Prevalence of sarcopenia in patients with rheumatoid arthritis using the revised EWGSOP2 and the FNIH definition

Prevalence and Associated Factors of Sarcopenia in Thai Rheumatoid Arthritis Patients: A Cross-Sectional Study

BACKGROUND/OBJECTIVES

Sarcopenia associates with poor health-related quality of life (HRQoL). This study aimed to determine prevalence and factors associated with sarcopenia in rheumatoid arthritis (RA) patients. The HRQoL between RA patients with and without sarcopenia also was compared.

METHODS

This cross-sectional study recruited RA patients, aged ≥20 years, at Chiang Mai University Hospital between May and November 2023. Their skeletal muscle mass (bioelectrical impedance analysis), grip strength (hand dynamometer), and physical performance (gait speed test) were evaluated. Sarcopenia was defined according to the Asian Working Group for Sarcopenia. Patient characteristics, disease activity, physical disability (HAQ-DI), HRQoL (SF-36), nutrition (mini nutrition assessment), and medications were recorded.

RESULTS

Of 299 patients (89.0% female; age 61.3 ± 11.6 years; disease duration 13.9 ± 8.6 years), 37.5% had sarcopenia (27.4% severe sarcopenia). In multivariable analysis, body mass index (odds ratio [95% confidence interval] 1.46/1 unit decrease [1.27, 1.68], p < 0.001), disease duration (1.89/10 years increase [1.27, 2.83], p = 0.002), deformity of hands/feet (3.80 [1.50, 9.61], p = 0.005), mini nutritional assessment score (1.21/1 score decrease [1.04, 1.40], p = 0.012), and high C-reactive protein (CRP) (1.94 [1.02, 3.69], p = 0.044) were independent factors associated with sarcopenia. There was no relationship between sarcopenia and disease activity (DAS-28-ESR or CRP) or medication use. RA patients with sarcopenia had higher HAQ score than those without, but potentially lower scores in physical function domain of SF-36 with adjusted mean difference of 0.2 (95% confidence interval 0.03, 0.32, p = 0.022) and -5.9 (-12.24, 0.38, p = 0.066), respectively.

CONCLUSIONS

About one third of the Thai RA patients in this center had sarcopenia. Low body mass index, long disease duration, joint deformity, malnutrition, and high CRP were independent factors associated with sarcopenia. Sarcopenia affects physical capabilities and the physical function domain of the HRQoL.

Systemic Inflammation and Disruption of the Local Microenvironment Compromise Muscle Regeneration: Critical Pathogenesis of Autoimmune-Associated Sarcopenia

Unlabelled

Sarcopenia is defined by age-related reductions in muscle mass, strength, and physiological function, and it is especially prevalent among individuals with autoimmune diseases. Autoimmune disorders, characterized by immune dysregulation, cause systemic inflammation and damage to multiple tissues through unregulated immune activity. Research indicates that autoimmune diseases negatively impact skeletal muscle functions and may worsen the progression of sarcopenia. This viewpoint comprehensively discusses the pathogenesis and potential mechanism of sarcopenia in 3 autoimmune diseases: inflammatory bowel disease, rheumatoid arthritis, and type 1 diabetes mellitus. Mechanistically, chronic immune microenvironment alterations induce compartment-specific redistribution of leukocyte subsets and cytokine networks. These perturbations disrupt critical signaling pathways governing muscle protein synthesis, satellite cell activation, and mitochondrial bioenergetics, leading to impaired regeneration and accelerated sarcopenia progression. By delineating shared and distinct pathomechanisms across these models, this analysis reframes our understanding of immune-mediated muscle wasting. Beyond mechanistic insights, it establishes a translational framework for targeted therapies and highlights emerging research directions bridging immunology and age-related musculoskeletal decline.

Molecular crosstalk and potential causal mechanisms of rheumatoid arthritis and sarcopenia co-morbidity: A gene integration analysis

INTRODUCTION

Rheumatoid arthritis (RA) promotes the onset and progression of sarcopenia, yet mechanisms of co-morbidity between RA and sarcopenia are under-explored. Therefore, this study integrated Gene Expression Omnibus (GEO) and Genome-wide association studies (GWAS) data to comprehensively identify shared genes, associated mechanisms, and biological pathways in RA and sarcopenia.

