Intriguing Links Between Sleep Apnea and Alzheimer's
Investigators have found additional evidence of a connection between obstructive sleep apnea (OSA) and cognitive impairment. The findings, which were published in 2018 in the American Journal of Respiratory and Critical Care Medicine, show that as the severity of OSA increases, so do levels of amyloid plaque—a hallmark of Alzheimer's.
The 208 study participants, ages 55 to 90, were healthy and cognitively normal. Slightly more than half had mild, untreated OSA. Investigators followed participants for two years, initially measuring concentrations of amyloid in their spinal fluid and repeating the test at the study's conclusion. They also viewed amyloid deposits in participants' brains using PET (positron emission tomography) scans and monitored their OSA with a home sleep recording device. OSA is characterized by repeated starts and stops in breathing, abrupt awakenings, and excessive snoring.
At the end of the study, both amyloid deposits in the brain and biomarkers for amyloid plaque in the spinal fluid of those with OSA had increased in proportion to the severity of their condition. The authors say that if the results are confirmed, "clinical interventions for OSA may be useful in preventing amyloid build-up in cognitively normal elderly."
While it's too early to know if treating sleep apnea can help prevent amyloid build up, and thus, reduce the risk of dementia, continuous positive airway pressure (CPAP) can help people with OSA breathe better at night and feel more alert during the day.