Serum paraoxonase, arylesterase activities and oxidative status in patients with insomnia.

The aim of this study was to investigate serum paraoxonase (PON) activity, arylesterase (ARE) activity, total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) levels in patients with insomnia and to determine whether there was a relationship between oxidative stress and insomnia.A total of 29 insomniacs and 25 healthy controls were recruited in this study. Serum PON and ARE activities, TAS and TOS level were determined, and OSI were calculated.Patients with insomnia had lower PON and ARE activities as compared to healthy controls (PON: 82.0±30.0 U/L vs. 193.5±58.4 U/L, p < 0.001; ARE: 143.0±26.7 U/L vs. 175.0±27.1 U/L, p < 0.001; respectively). Serum TAS was lower, while TOS and OSI were higher in the insomnia group than in the control group (TAS: 1.13±0.29 mmol Trolox equivalent/L vs. 1.70±0.35 mmol Trolox equivalent /L, p < 0.001; TOS: 18.68±5.03 µmol H2O2 equivalent/L vs. 10.92±2.21 µmol H2O2 equivalent/L, p < 0.001; OSI: 1.76±0.74 vs. 0.68±0.23, p < 0.001; respectively).Patients with insomnia have increased systemic oxidative stress and reduced levels of serum antioxidant enzymes. Oxidative stress appears to be an underlying condition associated with insomnia.