By Katya Meyers, Dietetic Intern
We know that getting enough sleep is good for us. But, did you know that researchers have linked diabetes to poor sleep, both in terms of risk and health outcomes after a diagnosis? People that suffer from common sleep conditions, such as sleep deprivation, obstructive sleep apnea, and insomnia are at increased risk of diabetes. And, if you already have diabetes and one of these conditions, it may be more difficult to control your diabetes.
So, what does the research say about not getting enough quality sleep and the impact on your health? And, how much shut-eye should you be getting each night?
Can not getting enough sleep can increase your risk of diabetes?
The Center for Disease Control recommends adults get a minimum of 7 hours of sleep each night but reports that 1 in 3 adults all short of this recommendation (1). In the sleep lab setting, restricting sleep to 4-5 hours a night for a week results in lower glucose tolerance and insulin sensitivity. Large scale meta-analysis studies report that there is a “U-shaped association” between the length of sleep and diabetes—those getting 7-8 hours of sleep each night are at the lowest risk of having diabetes, as compared to people who sleep significantly more or less than that amount (2).
Chronic sleep deprivation can worsen blood glucose control
Another large meta-analysis showed a 1.3 fold higher increase in fasting glucose levels or hypoglycemic medications for people who reported sleeping less than 5 hours per night, as compared to a group sleeping 5-8 hours. However, more might not provide greater benefit…sleeping more than 8 hours did not seem to have any positive effect (2). Additionally, there is extensive research indicating that acute and chronic sleep deprivation is associated with poor insulin resistance in individuals with diabetes as well as those without.
Sleep deprivation can increase your cravings for junk food and lead to weight gain
Using fMRI scans, researchers from UC Berkley showed what most of us already know…a sleepless night makes us more likely to reach for pastries and pizza, not salad and whole grains. Brain scans indicated decreased activity in the frontal lobe, which governs complex behavior making, and amplified activity in the areas which are associated with more primal brain structures that control motivation. As a result, participants were more likely to reach for high calorie, high-fat foods. This may partially explain the link between obesity and lack of sleep (3).
Untreated sleep apnea can impair pancreatic Beta cells
Sleep apnea is often thought of as a side effect of obesity. However, research indicates an independent association between sleep apnea and diabetes. Hypoxia can damage pancreatic beta cells, which explains the association at least in part. Some studies show that CPAP therapy may have beneficial effects on glycemic control. Data has been mixed, however, and more research is needed in this area (2,4).
You need quantity AND quality
It’s not just how much you are sleeping, but how well you are sleeping that also must be taken into account. Reducing the amount of slow-wave sleep, without changing the total sleep time may also result in insulin sensitivity. In addition “circadian misalignment” or changing the normal sleep/wake pattern, as in shift work, may also worsen insulin sensitivity (5).
While how much sleep you need is individualized, it seems that too little sleep can significantly impact metabolic health. Research is still needed to unravel the links, but an increase in sympathetic or “flight or fight” response, higher cortisol levels, inflammation, and more cravings for junk food are all possible ways in which too little sleep leads to poor diabetes control and outcomes. Aim for at least 7 quality hours of sleep a night for optimal health and blood glucose control.