Chronic obstructive pulmonary disease (COPD) is the collective term for a group of lung conditions that cause long term breathing difficulties. It is a common condition affecting mainly middle-aged or older adults who smoke, with symptoms including breathlessness and a chesty ‘smokers’ cough. Individuals with COPD are at higher risk of dementia – one current theory suggests that this is due to lower brain oxygen levels as a result of problems with blood supply from blood vessels in the brain. In line with this theory, some studies have reported that giving COPD patients additional oxygen reduced their risk of developing dementia. However, until now, the mechanisms underlying this positive effect had not been fully investigated.
The research team found that blood flow and oxygen delivery to the brain was significantly increased during reading. This was due to blood vessels in the brain becoming dilated in response to the greater oxygen demand when the brain was active. It can thus be concluded that when COPD patients receive additional oxygen it improves the function of blood vessels in their brain.
This study showed that providing extra oxygen improves the function of blood vessels in the brain by matching blood supply to the demands of the brain activity. However, COPD patients typically use this extra oxygen therapy throughout the day and for long periods of time, potentially years. This study does not indicate the influence of long term oxygen therapy on the function of blood vessels in the brain. Despite these potential limitations, this work has set the foundation for the researchers to investigate the biological systems that control oxygen delivery to the brain.