Paraoxonase and arylesterase activities in coronary artery disease

Paraoxonase-1 is an enzyme with three activities which are inversely related to cardiovascular diseases. Accordingly, the aim of the study was to investigate the paraoxonase, arylesterase activities and oxidative/anti-oxidative status in coronary artery disease (CAD) and their correlation with the extent of CAD.

Study populations of 193 patients with angiographically documented CAD, 83 patients with normal coronary angiograms (NCAD) and 55 healthy volunteers were included in the study. The patients with CAD were divided into three categories according to the number of diseased coronaries. Also, a Gensini score was calculated for each patient. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. Oxidative and anti-oxidative status was evaluated by measuring serum lipid hydroperoxide (LOOH), total anti-oxidant status (TAS) and free sulfhydryl groups (-SH = total thiol). Lipid parameters were determined by routine laboratory methods.

Serum paraoxonase and arylesterase activities, TAS and -SH levels were lower in the CAD group compared with the NCAD group and control group (P < 0.05, all). Serum LOOH levels of the CAD group were greater than those in both the control and NCAD groups (P < 0.05). The major decreases in paraoxonase, arylesterase activities, -SH and TAS levels and the major increase in LOOH levels were observed in the 3-vessels disease group. In multiple linear regression analysis, the Gensini score was independently correlated with paraoxonase activity (beta = -0.469, P < 0.001), -SH levels (beta = -0.232, P < 0.001), HDL levels and history of diabetes.

Both paraoxonase activity and -SH levels are independently associated with the presence and extent of CAD. Reduced paraoxonase activity and -SH levels may play a role in the severity of coronary atherosclerosis.