March 14, 2001 -- Many chronic diseases have warning signs that appear years before the actual disease itself, but often these signs are so subtle they are easily missed. In the case of diabetes, for example, slight changes in blood sugar, if detected early enough, could help doctors intervene before diabetes develops.
In a study published in the March issue of Diabetes Care, researchers from New Zealand and the U.K. say two routine lab tests can help doctors detect very early signs of an important risk factor for diabetes. The tests diagnose insulin resistance.
Insulin resistance is a condition where the body has a decreased response to insulin, a hormone important in the regulation of blood sugar. While not everyone with insulin resistance will develop diabetes, it is enough of a risk factor that doctors recommend people who test positive for insulin resistance make some changes in their lifestyle. Typically, those changes include losing weight and becoming more physically active.
The most effective way of detecting insulin resistance involves complicated equipment that is restricted mainly to use in research laboratories and is not practical for the typical doctor to use in his or her office.
But in the new study, the researchers say the results of two relatively simple tests added together could provide enough information for doctors to diagnose insulin resistance in an office setting. The tests measure the amount of insulin in the blood after fasting and the amount of triglycerides, which are an indicator of the level of food-derived fat in your blood.
The researchers, led by Kirsten A. McAuley, of Otago University in Dunedin, New Zealand, say having such testing readily available makes it more likely that early efforts to prevent diabetes will be successful.
But some doctors say that even though the combination of tests sounds like an easy solution for diagnosing insulin resistance, insulin levels are notoriously unreliable because they vary significantly from person to person and from men to women.
"I just think unless there is a uniform method for measuring insulin, it can actually confuse you more than help you," says Om Ganda, MD, who reviewed the study for WebMD.
The American Diabetes Association has recommended setting up centers for standardizing insulin tests to reduce the risk of variable results. But so far, no such centers exist.
Ganda says another problem is that even when insulin resistance is diagnosed, doctors can't tell patients with any certainty whether they will eventually develop diabetes. All they really can do, he says, is recommend they reduce risk factors -- like obesity, high blood pressure, and inactivity -- that are known to lead to diabetes.
According to the National Institute of Diabetes and Digestive and Kidney Diseases, approximately 16 million people in the U.S. have diabetes, the most common cause of blindness, kidney failure, and amputations in adults.