Risk Factors of Muscle Wasting in Women with Rheumatoid Arthritis: Relevance of the Persistent Failure of Conventional Combination Therapy

Background: Muscle wasting, also known as myopenia, is frequent in rheumatoid arthritis (RA). To date, it is still unknown if the failure of pharmacologic therapies increases the risk of myopenia in RA. Objective: To identify if treatment failure with conventional synthetic DMARDs (csDMARDs) constitutes an independent risk factor of muscle wasting in women with RA. Methods: This was a cross-sectional study. We included 277 women with RA. Assessments in RA patients included: clinical, epidemiological, and therapeutic variables. The skeletal muscle index (SMI) was estimated by DXA, and myopenia was diagnosed if they had an SMI 2. Multivariable logistic regression models identified risk factors of myopenia. Results: Muscle wasting was observed in 28.2% of patients with RA. The risk factors of myopenia in RA were menopausal (OR: 4.45, 95% CI: 1.86 to 10.64) and failure of combined therapy with csDMARDs (OR: 2.42, 95% CI: 1.15 to 5.07). The increased body mass index was protective (OR:0.81, 95% CI: 0.75 to 0.87). Conclusions: Around one of four patients with RA presented muscle wasting. Muscle wasting is related to treatment failure of combined csDMARDs; other factors influencing the presence of muscle wasting is being postmenopausal, whereas, the body mass index was a protective factor

Serum Neuropeptide Y Levels Are Associated with TNF-α Levels and Disease Activity in Rheumatoid Arthritis

Background. Neuropeptide Y (NPY) is a sympathetic neurotransmitter with effects on the regulation of inflammatory cells. The role of NPY on autoimmune inflammatory diseases such as rheumatoid arthritis (RA) is not completely understood. Therefore, we evaluate if NPY levels are markers of disease activity in RA and if there is a correlation between NPY levels and tumor necrosis factor-alpha (TNF-α), leptin, and interleukin 6 (IL-6) levels. Methods. Cross-sectional design, including 108 women with RA. We assessed disease activity by DAS28-ESR (considering active disease a score of ≥2.6). Serum NPY levels and anti-CCP2 antibody, TNF-α, IL-6, and leptin levels were quantified (ELISA). Results. Sixty-eight RA had an active disease (RA-active), and 40 were in remission (RA-remission). RA-active patients had higher NPY levels vs. RA-remission (22.8±13.6 vs. 17.8±10.3; p=0.04). NPY levels correlated with increased TNF-α levels (r=0.32, p=0.001). Leptin or IL-6 did not correlate with NPY levels. In the logistic regression analysis, NPY increased the risk of disease activity (OR: 1.04, 95% CI 1.006-1.09, and p=0.03). Conclusion. Higher NPY levels are an independent marker of disease activity in RA. This study encourages the quantification of NPY levels as a surrogate marker for RA-active. Future studies evaluating the role of NPY levels interacting with other proinflammatory cytokines are required