Functional connectivity in default mode network correlates with severity of hypoxemia in obstructive sleep apnea.

ABSTRACT:

Introduction

Obstructive sleep apnea (OSA)-associated hypoxemia, sleep fragmentation, and cerebral vascular dysfunction are implicated in cognitive dysfunction. Functional connectivity within default mode network (DMN) is a possible mechanism underlying the cognitive impairment. The aim of this study was to investigate the impact of hypoxemia and sleep fragmentation on functional connectivity and on cognitive performance in patients with OSA.

Methods

Twenty-eight patients with OSA were included (mean age = 58.0 ± 8.5 years). We correlated the functional connectivity in DMN with cognitive performances and further analyzed the relationship of functional connectivity in DMN with hypoxemia severity, as revealed by apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and nadir SaO₂ (%), and with degree of sleep fragmentation, as shown by sleep efficiency and wake after sleep onset.

Results

Functional connectivity in DMN was associated with AHI, ODI, and nadir SaO₂ (%) (p < .05) and was not associated with sleep fragmentation measures (p > .05). Functional connectivity that was associated with AHI, ODI, and nadir SaO₂ (%) was in the areas of bilateral middle temporal gyri, bilateral frontal pole, and bilateral hippocampus and was positively correlated with Cognitive Abilities Screening Instrument (CASI) total score (? = 0.484; p = .012), CASI-List-generating, CASI-Attention, and composite score of CASI-List-generating plus CASI-Attention (p < .05).

Conclusion

Functional connectivity in DMN is implicated in impairment of global cognitive function and of attention in OSA patients. The functional connectivity in the DMN is associated with hypoxemia rather than with sleep fragmentation.

SUBMITTER: Chang YT 

PROVIDER: S-EPMC7749584 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature