[Relationship between cognitive impairment and sleep-related respiratory indexes in patients with obstructive sleep...

Objectives: To investigate the cognitive impairment in patients with obstructive sleep apnea (OSA), and it's relationship with sleep-related respiratory indexes. Methods: A total of 126 patients who were diagnosed with OSA and received treatment in the Sichuan Mental Health Center from March 2018 to September 2018 were selected as the OSA group, and 92 healthy volunteers with matched age, gender and education level were also recruited as the control group. All participants were assessed by polysomnography and the montreal cognitive assessment scale (MOCA). Results: (1) The total score of MOCA, visual space/executive function score, attention score, language function score and memory score in OSA group were significantly lower than those in the control group (23±4 vs 25±4, 2.0±1.7 vs 2.9±1.5, 5.4±1.0 vs 5.7±0.7, 2.7±0.6 vs 2.9±0.3, 2.6±1.4 vs 3.0±1.4, all P<0.05). The correlation analysis showed that MOCA score was in positive correlation with education level (r=0.585, P<0.001) and mean oxygen saturation (r=0.207, P=0.020). However, the MOCA score was in negative correlation with age (r=-0.564, P<0.001) and time in bed (TIB) (r=-0.205, P=0.021). There was no correlation between MOCA score and apnea-hypopnea index (AHI) (r=-0.006, P=0.949). Multiple linear regression analysis revealed that age (t=-4.133, P<0.001), education level (t=4.001, P<0.001) and mean oxygen saturation (t=2.036, P=0.044) were the major factors that contributed to the cognitive impairment of OSA patients. Conclusions: Patients with OSA have cognitive impairment. The impairment gets more obvious when more severe hypoxia occurs at night, but it's not related to AHI.