A major change in how diabetes is diagnosed will mean that 2 million to 3 million Americans may learn within the next year or two that they have the disorder.
While that information may be unsettling for some, health experts say they hope the updated guidelines will serve to alert Americans to the importance of a diagnosis as early as possible. The course of many diseases can be altered if they are caught early.
The significance of early diagnosis has long been recognized for cancer and heart disease and, more recently, for osteoporosis and Alzheimer's disease.
The same is also true for diabetes, according to a report released last week by the American Diabetes Assn.
"The reason this is a major step forward is because of the prevalence of type 2 diabetes in this country," says Dr. Michael Bush, a Beverly Hills endocrinologist and representative for the American Diabetes Assn., Los Angeles chapter.
About 16 million Americans are thought to have diabetes--15.3 million have type 2; about half of those don't know they have the disease, but it is hoped the new guidelines could help identify 2 million.
The new guidelines will help doctors and patients to detect and address diabetes in its very earliest stages, Bush says.
Diabetes mellitus is a complex condition that is mainly caused by the failure of the pancreas to release enough insulin into the body. This causes sugar levels in the blood and urine to become too high, and the eyes, kidneys, nervous system and skin may ultimately be damaged.
"Our hope is that the earlier people undergo therapy, the better job we'll do preventing complications," Bush says. "There is very supportive data that you can put the disease in its place if you can do this well enough, early enough."
Adds Dr. Robert Goldstein, vice president of research for the Juvenile Diabetes Foundation: "I would hope [newly diagnosed people] are not alarmed but rather comforted in the sense that it's better to deal with it through knowledge than to remain ignorant. Better control of the diabetes is better for you."
Many individuals who find themselves newly classified as diabetic will be advised to make changes in their diet and exercise habits as a first-line approach to controlling the disease.
"With some increased physical activity--not running marathons but modest activity, say, three times a week and some weight control--the blood sugars will respond with lowering. And it is this lowering that prevents the complications," says Dr. Frank Vinicor, director of the division of diabetes at the Centers for Disease Control and Prevention in Atlanta.
The updated guidelines primarily affect adults 45 and older and include these changes:
The former terms of insulin-dependent diabetes mellitus and non-insulin dependent diabetes mellitus have been dropped because they are based on treatments that can vary and don't indicate the underlying problem. For example, many people with type 2 do take insulin.
Under the new definitions, type 1 is a disease that involves destruction of the beta cells in the pancreas that produce insulin, leading to an insulin deficiency. It usually starts in childhood but can arise at any age.
Type 2 typically arises because of insulin resistance, in which the body fails to use insulin properly, combined with a relative deficiency in the production of insulin. Type 2 generally occurs in people 45 and older who are overweight, sedentary and who have a family history of the disease.
The use of Arabic numbers replaces Roman numerals to describe the two types of diabetes.
Several diagnostic tests are available. But the guidelines recommend the use of the Fasting Plasma Glucose test, a simple blood test taken after fasting for eight hours. This is a change over the previously preferred oral glucose tolerance test, in which blood sugar levels were evaluated two hours after the individual is given a drink containing anhydrous glucose dissolved in water. The FPG is "simpler, less expensive and more acceptable to patients, and therefore, more likely to be offered on a regular basis," an ADA expert panel noted.
Cutoff Point for Diagnosis
The new cutoff point is 126 milligrams of glucose per deciliter of blood plasma--down from 140 mg. / dl. This was done because newer research shows that while patients can be asymptomatic, microvascular complications (damage to the small blood vessels) can occur in people with FPG values in the low- to mid-120s range.