De Palo T, Messina G, Edefonti A, Perfumo F, Pisanello L, Peruzzi L, Di Iorio B, Mignozzi M, Vienna A, Conti G, Penza R, Piccoli A
Division of Pediatric Nephrology and Dialysis, "Giovanni XXIII" Hospital, Bari, Italy.
Nutrition. 2000 Jun;16(6):417-24. doi: 10.1016/s0899-9007(00)00269-0.
The purpose of this study was to determine the reference, bivariate, and tolerance intervals of the whole-body impedance vector in Italian children. This was a cross-sectional, multicenter study, and participants were chosen from the general school population. The impedance vector (standard, tetrapolar analysis at 50-kHz frequency) was measured in 3110 subjects, ages 2 to 15 y, and 2044 healthy children (1014 male and 1030 female) with weight and height within the 95th percentile were selected for the analysis (resistance-reactance graph method). The age-specific 95% confidence intervals of mean vectors and the 95%, 75%, and 50% tolerance intervals for individual vector measurements were plotted using resistance and reactance components standardized by the subject's height. Mean vectors from both sexes with separate 95% confidence ellipses were considered as representative of eight different age groups, from 2 to 13 y. There was a statistically significant sex effect on vector distribution from boys and girls in the age group of 14 to 15 y. The impedance vector distribution of children was also compared with healthy adult subjects (354 male and 372 female, age 15 to 85 y). There was a progressive, statistically significant vector shortening from age 2 to 15 y toward the adults' vector position. In conclusion, we established the trajectory followed by the mean impedance vector in children over ages 2 to 15 y and also obtained the reference, bivariate, and 95%, 75%, and 50% tolerance intervals of the impedance vector by age for healthy children, with which the vectors from children with altered body composition can be tested.
本研究的目的是确定意大利儿童全身阻抗向量的参考区间、双变量区间和容许区间。这是一项横断面多中心研究，参与者选自普通学校人群。对3110名年龄在2至15岁的受试者进行了阻抗向量测量（50 kHz频率下的标准四极分析），并选取了2044名体重和身高在第95百分位数以内的健康儿童（1014名男性和1030名女性）进行分析（电阻-电抗图法）。使用根据受试者身高标准化的电阻和电抗分量绘制了平均向量的年龄特异性95%置信区间以及个体向量测量的95%、75%和50%容许区间。将来自男女两性且带有单独95%置信椭圆的平均向量视为2至13岁八个不同年龄组的代表。在14至15岁年龄组中，男孩和女孩的向量分布存在统计学上显著的性别效应。还将儿童的阻抗向量分布与健康成人受试者（354名男性和372名女性，年龄15至85岁）进行了比较。从2岁到15岁，向量逐渐向成人向量位置缩短，差异具有统计学意义。总之，我们确定了2至15岁儿童平均阻抗向量的轨迹，并获得了健康儿童按年龄划分的阻抗向量参考区间、双变量区间以及95%、75%和50%容许区间，可据此对身体成分改变的儿童的向量进行检验。
