recommendations for late middle-aged and older adults is required to maintain skeletal muscle mass and to promote SA, potentially through the mechanistical target of rapamycin complex 1 (mTORC1).

Secondary Sarcopenia and Spinal Cord Injury: Clinical Associations and Health Outcomes

Background: Sarcopenia and spinal cord injury (SCI) often coexist, but little is known about the associations. This study aimed to assess the impact of SCI on muscle and bone mass and the correlations between the clinical characteristics of SCI patients and sarcopenia. Methods: A total of 136 patients with SCI admitted to rehabilitation hospital were included in this study. The type and severity of injury (AIS), level of spasticity (MAS), bone mineral density and Appendicular Lean Muscle Mass (ALM) were assessed. Sarcopenia was diagnosed according to EWGSOP2 cut-off points for ALM. Results: Subjects were divided into two groups: Group S-SCI (N = 66, sarcopenia group) and Group NS-SCI (N = 70, without sarcopenia). Mean ALM values in the two groups were 0.49 and 0.65, respectively. A total of 75% of women and 42.9% of men developed sarcopenia. The mean age was 35.8 years in the sarcopenic patients and 41.5 in the non-sarcopenia group. Over 55% of AIS Grades A and B cases, 69.7% of MAS level 0 cases and 51.6% of the patients with osteoporosis had sarcopenia. The mean number of comorbidities was 2.7 in the sarcopenia group. Conclusions: Gender, type of injury, presence of multiple comorbidities and age were directly associated with sarcopenia; meanwhile, surprisingly, spasticity level and the presence of immobilization osteoporosis were not.

Sarcopenia as the Mobility Phenotype of Aging: Clinical Implications

Sarcopenia, which is characterized by an age-related decline in muscle mass and function, poses significant challenges to geriatric care. Its definition has evolved from muscle-specific criteria to include muscle mass, muscle function, and physical performance, recognizing sarcopenia as a physical frailty. Sarcopenia is associated with adverse outcomes, including mortality, falls, fractures, cognitive decline, and admission to long-term care facilities. Neuromechanical factors, protein-energy balance, and muscle protein synthesis-breakdown mechanisms contribute to its pathophysiology. The identification of sarcopenia involves screening tests and a comprehensive assessment of muscle mass, strength, and physical function. Clinical approaches aligned with the principles of comprehensive geriatric assessment prioritize patient-centered care. This assessment aids in identifying issues related to activities of daily living, cognition, mood, nutrition, and social support, alongside other aspects. The general approach to factors underlying muscle loss and functional decline in patients with sarcopenia includes managing chronic diseases and evaluating administered medications, with interventions including exercise and nutrition, as well as evolving pharmacological options. Ongoing research targeting pathways, such as myostatin-activin and exercise mimetics, holds promise for pharmacological interventions. In summary, sarcopenia requires a multifaceted approach, acknowledging its complex etiology and tailoring interventions to individual patient needs.

The Current Landscape of Pharmacotherapies for Sarcopenia

Sarcopenia is a skeletal muscle disorder characterized by progressive and generalized decline in muscle mass and function. Although it is mostly known as an age-related disorder, it can also occur secondary to systemic diseases such as malignancy or organ failure. It has demonstrated a significant relationship with adverse outcomes, e.g., falls, disabilities, and even mortality. Several breakthroughs have been made to find a pharmaceutical therapy for sarcopenia over the years, and some have come up with promising findings. Yet still no drug has been approved for its treatment. The key factor that makes finding an effective pharmacotherapy so challenging is the general paradigm of standalone/single diseases, traditionally adopted in medicine. Today, it is well known that sarcopenia is a complex disorder caused by multiple factors, e.g., imbalance in protein turnover, satellite cell and mitochondrial dysfunction, hormonal changes, low-grade inflammation, senescence, anorexia of aging, and behavioral factors such as low physical activity. Therefore, pharmaceuticals, either alone or combined, that exhibit multiple actions on these factors simultaneously will likely be the drug of choice to manage sarcopenia. Among various drug options explored throughout the years, testosterone still has the most cumulated evidence regarding its effects on muscle health and its safety. A mas receptor agonist, BIO101, stands out as a recent promising pharmaceutical. In addition to the conventional strategies (i.e., nutritional support and physical exercise), therapeutics with multiple targets of action or combination of multiple therapeutics with different targets/modes of action appear to promise greater benefit for the prevention and treatment of sarcopenia.

Effect of sarcopenia on survival in patients after pancreatic surgery: a systematic review and meta-analysis

Background

Numerous studies have reported sarcopenia to be associated with unfavorable outcomes in patients who have undergone pancreatectomy. Therefore, in this meta-analysis, we examined the relationship between sarcopenia and survival after pancreatic surgery.

Methods

PubMed, Embase, and Cochrane Library were searched for studies that examined the association between sarcopenia and survival after pancreatic surgery from the inception of the database until June 1, 2023. Hazard ratio (HR) for overall survival (OS) and/or progression-free survival (PFS) of sarcopenia and pancreatic surgery were extracted from the selected studies and random or fixed-effect models were used to summarize the data according to the heterogeneity. Publication bias was assessed using Egger's linear regression test and a funnel plot.

Results

Sixteen studies met the inclusion criteria. For 13 aggregated univariate and 16 multivariate estimates, sarcopenia was associated with decreased OS (univariate analysis: HR 1.69, 95% CI 1.48-1.93; multivariate analysis: HR 1.69; 95% CI 1.39-2.05, I2 = 77.4%). Furthermore, sarcopenia was significantly associated with poor PFS of pancreatic resection (Change to univariate analysis: HR 1.74, 95% CI 1.47-2.05; multivariate analysis: HR 1.54; 95% CI 1.23-1.93, I2 = 63%).

Conclusion

Sarcopenia may be a significant prognostic factor for a shortened survival following pancreatectomy since it is linked to an elevated risk of mortality. Further studies are required to understand how sarcopenia affects long-term results after pancreatic resection.Systematic review registrationRegistration ID: CRD42023438208 https://www.crd.york.ac.uk/PROSPERO/#recordDetails.

Environmental Enrichment Improves Motor Function and Muscle Transcriptome of Aged Mice

Aging results in the progressive decline of muscle strength. Interventions to maintain muscle strength may mitigate the age-related loss of physical function, thus maximizing health span. The work on environmental enrichment (EE), an experimental paradigm recapitulating aspects of an active lifestyle, has revealed EE-induced metabolic benefits mediated by a brain-fat axis across the lifespan of mice. EE initiated at 18-month of age shows a trend toward an increased mean lifespan. While previous work described EE's influences on the aging dynamics of several central-peripheral processes, its influence on muscle remained understudied. Here, the impact of EE is investigated on motor function, neuromuscular physiology, and the skeletal muscle transcriptome. EE is initiated in 20-month-old mice for a five-month period. EE mice exhibit greater relative lean mass that is associated with improved mobility and hindlimb grip strength. Transcriptomic profiling of muscle tissue reveals an EE-associated enrichment of gene expression within several metabolic pathways related to oxidative phosphorylation and the TCA cycle. Many mitochondrial-related genes-several of which participate in the electron transport chain-are upregulated. Stress-responsive signaling pathways are downregulated because of EE. The results suggest that EE improves motor function-possibly through preservation of mitochondrial function-even late in life.

