Muscle density in rheumatoid arthritis: associations with disease features and functional outcomes

Exploring complex links: inflammatory rheumatic diseases and men's health

This article examines the complex interactions between inflammatory rheumatic diseases (IRDs) and men's health. It delves into the effects of IRDs on reproductive health, erectile dysfunction, prostate involvement, male osteoporosis, body composition, physical activity, and coping mechanisms. The findings show that the prevalence of sexual dysfunction varies among different diseases, underscoring the necessity for comprehensive counseling. The link between IRDs and prostate health, with a substantial rise in benign prostatic hyperplasia among IRD patients, demonstrates the condition's importance. In contrast to popular belief, osteoporosis mostly affects women; the current study highlights the growing identification of male osteoporosis, particularly in the setting of IRDs. Male RA patients had a significant loss in bone mineral density, highlighting the importance of increasing awareness and tailored therapy to address osteoporosis in men. IRDs affect body composition, with male RA patients showing imbalances characterized by decreased lean body mass and increased fat mass. Given the dynamic nature of these conditions, coping with IRDs necessitates thorough and individualized diversified approaches. The complex link between IRDs and men's health demands continuing research, including longitudinal studies and tailored therapies. The essay promotes a patient-centered approach, recognizing the unique obstacles that males with IRDs confront.

Is Immune Thrombocytopenia and its Treatment Associated with Sarcopenia?

BACKGROUND

Immune thrombocytopenia (ITP) is defined as an isolated platelet count less than 100 × 109/L in the absence of other causes of thrombocytopenia. Sarcopenia is a body-wide muscular disorder with a progressive nature that leads to reduced mobility, physical disability, falls, and poor quality of life. We aimed to evaluate the frequency of objectively diagnosed sarcopenia in patients with ITP and to determine whether ITP therapies have sarcopenic effects.

METHODS

This prospective study included patients who were followed up with ITP in the hematology outpatient clinic. Patients who had received corticosteroids within 3 months were excluded. The handgrip strength test, appendicular skeletal muscle mass (ASMM), ASMM/height2 value, soft lean mass (SLM), trunk soft lean mass (SLMT), and the 6-min walking speed test were applied for muscular evaluations and physical performance assessment.

RESULTS

We included 53 patients (female/male: 73.58%/26.42%). While sarcopenia was not observed in 77.36% of ITP patients, possible sarcopenia was diagnosed in 9.43% and confirmed sarcopenia in 13.21%. Severe sarcopenia was not seen in any of the patients. Loss of muscle strength was observed in 22.64% of patients. SLM was found to be low in 92.45%.

CONCLUSION

Sarcopenia may be more frequent among patients with ITP compared to the population, and it is important to note that 92.45% of patients had low SLM and 54.72% had low SLMT. Eltrombopag therapy might be beneficial as demonstrated by higher SLM, ASMM, and ASMM/height2 values.

Docosahexaenoic acid and etanercept could reduce functional and metabolic alterations during collagen-induced arthritis in rats without any synergistic effect

AIMS

Rheumatoid arthritis is an autoimmune disease which induces chronic inflammation and increases the risk for sarcopenia and metabolic abnormalities. Nutritional strategies using omega 3 polyunsaturated fatty acids could be proposed to alleviate inflammation and improve the maintenance of lean mass. Independently, pharmacological agents targeting key molecular regulators of the pathology such as TNF alpha could be proposed, but multiple therapies are frequently necessary increasing the risk for toxicity and adverse effects. The aim of the present study was to explore if the combination of an anti-TNF therapy (Etanercept) with dietary supplementation with omega 3 PUFA could prevent pain and metabolic effects of RA.

MATERIALS AND METHODS

RA was induced using collagen-induced arthritis (CIA) in rats to explore of supplementation with docosahexaenoic acid, treatment with etanercept or their association could alleviate symptoms of RA (pain, dysmobility), sarcopenia and metabolic alterations.

KEY FINDINGS

We observed that Etanercept had major benefits on pain and RA scoring index. However, DHA could reduce the impact on body composition and metabolic alterations.

SIGNIFICANCE

This study revealed for the first time that nutritional supplementation with omega 3 fatty acid could reduce some symptoms of rheumatoid arthritis and be an effective preventive treatment in patients who do not need pharmacological therapy, but no sign of synergy with an anti-TNF agent was observed.

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

Sarcopenia, a disorder that involves the generalized loss of skeletal muscle strength and mass, was formally recognized as a disease by its inclusion in the International Classification of Diseases in 2016. Sarcopenia typically affects older people, but younger individuals with chronic disease are also at risk. The risk of sarcopenia is high (with a prevalence of ≥25%) in individuals with rheumatoid arthritis (RA), and this rheumatoid sarcopenia is associated with increased likelihood of falls, fractures and physical disability, in addition to the burden of joint inflammation and damage. Chronic inflammation mediated by cytokines such as TNF, IL-6 and IFNγ contributes to aberrant muscle homeostasis (for instance, by exacerbating muscle protein breakdown), and results from transcriptomic studies have identified dysfunction of muscle stem cells and metabolism in RA. Progressive resistance exercise is an effective therapy for rheumatoid sarcopenia but it can be challenging or unsuitable for some individuals. The unmet need for anti-sarcopenia pharmacotherapies is great, both for people with RA and for otherwise healthy older adults.

The Hypertriglyceridemic Waist Phenotype Is Associated with Several Cardiovascular Risk Factors in Women with Rheumatoid Arthritis

Rheumatoid arthritis (RA) associates with cardiovascular risk factors (CVRF) such as dyslipidemias and systemic inflammation. Cardiovascular Disease (CVD) is the leading cause of mortality. The hypertriglyceridemic waist phenotype (HTWP) identifies increased CVRF; however, information about HTWP on RA is scarce.

OBJECTIVE

To evaluate the association of HTWP with CVRF in RA.

MATERIAL AND METHODS

Cross-sectional study. Women (125) with RA were included (ACR, 1987). Anthropometry, bioimpedance, body mass index (BMI), disease activity score 28 (DAS28), and health assessment questionnaire disability index (HAQ-Di) were determined. The lipid profile determination includes the atherogenic index (AI) (TC/HDL) and Framingham Risk Score. HTWP is defined as a waist circumference ≥88 cm and triglycerides ≥ 150 mg/dL. Chi-squared and Student's t-tests were applied for comparisons.

RESULTS

HTWP was found in 38 (30.4%) patients. The subgroup with HTWP had a greater frequency of arterial hypertension (AHT) (57.9 vs. 37.9, p = 0.04), Type 2 DM (23.7 vs. 8.0, p= 0.02), BMI (29.7 ± 3.2, vs. 26.8 ± 4.3, p < 0.001), fat mass (39.3 ± 4.8 vs. 34.7 ± 6.8, p < 0.001), and AI (4.7 ± 1.2 vs. 3.7 ± 1.0, p < 0.001). No differences between DAS28 and HAQ-Di were found. HTWP was associated with the presence of MetS and CVR (p < 0.001 and p = 0.012, respectively).

CONCLUSION

The HTWP in RA is associated with CVRF, and its potential predictive role should be evaluated in longitudinal studies.

Ultrasound and magnetic resonance imaging as diagnostic tools for sarcopenia in immune-mediated rheumatic diseases (IMRDs)

Sarcopenia is characterized by loss of muscle mass, altered muscle composition, fat and fibrous tissue infiltration, and abnormal innervation, especially in older individuals with immune-mediated rheumatic diseases (IMRDs). Several techniques for measuring muscle mass, strength, and performance have emerged in recent decades. The portable dynamometer and gait speed represent the most frequently used tools for the evaluation of muscle strength and physical efficiency, respectively. Aside from dual-energy, X-ray, absorptiometry, and bioelectrical impedance analysis, ultrasound (US) and magnetic resonance imaging (MRI) techniques appear to have a potential role in evaluating muscle mass and composition. US and MRI have been shown to accurately identify sarcopenic biomarkers such as inflammation (edema), fatty infiltration (myosteatosis), alterations in muscle fibers, and muscular atrophy in patients with IMRDs. US is a low-cost, easy-to-use, and safe imaging method for assessing muscle mass, quality, architecture, and biomechanical function. This review summarizes the evidence for using US and MRI to assess sarcopenia.

Gait rehabilitation for foot and ankle impairments in early rheumatoid arthritis: a feasibility study of a new gait rehabilitation programme (GREAT Strides)

Background

Foot impairments in early rheumatoid arthritis are common and lead to progressive deterioration of lower limb function. A gait rehabilitation programme underpinned by psychological techniques to improve adherence, may preserve gait and lower limb function. This study evaluated the feasibility of a novel gait rehabilitation intervention (GREAT Strides) and a future trial.

Methods

This was a mixed methods feasibility study with embedded qualitative components. People with early (< 2 years) rheumatoid arthritis (RA) and foot pain were eligible. Intervention acceptability was evaluated using a questionnaire. Adherence was evaluated using the Exercise Adherence Rating Scale (EARS). Safety was monitored using case report forms. Participants and therapists were interviewed to explore intervention acceptability. Deductive thematic analysis was applied using the Theoretical Framework of Acceptability. For fidelity, audio recordings of interventions sessions were assessed using the Motivational Interviewing Treatment Integrity (MITI) scale. Measurement properties of four candidate primary outcomes, rates of recruitment, attrition, and data completeness were evaluated.

Results

Thirty-five participants (68.6% female) with median age (inter-quartile range [IQR]) 60.1 [49.4–68.4] years and disease duration 9.1 [4.0–16.2] months), were recruited and 23 (65.7%) completed 12-week follow-up. Intervention acceptability was excellent; 21/23 were confident that it could help and would recommend it; 22/23 indicated it made sense to them. Adherence was good, with a median [IQR] EARS score of 17/24 [12.5–22.5]. One serious adverse event that was unrelated to the study was reported. Twelve participants’ and 9 therapists’ interviews confirmed intervention acceptability, identified perceptions of benefit, but also highlighted some barriers to completion. Mean MITI scores for relational (4.38) and technical (4.19) aspects of motivational interviewing demonstrated good fidelity. The Foot Function Index disability subscale performed best in terms of theoretical consistency and was deemed most practical.

