Defining Diabetes

Type 1 and Type 2 Diabetes
Before Diabetes: IGT

If you have been diagnosed with diabetes, you are one of about 17 million Americans who live with this disease on a daily basis. Perhaps you understand that proper diet and exercise can lessen the symptoms and long-term impact of the disease.

Diabetes is characterized by an abnormally high concentration of blood sugar. In normal metabolism, the hormone insulin helps carry glucose into fat, muscle, and skeletal cells. If this process is disrupted, the body can respond in various ways. In certain cases, untreated diabetes can cause the pancreas to produce an overabundance of insulin, setting in motion a cascading series of abnormal metabolic responses. In others types of diabetes, cells actually can starve to death.

For decades, medical researchers have distinguished the causes, symptoms, and treatments of two major types of diabetes--Type 1, also known as insulin-dependent diabetes, and Type 2, or noninsulin dependent diabetes.

Type 1 patients, who typically develop the disease as children or young adults, are unable to produce insulin. Their symptoms--high levels of sugar in their blood and urine, frequent urination, extreme hunger, thirst, and weight loss, weakness, and nausea--often develop quickly. Individuals with Type 1 diabetes control the disease with daily insulin injections, exercise, and diet.

Type 2 diabetes constitutes the most common form of the disease with over 80 percent of diabetic patients suffering from this "adult onset" form. A typical Type 2 patient is over 45 years old and overweight. Type 2 patients do not produce enough insulin or are unable to make proper use of the insulin they do produce. Although certain symptoms are similar to Type 1 (tiredness, irritability, nausea, possibly increased appetite), Type 2 diabetes develops more slowly and thus can develop undetected for some time.

The precise causes of both types of diabetes are unknown, but in many patients, genetic factors seem to play a role in the manifestation of the disease.

During recent years, doctors have further refined the definition of Type 2 diabetes to better detect people who lack symptoms but may be developing the disease. Broadening the definition of diabetes will enable medical professionals to help patients begin managing their lifestyle and possibly forestall future health complications.

Before Diabetes: IGT

Ask anyone who has just been diagnosed with diabetes how they feel, and you are likely to hear a list of symptoms that includes extreme thirst, frequent urination, and exhaustion. But recently, diabetes specialists have been treating people who may be headed for diabetes, yet experience none of these symptoms.

They identify individuals with impaired glucose tolerance (IGT)--blood sugar levels that are higher than normal but not high enough to be diagnosed as diabetes.

People with IGT used to be considered "borderline" or "pre-diabetic." Now specialists consider impaired glucose tolerance a distinct condition that needs to be identified and managed.

Nearly 20 million Americans have impaired glucose tolerance--many of them unknowingly. Higher than normal blood sugar levels before breakfast, plus an array of risk factors may indicate that you fit the profile for impaired glucose tolerance. Individuals with this condition are at greater risk of developing diabetes (particularly Type 2 diabetes).

Fortunately, identifying individuals with IGT is fairly simple. A blood sugar test before eating breakfast is all it takes. The test should be considered for individuals with the following risk factors:

• you had diabetes when you were pregnant
• you had a baby weighing more than nine pounds
• you are overweight
• you have high blood pressure or high cholesterol levels
• you are Native American, African American, or Latino

If the screening process indicates you have IGT, your health care provider can work with you to establish goals for diet, exercise, and overall health that can help you reach and maintain normal blood sugar levels.

Last Reviewed 2005

Source: Division of Endocrinology and Metabolism
Department of Internal Medicine
The University of Iowa

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.