Takahashi Y, Minamitani K, Kobayashi Y, Minagawa M, Yasuda T, Niimi H
Department of Pediatrics, Chiba University School of Medicine, Japan.
J Clin Endocrinol Metab. 1996 Mar;81(3):1248-53. doi: 10.1210/jcem.81.3.8772607.
Since the attainment of higher bone mineral density (BMD) is a crucial strategy in preventing age-related bone loss and consequent fracture, we determined when bone mass of the lumbar spine (L2-L4) (g/cm2) and femoral neck (g/cm2) reaches its peak in healthy Japanese subjects and examined the influence of early exposure to estrogen and estrogen deficiency on BMD. We also determined the volumetric BMD, termed bone mineral apparent density (BMAD), of the lumbar spine and femoral neck. Using dual-energy x-ray absorptiometry (DXA) (Hologic QDR-1000), we measured BMD of both the lumbar spine and the femoral neck in 31 healthy children aged 2-11 yr, 269 children (138 males and 131 females) aged 13-19 yr, 12 men and 12 women aged 20-34 yr as adult controls, 11 patients with female central sexual precocity, and 3 patients with female primary hypogonadism. Because the densitometric data obtained from DXA are strongly influenced by the size of the bone in growing subjects, the volumetric BMAD (g/cm3) of the vertebral cube (L2-L4) and femoral neck were determined: BMAD (g/cm3) = BMD (g/cm2)/square root of scanned area (cm2) for the lumbar spine and by BMAD = BMD/width for the femoral neck. The BMD, both lumbar spine and femoral neck, nearly reached its peak at age 14.5-15 yr in girls and 16.5-17 yr in boys when compared with adult normal values. The difference in this age between sexes is identical to the difference in age at sexual maturation. BMD in patients with sexual precocity was high compared to age-matched controls, whereas patients with primary hypogonadism showed lower lumbar apparent BMD, and the increase in lumbar BMAD (g/cm3) was noted after the progression of puberty in healthy children, probably suggesting the importance of sex steroids in the increase of BMD and lumbar BMAD in both sexes. The girls with earlier menarche showed higher lumbar BMD at age 18 and 19 yr. For the femoral BMAD, there was no significant relationship between this value and age in girls. We conclude that peak bone mass is mainly achieved by late adolescence in Japanese as in Caucasians and that pubertal progression and probably estrogen itself play a crucial role in accumulation of bone mass in females.
由于获得更高的骨矿物质密度（BMD）是预防与年龄相关的骨质流失及随之而来的骨折的关键策略，我们确定了健康日本受试者腰椎（L2-L4）（g/cm²）和股骨颈（g/cm²）的骨量何时达到峰值，并研究了早期暴露于雌激素和雌激素缺乏对BMD的影响。我们还测定了腰椎和股骨颈的体积骨密度，即骨矿物质表观密度（BMAD）。使用双能X线吸收法（DXA）（Hologic QDR-1000），我们测量了31名2-11岁健康儿童、269名13-19岁儿童（138名男性和131名女性）、作为成人对照的12名20-34岁男性和12名女性、11名女性中枢性性早熟患者以及3名女性原发性性腺功能减退患者的腰椎和股骨颈BMD。由于从DXA获得的密度测量数据受生长中受试者骨骼大小的强烈影响，因此确定了椎体立方（L2-L4）和股骨颈的体积BMAD（g/cm³）：腰椎的BMAD（g/cm³）=BMD（g/cm²）/扫描面积（cm²）的平方根，股骨颈的BMAD=BMD/宽度。与成人正常值相比，女孩腰椎和股骨颈的BMD在14.5-15岁时几乎达到峰值，男孩在16.5-17岁时达到峰值。两性在这个年龄的差异与性成熟年龄的差异相同。性早熟患者的BMD高于年龄匹配的对照组，而原发性性腺功能减退患者的腰椎表观BMD较低，健康儿童在青春期进展后腰椎BMAD（g/cm³）增加，这可能表明性类固醇在两性BMD和腰椎BMAD增加中具有重要作用。月经初潮较早的女孩在18岁和19岁时腰椎BMD较高。对于股骨BMAD，女孩的该值与年龄之间无显著关系。我们得出结论，与白种人一样，日本人群的峰值骨量主要在青春期后期实现，青春期进展以及可能雌激素本身在女性骨量积累中起关键作用。
