A new study found a link between sleep-disordered breathing and larger hippocampal size. The findings demonstrate the complex relationships between sleep health and brain aging. The study was published in Neurology.
Sleep-disordered breathing includes several conditions that cause abnormal breathing during sleep, such as snoring and obstructive sleep apnea, which is when a person stops breathing five or more times per hour. The condition is a risk factor for stroke and Alzheimer's disease.
Hispanic/ Latino adults have a higher risk of sleep-disordered breathing as well as Alzheimer's disease and related dementia, making it critical to understand the link between these two conditions for this population in particular.
In the current study, researchers investigated the link between sleep-disordered breathing and brain MRI measures in the Hispanic/ Latino population. The study included data from 2,667 participants with an average age of 67.6 years old who underwent neuroimaging around 10 years after an initial sleep assessment.
Ultimately, 56% of the participants had no sleep problems, 28% had mild sleep problems, and 16% had moderate to severe sleep problems. The researchers found that participants with the most severe sleep problems- characterized by more than 15 sleep disruptions per hour- had a 0.24-cubic-centimeter larger hippocampal volume than those without sleep problems.
They additionally found that each additional sleep disruption correlated with a 0.006 cubic centimeter increase in hippocampal brain volume and that lower oxygen during sleep was linked to increased white matter hyperintensities- areas in the white matter where brain tissue has been damaged.
"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," said study author, Alberto R. Ramos, MD, Professor of Clinical Neurology at the University of Miami and Fellow of the American Academy of Neurology in a press 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," he added.
In their paper, the researchers concluded that their results warrant longitudinal follow-up, starting in middle age or earlier.
Sources: Science Daily, Neurology