Gender differences in risk factors for the 2 year development of sarcopenia in community-dwelling older adults

Characterizing the skeletal muscle immune microenvironment for sarcopenia: insights from transcriptome analysis and histological validation

Background

Sarcopenia is a condition characterized by the age-related loss of skeletal muscle mass and function. The pathogenesis of the disease is influenced by chronic low-grade inflammation. However, the specific changes in the immune landscape changes of sarcopenic muscle are not yet fully understood.

Methods

To gain insights into the immune cell composition and interactions, we combined single-nucleus RNA sequencing data, bulk RNA sequencing dataset, and comprehensive bioinformatic analyses on the skeletal muscle samples from young, aged, and sarcopenic individuals. Histological staining was then performed on skeletal muscles to validate the distribution of immune cells in clinical samples.

Results

We analyzed the transcriptomes of 101,862 single nuclei, revealing a total of 10 major cell types and 6 subclusters of immune cell types within the human skeletal muscle tissues. Notable variations were identified in the immune microenvironment between young and aged skeletal muscle. Among the immune cells from skeletal muscle microenvironment, macrophages constituted the largest fraction. A specific marker gene LYVE1 for skeletal muscle resident macrophages was further identified. Cellular subclasses included four distinct groups of resident macrophages, which play different roles in physiological or non-physiological conditions. Utilizing bulk RNA sequencing data, we observed a significant enrichment of macrophage-rich inflammation in sarcopenia.

Conclusions

Our findings demonstrate age-related changes in the composition and cross-talk of immune cells in human skeletal muscle microenvironment, which contribute to chronic inflammation in aged or sarcopenia muscle. Furthermore, macrophages emerge as a potential therapeutic target, thus advancing our understanding of the pathogenesis of sarcopenia.

Adverse postoperative outcomes in elderly patients with sarcopenia

PURPOSE

No study has compared 30-day and 90-day adverse postoperative outcomes between old-age patients with and those without sarcopenia.

PATIENTS AND METHODS

We categorize elderly patients receiving major surgery into two groups according to the presence or absence of preoperative sarcopenia that were matched at a 1:4 ratio through propensity score matching (PSM). We analyzed 30-day or 90-day adverse postoperative outcomes and mortality in patients with and without sarcopenia receiving major surgery.

RESULTS

Multivariate logistic regression analyses revealed that the patients with preoperative sarcopenia were at significantly higher risk of 30-day postoperative mortality (adjusted odds ratio [aOR]. = 1.25; 95% confidence interval [CI]. = 1.03-1.52) and 30-day major complications such as postoperative pneumonia (aOR = 1.15; 95% CI = 1.00-1.40), postoperative bleeding (aOR = 2.18; 95% CI = 1.04-4.57), septicemia (aOR = 1.31; 95% CI = 1.03-1.66), and overall complications (aOR = 1.13; 95% CI = 1.00-1.46). In addition, surgical patients with sarcopenia were at significantly higher risk of 90-day postoperative mortality (aOR = 1.50; 95% CI = 1.29-1.74) and 90-day major complications such as pneumonia (aOR = 1.27; 95% CI = 1.10-1.47), postoperative bleeding (aOR = 1.90; 95% CI = 1.04-3.48), septicemia (aOR = 1.52; 95% CI = 1.28-1.82), and overall complications (aOR = 1.24; 95% CI = 1.08-1.42).

CONCLUSIONS

Sarcopenia is an independent risk factor for 30-day and 90-day adverse postoperative outcomes such as pneumonia, postoperative bleeding, and septicemia and increases 30-day and 90-day postoperative mortality among patients receiving major surgery. No study has compared 30-day and 90-day adverse postoperative outcomes between patients with and those without sarcopenia. We conducted a propensity score?matched (PSM) population-based cohort study to investigate the adverse postoperative outcomes and mortality in patients undergoing major elective surgery with preoperative sarcopenia versus those without preoperative sarcopenia. We demonstrated that sarcopenia is an independent risk factor for 30-day and 90-day adverse postoperative outcomes, such as postoperative pneumonia, bleeding, septicemia, and mortality after major surgery. Therefore, surgeons and anesthesiologists should attempt to correct preoperative sarcopenia, swallowing function, and respiratory muscle training before elective surgery to reduce postoperative complications that contribute to the decrease in surgical mortality.

