On Exposure to Anorexia Nervosa, the Temporal Variation in Axial and Appendicular Skeletal Development Predisposes to Site-Specific Deficits in Bone Size and Density: A Cross-Sectional Study
作者:Ego Seeman、Magnus K. Karlsson、Yunbo Duan
DOI:10.1359/jbmr.2000.15.11.2259
日期:——
Skeletal development is heterogeneous. Throughout growth, bone size is more maturationally advanced than the mineral being accrued within its periosteal envelope; before puberty, appendicular growth is more rapid than axial growth; during puberty, appendicular growth slows and axial growth accelerates. We studied women with differing age of onset of anorexia nervosa to determine whether this temporal heterogeneity in growth predisposed to the development of deficits in bone size and volumetric bone mineral density (vBMD), which varied by site and severity depending on the age at which anorexia nervosa occurred. Bone size and vBMD of the third lumbar vertebra and femoral neck were measured using dual‐energy X‐ray absorptiometry in 210 women aged 21 years (range, 12–40 years) with anorexia nervosa. Results were expressed as age‐specific SDs (mean ± SEM). Bone width depended on the age of onset of anorexia nervosa; when the onset of anorexia nervosa occurred (1) before 15 years of age, deficits in vertebral body and femoral neck width did not differ (−0.77 ± 0.27 SD and −0.55 ± 0.17 SD, respectively); (2) between 15 and 19 years of age, deficits in vertebral body width (−0.95 ± 0.16 SD) were three times the deficits in femoral neck width (−0.28 ± 0.14 SD; p < 0.05 comparing the deficits), (3) after 19 years of age, deficits in the vertebral body width (−0.49 ± 0.26 SD; p = 0.05) were half that in women with earlier onset of anorexia nervosa. No deficit in bone width was observed at the femoral neck. Deficits in vBMD at the vertebra and femoral neck were independent of the age of onset of anorexia nervosa but increased as the duration of anorexia nervosa increased, being about 0.5 SD lower at the vertebra than femoral neck. We infer that the maturational development of a region at the time of exposure to disease, and disease duration, determine the site, magnitude, and type of trait deficit in anorexia nervosa. Bone fragility due to reduced bone size and reduced vBMD in adulthood is partly established during growth.
骨骼发育具有异质性。在整个生长过程中,骨大小比在其骨膜包膜内累积的矿物质更为成熟;青春期前,四肢生长比轴向生长更快;青春期期间,四肢生长减慢,轴向生长加速。我们研究了患有不同发病年龄的神经性厌食症的女性,以确定这种生长的时态异质性是否使骨骼大小和体积骨矿物质密度(vBMD)的缺陷易发生,这些缺陷根据神经性厌食症发病年龄的不同而有所不同。使用双能X线吸收法测量了210名年龄为21岁(范围为12-40岁)的患有神经性厌食症的女性的第三腰椎和股骨颈的骨大小和vBMD。结果以年龄特异性的标准差表示(均值±标准误差)。骨宽取决于神经性厌食症的发病年龄;当神经性厌食症发病时(1)在15岁之前,椎体和股骨颈宽度的缺陷没有差异(分别为-0.77±0.27 SD和-0.55±0.17 SD);(2)在15-19岁之间,椎体宽度的缺陷(-0.95±0.16 SD)是股骨颈宽度缺陷(-0.28±0.14 SD;比较缺陷时p<0.05)的三倍,(3)在19岁之后,椎体宽度的缺陷(-0.49±0.26 SD;p=0.05)是早期发病神经性厌食症妇女的一半。在股骨颈没有观察到骨宽的缺陷。椎体和股骨颈vBMD的缺陷与神经性厌食症的发病年龄无关,但随着神经性厌食症持续时间的增加而增加,椎体vBMD比股骨颈低约0.5 SD。我们推断,受疾病暴露时区域的成熟发育和疾病持续时间是决定神经性厌食症特异性缺陷的部位、大小和类型的因素。成年期的骨脆弱性部分在生长期间建立,由于骨大小和vBMD的减少所致。