Association of possible sarcopenia with major chronic diseases and multimorbidity among middle-aged and older adults: Findings from a national cross-sectional study in China

AIM

This study investigated the prevalence of possible sarcopenia (PSA) in a large sample of middle-aged and older adults, and determined the association between PSA, major chronic diseases and the number of chronic diseases.

METHODS

A total of 14 917 adults aged ≥40 years were included in the analysis. The handgrip strength and the five-time chair stand test were used to assess PSA. The participants' major chronic diseases were divided into 14 categories. Four categories were created based on the participants' number of chronic illnesses: 0, 1, 2 and ≥3.

RESULTS

The present study found an overall prevalence of PSA of 23.6% among Chinese middle-aged and older adults aged ≥40 years, with the risk increasing with advancing age. PSA was significantly associated with most categories of chronic diseases and multimorbidity. The closely independent associations were obtained for stroke; emotional, nervous or psychiatric problems; chronic lung disease, asthma, heart disease, hypertension and arthritis or rheumatism. Compared with participants with 0 chronic disease, those with two or more chronic diseases had higher odds for PSA. However, the association between PSA and the number of chronic diseases varied in different sex and age groups.

CONCLUSIONS

The findings suggest that PSA is associated with major chronic diseases among middle-aged and older adults. People with two or more chronic diseases have a greater likelihood of PSA compared with those without chronic diseases, and the association between PSA and the number of chronic diseases largely depended on sex and age. Geriatr Gerontol Int 2023; 23: 925-931.

Use of bioimpedance in prevention of sarcopenia in the elderly

OBJECTIVES

Physiological ageing is associated with major and progressive changes in body composition, particularly in the decline of fat-free mass, which puts older individuals at risk of geriatric syndromes such as sarcopenia and sarcopenic obesity. Bioimpedance analysis noninvasively allows the determination of body composition, thus being able to rapidly assess primary risk factors leading to sarcopenia prediction.

METHODS

We conducted a study of 180 probands, 120 females (66.7%) with a mean age of 76.23 (SD = 9.29) years and 60 males (33.3%) with a mean age of 74.01 (SD = 8.99) years in cooperation with facilities for the elderly and with the inpatient department of the clinics of J.A. Reimann Hospital in Prešov. Body height, body weight, hip circumference, and waist circumference were determined by the anthropometric method, from which the values of the body mass index and waist-to-hip ratio were calculated. Active body mass, total body water, extracellular body water, intracellular body water, cell mass, body mass fat, body fat index, fat-free mass index, impedance at frequencies of 50 kHz, resistance, reactance, and phase angle were determined using the Quadscan 4000 Touch bioimpedance instrument. Appendicular skeletal muscle mass (ASMM) and muscle mass (ASMM/Ht2) were calculated. The data obtained from anthropometric and bioimpedance measurements were processed in MS Excel 2000 and STATISTICA ver. 12. The difference of means in the studied groups was tested by the t-test.

RESULTS

Presarcopenia was diagnosed in 12 (6.66%) probands out of 180 probands, of which were 3 (5%) men and 9 women (7.5%). Phase angle, ASMM and ASMM/Ht2 values were significantly lower (p < 0.001) in men and women with presarcopenia.

CONCLUSION

By introducing bioimpedance measurements into practice, it is possible to obtain results in a non-invasive way revealing possible presarcopenia in the elderly.

The role of estrogen in female skeletal muscle aging: A systematic review

Aging is associated with a loss of skeletal muscle mass and function that negatively impacts the independence and quality of life of older individuals. Females demonstrate a distinct pattern of muscle aging compared to males, potentially due to menopause, when the production of endogenous sex hormones declines. This systematic review aims to investigate the current knowledge about the role of estrogen in female skeletal muscle aging. A systematic search of MEDLINE Complete, Global Health, Embase, PubMed, SPORTDiscus, and CINHAL was conducted. Studies were considered eligible if they compared a state of estrogen deficiency (e.g. postmenopausal females) or supplementation (e.g. estrogen therapy) to normal estrogen conditions (e.g. premenopausal females or no supplementation). Outcome variables of interest included measures of skeletal muscle mass, function, damage/repair, and energy metabolism. Quality assessment was completed with the relevant Johanna Briggs critical appraisal tool, and data were synthesized in a narrative manner. Thirty-two studies were included in the review. Compared to premenopausal women, postmenopausal women had reduced muscle mass and strength, but the effect of menopause on markers of muscle damage and expression of the genes involved in metabolic signaling pathways remains unclear. Some studies suggest a beneficial effect of estrogen therapy on muscle size and strength, but evidence is largely conflicting and inconclusive, potentially due to large variations in the reporting and status of exposure and outcomes. The findings from this review point toward a potential negative effect of estrogen deficiency on aging skeletal muscle, but further mechanistic evidence is needed to clarify its role.

Effects of resistance training and protein supplementation interventions on muscle volume and muscle function: sex differences in humans

PURPOSE

This review aimed to identify differences in the effects of co-intervention with resistance training (RT) and protein supplementation according to sex and provide meaningful information for future research on the development of exercise programs to improve muscle volume and muscle function.

METHODS

PubMed, Science Direct, and Google Scholar were searched to identify clinical and nonclinical studies that assessed the effects of RT in older adults with sarcopenia; these studies were published between 1990 and 2023. Cross-sectional and double-blind studies (randomized controlled trials, RCTs) were examined in this review.

RESULTS

The effects of parallel intervention with RT and protein supplementation on muscle volume and physical function were found to differ according to sex. Both males and females had improvements in muscle strength, muscle mass, and physical function after RT and protein supplementation; however, many studies found a greater increase in muscle volume and function in males than in females. Such difference may be due to differences in physiological characteristics between males and females.

CONCLUSION

Based on the findings of this review, the effects of combined intervention with RT and protein supplementation on muscle strength, muscle mass, and physical function to differ according to sex. Owing to these sex differences in the response and physiological characteristics caused by the parallel intervention of RT and protein supplementation, such differences must be considered to maximize the effects of RT and protein supplementation.

