Sleep and Diabetes: The Secret Link

Medically Reviewed by Michael Dansinger, MD on December 01, 2015
From the WebMD Archives

Researchers are studying the link between shut-eye and diabetes. What they’re finding is that how you sleep -- how well, how little, or how long -- can help determine whether you get the disease or not.

One recent study found that too much sleep can put you at greater risk for type 2 diabetes. The CDC estimates that the disease could end up affecting 1 out of every 3 people in their lifetime.

Another study found that too little rest disrupts your body’s “circadian” rhythm. Think of this as your biological clock. If you disturb it, your body becomes less responsive to insulin, a hormone the helps your cells turn sugar into energy. When that happens, it can lead to diabetes.

Doctors aren’t sure why poor sleep habits can lead to the disease. But one thing is clear: It's a wise idea to get quality shut-eye and make it habit.

Uncovering the Links

A 2015 study in the journal Diabetologia looked at more than 59,000 women ages 55-83.

“What we found were two really key findings. One was that those women who were persistently short-sleepers - that is, less than 6 hours a night of sleep - had an increased risk for diabetes,” says researcher Susan Redline, MD. “But, actually, one of the novel findings was those women who actually increased their sleep by 2 hours or more at night ... they also had an increased risk of diabetes.”

When the researchers charted the link between bad sleep and diabetes, they saw that participants who got too little rest and those who got too much both had a higher odds of getting the disease.

“The real question is why?” Redline says.

It’s not hard to come up with reasons.

“I look at my college years. When we stayed up all night, the food that we tended to gravitate toward were which ones? The fattier foods, the carbohydrate-rich foods,” says Marina Chaparro, RDN, a nutritionist from Miami. “And we know we're definitely not wanting to exercise the day that you have 4 or 5 hours of sleep.”

But the study in Diabetologia accounts for many of those factors, like changes in diet and weight and a lack of physical activity. Even then, the researchers found that those who slept too much or too little still came up with an increased risk for diabetes.

So something else may well be at work to explain why poor sleep patterns lead to a greater risk of diabetes.

A Break in Rhythm, Leftovers From Childhood

Researchers at the University of Colorado found that short sleep breaks the body’s natural rhythms.

They simulated a 5-day work week with nights of 5 hours of sleep. They included times that subjects were wide awake and eating when they should’ve been sleeping. Next, they noted when participants’ melatonin levels were highest. (Melatonin is a hormone that helps regulate sleep.) Normally, that’s when you’re supposed to be asleep. But scientists found that if it stayed high after the subjects woke up, their bodies were less sensitive to the effects of insulin. In fact, it was 20% lower.

Doctors also found that if participants ate when they should've been asleep, they might also have a higher risk of diabetes.

“We found the longer you are awake during the biological night, the worse your insulin sensitivity is,” Kenneth Wright, the study’s lead researcher, wrote in a press release. “This is important because impaired insulin sensitivity can lead to both prediabetes and type 2 diabetes.”

For younger people, a lack of quality sleep leads to an even greater risk of diseases, including diabetes.

“There also may be critical developmental points early in life, or critical susceptibility points ... that may actually cause certain disturbances in metabolism, even something that we call reprogramming of your metabolism,” Redline says. “It may be that as you are a short sleeper earlier in life, you are more likely to develop visceral fat - fat around your abdomen - and that's what kind of fat we see associated with diabetes and heart disease.

“It may be that as you get older, and you try to catch up with sleep, you haven’t really overcome the fact that earlier in life, you've developed a certain type of body habit, or a certain trajectory for weight gain, or you've reprogrammed some of your cells.”

Ideal Sleep

Seven to 8 hours a night is the goal, most experts say. It varies depending on age. Infants, toddlers, and teens need more sleep.

Knowing how much sleep is healthy is one thing. Getting it on a regular basis is another. Especially when all sorts of obstacles often stand in the way, from a snoring bed partner, to chronic diseases like sleep apnea or depression, to the TV blaring, to your work schedule, even to that spicy taco you had for dinner.

“I think what is well understood -- and you don't need a health care professional degree to realize this -- is that Americans, in general, underestimate the importance of sleep and its benefits to health and, actually, your quality of life,” says Kellie Antinori-Lent, a diabetes clinical nurse specialist in Pittsburgh.

How to Get There

“We're all going to have some nights of not enough sleep,” Chaparro says.

She suggests using blackened windows or heavy drapes to keep out all light. A little bedtime snack, like an apple or yogurt, might keep you from getting up in the middle of the night, too.

Antinori-Lent suggests you keep the TV out of the bedroom -- read a book to help you wind down.

Also. go to bed at the same time and get up at the same time -- experts say that's key to keeping your body’s clock on track.

The National Sleep Foundation offers these tips to help you sleep soundly:

  • Stick to a relaxing bedtime routine.
  • Avoid naps that can throw off your rhythm.
  • Exercise regularly.
  • Keep your room between 60-67 degrees.
  • Sleep on a good mattress and pillows.
  • See your doctor if you still have trouble getting good Zzz's. A lack of shut-eye, or trouble falling asleep, could be a sign of another condition, like sleep apnea.

“We not only have to think about how much [we] sleep but when we sleep,” Redline says, “and that there's this intersection, or even possibly synergy, between our sleep duration and our circadian rhythms. And that having a misaligned rhythm, especially in connection with not getting enough sleep, may be a double whammy on the metabolic system.”

If that's the case for you, then “you don’t have to take medication," Antinori-Lent says. "You just have to develop a healthy habit.”

WebMD Feature



Susan Redline, MD, professor of sleep medicine, Harvard Medical School.

Marina Chaparro, nutritionist, pediatric endocrinology, Joe DiMaggio Children's Hospital, Miami; spokesperson for the Academy of Nutrition and Dietetics.

Kellie Antinori-Lent, nutritionist, diabetes clinical nurse specialist, University of Pittsburgh Medical Center-Shadyside Hospital, spokesperson for the American Association of Diabetes Educators.

Colorado Arts & Sciences Magazine: “Lack of Sleep Impairs Insulin Sensitivity.”

National Sleep Foundation: “How Much Sleep Do We Really Need?”

Cespedes, EM. Diabetologia, published online November 2015.

Eckel, R. Current Biology, published online November 2015.

© 2015 WebMD, LLC. All rights reserved.
Click to view privacy policy and trust info