The researchers suggest the findings could help explain why sleep apnea patients have symptoms that affect their daily lives, but they could not prove that the altered levels of brain chemicals actually cause thinking and memory problems.
The researchers analyzed levels of glutamate and gamma-aminobutyric acid (GABA) in the brain. These chemicals are found in the part of the brain known as the insula, which helps coordinate signals from other brain areas to regulate emotions, thinking, and certain physical functions.
The researchers found that sleep apnea patients have lower levels of GABA and abnormally high levels of glutamate. GABA is a mood regulator that helps keep things calm and mellow, but glutamate, on the other hand, does the opposite. High levels of glutamate stress out the brain, which doesn’t then function properly.
Macey added, “It is rare to have this size of difference in biological measures. We expected an increase in the glutamate, because it is a chemical that causes damage in high doses and we have already seen brain damage from sleep apnea. What we were surprised to see was the drop in GABA. That made us realize that there must be a reorganization of how the brain is working.”
Macey concluded, “What comes with sleep apnea are these changes in the brain, so in addition to prescribing continuous positive airway pressure, or CPAP, a machine used to help an individual sleep easier … physicians now know to pay attention to helping their patients who have these other symptoms. Stress, concentration, memory loss — these are the things people want fixed.”
Future studies will explore whether the treatment for sleep apnea could also help normalize brain chemicals.