Department of Rheumatology & Immunology, The Affiliated Hospital of Jiangsu University, Zhenjiang, China.
Zhenjiang First People's Hospital, Zhenjiang, China.
Clin Rheumatol. 2023 Dec;42(12):3333-3340. doi: 10.1007/s10067-023-06725-2. Epub 2023 Aug 30.
Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease in adults that is associated with significant joint issues and systemic inflammation. One of the signs of bone damage in RA is osteoporosis (OP). Leptin is an inflammatory protein that has been reported to be related to RA. The potential relationships among leptin, disease activity, and OP in Chinese patients with RA are not well known.
In total, 245 patients with RA and 120 healthy controls were included in this study. Detailed data on the clinical characteristics and laboratory features were collected. Information about physical activity and functional status was recorded using specific questionnaires. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA). The MECALL castor-50-hf model X-ray scanner was used for the two-hand (including wrist) photographs.
Serum leptin levels differed significantly between the RA group and healthy control subjects (1.27/3.29 vs. 0.17/0.24, Z=13.29, P<0.001). The positive rate of leptin protein in RA patients was 86.35%, which was higher than that in controls (19.55%) (χ=28.51, P<0.001). Pearson's correlation test showed that morning stiffness, disease duration, joint swelling, joint tenderness, swollen joint count (SJC), tender joint count (TJC), health assessment questionnaire (HAQ) score, and Sharp-van der Heijde method (Sharp) score were positively correlated with the level of serum leptin (r=0.212, r=0.312, r=0.322, r=0.501, r=0.291, r=0.334, P<0.05). There was a clear increasing trend in the level of serum leptin according to the different disease activity scores and in the 28 joint activity (DAS28) groups (F=13.936, P<0.001). Elevated leptin was a risk factor for increased disease activity and OP according to logistic regression analysis. The median leptin level differed significantly between the normal bone mass group, osteopenia group, and OP group (P<0.001). An increased serum leptin level was a risk factor for RA-induced osteoporosis according to logistic regression analysis (P<0.001).
These results suggest that the level of serum leptin is associated with disease activity and secondary OP among Chinese patients with RA. Key Points • Serum leptin levels in RA patients are higher than those in normal control group. • Leptin was associated with disease activity. • Leptin was associated with the occurrence of systemic osteoporosis and affects bone erosion in RA patients.
类风湿关节炎（RA）是一种成人慢性自身免疫性疾病，与关节问题和全身炎症有关。RA 患者骨损伤的一个标志是骨质疏松症（OP）。瘦素是一种炎症蛋白，据报道与 RA 有关。中国 RA 患者瘦素、疾病活动度和 OP 之间的潜在关系尚不清楚。
本研究共纳入 245 例 RA 患者和 120 例健康对照者。收集详细的临床特征和实验室特征数据。使用特定问卷记录身体活动和功能状态信息。通过双能 X 线吸收法（DXA）测量骨密度（BMD）。使用 MECALL 蓖麻 50-hf 模型 X 射线扫描仪对双手（包括手腕）进行拍照。
RA 组与健康对照组血清瘦素水平差异有统计学意义（1.27/3.29 与 0.17/0.24，Z=13.29，P<0.001）。RA 患者瘦素蛋白的阳性率为 86.35%，高于对照组（19.55%）（χ=28.51，P<0.001）。Pearson 相关检验显示，晨僵、病程、关节肿胀、关节压痛、肿胀关节数（SJC）、压痛关节数（TJC）、健康评估问卷（HAQ）评分和 Sharp-van der Heijde 评分（Sharp）与血清瘦素水平呈正相关（r=0.212，r=0.312，r=0.322，r=0.501，r=0.291，r=0.334，P<0.05）。根据不同的疾病活动评分和 28 关节活动度（DAS28）组，血清瘦素水平呈明显升高趋势（F=13.936，P<0.001）。根据逻辑回归分析，升高的瘦素是疾病活动度和 OP 增加的危险因素。根据逻辑回归分析，正常骨量组、骨量减少组和 OP 组之间的血清瘦素水平差异有统计学意义（P<0.001）。血清瘦素水平升高是 RA 所致骨质疏松症的危险因素（P<0.001）。
这些结果表明，中国 RA 患者血清瘦素水平与疾病活动度和继发性 OP 有关。关键点• RA 患者血清瘦素水平高于正常对照组。• 瘦素与疾病活动度相关。• 瘦素与全身骨质疏松症的发生有关，并影响 RA 患者的骨侵蚀。
