[Changes in the processes of the lipid peroxidation and antioxidant defense system in patients with obstructive sleep apnoea syndrome].

The objective of this study was to evaluate the lipid peroxidation (LPO) and antioxidant defense (AoD) system in patients with varying hypoxia in obstructive sleep apnoea/hypnoea syndrome (OSA/HS). The study of the LPO-AOD system in patients with OSA/HS revealed the specific features of some metabolic reactions that could reflect the development of adaptive-compensatory processes. The patients with upper airway hyperresistance syndrome were found to have increases in general blood antioxidant activity (AOA) and dienic conjugate levels, which might be interpreted as an initial stress reaction or prompt (emergency) adaptation. Mild OSAS and hypoxia characterized by a reduction in general AOA and a higher concentration of primary lipid peroxidation products reflect the development of adaptive-compensatory processes and are defined as a transitional stage between prompt and long-term adaptation. With higher hypoxic action on the body, which is observed in the moderate OSA/HS group, it may be said that there is a long-term adaptation to chronic exposure of hypoxia. The lower indices of general AOA with a reduction in LPO products, which were observed in the severe OSA/HS group, demonstrate another functioning level, suggesting the depletion of functional reserves.