title: Gender-specific correlation between plasma myeloperoxidase levels and serum high-density lipoprotein-associated paraoxonase-1 levels in patients with stable and unstable coronary artery disease.
abstract: OBJECTIVE
  Low high-density lipoprotein (HDL) cholesterol is well-established as a negative risk factor for coronary artery disease (CAD) and its anti-oxidant property has been attributed mainly to the HDL-bound enzyme paraoxonase-1 (PON-1). Recently, myeloperoxidase (MPO), a pro-oxidant enzyme released from activated neutrophils, has been shown to alter the atheroprotective function of HDL to a dysfunctional form. This study investigated the relationship between plasma MPO and serum PON-1 levels in patients with stable (SAP) and unstable angina pectoris (UAP).
  
  
  METHODS
  Plasma MPO levels and serum PON-1 concentration/activity were measured in patients with SAP (n = 226), UAP (n = 151) and in control subjects (n = 99).
  
  
  RESULTS
  Plasma MPO levels in UAP patients were significantly higher than those in SAP patients or in control subjects (UAP, 21.6[16.7-44.6]; SAP, 19.3[15.7-29.1]; control, 15.9[14.7-18.7] ng/mL; P < 0.0001). Serum PON-1 concentrations in UAP and SAP patients were significantly lower than those in control subjects (UAP, 55.6[45.9-69.7]; SAP, 55.0[46.9-64.9]; control, 62.5[51.1-78.8] μg/mL; P = 0.0002). Plasma MPO levels showed a weak inverse correlation with serum PON-1 concentrations in all subjects (R = -0.163, P < 0.0005). Moreover, in women, plasma MPO levels showed a significant inverse correlation with serum PON-1 concentrations and PON-arylesterase activity in SAP (concentration: R = -0.537, P < 0.0001; arylesterase-activity: R = -0.469, P < 0.001) and UAP (concentration: R = -0.340, P < 0.05; arylesterase-activity: R = -0.350, P < 0.05) patients, but not in men.
  
  
  CONCLUSIONS
  This study demonstrates that plasma MPO levels have a significant inverse correlation with PON-1 levels, especially in women, in SAP and UAP patients, and suggests that an imbalance between pro-oxidants and anti-oxidants may contribute to the progression of coronary plaque instability.
authors.affiliation: Department of Cardiology, Osaka City General Hospital, Osaka, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Yunoki
authors.forename: Takahiko
authors.initials: T
authors.lastname: Naruko
authors.forename: Mayumi
authors.initials: M
authors.lastname: Inaba
authors.forename: Takeshi
authors.initials: T
authors.lastname: Inoue
authors.forename: Masashi
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugioka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ohsawa
authors.forename: Yoko
authors.initials: Y
authors.lastname: Iwasa
authors.forename: Ryushi
authors.initials: R
authors.lastname: Komatsu
authors.forename: Akira
authors.initials: A
authors.lastname: Itoh
authors.forename: Kazuo
authors.initials: K
authors.lastname: Haze
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshiyama
authors.forename: Anton E
authors.initials: AE
authors.lastname: Becker
authors.forename: Makiko
authors.initials: M
authors.lastname: Ueda
mesh_terms: D000368:Aged; D060050:Angina, Stable / Q000097:blood*; D000789:Angina, Unstable / Q000097:blood*; D000975:Antioxidants / Q000378:metabolism; D043303:Aryldialkylphosphatase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood*; D048909:Diabetes Complications; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016877:Oxidants / Q000378:metabolism; D018384:Oxidative Stress; D009195:Peroxidase / Q000097:blood*; D011110:Polymorphism, Genetic; D012737:Sex Factors
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D008075:Lipoproteins, HDL; D016877:Oxidants; D009195:Peroxidase; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human
keywords: Angina; Myeloperoxidase; Oxidative stress; Paraoxonase