Validation of Phase Angle Cutoff Values Derived From Bioelectrical Impedance Analysis for Sarcopenia Screening in Community-Dwelling Older Korean Adults

Abstract

Objectives: Sarcopenia, characterized by progressive loss of skeletal muscle mass and function, poses a significant risk to the aging population. This study aimed to validate the efficacy of phase angle (PhA) derived from bioelectrical impedance analysis (BIA) as a screening tool for sarcopenia in community-dwelling middle-aged and older Korean adults.

Design: The study employed a cross-sectional design to assess the association between PhA and sarcopenia.

Setting and participants: The study was conducted in Busan, South Korea, and included 699 community-dwelling participants aged 50 years and older using a purposive sampling method.

Methods: Sarcopenia was classified based on the Asian Working Group for Sarcopenia 2019 criteria. Participants completed the SARC-F questionnaire, a self-assessment tool for sarcopenia risk. BIA was used to measure PhA, a parameter reflecting body composition. Statistical analyses, including analysis of variance, χ² tests, and receiver operating characteristic curve analysis, were used to compare PhA values between groups and determine optimal cutoff points.

Results: Among 699 participants (78.5% female, mean age 75.7 years), 97 had sarcopenia and 77 had severe sarcopenia. Mean PhA values were lower in those with sarcopenia (men: 5.1, women: 4.6) and severe sarcopenia (men: 4.8, women: 4.3) compared with those without (men: 6.0, women: 5.2). PhA demonstrated superior screening capability for sarcopenia compared with SARC-F scores in both men and women. Optimal PhA cutoff values for detecting severe sarcopenia were 5.35 for men [area under the curve (AUC): 0.767] and 4.75 for women (AUC: 0.816), indicating strong potential for clinical application.

Conclusions and implications: The established PhA cutoff values can be integrated into routine health assessments, enabling early detection and targeted interventions that could improve the quality of life of this population.

Keywords: Early detection; community screening; older adults; phase angle; sarcopenia screening.