Estimated Pulse Wave Velocity (ePWV) as a Predictor of Functional Dependence in Middle-Aged and Elderly Populations: A Cross-Sectional and Longitudinal Analysis Using the CHARLS

Objective: This study aims to explore the predictive role of estimated pulse wave velocity (ePWV), a non-invasive measure of arterial stiffness, in assessing the risk of functional dependence. Methods: Data from the China Health and Retirement Longitudinal Study (CHARLS) were utilized to conduct cross-sectional and longitudinal analyses on 6,114 baseline participants and 2,592 longitudinal study participants. Functional dependence was evaluated using the Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) scales. ePWV was calculated based on age and blood pressure. Multinomial logistic regression and COX regression analyses were used for risk factor analysis. Group-restricted cubic spline plots were used to analyze the correlation between ePWV and the risk of functional dependence in subgroups. Results: A total of 6,114 participants were included in the baseline study, including 2,484 males (40.6%) and 3,630 females (59.4%), with an average age of 60 (54, 68) years. Among the 6,114 participants, 2,312 (37.8%) had functional dependence, with 1,475 (24.1%) having mild dependence and 837 (13.7%) having severe dependence. The severe dependence group had a higher age, more female participants, lower education levels, more hypertension, diabetes, and chronic diseases, and lower hemoglobin levels. Baseline ePWV was divided into four groups by quartiles. The study found that in the Q1-Q4 groups, as ePWV levels increased, the dependence score also gradually increased, and there were statistically significant differences among the groups (P < 2e-16). Logistic regression analysis showed that after adjusting for confounding factors, the risk of severe dependence in the Q4 group was 3.182 times that of the Q1 group (OR = 3.182, 95% CI: 2.446-4.142, P < 0.001), and the risk of mild dependence in the Q4 group was 1.732 times that of the Q1 group (OR = 1.732, 95% CI: 1.415-2.120, P < 0.001). The longitudinal study results showed that the risk of functional dependence in the persistent high-level ePWV group (class 4) was 2.55 times that of the persistent low-level ePWV group (class 1) (HR = 2.55, 95% CI: 2.14-3.04, P < 0.001). In subgroup analyses, ePWV was still significantly and linearly correlated with the occurrence of functional dependence. Conclusion: Estimation of pulse wave velocity (ePWV) is a reliable predictor of functional dependence, providing a simple and non-invasive tool for early risk assessment. This study highlights the importance of vascular health in functional decline and supports the use of ePWV in community health management and clinical screening.