Saboor Mohsen, Samadani Mahsa, Zare Javid Ahmad, Kazemi Parvaneh, Sharifat Morteza, Bavi Behbahani Hossein, Cheraghian Bahman
Department of Nutrition, School of Health, Iran University of Medical Sciences, Tehran, Iran.
Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Iran J Public Health. 2023 Feb;52(2):389-398. doi: 10.18502/ijph.v52i2.11892.
Estimating Fat-Free Mass (FFM) is an integral part of Body composition measurements, so obtaining an accurate estimation for evaluating FFM is critical for researchers and specialists. We aimed to develop and validate a simple equation for predicting FFM in the adult population.
Participants were 1996 adults (1085 men and 911 women), and 18 to 69 years old from Ahvaz City, southern Iran. They were randomly divided into the derivation (n=1396) and the validation (n=600) groups with no significant differences from Jan 2018 to Feb 2020. FFM was measured by Bioelectrical Impedance Analyzer (BIA) (InBody 770©; Biospace, Seoul, South Korea). Based on the demographic variables retrieved from the Derivation group, 8 FFM predictive equations were developed using multiple regression; finally, the most accurate model (using the coefficient of determination (R2)) was chosen and then validated on the Validation group for more evaluation.
The best equation derived from demographic characteristics was: "FFM= 0.28 × Weight (kg) + 0.57×Height (cm)+7.35×Sex (M=1, F=0)+0.03×Age (years)-70.61"; where sex = 1 for male and 0 for female. R=0.94, R2=0.89, standard error of the estimate=4.04 kg.
Our developed and cross-validated anthropometric prediction equation for fat-free mass estimation using BIA attained a high coefficient of determination, a low standard error of the estimate, and the lowermost coefficient of variation. Predictive equations may be reliable and valuable alternative methods for the clinical evaluation of fat-free mass in the adult population.
估算去脂体重（FFM）是身体成分测量的一个重要组成部分，因此获得准确的估算值对于评估FFM对研究人员和专家来说至关重要。我们旨在开发并验证一个用于预测成年人群FFM的简单方程。
研究对象为1996名年龄在18至69岁之间的伊朗南部阿瓦士市成年人（1085名男性和911名女性）。从2018年1月至2020年2月，他们被随机分为推导组（n = 1396）和验证组（n = 600），两组之间无显著差异。使用生物电阻抗分析仪（BIA）（InBody 770©；韩国首尔Biospace公司）测量FFM。基于从推导组获取的人口统计学变量，通过多元回归开发了8个FFM预测方程；最后，选择最准确的模型（使用决定系数（R2）），然后在验证组上进行验证以作进一步评估。
从人口统计学特征得出的最佳方程为：“FFM = 0.28×体重（kg） + 0.57×身高（cm） + 7.35×性别（男性 = 1，女性 = 0） + 0.03×年龄（岁） - 70.61”；其中男性性别 = 1，女性性别 = 0。R = 0.94，R2 = 0.89，估计标准误差 = 4.04 kg。
我们开发并交叉验证的用于使用BIA估算去脂体重的人体测量学预测方程具有较高的决定系数、较低的估计标准误差和最低的变异系数。预测方程可能是成年人群去脂体重临床评估的可靠且有价值的替代方法。
