[Influences of severe obstructive sleep apnea on cognitive function].

To explore the differences in cognitive function between patients with severe OSA and non-moderate OSA. The MoCA scale was used to evaluate the overall cognitive function and sub-items in 196 subjects who received polysomnography; and the SDMT and TMT-A scales were used to evaluate the performance in test of attention and information processing speed in 161 patients. The clinical information, physical examination data and related polysomnography data were collected. According to AHI, subjects were divided into two groups: severe OSA and non-to-moderate OSA. Before and after correction of confounding factors, the differences in cognitive scale evaluation indicators were compared between the two groups. We used linear regression analysis to clarify the independent influencing factors of cognitive functions, and to determine whether severe OSA is independently related to cognitive abilities. After correcting for multiple factors, the delayed recall score and total score of the MoCA scale and the correct number of SDMT in the severe OSA group were significantly lower than those in the non-to-moderate OSA group（<0.05）. Linear regression analysis showed that severe OSA was independently negatively correlated with the delayed recall score, total score and SDMT correct number in the MoCA scale（<0.05）. Compared with non-to-moderate OSA, subjects with severe OSA have significant decline in overall cognition, delayed recall, attention and processing speed. Severe OSA may be an independent influencing factor of overall cognition, delayed recall, attention and processing speed.