The TV sitcom grandpa character who always seems to fall asleep at unfortunate moments is so common it’s almost a cliché. But daytime napping and disjointed sleep at night aren’t normal parts of aging. Sleep disturbances can be an early sign of a neurodegenerative condition, and they may be treatable.
Researchers at Washington University School of Medicine in St. Louis are launching a phase 2 clinical trial to study whether using medication to treat sleep problems in older adults can reduce signs of early Alzheimer’s. A positive result would point to a new approach to delaying or preventing the onset of Alzheimer’s dementia. The trial is supported with a $7.9 million grant from the Good Ventures Foundation, a philanthropic foundation whose mission is to help humanity thrive.
“Patients may attribute poor sleep to just getting older, but we often find that they have an underlying sleep disorder,” said principal investigator Brendan Lucey, MD, an associate professor of neurology and director of Washington University’s Sleep Medicine Center. “Chronic poor sleep may put you at risk of Alzheimer’s dementia. A major goal of our research is to find out if treating the sleep problems before people have any signs of cognitive problems can slow or even stop the progress of Alzheimer’s disease.”
Alzheimer’s disease develops slowly over the course of two decades or more. First, the protein amyloid beta starts building up into plaques in the brain. Then, a second brain protein known as tau starts collecting into toxic tangles. Soon after tangles become detectable, people start to experience memory loss and confusion. Lucey and colleagues have shown that poor sleep is linked to higher levels of both amyloid and tau in the brain.
Lucey wants to determine whether a sleep drug known as suvorexant — already approved by the Food and Drug Administration (FDA) for treatment of insomnia — can intervene to slow or delay the buildup of amyloid in the brain. Suvorexant comes from a family of drugs that suppress a protein called orexin that stimulates the brain to awaken from sleep. David M. Holtzman, MD, the Barbara Burton and Reuben M. Morriss III Distinguished Professor of Neurology, has shown that another member of this drug class reduces amyloid plaques in mice.
“Suvorexant has been on the market since 2014, so we know that it’s safe and well-tolerated,” Lucey said. “We plan to use the highest dose approved by the FDA in our study.”