METHODS

Utilizing two GEO datasets-GSE226151, which includes 60 RNA-seq samples of skeletal muscle from healthy aged, pre-sarcopenia, and sarcopenia individuals, and GSE55235, with 20 RNA-seq samples of synovial tissue from healthy and RA joints-we performed differentially expressed genes analysis, weighted gene co-expression network analysis to identify crosstalk genes in RA and sarcopenia, and enrichment analysis for these genes. Using relevant GWAS datasets, SMR analyses and cis-eQTL analyses were performed. We further validated and identified key crosstalk genes and explored potential causal associations between key crosstalk genes and RA and sarcopenia-related traits.

RESULTS

We identified 25 crosstalk genes shared between RA and sarcopenia, which are involved in immune-inflammatory response pathways, including neutrophil extracellular trap formation and Fc gamma receptor-mediated phagocytosis. SMR analysis further identified six core crosstalk genes: NCF1, FCGR2A, FCGR3A, SORL1, FCGR3B, and ITGAX (PSMR < 0.05). cis-eQTL analysis showed that FCGR2A might have a negative causal association with appendicular lean mass, whole body fat-free mass, and a positive causal association with RA (P < 0.05).

CONCLUSION

Overall, this study is the first to reveal the molecular crosstalk between RA and sarcopenia, identifying 25 shared genes and key immune-inflammatory response-related pathways. Further SMR and cis-eQTL analyses were conducted to validate six core genes, with FCGR2A emerging as a potential drug target for RA-associated sarcopenia. These findings provide new insights into the comorbid mechanisms of RA and sarcopenia, offering potential therapeutic targets for both conditions.

Management of Late-Onset Rheumatoid Arthritis with Treat-to-Target Strategy

The incidence of patients with late-onset rheumatoid arthritis (LORA) is increasing. The clinical diagnosis of LORA is essentially the same as that of young-onset rheumatoid arthritis (YORA), but special attention should be paid to the differences in clinical features between LORA and YORA. Undertreatment of LORA can lead to reduced physical function and increased societal burden. The treat-to-target strategy has been successfully applied in patients with rheumatoid arthritis (RA), but evidence supporting this strategy is still insufficient for LORA. A wide range of factors should be considered and evaluated in addition to age and RA-related factors, including comorbidity/organ damage, psycho-neurological factors, socio-economic factors and frailty. Considering the proportion of patients with LORA achieving clinical remission or low disease activity in observational studies, the treat-to-target strategy could be stratified by age. Patients with LORA aged < 75 years are treated according to the treat-to-target algorithm used for all patients with RA, with clinical remission as the main target and low disease activity as the alternative target. In patients with LORA aged ≥ 75 years, the initial main target is set at low disease activity, which can be escalated to clinical remission with appropriate adaptation of treatment if a favourable balance of effectiveness and safety is struck at the time of achieving low disease activity by 6 months of treatment. Evidence of the efficacy/effectiveness and safety of methotrexate, biological disease-modifying antirheumatic drugs, Janus kinase inhibitors and glucocorticoids in patients with LORA is accumulating, but further research is warranted.

Sarcopenia in Rheumatic Diseases: A Hidden Issue of Concern

Sarcopenia is characterized by a loss of muscle mass and function, with significant implications for the physical performance of the affected people. Although commonly associated with aging, disease-related sarcopenia is of great clinical importance, particularly as it impacts disease progression and outcomes. Individuals with rheumatic diseases (RDs), including rheumatoid arthritis, systemic sclerosis, spondyloarthritides, systemic lupus erythematosus, fibromyalgia, myositis, or vasculitis, exhibit a high prevalence of sarcopenia, which exacerbates their clinical symptoms and contributes to poorer disease outcomes. Chronic inflammation influences muscle tissue degradation, causing a decline in physical performance. Apart from the apparent clinical manifestations, patients with RDs also use pharmacological treatments that negatively impact muscle mass further, increasing the risk of sarcopenia. Nutrition (diet and dietary supplements) and exercise interventions have been recommended as protective measures for sarcopenia as they may mitigate its adverse events. The present narrative review seeks to explore the methods used to assess sarcopenia in patients with RDs, its prevalence among them, and the challenges faced by the affected individuals, while critically assessing the appropriateness and limitations of current sarcopenia assessment tools in the context of RDs.

