Avaliação do estresse oxidativo na síndrome da apneia obstrutiva do sono e utilização de terapia oxidante

Abstract

Obstructive sleep apnea syndrome (OSAS) is a chronic disease caused by an intermittent or partial obstruction of the upper airways during sleep. The cycles of hypoxia and reoxygenation generate changes in the oxidative balance with an increase in the formation of reactive oxygen species that react easily with other molecules, changing their functions. This research was developed to assess oxidative stress in patients with OSAS at its different levels of severity (mild, moderate, severe) by measuring malondialdehyde (MAD) and the antioxidant effects with de vitamin C. Patients underwent a polysomnography exam to diagnose OSAS and its severity. According to the AHI (apnea and hypopnea index), the participants were divided into groups: control G0 (AHI <5 / h); mild G1 (AHI 5 / h ≥ and <15 / h); moderate G2 (AHI ≥ 15 and ≤ 30 / h); and severe G3 (AHI> 30 / h). Age, weight, BMI (body mass index), cervical circumference, in addition to blood pressure measurement, and 2 venous punctures were used to measure MAD before and after antioxidant therapy with vitamin C 1 g / day for 30 consecutive days. There was no statistical difference between the groups regarding age. About weight, BMI and cervical circumference, these were higher in the groups of experimental cases when compared to control, being even proportional to the severity of OSAS. Blood pressure levels were also significantly elevated in patients. As for MAD dosages before and after antioxidant therapy, there were no changes between groups. It was concluded that oxidative stress in OSAS cannot be measured by the blood dosage of MAD, and that vitamin C is not able to reduce it, when assessed through the levels of this marker.