Summers G D, Deighton C M, Rennie M J, Booth A H
Department of Rheumatology, Derby Hospitals NHS Foundation Trust, Derbyshire Royal Infirmary, London Road, Derby DE1 2QY, UK.
Rheumatology (Oxford). 2008 Aug;47(8):1124-31. doi: 10.1093/rheumatology/ken146. Epub 2008 Apr 30.
Rheumatoid cachexia is under-recognized in clinical practice. The loss of lean body tissue, which characterizes cachexia, is often compensated for by gain in body fat-so called 'cachectic obesity'-so that 85% or more RA patients have a normal BMI. Severe cachexia with loss of weight leads to increased morbidity and premature mortality but loss of muscle bulk with a normal BMI also associates with poor clinical outcomes. Increasing BMI, even into the obese range, is associated with less joint damage and reduced mortality. Measurement of body composition using DXA and other techniques is feasible but the results must be interpreted with care. Newer techniques such as whole-body MRI will help define with more confidence the mass and distribution of fat and muscle and help elucidate the relationships between body composition and outcomes. Cachexia shows little response to diet alone but progressive resistance training and anti-TNF therapies show promise in tackling this potentially disabling extra-articular feature of RA.
类风湿性恶病质在临床实践中未得到充分认识。恶病质的特征是瘦体组织的丧失，这通常会被身体脂肪的增加所补偿——即所谓的“恶病质性肥胖”——因此85%或更多的类风湿关节炎患者体重指数（BMI）正常。严重恶病质导致体重减轻，会增加发病率和过早死亡率，但BMI正常时肌肉量的减少也与不良临床结局相关。BMI增加，即使进入肥胖范围，也与较少的关节损伤和较低的死亡率相关。使用双能X线吸收法（DXA）和其他技术测量身体成分是可行的，但结果必须谨慎解读。诸如全身磁共振成像（MRI）等新技术将有助于更准确地确定脂肪和肌肉的质量及分布，并有助于阐明身体成分与结局之间的关系。恶病质对单纯饮食几乎没有反应，但渐进性抗阻训练和抗肿瘤坏死因子（TNF）疗法在应对类风湿关节炎这种潜在致残的关节外特征方面显示出前景。