Assessment of sarcopenia in young patients with inflammatory arthritis: a cross-sectional study

Sarcopenia is a disease characterized by decreasing muscle mass and strength or performance. The prevalence of sarcopenia in rheumatic diseases has been evaluated in single diseases using various diagnostic approaches, generating conflicting data. The study aims to investigate sarcopenia prevalence in young adults with inflammatory arthritis (IA) and to detect factors associated with low muscle mass and strength. The single-center, cross-sectional study included 138 young adults with IA. Dynamometry with a Jamar hand dynamometer was used to determine handgrip strength. Thresholds for reduced muscle strength were < 27 kg for males and < 16 kg for females. To determine skeletal mass index (SMI), dual photon X-ray absorptiometry (DXA) was done with such cut-off points < 5.67 kg/m2 in females and < 7.0 kg/m2 in males. Patients with both reduced muscle mass and strength were considered as sarcopenic. Logistic regression analyses estimated between sarcopenia and associated factors. Statistical significance was defined as a p-value < 0.05. The prevalence of sarcopenia was about 47% in all IA and was significantly different between juvenile idiopathic arthritis (JIA), spondyloarthritis (SpA), and rheumatoid arthritis (RA) groups (p = 0.006). At multivariable analysis, body mass index (BMI) (OR 0.84; CI 95% 0.72-0.86, p = 0.02), bone mineral density (BMD) at femur neck (OR 0.01; CI 95% 0.001-0.268, p = 0.01), 25-hydroxyvitamin D (25(OH)D) (OR 0.96; CI 95% 0.93-0.98, p = 0.001), and disability by Health Assessment Questionnaire (HAQ) (OR 14.54; CI 95% 4.92-51.77, p < 0.001) were associated with a significantly increased risk of sarcopenia. The results of our study demonstrate a high prevalence of sarcopenia among young patients with IA. In these participants, lower BMI, lower BMD, 25(OH)D concentration, and higher HAQ were linked to sarcopenia.

Sarcopenia and immune-mediated inflammatory diseases: Evaluating causality and exploring therapeutic targets for sarcopenia through Mendelian randomization

BACKGROUND

An increasing body of evidence has revealed the association between immune-mediated inflammatory diseases (IMIDs) and sarcopenia. However, a genetically direct causality between IMIDs and sarcopenia remains elusive.

METHODS

To investigate the relationship between IMIDs and sarcopenia-related traits and identify potential therapeutic targets, a Mendelian randomization (MR) was performed. We collected publicly available genome-wide association studies (GWAS) data for seven common IMIDs, including systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), Crohn's disease (CD), ulcerative colitis (UC), psoriasis (PSO), ankylosing spondylitis (AS), and rheumatoid arthritis (RA). Additionally, summary-level GWAS data for sarcopenia-related traits, including appendicular lean mass (ALM), left-hand grip strength, and right-hand grip strength were collected. To search for therapeutic targets, we used two types of genetic instruments to proxy the exposure of druggable genes, including genetic variants within or nearby drug targets and expression quantitative trait loci (eQTLs) of drug targets. Two-sample MR and summary-data-based MR (SMR) were used to calculate effect estimates, and sensitivity analyses were implemented for robustness. Drug tractability, gene enrichment analysis, and protein-protein interaction (PPI) analysis were used to validate the biological and clinical significance of the selected drug targets.

RESULTS

The two-sample MR analysis indicated the existence of casual associations between IMIDs and sarcopenia-related traits in the overall and sex-stratified populations. In particular, PSO had causal effects on decreased ALM, which showed significance in all six MR analysis tests with directional consistency in the overall population. Grounded in this robust association, HLA-DRB5, HLA-DRB1, and AGER were identified as potential therapeutic targets for ALM decline by drug target MR and further confirmed by SMR analysis. These genes were associated with therapeutic agents currently undergoing evaluations in clinical trials. Gene enrichment and PPI analysis indicated a strong association of these genes with immune functions.

