Can Phase Angle Be Associated With Muscle Strength in Healthy Male Army Cadets?

Mil Med. 2022 Jan 25:usac007. doi: 10.1093/milmed/usac007. Online ahead of print.

Abstract

Introduction: Phase angle (PhA) determined by bioelectrical impedance (BIA) is related to body fluid balance and cell membrane integrity. Handgrip strength (HGS) is used to assess muscle strength and as an indicator of health. We aimed to determine the relationship between PhA and HGS in healthy young males and to verify whether this relationship is dependent on body components.

Materials and methods: Hundred and sixty-three healthy male army cadets (18.8 ± 0.6 years old) participated in the study. PhA was determined by BIA, HGS was assessed by a hydraulic dynamometer, and dual-energy X-ray absorptiometry determined: fat mass (FM), bone mineral content (BMC), and lean soft tissue (LST). Participants were divided according to the PhA tertile (first tertile: PhA < 7.14°, second tertile: 7.14° ≤ PhA < 7.83°, and third tertile: PhA ≥ 7.83°).

Results: Youth from the first tertile of PhA had lower BMC (2.8 kg vs. 3.0 kg and vs. 3.1 kg) and LST (51.7 vs. 53.8 kg and vs. 57.6 kg) compared to youth from the second and third tertile of PhA (P < .001), respectively. Additionally, lower HGS (83.0 kg vs. 93.1 kg) was found in the first tertile compared to the third tertile of PhA (P < .001). PhA explained 3% of the HGS variation (R2 = 0.029), while LST and BMC explained 39% (R2 = 0.385) and 22% (R2 = 0.221), respectively. Furthermore, the correlation between PhA and HGS was dependent on LST (P = .567) and BMC (P = .182).

Conclusion: In this sample, PhA showed a small relationship with HGS, remaining dependent on BMC and LST values. These results reinforce the importance of maintaining a physically active lifestyle with great lean mass and muscle strength values.