Abstract 499: Lipoprotein(A) and Carotid Intimal Medial Thickness

Abstract

Introduction: Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of death and disability in both Japan and the United States. Carotid intimal medial thickness (CIMT) has been used as a marker of ASCVD risk. We examined various specialized lipoprotein parameters to determine their utilities for predictor of CIMT progression. Methods: Using plasma samples obtained from fasting men and women (n=2245) living in the Fukuoka area of Japan, (median age 59 years), at baseline we measured direct high density lipoprotein cholesterol (HDL-C), HDL2-C, HDL3-C, low density lipoprotein cholesterol (LDL-C), small dense LDL-C (sdLDL-C), triglycerides (TG), LDL-triglycerides (LDL-TG), lipoprotein(a) or Lp(a), and adiponectin. All assays were measured on an automated high throughput platform (Olympus AU400) using assay kits from the Denka Seiken Corporation (Niigata, Japan) and had within and between run coefficients of variations of < 5%. Blood pressure, body mass index, use of medications, and history of hypertension, dyslipidemia and diabetes were also assessed. CIMT of the common carotid artery was assessed bilaterally at baseline and after 5 years of follow up used trained technicians with analysis coefficients of variation of < 10%. Participants using statin therapy at baseline and during follow up were excluded. Results: After controlling for age and gender, only Lp(a) was significantly associated with change in CIMT over a 5 year period in this population. The data indicated that for every 1 log unit higher Lp(a) level at baseline, there was a 0.06 mm increase in CIMT over 5 years (p=0.02). While relationships were seen with other parameters and CIMT change, none of these other relationships reached statistical significance at p<0.05. We also observed significant relationships (p<0.05) between CIMT progression and age, gender, current smoking, history of hypertension, treatment of hypertension. Conclusions: Our data indicate that lipoprotein (a) as measured by immunoassay in an important predictor of the progression of atherosclerosis in the common carotid arteries of middle aged and elderly Japanese men and women, and serves as a valuable marker of ASCVD risk.