Changes in physical function over time in rheumatoid arthritis patients: A cohort study.

INTRODUCTION: Self-reported disability is potentially influenced by many factors in patients with rheumatoid arthritis (RA). In this sense, we evaluated the association between self-reported disability and (1) clinical features, (2) muscle strength and (3) physical performance over time among patients with RA from two distinct patient cohorts. MATERIALS AND METHODS: Two independent prospective RA cohorts were analyzed. The Health Assessment Questionnaire (HAQ), Disease Activity Score in 28 Joints (DAS28), handgrip test, chair stand test, timed-up-and-go (TUG) test and Short Physical Performance Battery (SPPB) were performed at baseline and in follow-up. T test for independent samples, Mann-Whitney U test, Spearman correlation coefficients and linear regression with generalized estimating equations were performed to assess associations between individual constructs at baseline and over time. RESULTS: A total of 205 total RA patients were included [North American Cohort (n = 115); Brazilian Cohort (n = 90)]. At enrollment, Brazilian men had better HAQ than North American men (p<0.001). Brazilian patients overall had lower muscle strength than North American patients (p<0.05). HAQ was associated with DAS28, handgrip test, chair stand test, TUG and SPPB (p<0.001) in both cohorts. Worsening of the DAS28 and chair stand test were each associated with worsening in HAQ in longitudinal analysis over time. Worsening of handgrip was also associated in with worsening HAQ in both cohorts (p<0.05). A worse TUG test was associated with worsening in HAQ in Brazilian cohort (p<0.05) and a worse SPPB was associated with worsening in HAQ in North American cohort (p<0.05). CONCLUSION: Greater disability measured by HAQ is closely associated with disease activity, pain, muscle strength, and physical performance among RA. Worsening in self-reported disability correlate with worsening clinical factors including objectively-observed physical function.

Sarcopenia in Immune-Mediated Rheumatic Diseases-Review.

INTRODUCTION: Sarcopenia is a condition characterized by decreased muscle strength and muscle mass, which can impact physical function. Sarcopenia develops as a consequence of age-related decline (primary sarcopenia) and has a major impact on physical, social, and emotional well-being. In addition, patients with rheumatic diseases may suffer from sarcopenia independently of aging (secondary sarcopenia). Exercise, pharmacological treatments, and nutritional supplementation are some of the strategies used for the management of sarcopenia in the general population. The aim of this review is to summarize the evidence around the prevalence and impact of sarcopenia in patients with rheumatic diseases. CONCLUSIONS: From our review, we can state that sarcopenia is a common and prevalent condition among the rheumatic diseases. Furthermore, the impacts of sarcopenia are not well-appreciated, and the implementation of treatment strategies has not been widespread. Strategies such as exercise and some pharmacological treatments are effective in improving physical and functional impairment related to these conditions. FUTURE RESEARCH DIRECTIONS IN THE FIELD: New pharmacological treatments are being actively studied and may contribute in the future to the management of sarcopenia.

Risk of Serious Infection With Low-dose Glucocorticoids in Patients With Rheumatoid Arthritis: An Instrumental Variable Analysis.

BACKGROUND: Low-dose glucocorticoids are commonly used in the treatment of rheumatoid arthritis (RA). Observational studies have found an increased risk of serious infection associated with low-dose glucocorticoids, but concerns about residual confounding remain. METHODS: We identified adults with RA on stable immunomodulatory therapy for >6 months receiving no glucocorticoids or ≤5 mg/day using Medicare data from 2006 to 2015. We used provider preference for glucocorticoids as an instrumental variable (IV) to assess associations between low-dose glucocorticoid use and the risk of infection requiring hospitalization using a cause-specific proportional hazards model. RESULTS: We identified 163,603 qualifying treatment episodes among 120,656 patients. Glucocorticoids ≤5 mg/day were used by 25,373/81,802 (31.0%) of patients seen by a rheumatologist with low provider preference for glucocorticoids and by 36,087/81,801 (44.1%) of patients seen by a rheumatologist with high provider preference for glucocorticoids (adjusted odds ratio 1.81, 95% confidence interval 1.77, 1.84 for association between provider preference and glucocorticoids). Chronic obstructive pulmonary disease, opioids, antibiotics, previous emergency department visits, hospitalizations, and infections requiring hospitalization infections were unbalanced with regard to exposure but not to the IV. The incidence of infection requiring hospitalization was 8.0/100 person-years among patients unexposed to glucocorticoids versus 11.7/100 person-years among those exposed. The association between glucocorticoids and infection requiring hospitalization from IV analysis (hazard ratio 1.26 [1.02-1.56]) was similar to results from a standard multivariable model (hazard ratio 1.24 [1.21-1.28]). CONCLUSIONS: Among patients with RA on stable immunomodulatory therapy, IV analysis based on provider preference demonstrated an increased risk of infection requiring hospitalization associated with low-dose glucocorticoids, similar to a traditional analysis.

