A recent study has shed light on the intriguing connection between sleep apnea and changes in the brain regions associated with memory, suggesting potential implications for cognitive health. Sleep apnea, a condition characterised by repeated interruptions in breathing during sleep, affects approximately 936 million adults globally. This condition has been linked to an increased risk of various health issues, including neurological disorders such as Alzheimer’s disease.

Researchers from the University of Miami have conducted a study revealing that individuals suffering from sleep apnea may experience enlargement of the hippocampus, a critical brain area responsible for memory and learning. Additionally, the study highlights that those with lower oxygen levels during sleep exhibit alterations in the brain’s white matter, a change traditionally associated with aging-related brain issues. These findings were published in the esteemed medical journal, Neurology.

The study involved around 2,600 Latino participants, averaging 68 years of age. This demographic was chosen due to their heightened risk of Alzheimer’s disease compared to other ethnic groups, a disparity not fully explained by known risk factors. The prevalence of sleep apnea within this group also made them ideal candidates for examining early markers of brain health and disease risk.

At the outset, participants underwent a home-based sleep test to monitor the frequency of apneas—complete breathing pauses—and hypopneas—shallow breathing occurrences—during sleep. The test also measured blood oxygen levels. Based on these tests, participants were categorised into three groups: those with fewer than five sleep disruptions per hour, indicating no significant sleep issues; those with five to fifteen disruptions, classified as having mild sleep problems; and those experiencing more than fifteen disruptions, indicating moderate to severe sleep difficulties.

After a decade-long follow-up, participants received brain scans to assess brain volume and potential white matter damage. The analysis revealed that those with the most severe sleep issues exhibited a 0.24 cubic centimetres increase in hippocampal volume compared to individuals without sleep problems. Further examination indicated that each additional sleep disruption correlated with a 0.006 cubic centimetres increase in hippocampal volume.

Experts suggest that this increase in size may signify swelling due to inflammation or overall damage rather than a benign enlargement. Moreover, lower oxygen levels during sleep were linked with both higher hippocampal volume and white matter hyperintensities—areas of brain damage associated with vascular brain disease.

These findings underscore the importance of recognising and treating sleep apnea as part of an overall strategy to maintain brain health and potentially prevent dementias. Despite current treatments for dementia being marginally effective at best, addressing sleep symptoms could alleviate dementia symptoms and contribute to cognitive health.

Good quality sleep is essential for cognitive health, serving as a protective factor against various conditions. High-quality, restorative sleep enhances and protects brain function as we age. Conversely, chronic sleep disruption can lead to numerous health issues, including headaches, fatigue, and memory loss.

Disrupted sleep, as seen in disorders like sleep apnea, leads to both acute and chronic changes in the brain. Typically, a good night’s sleep facilitates repair and restoration of brain function. The glymphatic system—a specialised cleaning system within the brain—plays a crucial role during the deepest sleep stages by draining waste products generated during daily metabolism.

These findings highlight the need for further research to replicate results and explore potential treatment interventions targeting sleep apnea’s effects on brain health. Understanding the role that sleep apnea may play in dementia progression can provide valuable insights into early markers and pathways associated with vascular brain disease.

This study underscores the critical link between sleep apnea and changes in brain regions related to memory and learning. It emphasises the necessity of recognising and treating this condition to safeguard cognitive health and mitigate the risk of dementia. As dementia remains incurable, adopting strategies to address sleep symptoms is imperative for improving brain health and preventing cognitive decline.