背景:患有青少年特发性关节炎(JIA)的青少年倾向于比其典型发展中的同龄人从事较少的体力活动。身体活动对骨骼发育至关重要,减少身体活动可能会对骨骼健康产生不利影响。因此,我们研究了JIA青少年和无JIA青少年对照组的全身骨矿物质含量(BMC)和面骨矿物质密度(aBMD)的差异.我们还检查了中度到剧烈体力活动(MVPA)之间的关系,瘦质量,和骨骼结果。
方法:参与者包括21名JIA青少年(14名女性,7名男性)和21名性别和年龄匹配的对照,年龄为10-20岁。评估包括:身高;体重;三单腿跳距离(TSLH);通过加速度计测量的MVPA;和全身BMC,aBMD,和使用双X射线吸收法测量的瘦体重。计算BMC和aBMD的经高度调整的z分数,并用于所有分析。多重线性混合效应模型检查了BMC和aBMD的组差异,适应性,成熟,MVPA,TSLH,和瘦质量。参与者集群,根据性别和年龄(18个月内),被认为是随机效应。
结果:患有JIA的青少年的总体aBMDz评分较低[β(95%CI);-0.58(-1.10至-0.07),p=0.03]和BMCz分数[-0.47(-0.91至-0.03),p=0.04]与对照相比。JIA青少年的平均每日MVPA比对照组低22.0分钟/天;然而,MVPA与aBMD无关[-0.01(-0.01至0.01),p=0.32]或BMC[0.00(-0.01至0.00),p=0.39]。瘦质量与aBMD[0.05(0.01至0.09)g/cm2,p=0.03]和BMC[0.06(0.03至0.10)g呈正相关,p<0.001]。
结论:与没有JIA的性别和年龄匹配的对照组相比,患有JIA的青少年的总体aBMD和BMC较低。骨结局的组差异与JIA青少年的MVPA参与较低无关。尽管如此,仍然应该鼓励身体活动,因为它可以促进身体健康。
BACKGROUND: Adolescents with juvenile idiopathic arthritis (JIA) tend to engage in less physical activity than their typically developing peers. Physical activity is essential for bone development and reduced physical activity may detrimentally effect bone health. Thus, we examined differences in total body bone mineral content (BMC) and areal bone mineral density (aBMD) between adolescents with JIA and adolescent controls without JIA. We also examined associations between moderate-to-vigorous physical activity (MVPA), lean mass, and bone outcomes.
METHODS: Participants included 21 adolescents with JIA (14 females, 7 males) and 21 sex- and age-matched controls aged 10-20 years. Assessments included: height; weight; triple-single-leg-hop distance (TSLH); MVPA by accelerometry; and total body BMC, aBMD, and lean mass measured using dual X-ray absorptiometry. Height-adjusted z-scores were calculated for BMC and aBMD and used for all analyses. Multiple linear mixed effects models examined group differences in BMC and aBMD, adjusting for sex, maturity, MVPA, TSLH, and lean mass. Participants clusters, based on sex and age (within 18 months), were considered random effects.
RESULTS: Adolescents with JIA had lower total body aBMD z-scores [β (95% CI); -0.58 (-1.10 to -0.07), p = 0.03] and BMC z-scores [-0.47 (-0.91 to -0.03), p = 0.04] compared with controls. Mean daily MVPA was 22.0 min/day lower in adolescents with JIA than controls; however, MVPA was not associated with aBMD [-0.01 (-0.01 to 0.01), p = 0.32] or BMC [0.00 (-0.01 to 0.00), p = 0.39]. Lean mass was positively associated with aBMD [0.05 (0.01 to 0.09) g/cm2, p = 0.03] and BMC [0.06 (0.03 to 0.10) g, p < 0.001].
CONCLUSIONS: Adolescents with JIA had lower total body aBMD and BMC compared with sex- and age-matched controls without JIA. Group differences in bone outcomes were not associated with the lower MVPA participation of adolescents with JIA. Despite this, physical activity should still be encouraged as it promotes physical well-being.