Oxidative status and paraoxonase activity in children with asthma.

OBJECTIVE To compare paraoxonase activity and changes in oxidative status in asthmatic children and healthy children by determining serum paraoxonase activity and total oxidative status, total antioxidant capacity and lipid hydroperoxidation. METHODS Forty two asthmatic children were compared with 32 healthy children of similar age and sex. To evaluate the paraoxonase and oxidative status, total antioxidant capacity and lipid hydroperoxidation were examined. Serum paraoxonase activity was evaluated by measuring the rate of paraoxon hydrolosis. Oxidative status was evaluated by the method developed by Erel. Lipid hydroperoxide was measured by an iodometric method. RESULTS In comparison with the healthy control group, the paraoxonase activity of the asthmatic children was found to be low (163.7 +/- 73.0 (U/L) and 349.2 +/- 153.9 (U/L), P = 0.002) and total oxidant status (9.0 +/- 3.5 micromol H2O2 Eq/L and 13.4 +/- 7.0 micromol H2O2 Eq/L, P =0.002), total antioxidant capacity (5.5 +/- 2.5 micromol Trolox Eq/L and 1.0 +/- 0.6 micromol Trolox Eq/L, P < 0.001), and lipid hydroperoxidation values (9.9 +/- 3.4 micromol H2O2 Eq/L and 4.4 +/- 1.5 micromol H2O2 Eq/L, P < 0.001) were found to be high. The high density lipoprotein (HDL) concentration of the asthmatic children was lower than that in the control group (40.1 +/- 9.2 mg/dl and 54.5 +/- 15.9 mg/dl, P < 0.001) CONCLUSION In asthmatic children, when total oxidant status, total antioxidant capacity and lipid hydroperoxidation levels increase, paraoxonase activity decreased.