Type 2 Diabetes

Diabetes is a condition that affects the ability of the body to use glucose for fuel. Normally, an organ in the abdomen, called the pancreas, makes cells that produce insulin, a hormone. This hormone is needed to unlock cell walls and allow glucose to be used for energy. When we eat, the pancreas produces more insulin to enable the glucose circulating in the blood to be absorbed into the cells. People with type 2 diabetes either don’t make enough insulin or are unable to effectively use insulin. High levels of glucose circulate in the blood, yet the cells can’t adequately use it for energy.

The American Diabetes Association estimates 23.6 million Americans have diabetes. Type 2 is the most common form, accounting for 90 to 95 percent of all cases of the disease.

Pre-Diabetes

Type 2 diabetes doesn’t occur overnight. Many years before its onset, levels of glucose circulating in the blood are elevated, but not high enough to be considered a diagnosis of diabetes. This is called pre-diabetes.

According to the Centers for Disease Control and Prevention, about 57 million Americans are believed to have pre-diabetes. The progression to type 2 diabetes occurs slowly, typically over about 10 years. Yet, the damage to the lining of the blood vessels and organs has already begun. Over time, the excess circulating glucose can damage the cell walls and organs, increasing risk for development of heart disease and stroke.

Detecting Diabetes Risk

Most people with pre-diabetes don’t have any symptoms associated with elevated glucose levels. Therefore, health experts recommend screening for people who are at risk for type 2 diabetes.

The gold standard test for diabetes detection is the oral glucose tolerance test (OGTT, sometimes referred to as fasting glucose). The test is done after an overnight fast. Blood sugar levels are measured upon arrival at the office or laboratory. Then, the patient is given a high sugar solution to drink. Blood samples are taken every 30 to 60 minutes for up to three hours to see how much glucose is circulating in the blood. The information is compared against standardized results from people without diabetes.

More Efficient Screening?

The OGTT is an accurate and reliable screening tool for pre-diabetes and diabetes. However, it takes several hours and is costly to perform. In addition, many people dislike having to fast before taking the test.

Researchers at Emory University School of Medicine wanted to find out if they could screen for pre-diabetes and diabetes with a diagnostic test commonly used for pregnant women, called the glucose challenge test (GCT). Normally, this test is done between the 26th to 28th weeks of pregnancy to screen women for gestational diabetes, a form of diabetes that only occurs during pregnancy. Endocrinologist Lawrence Phillips, M.D. says the GCT doesn’t require an overnight fast and is much faster than the OGTT. Patients come into the office, swallow a high sugar drink and then have a blood test one hour later.

The Emory study compared the results of the OGTT and GCT in a group of nearly 1,600 volunteers. Each participant was given the GCT first and the OGTT three weeks later. The researchers found that GCT was an excellent predictor of results from the gold standard, OGTT.

Phillips says the comparison results need to be studied in a larger group of people. However, if the GCT proves to be an accurate screening tool, it would save patients time and be less costly to administer. Patients who are found to have abnormal glucose levels after the simple screen can go on to have the standard OGTT screening to confirm the presence of pre-diabetes or diabetes. If patients are found to have pre-diabetes, weight loss, diet changes, exercise and sometimes use of medications can often prevent or delay development of type 2 diabetes.

For general information on pre-diabetes, diabetes, or diabetes testing and management:

The American Diabetes Association

The National Institute of Diabetes and Digestive and Kidney Diseases