Rheumatoid sarcopenia: loss of skeletal muscle strength and mass in rheumatoid arthritis

Evaluation of ultrasonographic cartilage and muscle thickness in female rheumatoid arthritis patients with knee pain

BackgroundThis study aimed to show the effect of ultrasonographic muscle and cartilage thickness measurements on knee pain in RA patients.MethodsIn this cross-sectional and single-blind study, female patients aged 30-50 years old, diagnosed with RA, and in remission or low disease activity for at least 6 months were included. They were divided into two groups: with and without knee pain. Knee cartilage thickness measurements from 3 compartments, Quadriceps and Hamstring muscle thickness measurements were performed by ultrasound by a physician blinded to the patients' pain conditions.ResultsOf the 130 patients included in the study; the number of comorbidities in the group with knee pain(n = 61) and glucocorticoid use in the group without knee pain(n = 69) were significantly higher. No significant difference was detected in all cartilage and muscle thickness measurements in the groups with and without knee pain. The average cartilage thickness was found to be significantly lower in patients using glucocorticoids. A low level, positive and significant correlation was detected between cartilage thickness in the medial condyle and age and body mass index(BMI); and between cartilage thickness in the lateral condyle and BMI.ConclusionThere is significant loss of muscle and cartilage thickness in RA patients, even if it is not directly compatible with the pain condition. Being able to evaluate these losses with ultrasound in the follow-up and treatment of the disease is a great power in the hands of the physician.

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.

New research progress of sarcopenia in surgically resectable malignant tumor diseases

With the aging global population, the decline in muscle mass and function among the elderly has emerged as a significant concern. This systemic progressive generalized loss of muscle function and mass is referred to as sarcopenia (SP). In recent years, a growing number of studies have investigated SP, revealing that many tumor diseases, especially in the digestive system, promote its occurrence due to the influence of the disease itself, diet, and other factors. Moreover, SP patients tend to have poorer postoperative recovery. At present, many diagnostic methods have been developed for SP, but no unified standard has been established. Furthermore, the cutoff values of many diagnostic methods for different populations are still in the exploratory stage, and additional clinical studies are required to explore these issues. This article comprehensively and systematically summarizes the diagnostic methods and criteria mentioned in previous research, focusing on the impact of SP on post-surgical patients with various malignant tumors.

Radiological extent predicts prognosis and relapse after acute exacerbation of interstitial lung disease in patients with rheumatoid arthritis: KEIO-RA-cohort

To clarify how the extent of radiological interstitial lung abnormalities impacts the prognosis and risk of relapse in patients with rheumatoid arthritis (RA) following acute exacerbation of interstitial lung disease (AE-ILD). We conducted a retrospective review of all consecutive RA patients from the KEIO-RA cohort who experienced AE-ILD during 2012 to 2024. We investigated the association between the extent of abnormalities on high-resolution computed tomography (HRCT) images, as assessed by Goh's criteria, and outcomes in patients who survived AE-ILD versus those who did not, as well as between patients who survived AE-ILD without relapse and those who experienced relapse. Out of the 34 cases, 10 (29.4%) patients died due to AE-ILD. Of the 26 cases who survived the first AE-ILD event, 8 (30.8%) experienced a relapse, and 2 of them died. Non-survivors had higher Goh's HRCT scores both before and at the time of AE-ILD compared to survivors. Patients who experienced relapse had higher HRCT scores after AE-ILD compared to those who did not relapse. There were no significant differences in treatment regimens for AE-ILD, titers for anti-cyclic citrullinated peptide antibody or rheumatoid factor, or arthritis activity among the groups. Higher HRCT scores both before and at the time of AE-ILD are associated with increased mortality risk, while elevated scores after AE-ILD are linked to a higher likelihood of relapse. These findings highlight the critical role of HRCT assessment in guiding prognosis and post-AE-ILD management in patients with RA.

Belt Electrode-Skeletal Muscle Electrical Stimulation Prevents Muscle Atrophy in the Soleus of Collagen-Induced Arthritis Rats

We investigated the effects of belt electrode-skeletal muscle electrical stimulation (B-SES) on muscle atrophy in collagen-induced arthritis (CIA) rats. Twenty-eight 8-week-old male Dark Agouti rats were immunized with type II collagen and Freund's incomplete adjuvant (day 0). From days 14 to 28, 18 rats received B-SES (50 Hz) four times only on the right hindlimb (STIM), while the contralateral left hindlimb remained unstimulated. Both hindlimbs of 10 untreated CIA rats were defined as controls (CONT). Paw volume was measured every other day. On day 28, the muscle weight, histology, and gene expression of the soleus and extensor digitorum longus (EDL) were analyzed. B-SES did not worsen paw volume throughout the experimental period. Compared with CONT, the muscle weight and fiber cross-sectional area of the soleus were higher in STIM. The expression of muscle degradation markers (atrogin-1 and MuRF-1) in the soleus and EDL was lower in the STIM group than that in the CONT group. In contrast, B-SES did not significantly affect the expression of muscle synthesis (Eif4e and p70S6K) and mitochondrial (PGC-1α) markers. B-SES prevents muscle atrophy in CIA rats by reducing muscle degradation without exacerbating arthritis, demonstrating its promising potential as an intervention for RA-induced muscle atrophy.

The Characteristic of Muscle Function for Sarcopenia in Patients with Rheumatoid Arthritis: A Large-Scale Real-World Cross-Sectional Study

Background and Objectives: Sarcopenia is a notable comorbidity of rheumatoid arthritis (RA), affecting about one third of patients. However, the characteristic of muscle function and its association with RA disease remains unknown. Materials and Methods: This cross-sectional study collected clinical data from a real-world Chinese RA cohort. Sarcopenia was defined as both myopenia and low muscle function (LMF). Myopenia was defined as appendicular skeletal muscle mass index (ASMI) < 7.0 kg/m2 in men and <5.7 kg/m2 in women. LMF was defined as low muscle strength (LMS, hand grip < 28 kg in men and <18 kg in women) or low physical performance (LPP, 6 m gait speed < 1.0 m/s). Results: Among 1125 RA patients recruited in this study, 928 RA patients were eligible for analysis. The prevalence of sarcopenia, myopenia, LMF, LMS, and LPP in all RA patients was 36.5%, 46.1%, 69.0%, 57.8%, and 37.1%, respectively. According to their trends in age and disease activity, there were 111 (11.9%) patients in the young (age < 50 years) and remission (CDAI ≤ 2.8) subgroup, 199 (21.4%) patients in the young and active (CDAI > 2.8) subgroup, 198 (21.3%) patients in the old (age ≥ 50 years) and remission subgroup, and 420 (45.2%) patients in the old and active subgroup. Compared with the two remission subgroups, respectively, the young and active subgroup had significantly lower grip strength, higher prevalence of sarcopenia, LMF, and LMS, and worse activity function. After adjustment for potential confounders, multivariate multinominal logistic regression analysis showed that the young and active subgroup was positively associated with sarcopenia (OR = 3.193, 95%CI: 1.477-6.899), LMF (OR = 2.390, 95%CI: 1.207-4.731), and LMS (OR = 3.520, 95%CI: 1.743-7.110). Conclusions: Worse muscle strength, rather than reduced physical performance, is more common in patients with active RA at a young age. It underscores the critical need for early identification and intervention of muscle dysfunction to improve their quality of life.

Relationship between physical function and sarcopenia in the older adults from Amazonas: A cross-sectional study

BACKGROUND

Physical functioning refers to the ability to perform daily living activities, namely basic activities, instrumental, and advanced activities. Poorer performance in these areas may indicate the potential presence of sarcopenia.

OBJECTIVES

To analyze the differences in physical function between older people with and without sarcopenia and to investigate the associations between physical function tests and sarcopenia.

METHODS

A cross-sectional study based on data from older people from the Northern region of Brazil in the year 2018 was conducted. Study participants included 312 older people aged ≥  60 years (64.1% female). Sarcopenia was defined using the updated criteria of the European Working Group on Sarcopenia in Older People (EWGSOP2). Physical functioning was measured using functional physical fitness tests (30-second chair stand test, chair sit-and-reach test, 8-foot Up-and-Go Test, 6-minute walk test, 4-meter gait speed, and the Fullerton Advanced Balance Scale).

RESULTS

Confirmed sarcopenia was detected in 29.2% of participants, but no participant had severe sarcopenia. Most physical function parameters in the crude analysis were associated with confirmed sarcopenia (all p < 0.05), except for the back scratch test. In a model adjusted for sex, age and body mass index, slower 4-meter gait speed (OR = 1.29, 95%CI = 1.08 to 1.54), slower 8-foot up-and-go test time (OR = 1.32, 95%CI = 1.16 to 1.49), greater chair sit-and-reach test (OR = 0.97, 95%CI = 0.94 to 0.99) and higher self-reported Composite Physical Function scores (OR = 0.94, 95%CI = 0.89 to 0.99) were significantly associated with confirmed sarcopenia status.

CONCLUSIONS

EWGSOP2 confirmed sarcopenia is prevalent in older people residing in Brazil's Northern region and is independently associated with slower walking speed and chair rising ability, reduced trunk and lower-limb flexibility, as well as poorer self-reported physical function.

