Abstract
BACKGROUND: Cognitive decline in older adults with Cardiovascular Disease (CVD) is frequently mediated by chronic inflammation, oxidative stress, and cellular dysfunction. However, reliable biomarkers for early detection are still lacking. Phase angle (PhA), a sensitive bioelectrical impedance analysis (BIA) parameter reflecting cellular health and nutritional status, may serve as a novel tool for detecting cognitive impairment in this population. METHODS: In this cross-sectional study, 340 CVD patients (mean age: 80.8 ± 8.0 years; 36.5% male) were recruited from the Zhejiang Elderly Health Monitoring Cohort. PhA was measured using the InBody S10. Participants were stratified into cognitive impairment (n = 138) and cognitively normal (n = 202) groups based on Mini-Mental State Examination (MMSE) scores adjusted for education level. Group differences were analyzed via independent t-tests, Mann-Whitney U-tests, and chi-square tests. Binary logistic regression evaluated the association between PhA and cognitive ability. RESULTS: The cognitive impairment group exhibited significantly lower PhA (P < 0.001), older age, reduced grip strength, smaller calf circumference, slower gait speed (all P < 0.001), along with lower education levels and poorer physical activity intensity (both P<0.01). Additionally, they demonstrated worse performance in activities of daily living, nutritional status, balance, and swallowing function, along with greater frailty severity (all P < 0.001). Multivariate analysis confirmed PhA as an independent predictor of cognitive ability after adjusting for age, education, physical activity, grip strength, gait speed, and calf circumference (β = -0.474, OR = 0.62, 95% CI: 0.43-0.89, P = 0.01). ROC curve analysis revealed an optimal PhA threshold of 4.75° for cognitive impairment detection (specificity: 70.3%). CONCLUSION: Reduced PhA is independently associated with cognitive impairment risk in older CVD patients. Its noninvasive, cost-effective measurement supports its potential as a community screening tool and may provide a critical target for early intervention.