Age Is Just a Number: Progress and Obstacles in the Discovery of New Candidate Drugs for Sarcopenia

Sarcopenia is a disease characterized by the progressive loss of skeletal muscle mass and function that occurs with aging. The progression of sarcopenia is correlated with the onset of physical disability, the inability to live independently, and increased mortality. Due to global increases in lifespan and demographic aging in developed countries, sarcopenia has become a major socioeconomic burden. Clinical therapies for sarcopenia are based on physical therapy and nutritional support, although these may suffer from low adherence and variable outcomes. There are currently no clinically approved drugs for sarcopenia. Consequently, there is a large amount of pre-clinical research focusing on discovering new candidate drugs and novel targets. In this review, recent progress in this research will be discussed, along with the challenges that may preclude successful translational research in the clinic. The types of drugs examined include mitochondria-targeting compounds, anti-diabetes agents, small molecules that target non-coding RNAs, protein therapeutics, natural products, and repositioning candidates. In light of the large number of drugs and targets being reported, it can be envisioned that clinically approved pharmaceuticals to prevent the progression or even mitigate sarcopenia may be within reach.

Application of machine learning and its effects on the development of a nursing guidance mobile app for sarcopenia

BACKGROUND

Aging leads to changes in the body system, such as sarcopenia. This can result in several health issues, particularly physical and mobility dysfunction. Asian people typically have little awareness of sarcopenia. Thus, this study incorporated nursing instruction into the mobile application design to allow users to easily learn about sarcopenia.

OBJECTIVE

This study evaluated a model for predicting high-risk populations for sarcopenia in home settings. We further developed a sarcopenia nursing guidance mobile application and assessed the effectiveness of this application in influencing sarcopenia-related knowledge and self-care awareness among participants.

METHODS

Using a one-group pretest-posttest design, data were collected from 120 participants at a teaching hospital in northern Taiwan. This study used an artificial intelligence algorithm to evaluate a model for predicting high-risk populations for sarcopenia. We developed and assessed the sarcopenia nursing guidance mobile application using a questionnaire based on the Mobile Application Rating Scale.

RESULTS

The application developed in this study enhanced participants' sarcopenia-related knowledge and awareness regarding self-care. After the three-month intervention, the knowledge and awareness was effectively increase, total score was from 4.15 ± 2.35 to 6.65 ± 0.85 and were significant for all questionnaire items (p values < 0.05). On average, 96.1% of the participants were satisfied with the mobile app. The artificial intelligence algorithm positively evaluated the home-use model for predicting high-risk sarcopenia groups.

CONCLUSIONS

The mobile application of the sarcopenia nursing guidance for public use in home settings may help alleviate sarcopenia symptoms and reduce complications by enhancing individuals' self-care awareness and ability.

TRIAL REGISTRATION

NCT05363033, registered on 02/05/2022.

Evaluation of sarcopenia in patients receiving intravesical Bacillus Calmette-Guérin for non-muscle invasive bladder cancer

BACKGROUND

Sarcopenia is associated with adverse outcomes for patients with muscle invasive bladder cancer (MIBC), but less is known about its impact in the setting of non-muscle invasive bladder cancer (NMIBC). Sarcopenia, skeletal muscle density, and adipose tissue area have been studied as markers of malnutrition and can be determined radiographically. The purpose of this study is to characterize the prevalence of sarcopenia in patients with NMIBC receiving intravesical Bacillus Calmette-Guérin (BCG).

METHODS

Following institutional review board approval, patients with NMIBC having received intravesical BCG were identified using institutional pharmacy records. Patients having undergone computed tomography (CT) of the abdomen and pelvis within 90 days of treatment were included in the analysis. Using sliceOmatic 5.0 software, skeletal muscle area (cm2) was measured at the L3 level to calculate skeletal muscle index (SMI), a marker of sarcopenia. Subcutaneous, visceral, and intramuscular adipose tissue areas in addition to skeletal muscle density were also measured. Frailty was evaluated as a secondary aim using the 5-Item Modified Frailty Index (mFI-5). Using predefined cutoffs, the prevalence of sarcopenia was determined. Descriptive statistics were used to characterize frailty and secondary body composition characteristics. Statistical analysis was performed to evaluate the impact of sarcopenia on recurrence rate and progression.

RESULTS

A total of 308 patients having received BCG between 2015 and 2020 were identified, of which 90 met criteria for analysis. Nearly all (94%) patients completed at least 5 out of 6 BCG induction instillations. Median body mass index (kg/m2) was 27.64 (IQR 24.9, 30.5) for females and 27.7 (IQR 24.9, 30.66) for males. Median SMI (cm2/m2) was 49.44 (IQR 39.39, 55.17) for females and 49.58 (IQR 40.25, 55.58) for males. A majority (61%) of patients were found to be sarcopenic. High-risk frailty was identified 36% of patients. There was no association between sarcopenia and recurrence rate or progression.

CONCLUSIONS

Sarcopenia and frailty are highly prevalent amongst patients with NMIBC. A diagnosis of NMIBC represents a window of opportunity to identify and intervene on modifiable risk factors such as sarcopenia and frailty, which are associated with adverse outcomes in more advanced disease states.

Recent Advances in Nutraceuticals for the Treatment of Sarcopenic Obesity

Sarcopenic obesity, low muscle mass, and high body fat are growing health concerns in the aging population. This review highlights the need for standardized criteria and explores nutraceuticals as potential therapeutic agents. Sarcopenic obesity is associated with insulin resistance, inflammation, hormonal changes, and reduced physical activity. These factors lead to impaired muscle activity, intramuscular fat accumulation, and reduced protein synthesis, resulting in muscle catabolism and increased fat mass. Myostatin and irisin are myokines that regulate muscle synthesis and energy expenditure, respectively. Nutritional supplementation with vitamin D and calcium is recommended for increasing muscle mass and reducing body fat content. Testosterone therapy decreases fat mass and improves muscle strength. Vitamin K, specifically menaquinone-4 (MK-4), improves mitochondrial function and reduces muscle damage. Irisin is a hormone secreted during exercise that enhances oxidative metabolism, prevents insulin resistance and obesity, and improves bone quality. Low-glycemic-index diets and green cardamom are potential methods for managing sarcopenic obesity. In conclusion, along with exercise and dietary support, nutraceuticals, such as vitamin D, calcium, vitamin K, and natural agonists of irisin or testosterone, can serve as promising future therapeutic alternatives.

Association of Sarcopenia With Mortality in Patients With Chronic Limb-Threatening Ischemia Undergoing Endovascular Revascularization

INTRODUCTION

Chronic limb-threatening ischemia (CLTI) is the most severe form of peripheral artery disease and leads high mortality. Sarcopenia, characterized by the loss of muscle mass or poor muscle quality, is associated with adverse clinical outcomes. This study aimed to investigate the association between sarcopenia and the long-term outcomes in patients with CLTI after endovascular revascularization.

METHODS

We retrospectively reviewed the medical records of all patients with CLTI who underwent endovascular revascularization between January 2015, and December 2021. The skeletal muscle area was calculated at the third lumbar vertebra from computed tomography images using the manual trace method and normalized to patient height. Sarcopenia was defined as a third lumbar skeletal muscle index of <40.8 cm2/m2 in males and <34.9 cm2/m2 in females. The Kaplan-Meier and Cox proportional hazards regression analyses were used for survival analysis and to evaluate the association between sarcopenia and mortality.

