Andrew Stiles and Collin Anderson of the Washington Free Beacon respond to a recent medical revelation involving President Biden.

President Joe Biden began using a CPAP machine “in recent weeks” to treat the sleep apnea he has suffered from since at least 2008, ABC News reported Wednesday. This new detail about Biden’s health, revealed after observers noticed an unusual indentation on his face, suggests the octogenarian president has put himself at increased risk of dementia and cognitive decline.

Biden has suffered from sleep apnea since at least 2008, when Politico reported that Biden “has suffered from atrial fibrillation, or an irregular heartbeat,” which doctors said was probably “linked to Biden’s reoccurring problem of sleep apnea.” Dr. Joseph Krainin, M.D., a medical advisor at SleepApnea.org, told the Washington Free Beacon that Biden likely suffered from “a certain type of sleep apnea where his brain forgets to breathe during sleep.”

There is no mention of sleep apnea in White House physician Dr. Kevin O’Connor’s summary of the president’s health following Biden’s most recent physical in February. Biden’s medical records from 2019 revealed that he had several surgeries on his sinus and nasal passage. But surgeries do not always cure patients’ sleep apnea, and patients may still need to use a CPAP machine after undergoing an operation, according to Alberta Health Services.

Failing to treat his sleep apnea with a CPAP machine—for more than a decade—may have put Biden at increased risk for dementia, studies show.

That’s because untreated sleep apnea leads to intermittent oxygen deprivation in the brain, causing certain brain cells to die. Those brain cells are among the same cells “that we know die in dementia,” according to Australian neuroscientist Elizabeth Coulson. As a result, Coulson and her coauthors found in a recent study, untreated sleep apnea can lead to increased risk of dementia.