Hashizume Naoki, Sakamoto Saki, Yoshida Motomu, Kurahachi Tomohiro, Tsuruhisa Shiori, Higashidate Naruki, Masui Daisuke, Koga Yoshinori, Kaji Tatsuru
Pediatric Surgery, Kurume University School of Medicine, Kurume, JPN.
Cureus. 2025 May 15;17(5):e84192. doi: 10.7759/cureus.84192. eCollection 2025 May.
Bioelectrical impedance analysis (BIA) is an attractive method for measuring the fat-free mass (FFM) and fat mass (FM) in adults. Although BIA is not typically performed in young children, previously published prediction equations for BIA in young children have been used recently. The present study evaluated the relationship between age, sex, and body composition in BIAs of young children.
This study is a retrospective cross-sectional analysis. All patients weighing >8 kg and 12-100 months old were included in the study. The body composition values in the BIA (FFM, FM, and phase angle (PhA)) were calculated. A multiple linear regression analysis for the body composition values in the BIA was used with the variables of age (months) and sex, as well as a constant.
A total of 147 patients (86 boys and 61 girls) with a median age of 47 months were enrolled. Using multiple regression analyses, the FFM equation included the age, sex, and a constant (FFM (kg) = 0.128 × age + 0.391 × sex [male = 1, female = 0] + 6.378 [R = 0.911]). The equations for the FM and PhA included the age and a constant (FM (kg) =0.036 × age + 1.094 [R = 0.5068], PhA [°] = 0.021 × age + 3.533 [R = 0.482]).
The present study demonstrated that age and sex are significant predictors of body composition parameters in young children as measured by BIA. Specifically, FFM was strongly associated with both age and sex, while FM and PhA were moderately associated with age. The derived regression equations may serve as reference models for estimating body composition in pediatric populations using BIA.
生物电阻抗分析（BIA）是测量成年人瘦体重（FFM）和脂肪量（FM）的一种有吸引力的方法。虽然BIA通常不在幼儿中进行，但最近已使用先前发表的幼儿BIA预测方程。本研究评估了幼儿BIA中年龄、性别与身体成分之间的关系。
本研究为回顾性横断面分析。所有体重>8 kg且年龄在12 - 100个月的患者纳入研究。计算BIA中的身体成分值（FFM、FM和相位角（PhA））。对BIA中的身体成分值进行多元线性回归分析，变量包括年龄（月）、性别以及一个常数。
共纳入147例患者（86例男孩和61例女孩），中位年龄为47个月。通过多元回归分析，FFM方程包括年龄、性别和一个常数（FFM（kg）= 0.128×年龄 + 0.391×性别[男性 = 1，女性 = 0] + 6.378 [R = 0.911]）。FM和PhA的方程包括年龄和一个常数（FM（kg）= 0.036×年龄 + 1.094 [R = 0.5068]，PhA [°] = 0.021×年龄 + 3.533 [R = 0.482]）。
本研究表明，年龄和性别是通过BIA测量的幼儿身体成分参数的重要预测因素。具体而言，FFM与年龄和性别均密切相关，而FM和PhA与年龄呈中度相关。推导的回归方程可作为使用BIA估计儿科人群身体成分的参考模型。