Practical utilization of sonography for the assessment of muscle diseases in rheumatology

Muscular manifestations are common complaints encountered in daily rheumatology practice. Magnetic resonance imaging and electromyography are employed to evaluate muscular manifestations associated with myositis and other rheumatologic diseases, but both have limitations that hinder their universal applicability. Ultrasound, on the other hand, has been increasingly used given its utility as a point-of-care tool. There is increasing data that show it is a safe and sensitive tool for screening for myositis. Changes in ultrasound images differ between acute and chronic myositis, and echo intensity has been shown to correlate with muscle strength as well as the number of inflammatory cell infiltrates observed in histopathological analysis. Additionally, it can evaluate non-inflammatory muscular conditions, such as muscular dystrophy, sarcopenia, and certain neurologic disorders that mimic myositis. Despite its potential, its use in clinical practice remains limited due to a lack of physician experience and challenges associated with standardizing and optimizing muscle assessment. This review provides updated knowledge on muscle ultrasound as a practical imaging modality for the evaluation of myositis and other rheumatologic diseases. It discusses settings, techniques, and different assessment methods that will aid in its deployment in clinical practice.

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.

Periarticular myositis and muscle fibrosis are cytokine-dependent complications of inflammatory arthritis

The deleterious consequences of chronic synovitis on cartilage, tendon, and bone in rheumatoid arthritis (RA) are well described. In contrast, its effects on periarticular skeletal muscle are under-studied. Furthermore, while TNF inhibition is an effective therapy for RA synovitis, it exacerbates fibrosis in muscle injury models. We aimed to investigate whether myositis and muscle fibrosis are features of inflammatory arthritis and evaluate whether targeted RA therapies influence these disease features. Periarticular muscle was analyzed in murine models of poly- and monoarticular inflammatory arthritis: serum transfer-induced arthritis, collagen-induced arthritis, K/BxN, and antigen-induced arthritis (AIA). Periarticular myositis and an increase in muscle fibroadipocyte progenitors (FAPs) were observed in all models, despite diverse arthritogenic mechanisms. Periarticular muscle fibrosis was observed from day 15 in AIA. Neither etanercept nor baricitinib suppressed periarticular myositis or subsequent fibrosis compared to vehicle, despite reducing arthritis. Notably, etanercept failed to prevent muscle fibrosis even when initiated early, but this was not linked to increased FAP survival or collagen production. Corroborating these data, radiographic and histological analyses revealed periarticular myositis in patients with RA. We conclude that periarticular myositis and fibrosis are under-recognized features of inflammatory arthritis. Targeted RA therapies may not prevent periarticular muscle sequelae, despite controlling arthritis.

Atrophic C2C12 Myotubes Activate Inflammatory Response of Macrophages In Vitro

BACKGROUND

Skeletal muscle wasting is commonly observed in aging, immobility, and chronic diseases. In pathological conditions, the impairment of skeletal muscle and immune system often occurs simultaneously. Recent studies have highlighted the initiative role of skeletal muscle in interactions with immune cells. However, the impact of skeletal muscle wasting on macrophage inflammatory responses remains poorly understood.

METHODS

To investigate the effect of atrophic myotubes on the inflammatory response of macrophages, we established two in vitro models to induce myotube atrophy: one induced by D-galactose and the other by starvation. Conditioned medium (CM) from normal and atrophic myotubes were collected and administered to bone marrow-derived macrophages (BMDMs) from mice. Subsequently, lipopolysaccharide (LPS) stimulation was applied, and the expression of inflammatory cytokines was measured via RT-qPCR.

RESULTS

Both D-galactose and starvation treatments reduced myotube diameter and upregulated muscle atrophy-related gene expression. CM from both atrophic myotubes models augmented the gene expression of pro-inflammatory factors in BMDMs following LPS stimulation, including Il6, Il1b, and Nfkb1. Notably, CM from starvation-induced atrophic myotubes also enhanced Il12b, Tnf, and Nos2 expression in BMDMs after stimulation, a response not observed in D-galactose-induced atrophic myotubes.

CONCLUSIONS

These findings suggest that CM from atrophic myotubes enhanced the expression of LPS-induced pro-inflammatory mediators in macrophages.

Osteoporosis and Rheumatoid Arthritis: Mechanisms Underlying Osteoclast Differentiation and Activation or Factors Associated with Hip Fractures

Osteoporosis is defined as a condition of increased risk of fracture due to decreased bone strength. In developed countries, the number of patients with osteoporosis and fragility fractures has been increasing in recent years due to the growing elderly population, posing a social challenge not only to fracture patients and their families but also to the social healthcare economy. Osteoporosis can be divided into two categories: primary osteoporosis caused by aging or menopause and secondary osteoporosis caused by metabolic or inflammatory diseases or drugs such as glucocorticoids. The majority of patients have primary osteoporosis, and the pathogenesis of postmenopausal osteoporosis and factors associated with fragility fractures in the elderly have been elucidated. On the other hand, rheumatoid arthritis (RA) is one of the causes of secondary osteoporosis. RA is a chronic inflammatory disease characterized by joint swelling and destruction. Most often, treatment focuses on suppressing these symptoms. However, physicians should be aware of the risk of osteoporosis in RA patients, because (1) RA is a chronic inflammatory disease, which itself can be a risk factor for osteoporosis; (2) glucocorticoids, which are sometimes administered to treat RA, can be a risk factor for osteoporosis; and (3) patients with RA are becoming older, and aging is an osteoporosis risk factor. A comprehensive understanding of the pathogenesis of osteoporosis and its fragility fractures requires elucidating the mechanisms underlying osteoclast activation, which drives their development. Furthermore, identifying the factors associated with fragility fractures is essential. This review summarizes the pathogenesis of osteoporosis, the factors associated with fragility fractures, and the associations between RA and osteoporosis development.

Association Between Phase Angle and Tongue Pressure in Older Inpatients with Connective Tissue Diseases

To investigate the association between tongue pressure (TP) and phase angle (PhA) in patients with connective tissue diseases (CTDs) aged 65 years or older. This retrospective cross-sectional study was conducted on 189 patients with CTDs who underwent hospital rehabilitation. TP was measured using a tongue pressure measuring device, and PhA was calculated from the bioimpedance analysis readings. Statistical analyses included multivariate linear regression with TP and receiver operating characteristic curves to determine PhA cutoff values indicative of low TP, defined as < 24.3 kPa for men and < 23.7 kPa for women. A total of 189 patients with CTDs (mean age 75 years; 49 men and 140 women; mean PhA 4.0°; mean TP 27.7 kPa) were included in the analysis. Fifty-five patients had low TP. Patients with low TP had lower PhA values than those with normal TP (mean PhA values 3.5° versus 4.3°). After adjusting for confounding factors, PhA (β = 0.387, p < 0.001) was significantly associated with TP. Cutoff values for PhA predicting low TP were identified as 3.9° for men and 3.5° for women. PhA is associated with TP, independent of other factors, in older inpatients with CTDs. The identified PhA cutoff values could enable the early detection of declining TP.

The impact of uric acid on musculoskeletal diseases: clinical associations and underlying mechanisms

Serum urate (SU) levels are significantly elevated in conditions such as gout, type 2 diabetes (T2D), obesity, and other metabolic syndromes. Recently, due to the high prevalence of hyperuricemia (HUA), numerous clinical connections between SU and musculoskeletal disorders like sarcopenia, osteoarthritis (OA), rheumatoid arthritis (RA), intervertebral disc degeneration (IDD), and osteoporosis (OP) have been identified. This review discusses the mechanisms linking SU to musculoskeletal disorders, as well as the clinical associations of SU with conditions such as sarcopenia, T2D with sarcopenia, McArdle disease, heart failure, gout, OA, IDD, OP and exercise-induced acute kidney injury (EIAKI), offering valuable insights for improved prevention and treatment strategies. Mechanisms linking SU to musculoskeletal disorders include oxidative stress, MSU (monosodium urate) crystal deposition, inflammation, and other factors. In adults, both age and SU levels should be considered for preventing sarcopenia, while gender and SU may directly impact muscle mass in children and adolescents. HUA and gout may be risk factors for OA progression, although some reports suggest otherwise. A U-shaped relationship between SU and IDD has been reported, particularly in Chinese men, indicating lower or higher SU level may be risk factors for IDD. Maintaining SU levels within a certain range may help prevent OP and fractures. Future research, including epidemiological studies and new pathogenesis findings, will further clarify the relationship between musculoskeletal diseases and SU.

