Department of Medicine, Philadelphia VA Medical Center.
Department of Medicine, University of Pennsylvania Perelman School of Medicine.
Rheumatology (Oxford). 2022 May 30;61(6):2285-2294. doi: 10.1093/rheumatology/keab710.
We determined the prevalence of sarcopenic obesity in patients with RA using multiple methods and assessed associations with physical functioning.
This study evaluated data from three RA cohorts. Whole-body dual-energy absorptiometry (DXA) measures of appendicular lean mass index (ALMI, kg/m2) and fat mass index (FMI) were converted to age, sex and race-specific Z-Scores and categorized using a recently validated method and compared it to a widely-used existing method. The prevalence of body composition abnormalities in RA was compared with two reference populations. In the RA cohorts, associations between body composition and change in the HAQ and the Short Physical Performance Battery (SPPB) in follow-up were assessed using linear and logistic regression, adjusting for age, sex, race and study.
The prevalence of low lean mass and sarcopenic obesity was higher in patients with RA (14.2; 12.6%, respectively) compared with the reference population cohorts (7-10%; 4-4.5%, respectively, all P <0.05). There was only moderate agreement among methods of sarcopenic obesity categorization (Kappa 0.45). The recently validated method categorized fewer subjects as obese, and many of these were categorized as low lean mass only. Low lean mass, obesity and sarcopenic obesity were each associated with higher HAQ and lower SPPB at baseline and numerically greater worsening.
RA patients had higher rates of low lean mass and sarcopenic obesity than the general population. The recently validated methods characterized body composition changes differently from traditional methods and were more strongly associated with physical function.
我们使用多种方法确定 RA 患者的肌肉减少性肥胖患病率，并评估其与身体功能的关联。
本研究评估了三个 RA 队列的数据。通过全身双能 X 线吸收法（DXA）测量四肢瘦体重指数（ALMI，kg/m2）和脂肪质量指数（FMI），并转换为年龄、性别和种族特异性 Z 分数，并使用最近验证的方法进行分类，并与广泛使用的现有方法进行比较。比较 RA 人群中身体成分异常的患病率与两个参考人群。在 RA 队列中，使用线性和逻辑回归，在校正年龄、性别、种族和研究后，评估身体成分与随访中 HAQ 和短体物理表现电池（SPPB）变化之间的关联。
与参考人群队列（分别为 7-10%和 4-4.5%，均 P<0.05）相比，RA 患者的低瘦体重和肌肉减少性肥胖患病率更高（分别为 14.2%和 12.6%）。肌肉减少性肥胖分类方法之间的一致性仅为中等（Kappa 0.45）。最近验证的方法将较少的受试者归类为肥胖，其中许多仅被归类为低瘦体重。低瘦体重、肥胖和肌肉减少性肥胖在基线时均与更高的 HAQ 和更低的 SPPB 以及数值上更大的恶化相关。
与一般人群相比，RA 患者的低瘦体重和肌肉减少性肥胖发生率更高。最近验证的方法与传统方法不同，能更好地描述身体成分变化，与身体功能的关联更强。
