生物电阻抗法与双标水稀释法在人体成分测定中的应用比较

目的 用双标水稀释法验证目前在我国广泛应用的体成分测定方法--生物电阻抗法的准确性.方法 从白求恩军医学院某中队150名学员中根据体质指数(BMI)等指标筛选出16名学员作为受试对象,试验期为14 d,试验期间学员集中管理,统一食宿.试验第1天受试者服用双标水,收集服用前及服用后2 h、4 h、6 h、8 h及第2至第14天的尿液,用质谱分析的方法,得到受试者2H、18O的消除曲线,从而获得受试者的体成分数据.与此同时,从试验第1天开始,每天晚餐后3 h用生物电阻抗仪对每位受试者进行体成分的测定.最后,将2种方法获得的体成分数据加以比对.结果 经统计学分析,生物电阻抗法与双标水稀释法获得的体成分参数值差异无统计学意义,而且高度相关,两种方法测得的总体水、瘦体重、体脂及体脂百分比的相关系数分别为0.556,0.556,0.817,0.606,具有统计学意义.结论 应用生物电阻抗法测定中国人体成分具有较高的准确性.

Comparison of bioelectrical impedance analysis and isotope dilution method in assessment of body composition

OBJECTIVE: To determine the validity of bioelectrical impedance analysis (BIA) in measuring body composition and to compare with the reference stable isotope dilution method. METHODS: According to the data from 150 students of Bethune Military Medical College, 16 female young adults with normal BMI were selected as the participants. The experimental period was 14 days. During the experimental period, the subjects were centralized on management. At the first day of the period, double labeled water was given to the subjects orally. The urine collection time-points were 2h, 4h, 6h, 8h and the 2nd to 14th day after the administration of isotope dose. All isotope measurements were made by using an isotope ratio mass spectrometer. From the isotope curing curve, the indexes of body composition were gained. At the same time, the body compositions were also measured by using BIA method every day (3 hours after dinner). The paired t test and Pearson correlations were used to measure the significance and the degree of correlation between the measurements determined by using the two methods. RESULTS: There were no significant differences between the measurements determined by using the two methods. TBW, FFM, BF and BF% measured with the BIA method were significantly correlated with those measured by using the isotope method (r = 0.556, 0.556, 0.817 and 0.606 respectively). CONCLUSION: BIA might provide an accurate and reliable assessment in body composition of the healthy Chinese adults.