USP2 Promotes the Proliferation and Inflammation of Fibroblast-Like Synovial Cells in Rheumatoid Arthritis Through Deubiquitination of TRAF2

Rheumatoid arthritis (RA) is a prevalent inflammatory disorder affecting about 1% of the global population. The ubiquitin-specific protease 2 (USP2) is known to have a substantial influence on the regulation of several cellular processes. Both in vivo (using rats with collagen-induced arthritis, CIA) and in vitro (using human fibroblast-like synoviocytes, HFLS-RA) models of RA were used to examine the role of USP2 in RA. The proliferation of HFLS-RA cells was assessed using the cell counting kit 8 test and EdU staining. The technique used for the assessment of gene expression was quantitative real-time PCR. Protein expression was quantified using Western blot (WB) analysis, while the quantities of inflammatory factors and matrix metalloproteinases were assessed using an ELISA test. The co-immunoprecipitation and ubiquitination tests investigated the relationships between proteins and the underlying molecular pathways. The results of this study demonstrate an upregulation of USP2 expression in both vivo and vitro models of RA. In addition, our findings indicate that the overexpression of USP2 notably exacerbates both proliferation and inflammation. The consistent downregulation of USP2 resulted in a reduction in the secretion of inflammatory cytokines and a suppression of cellular proliferation. Furthermore, it was shown that USP2 interacts with tumor necrosis factor receptor-associated factor 2 (TRAF2) and facilitates the removal of ubiquitination chains from TRAF2, enhancing its stability. Our findings propose that USP2 functions as a favorable modulator of proliferation and inflammatory reactions in HFLS-RA, thereby indicating its potential as a therapeutic target for the treatment of RA.

Molecular mechanisms and potential interventions during aging-associated sarcopenia

Sarcopenia, a common condition observed in the elderly, presenting a significant public health challenge due to its high prevalence, insidious onset and diverse systemic effects. Despite ongoing research, the precise etiology of sarcopenia remains elusive. Aging-related processes, which included inflammation, oxidative stress, compromised mitochondrial function and apoptosis, have been implicated in its development. Notably, effective pharmacological treatments for sarcopenia are currently lacking, highlighting the necessity for a deeper understanding of its pathogenesis and causative factors to enable proactive interventions. This article is aimed to provide an extensive overview of the pathogenesis of sarcopenia, along with a summary of current treatment and prevention strategies.

Disease activity of rheumatoid arthritis and kidney function decline: a large prospective registry study

INTRODUCTION

Chronic kidney disease (CKD) is a common comorbidity of rheumatoid arthritis (RA). The association of longitudinal RA disease activity with long-term kidney function has remained uncertain.

METHOD

We analysed a multicentre prospective RA registry in the USA from 2001 to 2022. The exposure was updated time-averaged Clinical Disease Activity Index (TA-CDAI) categories from study enrolment. The primary outcome was a longitudinal estimated glomerular filtration rate (eGFR) change. Secondary outcomes included developments of CKD stage G3a (eGFR<60 mL/min/1.73 m2) and stage G3b (eGFR<45 mL/min/1.73 m2). Results were adjusted for relevant time-fixed and time-varying covariates.

RESULTS

31 129 patients (median age: 58.0 years, female: 76.3%, median eGFR: 90.7 mL/min/1.73 m2) contributed 234 973 visits and 146 778 person-years of follow-up. Multivariable mixed-effect linear model showed an average annual eGFR decline during follow-up in the TA-CDAI-remission group of -0.83 mL/min/1.73 m2 and estimated additional annual declines (95% CI) of -0.09 (-0.15 to -0.03) in low, -0.17 (-0.23 to -0.10) in moderate and -0.18 (-0.27 to -0.08) mL/min/1.73 m2 in high disease activity patients. Compared with TA-CDAI remission, adjusted HRs (95% CI) for CKD stage G3a during follow-up were 1.15 (1.01 to 1.30) in low, 1.22 (1.06 to 1.40) in moderate and 1.27 (1.05 to 1.52) in high disease activity; for CKD stage G3b, 1.22 (0.84 to 1.76) in low, 1.66 (1.12 to 2.45) in moderate and 1.93 (1.16 to 3.20) in high disease activity.

CONCLUSIONS

Higher RA disease activity was associated with accelerated eGFR decline and increased risk of clinically relevant kidney dysfunction. Future intervention studies should attempt to replicate the association between RA disease activity and eGFR.

Rheumatoid arthritis and the risk of fracture: A Mendelian randomization study

Observational epidemiological studies indicate a higher fracture incidence in rheumatoid arthritis (RA) patients compared to the general population. However, the causal relationship between RA and fracture risk, particularly traumatic and osteoporotic fractures, is not well established. We performed Mendelian randomization (MR) analysis to evaluate the causal relationship between RA and fracture risk. We performed a MR analysis using summary statistics from genome-wide association studies to investigate the causal association between RA and the risk of traumatic fractures at 9 sites and 3 types of osteoporotic fractures. The primary analysis used inverse-variance weighting, supplemented by MR-Egger regression and other methods to assess causal relationships and sensitivity analyses, including heterogeneity and pleiotropy assessments, using R software with appropriate packages. The inverse-variance weighting results demonstrated a causal relationship between genetically predicted RA and an elevated risk of fractures, particularly traumatic fractures of the long bones and osteoporotic fractures, including fractures of shoulder and upper arm (odds ratio [OR] = 1.041, 95% confidence interval [CI]: 1.020-1.062, P = 9.06e-05), fractures of forearm (OR = 1.026, 95% CI: 1.007-1.044, P = .006), fracture of femur (OR = 1.036, 95% CI: 1.009-1.064, P = .009), fractures of lower leg, including joint (OR = 1.031, 95% CI: 1.016-1.047, P = 6.38e-05), fractures of rib(s), sternum, and thoracic vertebrae (OR = 1.041, 95% CI: 1.018-1.064, P = 4.08e-04), osteoporotic with pathological features (OR = 1.128, 95% CI: 1.071-1.188, P = 5.54e-06), postmenopausal osteoporotic with pathological features (OR = 1.060, 95% CI: 1.002-1.123, P = .044), and drug-induced osteoporotic with pathological features (OR = 1.255, 95% CI: 1.124-1.400, P = 5.02e-05). This study highlights the genetic causal link between RA and an increased risk of traumatic and osteoporotic fractures, presenting a new direction for future exploration of the mechanisms underlying RA-related fractures.

Revolutionizing rheumatoid arthritis therapy: harnessing cytomembrane biomimetic nanoparticles for novel treatment strategies

Rheumatoid arthritis (RA) is a systemic immune disease with severe implications for joint health. The issue of non-specific drug distribution potentially limits the therapeutic efficacy and increases the risk associated with RA treatment. Researchers employed cytomembrane-coated biomimetic nanoparticles (NPs) to enhance the targeting delivery efficacy to meet the demand for drug accumulation within the affected joints. Furthermore, distinct cytomembranes offer unique functionalities, such as immune cell activation and augmented NP biocompatibility. In this review, the current strategies of RA treatments were summarized in detail, and then an overview of RA's pathogenesis and the methodologies for producing cytomembrane-coated biomimetic NPs was provided. The application of cytomembrane biomimetic NPs derived from various cell sources in RA therapy is explored, highlighting the distinctive attributes of individual cytomembranes as well as hybrid membrane configurations. Through this comprehensive assessment of cytomembrane biomimetic NPs, we elucidate the prospective applications and challenges in the realm of RA therapy, and the strategy of combined therapy is proposed. In the future, cytomembrane biomimetic NPs have a broad therapeutic prospect for RA.

Factors, mechanisms and improvement methods of muscle strength loss

Muscle strength is a crucial aspect of muscle function, essential for maintaining normal physical activity and quality of life. The global aging population coupled with the increasing prevalence of muscle disorders and strength loss, poses a remarkable public health challenge. Understanding the mechanisms behind muscle strength decline is vital for improving public health outcomes. This review discusses recent research advancements on muscle strength loss from various perspectives, including factors contributing to muscle strength decline, the signaling pathways involved in the deterioration of muscle function, and the methods for assessing muscle strength. The final section explores the influence of exercise stimulation and nutrition on muscle strength.

Understanding the multiple dimensions of ageing: 5Ms for the rheumatologist

The global population is ageing and the rheumatology workforce should be prepared to take care of the inevitable complexities of ageing patients. We can learn from our colleagues and experts in geriatrics about how best to manage multimorbidity, polypharmacy, geriatric syndromes, and shifting priorities of older patients in the context of delivering care for rheumatic diseases. One approach to learning and adopting key ageing constructs within rheumatology practice is to incorporate the established Geriatric 5Ms-principles fundamental to caring for older adults. In this Series paper we discuss the 5Ms in the context of rheumatology practice (1) multicomplexity: assessing and managing multimorbidity and challenging biopsychosocial situations, (2) medications: ensuring that medications do not interfere with the other Ms, (3) mind: managing neurocognitive disorders and comorbid mental health conditions, (4) mobility: ensuring older adults can move independently and safely, and (5) what matters most: aligning care with an older adult's specific goals.

Factors associated with sarcopenia among young adults with juvenile idiopathic arthritis: a cross-sectional study

BACKGROUND

Sarcopenia is a generalized loss of skeletal muscle mass, strength, and performance, and early identification is crucial to minimize adverse outcomes. While sarcopenia is well-studied in older populations, data on its prevalence and risk factors in young adults with juvenile idiopathic arthritis (JIA) remain limited.

OBJECTIVES

The study aimed to evaluate the prevalence of sarcopenia in young adults with JIA and to identify associated risk factors.

