Objective To investigate the effect of sarcopenia and vitamin D deficiency on osteoporosis (OP) in patients with rheumatoid arthritis (RA).Methods Six hundred and forty-eight patients with RA were enrolled into the study,while 158 normal subjects were recruited as the control group.Bone mineral density (BMD) at total hip and lumbar vertebra 2-4 were measured by dual energy X-ray absorptiometry (DEXA),limbs skeletal muscle mass was determined in 267 patients with RA and 156 normal subjects by bioelectrical impedance method.Serum 25-hydroxy vitamin D [25(OH)D] levels were determined by electrochemiluminescence in 234 RA patients and 68 normal subjects.Clinical and laboratory features,daily dosage and duration of glucocorticoid (GC) were recorded.Numerical data and categorical data comparisons were analyzed using t test,x2 test,linear correlation analysis,single factor analysis of variance test and Logistic regression analysis test.Results ① Incidence of OP in RA (37.8％,245/648) was significantly higher than that in the controls (13.9％,22/158)(x2=32.712,P＜0.01).Incidence of sarcopenia was evidently higher in RA,compared with normal subjects [55.8％(149/267),9.0％(14/156),x2=91.176,P＜0.01].Percentage of sarcopenia was higher in RA with OP compared with RA without OP group [76.6％(49/64),39.3％(35/89),x2=20.848,P＜0.01].②Compared to control group,serum 25 (OH)D levels were significantly lower in RA group [(13.4±9.7) ng/ml,(22.4±6.3) ng/ml,t=9.063,P＜0.01].Rate of vitamin D deficiency iu RA was also higher than that in controls [80.8％(189/234),36.8％(25/68),x2=49.412,P＜0.01].③The differences of serum 25 (OH)D levels among different bone metabolic state groups at lumbar vertebra in RA (normal bone mass,osteopenia,OP) were statistically significant (F=6.263,P=0.003),whichrepresented a clearly decreasing trend along with the decreasing of serum 25 (OH)D levels (P=0.001).④Linear correlation analysis found that skeletal muscle mass indexes at limbs in RA were positively correlated with BMD and serum 25 (OH)D levels (P＜0.05).⑥Logistic Regression analysis revealed that sarcopenia (OR=4.373,P=0.002),age (OR=1.083,P=0.001) and duration of disease (OR=1.074,P=0.029) were the risk factors for occurrence of OP in patients with RA.Conclusion Sarcopenia generally exists in patients with RA,which is correlated with decreasing of serum 25 (OH)D levels,and also is the risk factor for the occurring of OP in RA.

Objective To analyze and compare the clinical and laboratory features between patients with ankylosing spondylitis (AS) and nonradiographic axial spondyloarthritis (nr-axSpA).Methods One hundred and forty-one patients with AS and 73 cases with nr-axSpA were recruited.Clinical and laboratory indexes of individuals were recorded in detail,Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS) crp were calculated.Spondyloarthritis research consortium of Canada (SPARCC) score standard was used to evaluate the degree of bone marrow edema in sacr-oiliac joint under magnetic resonance imaging scanning.T test,rank test and x2 test were used for statistical analysis.Results The average age of patients with AS was obviously higher than that of patients with nr-axSpA (t=4.962,P＜0.01).Patients with AS were more often male,and those with nr-axSpA were more often female (82.0％ of the AS patients were men and 49.3％ of the nr-axSpA patients were men (x2=24.079,P＜0.01).Disease duration of AS was significantly longer than that of the nr-axSpA (Z=6.396,P＜0.01).The incidence of human leukocyte antigen (HLA)-B27 positive in AS was 89.4％,which was similar to that in patients with nr-axSpA (84.9％) (x2=0.884,P＞0.05).21.6％ (21 cases) of patients with AS had peripheral swollen joints,which was higher than that in nr-axSpA (2.2％,x2=8.861,P=0.003).Forty cases in AS had tender joints (41.2％),only 6 patients in nr-axSpA had tender joints (13.3％,x2=11.458,P＜0.01).Serum erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) levels in patients with AS were clearly higher than those in nr-axSpA (P＜0.01) patients.In AS,the patient global assessment (PGA),BASDAI and ASDAScrp value was significantly higher than that in nr-axSpA (P＜0.01).There were no differences in SPARCC score or incidence of bone marrow edema in sacroiliac joint in magnetic resonance imaging scanning between AS and nr-axSpA (P＞0.05).Percentage of patients with occipit-to-wall distance higher than 0 cm in AS was higher than that in nr-axSpA,and the mean distance of fingers to ground in AS was also higher than that in nr-axSpA (x2=19.844,P＜0.01;Z=5.724,P＜0.01).Chest expansion degree and Schboer's test in AS was much lower than that in nr-axSpA,respectively (Z=3.083,P=0.002;Z=5.103,P＜0.01).BASFI in AS was higher than that in nr-axSpA (Z=5.840,P＜0.01).The ratio of joint function in AS was obviously worse than that in nr-axSpA (x2=1 1.369,P=0.01).Conclusion Compared to patients with nr-axSpA,AS patients are male predominant,and have severer inflammation in clinical and laboratory findings and are worse in functional status.

