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.

中文翻译：

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类风湿关节炎患者的恶病质：一项队列研究。

背景技术类风湿关节炎（RA）是一种炎症性疾病，其导致身体组成改变。保留或增加脂肪量的瘦体重的丧失已被称为类风湿恶病质（RC），与典型的恶病质形成鲜明对比，后者的特征是体重严重减轻。关于RA恶病质的流行和进展随时间推移以及相关因素的数据有限。我们的目的是确定恶病质的患病率，并确定与潜在因素的关联。方法这项前瞻性队列研究连续招募了确诊为RA的患者，并随访了1年。进行了评估：临床特征，身体组成和身体功能。RC和经典恶病质通过几种既定的诊断标准进行评估。成对学生t检验，卡方检验，进行了GEE和GEE（在p≤0.05时被接受）。结果在90名患者中，有81名完成了研究。大多数患者为女性（88.9％），平均年龄为56.5±7.3岁。基线时，DAS28-CRP的中位数为3.0（IQR，1.0-3.0），其中13.3-30.0％的患者患有RC，而没有患者符合经典恶病质的标准。12个月后恶病质的患病率没有改变。疾病活动状态和使用抗生物疾病的抗风湿药物治疗与身体成分和身体功能的变化显着相关（p <0.05）。结论在这个队列中，RC是常见的，而经典的恶病质则不存在。疾病活动和生物疗法的使用与身体成分和身体功能的变化有关，强调了在治疗RA时以缓解为目标的重要性。