Neurocognitive impairment is correlated with oxidative stress in patients with moderate-to-severe obstructive sleep apnea hypopnea syndrome

Background and objectives: Patients with obstructive sleep apnea hypopnea syndrome (OSAHS) are associated with increased risk of neurocognitive impairment, which are largely recognized as mild cognitive impairment (MCI), and oxidative stress is postulated as one of the underlying mechanisms. This study aimed to investigate the relationship between MCI and oxidative stress biomarkers in OSAHS. Methods: A total of 119 middle-aged patients with moderate-to-severe OSAHS were included. Based on the baseline Montreal Cognitive Assessment (MoCA, validated Chinese version), 86 and 33 patients presented with normal cognitive function (NC, MoCA >= 26) and mild cognitive impairment (MCI, MoCA < 26), respectively. Overnight PSG, MoCA and serum levels of ischemia-modified albumin (IMA), malondialdehyde (MDA) and advanced oxidation protein products (AOPP) were collected and analyzed. Results: Compared to NC group, patients with MCI were characterized with significantly greater waist-to-height ratio, AHI, ODI and time ratio of SpO(2)<90%, and lower average SpO(2) and time ratio of rapid eye movement (REM). All three oxidative stress biomarkers were markedly elevated in MCI group. Binary logistic regression analysis demonstrated that MCI is significantly correlated with serum levels of IMA, REM ratio and the age of patients. Conclusions: The neurocognitive impairment in moderate-to-severe OSAHS patients is associated with significantly elevated oxidative stress. IMA might be a new useful biomarker correlated with mild cognitive impairment of the patients. (C) 2016 Published by Elsevier Ltd.