类风湿关节炎全身骨量丢失及其相关危险因素的分析

Systemic bone loss and its related risk factors in patients with rheumatoid arthritis

目的探讨类风湿关节炎(RA)全身骨量丢失及其与骨转换、抗环瓜氨酸蛋白抗体(ACPA)的相关性。方法纳入确诊的RA患者并设立健康对照,酶联免疫吸附法测定血清核因子κB受体活化因子配体(RANKL)和骨保护素(OPG),电化学发光法检测血清I型胶原羧基端交联肽(I-CTX)和I型胶原氨基端前肽(PINP),双能X线吸收法测定腰椎和髋部骨密度,Spearman's相关系数进行相关性分析。结果入组RA患者95例,男性35例,女性60例,平均年龄(53.63±13.88)岁。RA患者腰椎和髋部骨密度均显著低于健康对照(-1.2±1.4,-0.6±0.8,P=0.002;-0.1±1.4,0.8±0.8,P<0.001),血清I-CTX和PINP与髋部骨密度显著负相关(r=-0.225,P=0.032;r=-0.299,P=0.004),血清ACPA与RANKL、OPG、I-CTX、PINP、腰椎和髋部骨密度均无显著相关性(P>0.05)。结论RA患者腰椎和髋部骨密度显著低于健康人群,高骨转换可能引起RA髋部骨量丢失,而ACPA可能不是引起RA患者全身骨量丢失的主要原因。

Objective To investigate systemic bone loss and its relationship with bone turnover and anti-citrullinated protein autoantibodies(ACPA)in patients with rheumatoid arthritis(RA).Methods Patients with RA and healthy controls were recruited in this study.Enzyme linked immunosorbent assay(ELISA)was used to detect serum levels of receptor activator of nuclear factor-κB ligand(RANKL)and osteoprotegerin(OPG).Serum concentrations of C-terminal telopeptide of type I collagen(I-CTX)and total aminoterminal propeptide of typeⅠcollagen(PINP)were measured by electrochemiluminescence.Bone mineral density(BMD)at the lumbar spine and total hip was evaluated by using dual-energy X-ray absorptiometry.Associations of BMD with bone turnover and ACPA in RA patients were examined by Spearman's correlation coefficients.Results Of the 95 RA patients,35 were males and 60 were females,with the median age of(53.63±13.88)years old.Bone mineral density(BMD)was included in the study.BMD at the lumbar spine and total hip decreased significantly in RA patients compared with the controls(-1.2±1.4,-0.6±0.8,P=0.002;-0.1±1.4,0.8±0.8,P<0.001).Increased serum I-CTX and PINP were significantly correlated with decreased BMD at the total hip in RA patients(correlation coefficient=-0.225,P=0.032;correlation coefficient=-0.299,P=0.004).We did not find associations of ACPA,RANKL,OPG,I-CTX,or PINP with BMD at the lumbar spine and the total hip(P>0.05).Conclusion BMD at the lumbar spine and total hip decreased significantly in RA patients compared with the controls.Increased bone turnover may play a role in bone loss at the total hip in RA patients.However,APCA may not be related to systemic bone loss in RA patients.