Study Of Correlation Between Serum Adipokines And Sarcopenia And Osteoporosis In Patients With Rheumatoid Arthritis

Objective To systematically evaluate the changes and clinical values of serum adipocytokines visfatin and resistin in patients with rheumatoid arthritis（RA）,and their correlation between sarcopenia and osteoporosis（OP）in RA patients.MethodsOne hundred and eighty-two patients who were strictly met the 2010 ACR/EULAR RA classification criteria and one hundred sex,age-matched healthy subjects（control group）were enrolled in the study.We meticulously recorded their clinical and laboratory features.Serum levels of visfatin and resistin were determined using enzyme-linked immunosorbent assay（ELISA）.Skeletal muscle mass was calculated by biological electrical impedance.Bone mineral density（BMD）at the total hip and lumbar vertebra were detected by dual energy X-ray absorptiometry（DEXA）.Using non-parametric test,x2 test,correlation,and multiple logistic regression analysis test to analyze numerical data and categorical data comparisons.ResultsCompared with the control group,Serum level of visfatin in RA patients was considerably higher（Z=10.511,P <0.001）and serum level of resistin was also remarkably raised competing to the control group（Z=12.610,P <0.001）.Using the serum visfatin and resistin concentrations of P95 in the healthy control group as the grouping criteria to group RA patients,the positive rate of visfatin in RA patients was42.31%（77/182）,which was considerably larger than 5%（5/100）in the control group（x2=43.559,P<0.001）,while the positive rate of resistin was 70.33%（128/182）,which was also tremendously higher than 5%（5/100）in the control group（x2=110.536,P<0.001）.Comparing the high value in serum visfatin and resistin group with normal serum visfatin and resistin group,there was no significant difference in swollen joint count（SJC）,tender joint count（TJC）,morning stiffness,VAS,CRP,DAS28,SDAI,CDAI and other disease activity indicators in RA patients（P> 0.05）.There was no significant difference between any parts of BMD in two visfatin groups as well as two resistin groups.The level of serum visfatin and resistin also failed to show statistic distinction in RA patients with or without sarcopenia（P>0.05）.It came to no statistic difference in the mass of skeletal muscle and SMI in two visfatin groups（P>0.05）.However,in 2 resistin groups,SMI levels as well as the skeletal muscle in high level serum resistin group of RA patients were visibly higher than the normal group（P<0.05）.Other than that,the visceral fat area and Abdominal obesity in high level serum resistin group were apparently decreased than normal group as well.Divided RA patients into three groups according to the level of DAS28,SDAI and CDAI respectively,the study failed to find the statistically diversity of serum levels of visfatin and resistin in RA patients（P>0.05）.By using whether combining OP or OPF,RA patients were divided into two groups,the serum level of resistin in RA patients with OPF was statistically lower than that in RA patients without OPF（z=2.054,P=0.040）,and there was no statistically difference in serum visfatin and resistin level among other groups（P>0.05）.Apart from above,in RA patients,serum visfatin level was positively associated with right lower limb muscle mass（r=0.238,P=0.001）and skeletal muscle mass（r=0.210,P=0.005）,it also positively correlated with hip BMD（r=0.146,P=0.050）.Meanwhile,serum resistin level was positively correlated with left upper limb muscle mass（r=0.147,P=0.047）,right upper limb muscle mass（r=0.256,P<0.001）,trunk muscle mass（r=0.146,P=0.049）as well as skeletal muscle mass（r=0.210,P=0.004）.Resistin level was also positively associated with neck BMD（r=0.159,P=0.032）and hip BMD（r=0.183,P=0.014）.Howbeit,SJC,TJC,morning stiffness,HAQ,VAS,X-ray stage,Sharp score,DAS28 failed to show any correlation with visfatin or resistin（P>0.05）.With regard to age,gender and BMI as calibrations,female（OR=44.272,95%CI:8.534-229.657,P<0.001）,aging（OR=1.123,95%CI:1.074-1.174,P<0.001）and Sharp score（OR=1.005,95%CI: 1.000-1.011,P=0.044）were risk factors in RA patients with OP,while BMI（OR=0.820,95%CI: 0.725-0.928,P=0.002）was a protective factor for OP in RA patients.Aging（OR=1.040,95%CI: 1.008-1.072,P=0.014）,Sharp score（OR=1.008,95%CI: 1.002-1.014,P=0.013）,high titer anti-CCP（OR=1.001,95%CI: 1.000-1.002,P=0.033）were risk factors for sarcopenia in RA,on the other hand,BMI（OR=0.674,95%CI: 0.580-0.784,P<0.001）was a protective factor in RA patients accompany with sarcopenia.As for disease activity,we only find VAS（OR=1.680,95%CI: 1.330-2.122,P<0.001）was a risk factor for RA patients with high disease activity evaluated by DAS28.Compared with serum visfatin concentration at4.335 ug/L（sensitivity: 98.4%,specificity: 66.0%）,serum resistin concentration at7.101 ug/L（sensitivity: 97.8%,specificity: 89.0%）has better specificity and sensitivity for the diagnosis of RA.ConclusionSerum visfatin level in RA patients was notably higher comparing to the level in the control group,as well as serum resistin level in RA patients was significantly higher comparing to that in the control group.They intently correlate with OPF and sarcopenia in RA.