Sleep apnea may lead to increased brain growth in the hippocampus, which could have implications for memory and cognitive function.
RT’s Three Key Takeaways:
- Increased Hippocampal Volume: A study published in Neurology found that sleep apnea may lead to increased brain growth in the hippocampus, the area responsible for memory and thinking.
- Lower Oxygen Levels Linked to Brain Changes: Lower oxygen levels during sleep were found to correlate with changes in both the hippocampus and white matter, indicating potential long-term effects on brain health.
- Implications for Cognitive Decline: The study suggests that sleep disorders, including sleep apnea, may contribute to both brain growth and damage, increasing the risk of cognitive decline and dementia, particularly in at-risk populations like Latinos.
People with breathing problems during sleep may have a larger hippocampus, the area of the brain responsible for memory and thinking, according to a study published in Neurology, the medical journal of the American Academy of Neurology.
The study, which included mostly Latino people, also found that those with lower oxygen levels during sleep had changes in the deep parts of the brain, the white matter, a common finding of decreased brain health that develops with age.
“Some studies have found sleep problems and lower oxygen levels during sleep have been linked to brain shrinkage while others have found a link to brain growth,” says study author Alberto R. Ramos, MD, of the University of Miami and Fellow of the American Academy of Neurology, in a release. “Both brain shrinkage and brain growth can harm memory and thinking by disrupting normal brain functions, increasing the risk of cognitive decline and dementia. Our study looked at Latino people, who have a higher risk of dementia when compared to non-Latino white people.”
Study Design and Methodology
The study involved 2,667 Latino people with an average age of 68. At the start of the study, each participant was given a take-home sleep test. They were divided into three groups: those who had fewer than five sleep disruptions per hour, or no sleep problems; those with five to 15 disruptions, mild sleep problems; and those with more than 15, moderate to severe sleep problems. Researchers also measured oxygen levels in the bloodstream during sleep.
Ten years later, participants had brain scans to measure brain volume and white matter hyperintensities, areas in the white matter where the brain tissue has been damaged. After adjusting for factors such as age, sex, high blood pressure, and whether a participant had insurance, they found that people in the group with the most sleep problems had 0.24 cubic centimeters (cm3) greater brain volume in the hippocampus than those with no sleep problems.
Findings and Implications
They also found that for each additional sleep disruption, there was a 0.006 cm3 increase of brain volume in the hippocampus. Researchers found lower oxygen during sleep was also associated with increased hippocampal volume as well as increased white matter hyperintensities.
“Our findings highlight the complex relationships between sleep health and brain aging and show there is a need for longer studies that follow people beginning in middle age or earlier,” Ramos says in a release. “A clear understanding of how brain volume is affected by sleep apnea and other sleep disorders is essential so people can receive early and effective treatment, especially in people who may be at higher risk for dementia.”
A limitation of the study was that it only included Latino adults, so results may not be the same for other populations.
The study was supported by the National Institute on Aging.
