类风湿性关节炎患者骨密度及骨代谢生化标志物的变化

Changes of bone mineral density and bone metabolic biochemical markers in patients with rheumatoid arthritis

目的通过测定骨密度和骨代谢指标了解类风湿关节炎(RA)患者骨质疏松的发生情况、骨代谢指标的变化及其影响因素。方法应用双能X线吸收法(DXA)测定110例(男28例,女82例)RA患者和120例(男30例,女90例)正常人腰椎L1-4和股骨近端骨密度,骨代谢指标血清I型胶原氨基末端肽(NTX-1)、骨碱性磷酸酶(B-ALP)及相关临床指标。结果RA组男性、绝经前及绝经后女性各组腰椎骨密度均较对照组减低(P<0.05),以绝经后女性下降显著(P<0.01);RA骨质疏松组患者(26例,23.6%)股骨颈骨密度值与病程、关节肿胀数、关节压痛数、ESR、CRP、X线分期负相关(P<0.05),与RF无明显相关性(P>0.05)。NTX-1水平在RA患者骨量正常组、骨量减少组、骨质疏松组依次升高,且组间两两比较差异有显著性(P<0.05);与骨质疏松组比较,骨量正常组和骨量减少组的ESR、CRP水平显著降低(P<0.05),B-ALP显著增加(P<0.05),而这两组间的B-ALP、ESR、CRP水平差异无显著性(P>0.05)。RA患者NTX-1与CRP水平呈正相关(P<0.05)。结论 RA继发骨质疏松十分常见,骨代谢指标NTX-1及B-ALP测定可作为早期活动性指标。

Objective To investigate the prevalence of osteoporosis, the changes of bone metabolic biochemical markers, and the related factors in the patients with rheumatoid arthritis （RA）. Methods Bone mineral density （BMD） of lumbar spine L1-4 and the proximal femur were measured using dual energy X-ray absorptiometry （DXA） in 110 RA patients （28 males and 82 females） and 120 normal people （30 males and 90 females）. The bone metabolic biochemical markers, serum procollagen type I amino terminal peptide （NTX-1） and bone alkaline phosphatase （B-ALP）, and related clinical indicators were also measured. Results BMD of the lumbar spine in men, premenopausal and postmenopausal women in RA group were lower than that in the control group （P 〈 0. 05 ）, and it decreased most significantly in postmenopausal women （P 〈 0. 01 ）. BMD of the hip in osteoporosis patients in RA group （26 cases, 23.6% ） was negatively correlated with disease duration, number of swollen joints, tender joint count, ESR, CRP, and X-ray stage （P 〈 0.05 ）, but was not significantly correlated with RF （ P 〉 0.05 ）. NTX-1 level gradually increased in RA patients in normal bone mass group, osteopenia group, and osteoporosis group, and there were significant differences between any two groups （P 〈 0.05）. Compared with those in osteoporosis group, the levels of ESR and CRP were significantly decreased in normal bone mass group and osteopenia group （ P 〈 0. 05 ）, but the level of B-ALP was significantly increased （ P 〈 0.05 ）. There were no significant differences between the normal bone mass group and osteopenia group in the levels of B-ALP, CRP, and ESR. The level of NTX - 1 was positively correlated with the level of CRP （P 〈 0.05 ）. Conclusion Osteoporosis in RA is common. Bone metabolic biochemical markers NTX - 1 and B-ALP may be measured as an activity index in the early stage.