IRCCS Istituto Auxologico Italiano, Division of Rehabilitation Medicine, Research Lab in Biomechanics and Rehabilitation, San Giuseppe Hospital, Piancavallo (VB), Italy.
University of Bahrain, Department of Mathematics, College of Science, Sakhir Campus P. O. Box 32038, Kingdom of Bahrain.
Clin Nutr. 2021 Jun;40(6):3973-3981. doi: 10.1016/j.clnu.2021.04.033. Epub 2021 Apr 28.
BACKGROUND & AIMS: Obesity is characterized by fat mass excess (FM), extra cellular water increase (ECW) and, with ageing, decrease in fat free mass (FFM). The validity of body impedance analysis (BIA) in patients with mild to severe obesity is still debated. The purpose of this study is to describe the Resistance (Rz) and Reactance (Xc) values obtained by Body Impedance Analysis (BIA) in a wide cohort of Italian patients with mild to severe obesity. The secondary endpoint is to describe the resulting body composition values (as percentage and indexes) in this population.
The study enrolled adult in-patients with mild to severe obesity (classified with class I, II and III obesity) undergoing clinical care rehabilitation program for obesity complications and weight loss. BIA values were grouped by sex, BMI and age classes.
A total of 8303 patients with obesity, aged 18 to 90 y, were studied. The Resistance (Rz) and Reactance (Xc) were reported by sex, age and BMI classes. In women and men both, the phase angle (PhA) decreases with increasing BMI (kg/m) and the resulting BIA vector was significantly shifted. The FM index (FMI) was higher (p < 0.0001) in women while FFM index (FFMI) was higher in men (p < 0.0001) and significantly associated with BMI. FFMI decreased with age in both sex (p < 0.0001). Skeletal mass (SM) presents a progressive reduction in relation to age and gender both.
The present BIA-based body composition analysis in a wide cohort of mild to severe obese patients revealed a significantly decreased Rz and Xc values with a consequent significant decrease of PhA in a BMI-dependent manner. The body compartments estimation with available equations was BMI, sex and age dependent. These observational results could be the basis for the development of new equations adapted for patients suffering from obesity.
肥胖的特征是体脂肪量过多（FM）、细胞外液增加（ECW），随着年龄的增长，还会出现去脂体重（FFM）减少。身体阻抗分析（BIA）在轻度至重度肥胖患者中的有效性仍存在争议。本研究的目的是描述在广泛的意大利轻度至重度肥胖患者队列中，通过身体阻抗分析（BIA）获得的电阻（Rz）和电抗（Xc）值。次要终点是描述该人群中得出的身体成分值（百分比和指数）。
本研究纳入了接受肥胖并发症和减肥临床护理康复计划的轻度至重度肥胖（分为 I 类、II 类和 III 类肥胖）的成年住院患者。BIA 值按性别、BMI 和年龄组进行分组。
共研究了 8303 名年龄在 18 至 90 岁之间的肥胖患者。报告了按性别、年龄和 BMI 分组的电阻（Rz）和电抗（Xc）。在女性和男性中，相位角（PhA）随着 BMI（kg/m）的增加而降低，并且 BIA 向量明显移位。FM 指数（FMI）在女性中更高（p<0.0001），而 FFM 指数（FFMI）在男性中更高（p<0.0001），并与 BMI 显著相关。FFMI 在两性中均随年龄增长而降低（p<0.0001）。骨骼质量（SM）也呈现出与年龄和性别相关的逐渐减少。
本研究对广泛的轻度至重度肥胖患者进行了基于 BIA 的身体成分分析，结果显示 Rz 和 Xc 值显著降低，PhA 呈 BMI 依赖性显著降低。可用方程估计的身体腔室与 BMI、性别和年龄有关。这些观察结果可能是为肥胖患者开发新的适应性方程的基础。
