Howstuffworks "Introduction to Causes of Type 1 Diabetes"

If you have type 1 diabetes, the chances are pretty good that you have known it for a long time: Half of all people diagnosed with type 1 diabetes are younger than 20 years old. In fact, type 1 diabetes used to be called juvenile-onset diabetes, though doctors eventually decided that name is inaccurate since it can strike anyone, at any age. Another alternative name is insulin-dependent diabetes, since virtually all folks with type 1 require injections of the crucial hormone. Only about 5 to 10 percent of all people with diabetes have type 1 diabetes, making it far less common than type 2 diabetes.

Type 1 diabetes begins with a glitch in the immune system, the body's defense against bacteria, viruses, and other microscopic nasties that roam around inside your body, trying to make you sick. The immune system is a complex network of vessels, fluids, white blood cells, and proteins called antibodies that patrol your innards, looking for things that don't belong. When your immune system detects a germ or anything else that is not recognized as part of the body, it fires off white blood cells and antibodies to engulf and destroy the intruder.

Unfortunately, in some people the immune system is guilty of friendly fire. It mistakes perfectly innocent and otherwise healthy body tissue for an enemy invader, attacking it with an onslaught of voracious immune cells. Depending on what part of the body your immune system attacks, the result can be one of many autoimmune diseases, which include rheumatoid arthritis, lupus, thyroiditis, and, yes, type 1 diabetes.

The next section will cover how your immune system can affect your body's insulin production.

For even more valuable information on Type 1 diabetes, try the following links:

To learn more about diabetes in general, including diagnosis, causes, symptoms, and treatment, visit our main Diabetes page
Our main Type 1 Diabetes page gives a thorough overview of this form of diabetes, commonly called "juvenile diabetes."
Learn the diverse signs of type 1 diabetes, from increased thirst and hunger to sudden weight loss, in Symptoms of Type 1 Diabetes.
For a variety of treatment options, read Treatment for Type 1 Diabetes.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

Type 1 Diabetes and Insulin

In the case of type 1 diabetes, your immune system unleashed an assault on the cells in your pancreas that make insulin, which are known as beta cells. As your beta cells died off, your insulin production slowed down, and it may have even stopped. Without sufficient amounts of insulin to control the amount of glucose in your blood, your blood glucose levels began to rise, causing symptoms of diabetes. The symptoms likely included

an unquenchable thirst. You could guzzle an entire Super Big Gulp soda and still feel parched.
a frequent need to urinate. Duh, you're probably thinking, of course I'll be racing for the bathroom if I'm drinking so much. But with type 1 diabetes your bladder may feel ready to burst whether you've been imbibing fluids or not.
increased hunger. But don't worry about getting fat; see next item.
sudden weight loss. Now you might be thinking, Do you mean I get to eat like a pig and lose a few pounds? Sign me up! Not so fast. Type 1 diabetes causes weight loss because your body is more or less devouring itself. And you know that can't be good.
unexplained fatigue. As in your whole body, not just your jaws from all that eating.

©2007 Publications International, Ltd.
Increased hunger is a symptom of type 1 diabetes, but so is sudden weight loss.

It's easy to see from these diverse symptoms just how important insulin is to the human body. Read on to learn how your body responds when glucose starts to build up in the bloodstream.

For even more valuable information on Type 1 diabetes, try the following links:

To learn more about diabetes in general, including diagnosis, causes, symptoms, and treatment, visit our main Diabetes page
Our main Type 1 Diabetes page gives a thorough overview of this form of diabetes, commonly called "juvenile diabetes."
Learn the diverse signs of type 1 diabetes, from increased thirst and hunger to sudden weight loss, in Symptoms of Type 1 Diabetes.
For a variety of treatment options, read Treatment for Type 1 Diabetes.

Type 1 Diabetes and Glucose

When glucose has no way of entering your cells, the sugary substance starts to build up in the blood. Your body has to pull water out of the blood (increasing thirst) so that it can get rid of the excess glucose in the urine (which explains the frequent trips to the restroom). Your cells are screaming for fuel (triggering the "Let's order another pizza!" instinct in your brain). While they're waiting for more glucose, your cells switch to alternate sources of energy, so the body starts to run on fat. That's the reason you lose weight, but it's kind of like burning the furniture in the fireplace when you can't pay the heating bill. And the combination of high blood glucose levels and dehydration makes you feel tired.

Burning fat all day instead of glucose isn't just inefficient; it can be life threatening if it goes on too long. As your body breaks down fat to use as energy, it produces leftover products called ketones. Does that word ring a bell? You may have heard of ketones and ketosis (the accumulation of ketones when fat is burned for energy) if you have tried the carbohydrate-hating Atkins diet. In his book Dr. Atkins' Diet Revolution, the late Robert Atkins, M.D., claimed that ketosis is "a signal for rejoicing...a state devoutly to be desired...." Why? Because, according to Atkins, it means you're burning unsightly fat and shedding flab!