METHODS

A cross-sectional single-center study was conducted at the Rheumatology Department of Communal Noncommercial Institution "Oleksandrivska Clinical Hospital", Kyiv, Ukraine, involving 70 patients between November 2020 and November 2022. Initially, 84 patients were recruited; however, 14 were excluded due to joint replacement, diabetes, or refusal to participate. Sarcopenia was diagnosed using the Find-Assess-Confirm-Severity algorithm, assessing muscle strength with a dynamometer, confirming sarcopenia using dual-energy X-ray absorptiometry, and determining severity via gait speed tests. Univariable and multivariable logistic regression was used to identify factors associated with sarcopenia and reported as odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Low handgrip strength, sarcopenia, and severe sarcopenia were observed in 64% (45/70), 59% (41/70), and 34% (24/70) of the patients, respectively. Men were less likely to lose muscle mass than women were (OR 0.29, 95% CI 0.10-0.89; p = 0.03). Sarcopenia was significantly predicted by disease activity according to the Disease Activity Score 28 based on erythrocytes sedimentation rate (DAS28-ESR) and clinical Juvenile Arthritis Disease Activity Score (cJADAS27) (OR 2.08, 95% CI 1.15-3.76; p = 0.01; OR 1.15, 95% CI 1.04-1.27; p = 0.007, respectively), articular and extra-articular Juvenile Arthritis Damage Index (JADI) (JADI-A OR 2.29, 95% CI 1.23-4.25; p = 0.009; JADI-E OR 3.15, 95% CI 1.36-7.29; p = 0.008, respectively), and functional capacity according to the Health Assessment Questionnaire (OR 4.14, 95% CI 1.38-12.5; p = 0.01).

CONCLUSION

Sarcopenia in young adults with JIA was associated with disease activity (measured by DAS28-ESR and cJADAS27), articular and extra-articular damage (measured by JADI indices), and lower functional capacity.

Exploring the Relationship Between Gut Microbiota and Sarcopenia Based on Gut-Muscle Axis

Sarcopenia, as a disease characterized by progressive decline of quality, strength, and function of muscles, has posed an increasingly significant threat to the health of middle-aged and elderly individuals in recent years. With the continuous deepening of studies, the concept of gut-muscle axis has attracted widespread attention worldwide, and the occurrence and development of sarcopenia are believed to be closely related to the composition and functional alterations of gut microbiota. In this review, combined with existing literatures and clinical reports, we have summarized the role and impacts of gut microbiota on the muscle, the relevance between gut microbiota and sarcopenia, potential mechanisms of gut microbiota in the modulation of sarcopenia, potential methods to alleviate sarcopenia by modulating gut microbiota, and relevant advances and perspectives, thus contributing to adding more novel knowledge to this research direction and providing certain reference for future related studies.

Association between phase angle and sarcopenia in patients with connective tissue diseases

BACKGROUND AND AIMS

Early detection and management of sarcopenia in patients with connective tissue diseases (CTDs) are essential. However, the relationship between the phase angle and sarcopenia in patients with CTDs is unknown. This study investigated the association between the phase angle and sarcopenia in patients with (CTDs) and determined the optimal phase angle cutoff values for the early detection of sarcopenia.

METHODS

A retrospective cross-sectional study was conducted in 279 hospitalized patients with CTDs undergoing rehabilitation (median age 73.3 years; 80 men and 199 women). Bioimpedance analysis was used to measure the phase angle, and sarcopenia was assessed according to the Asian Working Group for Sarcopenia criteria.

RESULTS

Sarcopenia was identified in 134 patients (36 men and 98 women). Patients with sarcopenia had a significantly smaller phase angle than those without sarcopenia. Multivariate analysis revealed that phase angle was significantly associated with sarcopenia after adjusting for confounding factors in each sex. The optimal phase angle cutoff value for identifying sarcopenia was 4.6° for men and 4.3° for women, with area under the curve values of 0.795 and 0.754, respectively.

CONCLUSION

Phase angle is a valuable marker for identifying sarcopenia in patients with CTDs. The established phase angle cutoff values of 4.6° in men and 4.3° in women can facilitate the early detection and management of sarcopenia.

The burden, trends, and projections of low back pain attributable to high body mass index globally: an analysis of the global burden of disease study from 1990 to 2021 and projections to 2050

Objective

To systematically evaluate the global burden and trends of low back pain(LBP) associated with high Body Mass Index (BMI) and project future trends up to 2050 using Bayesian Age-Period-Cohort (BAPC) model, providing scientific evidence for prioritizing global preventive actions.

Methods

Utilizing data from the Global Burden of Disease (GBD) 2021 study, this research analyzes the disease burden of low back pain linked to high BMI globally, with Disability-Adjusted Life Years (DALYs) as the primary metric. We examined trends by gender, age, and exposure rate using Estimated Annual Percentage Change (EAPC) and projected future trends with the BAPC model.

Results

In 2021, high BMI-related low back pain accounted for 8,363,759 DALYs, with an age-standardized rate of 97.66 per 100,000 population and an EAPC of 1.14. The DALYs rate varied significantly by country, with the United States, Australia, and Eastern Europe experiencing the highest rates, all exceeding 225 per 100,000 population. The burden has increased globally, with notable rises in China, Southeast Asia, South Asia, and Africa, where EAPCs surpassed 2.5. Regions with medium and high Socio-Demographic Index (SDI) showed the most substantial increases, with the DALY rate in high SDI areas rising from 118.84 to 161.80 per 100,000, and in medium SDI areas from 41.92 to 79.10 per 100,000. Throughout the period from 1990 to 2021, females consistently experienced a higher burden of high BMI-related low back pain than males, with their DALY rate increasing from 92.01 to 126.29 per 100,000. The impact of high BMI on low back pain intensified with age, peaking in the 70-74 age group at 294.13 per 100,000, and then declining to 196.43 per 100,000 in those aged 95 and above. The BAPC model projects that by 2050, the number of DALYs will reach 15,558,278, an increase of 7,806,121 from 2021.

Conclusion

From 1990 to 2021, the global burden of low back pain attributable to high BMI has intensified, particularly affecting females, younger elderly, and developed regions. With increasing global aging and obesity rates, the burden is expected to continue rising rapidly without sustained and effective targeted interventions.

Biologic and targeted synthetic disease-modifying anti-rheumatic drugs improve body composition in rheumatoid arthritis patients more than conventional synthetic disease-modifying anti-rheumatic drugs: Results from the PRESENT study

INTRODUCTION

The effects of biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) and conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) on body composition and muscle function in rheumatoid arthritis (RA) patients requiring treatment enhancement were compared.

METHODS

This multicenter, prospective, observational study (PRESENT Study) divided RA patients non-randomly into a csDMARD group (n = 100) and a b/tsDMARD group (n = 100). Changes in body composition and muscle function were examined in 80 patients in each group followed for 52 weeks. The percentages of new-onset and improved sarcopenia over 1 year were investigated. Patients in the b/tsDMARD group were divided into three groups by drug type: TNF inhibitors (n = 30), non-TNF inhibitors (n = 23), and JAK inhibitors (n = 27).

RESULTS

Baseline median age and disease duration were 70.0 and 4.0 years, respectively. Changes in weight (24 and 52 weeks) and muscle mass (52 weeks) were significantly higher in the b/tsDMARD group (p = .035, p < .001, and p = .002, respectively). On multivariate logistic regression analysis, b/tsDMARD treatment (OR 3.21, p = .002), DAS28-ESR (OR 0.65 p = .011), and muscle mass (OR 0.90, p = .023) were independently associated with increased muscle mass at 52 weeks. The percentages of new-onset and improved sarcopenia were almost equal. There were no significant differences in the time-dependent changes (52 weeks) of clinical status, body composition, muscle function, and status of sarcopenia among TNF inhibitors, non-TNF inhibitors, and JAK inhibitors.

CONCLUSIONS

Weight and muscle mass increased significantly more with b/tsDMARD than with csDMARD treatment. There were no differences in body composition changes by mode of action with b/tsDMARDs.

Risk and predictors of fractures in early rheumatoid arthritis - A long term follow up study of an inception cohort

OBJECTIVES

To examine the risk of fractures in a cohort of patients with newly diagnosed rheumatoid arthritis (RA), compared to the background population, and predictors of fractures detectable early in RA.

METHODS

An inception cohort of patients with RA (N = 233; 164 women/69 men, recruited 1995-2005) was evaluated according to a structured program, including repeated clinical assessments and measures of bone mineral density (BMD), from diagnosis to 10 years later. Matched population controls were identified using the national census register. Fractures through 2019 were identified based on ICD codes. Cox regression models were used to assess the risk of fractures in RA patients compared with controls, and for assessment of potential predictors for fractures in the RA population.

RESULTS

RA patients had an increased risk of fractures (fully adjusted hazard ratio (HR) 1.52, 95 % CI 1.13; 2.06). In the RA cohort, high age, low body mass index, and low BMD were significant baseline predictors of future fractures in multivariate analyses, but baseline RA disease characteristics were not. Worse disability (i.e. higher Health Assessment Questionnaire (HAQ) scores) over time was significantly associated with increased risk of fractures (age-sex-adjusted HR 1.33 per SD, 95 % CI 1.09; 1.63) and there was an inverse association between BMD Z-scores over time and fractures.

CONCLUSION

Patients with RA had higher risk of fractures than controls. Fracture risk was related to BMD at baseline and over time in patients with RA. In addition, worse disability (measured by HAQ) over time was associated with higher risk of fractures.

