Department of Rheumatology, Nizam's Institute of Medical Sciences, Hyderabad, India.
J Rheumatol. 2011 Mar;38(3):434-8. doi: 10.3899/jrheum.100535. Epub 2010 Nov 15.
Various factors affect joint damage in rheumatoid arthritis (RA). The influence of body mass index (BMI) is not adequately known. As BMI is potentially modifiable, we studied its influence on radiological joint damage in patients with RA.
Treatment-naive patients with early RA (< 24 mo) were included. Demographic data were collected along with swollen joint count (SJC), tender joint count (TJC), erythrocyte sedimentation rate (ESR), and IgM-rheumatoid factor (IgM-RF). Radiographs of hands and feet were obtained. BMI and Disease Activity Score for 28-joint count (DAS28-ESR) were calculated. Joint damage was assessed using the Simplified Erosions Narrowing Score (SENS).
A total of 101 patients were studied (81 women; mean age 41.91 ± 11.99 yrs). Mean disease duration was 10.77 ± 6.73 months; 55 patients (54.5%) were IgM-RF-positive. Mean BMI was 22.82 ± 4.66 kg/m(2) with 24 (23.8%) patients having low, 42 (41.6%) normal, and 35 (34.7%) high BMI. Mean SENS score was 16.81 ± 11.10; mean DAS28 was 6.23 ± 0.96. Significant correlation was noted between SENS and DAS28 (r = 0.28; p < 0.005). There was significant negative correlation between BMI and SENS (r = -0.509; p < 0.0005). In patients with low BMI, mean SENS (26.62 ± 13.45) was significantly higher than in patients with normal (15.88 ± 8.38; p < 0.001) and high BMI (11.20 ± 7.32; p < 0.001). Patients with normal BMI also had significantly higher SENS scores than those with high BMI (p < 0.05). One-way ANOVA did not reveal significant differences in DAS28 between groups. SENS was significantly higher in the IgM-RF-positive group (19.55 ± 11.36) than in the IgM-RF-negative group (13.54 ± 9.94; p < 0.01); DAS28 was not different between the 2 groups (6.22 ± 0.98 vs 6.26 ± 0.96, respectively). Within the 2 IgM-RF groups, a significant negative correlation was seen between BMI and SENS. Multiple regression analysis revealed RF, DAS28, and BMI were independently associated with SENS. BMI accounted for 23.04% of the variance in SENS independent of DAS28 and IgM-RF.
Low BMI is adversely associated with joint damage in patients with early RA.
多种因素会影响类风湿关节炎（RA）患者的关节损伤。目前尚不清楚体重指数（BMI）的影响。由于 BMI 可能是可改变的，我们研究了它对 RA 患者的放射学关节损伤的影响。
纳入了未经治疗的早期 RA（<24 个月）患者。收集了人口统计学数据，包括肿胀关节计数（SJC）、压痛关节计数（TJC）、红细胞沉降率（ESR）和 IgM-类风湿因子（IgM-RF）。拍摄手和脚的 X 光片。计算 BMI 和 28 关节疾病活动评分（DAS28-ESR）。使用简化侵蚀狭窄评分（SENS）评估关节损伤。
共纳入 101 例患者（81 名女性；平均年龄 41.91±11.99 岁）。平均病程为 10.77±6.73 个月；55 例（54.5%）患者 IgM-RF 阳性。平均 BMI 为 22.82±4.66kg/m²，24 例（23.8%）患者 BMI 较低，42 例（41.6%）患者 BMI 正常，35 例（34.7%）患者 BMI 较高。平均 SENS 评分为 16.81±11.10；平均 DAS28 为 6.23±0.96。SENS 与 DAS28 之间存在显著相关性（r=0.28；p<0.005）。BMI 与 SENS 之间存在显著负相关（r=-0.509；p<0.0005）。BMI 较低的患者的平均 SENS（26.62±13.45）明显高于 BMI 正常（15.88±8.38；p<0.001）和 BMI 较高（11.20±7.32；p<0.001）的患者。BMI 正常的患者的 SENS 评分也明显高于 BMI 较高的患者（p<0.05）。单因素方差分析显示，各组之间 DAS28 无显著差异。IgM-RF 阳性组的 SENS（19.55±11.36）明显高于 IgM-RF 阴性组（13.54±9.94；p<0.01）；两组之间 DAS28 无差异（分别为 6.22±0.98 和 6.26±0.96）。在 2 个 IgM-RF 组中，BMI 与 SENS 之间均存在显著负相关。多元回归分析显示，RF、DAS28 和 BMI 与 SENS 独立相关。BMI 占 SENS 变异的 23.04%，独立于 DAS28 和 IgM-RF。
低 BMI 与早期 RA 患者的关节损伤呈负相关。
