Vascular ageing and cognitive function: blood pressure mediation in the association between arterial stiffness and...

Arterial stiffness has emerged as a potential risk factor for cognitive decline, yet underlying mechanisms remain incompletely understood. We investigated the longitudinal association between arterial stiffness and cognitive function in Chinese adults, examining blood pressure components as potential mediators.

Data from 3485 participants (aged 45-90) in the China Health and Retirement Longitudinal Study (2011-2018) were analysed. Arterial stiffness was assessed using estimated pulse wave velocity (ePWV). Multivariate regression models examined associations between baseline ePWV and cognitive outcomes. Mediation analyses quantified blood pressure mediation effects.

Baseline cognitive scores demonstrated significant inverse relationships across ePWV tertiles: 13.67 ± 2.62, 13.40 ± 2.68 and 12.93 ± 2.79 (P < 0.001), persisting at 7-year follow-up. Each unit increase in ePWV was associated with cognitive decline in fully adjusted models (β = -0.14, 95% CI: -0.23 to -0.05, P = 0.003). Whilst unadjusted analysis suggested blood pressure mediation (systolic: 63.4%, diastolic: 47.0%), these effects became non-significant after demographic adjustment. Restricted cubic spline analysis revealed optimal ePWV thresholds below 8.0 m/s, with U-shaped blood pressure interactions showing maximum cognitive vulnerability at intermediate ranges (systolic: 110-140 mmHg, diastolic: 70-90 mmHg).

ePWV independently predicts long-term cognitive decline in Chinese adults through mechanisms beyond blood pressure elevation alone. The U-shaped interactions between ePWV and blood pressure reveal maximum cognitive vulnerability at intermediate blood pressure ranges (110-140/70-90 mmHg), suggesting that cognitive risk assessment should integrate ePWV measures alongside blood pressure control, with optimal targets potentially individualised based on arterial compliance status.