Urinary Proteomic Profile of Arterial Stiffness as a Predictor of Mortality and Cardiovascular Outcomes

Abstract

Background: The underlying mechanisms of arterial stiffness has not been fully understood. This study aimed to illuminate its pathophysiology by using urinary proteomics and to determine the prognostic value of the urinary proteomic markers for adverse outcomes. Methods: Aortic stiffness was measured with carotid-femoral pulse wave velocity (PWV) in 669 randomly recruited Flemish (mean age, 50.5 years; 51.1% women). Urinary proteome was analyzed using capillary electrophoresis coupled with mass spectrometry. PWV-derived urinary proteomic score (PWV-UP) was developed by modelling PWV with proteomics data at baseline through orthogonal projections to latent structures. Adverse outcomes included all-cause mortality and fatal and non-fatal cardiovascular (CV) events. Linear regression and Cox proportional hazard regression were used. Pathway analysis was performed with the Reactome Pathway Database. Findings: PWV-UP that consisted of 2,336 peptides explained 65% variance of PWV, which was higher than 36% explained by clinical risk factors. After adjusting for potential confounders, PWV-UP was significantly associated with PWV (β=0.73 [95% confidence interval: 0.67–0.79], P<0.0001). Over a period of 9.2 years (median), 36 participants died and 75 experienced fatal and non-fatal CV events. The incidence of mortality and CV events was higher at the upper half of PWV-UP (P≤0.0002). The adjusted hazard ratios (+1 standard derivation) were 1.46 (1.08–1.97) for all-cause mortality, 2.04 (1.07–3.87) for CV mortality and 1.39 (1.11–1.74) for CV events (P≤0.031). For PWV, the corresponding estimates were 1.25 (0.97–1.60), 1.35 (0.85–2.15), and 1.22 (1.02–1.47), respectively (P≥0.033). The proteins in PWV-UP involved in multiple pathways, such as collagen turnover, cell adhesion, inflammation, and lipid metabolism. Interpretation: PWV-UP was independently associated with arterial stiffness and explained the variance of PWV better than clinical determinants. PWV-UP, but not PWV, independently predicted all-cause mortality and CV mortality, implying that PWV-UP-associated proteins may be multifaceted and involved in diverse pathological processes beyond arterial stiffness. Funding Information: European Union (HEALTH-F7-305507 HOMAGE), the European Research Council (Advanced Researcher Grant 2011-294713-EPLORE and Proof-of-Concept Grant 713601-uPROPHET), the European Research Area Net for Cardiovascular Diseases (JTC2017-046-PROACT), and KU Leuven (STG-18-00379) currently support the Studies Coordinating Centre in Leuven. Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: The study was approved by the University of Leuven Ethics Committee. All participants provided written informed consent.