Sleep on This: Lack of Shut-Eye Ups Diabetes Risk

By  Denise Mann

WebMD Medical News (edited)

Reviewed By  Gary Vogin, MD

June 25, 2001 (Philadelphia)

Need another reason to get your Zs? Well, here’s one: People who don’t get adequate

rest may increase their risk for type 2 diabetes, the most common form of the disease, according to research presented

here at the annual meeting of the American Diabetes Association.

In a nutshell, lack of sleep puts undue stress on the body. The body, in turn, releases a torrent of stress hormones that

interfere with the way blood sugar, or glucose, is processed.

As a result, inadequate sleep may lead to the development of insulin resistance, a pre-diabetes state in which the cells

do not respond to insulin appropriately, so the sugar in the blood cannot get into the cells.

In a study of 27 people, “short-sleepers," or those who slept less than 6.5 hours per night, were about 40% less insulin-

sensitive than normal sleepers, those who logged about 7.5 to 8.5 hours a night.

“It’s a real possibility that one of the causes of the epidemic of diabetes and obesity is related to short sleep habits,” says

lead researcher Eve Van Cauter, PhD, professor of medicine at the University of Chicago.

That’s not good news considering that a majority of American adults -- 63% --fail to get the recommended eight hours in

the sack, according to statistics from the National Sleep Foundation. Consider that in 1910, Americans averaged about

nine hours of slumber per night, and now they’re getting less than seven hours.

“And sleep loss may worsen diabetes in people with disease,” she says.

The next step is to see if extending sleep helps people with type 2 diabetes or those with higher than normal -- but not

quite diabetic -- blood sugar levels, a condition called impaired glucose tolerance. This three-year study is slated to

begin in September. Half of all patients will extend their sleep by three hours per night, while the others will learn about

the importance of regular sleep habits.

“Americans are the most sleep-restricted society,” she says, attributing this to people working multiple jobs, having long

commutes, juggling family responsibilities, and being bombarded by round-the-clock television and Internet channels.

Her advice? “Watch your sleep the same way that you watch your exercise and nutrition. We are not biologically wired

for sleep deprivation,” she tells WebMD. “If you have to work long hours, try to make up for it over the weekend.”

Researchers measured sleep with watch-like monitors that detect sleep and movement and headbands that monitor

movements of the head and the eyelid during sleep.

The new findings make perfect sense to John Buse, MD, PhD, director of the Diabetes Care Center at the University of

North Carolina at Chapel Hill.

“Sleep deprivation is a state of stress, and stress worsens insulin sensitivity.” Anything that increases stress can affect

diabetes risk, he says.

About 16 million Americans have diabetes. In just the past decade, there’s been a 40% increase in diabetes in the U.S. -

- and a 70% increase among people in their 30s. Most of the increase is in type 2 diabetes, the form of the disease that

is linked to obesity.

The link between sleep and weight loss most people don’t know about...

A combination of diet and exercise is usually the method of choice for people who want to control their weight. Strange as it might

sound, there’s also a growing body of evidence to show that better sleep habits are instrumental to the success of any weight loss plan.

A fascinating series of studies published in the Journal of the American Medical Association and the Lancet show that sleep loss

disrupts a series of complex and interwoven metabolic and hormonal processes. This can make weight loss far more difficult than it needs

to be.

When most people hear the word “hormone”, they think of the sex hormones, such as testosterone or estrogen. Yet these are just

two of the many hormones that regulate virtually everything your body does. Hormones have the power to change the way your fat cells

respond to the food you eat. Specifically, sleep loss affects levels of cortisol, growth hormone and insulin.

Weight loss

Cortisol is a hormone released by your adrenal glands in response to either physical or emotional stress. Whether it’s an extremely

low calorie diet, missed nights of sleep, or getting caught in a traffic jam, your body responds in much the same way. When you deprive

your body of sleep, cortisol levels tend to rise, especially in the evening. This, in turn, raises insulin levels. Insulin promotes a metabolic

environment that encourages the storage of fat.

Picture the scene. You come home from work late in the evening. Not only have you been having trouble sleeping, work is also

causing stress. So you decide to eat something that will make you feel better.

Consider the type of food people crave when they feel stressed — rich in refined carbohydrate and sugar. Combine a stress-induced

chocolate binge with elevated levels of cortisol and insulin, and you have the perfect recipe for weight gain.

Sleep deprivation, even for as little as 24 hours, can also lead to signs of insulin resistance. Insulin resistance means that the ability

of insulin to dispose of glucose in the liver and other tissues is reduced.

Scientists point to insulin resistance as the “trigger” for a host of health problems, including obesity, cardiovascular disease, and type

II diabetes. Insulin resistance is the cumulative effect of poor eating and lifestyle habits. In fact, there is evidence that rats show signs of

insulin resistance after just two weeks on a high-fat, high-sugar diet.

A decline in slow wave sleep (this is the “deep” sleep known for its restorative properties) is also linked with reduced levels of growth

hormone. This hormone plays an important role in fat loss and muscle growth.


Further evidence linking body weight and sleep comes from a study of 814 men and 958 women from the Mediterranean area of

Spain. Carried in the International Journal of Obesity, the study shows that people who sleep for more than nine hours each day are less

likely to be overweight than those sleeping for six hours or less. Based on their findings, the authors conclude that the odds of obesity are

24% lower for each additional hour you spend asleep.

The results also show that people watching TV for more than four hours each day were more likely to be obese than those watching

TV for less than one hour. In fact, the odds of obesity are 30% higher for each hour you spend in front of the TV.

Of course, this research doesn’t mean that sleeping for less than six hours each night is a guarantee that you’ll put on weight. Nor

does it mean that sleeping for longer is the answer. As with many things, the relationship between sleep and fatigue is probably U-shaped.

The same holds true with many nutrients, where excess amounts can be toxic. But if you don’t get enough, your health suffers. In other

words, too little, as well as too much sleep is not healthy.

What’s most important is to recognize that a healthy lifestyle involves balancing work and rest in a way that suits you. Getting

enough sleep and rest is just as important as what you eat and how you exercise.