Pulse Pressure Dynamics and Cardiovascular-Kidney-Metabolic Syndrome Progression, Incident Hypertension, and Mortality: A Longitudinal Study from the CHARLS Cohort

Background The cardiovascular-kidney-metabolic (CKM) staging system unifies metabolic, renal, and cardiovascular pathological conditions. Pulse pressure (PP), a simple marker of arterial stiffness reflecting vascular aging, may predict CKM progression. However, it remains unknown whether PP predicts CKM advancement across disease stages, and its longitudinal links with hypertension and mortality are poorly defined. This study evaluated associations of PP with CKM progression, to predict new-onset hypertension and long-term all-cause mortality among middle-aged and elderly Chinese individuals. Methods We used data from the China Health and Retirement Longitudinal Study (CHARLS, baseline 2011, follow-up to 2020). PP was calculated as systolic minus diastolic blood pressure. Logistic regression assessed baseline PP and 4-year CKM progression, and 4-year PP change (ΔPP) and new-onset hypertension. Cox models examined baseline PP and all-cause mortality with sequential confounder adjustment. Restricted cubic splines (RCS) modelled nonlinear relationships. Results The final sample included 12,853 participants (mean age 58.5 years, 48.5% male), with 1,712 deaths over a median 9-year follow-up. Fully adjusted analyses showed baseline PP predicted CKM progression solely in CKM stage 3 (subclinical cardiovascular disease, CVD; OR = 1.28, 95%CI 1.03–1.59, P = 0.028), with no significance for stages 0–2. Each 10 mmHg rise in ΔPP conferred a 4.90-fold higher risk of incident hypertension (OR = 4.90, 95%CI 4.09–5.94, P < 0.001). Baseline PP linearly predicted mortality (HR = 1.01 per 10 mmHg, 95%CI 1.005–1.014, P < 0.001). RCS revealed a U-shaped PP–mortality curve with the risk nadir at 44 mmHg. Conclusions PP exerts stage-specific predictive effects on CKM progression, limited to the subclinical CVD stage. Rising ΔPP strongly predicts incident hypertension, while baseline PP displays a U-shaped mortality association, indicating an optimal PP range for survival. PP serves as a low-cost, non-invasive vascular aging biomarker to support stratified CKM risk assessment among aging Chinese adults.