Bielemann Renata M, Gonzalez Maria Cristina, Barbosa-Silva Thiago Gonzalez, Orlandi Silvana Paiva, Xavier Mariana Otero, Bergmann Rafaela Bülow, Assunção Maria Cecília Formoso
Post Graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil; Nutrition College, Federal University of Pelotas, Pelotas, Brazil.
Post Graduate Program in Health and Behavior, Catholic University of Pelotas, Pelotas, Brazil.
Nutrition. 2016 Apr;32(4):441-6. doi: 10.1016/j.nut.2015.10.009. Epub 2015 Oct 30.
This study aimed to develop and validate equations to estimate body fat based on anthropometric measurements of subcutaneous fat thickness (SFT) and muscle thickness (MT) measured by A-mode ultrasound (BodyMetrix) in Brazilian adults.
Individuals (n = 206) underwent air-displacement plethysmography for body composition assessment. Arm, thigh, and calf circumferences were also obtained. SFT from triceps, biceps, subscapular, abdominal, thigh, and calf regions and MT from triceps, biceps, thigh, and calf regions were measured by BodyMetrix. Prediction equations were developed by stepwise multiple linear regression using the circumferences, weight, height, SFT, and MT. Lin's concordance correlation coefficient, mean difference, and 95% limits of agreement (95% LOA) were assessed in apparent and internal validity.
The prediction equation for whole-body fat for men included thigh circumference, triceps and thigh SFT, biceps MT, weight, and height. The equation for women included age, calf circumference, abdominal and calf SFT, weight, and height. The prediction equation overestimated men's whole-body fat by 0.5 percentual points, in average, and the lower and upper 95% LOA were -6.8% and 7.7%, respectively. For women, the prediction equation overestimated whole-body fat by 0.1 percentual points, in average. Lower and upper 95% LOA were -6.5% and 6.7%, respectively. Optimism-adjusted results using 500 repetitions with same size samples have shown similar results. Body fat extremes did not influence the whole-body fat estimation.
BodyMetrix A-mode ultrasound, in association with selected conventional anthropometric measurements, proved to be a reliable tool for the estimation of body fat percentage.
本研究旨在开发并验证基于通过A型超声（BodyMetrix）测量的皮下脂肪厚度（SFT）和肌肉厚度（MT）的人体测量数据来估算巴西成年人身体脂肪的方程。
206名个体接受了空气置换体积描记法以评估身体成分。同时还测量了手臂、大腿和小腿的周长。通过BodyMetrix测量三头肌、二头肌、肩胛下、腹部、大腿和小腿区域的SFT以及三头肌、二头肌、大腿和小腿区域的MT。使用周长、体重、身高、SFT和MT通过逐步多元线性回归建立预测方程。在表面效度和内部效度中评估了林氏一致性相关系数、平均差异和95%一致性界限（95% LOA）。
男性全身脂肪的预测方程包括大腿周长、三头肌和大腿SFT、二头肌MT、体重和身高。女性的方程包括年龄、小腿周长、腹部和小腿SFT、体重和身高。该预测方程平均高估男性全身脂肪0.5个百分点，95% LOA下限和上限分别为-6.8%和7.7%。对于女性，预测方程平均高估全身脂肪0.1个百分点。95% LOA下限和上限分别为-6.5%和6.7%。使用相同大小样本进行500次重复的乐观度调整结果显示了相似的结果。身体脂肪极端值不影响全身脂肪估计。
BodyMetrix A型超声与选定的传统人体测量数据相结合，被证明是估算身体脂肪百分比的可靠工具。