Association between non-alcoholic fatty liver disease and risk of sarcopenia: a systematic review and meta-analysis

OBJECTIVES

To determine the association of non-alcoholic fatty liver disease (NAFLD) with the incidence of sarcopenia.

DESIGN

Systematic review and meta-analysis of observational clinical studies.

SETTING AND PARTICIPANTS

Adults with NAFLD.

METHODS

Databases such as PubMed, Embase, Cochrane and Web of Science were searched for eligible studies published from the inception of each database up to 4 April 2023. All cross-sectional studies on the association between NAFLD and sarcopenia were included in this study. The quality of the included studies and risk of bias was assessed using the Agency for Healthcare Research and Quality checklist. STATA V.15.1 software was used for statistical analysis.

RESULTS

Of the 1524 retrieved articles, 24 were included in this review, involving 88 609 participants. Our findings showed that the prevalence of sarcopenia was higher in the NAFLD group than in the control group (pooled OR 1.74, 95% CI 1.39 to 2.17). In a subgroup analysis by region, patients with NAFLD showed an increased risk of sarcopenia (pooled OR 1.97, 95% CI 1.54 to 2.51) in the Asian group, whereas patients with NAFLD had no statistically significant association with the risk of sarcopenia in the American and European groups, with a pooled OR of 1.31 (95% CI 0.71 to 2.40) for the American group and a pooled OR of 0.99 (95% CI 0.21 to 4.69) for the European group. Similar results were observed in the sensitivity analysis, and no evidence of publication bias was observed.

CONCLUSIONS AND IMPLICATIONS

The current study indicated a significant positive correlation between NAFLD and sarcopenia, which may be affected by regional factors. This study provides the correlation basis for the relationship between NAFLD and sarcopenia and helps to find the quality strategy of sarcopenia targeting NAFLD.

Protein Intake and Physical Activity Levels as Determinants of Sarcopenia Risk in Community-Dwelling Older Adults

Community screening for sarcopenia is complex, with barriers including access to specialized equipment and trained staff to conduct body composition, strength and function assessment. In the current study, self-reported dietary protein intake and physical activity (PA) in adults ≥65 years was assessed relative to sarcopenia risk, as determined by body composition, strength and physical function assessments, consistent with the European Working Group on Sarcopenia in Older People (EWGSOP) definition. Of those screened (n = 632), 92 participants (77% female) were assessed as being at high risk of developing sarcopenia on the basis of dietary protein intake ≤1 g∙kg-1∙day-1 [0.9 (0.7-0.9) g∙kg-1∙day-1] and moderate intensity physical activity <150 min.week-1. A further 31 participants (65% female) were defined as being at low risk, with both protein intake [1.2 (1.1-1.5) g∙kg-1∙day-1] and PA greater than the cut-off values. High-risk participants had reduced % lean mass [53.5 (7.8)% versus 54.8 (6.1)%, p < 0.001] and impaired strength and physical function. Notably, high-risk females exhibited greater deficits in lean mass and strength, with minimal differences between groups for males. In community-dwelling older adults, self-reported low protein intake and low weekly PA is associated with heightened risk for sarcopenia, particularly in older women. Future research should determine whether early intervention in older adults with low protein intake and PA attenuates functional decline.

Persistence of analgesic usage and opioid consumption in sarcopenic patients undergoing neuraxial anesthesia: a nationwide retrospective cohort study

Introduction

This study investigates the association between chronic postsurgical pain (CPSP) and long-term postsurgical analgesic usage in patients undergoing neuraxial anesthesia, with a specific focus on the presence or absence of sarcopenia.

Objectives

To assess the rate of analgesic prescription, including opioids, at 3 and 6 months postsurgery for patients with and without preoperative sarcopenia, and to determine the impact of sarcopenia on analgesic use after neuraxial anesthesia surgery.

Methods

Patients undergoing surgery under neuraxial anesthesia were categorized into sarcopenic and nonsarcopenic groups based on preoperative diagnosis using the ICD-10-CM code M62.84. Propensity score matching in a 1:4 ratio was applied for group matching. Analgesic prescription rates were evaluated at 3 and 6 months postsurgery, and multivariable logistic regression was used to analyze analgesic use, comparing patients with and without preoperative sarcopenia.

