Baker Joshua F, Von Feldt Joan Marie, Mostoufi-Moab Sogol, Kim Woojin, Taratuta Elena, Leonard Mary B
From the Division of Rheumatology, Philadelphia Veteran Affairs (VA) Medical Center; Division of Rheumatology, and Department of Biostatistics and Epidemiology, and Children's Hospital of Philadelphia, Department of Pediatrics, and Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Pediatrics and Medicine, Stanford University, Stanford, California, USA.J.F. Baker, MD, MSCE, Division of Rheumatology, Philadelphia VA Medical Center, and Division of Rheumatology, and Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania; J.M. Von Feldt, MD, MSEd, Division of Rheumatology, Philadelphia VA Medical Center, and Division of Rheumatology, Perelman School of Medicine, University of Pennsylvania; S. Mostoufi-Moab, MD, MSCE, Children's Hospital of Philadelphia, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania; W. Kim, MD, Department of Radiology, Perelman School of Medicine, University of Pennsylvania; E. Taratuta, MD, Department of Radiology, Perelman School of Medicine, University of Pennsylvania; M.B. Leonard, MD, MSCE, Department of Pediatrics and Medicine, Stanford University.
J Rheumatol. 2015 Nov;42(11):2038-45. doi: 10.3899/jrheum.150280. Epub 2015 Sep 1.
Rheumatoid arthritis (RA) is associated with low muscle mass and density. The objective of our study was to evaluate associations between 2 serum biomarkers [insulin-like growth factor 1 (IGF-1) and adiponectin] and skeletal muscle in RA.
Whole-body dual energy X-ray absorptiometry measures of the appendicular lean mass index (ALMI; kg/m(2)) and total fat mass index (kg/m(2)), as well as the peripheral quantitative computed tomography measures of the lower leg muscle and fat cross-sectional area (CSA; cm(2)) and muscle density (an index of fat infiltration) were obtained from 50 participants with RA, ages 18-70 years. Multivariable linear regression analyses evaluated associations between body composition and levels of adiponectin and IGF-1, adjusted for age, sex, and adiposity.
Greater age was associated with higher adiponectin (p = 0.06) and lower IGF-1 (p = 0.004). Eight subjects had IGF-1 levels below the reference range for their age and sex. These subjects had significantly lower ALMI and muscle CSA in multivariable models. Lower IGF-1 levels were associated with greater clinical disease activity and severity, as well as low ALMI, muscle CSA, and muscle density (defined as 1 SD below normative mean). After adjusting for age and sex, greater adiponectin levels were associated with lower BMI (p = 0.02) as well as lower ALMI, and lower muscle CSA, independent of adiposity (p < 0.05). Only greater Health Assessment Questionnaire scores were significantly associated with lower adiponectin levels.
Low IGF-1 and greater adiponectin levels are associated with lower muscle mass in RA. Lower IGF-1 levels were seen in subjects with greater disease activity and severity.
类风湿关节炎（RA）与低肌肉量和低肌肉密度相关。我们研究的目的是评估两种血清生物标志物[胰岛素样生长因子1（IGF-1）和脂联素]与RA患者骨骼肌之间的关联。
对50名年龄在18至70岁之间的RA患者进行全身双能X线吸收法测量上肢瘦体重指数（ALMI；kg/m²）和总脂肪量指数（kg/m²），以及下肢肌肉和脂肪横截面积（CSA；cm²）的外周定量计算机断层扫描测量和肌肉密度（脂肪浸润指数）。多变量线性回归分析评估了身体成分与脂联素和IGF-1水平之间的关联，并对年龄、性别和肥胖程度进行了校正。
年龄越大，脂联素水平越高（p = 0.06），IGF-1水平越低（p = 0.004）。8名受试者的IGF-1水平低于其年龄和性别的参考范围。在多变量模型中，这些受试者的ALMI和肌肉CSA显著较低。较低的IGF-1水平与更高的临床疾病活动度和严重程度以及低ALMI、肌肉CSA和肌肉密度（定义为低于正常平均值1个标准差）相关。在调整年龄和性别后，较高的脂联素水平与较低的BMI（p = 0.02）以及较低的ALMI和较低的肌肉CSA相关，与肥胖无关（p < 0.05）。只有较高的健康评估问卷评分与较低的脂联素水平显著相关。
低IGF-1和较高的脂联素水平与RA患者较低的肌肉量相关。疾病活动度和严重程度较高的受试者中可见较低的IGF-1水平。