RESULTS

A total of 137 patients (90 men; mean age 71.7 ± 9.6 y) were enrolled for the study, of whom 56 (40.8%) had sarcopenia. The 3-year overall survival rate in patients with CLTI who underwent endovascular revascularization was 71.2%. The sarcopenic group had a significantly worse 3-year overall survival rate than the nonsarcopenic group (55.3% versus 78.6%, P = 0.001). Multivariate Cox proportional hazard regression analyses revealed that sarcopenia (hazard ratio, 2.262; 95% confidence interval, 1.132-4.518; P = 0.021) and dialysis (hazard ratio, 3.021; 95% confidence interval, 1.337-6.823; P = 0.008) were independently associated with increased risk of all-cause mortality, whereas technical success had significantly opposing correlation with mortality. (hazard ratio, 0.400, 95% confidence interval, 0.194-0.826, P = 0.013).

CONCLUSIONS

Sarcopenia can be highly prevalent in patients with CLTI who undergo endovascular revascularization, and is independently associated with long-term mortality. These results may help risk stratification to assist in personalized assessment and clinical decision-making.

A narrative review on the impact of sarcopenic obesity and its psychological consequence in quality of life

BACKGROUND AND AIM

Sarcopenia is a multifactorial metabolic-mediated complication that affects most of the geriatric population physically and mentally. In this study, we intended to study the association between sarcopenia and psychologically related symptoms. Primary objective of the study is to explore the interplay between sarcopenic obesity, psychological consequences and Quality of life in the affected population. The secondary objective is to discuss the diagnostic, treatment approaches and also the role of clinical pharmacist.

METHOD

The psychology-related complication and sarcopenia association was enumerated in this study based on previous clinical research findings.

RESULT

The clinical evidence shows a strong correlation between sarcopenia and Mental health and its health consequences and reflection on the quality of life.

CONCLUSION

Sarcopenia induced mental disturbance has been affirmed in many studies. We believe effective right pharmacological therapy and non-pharmacological therapies with respective lifestyle modification advice could be potential vital factors that can reduce further complications in geriatric populations.

MAFLD might be better in identifying subjects with sarcopenia or cardiovascular risk than NAFLD: A nationwide study

BACKGROUND AND AIM

Clinical features of non-alcoholic fatty liver disease (NAFLD), but not fulfilling the diagnostic criteria of metabolic dysfunction-associated fatty liver disease (MAFLD), remain unclear. We investigated the risk of sarcopenia and cardiovascular disease (CVD) in MAFLD and non-metabolic risk (MR) NAFLD.

METHODS

Subjects were selected from the Korean National Health and Nutrition Examination Surveys 2008-2011. Liver steatosis was assessed using fatty liver index. Significant liver fibrosis was defined using fibrosis-4 index, categorized by age cut-offs. Sarcopenia was defined as the lowest quintile sarcopenia index. Atherosclerotic CVD (ASCVD) risk score > 10% was defined as high probability.

RESULTS

A total of 7248 subjects had fatty liver (137 with non-MR NAFLD, 1752 with MAFLD/non-NAFLD, and 5359 with overlapping MAFLD and NAFLD). In non-MR NAFLD group 28 (20.4%) had significant fibrosis. The risk of sarcopenia (adjusted odds ratio [aOR] = 2.71, 95% confidence index [CI] = 1.27-5.78) and high probability of ASCVD (aOR = 2.79, 95% CI = 1.23-6.35) was significantly higher in MAFLD/non-NAFLD group than in non-MR NAFLD group (all P < 0.05). The risk of sarcopenia and high probability of ASCVD was similar between subjects with and without significant fibrosis in non-MR NAFLD group (all P > 0.05). However, the risk was significantly higher in MAFLD group than in non-MR NAFLD group (aOR = 3.38 for sarcopenia and 3.73 for ASCVD; all P < 0.05).

CONCLUSIONS

The risks of sarcopenia and CVD were significantly higher in MAFLD group but did not differ according to fibrotic burden in non-MR NAFLD group. The MAFLD criteria might be better for identifying high-risk fatty liver disease than the NAFLD criteria.

Relationship between DNA methylation changes and skeletal muscle mass

BACKGROUND

Sarcopenia is a disease diagnosed in the elderly. In patients with sarcopenia, the muscle mass decreases every year. The occurrence of sarcopenia is greatly affected by extrinsic factors such as eating habits, exercise, and lifestyle. The present study aimed to determine the relationship between muscle mass traits and genes affected by epigenetic factors with three different adjustment methods using Korean Genome and Epidemiology Study (KOGES) data.

RESULTS

We conducted a demographic study and DNA methylation profiling by three studies according to the muscle mass index (MMI) adjustment methods: appendicular skeletal muscle mass divided by body weight (MMI1); appendicular skeletal muscle mass divided by square of height (MMI2); appendicular skeletal muscle mass divided by BMI (MMI3). We analyzed differentially methylated regions (DMRs) for each group. We then restricted our subjects to be top 30% (T30) and bottom 30% (B30) based on each MMI adjustment method. Additionally, we performed enrichment analysis using PathfindR to evaluate the relationship between identified DMRs and sarcopenia. A total of 895 subjects were included in the demographic study. The values of BMI, waist, and hip showed a significant difference in all three groups. Among 446 participants, 44 subjects whose DNA methylation profiles were investigated were included for DNA methylation analysis. The results of enrichment analysis showed differences between groups. In the women group through MMI1 method, only the glutamatergic synapse pathway showed a significant result. In the men group through MMI2 method, the adherens junction pathway was the most significant. Women group through MMI2 method showed similar results, having an enriched Rap1 signaling pathway. In men group through MMI3 method, the Fc epsilon RI signaling pathway was the most enriched. Particularly, the notch signaling pathway was significantly enriched in women group through MMI3 method.

CONCLUSION

This study presents results about which factor should be concerned first in muscle mass index (MMI) adjustment. The present study suggested that GAB2 and JPH3 in MMI1 method, HLA-DQB1 and TBCD in MMI2 method, GAB2, NDUFB4 and ISPD in MMI3 method are potential genes that can have an impact on muscle mass. It could enable future epigenetic studies of genes based on annotation results. The present study is a nationwide study in Korea with the largest size up to date that compares adjustment indices for MMI in epigenetic research.

