| Keywords |
Physical activity; Phase angle; Older people; Bioelectrical impedance analysis |
| Abstract |
The purpose of this study was to investigate the associations of total physical activity (TPA) and moderate-to-vigorous physical activity (MVPA) with phase angle (PhA) by sex among Korean older adults. This cross-sectional study analyzed data from 1,530 Korean older adults aged ≥ 65 years (650 men and 880 women) who participated in the 2024 Korea National Health and Nutrition Examination Survey (KNHANES). Physical activity was assessed using the physical activity questionnaire included in the KNHANES and expressed as metabolic equivalent task (MET)-min/week. TPA was categorized into sex-specific quartiles, and MVPA was classified based on the WHO physical activity guidelines. PhA was measured using bioelectrical impedance analysis. Complex sample general linear models and linear regression analyses were performed after adjustment for potential confounders. In women, adjusted mean PhA significantly increased across TPA quartiles, from 4.47° in Q1 to 4.63° in Q4 (p for trend < .001). In contrast, no significant linear trend was observed in men (p for trend = .124). In complex sample linear regression analyses, women in the third and fourth quartiles of TPA showed significantly higher PhA compared with those in the lowest quartile, even after additional adjustment for resistance exercise (Q3: β = 0.114, 95% CI = 0.010?0.218; Q4: β = 0.159, 95% CI = 0.066?0.253). In men, significant associations observed in the initial model were attenuated after adjustment for resistance exercise. MVPA was not independently associated with PhA in either sex, and no significant linear trends were identified across MVPA categories. These findings suggest that overall physical activity volume, including habitual daily movement, may be more closely associated with cellular health than engagement in MVPA alone in older adults. Additionally, resistance exercise may partly explain the association between TPA and PhA in older men. |