University of Iowa, Iowa City, IA, USA.
Pediatr Res. 2022 May;91(6):1606-1615. doi: 10.1038/s41390-021-01562-y. Epub 2021 May 10.
Associations among body composition measures have been limited to cross-sectional analyses of different subjects. We identified cross-sectional relationships between body mass index (BMI) and other body composition measures and predicted body composition measures from BMI throughout childhood and adolescence.
BMI was calculated and % body fat (%BF), fat mass index (FMI), and fat-free mass index (FFMI) were measured using dual-energy x-ray absorptiometry at ages 5, 9, 11, 13, 15, and 17 years in a birth cohort (n = 629). Sex-specific body composition measures were calculated for BMI-for-age percentiles; associations between BMI and body composition measures were characterized; and body composition measures were predicted from BMI.
%BF, FMI, and FFMI generally increased with BMI-for-age percentiles at each age. Correlations between BMI and %BF or FMI were generally higher at BMI-for-age percentiles ≥95% than for lower BMI-for-age percentiles. Correlations between BMI and FFMI were generally higher for participants at very low and very high BMI-for-age percentiles than at moderate BMI-for-age percentiles. Age- and sex-specific predictions from BMI are provided for %BF, FM, and FFMI.
Sex-specific body composition measures throughout childhood and adolescence are presented. BMI is a better indicator of adiposity at higher than at lower BMI values.
Sex-specific body composition measures throughout childhood and adolescence are described. % BF, FMI, and FFMI generally increased with BMI-for-age percentiles for both sexes throughout childhood and adolescence. BMI is a better indicator of adiposity at higher BMI levels than at lower BMI values throughout childhood and adolescence.
人体成分测量指标之间的关联仅限于对不同受试者的横断面分析。我们确定了体重指数（BMI）与其他人体成分测量指标之间的横断面关系，并预测了 BMI 从儿童期到青春期的人体成分测量指标。
在一个出生队列中（n=629），在 5、9、11、13、15 和 17 岁时，使用双能 X 射线吸收法计算 BMI 和体脂肪百分比（%BF）、脂肪量指数（FMI）和去脂体重指数（FFMI）。为 BMI-年龄百分位计算了性别特异性的人体成分测量指标；描述了 BMI 与人体成分测量指标之间的关系；并从 BMI 预测人体成分测量指标。
%BF、FMI 和 FFMI 通常随着 BMI-年龄百分位的增加而增加。BMI 与 %BF 或 FMI 的相关性在 BMI-年龄百分位≥95%时通常高于 BMI-年龄百分位较低时。BMI 与 FFMI 的相关性在 BMI-年龄百分位非常低和非常高的参与者中通常高于 BMI-年龄百分位适中的参与者。为 %BF、FM 和 FFMI 提供了年龄和性别特异性的 BMI 预测值。
提出了整个儿童期和青春期的性别特异性人体成分测量指标。在较高的 BMI 值时，BMI 是肥胖的更好指标。
描述了整个儿童期和青春期的性别特异性人体成分测量指标。在整个儿童期和青春期，男女的 %BF、FMI 和 FFMI 通常随着 BMI-年龄百分位的增加而增加。在整个儿童期和青春期，BMI 是肥胖的更好指标，而不是在 BMI 值较低时。