CONCLUSIONS

This MR study contributes novel genetic evidence supporting the causal link between IMIDs and sarcopenia, with a particular emphasis on the association between PSO and decreased ALM. Additionally, AGER, HLA-DRB1, and HLA-DRB5 emerge as potential therapeutic targets for ALM decline.

Muscle Strength Comparison in Immune-Mediated Rheumatic Disease vs Healthy Adults: A Meta-Analysis

OBJECTIVES

Patients with immune-mediated rheumatic diseases (IMRDs) often exhibit reduced muscle strength. Therefore, this review aimed to evaluate muscle strength in patients with IMRDs compared with healthy control and to summarize the relationship between low muscle strength and clinical features in patients with IMRDs.

DESIGN

Systematic review with meta-analysis of case-control studies.

SETTING AND PARTICIPANTS

Patients with IMRDs.

METHODS

A comprehensive search was conducted in the Embase, MEDLINE, Web of Science, and Cochrane databases to identify relevant studies published up to November 2023 on rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and spondyloarthritis. Meta-analysis was performed using a random-effects model to determine the mean difference (MD) in muscle strength between patients with IMRDs and an age- and sex-matched healthy control group.

RESULTS

We identified 11,692 studies, and 760 studies were selected for screening. Ultimately, 26 studies met the inclusion criteria, composed of 2661 individuals, mostly women. The IMRDs women group had lower handgrip muscle strength (MD, -9.53; 95% CI, -11.78 to -7.28 kg) than the healthy control group, whereas the handgrip strength men groups did not differ significantly from that of the healthy control group. Similar trend was observed in lower limb muscle strength for the IMRDs women group than the healthy control group (MD, -63.10; 95% CI, -94.18 to -32.01 Nm). Four studies examined muscle strength and clinical features in rheumatoid arthritis: one associated it with age and disease activity, 2 associated it with disease duration, and 3 associated it with physical function. In systemic lupus erythematosus, only 2 studies associated low muscle strength with age, disease activity, and fatigue. No associations were found in spondyloarthritis, and none were found in systemic sclerosis.

CONCLUSIONS AND IMPLICATIONS

Patients with IMRD exhibit lower muscle strength than healthy counterparts, with low strength moderately associated with longer disease duration, worsening disease activity, and decline in physical function. Targeted interventions are crucial for preventing and managing muscle weakness in IMRDs.

Sarcopenia assessed by DXA and hand-grip dynamometer: a potential marker of damage, disability and myokines imbalance in inflammatory myopathies

OBJECTIVES

To assess the ability of dual-energy X-ray absorptiometry (DXA) and hand-grip dynamometer to measure damage in inflammatory myopathies (IM).

METHODS

Forty adult IM patients with a disease duration ≥12 months, low or no disease activity for ≥6 months, were prospectively enrolled. Thirty healthy age and sex-matched volunteers were enrolled as controls. Whole-body DXA and hand-grip dynamometer were used to measure muscle mass, grip strength and diagnose sarcopenia (EWGSOP2 criteria). Relationships between the results of strength in 12 muscles, functional tests, patient-reported disability, IMACS damage score, and history of the disease were assessed. The serum levels of potential molecular actors in the damage were measured.

RESULTS

DXA and grip strength measurements took ≤20 min. Both muscle mass and grip strength were decreased in IM patients vs volunteers (-10% and -30%, respectively) with a dispersion that varied widely (interquartile range -24.3% to +7.8% and -51.3% to -18.9%, respectively). Muscle mass and grip strength were non-redundantly correlated (r up to 0.6, P = 0.0001) with strength in 14 muscles (manual muscle test and hand-held dynamometer), functions (of limbs, respiratory and deglutition muscles), patient-reported disability, damage (extension and severity in muscular and extra-muscular domains) and blood levels of several myokines. Seven IM patients (17.5%) were sarcopenic. They had the worst damage, impaired functions, disability and history of severe myopathy. Decreased irisin and osteonectin levels were associated with sarcopenia (area under the curve 0.71 and 0.80, respectively).

CONCLUSION

DXA and hand-grip dynamometer are useful tools to assess damage in IM. Irisin and osteonectin may play a role in IM damage pathogenesis.