Results

Among 3805 surgical patients, 761 had sarcopenia, while 3044 did not. At 3 months postsurgery, 62.3% of sarcopenic patients received analgesics, with 2.9% receiving opioids, compared to 57.1% of nonsarcopenic patients receiving analgesics and 0.8% receiving opioids. At 6 months postsurgery, 30.8% of sarcopenic patients received analgesics (1.7% opioids), while 26.3% of non-sarcopenic patients received analgesics (0.3% opioids). Multivariable logistic regression analysis revealed that preoperative sarcopenia was significantly associated with higher analgesic prescription rates at both 3 months (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.05-1.53) and 6 months (aOR, 1.17; 95% CI, 1.07-1.42) postsurgery. Furthermore, sarcopenic patients exhibited significantly higher opioid prescription rates at 3 months (aOR, 1.11; 95% CI, 1.05-2.45) and 6 months (aOR, 1.89; 95% CI, 1.12-4.96) postsurgery.

Conclusion

Sarcopenia emerges as an independent risk factor for prolonged analgesic use after neuraxial anesthesia surgery and significantly elevates the risk of developing CPSP.

Household use of solid fuel and sarcopenia among middle-aged and older adults: The China Health and Retirement Longitudinal Study

OBJECTIVE

Few studies have examined the effects of air pollution on the risk of sarcopenia, especially pollution in indoor settings. We explored the cross-sectional and longitudinal associations of household use of solid fuel for cooking and heating, separately and simultaneously, with risk of sarcopenia.

METHODS

Cross-sectional and follow-up data from the China Health and Retirement Longitudinal Study were used. Multivariable-adjusted generalized linear models and Cox proportional hazards regression models were performed to estimate the odds ratio and hazard ratio for sarcopenia, respectively.

RESULTS

11,494 (median age: 57.0 years; 47.4 % males) and 7483 (median age: 57.0 years; 46.9 % males) participants were included in the cross-sectional and longitudinal study, respectively. After fully adjusting for covariates, including outdoor concentration of particulate matter (PM2.5), both the use of solid fuels for cooking and use for heating were positively associated with incident sarcopenia in the longitudinal analyses, with hazard ratios (95 % confidence interval) of 1.56 (1.28-1.89) and 1.26 (1.04-1.52), respectively. Moreover, significant multiplicative and/or additive interactions were observed between age, smoking and cooking with solid fuel and risk of sarcopenia (all P for interaction <0.05). Similar results were found in the cross-sectional analyses.

CONCLUSIONS

Household use of solid fuel was significantly associated with a higher risk of sarcopenia, while ageing and smoking had synergetic effects with burning solid fuels on the risk of sarcopenia. Our results highlight the importance of taking multi-pronged measures with respect to both air pollution and healthy lifestyle to prevent sarcopenia and promote healthy ageing.

A bidirectional Mendelian randomization study of sarcopenia-related traits and inflammatory bowel diseases

Background

There is increasing evidence pointing to a close relationship between sarcopenia and inflammatory bowel disease. However, it remains unclear whether or in which direction causal relationships exist, because these associations could be confounded.

Methods

We conducted a two-sample bidirectional mendelian randomization analysis using data from European genome-wide association studies of the appendicular lean mass(n = 450,243), walking pace(n = 459,915), grip strength (left hand, n = 461,026; right hand, n = 461,089), inflammatory bowel disease (25,042 patients and 34,915 controls), ulcerative colitis (12,366 patients and 33,609 controls), and Crohn's disease (12,194 patients and 28,072 controls) to investigate the causal relationship between sarcopenia-related traits and inflammatory bowel disease and its subtypes on each other. The inverse-variance weighted method was used as the primary analysis method to assess the causality, and a comprehensive sensitivity test was conducted.

Results

Genetically predicted appendicular lean mass was significantly associated with inflammatory bowel disease (OR = 0.916, 95%CI: 0.853-0.984, P = 0.017), ulcerative colitis (OR =0.888, 95%CI: 0.813-0.971, P = 0.009), and Crohn's disease (OR = 0.905, 95%CI: 0.820-0.999, P = 0.049). Similar results also revealed that the usual walking pace was causally associated with Crohn's disease (OR = 0.467, 95%CI: 0.239-0.914, P = 0.026). Reverse mendelian randomization analysis results found that genetic susceptibility to inflammatory bowel disease, and Crohn's disease were associated with lower appendicular lean mass. A series of sensitivity analyses ensured the reliability of the present research results.

