From loud snoring to chronic daytime fatigue, and increased irritability to an inability to focus, the physical and mental effects of sleep apnea have long been known. Less understood, and more challenging to observe, are the chemical effects of sleep apnea in the brain.
A recent study , however, shines some light on this otherwise dark corner of sleep apnea. The research indicates that the breathing interruptions associated with sleep apnea have a profound impact on the brain chemicals gamma-aminobutyric acid (GABA) and the much-easier-to-pronounce glutamate.
How GABA Works
GABA is a neurotransmitter, a chemical that acts as a messenger in the transmission of signals. But what kinds of signals does GABA carry?
GABA, which resides in the central nervous system, has an inhibitory, calming effect on brain activity. It helps your body and mind relax, preparing it for sleep and maintaining it in a sleeping state. GABA receptors–structures on brain cells that accept GABA–are possibly the most numerous in your brain, showing the important role that GABA plays in helping to regulate your body’s excitation. People who have difficulty producing GABA or binding it to the appropriate receptors can experience high levels of anxiety.
GABA and Glutamate
Glutamate and GABA have a kind of yin-yang relationship. GABA is actually produced from glutamate, the two have almost opposite effects.
While GABA slows brain activity, glutamate acts as an accelerator. Together, the two chemicals help maintain balance. But the new research suggests that sleep apnea causes dramatic fluctuations in GABA and glutamate, and influences the brain’s ability to function properly.
GABA, Glutamate, and Sleep Apnea
Scientists at UCLA found that sleep apnea triggers a drop in GABA and a spike in glutamate. The result is a wild ride for the brain — and an unrestful night — in those who suffer from sleep apnea.
Of particular concern to researchers is whether these wild swings in the levels of two important brain chemicals, which recur night after night in people with sleep apnea, may cause long-term damage.
“In previous studies, we’ve seen structural changes in the brain due to sleep apnea,” said lead researcher and UCLA professor Paul Macey in a press release announcing the study’s publication in the Journal of Sleep Research , “but in this study we actually found substantial differences in these two chemicals that influence how the brain is working.”
Researchers, according to Macey, expected to witness an increase in glutamate because glutamate in high amounts has been shown to contribute to brain damage; long-term, untreated sleep apnea has also been linked to brain damage. “What we were surprised to see was the drop in GABA,” Macey said. “That made us realize that there must be a reorganization of how the brain is working.”
Sleep Apnea Is Treatable
Although the dangers of sleep apnea are real, the silver lining in this somewhat dark cloud is that sleep apnea is treatable, and its potentially deadly health risks are avoidable.
CPAP, a device that helps maintain an open airway during sleep, has long been the standard in sleep apnea management. While CPAP is an effective treatment, some patients find the associated mask cumbersome and uncomfortable.
Another successful sleep apnea treatment option is a customized oral appliance. These devices are designed to fit comfortably in a patient’s mouth during sleep to provide an optimal jaw position and promote an open, continuous airflow. Many people who have difficulty with CPAP find an oral appliance a much more comfortable treatment option.