Sex differences in the association between the muscle quality index and the incidence of depression: A cross-sectional study

BACKGROUND

Depression presents significant challenges to mental health care. Although physical activity is highly beneficial to mental and physical health, relatively few studies have conducted on the relationship between them.

AIM

To investigate the association between muscle quality index (MQI) and incidence of depression.

METHODS

The data used in this cross-sectional study were obtained from the 2011-2014 National Health and Nutritional Examination Survey, which included information on MQI, depression, and confounding factors. Multivariable logistic regression models were employed, while taking into account the complex multi-stage sampling design. A restricted cubic spline model was utilized to investigate the non-linear relationship between the MQI and depression. Additionally, subgroup analyses were performed to identify influential factors.

RESULTS

The prevalence of depression in this population was 8.44%. With the adjusted model, the MQI was associated with depression in females (odds ratio = 0.68, 95% confidence interval: 0.49-0.95) but not in males (odds ratio = 1.08, 95% confidence interval: 0.77-1.52). Restricted cubic spline adjustment of all covariates showed a significant negative non-linear relationship between depression and the MQI in females. The observed trend indicated an 80% decrease in the risk of depression for each unit increase in MQI, until a value of 2.2. Subsequently, when the MQI exceeded 2.2, the prevalence of depression increased by 20% for every unit increase in the MQI. Subgroup analyses further confirmed that the MQI was negatively associated with depression.

CONCLUSION

The MQI was inversely correlated with depression in females but not males, suggesting that females with a higher MQI might decrease the risk of depression.

Mesenchymal Stem Cell-Based Biomimetic Liposome for Targeted Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disorder that severely compromises joint health. The primary therapeutic strategy for advanced RA aims to inhibit joint inflammation. However, the nonspecific distribution of pharmacological agents has limited therapeutic efficacy and heightens the risks associated with RA treatment. To address this issue, we developed mesenchymal stem cell (MSC)-based biomimetic liposomes, termed MSCsome, which were composed of a fusion between MSC membranes and liposomes. MSC some with relatively simple preparation method effectively enhanced the targeting efficiency of drug to diseased joints. Interaction between lymphocyte function-associated antigen-1 and intercellular adhesion molecule-1 enhanced the affinity of the MSCsome for polarized macrophages, thereby improving its targeting capability to affected joints. The effective targeted delivery facilitated drug accumulation in joints, resulting in the significant inhibition of the inflammation, as well as protection and repair of the cartilage. In conclusion, this study introduced MSCsome as a promising approach for the effective treatment of advanced RA, providing a novel perspective on targeted drug delivery therapy for inflammatory diseases.

Melatonin Regulates Rheumatoid Synovial Fibroblasts-Related Inflammation: Implications for Pathological Skeletal Muscle Treatment

Melatonin has been reported to regulate circadian rhythms and have anti-inflammatory characteristics in various inflammatory autoimmune diseases, but its effects in diseases-associated muscle atrophy remain controversial. This study is aimed to determine the evidence of melatonin in rheumatoid arthritis (RA)-related pathological muscle atrophy. We used initially bioinformatics results to show that melatonin regulated significantly the correlation between pro-inflammation and myogenesis in RA synovial fibroblasts (RASF) and myoblasts. The conditioned medium (CM) from melatonin-treated RASF was incubated in myoblasts with growth medium and differentiated medium to investigate the markers of pro-inflammation, atrophy, and myogenesis. We found that melatonin regulated RASF CM-induced pathological muscle pro-inflammation and atrophy in myoblasts and differentiated myocytes through NF-κB signaling pathways. We also showed for the first time that miR-30c-1-3p is negatively regulated by three inflammatory cytokines in human RASF, which is associated with murine-differentiated myocytes. Importantly, oral administration with melatonin in a collagen-induced arthritis (CIA) mouse model also significantly improved arthritic swelling, hind limb grip strength as well as pathological muscle atrophy. In conclusion, our study is the first to demonstrate not only the underlying mechanism whereby melatonin decreases pro-inflammation in RA-induced pathological muscle atrophy but also increases myogenesis in myoblasts and differentiated myocytes.

Low skeletal muscle mass is associated with inferior preoperative and postoperative shoulder function in elderly rotator cuff tear patients

BACKGROUND

The age-related loss of skeletal muscle mass is an important characteristic of sarcopenia, an increasingly recognized condition with systemic implications. However, its association with shoulder function in elderly patients with rotator cuff tears (RCT) remains unknown. This study aimed to investigate the relationship between low skeletal muscle mass and shoulder function in elderly RCT patients.

METHODS

A retrospective analysis was conducted on RCT patients who underwent chest computed tomography (CT) scans for clinical evaluation. Preoperative CT scan images of the chest were used to calculate the cross-sectional area (CSA) of thoracic muscle at the T4 level. The medical records were reviewed. Shoulder function was assessed using the ASES score and CMS score both preoperatively and at the final follow-up. Data on the preoperative range of motion (ROM) for the affected shoulder, were collected for analysis. Subgroup analyses by sex were also performed.

RESULTS

A total of 283 RCT patients, consisting of 95 males and 188 females, with a mean age of 66.22 ± 4.89(range, 60-95 years) years were included in this retrospective study. The low muscle mass group showed significantly higher level of c-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) compared to the normal group(3.75 ± 6.64 mg/L vs. 2.17 ± 2.30 mg/L, p = 0.021; 19.08 ± 12.86 mm/H vs.15.95 ± 10.76 mm/H, p = 0.038; respectively). In the normal group, pre-operative passive ROM, including forward elevation, abduction, lateral rotation, and abductive external rotation, was significantly better than that in the low muscle mass group (127.18 ± 34.87° vs. 89.76 ± 50.61°; 119.83 ± 45.76° vs. 87.16 ± 53.32°; 37.96 ± 28.33° vs. 25.82 ± 27.82°; 47.71 ± 23.56° vs. 30.87 ± 27.76°, all p < 0.01, respectively). Similar results were found in the active ROM of the shoulder. The female low muscle mass group exhibited significantly poorer passive and active ROM (p < 0.05). The post-operative ASES scores and CMS scores of the female low muscle mass group were also statistically worse than those of the female normal group (p < 0.05).

CONCLUSIONS

The results of present study revealed that the low skeletal muscle mass is associated with inferior ROM of the shoulder and per- and post-operative shoulder function, especially for elderly female patients.

Machine Learning-Based Identification of Diagnostic Biomarkers for Korean Male Sarcopenia Through Integrative DNA Methylation and Methylation Risk Score: From the Korean Genomic Epidemiology Study (KoGES)

BACKGROUND

Sarcopenia, characterized by a progressive decline in muscle mass, strength, and function, is primarily attributable to aging. DNA methylation, influenced by both genetic predispositions and environmental exposures, plays a significant role in sarcopenia occurrence. This study employed machine learning (ML) methods to identify differentially methylated probes (DMPs) capable of diagnosing sarcopenia in middle-aged individuals. We also investigated the relationship between muscle strength, muscle mass, age, and sarcopenia risk as reflected in methylation profiles.

METHODS

Data from 509 male participants in the urban cohort of the Korean Genome Epidemiology Study_Health Examinee study were categorized into quartile groups based on the sarcopenia criteria for appendicular skeletal muscle index (ASMI) and handgrip strength (HG). To identify diagnostic biomarkers for sarcopenia, we used recursive feature elimination with cross validation (RFECV), to pinpoint DMPs significantly associated with sarcopenia. An ensemble model, leveraging majority voting, was utilized for evaluation. Furthermore, a methylation risk score (MRS) was calculated, and its correlation with muscle strength, function, and age was assessed using likelihood ratio analysis and multinomial logistic regression.

RESULTS

Participants were classified into two groups based on quartile thresholds: sarcopenia (n = 37) with ASMI and HG in the lowest quartile, and normal ranges (n = 48) in the highest. In total, 238 DMPs were identified and eight probes were selected using RFECV. These DMPs were used to build an ensemble model with robust diagnostic capabilities for sarcopenia, as evidenced by an area under the receiver operating characteristic curve of 0.94. Based on eight probes, the MRS was calculated and then validated by analyzing age, HG, and ASMI among the control group (n = 424). Age was positively correlated with high MRS (coefficient, 1.2494; odds ratio [OR], 3.4882), whereas ASMI and HG were negatively correlated with high MRS (ASMI coefficient, -0.4275; OR, 0.6521; HG coefficient, -0.3116; OR, 0.7323).

CONCLUSION

Overall, this study identified key epigenetic markers of sarcopenia in Korean males and developed a ML model with high diagnostic accuracy for sarcopenia. The MRS also revealed significant correlations between these markers and age, HG, and ASMI. These findings suggest that both diagnostic models and the MRS can play an important role in managing sarcopenia in middle-aged populations.

