Association of LDL protein cargo with segmental pulse wave velocity in older adults in the atherosclerosis risk in communities study.

Background: Low-density lipoprotein cholesterol (LDL-C) is associated with brachial-ankle pulse wave velocity (baPWV). However, its relationship with femoral-ankle PWV (faPWV) or carotid-femoral PWV (cfPWV) is less consistent. In addition to its lipid cargo, LDL also has protein cargo. This study aims to examine and compare cross-sectional associations between LDL protein cargo or LDL-C and segment-specific PWV measures in an aging population. Methods: The study included 65 participants without dementia from the Atherosclerosis Risk in Communities (ARIC) study, with LDL separated from their plasma. LDL cargo proteins were quantified using a proteomic method based on mass spectrometry. Linear regression was utilized to evaluate the cross-sectional associations between LDL cargo protein or LDL-C and baPWV, faPWV, or cfPWV, after adjusting for covariates. Results: The 65 participants had a mean age of 76.3 years (SD = 5.4), 53.8% (35/65) were female, 30.8% (20/65) were Black. In the fully adjusted models, each SD increment of apolipoprotein B (apoB) in LDL and LDL-C was positively associated with an increase in baPWV of 103.0 cm/s (95% CI [43.3, 162.6]; p = 0.001) and 54.3 cm/s (95% CI [-5.9, 114.6]; p = 0.08), respectively. Each SD increment of complement component 3 (C3) in LDL was positively associated with an increase in cfPWV of 80.9 cm/s (95% CI [14.0, 147.7]; p = 0.02), but each SD increment of LDL-C was negatively associated with a decrease in cfPWV of 62.4 cm/s (95% CI [-123.1, -1.8]; p = 0.04). Conclusion: We identified differential associations of LDL cargo protein apoB and C3 as well as LDL-C with baPWV or cfPWV.