GABA Prevents Age-Related Sarcopenic Obesity in Mice with High-Fat-Diet-Induced Obesity

Sarcopenic obesity is characterized by concurrent obesity and muscle wasting (sarcopenia) and is common in the elderly. Sarcopenic obesity has steadily increased as the aging population has grown and is an increasing public health burden. Both obesity and sarcopenia independently increase health risks of the elderly, but sarcopenic obesity has a greater effect on metabolic disease than either obesity or sarcopenia alone. The metabolic mechanisms of obesity and sarcopenia are strongly interconnected, and obesity and sarcopenia form a vicious cycle, with each pathology exacerbating the other. The pathogenesis of sarcopenic obesity is more complex than either disease alone and remains incompletely understood, underscoring the significant unmet clinical need for effective sarcopenic obesity treatments. We aimed to determine the efficacy and underlying regulatory mechanisms of Gamma-aminobutyric acid (GABA) in sarcopenic obesity in high-fat-diet-fed obese aged mice and alterations in related mechanisms to determine the potential of GABA as a therapeutic modality for sarcopenic obesity. In this study, we used young (3 months) and aged (20 months) mice to evaluate age-related sarcopenic obesity. The daily administration of GABA for 8 weeks resulted in decreased fat mass and increased muscle mass and strength in aged mice. GABA also enhanced energy expenditure in both adipose tissue and skeletal muscle. In addition, GABA promoted muscle synthesis and decreased muscle degradation by activating the phosphatidylinositol-3-kinase (PI3K)/Akt pathway. These findings demonstrate that GABA has potential uses in preventing age-related sarcopenic obesity and related metabolic diseases.

Handgrip strength is positively associated with successful aging in older adults: A national cross-sectional study in China

OBJECTIVES

Muscle strength gradually decreases with advancing age. This study aimed to explore the relationship between handgrip strength and successful aging and its specific dimensions in older adults using a nationally representative sample.

METHODS

A total of 5269 adults aged 60 and older were included in this study. Handgrip strength was measured using a dynamometer and was organized into quartiles by sex. Successful aging was defined by Rowe and Kahn's conceptual model including the following five dimensions: (a) no major diseases; (b) freedom from disability; (c) high cognitive function; (d) good psychological status; and (e) active social engagement in life. Logistic regression models were used to examine the association between handgrip strength and successful aging and its specific dimensions.

RESULTS

The prevalence of successful aging was found to be 35.1 % in Chinese older adults. Compared to older adults with handgrip strength in the first quartile, those with handgrip strength in the second quartile, third quartile, and fourth quartile had a higher probability of successful aging (adjusted odds ratio (OR): 1.40 (95 % CI: 1.16, 1.69) to 2.06 (95 % CI: 1.70, 2.50)). We further found that the association between handgrip strength and successful aging was related to different ages.

CONCLUSION

This study suggested that there is a close association between handgrip strength and successful aging. Older adults who have greater handgrip strength can successfully deal with the challenges of aging. For older people, keeping a high level of muscle strength in late life may be helpful to the constant successful aging.

Review article: Putting some muscle into sarcopenia-the pathogenesis, assessment and clinical impact of muscle loss in patients with inflammatory bowel disease

BACKGROUND

Sarcopenia, a loss of skeletal muscle mass or function, affects up to 50% of patients with inflammatory bowel disease (IBD) and is associated with poor clinical outcomes including increased hospitalizations, need for surgery and post-operative complications. Despite the high prevalence and clinical significance of sarcopenia in patients with IBD, few patients undergo routine muscle evaluation.

AIM

The goal of this study was to review the mechanisms of sarcopenia in patients with IBD and understand novel modalities to assess and treat impaired muscle mass or function.

METHODS

Pubmed and Cochrane databases were searched including articles published up to February 2023 utilizing the following keywords: "inflammatory bowel disease", "IBD", "Crohn's disease", "ulcerative colitis", "sarcopenia", "myosteatosis", "muscle health", and "frailty".

RESULTS

The pathogenesis of sarcopenia in IBD is not well defined, however, there is evidence supporting the role of malabsorption, reduced protein intake, chronic inflammation, dysbiosis, decreased physical activity, medication effects and hormone signaling from visceral adiposity. Traditional sarcopenia assessment techniques include direct measurements on cross sectional imaging. However, given the time, cost and radiation exposure associated with cross sectional imaging, new bedside tools are now available to estimate muscle mass, including assessment of grip strength, mid upper arm circumference and body composition utilizing bioelectrical impedance analysis. In addition, novel biomarkers for assessing muscle mass and techniques utilizing point of care ultrasound have been proposed to make sarcopenia evaluation more streamlined in the IBD clinic.

CONCLUSION

Sarcopenia is associated with poor clinical outcomes independent of IBD activity and therefore muscle health should be assessed in all IBD patients at routine intervals. Future studies to better our understanding of the pathophysiology as well as most effective management of sarcopenia in IBD will help guide clinical care and reduce disease related complications.

Dental care and oral conditions are associated with the prevalence of sarcopenia in people with type 2 diabetes: a cross-sectional study

BACKGROUND

Insulin resistance, which is closely associated with type 2 diabetes mellitus (T2DM), is a cause of sarcopenia and people with T2DM have a high risk of sarcopenia. Keeping good oral condition by dental care is important for people with T2DM. Keeping good oral condition by dental care is important for people with T2DM. This study has investigated the association between dental care or oral conditions and sarcopenia in people with T2DM.

METHODS

Dental care and oral conditions were evaluated based on a self-reported questionnaire. Individuals with both low handgrip strength and low skeletal muscle mass index were diagnosed with sarcopenia.

RESULTS

Among 266 people with T2DM, the proportions of sarcopenia, not having a family dentist, not having a toothbrushing behavior, poor chewing ability, and use of complete dentures were 18.0%, 30.5%, 33.1%, 25.2%, and 14.3%, respectively. The proportions of sarcopenia in people not having a family dentist (27.2% vs. 14.1%, p = 0.017), those with poor chewing ability (26.9% vs. 15.1%, p = 0.047), and use of complete dentures (36.8% vs. 14.9%, p = 0.002) were higher than those in people without. The proportion of sarcopenia in people without toothbrushing behavior tended to be higher than that in people with toothbrushing behavior (25.0% vs. 14.6%, p = 0.057). Not having a family dentist (adjusted odds ratio [OR] 2.48 [95% confidence interval (CI): 1.21-5.09], p = 0.013), poor chewing ability (adjusted OR 2.12 [95% CI: 1.01-4.46], p = 0.048), and use of complete dentures (adjusted OR 2.38 [95% CI: 1.01-5.99], p = 0.046) were related to the prevalence of sarcopenia.

CONCLUSIONS

This study revealed that dental care and oral conditions were associated with the prevalence of sarcopenia.

Identification and Characterization of Peptides from Bovine Collagen Hydrolysates that Promote Myogenic Cell Proliferation

In this study, bovine collagen hydrolysate was purified via a series of chromatograms, and the peptides with the highest activity for promoting myoblast proliferation were identified by LC-MS-MS. It was demonstrated that the peptide GDAGPPGPAGPAGPPGPIG (hydroxylation) could promote C2C12 proliferation (+18.5% ± 0.04, P < 0.05). The certain peptide was capable of regulating the myogenic cell cycle and inhibiting myogenic cell apoptosis. By combining molecular docking, quantitative real-time PCR, and metabonomics, we suggested that the peptide GDAGPPGPAGPAGPPGPIG (hydroxylation) might bind to FGFR1 and affect the expression of genes downstream of FGFR1 and influence protein synthesis to promote myoblast proliferation. The above results showed that the peptides isolated in this study have the potential to alleviate sarcopenia in the elderly.

