title: Lack of association between carotid intima-media thickness and PAF-acetylhydrolase mass and activity in patients with primary hyperlipidemia.
abstract: Carotid intima media thickness (IMT), represents an important clinical indicator of early atherosclerosis. Human plasma platelet-activating factor acetylhydrolase (PAF-AH) is an enzyme primarily associated with low-density lipoprotein (LDL) while a small proportion of enzymatic activity is also associated with high-density lipoprotein (HDL). Plasma paraoxonase 1 (PON1) is an esterase exclusively associated with HDL. The authors investigated the possible relationship between carotid IMT and the plasma levels of PAF-AH mass and activity as well as the PON1 activity in hyperlipidemic patients. One hundred unrelated patients with primary hyperlipidemia and 67 age-and sex-matched normolipidemic apparently healthy volunteers participated in the study. The PAF-AH activity in total plasma and in HDL-rich plasma (HDL-PAF-AH activity), the plasma PAF-AH mass, and the serum PON1 activities toward paraoxon and phenyl acetate were determined. The plasma PAF-AH mass and activity were higher in hyperlipidemic patients compared to controls, whereas the HDL-PAF-AH activity, as well as the serum PON1 activities were not significantly different between the studied groups. When hyperlipidemic patients were divided into 2 subgroups according to their IMT values (IMT <0.7 mm and IMT > or =0.7 mm) patients with IMT > or =0.7 mm had significantly higher age, and serum triglyceride concentrations, whereas no difference was found in the plasma PAF-AH mass and activity as well as in the HDL-PAF-AH activity between the 2 studied subgroups. The same phenomenon was observed for serum PON1 activities. In a multivariate analysis, only the age was significantly correlated with IMT values (p<0.05). Neither the total plasma PAF-AH mass and activity nor the HDL-PAF-AH activity are associated with early carotid atherosclerosis.
authors.affiliation: Laboratory of Physiology, University of Ioannina, Ioannina, Greece.
authors.forename: Dimitrios N
authors.initials: DN
authors.lastname: Kiortsis
authors.forename: Sofia
authors.initials: S
authors.lastname: Tsouli
authors.forename: Evangelia S
authors.initials: ES
authors.lastname: Lourida
authors.forename: Vasilios
authors.initials: V
authors.lastname: Xydis
authors.forename: Maria I
authors.initials: MI
authors.lastname: Argyropoulou
authors.forename: Moses
authors.initials: M
authors.lastname: Elisaf
authors.forename: Alexandros D
authors.initials: AD
authors.lastname: Tselepis
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood*; D000328:Adult; D000368:Aged; D043303:Aryldialkylphosphatase / Q000097:blood; D002339:Carotid Arteries / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood* / Q000473:pathology*; D008297:Male; D008875:Middle Aged
chemical_list: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D043303:Aryldialkylphosphatase