Conclusion

GREAT Strides was viewed as acceptable by patients and therapists, and we observed high intervention fidelity, good patient adherence, and no safety concerns. A future trial to test the additional benefit of GREAT Strides to usual care will benefit from amended eligibility criteria, refinement of the intervention and strategies to ensure higher follow-up rates. The Foot Function Index disability subscale was identified as the primary outcome for the future trial.

Trial registration

ISRCTN14277030

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-01061-9.

Sarcopenia in rheumatic disorders: what the radiologist and rheumatologist should know

Sarcopenia is defined as the loss of muscle mass, strength, and function. Increasing evidence shows that sarcopenia is common in patients with rheumatic disorders. Although sarcopenia can be diagnosed using bioelectrical impedance analysis or DXA, increasingly it is diagnosed using CT, MRI, and ultrasound. In rheumatic patients, CT and MRI allow "opportunistic" measurement of body composition, including surrogate markers of sarcopenia, from studies obtained during routine patient care. Recognition of sarcopenia is important in rheumatic patients because sarcopenia can be associated with disease progression and poor outcomes. This article reviews how opportunistic evaluation of sarcopenia in rheumatic patients can be accomplished and potentially contribute to improved patient care.

Tissue engineered skeletal muscle model of rheumatoid arthritis using human primary skeletal muscle cells

Rheumatoid arthritis (RA) is a chronic inflammatory disease primarily targeting the joints. Autoreactive immune cells involved in RA affect other tissues, including skeletal muscle. Patients with RA experience diminished physical function, limited mobility, reduced muscle function, chronic pain, and increased mortality. To explore the impact of RA on skeletal muscle, we engineered electrically responsive, contractile human skeletal muscle constructs (myobundles) using primary skeletal muscle cells isolated from the vastus lateralis muscle of 11 RA patients (aged 57-74) and 10 aged healthy donors (aged 55-76), as well as from the hamstring muscle of six young healthy donors (less than 18 years of age) as a benchmark. Since all patients were receiving treatment for the disease, RA disease activity was mild. In 2D culture, RA myoblast purity, growth rate, and senescence were not statistically different than aged controls; however, RA myoblast purity showed greater variance compared to controls. Surprisingly, in 3D culture, contractile force production by RA myobundles was greater compared to aged controls. In support of this finding, assessment of RA myofiber maturation showed increased area of sarcomeric α-actinin (SAA) expression over time compared to aged controls. Furthermore, a linear regression test indicated a positive correlation between SAA protein levels and tetanus force production in RA and controls. Our findings suggest that medications prescribed to RA patients may maintain-or even enhance-muscle function, and this effect is retained and observed in in vitro culture. Future studies regarding the effects of RA therapeutics on RA skeletal muscle, in vivo and in vitro, are warranted.

Interaction effect of systemic inflammation and modifiable rheumatoid cachexia risk factors on resting energy expenditure in patients with rheumatoid arthritis

Background

In rheumatoid cachexia (RC), high resting energy expenditure (REE) is associated with loss of muscle mass driven by proinflammatory cytokines. The objectives of this study were to investigate parameters associated with RC, and the interaction between systemic inflammation and modifiable risk factors for RC on REE.

Methods

Thirty-five rheumatoid arthritis (RA) and nineteen non-RA controls comparable in age, sex, race and BMI underwent measures of REE by indirect calorimetry. Clinical, dietary, body composition and physical function data were collected. Homeostasis model assessment for insulin resistance (HOMA-IR) and serum interleukin-6 (IL-6) were used as parameters of IR and systemic inflammation, respectively. Regression models tested association between REE and dependent variables, including pre-specified interaction tests involving HOMA-IR and IL-6 and dietary intake of protein per weight (PPW) and IL-6.

Results

RA subjects were mostly women (94%) and had a median age of 54 years (50.5, 70) and BMI of 30.5 kg/m2 (26.1, 36.9). We observed a significant interaction effect between PPW and serum IL-6 on REE among RA subjects in the multiple regression model among RA. The upper tertile of PPW demonstrated a significant negative correlation between REE and IL-6 (β=-19.97, 95% CI [-35.41, -4.54], p=0.01). The lower tertile of PPW demonstrated a significant positive correlation between REE and IL-6 (β=42.24, 95% CI [4.25, 80.23], p=0.03).

Conclusions

While IR can lead to muscle catabolism, IR was not significantly associated with REE in RA individuals. Higher dietary protein intake could attenuate the effect of systemic inflammation on REE in RA patients.

Prevalence and risk factors of moderate to severe hepatic steatosis in patients with rheumatoid arthritis: an ultrasonography cross-sectional case-control study

Background:

The independent association between hepatic steatosis and rheumatoid arthritis is poorly defined.

Methods:

The presence of moderate to severe steatosis was assessed, using liver ultrasonography, in 364 consecutive non-diabetic subjects (223 patients with rheumatoid arthritis and 141 age- and sex-matched healthy controls). Adjusted multiple regression analysis was performed to explore the association between rheumatoid arthritis and moderate to severe steatosis in the overall sample and identify independent risk factors in the rheumatoid arthritis subgroup.

Results:

The prevalence of moderate to severe steatosis in the overall sample was 31.3%, with a significantly higher prevalence in patients with rheumatoid arthritis than healthy controls (38.7% versus 19.7%, p < 0.0001). After adjustment for sex, age, cholesterol, triglycerides, body mass index, waist, hypertension and smoke, rheumatoid arthritis remained significantly associated with moderate to severe steatosis [odds ratio (95% confidence interval) = 2.24 (1.31, 3.84); p = 0.003]. In the rheumatoid arthritis group, male sex, higher body mass index, higher triglycerides concentrations and higher cumulative dosage of methotrexate [odds ratio (95% confidence interval) = 1.11 (1.01, 1.23); p = 0.026] were significantly associated with moderate to severe steatosis, while systemic inflammation, disease activity, use of steroids and biologics were not.

Conclusion:

Rheumatoid arthritis is independently associated with moderate to severe steatosis, with male sex, higher body mass index and cumulative dose of methotrexate being predisposing factors. Further prospective studies are warranted to confirm our findings and to investigate the effect of steatosis on liver outcomes in the rheumatoid arthritis population.

Prevalence of Sarcopenia and its Association with Antirheumatic Drugs in Middle-Aged and Older Adults with Rheumatoid Arthritis: A Systematic Review and Meta-analysis

To examine the prevalence of sarcopenia and its association with antirheumatic drugs in adults with rheumatoid arthritis (RA). This review was registered on PROSPERO and followed PRISMA guidelines. Electronic databases were searched for studies reporting on the prevalence of sarcopenia in adults with RA using any muscle index (muscle mass, strength and/or physical performance) and cutpoints as recommended by established criteria (EWGSOP1/2, AWGS, FNIH, SDOC). The secondary objective was to investigate the relationship between RA, antirheumatic drugs, and sarcopenia. Among 2240 middle-aged and older adults with RA (mean age: 47.7 ± 5.5 to 75.0 ± 6.2 years, 83.8% women), the pooled prevalence of low muscle mass/sarcopenia was 30.2% [95% confidence interval (CI) 24.2-36.2%; 16 studies; I²: 89.2%]. Sub-group analysis showed a non-significant higher prevalence of low muscle mass alone (32.6%, 95% CI 25.0-40.3%; I²: 87.9%) versus consensus definitions of sarcopenia (25.4%, 95% CI 15.4-35.3%; I²: 91.2%, p = 0.255). In adults with RA, corticosteroid use was positively associated with sarcopenia [odds ratio (OR) 1.46, 95% CI 0.94-2.29, 7 studies; I²: 47.5%] while conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) was inversely associated (OR 0.70, 95% CI 0.52-0.94; 6 studies: I²: 0.00%) with this muscle disease. No association was found for biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) (OR 0.83, 95% CI 0.54-1.30; 6 studies: I²: 47.6%). Sarcopenia is a common comorbidity of RA, and as such, clinicians should screen for this muscle disease in adults with RA. Further longitudinal studies are needed to understand the role of antirheumatic drugs (particularly type, dosing, and duration) in the development of sarcopenia.

Peripheral Volumetric Muscle Area and Total Body Volume in Postmenopausal Women With Rheumatoid Arthritis

The effect of rheumatoid arthritis (RA) on peripheral muscle parameters is not completely understood. This study aimed to elucidate the influence of RA on peripheral muscle area and whole body skeletal muscle mass index (SMI) using peripheral quantitative computed tomography and dual-energy X-ray absorptiometry in postmenopausal women. This cross-sectional study included 54 postmenopausal women with RA and 86 healthy controls. Peripheral quantitative computed tomography and dual-energy X-ray absorptiometry were used to measure the muscle cross-sectional area and skeletal muscle mass. Muscle strength was assessed using a handheld dynamometer. Additionally, the effects of RA on muscle area and density as well as the bone / muscle area ratio were analyzed using multivariate models. The muscle area index of the thigh and forearm were correlated between both groups (RA: r = 0.357, p = 0.030; and healthy controls: r = 0.608, p < 0.001) and each index correlated with SMI in RA and healthy controls (p < 0.001). Bone / muscle area ratio correlated between forearms and thighs in health controls only (r = 0.547, p < 0.001). The RA group had a decreased thigh muscle area (p = 0.014); the fat area and fat muscle area ratio at the thigh and forearm were significantly increased (all p < 0.001), as well as thigh bone / muscle area ratio (p = 0.015). The RA group also had significantly lower forearm muscle density (p < 0.001). A sensitivity analysis excluding those on bisphosphonates led to similar results. Independent of RA, the thigh and forearm muscle area correlate with each other and with SMI. Differences in the bone / muscle ratio between RA and healthy controls may indicate regional muscle effects of inflammation and inactivity.

