Sleep's Effect on the Body's Insulin

When you don't get enough sleep, it can make you feel groggy and cranky. But it can also result in insulin resistance that can lead to the development of type 2 diabetes, research shows. Even worse, it doesn't take long for this to happen.

In one study, when sleep was restricted to four hours a night for two nights in a row, glucose tolerance—when the body does not process glucose properly because it's not using insulin right—was reduced by 40 percent. The study, which appeared in the Journal of Clinical Endocrinol Metabolism, concluded that sleep duration is an important factor in determining insulin resistance.

"What happens in insulin resistance is that the insulin your system is making is not doing its job," explains Amy Fischl, RD, of the Kovler Diabetes Center at University of Chicago Medical Center. "The pancreas makes insulin, but it just floats around and doesn't do what it is supposed to do, which is take the glucose from the bloodstream to where it needs to go."

Insulin resistance isn't the only negative consequence of too little sleep. Eating habits can be disrupted by insufficient sleep, too, which can lead to obesity, a big risk factor for type 2 diabetes. The hormones that regulate hunger and satiety are affected by the length and quality of your sleep, explains Craig Schwimmer, MD, medical director of the Snoring Center in Dallas, Texas.

"When you're tired, you're likely to eat more," he explains. "The hormone leptin, which would normally tell you that you are full and don't need to eat anymore, stops working properly when you're not getting enough sleep."

6 Tips to Sleep Better

If you need any more reasons to start getting enough sleep, how about the fact that you'll feel better? That said, it's not always easy to slip off to dreamland. Here are some tips for getting the sleep you need:

  • Simply having too much to do is the reason most people don't get enough sleep. By the time you get home from work, make dinner, and get the kids to bed, it's probably already past your bedtime. Build a bedtime routine for yourself, not just for your kids. And that should include a period of relaxation during which you take a warm bath, if you find that relaxing, and read a good book.

  • Reserve your bed for sleep and for sex. That means not sitting in bed paying your bills or watching the 10 o'clock news.

  • Avoid electronics. Don't check email and go on Facebook just before bed. Being on the computer is too stimulating to promote the relaxation that leads to sleep, Fischl notes.

  • Manage caffeine intake. Caffeine has a "half life" of six hours, Schwimmer notes. If you have a caffeine-containing soda at 3pm, it's still in your system at 9 pm, which is when you should normally be starting to wind down.

  • Get some natural light every day. "We're supposed to sleep when it's dark and be awake when it's light," Schwimmer explains. "But if you spend all day in the office you never see the sunlight." Make it a point to get outside and spend some time in the sun each day. "This is a really powerful reinforcer of your body's circadian rhythm," Schwimmer says. 

  • Working out is great for reducing stress and staying fit, but not just before bed. Avoid vigorous exercise for about three hours before bedtime.


Esther Donga, Marieke van Dijk, J.Gert van Dijk, Nienke R. Biermasz, Gert-Jan Lammers, Klaas W. van Kralingen, Eleonara P.M. Corssmit, Johannes A. Romjin, "A Single Night of Partial Sleep Deprivation Induces Insulin Resistance in Multiple Metabolic Pathways in Healthy Subjects." Journal of Clinical Endocrinol Metabolism. June 2010, 95 (6): 2963-2968.