Inflammatory profile in patients with rheumatoid arthritis and sarcopenia

INTRODUCTION

Sarcopenia is characterized by the loss of muscle mass and strength associated with aging; however, individuals with chronic diseases are at risk at the early stages. In rheumatoid arthritis (RA), sustained chronic inflammation influences muscle deterioration. It may expedite the development of sarcopenia, which has been linked to physical disability, cardiovascular events, disease activity of RA, and premature death. We aimed to compare the inflammatory profiles of patients with RA with and without sarcopenia.

METHODS

This cross-sectional study involved 165 women with RA. Sarcopenia was diagnosed according to criteria established by the European Working Group on Sarcopenia in Older People. To assess the inflammatory profile, concentrations of cytokines such as EGF, IL-17, IL-1α, IL-1β, IL-6, TNFα, TNFβ, and creatine kinase (CK) were measured.

RESULTS

The prevalence of sarcopenia was 15.8% (95% CI: 8.9-18.2). The median age of patients with sarcopenia was 59.5 years (49.8-65.3), compared to 50 years (43-59 years) p = 0.001. The disease duration was also longer in patients with sarcopenia, 21 years (15-30), compared to those without sarcopenia, 13 years (7.3-20) p = 0.001. The inflammatory profile differed between patients with and without sarcopenia, revealing that the cytokines IL-1α, IL-6, and TNFβ concentrations were significantly higher (p < 0.05) in patients with sarcopenia, adjusted for BMI, age, and disease duration.

CONCLUSION

Patients with RA and sarcopenia were older and exhibited longer disease duration and higher levels of inflammatory cytokines compared to those without sarcopenia. These findings suggest potential implications for clinical outcomes. Key Points • The prevalence of sarcopenia in women with rheumatoid arthritis was 15.8% (95% CI, 8.9-18.2). • Levels of IL-1α, IL-6, and TNFβ cytokines were significantly higher in women with rheumatoid arthritis and sarcopenia compared with those without sarcopenia, adjusted for BMI, age, and disease duration.

Prevalence of Sarcopenia and Its Defining Components in Non-alcoholic Fatty Liver Disease Varies According to the Method of Assessment and Adjustment: Findings from the UK Biobank

Sarcopenia may increase non-alcoholic fatty liver disease (NAFLD) risk, but prevalence likely varies with different diagnostic criteria. This study examined the prevalence of sarcopenia and its defining components in adults with and without NAFLD and whether it varied by the method of muscle mass assessment [bioelectrical impedance (BIA) versus dual-energy X-ray absorptiometry (DXA)] and adjustment (height2 versus BMI). Adults (n = 7266) in the UK Biobank study (45-79 years) with and without NAFLD diagnosed by MRI, were included. Sarcopenia was defined by the 2018 European Working Group on Sarcopenia in Older People definition, with low appendicular skeletal muscle mass (ASM) assessed by BIA and DXA and adjusted for height2 or BMI. Overall, 21% of participants had NAFLD and the sex-specific prevalence of low muscle strength (3.6-7.2%) and sarcopenia (0.1-1.4%) did not differ by NAFLD status. However, NAFLD was associated with 74% (males) and 370% (females) higher prevalence of low ASM when adjusted for BMI but an 82% (males) to 89% (females) lower prevalence when adjusted for height2 (all P < 0.05). The prevalence of impaired physical function was 40% (males, P = 0.08) to 123% (females, P < 0.001) higher in NAFLD. In middle-aged and older adults, NAFLD was not associated with a higher prevalence of low muscle strength or sarcopenia but was associated with an increased risk of impaired physical function and low muscle mass when adjusted for BMI. These findings support the use of adiposity-based adjustments when assessing low muscle mass and the assessment of physical function in NAFLD.

Evaluating sarcopenia prevalence and SARC-F effectiveness in elderly Spanish women with RA: a comparative study of EWGSOP criteria

Introduction

The European Working Group on Sarcopenia in Older People (EWGSOP) has put forward two key proposals for diagnosing sarcopenia: the EWGSOP1 in 2010 and the EWGSOP2 in 2019. These proposals are currently the most widely used guidelines for diagnosing sarcopenia. However, data on the prevalence of sarcopenia in patients with rheumatoid arthritis (RA) based on EWGSOP criteria are limited. This study aimed to: (a) establish the prevalence of sarcopenia in an elderly Spanish cohort of women with RA using both EWGSOP1 and EWGSOP2 criteria; and (b) evaluate the effectiveness of the SARC-F questionnaire in detecting sarcopenia.

