The levels of advanced oxidation protein products in patients with obstructive sleep apnea syndrome.

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is characterized by repeated episodes of complete or partial obstructions of the upper airway during sleep, frequently followed by transient hypoxemia. Advanced oxidation protein products (AOPP) are a family of oxidized protein products, and oxidative stress has a substantial role in the morbidity of OSAS.

AIMS

The aim of this study was to investigate the serum levels of advanced oxidation protein products (AOPP) as a marker of oxidative stress, and their correlation with polysomnographic parameters in patients with obstructive sleep apnea syndrome (OSAS). Additionally, we investigated the effect of positive airway pressure (PAP) treatment on serum AOPP values and compared the levels before and after the treatment.

METHODS

The study enrolled a total of 125 subjects including 59 patients with severe OSAS, 34 patients with moderate OSAS, 32 patients with mild OSAS, and 40 healthy controls. Mean AOPP values were compared between OSAS groups and control groups. Correlations between AOPP and polysomnographic parameters were investigated. Mean AOPP values before and after 6-month PAP therapy were compared.

RESULTS

Significantly elevated AOPP levels were found in severe and moderate OSAS groups in comparison with mild OSAS and control groups. AOPP was directly correlated with apnea-hypopnea index, percentage of total time spent with oxygen saturation below 90%, oxygen desaturation index, maximum obstructive apnea duration, arousal index, and number of obstructive apneas accompanying bradycardia but inversely correlated with average SPO (%), minimum SPO, and percentage of non-REM stage 3 sleep. There was no statistically significant difference between AOPP values before and after PAP therapy.

CONCLUSIONS

AOPP, which is an oxidative stress marker, was found to be high in OSAS patients. Especially, high levels in moderate and severe OSAS patients may be an indicator of increased morbidity. After 6 months of PAP treatment, there was no statistically significant change in these levels.