Lipoprotein(a) Levels Are Associated with the Size of Extracranial Arteries in Multiple Sclerosis

Background: Hyperlipidemia is associated with worse clinical and radiological outcomes in persons with multiple sclerosis (PwMS) and studies show greater MS extracranial arterial vessel pathology. Objective: The aim of this study was to determine the effect of lipid profile measures on extracranial arterial vessels in PwMS and healthy controls (HCs). Methods: Non-contrast magnetic resonance angiography was conducted on 104 PwMS and 41 HCs. The cross-sectional area (CSA) of the common carotid artery (CCA) and vertebral artery (VA) was measured using a semi-automated edge-detection/contouring method at cervical levels C4-C7. The lipid profile was obtained at the time of the scan. Repeated measures analyses adjusted for age, gender, and body mass index were used. Results: In PwMS, age was associated with CCA CSA (F = 7.65, η² = 0.083, p = 0.007) and lipoprotein(a) [Lp(a)] with VA CSA (F = 13.4, η² = 0.13, p < 0.001). These associations were not present in HCs. PwMS with Lp(a) ≥30 and ≥50 mg/dL, and within the highest Lp(a) quartile had significantly larger CCA and VA when compared to those with lower Lp(a) threshold values. Total cholesterol and low-and high-density lipoprotein cholesterol were not associated with CCA or VA CSA. Conclusions: Lp(a) levels are associated with CSA of major extracranial arterial vessels in PwMS but not in HCs. The clinical and pathological significance of these associations, if any, remains unknown.