Methods

In this observational, cross-sectional study, 67 women aged over 65 years who met the ACR 2010 criteria for RA were consecutively recruited from a tertiary university hospital. Assessments included: (a) demographic and anthropometric data; (b) RA-related variables (disease history, analytical evaluation, activity, disability, quality of life); and (c) sarcopenia-related variables (muscle strength, gait speed, skeletal muscle mass, and SARC-F questionnaire). The prevalence of sarcopenia was determined using both EWGSOP1 and EWGSOP2 criteria. Furthermore, the effectiveness of the SARC-F questionnaire for detecting sarcopenia were calculated.

Results

The prevalence of sarcopenia was 43% according to the EWGSOP1 criteria and 16% according to the EWGSOP2 criteria. Patients diagnosed with sarcopenia based on the latter criteria also met the EWGSOP1's criteria for sarcopenia. Agreement between the two sets of EWGSOP criteria was poor. The SARC-F questionnaire demonstrated an inherently high sensitivity (100%) as well as good specificity (75%) and diagnostic accuracy (79%) in detecting sarcopenia according to EWGSOP2 criteria.

Conclusions

The prevalence rate of sarcopenia among elderly Spanish women with RA varies significantly depending on whether EWGSOP1 or EWGSOP2 criteria are applied. The SARC-F questionnaire is effective for predicting sarcopenia when used in conjunction with the EWGSOP2 criteria, which is currently the most accepted standard in clinical practice.

The relationships between sarcopenia, frailty, bioelectrical impedance analysis, and anthropometry in patients with type two intestinal failure

INTRODUCTION

SARC-F (Strength, Assistance in walking, Rise from a chair, Climb stairs and Falls) is a validated screening questionnaire for rapidly assessing sarcopenia in older adults with a variety of diseases while the Rockwood clinical frailty scale (RCFS) is a commonly used tool for assessing frailty in older adults. However, there are no data regarding the use of these tools in patients with type two intestinal failure (T2IF). We aimed to compare SARC-F and RCFS to bioelectrical impedance analysis (BIA) and anthropometry in patients with T2IF.

METHODS

In this cross-sectional study, patients with T2IF admitted to a national U.K. reference centre had SARC-F, RCFS, BIA and anthropometry performed. A SARC-F score ≥4 indicated potential sarcopenia while a RCFS ≥5 indicated frailty. Statistical analyses were conducted to assess correlation, concordance and differences between measurements.

RESULTS

The study comprised 76 patients, of whom 59.2 % were female, with a mean age of 56.5 years ± 16. Seventy percent of patients had short bowel syndrome as an underlying cause of IF. Thirty eight percent of patients had a SARC-F ≥4 and 20 % had a RCFS ≥5. SARC-F was correlated with RCFS (rs 0.43, p < 0.001), phase angle (PA) (rs -0.55, p < 0.001) and hand grip strength (HGS) (rs -0.34, p 0.004). RCFS was correlated with HGS (rs -0.31, p 0.009). Significant differences emerged between PA (p 0.002) and HGS (p 0.003) values in patients with SARC-F scores ≥4 and < 4 and with HGS for patients with RCFS ≥5 and < 5 (p 0.01). Patients with SARC-F scores ≥4 had longer lengths of stays than those with scores <4 (p 0.002). Compared to PA and HGS, SARC-F had sensitivities of 39 % and 37 % and specificities of 92 % and 73 % respectively.

CONCLUSION

We demonstrated SARC-F is correlated with PA and HGS with comparable sensitivity and specificity to its original use in older individuals. There is a role for SARC-F as a means of rapidly assessing muscle quality and function in hospitalised patients with IF with RCFS providing some useful information about muscle function.

[Frequency and severity of sarcopenia in patients with inflammatory and noninflammatory musculoskeletal diseases : Results of a monocentric study in a tertiary care center]

INTRODUCTION

Sarcopenia (SP) is defined as the pathological loss of muscle mass and function. This is a clinically relevant problem, especially in geriatric patients, because SP is associated with falls, frailty, loss of function, and increased mortality. People with inflammatory and degenerative rheumatic musculoskeletal disorders (RMD) are also at risk for developing SP; however, there is little research on the prevalence of this health disorder in this patient group using currently available SP criteria.

