Poor sleep is associated with high levels of insulin resistance and difficulty controlling diabetes in people who have the condition, according to new research from the University of Chicago Medical Center.
Previous studies investigating the links between sleep and diabetes have indicated that short sleep duration increases levels of ghrelin, an appetite-stimulating hormone, can decrease glucose tolerance and stimulate production of the stress hormone cortisol, and may triple a person’s risk of developing impaired fasting glucose (IFG, a condition that leads to Type 2 diabetes and heart disease). Additionally, people who have sleep apnea are more than twice as likely as those who don’t to have diabetes, and 50% of men with Type 2 diabetes have sleep apnea.
To determine whether sleep duration and quality are associated with fasting glucose or insulin levels or levels of insulin resistance (a condition in which the body needs extra insulin to maintain normal blood glucose levels), researchers followed 40 people with diabetes and 115 people without diabetes for six nights. The participants indicated whether they had any sleep disturbances, such as insomnia, snoring, or sleep apnea, and had their blood glucose and insulin levels checked. Over the course of the study period, the participants wore activity monitors on their wrists nightly to measure wrist movements during the night. Poor sleep was determined based both on the readings from the wrist monitors (frequent wrist movement was taken as a sign of poor sleep) as well as reports from the participants that they had a hard time falling asleep or that they woke up during the night.
In people without diabetes, there was no association between poor sleep and fasting glucose or insulin levels or insulin resistance. In those with diabetes, however, the researchers found that poor sleepers had 23% higher morning blood glucose levels and 48% higher blood insulin levels. Using these numbers, it was estimated that people with diabetes who slept poorly had 82% higher insulin resistance than people with diabetes who slept well.
Kristen Knutson, PhD, lead author of the study, noted that “Poor sleep quality in people with diabetes was associated with worse control of their blood glucose levels… People who have a hard time controlling their blood glucose levels have a greater risk of complications. They have a reduced quality of life. And, they have a reduced life expectancy.” And Eve Van Cauter, PhD, one of the study’s co-authors, stated that “This [study] suggests that improving sleep quality in diabetics would have a similar beneficial effect as the most commonly used anti-diabetes drugs.”
These are all good reasons to make getting more sleep a priority, but if you’re dealing with insomnia, this advice is of course easier said than done. For tips on getting a restful night’s sleep, check out “Getting the Sleep You Need” and “Getting Back to Sleep,” both by nurse David Spero.
The next step for the researchers is to study whether treating unrefreshing sleep can improve the quality of life and long-term health outcomes for people with diabetes. Also necessary is determining whether the poor sleep leads to the insulin resistance or vice-versa.
To learn more about the research, read the article “Insomnia Linked to High Insulin Resistance in Diabetics” or see the study’s abstract in Diabetes Care.