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.

Association between Human Paraoxonase 1 Activity and Intima-Media Thickness in Subjects under 55 Years of Age with Carotid Artery Disease

“…Although it seems clear that PON1 activity status is a better predictor of coronary heart disease risk than any of the known PON1 genotypes [32], only a few studies investigated the effect of PON1 activity on IMT [20, 31, 33, 34]. Most of them failed to show a significant decrease in PON1 activity in CAAD [31, 33, 34]. However, we found a significant negative correlation between PON1 activity and IMT, as well as salt-stimulated PON1 activity and IMT in the whole study population.…”

Lp-PLA2- a novel risk factor for high-risk coronary and carotid artery disease

“…Several studies have shown that the relationship between Lp-PLA 2 and carotid intima-media thickness (IMT), a marker of atherosclerotic disease, is not independent of other cardiovascular risk factors [26,39,50,51], whilst in the Mamlo Diet and Cancer Study, there was a weak association. Lp-PLA 2 activity and mass were associated with increased carotid IMT in an age-adjusted model but the model did not adjust for other traditional cardiovascular risk factors.…”

Relationship of Lipoproteine-Associated Phospholipase A2 With Coronary and Carotid Atherosclerosis in Kirgiz Ethnic Group

“…В частности, Kiortsis DH, et al [8] не выявили различий в активности ЛП-ФЛА2 в подгруппах с ТКИМ <0,7 мм и >0,7 мм среди пациентов с гиперлипидемией. Campo S, et al [7] не получили достоверных различий в уровне ЛП-ФЛА2, а также частоте полиморфных вариантов гена ЛП-ФЛА2 у больных с/без атеросклероза сонных артерий.…”

“…Недавно были опубликованы результаты мета-анализа 32 проспективных клинических исследований, согласно результатам которых уровни ЛП-ФЛА2 значимо связаны с риском ССЗ по типу непрерывной линейно-логарифмической зависимости [6]. В то же время не всем авторам удается выявить ассо-циацию уровней ЛП-ФЛА2 с развитием атеросклероза каротидных артерий [7,8], что может свидетельствовать о наличии расовых различий в реализации данной связи.…”