OBJECTIVE

To investigate the prevalence and severity of SP in patients with RMD.

METHODS

A total of 141 consecutive patients over 65 years of age with rheumatoid arthritis (RA), spondylarthritis (SpA), vasculitis, and noninflammatory musculoskeletal diseases were recruited in a cross-sectional study at a tertiary care center. The European Working Group on Sarcopenia in Older People (EWGSOP 1 and 2) definitions of presarcopenia, SP, and severe SP were used to determine the prevalence. Lean mass as a parameter of muscle mass and bone density were measured by dual X‑ray absorptiometry (DXA). Handgrip strength and the short physical performance battery (SPPB) were performed in a standardized manner. Furthermore, the frequency of falls and the presence of frailty were determined. Student's T-test and the χ2-test were used for statistics.

RESULTS

Of the patients included 73% were female, the mean age was 73 years and 80% had an inflammatory RMD. According to EWGSOP 2, 58.9% of participants probable had SP due to low muscle function. When muscle mass was added for confirmation, the prevalence of SP was 10.6%, 5.6% of whom had severe SP. The prevalence was numerically but not statistically different between inflammatory (11.5%) and noninflammatory RMD (7.1%). The prevalence of SP was highest in patients with RA (9.5%) and vasculitis (24%), and lowest in SpA (4%). Both osteoporosis (40% vs. 18.5%) and falls (15% vs. 8.6%) occurred more frequently in patients with SP than those without SP.

DISCUSSION

This study showed a relatively high prevalence of SP, especially in patients with RA and vasculitis. In patients at risk, measures to detect SP should routinely be performed in a standardized manner in the clinical practice. The high frequency of muscle function deficits in this study population supports the importance of measuring muscle mass in addition to bone density with DXA to confirm SP.

Association Between Autoimmune Diseases and Sarcopenia: A Two-Sample Mendelian Randomization Study

Purpose

Observational studies have reported that autoimmune diseases are closely related to sarcopenia, but the causalities of autoimmune diseases with sarcopenia have not been established. We conducted this Mendelian randomization (MR) study to reveal the causal associations of overall autoimmune disease and five common autoimmune diseases with sarcopenia-related traits.

Methods

The publicly available summary-level data of autoimmune diseases and three sarcopenia-related traits were used for analysis. The causal effects of autoimmune diseases on sarcopenia-related traits were first identified in discovery samples using the inverse-variance-weighted method as the primary method, and the robustness of results was examined by additional sensitivity analyses. Replication MR analyses were then conducted using replication samples of five autoimmune diseases. Finally, the possibility of reverse causation was assessed by reverse MR analyses.

Results

In both the discovery and replication samples, we identified potential causal effects of rheumatoid arthritis (RA) on appendicular lean mass (ALM) and low grip strength (OR = 0.979, 95% CI: 0.964-0.995 for ALM; OR = 1.042, 95% CI: 1.013-1.072 for low grip strength), but not on walking pace. We also found that inflammatory bowel disease (IBD) and type 1 diabetes (T1D) were only causally negatively associated with ALM in the discovery stage (OR = 0.986, 95% CI: 0.974-0.999 for IBD; OR = 0.987, 95% CI: 0.975-0.999 for T1D), whereas systemic lupus erythematosus, multiple sclerosis, and overall autoimmune disease were not associated with any of the three sarcopenia-related traits. Additionally, reverse MR analysis only found an association between walking pace and overall autoimmune disease, but this association did not remain in the weighted-median method.

Conclusion

This study demonstrates that RA is causally associated with low grip strength and reduced ALM, and that IBD and T1D may be causally negatively related to ALM.

Sarcopenia and Nutrition in Elderly Rheumatoid Arthritis Patients: A Cross-Sectional Study to Determine Prevalence and Risk Factors

OBJECTIVE

To describe the prevalence of sarcopenia in rheumatoid arthritis (RA) patients aged ≥65 years and identify the risk factors associated with sarcopenia.