Obesity experts disagree whether intentionally triggering ketosis is a safe and effective weight-loss method, though many diet doctors insist that some people lose weight on the Atkins plan not because of metabolic trickery but because it's just another low-calorie diet. (Studies have failed to show that it's superior to other weight-loss approaches.)

What's not up for debate is whether high levels of ketones are dangerous for the person with diabetes. Normally, these compounds pass harmlessly from your system into urine to be excreted. But when carbohydrates are entirely removed from the diet--or when glucose can't get into cells, as in advanced diabetes--ketones build up to toxic levels. At first your breath has a weird odor, like fruit-flavored paint thinner. But soon you become confused, short of breath, and nauseous. You feel dehydrated and lose your lunch. If you don't get medical attention ASAP, you slip into a coma from which you may never awaken. Since you're taking care of your diabetes, you'll likely never have to worry about this condition, called ketoacidosis.

In our final section, we will look at what exactly makes all of these changes happen inside your body.

For even more valuable information on Type 1 diabetes, try the following links:

To learn more about diabetes in general, including diagnosis, causes, symptoms, and treatment, visit our main Diabetes page
Our main Type 1 Diabetes page gives a thorough overview of this form of diabetes, commonly called "juvenile diabetes."
Learn the diverse signs of type 1 diabetes, from increased thirst and hunger to sudden weight loss, in Symptoms of Type 1 Diabetes.
For a variety of treatment options, read Treatment for Type 1 Diabetes.

Genetics and Type 1 Diabetes

Some people inherit their mother's freckles or father's bald spot. If you have type 1 diabetes, there's a good chance one of your parents passed along to you an abnormal gene or cluster of genes that puts you at greater-than-average risk for developing the condition. (For those of you who were busy dozing or passing notes during high school biology class, everyone inherits a blend of genes from both parents that not only determines what you look like but also greaty influences your health.)

Being born with these genes doesn't guarantee that you will develop type 1 diabetes, however. These inherited genes only make you susceptible to developing diabetes. Something elsehas to trigger changes in your body to create your blood sugar problem. But what?

©2007 Publications International, Ltd.
While your family history makes you susceptible to
type 1 diabetes, it is not the only factor.

Scientists aren't sure, but they have a short list of suspects. According to one theory, a virus or some environmental toxin worms its way into the body and confuses the immune system because it resembles proteins found on beta cells. The immune system tends to shoot first and ask questions later, so it destroys anything that looks like it could be a threat--including insulin-producing beta cells in the pancreas. Type 1 diabetes occurs more often in people who have had a viral illness, as these can trigger the onset of type 1 diabetes in a susceptible individual.

Other scientists have speculated that switching a baby from breast milk to cow's milk too early is the culprit. However, the dairy-diabetes connection remains controversial. In fact, in 2003 a pair of studies in the Journal of the American Medical Association found no connection between consuming cow's milk and diabetes. Some causes are more clear-cut. For example, certain prescription medications can trigger type 1 diabetes.

Whatever the cause, type 1 diabetes is a serious condition. Fortunately, it can be managed. Make sure you and your doctor monitor your diabetes carefully to avoid the risk of the complications like the ones discussed in this article.

For even more valuable information on Type 1 diabetes, try the following links:

To learn more about diabetes in general, including diagnosis, causes, symptoms, and treatment, visit our main Diabetes page
Our main Type 1 Diabetes page gives a thorough overview of this form of diabetes, commonly called "juvenile diabetes."
Learn the diverse signs of type 1 diabetes, from increased thirst and hunger to sudden weight loss, in Symptoms of Type 1 Diabetes.
For a variety of treatment options, read Treatment for Type 1 Diabetes.

ABOUT THE AUTHORS:

Timothy Gower is a freelance writer and the author of several books. His work has appeared in many magazines and newspapers, including Prevention, Health, Reader's Digest, Better Homes and Gardens, Men's Health, Esquire, Fortune, The New York Times, and The Los Angeles Times.

ABOUT THE CONTRIBUTORS

Dana Armstrong, R.D., C.D.E., received her degree in nutrition and dietetics from the University of California, Davis, and completed her dietetic internship at the University of Nebraska Medical Center in Omaha. She has developed educational programs that have benefited more than 5,000 patients with diabetes. She specializes in and speaks nationally on approaches to disease treatment, specifically diabetes.

Allen Bennett King, M.D., F.A.C.P., F.A.C.E., C.D.E. is the author of more than 50 papers in medical science and speaks nationally on new advances in diabetes. He is an associate clinical professor at the University of California Natividad Medical Center and cofounder and medical director of the Diabetes CareCenter in Salinas, California.