Do people with sleep apnea have inferior cognitive function?
A 2018 study at the University of Illinois at Chicago College of Medicine published in the journal Acta Diabetologica found that people who do not get enough sleep and who are living with diabetes or pre-diabetes have less cognitive function than those who get enough sleep.
“When you’re living with sleep apnea, you have a greater chance of developing diabetes,” said Dr. Darin Ward, a Dallas, Texas, orthodontist.
Sleep apnea is a sleep breathing disorder in which individuals stop breathing during sleep. The condition affects more than 22 million Americans, many of whom are undiagnosed. Researchers estimate that 80 percent of those affected have obstructive sleep apnea, or OSA, a type of sleep apnea caused by blockages of the airway.
“The airway can be blocked by the tongue or the muscles of the throat, which collapse when the body relaxes during sleep,” Ward said.
Individuals living with sleep apnea have a higher risk of developing diabetes because they do not reach the stage of sleep in which hormones like insulin are controlled.
“When insulin isn’t controlled, it affects the body’s glucose tolerance, which contributes to high blood sugar and diabetes,” Ward said.
Earlier studies have found that there is a link between diabetes and cognitive impairment and an increased risk of dementia. Previous studies have also connected diabetes to cognitive impairment.
During the study, researchers analyzed 162 participants to investigate the relationship between sleep and cognitive function in patients with abnormal glucose tolerance. The researchers also examined connections between those with sleep problems and clinically diagnosed diabetes.
Half of the patients had Type 2 diabetes, and half had pre-diabetes.
The average age of participants in the group was 54.8 years.
Researchers measured both sleep duration and sleep efficiency, a measure of how much time is spent sleeping. The measurements were recorded for each individual on the study for seven days through actigraphy recordings. An actigraph is a device worn on the wrist that measures motion; during sleep studies, it is used to record periods without movement.
The researchers also used a questionnaire known as the Montreal Cognitive Assessment, or MoCA. All participants were also assessed for OSA.
The average sleep duration was six hours per night, and the average sleep efficiency was 82.7 percent.
While they found that how long people slept in conjunction with how severe an individual’s sleep apnea case were not related to changes in cognitive function determined by the MoCA, researchers did find that greater sleep efficiency was associated with better cognitive function scores for individuals with pre-diabetes and diabetes.
Additionally, they also found that having diabetes meant that cognitive function scores were lower.
The researchers on the project hope that future studies can help determine if treatment can improve cognitive function.
Source: University of Illinois at Chicago. “Poor sleep linked to lower cognitive functioning in people with diabetes and pre-diabetes.” ScienceDaily. ScienceDaily, 6 June 2018.