Conclusion

The mendelian randomization study supports a bidirectional causality between inflammatory bowel disease, Crohn's disease and appendicular lean mass, but no such bidirectional causal relationship was found in ulcerative colitis. In addition, genetically predicted usual walking pace may reduce the risk of Crohn's disease. These findings have clinical implications for sarcopenia and inflammatory bowel disease management.

Factors Associated with Sarcopenia among Elderly Individuals Residing in Community and Nursing Home Settings: A Systematic Review with a Meta-Analysis

To investigate the factors associated with sarcopenia in elderly individuals residing in nursing homes and community settings, we conducted a systematic search of databases, including MEDLINE, EMBASE, PubMed, Web of Science and Cochrane, up to May 2023. We incorporated a total of 70 studies into our analysis. Our findings revealed that the prevalence of sarcopenia in nursing homes ranged from 25% to 73.7%, while in community settings, it varied from 5.2% to 62.7%. The factors associated with sarcopenia in both nursing homes and community settings included male gender, BMI, malnutrition, and osteoarthritis. In community settings, these factors comprised age, poor nutrition status, small calf circumference, smoking, physical inactivity, cognitive impairment, diabetes, depression and heart disease. Currently, both the European Working Group on Sarcopenia in Older People (EWGSOP) and the Asian Working Group for Sarcopenia (AWGS) standards are widely utilized in nursing homes and community settings, with the EWGSOP standard being more applicable to nursing homes. Identifying factors associated with sarcopenia is of paramount significance, particularly considering that some of them can be modified and managed. Further research is warranted to investigate the impact of preventive measures on these factors in the management of sarcopenia among elderly individuals residing in nursing homes and community settings.

Untailored vs. Gender- and Body-Mass-Index-Tailored Skeletal Muscle Mass Index (SMI) to Assess Sarcopenia in Advanced Head and Neck Squamous Cell Carcinoma (HNSCC)

(1) Background: Sarcopenia lasting >1 year might be considered a chronic condition in many HNSCC patients. CT-scan-derived Skeletal Muscle Mass Index (SMI) is an established surrogate of sarcopenia; yet, the cut-off reported in the literature (literature-based, lb-SMI < 43.2) is mainly based on the risk of chemoradiotherapy-induced toxicity, and the optimal value to discriminate OS is under-investigated. (2) Methods: The effect on OS of the lb-SMI cutoff was compared with an untailored OS-oriented SMI cutoff obtained in a cohort of consecutive advanced HNSCC patients treated with primary chemoradiotherapy, bio-chemotherapy or chemo-immunotherapy (cohort-specific, cs-SMI cutoff). Gender- and BMI-tailored (gt-SMI and bt-SMI) cut-offs were also evaluated. Cutoff values were identified by using the maximally selected rank statistics for OS. (3) Results: In 115 HNSCC patients, the cs-SMI cutoff was 31.50, which was lower compared to the lb-SMI reported cut-off. The optimal cut-off separately determined in females, males, overweight and non-overweight patients were 46.02, 34.37, 27.32 and 34.73, respectively. gt-SMI categorization had the highest effect on survival (p < 0.0001); its prognostic value was independent of the treatment setting or the primary location and was retained in a multivariate cox-regression analysis for OS including other HNSCC-specific prognostic factors (p = 0.0004). (4) Conclusions: A tailored SMI assessment would improve clinical management of sarcopenia in chemoradiotherapy-, bio-chemotherapy- or chemo-immunotherapy-treated HNSCC patients. Gender-based SMI could be used for prognostication in HNSCC patients.

Gender Disparity in Expression of Sarcopenia in Haemodialysis Recipients: Analysis from the FITNESS Cohort

Background

There has been little exploration of the interplay between sarcopenia and frailty in haemodialysis, particularly regarding gender difference. We aimed to (1) assess whether ultrasound-derived low muscle mass (LMM) and sarcopenia are more common in male or female haemodialysis recipients; (2) assess whether age influences any observed gender difference, and (3) explore the interplay between sarcopenia, frailty, and gender in haemodialysis recipients.

