Limitations to implementation of measuring vascular ageing in routine clinical practice

Figure 1. Association between lipoprotein(a) and carotid–femoral pulse-wave velocity. Scatter plot of Lp(a) concentration and cfPWV. The red line shows the fitted trend, and the orange dashed horizontal line marks the threshold for high arterial stiffness, defined as cfPWV ≥ 10 m/s. Spearman ρ = 0.410; p < 0.001. cfPWV, carotid–femoral pulse-wave velocity; Lp(a), lipoprotein(a).

Figure 2. Spearman correlation heatmap. Pairwise Spearman correlations among continuous clinical, biochemical, haemodynamic, lipid, inflammatory, and renal variables. Red indicates positive correlations and blue inverse correlations. cfPWV, carotid–femoral pulse-wave velocity; Lp(a), lipoprotein(a); Hcy, homocysteine; SBP, systolic blood pressure; LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol; TG, triglycerides; hs-CRP, high-sensitivity C-reactive protein; eGFR, estimated glomerular filtration rate; ACR, albumin–creatinine ratio.

Figure 3. Panel (A) shows Lp(a), Panel (B) homocysteine, and Panel (C) the combined Lp(a)–homocysteine–PAD model. The grey dashed diagonal line indicates the line of no discrimination. AUCs were 0.641, 0.635, and 0.763, respectively. AUC, area under the curve; Hcy, homocysteine; Lp(a), lipoprotein(a); PAD, peripheral artery disease.

Figure 4. Predicted arterial stiffness across homocysteine and lipoprotein(a) concentrations. Contour plot of model-predicted cfPWV across homocysteine and Lp(a) concentrations. Warmer colours indicate higher predicted cfPWV, and contour lines indicate regions of similar predicted arterial stiffness. Dashed lines indicate the cohort-derived Youden-index thresholds for homocysteine (11.1 μmol/L) and Lp(a) (0.77 g/L). cfPWV, carotid–femoral pulse-wave velocity; Hcy, homocysteine; Lp(a), lipoprotein(a).

Figure 5. Adjusted carotid–femoral pulse-wave velocity according to joint biomarker status. Adjusted mean cfPWV across four Lp(a)–homocysteine groups. Error bars indicate 95% CIs, and the dashed line marks cfPWV ≥ 10 m/s. Models were adjusted for prespecified clinical covariates and PAD. CI, confidence interval; cfPWV, carotid–femoral pulse-wave velocity; Hcy, homocysteine; Lp(a), lipoprotein(a); PAD, peripheral artery disease.

Figure 6. Panel (A) shows the adjusted restricted cubic spline association between lipoprotein(a) [Lp(a)] concentration and predicted carotid–femoral pulse-wave velocity (cfPWV). Panel (B) shows the adjusted restricted cubic spline association between homocysteine concentration and predicted cfPWV. In both panels, the solid navy line represents the fitted cfPWV estimate, the shaded band represents the 95% confidence interval, and the red dashed horizontal line marks the threshold for high arterial stiffness, defined as cfPWV = 10 m/s. Models were adjusted for prespecified clinical covariates, including peripheral artery disease. cfPWV, carotid–femoral pulse-wave velocity; Lp(a), lipoprotein(a).