Six-Month Synbio® Administration Affects Nutritional and Inflammatory Parameters of Older Adults Included in the PROBIOSENIOR Project

The physiological changes associated with ageing contribute to the incidence of diseases, morbidity, and mortality. For modern society, it is essential to find solutions to improve elderly people's health and quality of life. Among promising strategies, the PROBIOSENIOR project proposed a daily six-month supplementation with new probiotic functional foods and nutraceuticals. The aim of this work was to evaluate the modulating effects of the probiotic diet on inflammatory markers and nutritional status. Ninety-seven elderly volunteers were randomly assigned to either a placebo-diet group or a probiotic-diet group (SYNBIO^®). Faeces, urine, and blood samples were collected before and after the supplementation to determine serum cytokines, biogenic amines, and inflammation markers. Comparing the results obtained before and after the intervention, probiotic supplementations significantly decreased the TNF-α circulating levels and significantly increased those of IGF-1. Biogenic-amine levels showed high variability, with significant variation only for histamine that decreased after the probiotic supplementation. The supplementation influenced the serum concentration of some crucial cytokines (IL-6, IL-8, and MIP-1α) that significantly decreased in the probiotic group. In addition, the Mini Nutritional Assessment questionnaire revealed that the probiotic-supplemented group had a significant improvement in nutritional status. In conclusion, the PROBIOSENIOR project demonstrated how SYNBIO^® supplementation may positively influence some nutritional and inflammatory parameters in the elderly.

COVID-19 in Older Patients: Assessment of Post-COVID-19 Sarcopenia

(1) Background: Acute COVID-19 infections produce alterations in the skeletal muscle, leading to acute sarcopenia, but the medium- and long-term consequences are still unknown. The aim of this study was to evaluate: (1) body composition; (2) muscle strength and the prevalence of sarcopenia; and (3) the relationship between muscle strength with symptomatic and functional evolution in older patients affected by/recovered from COVID-19; (2) Methods: A prospective, longitudinal study of patients aged ≥65 years who had suffered from COVID-19 infection between 1 March and 31 May 2020, as confirmed by PCR or subsequent seroconversion. Persistent symptoms, as well as anthropometric, clinical, and analytical characteristics, were analyzed at 3 and 12 months after infection. The degree of sarcopenia was determined by dynamometry and with SARC-F; (3) Results: 106 participants, aged 76.8 ± 7 years, were included. At 3 months postinfection, a high percentage of sarcopenic patients was found, especially among women and in those with hospitalization. At 12 months postinfection, this percentage had decreased, coinciding with a functional and symptomatic recovery, and the normalization of inflammatory parameters, especially interleukin-6 (4.7 ± 11.6 pg/mL vs. 1.5 ± 2.4 pg/mL, p < 0.05). The improvement in muscle strength was accompanied by significant weight gain (71.9 ± 12.1 kg vs. 74.7 ± 12.7 kg, p < 0.001), but not by an increase in lean mass (49.6 ± 10 vs. 49.9 ± 10, p 0.29); (4) Conclusions: Older COVID-19 survivors presented a functional, clinical, and muscular recovery 12 months postinfection. Even so, it is necessary to carry out comprehensive follow-ups and assessments that include aspects of nutrition and physical activity.

Body composition parameters, immunonutritional indexes, and surgical outcome of pancreatic cancer patients resected after neoadjuvant therapy: A retrospective, multicenter analysis

Background and aims

Body composition parameters and immunonutritional indexes provide useful information on the nutritional and inflammatory status of patients. We sought to investigate whether they predict the postoperative outcome in patients with pancreatic cancer (PC) who received neoadjuvant therapy (NAT) and then pancreaticoduodenectomy.

Methods

Data from locally advanced PC patients who underwent NAT followed by pancreaticoduodenectomy between January 2012 and December 2019 in four high-volume institutions were collected retrospectively. Only patients with two available CT scans (before and after NAT) and immunonutritional indexes (before surgery) available were included. Body composition was assessed and immunonutritional indexes collected were: VAT, SAT, SMI, SMA, PLR, NLR, LMR, and PNI. The postoperative outcomes evaluated were overall morbidity (any complication occurring), major complications (Clavien-Dindo ≥ 3), and length of stay.

Results

One hundred twenty-one patients met the inclusion criteria and constituted the study population. The median age at the diagnosis was 64 years (IQR16), and the median BMI was 24 kg/m² (IQR 4.1). The median time between the two CT-scan examined was 188 days (IQR 48). Skeletal muscle index (SMI) decreased after NAT, with a median delta of -7.8 cm²/m² (p < 0.05). Major complications occurred more frequently in patients with a lower pre-NAT SMI (p = 0.035) and in those who gained in subcutaneous adipose tissue (SAT) compartment during NAT (p = 0.043). Patients with a gain in SMI experienced fewer major postoperative complications (p = 0.002). The presence of Low muscle mass after NAT was associated with a longer hospital stay [Beta 5.1, 95%CI (1.5, 8.7), p = 0.006]. An increase in SMI from 35 to 40 cm²/m² was a protective factor with respect to overall postoperative complications [OR 0.43, 95% (CI 0.21, 0.86), p < 0.001]. None of the immunonutritional indexes investigated predicted the postoperative outcome.

Conclusion

Body composition changes during NAT are associated with surgical outcome in PC patients who receive pancreaticoduodenectomy after NAT. An increase in SMI during NAT should be favored to ameliorate the postoperative outcome. Immunonutritional indexes did not show to be capable of predicting the surgical outcome.

Elevated intramuscular adipose tissue content with a high Ishak fibrosis stage (>3) had a negative effect on liver regeneration in cirrhotic patients undergoing portal vein embolization

This study investigated the relationship between body composition parameters and changes in future liver remnant volume (FLRV) in hepatocellular carcinoma (HCC) patients undergoing portal vein embolization (PVE) in preparation for right hepatectomy. This retrospective study enrolled 21 patients between May 2013 and October 2020. Body composition parameters, including skeletal muscle attenuation (SMA), skeletal muscle mass index (SMI), intramuscular adipose tissue content (IMAC), and visceral-to-subcutaneous adipose tissue area ratio (VSR), were measured by computed tomography (CT) prior to PVE. Liver volumetry was measured before and at least 5 weeks after PVE. The mean interval between two CT volumetries was 9.1 ± 4.9 weeks, the mean value of increase in FLRV (ΔFLRV) was 236.0 ± 118.3 cm³ , the ratio of increased FLRV (ΔFLRV%) was 55.7 ± 29.4%, and the rate of increased FLRV was 31.0 ± 18.8 (cm³ /week). Subjects with high IMAC showed significantly lower (p = 0.044) ΔFLRV% than those with normal IMAC. Furthermore, ΔFLRV% was linearly reduced (p for trend = 0.043) among those with low Ishak fibrosis stage (<3) + normal IMAC (76.1 ± 36.8%), those with low Ishak fibrosis stage (<3) + high IMAC or high Ishak fibrosis stage (>3) + normal IMAC (54.0 ± 24.1%), and those with high Ishak fibrosis stage (>3) + low IMAC (28.7 ± 1.6%) (p for trend = 0.043). Our data indicated that high IMAC with a high Ishak fibrosis stage (>3) had a significant negative effect on ΔFLRV%.