METHODS

This is a multicenter, controlled, cross-sectional study of 76 RA patients and 76 age- and sex-matched healthy controls. Sarcopenia was defined according to the revised criteria of the European Working Group on Sarcopenia in Older People (EWGSOP2). Whole-body dual-energy X-ray absorptiometry (DXA) was performed. Binary regression was used to assess the relationship between sarcopenia and sex, age, duration of RA, Mini Nutritional Assessment (MNA) score, and Short Physical Performance Battery (SPPB) score in patients with RA.

RESULTS

Nearly 80% of participants were female, and the average age was >70 years. Patients with RA had lower muscle mass and greater adiposity (fat-to-muscle ratio mean [SD] 0.9 [0.2] vs. 0.8 [0.2]; p = 0.017) than controls, mainly in the central area (android/gynoid ratio, median [p25-p75]: 1.0 [0.9-1.2] vs. 0.9 [0.8-1.1]; p < 0.001). Twelve patients (15.8%) and three controls (3.9%) had confirmed sarcopenia (p = 0.014). Sarcopenic obesity was observed in 8/76 patients with RA (10.5%) and in 1/76 controls (1.3%) (p = 0.016). The factors associated with sarcopenia were male sex (OR [95% CI]: 9.3 [1.1-80.4]; p = 0.042), disease duration (OR [95% CI]: 1.1 [1.0-1.2]; p = 0.012), and nutritional status according to the MNA (OR [95% CI]: 0.7 [0.5-0.9]; p = 0.042).

CONCLUSIONS

Our results suggest that patients with RA aged ≥65 years may be at increased risk for sarcopenia, adiposity, and malnutrition (especially male patients with long-standing disease) and have poor nutritional status.

Quantification of sarcopenia in patients with rheumatoid arthritis by measuring the cross-sectional area of the thigh muscles with magnetic resonance imaging

PURPOSE

To determine the utility of cross-sectional area (CSA) measurements on magnetic resonance imaging (MRI), at the level of the thigh muscles, to estimate muscle mass in discriminating rheumatoid arthritis (RA) patients with sarcopenia from those without.

MATERIALS AND METHODS

Consecutive female RA patients were enrolled for this cross-sectional study. Patients were assessed for disease activity, radiological damage, handgrip strength, physical performance and for the presence of sarcopenia, identified in accordance with the EWGSOP2 criteria. A 1.5 T MRI machine was used to scan the thigh muscles. A dimensional region growth algorithm (Horos™) was used to segment the muscles CSAs (in cm²) on MR images located 25 cm above the knee joint (MRI-CSA-25). The MRI-CSA-25 was obtained by summing the CSAs of the individual muscles. MRI-CSA-25 was correlated (Pearson's r) with the other variables, and its optimal cut-off point (Youden index) for sarcopenia diagnosis was identified in relation to the EWGSOP2 criteria.

RESULTS

32 RA female patients were studied, 34.4% diagnosed as sarcopenic. The mean MRI-CSA-25 was 151.00 cm² for patient with sarcopenia, 275.57 cm² for patient without sarcopenia (p < 0.001). MRI-CSA-25 correlated significantly with measures of physical performance, and disease activity, but not with radiological damage or age. The MRI-CSA-25 optimal cut-off point in discriminating sarcopenic patients was identified at 182.00 cm² (AUC-ROC = 0.894).

CONCLUSION

MRI-CSA-25 can differentiate sarcopenic versus non-sarcopenic RA patients, representing an imaging biomarker of this condition.

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.

Sarcopenia in Rheumatoid arthritis. A narrative review

Sarcopenia was recently identified as an entity in the ICD-10 classification of October 2016. According to the recommendation of the European Working Group on Sarcopenia in Older People (EWGSOP2), sarcopenia is defined as low muscle strength and low muscle mass, while physical performance is used to categorize the severity of sarcopenia. In recent years, sarcopenia has become increasingly common in younger patients with autoimmune diseases such as Rheumatoid arthritis (RA). Due to the chronic inflammation caused by RA, patients have reduced physical activity, immobility, stiffness, and joint destruction and all of that lead to the loss of muscle mass, muscle strength, disability and significantly lowering the patients' quality of life. This article is a narrative review about sarcopenia in RA, with a special focus in its pathogenesis and management.