Osteoporosis and fracture risk are multifactorial in patients with inflammatory rheumatic diseases

Patients with inflammatory rheumatic and musculoskeletal diseases (iRMDs) such as rheumatoid arthritis, connective tissue diseases, vasculitides and spondyloarthropathies are at a higher risk of osteoporosis and fractures than are individuals without iRMDs. Research and management recommendations for osteoporosis in iRMDs often focus on glucocorticoids as the most relevant risk factor, but they largely ignore disease-related and general risk factors. However, the aetiopathogenesis of osteoporosis in iRMDs has many facets, including the negative effects on bone health of local and systemic inflammation owing to disease activity, other iRMD-specific risk factors such as disability or malnutrition (for example, malabsorption in systemic sclerosis), and general risk factors such as older age and hormonal loss resulting from menopause. Moreover, factors that can reduce fracture risk, such as physical activity, healthy nutrition, vitamin D supplementation and adequate treatment of inflammation, are variably present in patients with iRMDs. Evidence relating to general and iRMD-specific protective and risk factors for osteoporosis indicate that the established and very often used term 'glucocorticoid-induced osteoporosis' oversimplifies the complex inter-relationships encountered in patients with iRMDs. Osteoporosis in these patients should instead be described as 'multifactorial'. Consequently, a multimodal approach to the management of osteoporosis is required. This approach should include optimal control of disease activity, minimization of glucocorticoids, anti-osteoporotic drug treatment, advice on physical activity and nutrition, and prevention of falls, as well as the management of other risk and protective factors, thereby improving the bone health of these patients.

Bioinformatics and systems biology approaches to identify potential common pathogeneses for sarcopenia and osteoarthritis

Sarcopenia, a geriatric syndrome characterized by progressive loss of muscle mass and strength, and osteoarthritis, a common degenerative joint disease, are both prevalent in elderly individuals. However, the relationship and molecular mechanisms underlying these two diseases have not been fully elucidated. In this study, we screened microarray data from the Gene Expression Omnibus to identify associations between sarcopenia and osteoarthritis. We employed multiple statistical methods and bioinformatics tools to analyze the shared DEGs (differentially expressed genes). Additionally, we identified 8 hub genes through functional enrichment analysis, protein-protein interaction analysis, transcription factor-gene interaction network analysis, and TF-miRNA coregulatory network analysis. We also discovered potential shared pathways between the two diseases, such as transcriptional misregulation in cancer, the FOXO signalling pathway, and endometrial cancer. Furthermore, based on common DEGs, we found that strophanthidin may be an optimal drug for treating sarcopenia and osteoarthritis, as indicated by the Drug Signatures database. Immune infiltration analysis was also performed on the sarcopenia and osteoarthritis datasets. Finally, receiver operating characteristic (ROC) curves were plotted to verify the reliability of our results. Our findings provide a theoretical foundation for future research on the potential common pathogenesis and molecular mechanisms of sarcopenia and osteoarthritis.

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.

Inflammatory macrophage reprogramming strategy of fucoidan microneedles-mediated ROS-responsive polymers for rheumatoid arthritis

During the pathogenesis of rheumatoid arthritis, inflammatory cells usually infiltrate synovial tissues, notably, M1-type macrophages, whose redox imbalance leads to the degradation of joint structures and deterioration of function. Natural active products play a vital role in immune modulation and antioxidants. In this study, we constructed a ROS-responsive nanoparticle called FTL@SIN, which consists of fucoidan (Fuc) and luteolin (Lut) connected by a ROS-responsive bond, Thioketal (TK), and encapsulated with an anti-rheumatic drug, Sinomenine (SIN), for synergistic anti-inflammatory effects. The FTL@SIN is then dispersed in high molecular weight Fuc-fabricated dissolvable microneedles (FTL@SIN MNs) for local administration. Therapy of FTL@SIN MNs afforded a significant decrease in macrophage inflammation while decreasing key pro-inflammatory cytokines and repolarizing M1 type to M2 type, thereby ameliorating synovial inflammation, and promoting cartilage repair. Additionally, our investigations have revealed that Fucoidan (Fuc) demonstrates synergistic effects, exhibiting superior mechanical strength and enhanced physical stability when compared to microneedles formulated solely with hyaluronic acid. This study combines nanomedicine with traditional Chinese medicine, a novel drug delivery strategy that presents a promising avenue for therapeutic intervention in rheumatoid arthritis.

Prevalence and risk factors of sarcopenia in patients on maintenance hemodialysis: a retrospective cohort study

BACKGROUND

This study aimed to explore the prevalence and related risk factors of sarcopenia in patients on maintenance hemodialysis (MHD).

METHODS

This cohort study enrolled 165 patients on MHD. The patients were divided into sarcopenia and non-sarcopenia groups based on the presence of sarcopenia or not. Sarcopenia was diagnosed according to the consensus of the Asian Sarcopenia Working Group that considers reduced muscle mass and decreased muscle strength (19). The muscle mass was measured using the multi-frequency bioelectrical impedance (Inbody260) and skeletal muscle index (SMI) was used: <7.0 kg/m2 (male); <5.7 kg/m2 (female) - with muscle mass reduction. The electronic grip dynamometer was used for measuring dominant handgrip strength (HGS) to reflect muscle strength. Male patients with HGS < 28 kg and female patients with HGS < 18 kg were considered with a decrease in muscle strength. The demographic characteristics, laboratory indexes, anthropometrical measurements, body compositions, and InBody score were compared between groups. The multivariate logistic regression was used to explore the risk factors for sarcopenia.

RESULTS

Of the 165 patients on MHD, 36 had sarcopenia, and the prevalence was 21.82%. Patients in the sarcopenia group had higher ages and lower body mass index, serum albumin level, circumference of waist, hip, and biceps, handgrip strength, total water content, protein inorganic salt concentrations, skeletal muscle mass, basal metabolic rate, obesity degree, SMI, and body fat content. The multivariate logistic regression showed that age, waist circumference, handgrip strength, and InBody score were influencing factors for sarcopenia in patients on hemodialysis.

CONCLUSION

The prevalence of sarcopenia was high in patients on MHD. Higher age, lower waist circumference, lower handgrip strength, and lower InBody score were independent risk factors for sarcopenia in such patients.

Effects of Low and High Maternal Protein Intake on Fetal Skeletal Muscle miRNAome in Sheep

Prenatal maternal feeding plays an important role in fetal development and has the potential to induce long-lasting epigenetic modifications. MicroRNAs (miRNAs) are non-coding, single-stranded RNAs that serve as one epigenetic mechanism. Though miRNAs have crucial roles in fetal programming, growth, and development, there is limited data regarding the maternal diet and miRNA expression in sheep. Therefore, we analyzed high and low maternal dietary protein for miRNA expression in fetal longissimus dorsi. Pregnant ewes were fed an isoenergetic high-protein (HP, 160-270 g/day), low-protein (LP, 73-112 g/day), or standard-protein diet (SP, 119-198 g/day) during pregnancy. miRNA expression profiles were evaluated using the Affymetrix GeneChip miRNA 4.0 Array. Twelve up-regulated, differentially expressed miRNAs (DE miRNAs) were identified which are targeting 65 genes. The oar-3957-5p miRNA was highly up-regulated in the LP and SP compared to the HP. Previous transcriptome analysis identified that integrin and non-receptor protein tyrosine phosphatase genes targeted by miRNAs were detected in the current experiment. A total of 28 GO terms and 10 pathway-based gene sets were significantly (padj < 0.05) enriched in the target genes. Most genes targeted by the identified miRNAs are involved in immune and muscle disease pathways. Our study demonstrated that dietary protein intake during pregnancy affected fetal skeletal muscle epigenetics via miRNA expression.

Non-Pharmacological Strategies for Managing Sarcopenia in Chronic Diseases

This article focuses on a range of non-pharmacological strategies for managing sarcopenia in chronic diseases, including exercise, dietary supplements, traditional Chinese exercise, intestinal microecology, and rehabilitation therapies for individuals with limited limb movement. By analyzing multiple studies, the article aims to summarize the available evidence to manage sarcopenia in individuals with chronic diseases. The results strongly emphasize the role of resistance training in addressing chronic diseases and secondary sarcopenia. Maintaining the appropriate frequency and intensity of resistance training can help prevent muscle atrophy and effectively reduce inflammation. Although aerobic exercise has limited ability to improve skeletal muscle mass, it does have some positive effects on physical function. Building upon this, the article explores the potential benefits of combined training approaches, highlighting their helpfulness for overall quality of life. Additionally, the article also highlights the importance of dietary supplements in combating muscle atrophy in chronic diseases. It focuses on the importance of protein intake, supplements rich in essential amino acids and omega-3, as well as sufficient vitamin D to prevent muscle atrophy. Combining exercise with dietary supplements appears to be an effective strategy for preventing sarcopenia, although the optimal dosage and type of supplement remain unclear. Furthermore, the article explores the potential benefits of intestinal microecology in sarcopenia. Probiotics, prebiotics, and bacterial products are suggested as new treatment options for sarcopenia. Additionally, emerging therapies such as whole body vibration training, blood flow restriction, and electrical stimulation show promise in treating sarcopenia with limited limb movement. Overall, this article provides valuable insights into non-pharmacological strategies for managing sarcopenia in individuals with chronic diseases. It emphasizes the importance of a holistic and integrated approach that incorporates exercise, nutrition, and multidisciplinary interventions, which have the potential to promote health in the elderly population. Future research should prioritize high-quality randomized controlled trials and utilize wearable devices, smartphone applications, and other advanced surveillance methods to investigate the most effective intervention strategies for sarcopenia associated with different chronic diseases.