Hypoglycemic drug liraglutide alleviates low muscle mass by inhibiting the expression of MuRF1 and MAFbx in diabetic muscle atrophy

BACKGROUND

Low muscle mass, that is, muscular atrophy, is an independent risk factor for type 2 diabetes mellitus (T2DM). Few studies investigated whether hypoglycemic drugs can alleviate low muscle mass and related mechanisms.

METHODS

This study recruited 51 type 2 diabetes mellitus (T2DM) patients, who were divided into two groups based on skeletal muscle index (SMI) evaluated by Dual-energy X-ray absorptiometry (DXA): the experiment group (n = 25, SMI < 7 kg/m 2 ) and the control group (n = 26, SMI≥7 kg/m 2 ). GLP-1 levels were measured by ELISA. In vitro, 10 KK-A y mice (11- to 12-week-old) were assigned into two groups: liraglutide group (n = 5) and saline group (n = 5). Real-time PCR and Western blot were used to determine the expression levels of muscle specific ubiquitin protease E3, MuRF1, and MAFbx.

RESULTS

T2DM patients with a higher SMI had significantly higher GLP-1 levels (t = 3.77, p < 0.001). SMI were positively associated with GLP-1 levels (β = 0.435, p = 0.001) and inversely associated with age (β = 0.299, p = 0.015). The incidence of low muscle mass at below the second quartiles was 10.55 times that of above the second quartiles (odds ratio = 10.556, p < 0.001). Liraglutide-treatment mice showed significant decrease in food intake, final body weight, fasting blood glucose, and significant increase in skeletal muscle mass, which coincided with the significant decrease in the expression levels of ubiquitin protease E3 MuRF1 and MAFbx. In vitro studies showed that liraglutide promoted myogenic differentiation and attenuated dexamethasone (DEX)-induced myotube atrophy. Ectopic expression of MuRF1 and MAFbx antagonized the beneficial effects of liraglutide on DEX-induced myotube atrophy.

CONCLUSION

T2DM patients have muscular atrophy, and liraglutide alleviates muscular atrophy at least in part by inhibiting the expression of MuRF1 and MAFbx.

Screening efficacy of PhA and MNA-SF in different stages of sarcopenia in the older adults in community

OBJECTIVE

To compare the screening ability of the phase Angle (PhA) and the Short-Form Mini Nutritional Assessment (MNA-SF) alone and combined detection in the different stages of sarcopenia among the older adults in the community.

METHODS

The older adults aged 65 and above were enlisted during community outpatient service and their nutritional status was evaluated by MNA-SF scale. PhA was measured by bioelectrical impedance analysis (BIA). AWGS2019 and EWGSOP2010 were used to define the different stages of sarcopenia. We measured skeletal mass index (SMI) and grip strength with BIA and electronic grip apparatus and measured body function with 6-m pace, SPPB test, and standing test.

RESULTS

The AUC of PhA in the screening of possible sarcopenia was 0.640, the sensitivity was 58.49%, the specificity was 66.67%, and the cut-off value was 4.5. The AUC of the combined PhA and MNA-SF for possible sarcopenia was 0.642, the sensitivity was 57.55%, and the specificity was 70.00%. The AUC of MNA-SF for the screening of pre-sarcopenia was 0.805, the sensitivity was 66.67%, the specificity was 85.83%, and the cut-off value was 12. The AUC of the combined PhA and MNA-SF was 0.826, the sensitivity was 75.00%, and the specificity was 85.00%. The AUC of PhA in the screening of sarcopenia (common type) was 0.808, the sensitivity was 82.35%, the specificity was 73.33%, the cut-off value was 4.4. The AUC of the combined PhA and MNA-SF for sarcopenia (common type) was 0.835, the sensitivity was 76.47% and the specificity was 81.67%. The AUC of PhA and for the screening of severe sarcopenia was 0.935, the sensitivity was 93.33%, the specificity was 92.50%, and the cut-off value was 4.1. The AUC of the combined PhA and MNA-SF was 0.943, the sensitivity was 86.67%, and the specificity was 93.33%.

CONCLUSION

The screening ability of PhA alone or in combination was higher than that of MNA-SF in the screening of possible sarcopenia. The screening ability of the combined detection was higher than that of PhA alone in the screening of pre-sarcopenia. The combination of PhA and MNA-SF or PhA alone all performed better value in the screening of sarcopenia (common type). Compared to MNA-SF, the PhA performed better in the screening of severe sarcopenia, which provided references for identifying patients with different stages of sarcopenia in the community.

Demographic and Genome Wide Association Analyses According to Muscle Mass Using Data of the Korean Genome and Epidemiology Study

BACKGROUND

Sarcopenia is commonly found in the elderly due to a decline in muscle mass. Many researchers have performed genome-wide association studies (GWAS) to find genetic risk factors of sarcopenia. Although many studies have discovered sarcopenia associated single nucleotide polymorphisms (SNPs), most of them are studies targeting Caucasians. The purpose of this study was to evaluate genetic correlation according to muscle mass in middle aged Koreans using data of the Korean Genome and Epidemiology Study (KOGES), a large population-based genomic cohort study.

METHODS

Baseline participants were 10,030 subjects aged 40 to 69 years who were from Ansan or Anseong in Gyeonggi-do, South Korea. Among them, 9,351 subjects with laboratory data available were included in this study. To identify sarcopenia associated variants, those in the top 30% and bottom 30% of muscle mass index (MMI) were compared. A total of 7,452 people with an MMI of 30-70% were excluded. A total of 1,004 people were also excluded due to missing data. Finally, 895 people were selected for this study. The Korea Biobank Array generated 500,568 SNPs for this dataset.

RESULTS

When subjects were divided into top 30% and bottom 30% of MMI, the top 30% had 169 men and 308 women and the bottom 30% had 220 men and 198 women. In men, age, body mass index (BMI), waist and hip were significantly (P < 0.005) different between top 30% and bottom 30% MMI groups. In women, age, BMI, waist, hip, and hypertension history were significantly different between the two MMI groups. There were 13 significant SNPs in men and 14 significant SNPs in women. Genes associated with variants in men based on the single-nucleotide polymorphism database (dbSNP) were LRP1B containing rs11679458 and RGS6 containing rs11848300. A gene associated with variants in women was Pi4K2A, which contained rs1189312 as a variant. In addition, rs11189312 was associated with expression quantitative trait loci (eQTL) of ZFYVE27 in skeletal muscles and other SNPs of ZFYVE27 (rs10882883, rs17108378, rs35077384) known to be associated with spastic paraplegia. The eQTL analysis revealed that rs11189312 was a variant associated with SNPs of ZFYVE27.

