Deep sleep shortage and sleep apnea: tied to stroke and Alzheimer’s risk?

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Do you snore heavily and feel tired even after a full night’s sleep? You might have sleep apnea, a common but serious sleep disorder.

Recent research published in Neurology suggests that people with sleep apnea who get less deep sleep may be at a higher risk for conditions like stroke, Alzheimer’s disease, and cognitive decline.

However, it’s important to note that the study doesn’t say sleep issues cause these brain changes or vice versa. It only shows a connection.

Understanding the Connection

The study focused on sleep factors and certain markers related to brain health.

Specifically, it looked at the health of the brain’s white matter, which connects different parts of the brain. It used two key markers: white matter hyperintensities and axonal integrity.

White matter hyperintensities are tiny spots on brain scans that become more common as we age or if we have high blood pressure.

Axons form the nerve fibers that connect nerve cells. Together, these markers can help understand early cerebrovascular disease.

Who Took Part in the Study

The research involved 140 people, average age 73, who had obstructive sleep apnea. Each of them had a brain scan and an overnight sleep study.

None of them had cognitive issues at the start of the study or developed dementia by the end of it. The sleep apnea in participants ranged from mild to severe.

The Role of Deep Sleep

One focus of the sleep study was slow-wave sleep, also known as deep sleep. This is often considered a key sign of good sleep quality.

The researchers discovered that for every 10-point drop in the percentage of slow-wave sleep, there was a rise in the amount of white matter hyperintensities.

This effect was similar to being 2.3 years older. The same decrease also linked to reduced axonal integrity, equivalent to the effect of being three years older.

Sleep Apnea and Brain Health

People with severe sleep apnea had more white matter hyperintensities than those with mild or moderate sleep apnea. They also showed reduced axonal integrity in the brain.

To make sure their findings were accurate, the researchers considered factors like age, sex, and conditions that could affect the risk of brain changes, such as high blood pressure and high cholesterol.

What’s Next?

According to Dr. Diego Z. Carvalho from the Mayo Clinic, we need more research to understand whether sleep issues impact these brain markers or vice versa.

Studies could also explore if improving sleep quality or treating sleep apnea can influence these markers.

Limitations of the Study

The study’s design had one limitation. It observed participants’ sleep until they were diagnosed with obstructive sleep apnea, mostly in the first two to three hours.

After that, they used a positive airway pressure machine for the rest of the night. As a result, the sleep measurements might not reflect a full night’s sleep.

If you care about brain health, please read studies about vitamin D deficiency linked to Alzheimer’s and vascular dementia, and higher magnesium intake could help benefit brain health.

For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and coconut oil could help improve cognitive function in Alzheimer’s.

The study was published in Neurology. Follow us on Twitter for more articles about this topic.

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