Objective

To compare skeletal muscle fat (SMF), intermuscular adipose tissue (IMAT) and subcutaneous adipose tissue (SAT) between individuals with rheumatoid arthritis (RA), and healthy individuals of the same age, and healthy individuals at least 10 years older than those with RA.

Methods

Two cross-sectional studies. In the first study, RA subjects were matched by age, sex, and BMI with healthy adults. In the second, RA subjects were matched by sex and BMI to adults 10–20 years older. SMF, IMAT and SAT were measured with Computed Tomography images of the mid-thigh region. We used parametric or non-parametric related-sample tests to compare fat accumulation between RA subjects and healthy adults.

Results

In the first study SMF was significantly higher in the RA cohort compared to their age-matched healthy counterparts (mean difference = −3.5 HU (95% −6.2, −0.9), p = 0.011), but IMAT and SAT were similar between cohorts. In the second study, SMF, IMAT and SAT were not significantly different between the RA and matched older healthy cohorts. In both studies, there were no significant differences in mid-thigh muscle area between RA subjects and healthy adults.

Conclusion

SMF accumulation in RA was higher than in healthy individuals of similar age, sex, BMI. Accumulation of fat within and around the muscles in RA was not different compared to the matched healthy older individuals, indicating that muscle fat accumulation in RA might mimic a pattern not different from healthy aging.

中文翻译：

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与健康成人相比，类风湿性关节炎患者的骨骼肌脂肪。

客观的

比较类风湿性关节炎 (RA) 患者与同龄健康人，以及至少比类风湿性关节炎患者年长 10 岁的健康人的骨骼肌脂肪 (SMF)、肌间脂肪组织 (IMAT) 和皮下脂肪组织 (SAT) RA。

方法

两项横断面研究。在第一项研究中，RA 受试者在年龄、性别和 BMI 方面与健康成人相匹配。第二，将 RA 受试者按性别和 BMI 与 10-20 岁以上的成年人进行匹配。SMF、IMAT 和 SAT 是用大腿中部区域的计算机断层扫描图像测量的。我们使用参数或非参数相关样本检验来比较 RA 受试者和健康成人之间的脂肪堆积。

结果

在第一项研究中，与年龄匹配的健康人群相比，RA 队列中的 SMF 显着更高（平均差异 = -3.5 HU（95% -6.2，-0.9），p = 0.011），但 IMAT 和 SAT 在队列之间相似. 在第二项研究中，SMF、IMAT 和 SAT 在 RA 和匹配的老年健康队列之间没有显着差异。在这两项研究中，RA 受试者和健康成人的大腿中部肌肉面积没有显着差异。

结论

RA 中的 SMF 积累高于相似年龄、性别、BMI 的健康个体。与匹配的健康老年人相比，RA 肌肉内和肌肉周围的脂肪积累没有差异，这表明 RA 肌肉脂肪积累可能模仿与健康衰老无异的模式。