CONCLUSIONS

In the demographic study, significant results were found in BMI, waist, hip, history of hyperlipidemia, and sedentary life status in male group, and significant results were found in BMI, waist, hip, and hypertension history in female group. Variant rs11189312 was found to be a novel variant affecting ZFYVE27 expressed in skeletal muscles, suggesting that rs11189312 might be related to sarcopenia as a novel discovery of this study. Further study is needed to determine the association between sarcopenia and ZFYVE27 known to be associated with spastic paraplegia.

The methods of prophylaxis of the pancreatic fistula occurrence after pancreato–duodenectomy

Objective. To elaborate the measures system, which permit to reduce the occurrence of pancreatic fistula and other severe complications after performance of pancreato–duodenectomy. Materials and methods. There were analyzed the results of treatment of 327 patients, in whom pancreato–duodenectomy was performed. In accordance to the scheme proposed, using the elaborated scale of risk for the postoperative pancreatic fistula occurrence with estimation of sarcopenia presence and application of certain prophylactic measures 98 patients were operated in period from November 2018 to December 2020 yr. (the main group). Into the control group 229 patients were included, operated on in the clinic from January 2015 to October 2018 yr. without estimation of risk for the pancreatic fistula occurrence and presence of sarcopenia. The method of pancreato–jejunoanastomosis formation was selected by operating surgeon. Results. Postoperative complications have occurred in 94 (41.0%) patients of the control group and in 28 (28.6%) patients of the main group (c 2 = 4.56, p=0.03). Clinically significant postoperative pancreatic fistula of B Degree have occurred in 9 (9.2%) patients of the main group, what was statistically significantly lower, than in the control group, in which postoperative pancreatic fistula of B or C Degree have occurred in 64 (27.9%) patients (c 2 = 11.6, p=0.0007). Lethality was 2.2% in the control group and 1.02% – in the main one. Conclusion. Introduction of the measures system elaborated have permitted to lower the postoperative pancreatic fistula rate statistically significantly from 27.9 to 9.2%, and of other postoperative complications – from 41.0 to 28.6% and lethality from 2.2 to 1.02%.

Single nuclei profiling identifies cell specific markers of skeletal muscle aging, frailty, and senescence

Aging is accompanied by a loss of muscle mass and function, termed sarcopenia, which causes numerous morbidities and economic burdens in human populations. Mechanisms implicated in age-related sarcopenia or frailty include inflammation, muscle stem cell depletion, mitochondrial dysfunction, and loss of motor neurons, but whether there are key drivers of sarcopenia are not yet known. To gain deeper insights into age-related muscle loss, we performed transcriptome profiling on lower limb muscle biopsies from 72 young, elderly, and frail human subjects using bulk RNA-seq (N = 72) and single-nuclei RNA-seq (N = 17). This combined approach revealed changes in gene expression that occur with age and frailty in multiple cell types comprising mature skeletal muscle. Notably, we found increased expression of the genes MYH8 and PDK4, and decreased expression of the gene IGFN1, in aged muscle. We validated several key genes changes in fixed human muscle tissue using digital spatial profiling. We also identified a small population of nuclei that express CDKN1A, present only in aged samples, consistent with p21cip1-driven senescence in this subpopulation. Overall, our findings identify unique cellular subpopulations in aged and sarcopenic skeletal muscle, which will facilitate the development of new therapeutic strategies to combat age-related frailty.

Muscle loss 6 months after surgery predicts poor survival of patients with non-metastatic colorectal cancer

Background

Muscle loss is a common characteristic of cancer-related malnutrition and a predictor of poorer prognosis in oncological patients. This study evaluated the association between altered body composition 6 months after surgery and the prognosis in patients with non-metastatic colorectal cancer.

Materials and methods

A total of 314 patients who underwent elective curative surgery were enrolled in the study. The third lumbar CT images on preoperative and 6-months postoperative were collected to calculate the skeletal muscle index (SMI), visceral adiposity index (VATI), and subcutaneous adiposity index (SATI). Sarcopenia was defined by the cut-off values reported in the literature, and risk factors affecting overall survival (OS) and disease-free survival (DFS) in CRC were analyzed using Cox regression models.

Results

Eighty-two of 314 patients (26.1%) with CRC were diagnosed with sarcopenia before surgery, the preoperative sarcopenia was not significantly associated with the prognosis of CRC patients. There were significant differences in frequency of complications between patient groups according to sarcopenia (41.5 vs. 21.4%, p = 0.004). The Postoperative LOS (11.21 ± 3.04 vs. 8.92 ± 2.84, p &lt; 0.001) was longer in the sarcopenia group than in the non-sarcopenia group, and 30-d readmission (24.4 vs. 6.0%, p &lt; 0.001) was higher in the sarcopenia group compared to the non-sarcopenia group. In multivariate analysis, 6-months SMI loss &gt; 10% after surgery was independently associated with poorer OS [hazard ratio (HR) = 3.74; 95% confidence interval (CI) 1.96 to 7.12; P &lt; 0.001] and DFS (HR = 3.33; 95% CI, 1.71 to 6.47; P &lt; 0.001). SMI changes were moderately correlated with changes in body mass index (BMI) (R = 0.47, P &lt; 0.001).

Conclusion

6-months muscle loss after surgery may affect overall and disease-free survival and was an independent predictor of prognosis in patients with CRC.

Use of the Visceral Adiposity Index as an Indicator of Chronic Kidney Disease in Older Adults: Comparison with Body Mass Index

The visceral adiposity index (VAI) was recently introduced to quantify visceral fat accumulation and dysfunction. This cross-sectional study explored whether the VAI is associated with chronic kidney disease (CKD) in older adults and compared its utility with that of body mass index (BMI) for predicting CKD. In total, 7736 older adults (3479 men and 4257 women) aged ≥ 60 years were divided into normal, mild, and moderate-to-severe CKD groups. Associations of the VAI and BMI with CKD were compared among the groups, and cut-off points for moderate-to-severe CKD (MSCKD) were established. While the VAI could discriminate among all of the groups, the BMI could not. The severity of CKD was more strongly associated with the VAI than BMI. The odds ratios indicated that, in the fully adjusted model, the VAI was a significant predictor of MSCKD in both men and women, while the BMI was a significant predictor only in men. For the VAI, the area under the receiver operating characteristic curve values for men and women were 0.631 (cut-off point: ≥2.993) and 0.588 (≥4.001), compared with 0.555 (≥25.335) and 0.533 (≥24.096) for BMI, respectively. Taken together, the findings suggest that the VAI is associated with CKD and represents a better indicator for the disease than BMI.