Contribution of Intramyocellular Lipids to Decreased Computed Tomography Muscle Density With Age

Skeletal muscle density, as determined by computed tomography (CT), has been shown to decline with age, resulting in increased frailty and morbidity. However, the mechanism underlying this decrease in muscle density remains elusive. We sought to investigate the role of intramyocellular lipid (IMCL) accumulation in the age-related decline in muscle density. Muscle density was measured using computerized tomography (CT), and IMCL content was quantified using in vivo proton magnetic resonance spectroscopy (¹H-MRS). The study population consisted of 314 healthy participants (142 men, 32–98 years) of the Baltimore Longitudinal Study of Aging (BLSA). In addition to IMCL quantification, obesity-related covariates were measured, including body mass index (BMI), waist circumference, and circulating triglyceride concentration. Higher IMCL concentrations were significantly correlated with lower muscle density in older individuals, independent of age, sex, race, and the obesity-associated covariates (p < 0.01). Lower muscle density was also significantly associated with greater age-adjusted IMCL, a variable we constructed using LOESS regression (p < 0.05). Our results suggest that the accumulation of IMCL may be associated with a decrease in muscle density. This may serve to define a potential therapeutic target for treatment of age-associated decreased muscle function.

Prevalence of Sarcopenia and its Association with Antirheumatic Drugs in Middle-Aged and Older Adults with Rheumatoid Arthritis: A Systematic Review and Meta-analysis

To examine the prevalence of sarcopenia and its association with antirheumatic drugs in adults with rheumatoid arthritis (RA). This review was registered on PROSPERO and followed PRISMA guidelines. Electronic databases were searched for studies reporting on the prevalence of sarcopenia in adults with RA using any muscle index (muscle mass, strength and/or physical performance) and cutpoints as recommended by established criteria (EWGSOP1/2, AWGS, FNIH, SDOC). The secondary objective was to investigate the relationship between RA, antirheumatic drugs, and sarcopenia. Among 2240 middle-aged and older adults with RA (mean age: 47.7 ± 5.5 to 75.0 ± 6.2 years, 83.8% women), the pooled prevalence of low muscle mass/sarcopenia was 30.2% [95% confidence interval (CI) 24.2-36.2%; 16 studies; I²: 89.2%]. Sub-group analysis showed a non-significant higher prevalence of low muscle mass alone (32.6%, 95% CI 25.0-40.3%; I²: 87.9%) versus consensus definitions of sarcopenia (25.4%, 95% CI 15.4-35.3%; I²: 91.2%, p = 0.255). In adults with RA, corticosteroid use was positively associated with sarcopenia [odds ratio (OR) 1.46, 95% CI 0.94-2.29, 7 studies; I²: 47.5%] while conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) was inversely associated (OR 0.70, 95% CI 0.52-0.94; 6 studies: I²: 0.00%) with this muscle disease. No association was found for biological/targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) (OR 0.83, 95% CI 0.54-1.30; 6 studies: I²: 47.6%). Sarcopenia is a common comorbidity of RA, and as such, clinicians should screen for this muscle disease in adults with RA. Further longitudinal studies are needed to understand the role of antirheumatic drugs (particularly type, dosing, and duration) in the development of sarcopenia.

Analysis of the Associations between Arthritis and Fall Histories in Korean Adults

(1) Background: the purpose of the present study was to analyze the associations between arthritis and fall histories in Korean adults. (2) Methods: data from the 2015 and 2017 Korean Community Health Survey were analyzed. In total, 322,962 participants aged ≥40 years were included. The participants were divided into two different groups. First, the participants were divided into the ‘arthritis (osteoarthritis or rheumatoid arthritis) for entire life’ and ‘nonarthritis for entire life (comparison I)’ groups. Subsequently, the participants were divided into the ‘current arthritis’ and ‘noncurrent arthritis (comparison II)’ groups. Afterwards, we analyzed the prevalence odds ratios (pORs) of the fall histories of the participants using a logistic regression analysis with the 95% confidence interval (CI). The variables of income, education level, region of residence, smoking status, alcohol consumption, obesity, subjective health status, stress level, physical activity, and sleep hours were adjusted for as covariates. (3) Results: both the arthritis for entire life and current arthritis groups had higher prevalence rates of falls than the comparison I and comparison II groups, respectively (each p < 0.001). The pORs of falling ≥1 time and ≥2 times per year in the arthritis for the entire life group were 1.42 (95% CI = 1.38–1.46) and 1.69 (95% CI = 1.62–1.76), respectively. The adjusted pORs for falling ≥1 time and ≥2 times per year in the current arthritis group were 1.35 (95% CI = 1.31–1.39) and 1.56 (95% CI = 1.50–1.63), respectively. (4) Conclusions: previous arthritis has a significant impact on the risk of falling.

The toxic effects of chloroquine and hydroxychloroquine on skeletal muscle: a systematic review and meta-analysis

The aim of this systematic review was to perform qualitative and quantitative analysis on the toxic effects of chloroquine (CQ) and hydroxychloroquine (HCQ) on skeletal muscles. We designed the study according to PRISMA guidelines. Studies for qualitative and quantitative analyses were selected according to the following inclusion criteria: English language; size of sample (> 5 patients), adult (> age of 18) patients, treated with CQ/HCQ for inflammatory diseases, and presenting and not presenting with toxic effects on skeletal muscles. We collected data published from 1990 to April 2020 using PubMed, Cochrane Library, EMBASE, and SciELO. Risk of bias for observational studies was assessed regarding the ROBIN-I scale. Studies with less than five patients (case reports) were selected for an additional qualitative analysis. We used the software Comprehensive Meta-Analysis at the confidence level of 0.05. We identified 23 studies for qualitative analysis (17 case-reports), and five studies were eligible for quantitative analysis. From case reports, 21 patients presented muscle weakness and confirmatory biopsy for CQ/HCQ induced myopathy. From observational studies, 37 patients out of 1,367 patients from five studies presented muscle weakness related to the use of CQ/HCQ, and 252 patients presented elevated levels of muscle enzymes (aldolase, creatine phosphokinase, and lactate dehydrogenase). Four studies presented data on 34 patients with confirmatory biopsy for drug-induced myopathy. No study presented randomized samples. The chronic use of CQ/HCQ may be a risk for drug-induced myopathy. There is substantiated need for proper randomized trials and controlled prospective studies needed to assess the clinical and subclinical stages of CQ/HCQ -induced muscle myopathy.

Association of Low Muscle Density With Deteriorations in Muscle Strength and Physical Functioning in Rheumatoid Arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is associated with low muscle density due to the accumulation of intramuscular fat. The present study was undertaken to identify predictors of changes in muscle density and to determine whether low muscle density predicted changes in strength and physical function.

METHODS

Patients with RA, ages 18-70 years, completed whole-body dual-energy x-ray absorptiometry and peripheral quantitative computed tomography to quantify lean and fat mass indices and muscle density. Dynamometry was used to measure strength at the hand, knee, and lower leg. Disability and physical function were measured with the Health Assessment Questionnaire (HAQ) and the Short Physical Performance Battery (SPPB). Assessments were performed at baseline and at follow-up. Regression analyses assessed associations between patient characteristics, muscle density, and deteriorations in strength and function.

RESULTS

Muscle density was assessed at baseline in 107 patients with RA. Seventy-nine of these patients (74%) returned for a follow-up assessment at a median follow-up time of 2.71 years (interquartile range 2.35-3.57). Factors associated with declines in muscle density included female sex, higher disease activity, smoking, and lower insulin-like growth factor 1 (IGF-1) levels. Greater muscle density Z score at baseline (per 1 SD) was associated with less worsening per year according to HAQ, SPPB, and 4-meter walk time scores and a lower risk of a clinically important worsening in HAQ score (odds ratio [OR] 1.90 [95% confidence interval (95% CI) 1.06, 3.42]; P = 0.03) and walking speed (OR 2.87 [95% CI 1.05, 7.89]; P = 0.04).

CONCLUSION

Worsening of skeletal muscle density occurred in patients with higher disease activity, in smokers, and in those with lower IGF-1. Low muscle density was associated with worsening of physical function. Interventions addressing reductions in muscle quality might prevent functional decline.

Team Rehabilitation in Inflammatory Arthritis Benefits Functional Outcomes Along With Improved Body Composition Associated With Improved Cardiorespiratory Fitness

OBJECTIVE

We investigated the effect of team rehabilitation in inflammatory arthritis (IA) on body composition and physical function. Further, we examined whether body composition and physical function are associated with disability and cardiorespiratory fitness (CRF).

METHODS

The participants were 149 patients (74% women) with chronic arthritis, a mean age of 53 (SD 13) years, and mean disease duration of 21 (SD 13) years. They participated in a 4-week team rehabilitation program and were evaluated at prerehabilitation, and at 3 and 12 months postrehabilitation. Body composition was assessed by bioelectrical impedance analysis and CRF by the Åstrand 6-minute cycle test. ANCOVA with Bonferroni correction and linear mixed models were applied.

RESULTS

After 3 and 12 months, there were significant reductions in waist circumference and measures of fat, adjusted for age, sex, and baseline measures. The prevalence of adiposity and central obesity decreased after 12 months. Hand grip strength and timed sit-to-stand (TST) improved together with reduction in Health Assessment Questionnaire (HAQ) and increased VO₂max after 3 and 12 months. HAQ reduction over time was associated with prerehabilitation measures of lean mass of legs, hand grip strength, TST, and physical activity, and changes in hand grip strength, physical activity, and sedentary time, but not with changes of body composition. VO₂max improvement over time was associated with prerehabilitation BMI, waist circumference, measures of fat and lean mass, changes in BMI, waist circumference, and measures of fat.