The interplay of rheumatoid arthritis and osteoporosis: exploring the pathogenesis and pharmacological approaches

Rheumatoid arthritis (RA) and osteoporosis are two chronic disorders that are often seen together. RA is an autoimmune disorder that causes pain and inflammation in the joints, while osteoporosis is a disorder in which the bones become weak and fragile. Risk factors for bone loss in RA include disease activity, longer disease duration, erosive disease, autoantibody positivity, and joint damage leading to impaired physical activity. Recent research has shown that there is a complex interplay between immune cells, cytokines, and bone remodeling processes in both RA and osteoporosis. The bone remodeling process is regulated by cytokines and immune system signaling pathways, with osteoclasts activated through the RANK/RANKL/OPG pathway and the Wnt/DKK1/sclerostin pathway. Understanding these mechanisms can aid in developing targeted therapies for treatment of osteoporosis in RA patients. Current pharmacological approaches include anti-osteoporotic drugs such as bisphosphonates, denosumab, teriparatide, abaloparatide, raloxifene, and romosozumab. Conventional disease-modifying antirheumatic drugs such as methotrexate and biologicals including TNF inhibitors, IL-6 inhibitors, rituximab, and abatacept lower disease activity in RA and can improve bone metabolism by reducing inflammation but have limited impact on bone mineral density. This review will shed light on the relationship between osteoporosis and rheumatoid arthritis as well as the various factors that influence the onset of osteoporosis in RA patients. We also explore several treatment approaches to effectively managing osteoporosis in RA patients.

Association of systemic inflammatory response index with bone mineral density, osteoporosis, and future fracture risk in elderly hypertensive patients

OBJECTIVES

This study sought to investigate the relationship between the systemic inflammatory response index (SIRI) and bone mineral density (BMD), osteoporosis, and future fracture risk in elderly hypertensive patients.

METHODS

Elderly hypertensive patients (age ≥60 years) who attended our hospital between January 2021 and December 2023 and completed BMD screening were included in the study. Analyses were performed with multivariate logistic and linear regression.

RESULTS

The multiple linear regression indicated that SIRI levels were significantly negatively correlated with lumbar 1 BMD (β = -0.15, 95% CI: -0.24, -0.05), lumbar 2 BMD (β = -0.15, 95% CI: -0.24, -0.05), lumbar 3 BMD (β = -1.35, 95% CI: -0.23, -0.02), lumbar 4 BMD (β = -0.11, 95% CI: -0.30, -0.10), femur neck BMD (β = -0.11, 95% CI: -0.18, -0.05) and Ward's triangle BMD (β = -0.12, 95% CI: -0.20, -0.05) among elderly hypertensive patients, after fully adjusting for confounders. Furthermore, we observed that SIRI was positively associated with future fracture risk in elderly hypertensive patients. Specifically, SIRI was associated with an increased risk of major osteoporotic fractures (β = 0.33) and hip fractures (β = 0.25). The logistic regression analysis indicated that there is an association between the SIRI level and an increased risk of osteoporosis (OR = 1.60, 95% CI = 1.37, 1.87), after fully adjusting for confounders.

CONCLUSIONS

Our findings indicate a potential association between SIRI and BMD, osteoporosis, and the risk of future fractures in elderly hypertensive patients. However, further studies are warranted to confirm these findings.

Population-based epidemiological projections of rheumatoid arthritis in Germany until 2040

OBJECTIVES

Our aim was to conduct a population-based projection to estimate the number of rheumatoid arthritis (RA) cases in Germany until 2040.

METHOD

Data obtained from a report published in 2017 (doi:10.20364/VA-17.08) were used for future prediction analysis. The data were originally collected by the German Central Institute for Statutory Health Insurance. We used the illness-death model to estimate future numbers of RA cases, considering nine possible scenarios based on different incidence and mortality rates.

RESULTS

In the baseline scenario, the number of women with RA is projected to increase by 417 000 cases and men by 179 000 cases by 2040, compared with 2015. Peak numbers of cases are concentrated in the 70-80-year-old age group, particularly among women. In the most favourable scenario (scenario 2), assuming a decreasing incidence, the total number of RA cases is projected to rise by 284 000 by 2040, reflecting a 38% relative increase from 2015 to 2040. The least favourable scenario (scenario 9), assuming an increasing incidence, projects a significant burden on the healthcare system. The total number of RA cases is expected to rise by 1.16 million by 2040, marking a substantial 158% relative increase from 2015 to 2040.

CONCLUSIONS

Our research emphasizes a discernible trend: with an ageing society, improving treatment effectiveness, and declining all-cause mortality, we anticipate a rise in the absolute numbers of RA cases in Germany in the coming years. Our models robustly support this viewpoint, underscoring impending challenges for healthcare systems. Addressing these challenges demands multifaceted interventions.

Causal associations between autoimmune diseases and sarcopenia-related traits: a bi-directional Mendelian randomization study

Background

Sarcopenia is common in patients with autoimmune diseases (ADs); however, the causal associations between ADs and sarcopenia remain unclear. Therefore, this study investigated the causal associations using bi-directional Mendelian randomization analysis.

Methods

Exposure-related single-nucleotide polymorphisms (SNPs) were extracted from genome-wide association studies (GWASs). GWAS statistics for common ADs [Crohn's disease (CD), ulcerative colitis (UC), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis (PSO), and multiple sclerosis (MS)] and sarcopenia-related traits [hand grip strength (HGS), appendicular fat-free mass (FFM), and walking pace] were obtained from public datasets. Inverse-variance weighting as the main method was used to evaluate the causal effect.

Results

Genetically predicted CD had causal effects on whole-body FFM (β = -0.005, p = 0.001), leg FFM (βleft = -0.006, p = 1.8E-4; βright = -0.007, p = 2.0E-4), and arm FFM (βleft = -0.005, p = 0.005; βright = -0.005, p = 0.001), while RA had causal effects on 8 sarcopenia-related traits, namely, HGS (βleft = -2.06, p = 2.8E-38; βright = -2.311, p = 2E-20), whole-body FFM (β = -0.842, p = 4.7E-10), leg FFM (βleft = -0.666, p = 2.6E-6; βright = -0.073, p = 2.1E-3), arm FFM (βleft = -0.63, p = 4.4E-6; βright = -0.736, p = 4.4E-8), and walking pace (β = -1.019, p = 6.2E-14). In the reverse direction, HGS (odds ratio [OR]left = 10.257, p = 3.6E-5; ORright = 16.445, p = 3.7E-7) had causal effects on CD, while HGS (ORleft = 0.994, p = 0.004; ORright = 0.993, p = 1.4E-4), leg FFM (ORleft = 1.003, p = 0.005; ORright = 1.005, p = 1.9E-4), and walking pace (OR = 0.985, p = 5.7E-5) were causally associated with RA. No evidence showed causal associations of UC, SLE, PSO, or MS with sarcopenia-related traits.

Conclusion

Our study demonstrated that the genetic susceptibility to CD and RA was associated with high risk of sarcopenia, and some sarcopenia-related traits had causal effects on CD or RA.

Impact of sarcopenia on the short-term and long-term outcomes of intrahepatic cholangiocarcinoma undergoing hepatectomy: A multi-center study

BACKGROUND

Sarcopenia is associated with adverse prognosis of intrahepatic cholangiocarcinoma (iCCA) after surgery.

METHODS

321 patients with iCCA undergoing surgery were retrospectively recruited and assigned to training and validation cohort. Skeletal muscle index (SMI) was assessed to define sarcopenia. Logistic regression and cox regression analysis were used to identify risk factors. A novel sarcopenia-based nomogram was constructed and validated by ROC curves, calibration curves, and DCA curves.

RESULTS

260 patients were included for analysis. The median age was 63.0 years and 161 patients (61.9%) were diagnosed with sarcopenia. Patients with sarcopenia exhibited a higher rate of postoperative complications, a worse OS and RFS than patients without sarcopenia. Sarcopenia, low albumin and intraoperative blood transfusion were independent risk factors of postoperative complications, while sarcopenia and low albumin were risk factors of high CCI≥26.2. Sarcopenia, high PS score, low-undifferentiated differentiation, perineural invasion, TNM stage III-IV were risk factors of OS, and a novel nomogram based on these five factors was built to predict the 12-, 24-, and 36-months OS, with the mean AUC > 0.6.

CONCLUSION

Sarcopenia is negatively associated with both postoperative complications and survival prognosis of iCCA undergoing hepatectomy.

Accelerated biological aging as a potential risk factor for rheumatoid arthritis

OBJECTS

Previous studies have suggested a potential correlation between rheumatoid arthritis (RA) and biological aging, but the intricate connections and mechanisms remain elusive.

METHODS

In our study, we focused on two specific measures of biological age (PhenoAge and BioAge), which are derived from clinical biomarkers. The residuals of these measures, when compared to chronological age, are defined as biological age accelerations (BAAs). Utilizing the extensive UK Biobank dataset along with various genetic datasets, we conducted a thorough assessment of the relationship between BAAs and RA at both the individual and aggregate levels.

