Objective: To analyze whether nasal continuous positive airway pressure (CPAP) reduces oxidative stress in patients with sleep apnea-hypopnea syndrome (SAHS).
Patients and methods: Thirty-six patients with SAHS requiring nasal CPAP treatment and 10 controls in whom SAHS was ruled out were enrolled. Oxidative stress was evaluated by measuring plasma malondialdehyde (MDA) concentrations to assess lipid peroxidation at the beginning of the study and then again after a mean (SD) of 2.9 (0.6) months of nasal CPAP. Plasma MDA concentrations were determined by measuring thiobarbituric acid reactive substances. We controlled for the following factors known to influence oxidative stress: age, sex, use of vitamin supplements, smoking habit, body mass index (kg/m2), ischemic cardiopathy, hypertension, diabetes, and hypercholesterolemia.
Results: The mean age of patients with SAHS was 51.4 (9.9) years and the mean body mass index was 32.9 (5.3) kg/m2. Nasal CPAP was titrated to a mean pressure of 8.9 (3.4) cm H2O. The mean score on the Epworth sleepiness scale was 10.2 (4.3) before treatment and 4.2 (2.8) after treatment (P<.001). The apnea-hypopnea index decreased from 43.7 (22.6) before treatment to 4 (3.5) after treatment (P<.001). Mean MDA concentrations in patients with SAHS were 2.0 (1.1) micromol/mL before treatment and decreased significantly to 1.6 (.07) micromol/mL after treatment, whereas MDA concentrations remained unchanged in control subjects.
Conclusions: Nasal CPAP treatment significantly reduced oxidative stress in patients with SAHS in our study.