CONCLUSION

In patients with IA, 4-week team rehabilitation benefited body composition, level of physical functioning, activity, and CRF for up to 12 months. Measures of physical function and activity were linked to HAQ over time, whereas body composition was linked to CRF.

Association of body composition with disease activity and disability in rheumatoid arthritis

BACKGROUND/AIMS

To explore the associations between body composition and pain, disease activity, and disability in rheumatoid arthritis (RA).

METHODS

The study enrolled 335 patients with RA and underwent body composition measurement with an InBody analyzer. The associations of body mass index (BMI), body fat mass, and skeletal muscle mass with disease activity score in 28 joints (DAS28), an index derived to measure the subjective component of DAS28 (DAS28-P), a pain visual analogue scale (VAS), and disability measured with the health assessment questionnaire (HAQ) were explored. Obesity was defined as BMI ≥ 25 kg/m2.

RESULTS

The median (interquartile range) disease duration was 6 years (3.5 to 9) and the mean DAS28 score was 3.6 ± 1.1. The mean BMI was 23.6 ± 3.6 kg/m2 and 109 patients (32.5%) were obese. Compared with non-obese patients, obese patients had a higher C-reactive protein (1.68 mg/dL vs. < 0.1 mg/dL, p = 0.013), higher pain VAS score (40 vs. 35, p = 0.031), and higher DAS28-erythrocyte sedimentation rate score (3.75 ± 1.18 vs. 3.46 ± 1.11, p = 0.031). In multivariate regression analysis, the DAS28 score in females was positively associated with the current steroid dose, body fat mass, and HAQ score, while the HAQ score in females was associated with older age, DAS28, lower skeletal muscle mass, and higher body fat/skeletal muscle ratio. In the multivariate regression analysis, the DAS28-P score in females was positively associated with body fat/skeletal muscle ratio and HAQ.

CONCLUSION

Body composition, such as the body fat mass and body fat/skeletal muscle ratio, is significantly associated with disease activity and disability in female RA patients.

Circulating Fibroblast Growth Factor-21 Levels in Rheumatoid Arthritis: Associations With Disease Characteristics, Body Composition, and Physical Functioning

OBJECTIVE

This study evaluated associations between fibroblast growth factor (FGF)-21, an adipokine associated with metabolic stress, and adverse longitudinal changes in body composition and physical functioning in patients with rheumatoid arthritis (RA).

METHODS

At baseline and follow-up, patients with RA aged 18-70 years completed whole-body dual-energy X-ray absorptiometry and peripheral quantitative computed tomography to quantify lean mass, fat mass, and muscle density. Dynamometry assessed muscle strength at the hand and knee, and physical functioning was measured with the Health Assessment Questionnaire (HAQ) and the Short Physical Performance Battery (SPPB). FGF-21 and inflammatory cytokines were measured at baseline. Linear and logistic regression analyses assessed associations between FGF-21 levels and both body composition and physical functioning over time.

RESULTS

There were 113 patients with RA enrolled, and 84 (74%) returned for follow-up at a median of 2.68 years. At baseline, FGF-21 was associated with age, smoking, methotrexate use, adiposity, and inflammatory cytokines: tumor necrosis factor receptor type I, YKL-40, vascular endothelial growth factor (VEGF), and resistin. The highest FGF-21 quartile was associated with worse SPPB and HAQ. Higher baseline FGF-21 levels (per 1 SD) were associated with worsening in muscle density and area Z-scores (β -0.06, 95% CI -0.12 to 0.008, P = 0.08; and β -0.05, 95% CI -0.10 to 0.006, P = 0.08, respectively) and a greater probability of a clinically meaningful worsening of HAQ (OR 2.37, 95% CI 1.21-4.64, P = 0.01). The fourth FGF-21 quartile was associated with worsening of SPPB (β -0.57, 95% CI -1.04 to -0.09, P = 0.02).

CONCLUSION

FGF-21 levels are associated with obesity and inflammatory cytokines, and with worsening in physical functioning in RA. These data support the hypothesis that FGF-21 can identify patients at risk of functional decline.

The relationship between weight status and metabolic syndrome in patients with rheumatoid arthritis and spondyloarthritis

OBJECTIVES

To compare the prevalence and correlates of metabolic syndrome (MetS) stratified by body mass index (BMI) categories in rheumatoid arthritis (RA) and spondyloarthritis (SpA).

METHODS

The age- and sex-standardized prevalence of MetS was calculated by BMI categories and compared between RA and SpA patients before starting first biologic, and controls. The determinants of metabolic syndrome in patients without obesity were investigated.

RESULTS

MetS was observed in 28% of RA (21/75), 22.5% of SpA (18/80), 19% of controls (187/998). The age- and sex-standardized prevalence of MetS was not significantly different between RA 19% (95% CI: 11-27%), SpA 26% (95% CI: 16-36%) and controls 16% (95% CI: 14-18%). When stratified by BMI, the standardized prevalence of MetS was less frequent in obese RA patients (15%, 95% CI: 4-27%) compared to obese controls (48%, 95% CI: 40-55%) or to obese SpA (36%, 95% CI: 26-45%). In normal-weight RA patients, MetS standardized prevalence was 16% (95% CI: 7-25%) compared to 5% (95% CI: 0-11%) in SpA, and 6% (95% CI: 4-8%) in controls. In non-obese SpA, MetS was associated with abdominal obesity, visceral fat mass and cardiovascular risk. In non-obese RA patients with metabolic syndrome, body composition did not differ from metabolically healthy RA patients.

CONCLUSIONS

MetS is not uniform among patients with similar BMI. In RA, MetS was less frequent in obese patients, and unlike SpA, was not associated with body fat composition in non-obese patients. Differences between RA and SpA for metabolic health suggest various pathophysiological mechanisms.

Frailty syndrome in rheumatoid arthritis and symptomatic osteoarthritis: an emerging concept in rheumatology

Musculoskeletal conditions such as rheumatoid arthritis (RA) and symptomatic osteoarthritis (OA) were the leading cause of disability in developed countries and disproportionately affects older adults. Frailty is an emerging concept in rheumatology, which represents an important construct to aid in the identification of in- dividuals who are vulnerable to adverse events and less favourable outcomes. The prevalence of frailty among the community-dwelling population increases with age: it ranges from 7% to 10% in those aged over 65 years and to 20-40% among octogenarians. Among patients with RA, the prevalence of frailty is comparable to, or even greater, that of older geriatric cohorts and pre-frailty, a condition including a major health vulnerability between robust and frail, is much more prevalent in RA than in geriatric cohorts. Clinical OA is also associated with frailty and pre-frailty in older adults in European countries. The overall prevalence of clinical OA at any site was 30.4%; frailty was present in 10.2% and pre-frailty in 51.0 %. The diagnosis of frailty is usually clinical and based on specific criteria, which are sometimes inconsistent. Therefore, there is an increasing need to identify and vali- date robust biomarkers for this condition. In the literature, different criteria have been validated to identify frail older subjects, which mainly refer to two conceptual models: the Physical Frailty (PF) phenotype proposed by Fried and the cumulative deficit approach proposed by Rockwood. The purpose of this review was to quantita- tively synthesize published literature on the prevalence of frailty in RA and OA and summarize current evidence on the validity and practicality of the most commonly used screening tools for frailty.

Characteristics of Appendicular Tissue Components in Patients with Rheumatoid Arthritis

Background

The purpose of this study was to identify the characteristics of appendicular lean mass (ALM) associated with rheumatoid arthritis (RA) and to analyze appendicular tissue components in patients with RA.

Methods

We prospectively reviewed of patients with RA who underwent dual energy X-ray absorptiometry in a single center. From data of 28 patients, ALM was calculated. Regression analysis was used to investigate the association between ALM and RA. Using propensity score matching, patients with RA were compared to the control group from 18,698 patients of Korea National Health and Nutrition Examination Surveys data. RA and control group were matched in a 1: 5, respectively.

Results

In regression model, there was significantly negative association between disease activity score and ALM index in patients with RA in unadjusted (β=−0.387, 95% confidence interval [CI], −0.729 to −0.045) and model adjusted for age, sex, and body mass index (β=−0.227, 95% CI, −0.451 to −0.003). In matching with age and sex, the arms fat mass and fat fraction of RA group were significantly lower than that of control group. In matching with age, sex, and body mass index, the ALM index and legs lean mass of RA group were significantly higher than control group.

Conclusions

Patients with RA have a lower ALM with higher disease activity. In addition, we found that patients with RA had different tissue component in arms and legs compared to general population.

Could Omega 3 Fatty Acids Preserve Muscle Health in Rheumatoid Arthritis?

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by a high prevalence of death due to cardiometabolic diseases. As observed during the aging process, several comorbidities, such as cardiovascular disorders (CVD), insulin resistance, metabolic syndrome and sarcopenia, are frequently associated to RA. These abnormalities could be closely linked to alterations in lipid metabolism. Indeed, RA patients exhibit a lipid paradox, defined by reduced levels of total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol whereas the CVD risk is increased. Moreover, the accumulation of toxic lipid mediators (i.e., lipotoxicity) in skeletal muscles can induce mitochondrial dysfunctions and insulin resistance, which are both crucial determinants of CVD and sarcopenia. The prevention or reversion of these biological perturbations in RA patients could contribute to the maintenance of muscle health and thus be protective against the increased risk for cardiometabolic diseases, dysmobility and mortality. Yet, several studies have shown that omega 3 fatty acids (FA) could prevent the development of RA, improve muscle metabolism and limit muscle atrophy in obese and insulin-resistant subjects. Thereby, dietary supplementation with omega 3 FA should be a promising strategy to counteract muscle lipotoxicity and for the prevention of comorbidities in RA patients.

