Effects of Exercise-induced Hypoxemia on Attentional Function and Prefrontal Cortex Oxygenation in Patients with Chronic Obstructive Pulmonary Disease - Influence of Oxygen Inhalation -

Abstract

Aim of this study was to examine the effects of the exercise while breathing O2 or compress air （in a randomized and single blind fashion） on attentional function and prefrontal cortex oxygenation responses in fourteen patients with chronic obstructive pulmonary disease （COPD）．Tissue oxygenation index （TOI） and oxygenated hemoglobin （oxy-Hb） of the prefrontal cortex were measured by Near-Infrared Spectroscopy. The attentional function determined by Trail Making Test （TMT） was significantly improved from 95.6 ± 18.7（at rest） to 83.9 ± 15.9 seconds （post-exercise） with the increase of oxy-Hb on compress air inhalation. However, the improvement of attentional function in two cases with the thickness of carotid artery intima was not observed. TMT has improved significantly to 85.2 ± 19.5 seconds with the increase of TOI in the prefrontal cortex on O2 inhalation, however further improvement of attentional function is not allowed by exercise on oxygen inhalation. From these results, attentional function in patients with COPD is related to the factor of the carotid atherosclerosis in addition to exercise induced-hypoxemia.