Methods

This was an exploratory analysis of a subgroup of adult prevalent (≥3 months) haemodialysis with frailty phenotype (FP) scores. Bilateral anterior thigh thickness (BATT) was obtained according to an established ultrasound protocol. Associations with frailty were explored via both linear and logistic regressions for BATT, LMM, and sarcopenia with a priori covariables, stratified by gender.

Results

In total of 223 studies, participants had ultrasound measurements. Males showed greater prevalence of LMM. On adjusted analyses, LMM was associated with lower hand grip strength in males (β = -4.17; 95% C.I. -7.57 to -0.77; P=0.02), but not females (β = -1.88; 95% C.I. -5.41 to 1.64; P=0.29). LMM was also associated with slower walking speed in both males (β = -0.115; 95% C.I. -0.258 to -0.013; P=0.03) and females (β = -0.152; 95% C.I. -0.300 to -0.005; P=0.04). Sarcopenia was associated with greater odds of frailty on adjusted models in males (OR = 9.86; 95% C.I. 1.8 to 54.0; P=0.01), but not females (OR = 5.16; 95% C.I. 0.22 to 124; P=0.31).

Conclusions

The clinical expression and significance of sarcopenia differ substantially between males and females on haemodialysis. Further work is required to elucidate underlying mechanisms and guide tailored treatment.

Preoperative low absolute and relative handgrip strength as predictors of postoperative short-term outcomes: a prospective study based on patients aged 60 years and older with gastric cancer

PURPOSE

This study aimed to determine the association of absolute and relative HGS indicators with postoperative short-term outcomes in older patients with gastric cancer.

METHODS

The prospective, single-center, observational study involved 230 patients (age ≥ 60 years) who underwent radical gastrectomy. Absolute HGS was directly obtained from results measured by a hand dynamometer, while relative HGS was calculated as the value of absolute HGS divided by body mass index (BMI), appendicular skeletal muscle mass index (ASMI) and age, respectively. Low absolute HGS was defined according to the criterion in AWGS 2019 consensus and the first gender-specific quartile. Low relative handgrip strength was defined if it was below the first gender-specific quartile of the distribution. Postoperative outcomes included total complications, malnutrition and length of hospital stay. Univariate and multivariate regression models were performed to investigate and compare the predictive values of different HGS indicators.

RESULTS

For the five HGS indicators, multivariate analyses showed that low absolute HGS (AWGS consensus), low HGS/BMI and HGS/age were independent risk factors for both postoperative total complications (absolute HGS(AWGS consensus): OR  2.03, 95%CI:1.05-3.93; HGS/BMI: OR  2.12, 95%CI 1.05-4.28; HGS/age: OR  2.79, 95%CI 1.40-5.54) and malnutrition (absolute HGS(AWGS consensus): OR   2.01, 95%CI 1.10-3.67; HGS/BMI: OR  2.28, 95%CI 1.20-4.33; HGS/age: OR   2.70, 95%CI 1.42-5.14). Low absolute HGS (quartile) was an independent risk factor for malnutrition (OR   1.96, 95%CI 1.04-3.71). Moreover, Low HGS/age was associated with lengthened postoperative hospital stay (OR  2.07, 95%CI 1.12-3.85).

CONCLUSIONS

Except HGS/ASMI, both absolute and relative HGS indicators were associated with postoperative short-term outcomes. Particularly, HGS/age revealed relatively better predictive value for the studied outcomes.

Assessing causal relationships between sarcopenia and nonalcoholic fatty liver disease: A bidirectional Mendelian randomization study

BACKGROUND AND AIMS

Sarcopenia has been demonstrated to be closely associated with nonalcoholic fatty liver disease (NAFLD). However, whether there are causal relationships between sarcopenia and NAFLD remains undetermined. Here, we aim to address the question using a two-sample bidirectional Mendelian randomization (MR) analysis approach.

METHODS

We performed a two-sample bidirectional MR study using summary-level data from genome-wide association studies (GWAS) of the whole body lean mass (n = 38,292), appendicular (arms and legs) lean mass (n = 28,330), and NAFLD (1,483 biopsy-proven NAFLD cases and 17,781 controls). We first conducted MR analysis with five single nucleotide polymorphisms (SNPs) as genetic instruments for whole body lean mass and three SNPs as instruments for appendicular lean mass to estimate the causal effect of genetically predicted sarcopenia on the risk of NAFLD using the inverse-variance weighted (IVW) method. Then we performed reverse MR analysis with four SNPs as instruments to examine the causality of genetically predicted NAFLD with whole body lean mass and appendicular lean mass. Further sensitivity analysis was conducted to testify the reliability of the MR results.

RESULTS

Genetic predisposition to decreased whole body lean mass was not associated with NAFLD [IVW-random effects, odds ratio (OR) = 1.054, 95%CI: 0.750-1.482, P = 0.761]. Similar results were observed using genetic instruments of appendicular lean mass (IVW-random effects, OR = 0.888, 95%CI: 0.386-2.042, P = 0.780). Reverse MR analysis revealed that genetically predicted NAFLD using four genetic instruments was not associated with whole body lean mass (IVW, β = -0.068, 95%CI: -0.179 to 0.043, P = 0.229) and appendicular lean mass (IVW, β = -0.020, 95%CI: -0.092 to 0.051, P = 0.574). MR analyses using other methods and sensitivity analysis showed consistent results.

CONCLUSION

These results suggested no causal relationships between sarcopenia and NAFLD, indicating that sarcopenia may not be directly involved in the pathogenesis of NAFLD and vice versa.

A Nutritionally Complete Oral Nutritional Supplement Powder Improved Nutritional Outcomes in Free-Living Adults at Risk of Malnutrition: A Randomized Controlled Trial

BACKGROUND

This randomized controlled trial investigated the effectiveness of an oral nutritional supplement (ONS) on nutrition-related outcomes over 12 weeks in Chinese adults with or at risk of malnutrition.

METHODS

88 Chinese adults ≥18 years living independently in Hong Kong with Mini Nutritional Assessment-Short Form (MNA-SF) score ≤11 were randomly assigned to (1) 2 servings/day of nutritionally complete ONS powder made with water (Fresubin^® Powder (Fresubin Kabi Deutschland GmbH, Bad Homburg, Germany), 600 kcal, 22.4 g protein) for 12 weeks (intervention group) or (2) no treatment (control group). The primary outcome was increase in body weight (BW) over 12 weeks. Secondary outcomes included improvement in body mass index (BMI), mid-arm circumference (MAC), calf circumference, MNA-SF score, quality of life, self-rated health, frailty, and diet quality.

RESULTS

The intervention group showed a significantly higher mean increase in BW compared with the control group (1.381 kg, intervention vs control, p < 0.001). The intervention group also showed significantly higher mean increases in BMI, MAC, calf circumference, intake of energy, protein, vitamin D, and calcium compared with the control group. No group differences in the changes of other outcomes were observed.

CONCLUSIONS

For Chinese free-living adults at risk of malnutrition, daily consumption of a nutritionally complete ONS powder improved nutritional outcomes compared with the control group.

Rehabilitation of Older Adults with Sarcopenia: From Cell to Functioning

The 20th and 21st centuries have witnessed a substantial increase in human life expectancy and in the number of men and women aged 60 years and older. Aging is associated with a large number of health conditions, including sarcopenia, which has been the subject of important research in the past 30 years. Sarcopenia is characterized by an age-related loss of muscle mass, weakness, and impaired physical performance. The condition can be diagnosed with a combination of measurements of these three elements. The precise definition of sarcopenia and the selection of optimal assessment methods have changed significantly in the past 20 years; nonetheless, the prevalence of sarcopenia in the general older population is in the range of 5–15%. Molecular and cellular events at the muscle cell level impact the size and quality of muscles (force adjusted for size). The active and passive mechanical properties of single muscle fibers are altered by changes in the structure and function of various cellular elements. Systemic factors such as inflammation, loss of hormonal influence, and deleterious lifestyle choices also contribute to sarcopenia. The consequences of sarcopenia include many adverse effects such as impairments in activities of daily living, falls, loss of independence, and increased mortality. Several rehabilitative interventions have been tested, and the safest and most effective is the use of progressive resistance exercise. An increase in dietary protein intake has synergistic effects. Future research should focus on a consensus definition of sarcopenia, identification of the best assessment methods, understanding of biological mechanisms, and testing of innovative interventions.