Cachexia in patients with rheumatoid arthritis: a cohort study.

BACKGROUND: Rheumatoid arthritis (RA) is an inflammatory disease that leads to altered body composition. The loss of lean mass with a preservation or increase in fat mass has been termed rheumatoid cachexia (RC), to contrast with classic cachexia, which is characterized by severe weight loss. There are limited data on the prevalence and progression of cachexia in RA over time, as well as on associated factors. Our aim was to determine the prevalence of cachexia and to determine associations with potential factors. METHODS: This prospective cohort study recruited consecutively patients diagnosed with RA and followed for 1 year. The assessments were performed: clinical features, body composition, and physical function. RC and classic cachexia were assessed by several established diagnostic criteria. The pairwise Student's t test, Chi-square test, and GEE were performed (accepted at p ≤ 0.05). RESULTS: Of 90 patients recruited, 81 completed the study. Most patients were women (88.9%), and the mean age was 56.5 ± 7.3 years. At baseline, the median DAS28-CRP was 3.0 (IQR, 1.0-3.0), 13.3-30.0% of the included patients had RC, while none met criteria for classic cachexia. The prevalence of cachexia did not change after 12 months. Disease activity status and treatment with biologic disease-modifying antirheumatic drugs were significantly associated with changes on body composition and physical function (p < 0.05). CONCLUSIONS: In this cohort, RC was common, while classic cachexia was absent. Disease activity and use of biologic therapies were associated with changes on body composition and physical function, underscoring the importance of aiming for remission when treating RA.

Creatine kinase in the U.S. population: Impact of demographics, comorbidities, and body composition on the normal range.

BACKGROUND: Creatine kinase (CK) values are a critical part of the workup of suspected myopathies and are often assessed in patients that develop myalgia on statin therapy. CK elevations may influence the initiation and cessation of statin treatment, and incidentally discovered CK elevation may lead to further testing. A number of factors influence CK levels in healthy patients, but current reference ranges do not incorporate important influencers of CK such as race. Objectives of this study were to evaluate clinical factors associated with CK among healthy individuals and to develop practical reference ranges for important subgroups to improve test interpretation. METHODS: CK was evaluated in nonpregnant participants ≥20 years old from the cross-sectional National Health and Nutrition Examination Survey (NHANES) 2011-2014. Linear and logistic regression stratified by sex identified clinical factors associated with CK levels. Adjustment for anthropomorphic measures assessed whether age and race-ethnicity differences in CK were explained by differences in body composition. The 95th and 97.5th percentiles of CK in sex/race-ethnicity subgroups were calculated, excluding patients with recent strenuous exercise. RESULTS: A total of 10,096 nonpregnant adults were studied. Black race was strongly associated with CK. The odds ratio of having an abnormal CK for black women was 5.08 (95% CI 3.65-7.08) and for black men was 8.39 (95% CI 6.11-11.52). CK was substantially lower in older men. Differences in CK by age but not race-ethnicity were largely explained by body composition. Women with low body mass index were less likely to have an elevated CK, and overweight or obese men had an almost 2-fold greater odds of having an elevated CK. The 97.5th percentile of CK was 382 (95% CI 295-469) in white men, 1001 (95% CI 718-1284) in black men, 295 (95% CI 216-374) in white women, and 487 (95% CI 310-664) in black women. CONCLUSION: CK is substantially higher in men and in black patients. Differences in body size and composition are also important but do not explain racial differences in CK. The 95th and 97.5th percentiles in sex and race-ethnicity subgroups provide a practical guide for clinicians interpreting CK values.