People who have sleep apnea and spend less time in deep sleep are more likely to have brain biomarkers linked to an increased risk of stroke, Alzheimer’s disease and cognitive decline, according to new research.
However, the study does not prove that these sleep disturbances cause changes in the brain, or vice versa. It only shows one association.
Mayo Clinic researchers found that for every 10-point decrease in the percentage of slow-wave sleep, there was an increase in the number of white matter hyperintensities, a biomarker visible as tiny lesions on brain scans, consistent with the effects of sleep deprivation. Being the same 2.3 years old.
The same deficit was also associated with reduced axonal integrity, which forms the nerve fibers that connect nerve cells, similar to the effect of being three years older.
People with severe sleep apnea had higher amounts of white matter hyperintensity than those with mild or moderate sleep apnea. They also had reduced axonal integrity in the brain.
The researchers accounted for age, sex and conditions that could affect the risk of brain changes, such as high blood pressure and high cholesterol.
The findings were published in the medical journal Neurology.
“These biomarkers are sensitive signs of early cerebrovascular disease,” said Diego Z. Carvalho, from the Mayo Clinic in Minnesota and a member of the American Academy of Neurology.
“Finding that severe sleep apnea and reductions in slow-wave sleep are associated with these biomarkers is important because there is no cure for these changes in the brain, so we need to find ways to prevent them from happening or getting worse.” ”
The study included 140 people with obstructive sleep apnea, with an average age of 73, who underwent brain scans and were studied overnight in a sleep lab.
The participants did not have cognitive issues at the start of the study and did not develop dementia by the end of the study.
A total of 34 percent had mild, 32 percent had moderate and 34 percent had severe sleep apnea.
“More research is needed to determine whether sleep issues affect these brain biomarkers or vice versa,” Carvalho said. “We also need to see whether sleep quality improvement or sleep apnea treatment strategies can affect the trajectories of these biomarkers.”