title: Correlation between serum levels of proprotein convertase subtilisin/kexin type 9 (PCSK9) and atherogenic lipoproteins in patients with coronary artery disease.
abstract: BACKGROUND
  Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key regulator of serum low-density lipoprotein (LDL) cholesterol levels. Recently, PCSK9 has additionally been related to metabolic risk factors such as the levels of triglycerides, apolipoprotein B (apoB), insulin, and glucose, as well as body mass index. The purpose of this study was to investigate correlations between serum levels of PCSK9 and apoB-containing atherogenic lipoproteins in patients with coronary artery disease (CAD).
  
  
  METHODS
  Serum levels of PCSK9 and lipoprotein(a) [Lp(a)]; small, dense LDL; and oxidized LDL were measured in 101 patients with CAD who were not receiving lipid-lowering therapy.
  
  
  RESULTS
  Serum hetero-dimer PCSK9 levels were positively correlated with serum levels of Lp(a) (r = 0.195, p = 0.05); small, dense LDL (r = 0.336, p = 0.0006); and oxidized LDL (r = 0.268, p = 0.008). Multivariate regression analyses showed that serum hetero-dimer PCSK9 was a significant predictor of serum levels of Lp(a) (β = 0.235, p = 0.01); small, dense LDL (β = 0.143, p = 0.03); and oxidized LDL (β = 0.268, p = 0.008).
  
  
  CONCLUSIONS
  Serum PCSK9 levels were positively correlated with serum levels of Lp(a); small, dense LDL; and oxidized LDL in patients with CAD. This suggests that the interaction between serum PCSK9 and apoB-containing lipoproteins plays a role in establishing the atherosclerotic status of patients.
  
  
  BACKGROUND
  UMIN Clinical Trials Registry, UMIN ID: C000000311 .
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Yokohama Sakae Kyosai Hospital, Federation of National Public Service Personnel Mutual Associations, 132 Katsura-cho, Sakae-ku, Yokohama, 247-8581, Japan. nozue2493@yahoo.co.jp.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nozue
authors.affiliation: Advanced Medical Technology and Development Division, BML Inc., Kawagoe, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hattori
authors.affiliation: Advanced Medical Technology and Development Division, BML Inc., Kawagoe, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Advanced Medical Technology and Development Division, BML Inc., Kawagoe, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kujiraoka
authors.affiliation: Advanced Medical Technology and Development Division, BML Inc., Kawagoe, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Department of Medicine, Division of Diabetes, Metabolism, and Endocrinology, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hirano
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Yokohama Sakae Kyosai Hospital, Federation of National Public Service Personnel Mutual Associations, 132 Katsura-cho, Sakae-ku, Yokohama, 247-8581, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Michishita
keywords: Lipoprotein(a); Low-density lipoprotein (LDL) cholesterol; Oxidized LDL; Proprotein convertase subtilisin/kexin type 9 (PCSK9); Small, dense LDL