Phase Angle as a Predictor for Physical Function in Institutionalized Independent Older Adults

Area of Science:

• Gerontology and Geriatric Medicine
• Biophysics and Bioimpedance Analysis
• Physical Therapy and Rehabilitation

Background:

• Cellular health, often reflected by phase angle (PhA), is crucial for maintaining physical function in aging populations.
• Previous research suggests a correlation between PhA and body composition, but its predictive role in physical function requires further investigation, especially in institutionalized older adults.

Purpose of the Study:

• To investigate the relationship between phase angle (PhA) and physical function in institutionalized, independent older adults.
• To determine if PhA can serve as a predictor of physical function in this demographic.

Main Methods:

• Phase angle (PhA) was measured using 50 kHz electrical bioimpedance in 100 institutionalized, independent older adults.
• Physical function was assessed using the Senior Fitness Test Battery, including tests like the 8 ft up-and-go, 6-minute walk, 30-second chair stand, and arm curl.
• Multivariate regression analyses were performed to evaluate the predictive power of physical function tests on PhA.

Main Results:

• Phase angle (PhA) showed significant correlations with most physical fitness tests, excluding arm curls.
• Multivariate analysis revealed that physical function tests significantly predicted PhA across three models (R-squared ranging from 12.5% to 13.1%, p < 0.005).
• Predictive influence was particularly strong in men, with R-squared values reaching up to 31.6% (p < 0.016), and significant for women in one model (p = 0.030, 9.3%).

Conclusions:

• The study confirms a significant relationship between phase angle (PhA) and physical function in institutionalized older adults.
• Phase angle (PhA) emerges as a potentially valuable and reliable predictor of physical function in this population.
• These findings support the use of PhA as a non-invasive biomarker for assessing functional status and guiding interventions in geriatric care.