Chronic hypoxemia is a major mechanism that can adversely
affect cognitive performance and hippocampal
volume [27-30]. In this study, we also examined the relationships
between hippocampal volume and relevant
factors in mild-to-moderate and severe COPD groups,
respectively. We found that hippocampal volume was positively
correlated with the level of PaO2 in both mild-tomoderate
and severe COPD groups. In addition, it was
positively associated with SaO2 in mild-to-moderate COPD
group. These findings show that the chronic hypoxemia in
COPD patients may induce hippocampal atrophy, which
plays a crucial role in cognitive impairment