Glucocorticoid use is an independent risk factor for developing sarcopenia in patients with rheumatoid arthritis: from the CHIKARA study

INTRODUCTION

Patients with rheumatoid arthritis (RA) are at higher risk of sarcopenia because of joint dysfunction and chronic inflammation. The present study aimed to investigate the predictors or risk factors for developing sarcopenia in RA patients using the prospective observational CHIKARA database. We hypothesized that older age, higher disease activity, lower physical function, and glucocorticoid (GC) use are risk factors for sarcopenia.

METHODS

A total of 100 consecutive RA patients participated in the CHIKARA study. Their body compositions were examined using a body composition analyzer. Laboratory data, disease activity, physical function, and treatment were investigated. Sarcopenia was assessed at baseline and at 1 year. Predictors or risk factors for sarcopenia development at 1 year were investigated by univariate and multivariate analyses.

RESULTS

Of 68 patients without sarcopenia at baseline, 9 (13.4%) developed sarcopenia over the year. Univariate analysis showed that age (r = 0.28, p = 0.022), average GC dose over the year (r = 0.25, p = 0.043), and body mass index (r = - 0.28, p = 0.019) were significantly associated with the development of sarcopenia. Average GC use at ≥ 3.25 mg/day was a significant factor on multivariate analysis (odds ratio 8.81, 95% confidence interval 1.14-67.9, p = 0.037).

CONCLUSIONS

RA patients using GCs at an average dose ≥ 3.25 mg/day over 1 year were at higher risk for developing sarcopenia. Reduction or withdrawal of GCs may prevent sarcopenia.Key Points• Patients with RA are at higher risk of sarcopenia.• Predictors or risk factors for developing sarcopenia over 1 year in RA patients were investigated using the prospective observational CHIKARA database.• RA patients using GCs at an average dose ≥ 3.25 mg/day over 1 year were at higher risk for developing sarcopenia.• Reduction or withdrawal of GCs may be essential to prevent sarcopenia.

Lipid accumulation and mitochondrial abnormalities are associated with fiber atrophy in the skeletal muscle of rats with collagen-induced arthritis

Rheumatoid arthritis (RA) has a negative impact on muscle mass, and reduces patient's mobility and autonomy. Furthermore, RA is associated with metabolic comorbidities, notably in lipid homeostasis by unknown mechanisms. To understand the links between the loss in muscle mass and the metabolic abnormalities, arthritis was induced in male Sprague Dawley rats (n = 11) using the collagen-induced arthritis model. Rats immunized with bovine type II collagen were compared to a control group of animals (n = 11) injected with acetic acid and complete Freund's adjuvant. The clinical severity of the ensuing arthritis was evaluated weekly by a semi-quantitative score. Skeletal muscles from the hind limb were used for the histological analysis and exploration of mitochondrial activity, lipid accumulation, metabolism and regenerative capacities. A significant atrophy in tibialis anterior muscle fibers was observed in the arthritic rats despite a non-significant decrease in the weight of the muscles. Despite moderate inflammation, accumulation of triglycerides (P < 0.05), reduced mitochondrial DNA copy number (P < 0.05) and non-significant dysfunction in mitochondrial cytochrome c oxidase activity were found in the gastrocnemius muscle. Concomitantly, our results suggested an activation of the muscle specific E3 ubiquitin ligases MuRF-1 and MAFbx. Finally, the adipose tissue from the arthritic rats exhibited decreased PPARγ mRNA suggesting reduced adipogenic capacities. In conclusion, the reduced adipose tissue adipogenic capacity and skeletal muscle mitochondrial capacity are probably involved in the activation of protein catabolism, inhibition of myogenesis, accumulation of lipids and fiber atrophy in the skeletal muscle during RA.

Factors Associated With Low Lean Mass in Early Rheumatoid Arthritis: A Cross- Sectional Study

Background and Objectives: The aim of the study was to evaluate body composition (BC) of rheumatoid arthritis (RA) patients at disease onset compared to population controls focusing on the associations between low lean mass and disease specific parameters, nutritional factors and physical activity. Materials and Methods: 91 patients with early rheumatoid arthritis (ERA) (72% female) and 328 control subjects (54% female) were studied. BC- lean and fat mass parameters were measured with a Lunar Prodigy Dual Energy X-Ray Absorptiometry (DXA) machine. The prevalence, age and gender adjusted odds ratios of having low lean mass and overfat, associations between nutrition, physical activity, and ERA disease specific parameters and the presence of low lean mass were evaluated. Results: We found that the BC of patients with recent onset RA differs from control subjects-ERA patients had a higher mean body fat percentage (BFP) and lower appendicular lean mass (ALM). 41.8% of the ERA patients and 19.8% of the controls were classified as having low lean mass adjusted OR 3.3 (95% C.I. 1.9-5.5, p < 0.001). 68.1% of the ERA subjects and 47.3% of the controls were overfat (adjusted OR 1.9 (95% C.I. 1.1-3.3, p = 0.02)) and the adjusted odds of having both low lean mass and overfat were 4.4 times higher (26.4% vs. 7.0% 95% C.I. 2.3-8.4, p < 0.001) among the ERA group. Higher ESR (OR 1.03, C.I.1.002-1.051, p = 0.03), CRP (OR 1.03, C.I. 1.002-1.061, p = 0.04), lower protein intake (OR 0.98 C.I. 0.96-0.99, p = 0.04), corticosteroid usage (OR 3.71 C.I. 1.4-9.9, p < 0.01) and lower quality of life (higher HAQ score OR 2.41 C.I. 1.24-4.65, p < 0.01) were associated with having low lean mass in the ERA group (adjusted to age and gender). Conclusions: Patients with early RA have lower appendicular lean mass and higher body fat percentage compared to healthy controls. Loss of lean mass in early RA is associated with elevated inflammatory markers inducing catabolism, lower protein intake and also with GCS treatment.

Skeletal muscle fat in individuals with rheumatoid arthritis compared to healthy adults

OBJECTIVE

To compare skeletal muscle fat (SMF), intermuscular adipose tissue (IMAT) and subcutaneous adipose tissue (SAT) between individuals with rheumatoid arthritis (RA), and healthy individuals of the same age, and healthy individuals at least 10 years older than those with RA.

METHODS

Two cross-sectional studies. In the first study, RA subjects were matched by age, sex, and BMI with healthy adults. In the second, RA subjects were matched by sex and BMI to adults 10-20 years older. SMF, IMAT and SAT were measured with Computed Tomography images of the mid-thigh region. We used parametric or non-parametric related-sample tests to compare fat accumulation between RA subjects and healthy adults.

RESULTS

In the first study SMF was significantly higher in the RA cohort compared to their age-matched healthy counterparts (mean difference = -3.5 HU (95% -6.2, -0.9), p = 0.011), but IMAT and SAT were similar between cohorts. In the second study, SMF, IMAT and SAT were not significantly different between the RA and matched older healthy cohorts. In both studies, there were no significant differences in mid-thigh muscle area between RA subjects and healthy adults.

CONCLUSION

SMF accumulation in RA was higher than in healthy individuals of similar age, sex, BMI. Accumulation of fat within and around the muscles in RA was not different compared to the matched healthy older individuals, indicating that muscle fat accumulation in RA might mimic a pattern not different from healthy aging.

Computed tomography-derived area and density of pectoralis muscle associated disease severity and longitudinal changes in chronic obstructive pulmonary disease: a case control study

BACKGROUND

Muscle wasting is associated with prognosis in patients with chronic obstructive pulmonary disease (COPD). The cross-sectional area of skeletal muscles on computed tomography (CT) could serve as a method to evaluate body composition. The present study aimed to determine the ability of CT-derived pectoralis muscle area (PMA) and pectoralis muscle density (PMD) to determine the severity of COPD and change in longitudinal pulmonary function in patients with COPD.

METHODS

A total of 293 participants were enrolled in this study, a whom 222 had undergone at least two spirometry measurements within 3 years after baseline data acquisition. PMA and PMD were measured from a single axial slice of chest CT above the aortic arch at baseline. The emphysema index and bronchial wall thickness were quantitatively assessed in all scans. The generalized linear model was used to determine the correlation between PMA and PMD measurements and pulmonary function.

RESULTS

PMA and PMD were significantly associated with baseline lung function and the severity of emphysema (P < 0.05). Patients with the lowest PMA and PMD exhibited significantly more severe airflow obstruction (β = - 0.06; 95% confidence interval: - 0.09 to - 0.03]. PMA was statistically associated with COPD assessment test (CAT) score (P = 0.033). However, PMD did not exhibit statistically significant correlation with either CAT scores or modified Medical Research Council scores (P > 0.05). Furthermore, neither PMA nor PMD were associated with changes in forced expiratory volume in 1 s over a 3-year periods.

CONCLUSIONS

CT-derived features of the pectoralis muscle may be helpful in predicting disease severity in patients with COPD, but are not necessarily associated with longitudinal changes in lung function.

Dose-Response Relationship Between Neuromuscular Electrical Stimulation and Muscle Function in People With Rheumatoid Arthritis

BACKGROUND

Neuromuscular electrical stimulation (NMES) is a viable intervention for improving impaired muscle function in individuals with rheumatoid arthritis (RA). However, there is limited evidence about the dose-response relationship between NMES and muscle function in these individuals.

OBJECTIVE

The objectives of this study were to investigate the dose-response relationship between NMES and muscle function in individuals with RA and to establish the minimal NMES training intensity for promoting improvements.

DESIGN

This study was a secondary analysis of data obtained before and after an NMES intervention in a randomized study.

METHODS

The study took place at a research clinic. Only adults diagnosed with RA were included. The intervention consisted of 36 NMES treatment sessions for the quadriceps muscles over 16 weeks. Muscle function was measured before and after the intervention; quadriceps cross-sectional area and muscle quality were assessed using computed tomography, and strength was measured with an isokinetic dynamometer. NMES training intensity was calculated as a percentage by dividing NMES-elicited quadriceps muscle torque by the maximum voluntary isometric contraction. Improvements in muscle function were calculated using paired-sample t tests. The dose-response relationship was determined using curve estimation regression statistics. The minimum NMES training intensity was defined as that sufficient to significantly improve all muscle function measures.

RESULTS

Twenty-four people (48 legs) participated (75% women; mean [SD] age = 58 [8] years; mean body mass index = 32 [7] kg/m2). Quadriceps cross-sectional area, muscle quality, and strength improved after the intervention. Associations between NMES training intensity and muscle quality (r2 = 0.20) and strength (r2 = 0.23) were statistically significant, but that between NMES training intensity and muscle cross-sectional area was not (r2 = 0.02). The minimum NMES training intensity necessary to improve all measures of muscle function ranged from 11% to 20% of the maximum voluntary isometric contraction.

LIMITATIONS

The relatively small sample size was a limitation.

CONCLUSIONS

The minimum NMES training intensity for significant gains in muscle function was ∼15%. Higher NMES intensities may promote better muscle quality and strength in individuals with RA.

Extra-articular Manifestations and Comorbidity in Rheumatoid Arthritis: Potential Impact of Pre-Rheumatoid Arthritis Prevention

Rheumatoid arthritis (RA) is associated with a wide variety of extra-articular manifestations and comorbidities, several of which can be organ- or even life-threatening. These extra-articular manifestations and comorbidities can also contribute to the physical disability and psychological morbidity of RA that lead to reduced quality of life, higher direct and indirect costs, and societal burden of the disease. Although the expansion of RA treatment options and adoption of treat-to-target approaches has reduced the incidence and severity of several nonarticular manifestations of RA, such as rheumatoid vasculitis and cardiovascular disease events, this does not seem to be shared by all RA comorbidities. Moreover, a number of highly prevalent and impactful RA-driven comorbidities, such as accelerated atherosclerosis, interstitial lung disease, and sarcopenia, can present clinically in the years before the manifestation of joint pain or observable synovitis. A larger proportion of patients with RA have atherosclerosis, myocardial dysfunction, interstitial lung disease, and sarcopenia that is subclinical in the preclinical and earliest clinical phases of RA, emphasizing the importance of targeting the pre-RA phase for the prevention of comorbidities that are often poorly responsive to treatment once they develop. Herein, we review the potential impact of pre-RA prevention on the incidence and burden of extra-articular manifestations and nonarticular comorbidities.

pQCT- and Ultrasound-based Muscle and Fat Estimate Errors after Resistance Exercise

PURPOSE

Resistance exercise increases blood flow, induces osmotic and hydrostatic fluid shifts during and immediately after exercise, and may trigger inflammatory responses for several days in the working muscle. The resultant muscle swelling can subsequently affect muscle size and quality assessments. However, the effects of muscle swelling on x-ray attenuation of adipose estimate errors are unknown.

METHODS

Peripheral quantitative computed tomography (pQCT) and ultrasonography were used to assess muscle and adipose tissue properties of both upper arms before, 24, 48, and 72 h after unilateral resistance exercise. Recreationally active participants (n = 17) completed the exercise while their contralateral limb served as a control.

RESULTS

Resistance exercise resulted in a significant increase in pQCT-derived muscle cross-sectional area (includes intermuscular adipose tissue [IMAT] area), muscle area (excludes IMAT area) and IMAT area, and ultrasound-derived muscle thickness at 24, 48, and 72 h. A significant decrease in pQCT-derived muscle density was also detected as well as an increase in ultrasound-derived echo intensity at 48 and 72 h. The changes in muscle area, IMAT area, and muscle density were significantly correlated with changes in echo intensity, whereas the changes in muscle cross-sectional area and IMAT area were significantly correlated with changes in muscle thickness.

CONCLUSION

Unaccustomed resistance exercise can cause errors in pQCT- and ultrasound-based muscle and adipose estimates for at least 72 h. These errors are the result of muscle swelling likely caused by muscle blood flow and inflammation-dependent fluid shifts in muscle. These findings may have implications for measurements in other inflammatory conditions.

Prevalence of frailty and its associated factors in patients with rheumatoid arthritis: a cross-sectional analysis

OBJECTIVES

The aims of the present research were to assess the prevalence of frailty and its potential associated factors in a cohort of adult patients with rheumatoid arthritis (RA).

METHODS

Consecutive RA patients and healthy controls were assessed according to the Survey of Health, Ageing and Retirement in Europe Frailty Instrument (SHARE-FI), and classified as frail, pre-frail, or non-frail. Chi-square, analysis of variance (ANOVA), and multinomial logistic regression analyses were used to test the prognostic value of frailty for the outcomes of interest.

RESULTS

Two hundred and ten consecutive RA patients (65.7% female, mean age 60.4 years) and 100 healthy controls (63% female, mean age 59.1 years) were included. According to SHARE-FI criteria, 35 RA patients (16.6%) were categorized as frail, 68 (32.4%) as pre-frail, and 107 (51%) as non-frail, while 8 control subjects were categorized as frail, (8%), 17 as pre-frail (17%), and 75 as non-frail (75%) (chi-squared 12.8; P = 0.0016). The results from logistic regression analysis revealed that age (odds ratio [OR] = 1.12, 95% confidence interval [CI] = 1.07-1.17; P < 0.0001), comorbidities (OR = 1.51, 95% CI = 1.01-2.27; P = 0.0446), and high disease activity (OR = 1.10, 95% CI = 1.04-1.16; P = 0.0006) were independently associated with frailty in RA.

CONCLUSIONS

Frailty or pre-frailty are common in RA. The SHARE-FI may be a useful tool for the screening of frailty in RA and may summarize the results of a comprehensive RA assessment providing a marker of deficits accumulation.

Intramuscular Fat Accumulation and Associations With Body Composition, Strength, and Physical Functioning in Patients With Rheumatoid Arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is associated with adverse body composition profiles and low muscle density due to the accumulation of intramuscular fat. Linear regression was used to assess differences between RA patients and controls and to determine associations between muscle density, strength, and physical functioning.

METHODS

Patients with RA, ages 18-70 years, and healthy control subjects underwent whole-body dual x-ray absorptiometry and peripheral quantitative computed tomography, in order to quantify the appendicular lean mass index (ALMI) and the fat mass index (FMI), visceral fat area, and muscle density. Dynamometry was used to measure hand grip strength and muscle strength at the knee and lower leg. Disability and physical functioning were measured using the Health Assessment Questionnaire (HAQ) and the Short Physical Performance Battery (SPPB). Linear regression analyses were performed to assess differences related to RA and associations between muscle density, strength, and function.

RESULTS

The study group included 103 patients with RA (51 men) and 428 healthy control subjects. Among patients with RA, low muscle density was associated with higher disease activity, C-reactive protein and interleukin-6 levels, greater total and visceral fat area, lower ALMI Z scores, physical inactivity, and long-term use of glucocorticoids (>1 year). Patients with low ALMI Z scores had lower muscle density Z scores compared with reference participants with similarly low ALMI scores. Low muscle density was independently associated with lower muscle strength, higher HAQ scores, and lower SPPB scores, after adjustment for ALMI and FMI Z scores.

CONCLUSION

The low muscle density observed in patients with RA was associated with low muscle mass, excess adiposity, poor strength, and greater disability. Interventions to address poor muscle quality could potentially affect important functional outcomes.

Sarcopenia

Sarcopenia is defined as a combination of low muscle mass with low muscle function. The term was first used to designate the loss of muscle mass and performance associated with aging. Now, recognized causes of sarcopenia also include chronic disease, a physically inactive lifestyle, loss of mobility, and malnutrition. Sarcopenia should be differentiated from cachexia, which is characterized not only by low muscle mass but also by weight loss and anorexia. Sarcopenia results from complex and interdependent pathophysiological mechanisms that include aging, physical inactivity, neuromuscular compromise, resistance to postprandial anabolism, insulin resistance, lipotoxicity, endocrine factors, oxidative stress, mitochondrial dysfunction, and inflammation. The prevalence of sarcopenia ranges from 3% to 24% depending on the diagnostic criteria used and increases with age. Among patients with rheumatoid arthritis 20% to 30% have sarcopenia, which correlates with disease severity. Sarcopenia exacts a heavy toll of functional impairment, metabolic disorders, morbidity, mortality, and healthcare costs. Thus, the consequences of sarcopenia include disability, quality of life impairments, falls, osteoporosis, dyslipidemia, an increased cardiovascular risk, metabolic syndrome, and immunosuppression. The adverse effects of sarcopenia are particularly great in patients with a high fat mass, a condition known as sarcopenic obesity. The diagnosis of sarcopenia rests on muscle mass measurements and on functional tests that evaluate either muscle strength or physical performance (walking, balance). No specific biomarkers have been identified to date. The management of sarcopenia requires a multimodal approach combining a sufficient intake of high-quality protein and fatty acids, physical exercise, and antiinflammatory medications. Selective androgen receptor modulators and anti-myostatin antibodies are being evaluated as potential stimulators of muscle anabolism.

Work Ability and Employment in Rheumatoid Arthritis: A Cross-Sectional Study on the Role of Muscle Strength and Lower Extremity Function

Objective

The aim of the present study was to assess the association between muscle strength, lower extremity function, employment status, and work ability in RA patients.

Methods

One hundred seropositive RA outpatients of working age were included in this cross-sectional study. Employment status was assessed by interview and work ability by the Work Ability Index-Single Item Scale (WAS). Muscle strength was determined using dynamometer measurement of isometric hand grip and knee extensor strength. Lower extremity function was measured using the short physical performance battery (SPPB). Regression models estimate the association between unemployment, work ability and muscle strength, and lower extremity function, controlling for sociodemographic and disease-related factors.

