Exercise and Health Laboratory, CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz-Quebrada 1499-002, Portugal.
California Pacific Medical Center, Research Institute, San Francisco, CA 94109, USA.
Clin Nutr. 2024 Jan;43(1):154-162. doi: 10.1016/j.clnu.2023.11.039. Epub 2023 Nov 30.
BACKGROUND & AIMS: It is not yet known whether regional bioelectrical impedance (BIA) phase angle (PhA) may be informative of different types of strength performed by the lower and upper limbs, independently of lean soft tissue mass (LSTM). Using a sample of healthy adults, we aimed to examine the association and relevance of regional PhA relative to isometric and isokinetic strength of each limb.
A total of 57 participants (32.7 ± 12.9 years; 24.7 ± 3.5 kg/m) were included in the present investigation. Regional raw BIA variables were determined using a phase-sensitive BIA device. Dual-energy X-ray absorptiometry was used to evaluate LSTM. Absolute isometric and isokinetic (i.e., 60°/s and 180°/s) strength of each limb (extension and flexion) was assessed using an isokinetic dynamometer and used to calculate relative strength.
In absolute strength, only dominant leg PhA was associated with isometric extension strength (β = 0.283) and isokinetic 180°/s flexion strength (β = 0.354), regardless of LSTM (p < 0.05). In relative strength, a significant association of regional PhA was found for dominant arm flexion isometric strength (β = 0.336), and non-dominant arm and dominant leg extension isometric strength (β = 0.377, β = 0.565, respectively; p < 0.05), independently of LSTM. Similarly, for isokinetic 180°/s strength, regional PhA significantly explained the variance in the relative strength of both arms and dominant leg (β = 0.350 to 0.506), regardless of LSTM (p < 0.05). Relative isokinetic 60°/s strength was not consistently associated with regional PhA (p ≥ 0.05).
Regional PhA significantly explained relative (isometric and 180°/s isokinetic strength of both arms and dominant leg), but not absolute muscle strength, independently of regional LSTM. Thus, after accounting for body size, regional PhA seems to have its own characteristics that explain relative strength independently of LSTM.
目前尚不清楚区域生物电阻抗（BIA）相位角（PhA）是否可以提供有关下肢和上肢进行的不同类型力量的信息，而与瘦体组织质量（LSTM）无关。使用健康成年人样本，我们旨在检查区域 PhA 与每个肢体的等长和等速力量的相关性和相关性。
本研究共纳入 57 名参与者（32.7±12.9 岁；24.7±3.5kg/m）。使用相位敏感 BIA 设备确定区域原始 BIA 变量。双能 X 射线吸收法用于评估 LSTM。使用等速测力计评估每个肢体（伸展和屈曲）的绝对等长和等速（即 60°/s 和 180°/s）强度，并用于计算相对强度。
在绝对强度方面，只有优势腿 PhA 与等长伸展强度（β=0.283）和等速 180°/s 屈曲强度（β=0.354）相关，与 LSTM 无关（p<0.05）。在相对强度方面，区域 PhA 与优势臂等长屈曲强度（β=0.336）以及非优势臂和优势腿等长伸展强度（β=0.377，β=0.565，分别）显著相关，与 LSTM 无关。同样，对于 180°/s 的等速强度，区域 PhA 显著解释了双臂和优势腿相对强度的变化（β=0.350 至 0.506），与 LSTM 无关（p<0.05）。相对等速 60°/s 强度与区域 PhA 无明显相关性（p≥0.05）。
区域 PhA 显著解释了相对（等长和 180°/s 等速强度），但不是绝对肌肉力量，与区域 LSTM 无关。因此，在考虑身体大小后，区域 PhA 似乎具有其自身的特征，可以独立于 LSTM 解释相对强度。