RESULTS

Our observational studies revealed positive correlations between the two BAAs and the risk of developing both RA and seropositive RA. Furthermore, the genetic risk score (GRS) for PhenoAgeAccel was associated with an increased risk of RA and seropositive RA. Linkage disequilibrium score regression (LDSC) analysis further supported these findings, revealing a positive genetic correlation between PhenoAgeAccel and RA. PLACO analysis identified 38 lead pleiotropic single nucleotide polymorphisms linked to 301 genes, providing valuable insights into the potential mechanisms connecting PhenoAgeAccel and RA.

CONCLUSION

In summary, our study has successfully revealed a positive correlation between accelerated biological aging, as measured by BAAs, and the susceptibility to RA.

Advances in sarcopenia: mechanisms, therapeutic targets, and intervention strategies

Sarcopenia is a multifactorial condition characterized by loss of muscle mass. It poses significant health risks in older adults worldwide. Both pharmacological and non-pharmacological approaches are reported to address this disease. Certain dietary patterns, such as adequate energy intake and essential amino acids, have shown positive outcomes in preserving muscle function. Various medications, including myostatin inhibitors, growth hormones, and activin type II receptor inhibitors, have been evaluated for their effectiveness in managing sarcopenia. However, it is important to consider the variable efficacy and potential side effects associated with these treatments. There are currently no drugs approved by the Food and Drug Administration for sarcopenia. The ongoing research aims to develop more effective strategies in the future. Our review of research on disease mechanisms and drug development will be a valuable contribution to future research endeavors.

Geriatric nutrition risk index: a more powerful index identifying muscle mass loss in patients with rheumatoid arthritis

OBJECTIVE

To explore the association of geriatric nutrition risk index (GNRI), a traditional albumin-body weight calculation, with myopenia in patients with rheumatoid arthritis (RA) and compare its ability to identify myopenia with protein indicators.

METHODS

This cross-sectional study was carried out based on a Chinese RA cohort. Clinical data and protein indicators (including albumin, globulin, albumin to globulin ratio, prealbumin, hemoglobin) were collected. GNRI was estimated by serum albumin and body weight. Myopenia was indicated as muscle mass loss measured by bioelectric impedance analysis.

RESULTS

There were 789 RA patients included with mean age 52.6 ± 12.6 years and 77.6% female. There were 41.3%, 18.0%, 27.5%, 13.2% patients with no (GNRI > 98), low (GNRI 92 to ≤ 98), moderate (GNRI 82 to < 92), and major nutrition-related risk (GNRI < 82). There were 406 (51.5%) RA patients with myopenia, RA patients with major nutrition-related risk had the highest prevalence of myopenia (87.5% vs. 73.3% vs. 50.0% vs. 26.1%). Multivariate logistic analysis showed that compared with no risk, RA patients with low (OR = 3.23, 95% CI: 1.86-5.61), moderate (OR = 9.56, 95% CI: 5.70-16.01), and major nutrition-related risk (OR = 28.91, 95% CI: 13.54-61.71) were associated with higher prevalence of myopenia. Receiver operating characteristic curves showed that GNRI (AUC = 0.79) performed a better identifiable ability toward myopenia than serum albumin (AUC = 0.66) or others indicators (AUC range 0.59 to 0.65), respectively.

CONCLUSION

GNRI, an objective and convenient albumin-weight index, may be preferable for identifying myopenia in RA patients. Key Points • We firstly elucidated the association of GNRI with muscle mass loss among RA patients, and compared its ability to identify muscle mass loss with serum albumin or other protein indicators. • Major nutrition-related risk identified by GNRI showed the highest risk of muscle mass loss, GNRI demonstrated a greater ability to identify myopenia in RA patients. which indicated GNRI was an objective and convenient albumin-weight index to identify myopenia in RA patients.

The prevalence of sarcopenia in spondyloarthritis patients: a meta-analysis

BACKGROUND

Spondyloarthritis (SpA) is a chronic inflammatory disorder that affects sacroiliac joints and spine, resulting in substantial disability. Sarcopenia, characterized by the loss of muscle mass and function, is a prevalent comorbidity in various chronic diseases. However, the exact prevalence of sarcopenia in SpA patients remains uncertain. The objective of this study is to conduct a systematic review and meta-analysis of the available literature to determine the prevalence of sarcopenia in SpA.

METHODS

A comprehensive search was conducted in EMBASE, MEDLINE, WEB OF SCIENCE, and COCHRANE databases to identify relevant studies published up to 2023. Studies investigating the prevalence of sarcopenia in SpA patients were included. Data on study characteristics, participant demographics, diagnostic criteria for sarcopenia, and prevalence rates were extracted. Meta-analysis was performed using a random-effects model to estimate the overall prevalence of sarcopenia in SpA patients.

RESULTS

A total of 16 studies that met the inclusion criteria were included in the systematic review. These studies encompassed a combined sample size of 999 patients with SpA. The meta-analysis findings revealed that the overall prevalence of sarcopenia in SpA patients was 25.0% (95% confidence interval: 0.127 to 0.352). Furthermore, the prevalence of presarcopenia and severe sarcopenia was found to be 21.0% and 8.7%, respectively. Subgroup analysis was conducted to examine different diagnostic criteria, subtypes, and sex of SpA in relation to sarcopenia.

CONCLUSION

This systematic review and meta-analysis provide a comprehensive overview of the prevalence of sarcopenia in SpA patients. The findings suggest a high prevalence of sarcopenia in SpA patients, emphasizing the need for targeted interventions to prevent and manage sarcopenia. And further research is needed to explore the underlying mechanisms and potential therapeutic strategies for sarcopenia in SpA.

Association between skeletal muscle and left ventricular mass in patients with hyperthyroidism

Objective

This study aims to investigate the relationship between skeletal muscle and left ventricular mass (LVM) in patients with hyperthyroidism, providing theoretical and data-based foundations for further research on the interaction between secondary muscle atrophy and cardiac remodeling.

Methods

A retrospective data collection was conducted, including 136 patients with hyperthyroidism (Study group) and 50 healthy participants (control group). The Study group was further divided into Group A (high LVM) and Group B (low LVM) based on LVM size. Multiple linear regression analysis was performed to examine the correlation between skeletal muscle and LVM, with model evaluation. Based on the results, further nonlinear regression analysis was conducted to explore the detailed relationship between skeletal muscle and LVM.

Results

Compared to the control group, the Study group exhibited significantly lower LVM, skeletal muscle mass index (SMI), and skeletal muscle mass (SMM) (P<0.05). Within the subgroups, Group A had significantly higher SMI, SMM, and hand grip strength compared to Group B (P<0.05). The results of the multiple linear regression showed a certain correlation between SMI (β=0.60, P=0.042, 95% CI=0.02~1.17) and hand grip strength (β=0.34, P=0.045, 95% CI=0.01~0.67) with LVM. However, the residuals of the multiple regression did not follow a normal distribution (K-S=2.50, P<0.01). Further results from a generalized linear model and structural equation modeling regression also demonstrated a correlation between SMI (β=0.60, P=0.040, 95% CI=0.03~1.17) (β=0.60, P=0.042, 95% CI=0.02~1.17) and hand grip strength (β=0.34, P=0.043, 95% CI=0.01~0.67) (β=0.34, P=0.045, 95% CI=0.01~0.67) with LVM.

Conclusion

Patients with hyperthyroidism may exhibit simultaneous decreases in LVM, SMM, and SMI. The LVM in patients is correlated with SMM and hand grip strength, highlighting the need for further exploration of the causal relationship and underlying mechanisms. These findings provide a basis for the prevention and treatment of secondary sarcopenia and cardiac pathology in patients with hyperthyroidism.

Isoliquiritigenin inhibits apoptosis and ameliorates oxidative stress in rheumatoid arthritis chondrocytes through the Nrf2/HO-1-mediated pathway

Rheumatoid arthritis (RA) is a chronic inflammatory condition known for its irreversible destructive impact on the joints. Chondrocytes play a pivotal role in the production and maintenance of the cartilage matrix. However, the presence of inflammatory cytokines can hinder chondrocyte proliferation and promote apoptosis. Isoliquiritigenin (ISL), a flavonoid, potentially exerts protective effects against various inflammatory diseases. However, its specific role in regulating the nuclear factor E2-associated factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in chondrocytes in RA remains unclear. To investigate this, this study used human chondrocytes and Sprague-Dawley rats to construct in vitro and in vivo RA models, respectively. The study findings reveal that cytokines markedly induced oxidative stress, the activation of matrix metalloproteinases, and apoptosis both in vitro and in vivo. Notably, ISL treatment significantly mitigated these effects. Moreover, Nrf2 or HO-1 inhibitors reversed the protective effects of ISL, attenuated the expression of Nrf2/HO-1 and peroxisome proliferator-activated receptor gamma-coactivator-1α, and promoted chondrocyte apoptosis. This finding indicates that ISL primarily targets the Nrf2/HO-1 pathway in RA chondrocytes. Moreover, ISL treatment led to improved behavior scores, reduced paw thickness, and mitigated joint damage as well as ameliorated oxidative stress in skeletal muscles in an RA rat model. In conclusion, this study highlights the pivotal role of the Nrf2/HO-1 pathway in the protective effects of ISL and demonstrates the potential of ISL as a treatment option for RA.