Results

Forty-one percent of the RA patients were not gainfully employed, and their median work ability had a good WAS value (7.00 [4.00-7.00]). Patients with better knee extensor strength (OR=1.07, 95% CI [1.02-1.12) and better physical performance (OR=1.71, 95% CI [1.18-2.49]) had a significantly better chance of gainful employment. The odds for hand grip strength remained significant when adjusted for sociodemographic (OR=1.5, 95% CI [1.00-1.09]), but not for disease-specific variables. Better hand grip strength (β=0.25, p=0.039) and better knee extensor strength (β=0.45, p=0.001) as well as better lower extremity function (SPPB) (β=0.51, p<0.001) remained significantly associated with work ability following adjustment for sociodemographic and disease-specific variables.

Conclusions

The association of employment status and work ability with parameters of physical fitness suggests that improvement in muscle strength and lower extremity function may positively influence work ability and employment in individuals with RA.

Sedentary behaviour in rheumatoid arthritis: definition, measurement and implications for health

RA is a chronic autoimmune disease characterized by high grade-inflammation, and associated with elevated cardiovascular risk, rheumatoid-cachexia and functional impairment. Sedentary behaviour (SB) is linked to heightened inflammation, and is highly pervasive in RA, likely as a result of compromised physical function and persistent fatigue. This high sedentarity may exacerbate the inflammatory process in RA, and hold relevance for disease-related outcomes. The aim of this narrative review is to provide an overview of the definition, measurement and health relevance of SB in the context of RA. Contradictions are highlighted with regard to the manner in which SB is operationalized, and the significance of SB for disease outcomes in RA is outlined. The advantages and disadvantages of SB measurement approaches are also discussed. Against this background, we summarize studies that have reported SB and its health correlates in RA, and propose directions for future research.

Skeletal Muscle Fat and Its Association With Physical Function in Rheumatoid Arthritis

OBJECTIVE

To characterize skeletal muscle fat (SMF), intermuscular adipose tissue (IMAT), and subcutaneous adipose tissue (SAT) in individuals with rheumatoid arthritis (RA), and assess the associations between these fat depots and physical function and physical activity.

METHODS

In a cross-sectional analysis from an RA cohort, SMF, IMAT, and SAT were measured using computed tomography imaging of the midthigh cross-sectional region. Physical function was measured using the Health Assessment Questionnaire (HAQ) and a battery of performance-based tests that included quadriceps muscle strength, gait speed, repeated chair-stands, stair ascent, and single-leg stance. Physical activity was assessed using an activity monitor. Associations between SMF, IMAT, and SAT and physical function and activity were assessed by multiple linear regression models adjusted for potential confounders such as age, sex, body mass index (BMI), muscle area, and muscle strength.

RESULTS

Sixty subjects with RA (82% female, mean ± SD age 59 ± 10 years, mean ± SD BMI 31.79 ± 7.16 kg/m² ) were included. In the adjusted models, lower SMF was associated with greater gait speed, single-leg stance, quadriceps strength, and physical activity, and less disability (R² Δ range 0.06-0.25; P < 0.05), whereas IMAT was not associated with physical function or physical activity and SAT was negatively associated with disability (HAQ) (R² Δ = 0.13; P < 0.05) and weakly but positively associated with muscle strength (R² Δ = 0.023; P < 0.05).

CONCLUSION

Fat infiltration within the muscle seems to independently contribute to low physical function and physical activity, contrary to IMAT or SAT accumulation. Longitudinal studies are necessary to confirm the impact of SMF on disability and health promotion in persons with RA.

The 8-foot up and go test is the best way to assess physical function in the rheumatoid arthritis clinic

Objectives

RA is characterized by poor physical function, which compromises patients’ quality of life and outcome. Clinical assessment of function is usually performed using self-reported questionnaires, such as the Multi-Dimensional HAQ (MDHAQ) and the Short Form-36 (physical component) (SF36-PC). However, such subjective measures may not accurately reflect real functional status. This study aimed to determine: (i) which clinically practicable objective test best represents overall physical function; and (ii) the extent to which self-reported subjective functional measures reflect objectively assessed function.

Methods

Objective [isometric knee extensor strength, handgrip strength, sit-to-stands in 30 s, 8-foot up and go (8′UG), 50-foot walk (50′W) and estimated aerobic capacity (V̇O₂max)] and subjective (MDHAQ and SF36-PC) measures of function were correlated with one another to determine the best overall test of functional status in 82 well-controlled RA patients (DAS28 (s.d.) = 2.8 (1.0)).

Results

In rank order of size, averaged correlations (r) to the other outcome measures were as follows: 8′UG: 0.650; 50′W: 0.636; isometric knee extensor strength: 0.502; handgrip strength: 0.449; sit-to-stands in 30 s: 0.432; and estimated V̇O₂max: 0.358. The MDHAQ was weakly (0.361) and the SF36-PC moderately correlated (0.415) with objective measures.

Conclusion

Our results show that the most appropriate measure of objective physical function in RA patients is the 8′UG, followed by the 50′W. We found discordance between objectively and subjectively measured function. In clinical practice, an objective measure that is simple and quick to perform, such as the 8′UG, is advocated for assessing real functional status.

Fatigue in Rheumatoid Arthritis

PURPOSE OF REVIEW

The purpose of this study was to review the current information on fatigue in rheumatoid arthritis (RA).

RECENT FINDINGS

Severe fatigue is common among individuals with RA and has a significant impact on quality of life (QOL). RA-related factors (e.g., inflammation, pain) are associated with greater fatigue, but other factors, such as obesity, physical inactivity, sleep disturbance, and depression, explain the majority of variation in fatigue. Medications targeting RA have little effect on fatigue. Instead, the most effective interventions seem to address non-RA-specific factors such as physical inactivity or use cognitive behavioral approaches. No recommendations have been made for tools to measure fatigue in RA, leading to potential difficulty comparing studies. Although fatigue has great impact on patients' QOL, effective interventions that are feasible for broad dissemination remain elusive. Additional multi-faceted research is needed to identify modifiable sources of fatigue. Such research would be enhanced by harmonization of fatigue measurement across studies.

Muscle Deficits in Rheumatoid Arthritis Contribute to Inferior Cortical Bone Structure and Trabecular Bone Mineral Density

OBJECTIVE

Rheumatoid arthritis (RA) is associated with muscle loss, osteoporosis, and fracture. We examined associations between skeletal muscle mass, strength, and quality and trabecular and cortical bone deficits in patients with RA and healthy controls.

METHODS

Participants, ages 18-75 years, completed whole-body dual-energy x-ray absorptiometry and peripheral quantitative computed tomography (pQCT) of the tibia to quantify appendicular lean mass and fat mass indices (ALMI, FMI), muscle density at the lower leg, trabecular bone density, and cortical bone thickness. Age-, sex-, and race-specific Z scores were calculated based on distributions in controls. Associations between body composition and pQCT bone outcomes were assessed in patients with RA and controls. Linear regression analyses assessed differences in bone outcomes after considering differences in body mass index (BMI) and body composition.

RESULTS

The sample consisted of 112 patients with RA (55 men) and 412 controls (194 men). Compared to controls, patients with RA had greater BMI Z score (p < 0.001), lower ALMI Z score after adjustment for FMI (p = 0.02), lower muscle strength Z score (p = 0.01), and lower muscle density Z score (p < 0.001). Among RA, ALMI Z scores were positively associated with trabecular density [β: 0.29 (0.062-0.52); p = 0.01] and cortical thickness [β: 0.33 (0.13-0.53; p = 0.002]. Associations were similar in controls. Bone outcomes were inferior in patients with RA after adjusting for BMI, but similar to controls when adjusting for body composition. Radiographic damage and higher adiponectin levels were independently associated with inferior bone outcomes.

CONCLUSION

Patients with RA exhibit deficits in cortical bone structure and trabecular density at the tibia and a preserved functional muscle-bone unit. A loss of mechanical loading may contribute to bone deficits.

Causes and consequences of fatigue in rheumatoid arthritis

PURPOSE OF REVIEW

To review current information on the causes, treatments, and consequences of fatigue in rheumatoid arthritis.

RECENT FINDINGS

Disease activity (inflammation, pain, joint symptoms) is associated with greater fatigue. However, disease activity per se accounts for only a small portion of fatigue, and rheumatoid arthritis medications that reduce disease activity have small effects on fatigue. Instead, factors outside the direct effects of rheumatoid arthritis, such as obesity, physical inactivity, sleep disturbance, and depression, explain the majority of variation in fatigue. Some of these factors may be indirect effects of disease (e.g. pain can lead to sleep disturbance). Rheumatoid arthritis has significant effects on the quality of life of individuals with rheumatoid arthritis. The most effective approaches to reducing rheumatoid arthritis fatigue appear to be behavioral, such as increasing physical activity, or cognitive, such as cognitive behavioral interventions.

SUMMARY

Fatigue in rheumatoid arthritis appears to be largely because of factors outside the direct effects of the disease, such as behavioral and psychological factors. In spite of the tremendous impact of fatigue on patient health and quality of life, effective treatments remain elusive, but existing data show that behavioral and cognitive approaches may be most effective.

