RESUMO
Objective To study the variation characteristics of peripheral blood β-catenin and DKK1 levels in patients with rheumatoid arthritis (RA) and the correlation with bone and joint damage.Methods One hundred and eight patients with RA (observation group) and 110 healthy individuals (control group) were selected.The bone mineral density(B MD) in the femur (femur neck,Ward area,greater trochanter,total femur area) and lumbar spine (L2,3,4) were measured by dual-energy X-ray absorptiometry instrument.X-ray for two hands were evaluated according to the Sharp score.The peripheral blood β-catenin and DKK1 levels were detected by enzyme-linked immunosorbent assay (ELISA).Multiple analysis was completed by multiple linear regression and Logistic regression.Results The peripheral blood DKK1 level in observation group was significantly higher than that in control group [(8.2 ±5.0) mg/L vs.(6.1 ±4.2)mg/L],there was statistical difference (t =2.452,P =0.025),but there was no statistical difference in β-catenin level between the 2 groups (t =15.947,P =0.142).Compared to control group,patients with RA had lower BMD at femur and lumbar spine (P ＜ 0.01).The incidence of osteoporosis in observation group was significantly higher than that in control group [31.5％ (34/108) vs.15.5％ (17/110)],there was statistical difference (x2 =9.289,P =0.005).The correlation analysis results showed that the peripheral blood DKK1 was positive correlation with erythrocyte sedimentation rate (ESR),28-jonit disease activity score (DAS28),alkaline phosphatase (AKP) and two hands X-ray joint narrowing space score in patient with RA (P ＜ 0.01 or ＜ 0.05) ;the peripheral blood β-catenin level was positively correlated with ESR and AKP (P ＜ 0.01 or ＜ 0.05).The multiple linear regression results showed that the disease duration,health assessment questionnaires (HAQ),DKK1 influenced two hands X-ray joint narrowing space score; but the age,disease duration,HAQ influenced two hands X-ray bony erosion score.The multiple Logistic regression results showed that the two hands X-ray Sharp score was the risk factor of osteoporosis at femur in patients with RA; but the age was the risk factor of osteoporosis at lumbar in patients with RA.Conclusions Peripheral blood DKK1 level in patients with RA increases significantly,while there is no apparent alteration in β-catenin level.Peripheral blood DKK1 level is correlated with disease activity and joint space narrow score.