青少年强直性脊柱炎早期腰椎骨密度变化多因素分析

目的研究青少年强直性脊柱炎(ankylosingspondylitis,AS)早期年龄、身高、体质量、体质量指数(BMI)与L1-4骨矿含量(L1-4BMC)、L1-4面积骨密度(L1-4BMD)、L1-4体积表观骨密度(L1-4BMAD)之间的相关性,旨在初步探讨青少年AS早期骨量、骨密度研究的相关因素和评价指标。方法选择男性青少年强直性脊柱炎早期病例31例,获得年龄、身高、体质量、BMI,应用双能X线骨密度仪(DEXA)检测L1-4BMC,L1-4BMD,并计算L1-4BMAD;采用相关和回归分析研究多因素相关性。结果相关和回归分析表明,身高(P=0.000)和BMI(P=0.009)因素进入L1-4BMC回归方程(R=0.759,Radj2=0.545,P=0.000<0.01),其中身高是L1-4BMC回归方程的关键因素(R=0.676,Radj2=0.439,P=0.000)。另外,年龄、身高、体质量和BMI4因素中只有体质量因素被纳入L1-4BMD回归方程(R=0.657,Radj2=0.412,P=0.000)和L1-4BMAD回归方程(R=0.551,Radj2=0.280,P=0.001)。身高和BMI与L1-4BMC显著正相关,体质量则与L1-4BMD和L1-4BMAD呈显著正相关。结论身高和体质量因素即成为青少年AS早期骨矿含量和骨密度的重要相关因素。

Multiple factor analysis of lumbar spine bone mass and densities in adolescents with early ankylosing spondylitis

Aim To investigate t h e possible roles of age,body height,mass and body mass index(BMI )in Lumbar 1-4 bone mineral content (L 1-4 BMC),L 1-4 areal bone mineral density(L 1-4 4BMD)and L 1-4 volumetric bone mineral apparent density(L 1-4 BMAD)of Chinese adoles-cents with early ankylosing spondylitis(AS).Meth ods Thirty-one male Chinese adolescent outpatients with early AS were included .Age(y),total body mass(kg),height (cm)and body mass index(BMI,kg /m 2 )of subjects were obtained.L 1-4 4BMC(g)and L 1-4 BMD(g /cm 2 )were e-valuated by using DEXA,and L 1-4 BMAD(L 1-4 4BMC /Area 3/2 ,g /cm 3 )was subsequently calculated.Corre lation and multiple regression analyses were performed.Results Multiple regression revealed that h eight (P=0.00 0)and BMI (P=0.009)were significantly positively rela ted to L 1-4 4BMC(R=0.759,Radj 2 =0.545,P=0.000<0.01),and height played the pivotal role s in signific ant correlation with L 1-4 4BMC(R=0.676Radj 2 =0.439,P=0.000).Body mass significantly positivel y correlate d with both L 1-4 4BMD(R=0.657,Radj 2 =0.412,P=0.000)and L 1-4 BMAD(R=0.551,Radj 2 =0.280,P=0.001).Therefore,height as well as BMI significantl y p ositively correlated with L 1-4 4BMC and mass was definitely associated with both L 1-4 BMD and L 1-4 BMAD in ado-lescents with early AS in this study.Conclusion Height and mas s could have significantly positive effects on axial bone mass and densities of adolescents with early AS.