Trouble sleeping might be an early sign of Alzheimer’s disease

MINNEAPOLIS — People who suffer from sleep problems are more likely to be diagnosed with Alzheimer’s disease than those who rest soundly at night, a recent study found.

Researchers at the University of Wisconsin-Madison found links between sleep disturbances and the common biological markers for Alzheimer’s disease found in spinal fluid.

“Previous evidence has shown that sleep may influence the development or progression of Alzheimer’s disease in various ways,” says study author Dr. Barbara B. Bendlin, of the University of Wisconsin–Madison, in a press release by the American Academy of Neurology . “For example, disrupted sleep or lack of sleep may lead to amyloid plaque buildup because the brain’s clearance system kicks into action during sleep. Our study looked not only for amyloid but for other biological markers in the spinal fluid as well.”

Amyloid is a protein that can clump up and fold into plaques. Tau is another protein that can form tangles in the brain. Both of these proteins are telltale signs of Alzheimer’s disease.

For the study, Dr. Bendlin’s team recruited 101 people (about 63 years old on average) who were all considered at-risk for Alzheimer’s disease — either having a parent suffering from the disease or being a carrier of the gene that increases the risk of Alzheimer’s symptoms. They were surveyed for sleeping habits or difficulties, and provided spinal samples tested for known biological markers of the disease.

Those participants who reported more sleeping problems, worse sleep quality, and daytime sleepiness had more biological markers indicating Alzheimer’s disease than those who didn’t report any sleep troubles.

Not everyone with sleep abnormalities or troubles had biological markers related to Alzheimer’s in their spinal fluid. Even when the researchers adjusted their study for factors like the use of medications for sleeping problems, signs of depression, amount of education, and body mass index, the results stayed the same.

“It’s still unclear if sleep may affect the development of the disease or if the disease affects the quality of sleep. More research is needed to further define the relationship between sleep and these biomarkers,” says Bendlin. “There are already many effective ways to improve sleep. It may be possible that early intervention for people at risk of Alzheimer’s disease may prevent or delay the onset of the disease.”

The full study was published in the American Academy of Neurology’s journal Neurology.