If you’re a light sleeper you may have a bigger risk of Alzheimer’s. The amount and quality of sleep you get at night seems to affect your memory later in life, according to research being presented at the American Academy of Neurology’s 64th Annual Meeting in New Orleans April 21 to April 28, 2012.

“Disrupted sleep appears to be associated with the build-up of amyloid plaques, a hallmark marker of Alzheimer’s disease, in the brains of people without memory problems,” says study author Yo-El Ju, M.D. “Further research is needed to determine why this is happening and whether sleep changes may predict cognitive decline.”

Researchers tested the sleep patterns of 100 people between the ages of 45 and 80 who were free of dementia. Half of the group had a family history of Alzheimer’s disease. A device was placed on the participants for two weeks to measure sleep. They also filled out sleep diaries and questionnaires.

After the study, it was discovered that 25 percent of the participants had evidence of amyloid plaques, which can form years before the symptoms of Alzheimer’s disease begin. The average time a person spent in bed during the study was about eight hours, but the average sleep time was 6.5 hours due to persistent awakenings.

The study found that people who woke up more than five times per hour were more likely to have amyloid plaque build-up compared to people who didn’t wake up as much.