Relationship of PCSK9 levels with indices of vascular function and subclinical atherosclerosis in patients with familial dyslipidemias

Abstract Objective Proprotein convertase subtilisin/kexin type 9 (PCSK9) levels predict cardiovascular risk. We aimed to determine the correlation of PCSK9 levels with predictors of cardiovascular risk, such as central hemodynamics and carotid intima-media thickness (cIMT), in subjects with familial dyslipidemias. Methods Thirty-three asymptomatic subjects (age: 45.4 ± 12.3 years, 21 men) with either familial combined hyperlipidemia or heterozygous familial hypercholesterolemia, free from hypolipidemic therapy, underwent evaluation for central hemodynamics (aortic augmentation index [AIx@75] and augmented pressure [AP]) and cIMT. PCSK9 levels were measured by ELISA. Results In the univariate model, circulating PCSK9 levels were related to age (r = 0.351, P = 0.045), AP (r = 0.442, P = 0.011), AIx@75 (r = 0.463, P = 0.007), and cIMT (r = 0.559, P = 0.011). In multivariate analysis, significant positive associations of AP, AIx@75, and cIMT with PCSK9 levels were observed after adjusting for relevant confounders (P = 0.018, P = 0.002, and P = 0.011, respectively). Patients with both high cIMT (>0.81 mm) and high AIx@75 (>20%) had significantly increased PCSK9 levels compared with subjects with both low cIMT and low AIx@75 (316 ng/ml vs. 155 ng/ml, P = 0.037). Conclusions In familial dyslipidemias, PCSK9 levels are positively associated with predictors of cardiovascular risk, such as central hemodynamics and cIMT. These relationships may aid in the stratification of cardiovascular risk by identifying a high-risk subgroup within these entities.