DXA测量人体质量与自测体重的差异分析

The differential analysis of DXA measurement of body mass and self-test body weight

目的体重在双能X线吸收法(dual-energy X-ray absorptiometry,DXA)诊断骨质疏松症方面有重要作用,由于季节不同穿着衣物重量的差异,可能对体重的结果有影响,本研究回顾性分析应用DXA测量人体质量与自测体重之间的差异。方法观察200例样本,以体重与体质量的差值(difference of body weight and body mass,DBWM)为主要观察指标,体质量通过DXA测量人体全身获得,体重通过体重秤直接测量,分析季节、性别因素对DBWM的影响。结果测量的体重明显大于体质量(t=8.432,P=6.846×10-15);体重与体质量在夏季基本一致(t=-0.376,P=0.712);DBWM在不同季节有不同分布(F=3.662,P=0.013),夏季与其余季节比较均有明显差异(与春季、秋季、冬季比较分别为:P=0.003、P=0.013、P=0.002);DBWM的分布与性别无关(t=0.554,P=0.581);剔除15例奇异值样本之后,体重与体质量的差异仍存在(t=14.282,P=4.951×10-151)。结论 1直接测量的体重明显大于DXA测量的体质量,不同季节对体重与体质量的差异有影响,由于夏季穿着衣物较少,对体重的影响也较小,建议在测量体重时穿着较少的衣物,或者扣除衣物的重量。2对于无法直接测量体重的样本,建议用DXA测量全身从而获得更准确的体质量。

Objective Weight plays an important role in the diagnosis of osteoporosis using dual-energy X-ray absorptiometry（ DXA）. The weight of different dress during different season may affect the measurement. This study retrospectively analyzes the differences between DXA measurement of body mass and self-test body weight. Methods The difference of body weight and body mass（ DBWM） of 200 cases was observed to analyze seasonal and gender factors on DBWMimpact. Body mass was measured using DXA and body weight was obtained by direct measurement using weight scales. Results Body weight measured was significantly greater than body mass（ t = 8. 432,P = 6. 846 × 10- 15）. Weight and body mass in the summer were consistent（ t =-0. 376,P = 0. 712）. DBWMin different seasons had different distribution（ F = 3. 662,P = 0. 013）. DBWMin the summer was significantly different comparing to that in the rest seasons（ P = 0. 003,0. 013,and 0. 002 comparing to that in the spring,autumn,and winter,respectively）. DBWMdistribution was unrelated to gender（ t = 0. 554,P = 0. 581）. The difference between weight and body mass still existed after excluding 15 extreme cases（ t = 14. 282 P = 4. 951 × 10- 151）. Conclusion 1） The value of body weight obtained by direct measurement using weight scales is significantly greater than that of body mass measured by DXA.DBWMis different in different seasons. The effect on weight in the summer is less due to less wearing. It is recommended that dress less or deduct weight of the cloth when measuring body weight. 2） It is recommended to use DXA measurement of body mass for those whose body weight cannot be measured directly.