People experiencing breathing issues while asleep might possess a larger hippocampus, the brain region linked to memory and cognition, as indicated by recent research. This study, primarily involving Latino participants, revealed that individuals with lower oxygen levels during sleep exhibited alterations in the brain’s deep regions, particularly the white matter, which is often associated with reduced brain health that occurs with aging.
Recent findings suggest that individuals with breathing difficulties during sleep may have a larger hippocampus, the brain section responsible for memory and cognitive functions. This conclusion comes from a study published on December 18, 2024, in the online edition of Neurology®, the official journal of the American Academy of Neurology. The research predominantly examined Latino individuals and identified that those with lower oxygen levels while sleeping experienced changes in the brain’s deep areas, particularly the white matter, typically indicative of declining brain health with age.
Breathing disorders during sleep encompass various conditions that disrupt normal respiratory patterns, such as snoring and obstructive sleep apnea. In obstructive sleep apnea, a person may pause breathing five or more times within an hour, leading to reduced oxygen levels that can impact brain function.
“Some research has indicated that sleep issues and lowered oxygen during the night may correlate with brain shrinkage, while other studies suggest a connection to brain growth,” explained Dr. Alberto R. Ramos, the study’s author from the University of Miami and a Fellow of the American Academy of Neurology. “Both types of changes, brain shrinkage and growth, can negatively affect memory and cognitive abilities, increasing the likelihood of cognitive decline and dementia. Our focus was on Latino individuals, who are known to be at a higher risk for dementia compared to non-Latino white individuals.”
The study encompassed 2,667 Latino participants, averaging 68 years of age.
Initially, each volunteer completed a home sleep evaluation that assessed the frequency of breathing interruptions, termed apneas, and instances of slow or shallow breathing, referred to as hypopneas.
Participants were categorized into three groups based on sleep disruptions: those with fewer than five disturbances per hour (indicating no sleep problems), those with five to 15 disturbances (mild sleep issues), and those experiencing over 15 disruptions (moderate to severe problems). Among the participants, 56% reported no sleep issues, 28% faced mild difficulties, while 16% dealt with moderate to severe problems.
Researchers also monitored oxygen levels in the bloodstream during sleep.
After ten years, participants underwent brain imaging to evaluate overall brain volume and white matter hyperintensities, which represent areas where brain tissue has sustained damage.
After accounting for variables such as age, gender, high blood pressure, and whether participants had health insurance, researchers discovered that those in the highest sleep problem group had a hippocampal volume that was 0.24 cubic centimeters (cm3) larger compared to those with no sleep issues.
Additionally, it was observed that for every sleep disruption, there was a corresponding increase of 0.006 cm3 in hippocampal volume. The study also found that lower oxygen levels during sleep correlated with enlarged hippocampal volume and increased white matter hyperintensities.
“Our results underscore the intricate connections between sleep quality and brain aging, indicating the necessity for extended studies tracking individuals from middle age or younger,” noted Ramos. “Understanding how sleep apnea and various sleep disorders influence brain volume is crucial for facilitating early and effective treatment, especially for those at heightened risk of dementia.”
A limitation of this study was its focus solely on Latino adults, suggesting that outcomes may differ in other demographic groups.
The research received funding from the National Institute on Aging.
