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ORIGINAL RESEARCH article

Front. Med.

Sec. Geriatric Medicine

Volume 12 - 2025 | doi: 10.3389/fmed.2025.1525569

This article is part of the Research TopicBioimpedance Analysis: Lifelong Health, Disease, and Sport ApplicationsView all 8 articles

Application of Levi's Muscle Index in Frailty Assessment: Comparison of Bioimpedance Measures Among Older Adults

Provisionally accepted
  • 1Institute of Exercise Physiology and Rehabilitation Science, College of Health Professions and Sciences, University of Central Florida, Orlando, Florida, United States
  • 2EMBRACE Lab, College of Nursing, University of Central Florida, Orlando, United States
  • 3Wearable Engineering and Assistive Robotics Lab, Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, United States
  • 4College of Medicine, University of Central Florida, Orlando, Florida, United States
  • 5Disability, Aging, and Technology Cluster, University of Central Florida, Orlando, United States
  • 6Department of Statistics & Data Science, College of Sciences, University of Central Florida, Orlando, Florida, United States

The final, formatted version of the article will be published soon.

Introduction: Frailty is prevalent among older adults and is characterized by reductions in physical function and muscle quality. Despite the emerging clinical utility of bioelectrical impedance analysis (BIA) and phase angle (PhA) as a bioimpedance index, little is known about how bioimpedance indices such as Levi's Muscle Index (LMI), reactance/height (Xc/Height), and resistance/height (R/Height), relate to physical function and frailty.Methods: This cross-sectional study examined 208 community-dwelling older adults (female, n = 183; age = 74.2 ± 6.9 years; BMI = 30.4 ± 6.4kg/m 2 ) to compare physical function measures and bioimpedance indices across frailty categories determined by the FRAIL questionnaire. PhA, LMI, Xc/Height, and R/Height were all assessed at 50 kHz using a direct segmental multi-frequency InBody s10 BIA device. Physical function was assessed using handgrip strength, postural sway, Timed-Up-and-Go, and the Short Physical Performance Battery. Data were analyzed using Spearman rho (ρ) and Pearson r correlation coefficients, and group differences were examined using Kruskal-Wallis H tests and one-way ANOVA.Results: PhA (r = -0.18, p = 0.01) and Xc/Height (r = -0.24, p < 0.001) were significantly associated with FRAIL scores. LMI and PhA were well correlated with each other (ρ = 0.76, p < 0.001), yet Xc/Height was the only bioimpedance index to significantly differ between frailty categories (F = 6.39, p = 0.002, ηp 2 = 0.06).Conclusions: Results suggest Xc/Height may be the only bioimpedance index indicative of frailty among older adults. Given the variety of assessments used to categorize frailty, these conclusions may be limited to the use of the FRAIL questionnaire; future research should compare LMI and PhA using multiple frailty indices.

Keywords: muscle quality, BIVA, phase angle, Aging, Fitness assessment

Received: 11 Nov 2024; Accepted: 28 May 2025.

Copyright: © 2025 Lafontant, Fukuda, Zamarripa, Tice, Suarez, Banarjee, Kim, Stout, Park, Xie and Thiamwong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Kworweinski Lafontant, Institute of Exercise Physiology and Rehabilitation Science, College of Health Professions and Sciences, University of Central Florida, Orlando, 32816, Florida, United States

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