According to recent research, those who have more sleep disturbances in their 30s and 40s may be more susceptible to memory and cognitive issues ten years later.
The study, which was written up in the journal Neurology, does not establish a link between poor sleep and cognitive deterioration. It merely displays a correlation.
“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,” said Yue Leng, from the University of California, San Francisco.
“Our findings indicate that the quality rather than the quantity of sleep matters most for cognitive health in middle age,” Leng added.
The average age of the 526 participants in the study was 40. They had an 11-year follow-up.
Participants’ sleep duration and quality were observed by researchers. To determine their averages, participants wore a wrist activity monitor for three days in a row, twice, almost a year apart. On average, each participant slept for six hours.
In addition, participants filled out a sleep diary recording their wake and bedtimes, and they scored zero to 21 on a questionnaire measuring the quality of their sleep; higher numbers denoted lower quality sleep. A total of 239 individuals, or 46%, gave a score of more than five for bad sleep.
Participants also completed a series of memory and thinking tests.
Researchers also looked at sleep fragmentation, which measures repetitive short interruptions of sleep. They looked at both the percentage of time spent moving and the percentage of time spent not moving for one minute or less during sleep.
After adding these two percentages together, researchers found that participants had an average sleep fragmentation of 19 per cent.
Researchers then divided participants into three groups based on their sleep fragmentation score.
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.
Individuals with the highest levels of sleep disruption had over twice the likelihood of experiencing impaired cognitive function compared to those with the least amount of sleep disruption, even after controlling for age, gender, race, and educational attainment.
When comparing the middle group’s cognitive ability at midlife to the group experiencing the least amount of sleep disruption, there was no difference.
Source:SE