Serum paraoxonase activity and oxidative stress in patients with adult nephrotic syndrome

Objective: It has been shown that low paraoxonase-1 (PON1) activity is associated with a risk of an early development of atherosclerosis. In the present study, we investigated serum paraoxonase, and arylesterase activities and oxidative stress in patients with adult nephrotic syndrome (NS). In addition, we examined the relationship between these measurements and atherosclerosis. Methods: Twenty-one patients with NS and 21 healthy controls were enrolled in the study. Serum basal and salt-stimulated paraoxonase activities, arylesterase activity, lipid hydroperoxide (LOOH) and total thiol (SH) levels were measured. Results: Serum basal and salt-stimulated paraoxonase activities, arylesterase activity and total SH levels were significantly lower in patients with NS than in controls (p < 0.05, p < 0.05, p < 0.01 and p < 0.05, respectively), whereas LOOH levels were significantly higher (p < 0.05). Serum LOOH levels were significantly correlated with total-SH levels in patients with NS (r = -0.467; p < 0.01). Moreover, proteinuria levels were significantly correlated with serum LOOH levels (r = 0.397; p < 0.01), whereas no correlation was found among serum paraoxonase activity, arylesterase activity and total-SH levels in NS patients (p > 0.05). Conclusions: We concluded that oxidative stress is increased, while serum PON1 activity is decreased in patients with adult NS. In addition, these results indicate that lower PON1 activity is associated with an oxidant-antioxidant imbalance that may contribute to atherosclerosis in adult patients with NS. (C) 2011 Elsevier Ireland Ltd. All rights reserved.