Objective To investigate the clinical value of serum 14-3-3η protein levels in patients with rheumatoid arthritis (RA) and secondary osteoporosis (OP). Methods 259 RA patients and 80 healthy controls were recruited. Serum 14-3-3η levels were determined by ELISA and bone mineral density (BMD) were detected by the DEXA. Results Firstly, the levels and the positive rate of serum 14-3-3η protein were significantly high-er in RA patients than healthy controls (P < 0.000 1). Secondly, ROC curve revealed that the sensitivity of 14-3-3η protein for diagnosis of early RA was 91.7% and its specificity was 99.6% when the cut-off point was 0.879 ng/mL (AUC = 0.917, P < 0.000 1). Finally, 14-3-3η protein concentrations revealed significant differ-ence among the groups of bone mass normal, osteopenia and osteoporosis in early RA (χ2=7.974, P = 0.019). Conclusion Serum 14-3-3η protein levels increase significantly in RA , especially in early RA , which is relat-ed to clinical symptoms and osteoporosis.

Objective To investigate the value of serum levels of peroxisome proliferater-activated receptor (PPAR)γin patients with rheumatoid arthritis (RA) and to explore the associations between serum PPARγwith disease activity of RA and RA-associated osteoporosis (OP).Methods One hundred and one cases of hospitalized patients with RA were enrolled.A total of 88 normal subjects during the same period were recruited as the control group.Levels of serum PPARγwere detected by enzyme linked immunosorbent assay (ELISA).Bone mineral density (BMD) was measured by dual energy X-ray absortiometry.All the clinical and laboratory indexes of RA patients were recorded in detail.T-test (or t'-test) was used for comparison of measurement data between the two groups,non-parametric test was applied for skewed distribution data.Comparison of incidence was analyzed with x2 test,correlation analysis was represented ascorrelation coefficient (r).Results Binary logistic regression analysis was used for multivariate regression analysis.Serum levels of PPARγ(3.38/4.00 ng/ml) in RA patients were higher than thosein normal subjects (2.63/1.76) ng/ml (Z=3.204,P=0.001).The positive rate of serum levels of PPARγin RA was 35.6％ (36/101),while the positive rate in the controls was (2.3％,2/88,x2=32.602,P＜0.01).The incidence of OP in RA was 34.7％(35/101;while the levels of serum PPARγ in RA without OP at femur area (femoral neck,total hip) and lumbar spine (L1,L1-4) were higher than that in RA with OP (P＜0.05).Serum levels of PPARγ between groups with different disease activity had no significant difference (P＞0.05).Serum levels of PPARγ in RA with negative RF or negative anti-CCP were higher than thosetin the RA group with positive RF or positive anti-CCP(P＜0.05).Serum levels of PPARγ in RA were negatively correlated with serum RF,anti-CCP,hemoglobin (P ＜0.05-0.001),and positively correlated with erythrocyte sedimentation rate,platelet,BMD at sites of femur neck andWard (P＜0.05-0.001).Results of binary logistic regression analysis showed that levels of serum PPARγwere protective factors in RA for OP at femurneck [OR=0.577,P=0.005,95％CI (0.394-0.846)],and total hip [OR=0.754,P=0.033,95％CI (0.581-0.978)].Condusion Serum levels of PPARγ in patients with RA are significantly increased,and negatively correlate with autoantibodies.Serum levels of PPARγare protective factors for OP in RA.