A reproducible semi-automatic method to quantify the muscle-lipid distribution in clinical 3D CT images of the thigh

Many studies use threshold-based techniques to assess in vivo the muscle, bone and adipose tissue distribution of the legs using computed tomography (CT) imaging. More advanced techniques divide the legs into subcutaneous adipose tissue (SAT), anatomical muscle (muscle tissue and adipocytes within the muscle border) and intra- and perimuscular adipose tissue. In addition, a so-called muscle density directly derived from the CT-values is often measured. We introduce a new integrated approach to quantify the muscle-lipid system (MLS) using quantitative CT in patients with sarcopenia or osteoporosis. The analysis targets the thigh as many CT studies of the hip do not include entire legs The framework consists of an anatomic coordinate system, allowing delineation of reproducible volumes of interest, a robust semi-automatic 3D segmentation of the fascia and a comprehensive method to quantify of the muscle and lipid distribution within the fascia. CT density-dependent features are calibrated using subject-specific internal CT values of the SAT and external CT values of an in scan calibration phantom. Robustness of the framework with respect to operator interaction, image noise and calibration was evaluated. Specifically, the impact of inter- and intra-operator reanalysis precision and addition of Gaussian noise to simulate lower radiation exposure on muscle and AT volumes, muscle density and 3D texture features quantifying MLS within the fascia, were analyzed. Existing data of 25 subjects (age: 75.6 ± 8.7) with porous and low-contrast muscle structures were included in the analysis. Intra- and inter-operator reanalysis precision errors were below 1% and mostly comparable to 1% of cohort variation of the corresponding features. Doubling the noise changed most 3D texture features by up to 15% of the cohort variation but did not affect density and volume measurements. The application of the novel technique is easy with acceptable processing time. It can thus be employed for a comprehensive quantification of the muscle-lipid system enabling radiomics approaches to musculoskeletal disorders.

Workability and Muscle Strength in Patients With Seropositive Rheumatoid Arthritis: Survey Study Protocol

Background

Rheumatoid arthritis (RA) and other rheumatic conditions not only fundamentally affect patients’ quality of life and physiological needs but are also negatively associated with work ability. The costs of poor work ability, which, in sum, are more than treatment costs, pose an economic burden to society and patients. Work ability in RA appears to be multifactorial; symptoms such as pain, swelling, and stiffness play a major role, as these directly affect functional disability. Also, RA patients typically suffer from reduced muscle strength. Lower extremity function and grip strengths especially impair their quality of life. However, the role of muscle strength and disease activity as determinants of work ability have not yet been studied.

Objective

The primary objective of this study is to compare work ability in working-age participants with seropositive RA and with high and low disease activity; the secondary objective is to evaluate the association of muscle strength, functional ability, and frailty with work ability.

Methods

This monocentric cross-sectional study will be conducted at a rheumatologic outpatient clinic and day hospital with approximately 100 seropositive RA patients aged <65 years. A clinical disease activity index as a measure for rheumatoid disease activity will be assessed during the patients’ routine visits at the clinic. Work ability, frailty, and functional disability will be evaluated with (self-reported) questionnaires as well as with physical tests (Work Ability Index/Score; Health Assessment Questionnaire Disability Index; Survey of Health, Ageing, and Retirement in Europe Frailty Instrument; Short Physical Performance Battery). Muscle strength will be determined with dynamometer measurements of isometric hand grip strength and quadriceps femoris muscle contraction strength. Sleep quality (Medical Outcomes Study Sleep Scale) and sexual functioning as physiological needs will additionally be determined with self-reported questionnaires.

Results

For this study funding has already been awarded and enrollment has been completed. Data are currently being evaluated.

Conclusions

This study will evaluate the association of work ability with modifiable parameters such as muscle strength and functional ability. It will provide further insights into work ability in RA and its associated risk factors. Any evidence of association will motivate further research, and the findings might encourage interventions focused specifically on improving muscle strength and lower extremity function to positively affect work ability.

Trial Registration

ClinicalTrials.gov (NCT02581852); https://clinicaltrials.gov/ct2/show/NCT02581852 (Archived by WebCite at http://www.webcitation.org/6oNcelHtQ)

Frailty and reduced physical function go hand in hand in adults with rheumatoid arthritis: a US observational cohort study

Reduced physical function and health-related quality of life are common in rheumatoid arthritis (RA), and further studies are needed that examine novel determinates of reduced physical function in RA. This study examines whether frailty, a state of increased vulnerability to stressors, is associated with differences in self-reported physical function among adults with RA. Adults from a longitudinal RA cohort (n = 124) participated in the study. Using an established definition of frailty, individuals with three or more of the following physical deficits were classified as frail: (1) body mass index ≤18.5, (2) low grip strength (adjusted for sex and body mass index (BMI), measured by handheld dynamometer), (3) severe fatigue (measured by the Multidimensional Assessment of Fatigue), (4) slow 4-m walking speed (adjusted for sex and height), and (5) low physical activity (measured by the International Physical Activity Questionnaire). Individuals with one or two deficits were classified as "pre-frail" and those with no deficits as "robust." Self-reported physical function was assessed by the Health Assessment Questionnaire (HAQ) and the Valued Life Activities Difficulty scale. Regression analyses modeled associations of frailty category with HAQ and Valued Life Activities (VLA) Difficulty scores with and without controlling for age, sex, disease duration, C-reactive protein, use of oral steroids, and pain. Among adults with RA, being frail compared to being robust was associated with a 0.44 worse VLA score (p < 0.01) when the effects of covariates are held constant. Being frail, compared to being robust, is associated with clinically meaningful differences in self-reported physical function among adults with RA.

Serum biomarkers of inflammation and muscle strength among women with systemic lupus erythematosus

OBJECTIVES

Muscle strength is an important determinant of physical function in women with systemic lupus erythematosus (SLE). Serum biomarkers of inflammation, including interleukin-6 (IL-6) and C-Reactive Protein (CRP), are associated with differences in muscle strength among individuals without rheumatologic disease. We examined whether serum levels of IL-6 and CRP are associated with upper and lower extremity muscle strength among adult women with SLE.

METHODS

One hundred thirty-six women with SLE participated in this cross-sectional study. High-sensitivity CRP was analyzed by nephelometry. IL-6 serum levels were analyzed by high sensitivity enzyme-linked immunosorbent assay. Upper and lower extremity muscle strength were assessed by grip strength and peak torque of knee extension and flexion, respectively. Regression analyses modeled associations of CRP and IL-6 with upper and lower extremity muscle strength controlling for age, SLE duration, physical activity, prednisone use, BMI, plaquenil use, and pain.

RESULTS

Higher serum levels of IL-6 and CRP were associated with significantly weaker upper and lower extremity muscle strength even when controlling for covariates.

CONCLUSIONS

Increased serum IL-6 and CRP are associated with clinically significant differences in upper and lower extremity muscle strength and may be useful in identifying those at risk for weakness and decreased physical function.

The effects of bolus supplementation of branched-chain amino acids on skeletal muscle mass, strength, and function in patients with rheumatic disorders during glucocorticoid treatment

OBJECTIVES

To test the effects of bolus supplementation of branched-chain amino acids (BCAA) on skeletal muscle mass, strength, and function in patients with rheumatic disorders taking glucocorticoid (GC).

METHODS

Patients with rheumatic disorders treated with prednisolone (≥10 mg/day) were randomized to ingest additional daily 12 g of BCAA (n = 9) or not (n = 9) for 12 weeks. At baseline, and 4, 8, and 12 weeks, they underwent bioelectrical impedance analysis, muscle strength and functional tests, and computed tomography analysis for cross-sectional area of mid-thigh muscle.

RESULTS

Disease activities of the patients were well controlled and daily GC dose was similarly reduced in both groups. Limb muscle mass was recovered in both groups. Whole-body muscle mass and muscle strength and functional mobility were increased only in BCAA (+) group. The effects of BCAA supplementation on recovering skeletal muscle mass were prominent in particular muscles including biceps femoris muscle.

CONCLUSIONS

This trial is the first-in-man clinical trial to demonstrate that BCAA supplementation might be safe and, at least in part, improve skeletal muscle mass, strength, and function in patients with rheumatic disorders treated with GC.

The Obesity Epidemic and Consequences for Rheumatoid Arthritis Care

With the prevalence of obesity increasing dramatically worldwide over the past several decades, an increasing body of literature has examined the impact of obesity in the context of rheumatoid arthritis (RA). Epidemiologic studies suggest that obesity may be associated with a modestly increased risk for the development of RA, although these studies have shown conflicting results. Among patients with established RA, obesity has been observed to be associated with greater subjective measures of disease activity and poor treatment response, but also with a decreased risk of joint damage and lower mortality. A comprehensive evaluation of the influence of obesity on the measurement of disease, response to therapies, and long-term prognosis is critical in order to understand these observations. This review therefore focuses on recent observations, potential explanations for these findings, and implications for clinicians and investigators caring for and studying patients with RA.

Muscle Strength and Changes in Physical Function in Women With Systemic Lupus Erythematosus

OBJECTIVE

Cross-sectional studies have observed that muscle weakness is associated with worse physical function among women with systemic lupus erythematosus (SLE). The present study examines whether reduced upper and lower extremity muscle strength predict declines in function over time among adult women with SLE.

METHODS

One hundred forty-six women from a longitudinal SLE cohort participated in the study. All measures were collected during in-person research visits approximately 2 years apart. Upper extremity muscle strength was assessed by grip strength. Lower extremity muscle strength was assessed by peak knee torque of extension and flexion. Physical function was assessed using the Short Physical Performance Battery (SPPB). Regression analyses modeled associations of baseline upper and lower extremity muscle strength with followup SPPB scores controlling for baseline SPPB, age, SLE duration, SLE disease activity (Systemic Lupus Activity Questionnaire), physical activity level, prednisone use, body composition, and depression. Secondary analyses tested whether associations of baseline muscle strength with followup in SPPB scores differed between intervals of varying baseline muscle strength.

RESULTS

Lower extremity muscle strength strongly predicted changes over 2 years in physical function even when controlling for covariates. The association of reduced lower extremity muscle strength with reduced physical function in the future was greatest among the weakest women.

CONCLUSION

Reduced lower extremity muscle strength predicted clinically significant declines in physical function, especially among the weakest women. Future studies should test whether therapies that promote preservation of lower extremity muscle strength may prevent declines in function among women with SLE.