深圳市13～15岁正常少年超声骨密度特征(英文)

Measurement of bone mineral density with ultrasound in healthy teenagers at the age of 13 to 15 years in Shenzhen city

背景：应用超声骨密度仪检测骨密度缺乏定量超声独立使用的临床指征标准。 目的：了解深圳地区13～15岁不同性别少年超声骨密度状况；建立该年龄段少年超声骨密度正常参考值。 设计：横断面调查。 单位：深圳市龙岗区人民医院超声科。 对象：选择2003-04-12深圳市二所中学的13～15岁学生健康志愿者158例，排除曾发生骨折者和6个月内服用激素等影响骨代谢药物者，男90例，女68例。女性分为无月经初潮组和有月经初潮组。 方法：采用美国SAHARA超声骨密度仪，开机后用标准体模校正通过(精确性误差<1％，准确性误差为3％)，测定所有受试者左足跟骨密度值(g／cm^2)，足跟置于探头间，用定位附件调节固定位置，用同一身高、体重计，测量所有受检者的体质量(kg)、身高(cm)。 主要观察指标：①13～15岁正常少年身高、体质量及跟骨骨密度测量结果。②13～15岁不同性别的正常少年骨密度测量结果。③13～15岁正常女性无月经初潮者和有月经初潮者骨密度分布。 结果：①13～15岁正常少年身高、体质量及跟骨骨密度测量结果：14岁身高增长速度是15岁少年的2倍多(4．705cm／年，2．096cm／年)，骨密度的平均增长率14岁较13岁为负增长，15岁较14岁增长10．8％；体质量与骨密度呈正相关性(γ=0．820，P<0．01)。②13～15岁不同性别的正常少年骨密度测量结果：女性高于男性[13岁(0．542±0．117)比(0．528±0．086)g／cm^2，14岁(0．508±0．108)比(0．487±0．079)g／cm^2，15岁(0．609±0．234)比(0．501±0．225)g／cm^2]③13～15岁正常女性无月经初潮者和有月经初潮者骨密度分布：有月经初潮者高于无月经初潮者(P<0．001)。 结论：①13～15岁少年足跟部骨密度与性别和身高增长快慢有关。②体质量对骨密度的影响比身高对骨密度的影响大。③有月经初潮女性因雌激素增加有促进骨密度增高作用。

BACKGROUND： Bone mineral density（BMD） measured with ultrasound bone densitometer lacks the criteria for clinical signs of independent application of quantitative ultrasound（QUS）. OBJECTIVE： To investigate BMD of teenagers in either gender at the age of 13 to 15 years in Shenzhen city so as to provide normal referenced values of ultrasound-evaluated BMD in teenagers at the age mentioned above. DESIGN： A cross-sectional investigation. SETTING： Department of Ultrasound, People＇s Hospital of Longgang District, Shenzhen. PARTICIPANTS： Totally 158 healthy volunteers（male 90 and female 68）at the age of 13 to 15 years were selected from two middle schools in Shenzhen City on April 12, 2003 after excluding those who had affected with fracture or had taken the drugs influencing bone metabolism such as hormones 6 months before our investigation. The female ones were divided into pre-menarche and post-menarche groups. METHODS： All the patients were corrected based on the normal physical norm（error of truth lower than 1% and accuracy equal to 3%） after an ultrasound bone densitometer （made in America） was started up. The left heels of the subjects were placed between detecting heads, and the fixing position was adjusted with location appurtenances to measure the BMD of left heels （g/cm2）. The body mass and body height were measured in all the teenagers with the same weighing and height machines. MAIN OUTCOME MEASURES： ①Body height, body mass and heel BMD of healthy teenagers at the age of 13 to 15 years; ②BMD of the healthy teenagers in either gender at the age of 13 to 15 years; ③Distribution of BMD in pre-menarche and post-menarche female teenagers at the age of 13 to 15 years. RESULTS： ①Body height, body mass and heel BMD of healthy teenagers at the age of 13 to 15 years： The increasing speed of body height in teenagers at 14 years of age is over two times as fast as that in those at 15 years of age（4.705 cm per year vs 2.096 cm per year）. The average growth rate of BMD in teenagers at the age of 14 years was in a negative growth as compared with that in those at the age of 13 years, and it was increased by 10.8% in teenagers of 15 years old as compared with that in those of 14 years. The body mass was in a negative correlation with BMD （r=0.820, P 〈 0.001）. ②BMD of the healthy teenagers in either gender at the age of 13 to 15 years： The BMD was higher in females than in males [（0.542±0.117） g/cm^2 vs （0.528±0.086） g/cm^2 for those of 13 years old,（0.508±0.108） g/cm^2 vs （0.487±0.079） g/cm^2 for those of 14 years old,（0.609±0.234） g/cm^2 vs （0.501±0.225） for those of 15 years]③Distribution of BMD in pre-menarche and post-menarche female teenagers at the age of 13 to 15 years： It was significantly higher in the pre-menarche ones than in post-menarche ones （P 〈 0.001）. CONCLUSIONS： ①The heel BMD in the teenagers at the age of 13 to 15 years is related to their genders and the increasing speed of their body height. ②Body mass has more influence on BMD than body height does.③Increase of estrogen in post-menarche females can promote the increase of BMD.