People who suffer disrupted sleep in midlife can develop memory problems a decade later, a new study has revealed. And the findings could help research into the prevention of Alzheimer’s disease. Those in their 30s and 40s who struggle to sleep well are more likely to also struggle with thinking and memory tasks in their 40s and 50s.
“Given that signs of Alzheimer’s disease start to accumulate in the brain several decades before symptoms begin, understanding the connection between sleep and cognition earlier in life is critical for understanding the role of sleep problems as a risk factor for the disease. Our findings indicate that the quality rather than the quantity of sleep matters most for cognitive health in middle age,” said study author Dr. Yue Leng, of the University of California, San Francisco.
The study published in Neurology, the medical journal of the American Academy of Neurology, looked at 526 people with an average age of 40 who were followed for 11 years. Participants slept for an average of six hours and wore a wrist activity monitor for three consecutive days, twice, approximately a year apart to calculate their averages. They also reported bedtimes and wake times in a sleep diary and completed a sleep quality survey with scores ranging from zero to 21, with higher scores indicating poorer sleep quality. A total of 239 people, or 46 percent, reported poor sleep with a score greater than five.
They also completed a series of memory and thinking tests. The worst type of sleep was known as ‘sleep fragmentation’ when sleep is frequently interrupted for short periods. Of the 175 people with the most disrupted sleep, 44 had poor cognitive performance 10 years later, compared to 10 of the 176 people with the least disrupted sleep.
After adjusting for age, gender, race, and education, people who had the most disrupted sleep had more than twice the odds of having poor cognitive performance when compared to those with the least disrupted sleep. There was no difference in cognitive performance at midlife for those in the middle group compared to the group with the least disrupted sleep. The authors emphasized that the study does not prove that sleep quality causes cognitive decline but only shows an association.
“More research is needed to assess the link between sleep disturbances and cognition at different stages of life and to identify if critical life periods exist when sleep is more strongly associated with cognition. Future studies could open up new opportunities for the prevention of Alzheimer’s disease later in life,” said Dr. Leng.
Produced in association with SWNS Talker
