Diabetes Prevention
For: A Cluster of Problems—and
Solutions, April 2003
Diabetes is about to become a concern for millions of middle-aged Americans who never gave it much thought before. The American Diabetes Association, backed by federal health authorities, recently called for routine screening of all Americans starting at age 45, using a simple, inexpensive test, in order to detect more cases of Type 2 diabetes earlier. This form of diabetes, previously called non-insulin dependent or adult-onset diabetes, accounts for 90 to 95% of cases of diabetes. Until now, the disease has generally been diagnosed when people develop symptoms, such as unusual thirst or frequent urination, or when people at high risk for the disease (such as those with a family history of it) are tested for it. Now blood sugar testing may become as routine as blood pressure screening.
At the same meeting, the Association issued new guidelines
that lower the cutoff points between normal, borderline, and high (diabetic)
levels of blood sugar (see chart at right). That, combined with widespread
screening, is expected to identify an additional 2 million Americans as
diabetics. It's estimated that 14 to 16 million have diabetes, but half
have not been diagnosed. And the half that have been diagnosed typically
have the disease for seven years before it is diagnosed. Experts hope
that early detection will identify cases when they are still mild. It's
hoped that this way, before symptoms develop, people can take steps to
minimize the subtle damage to organs and blood vessels caused by years
of high blood sugar levels, and avoid later complications of diabetes,
such as heart disease, hypertension, stroke, and diseases of the eyes,
nerves, and kidneys, which often lead to premature death.
Diabetes is a breakdown in the body's ability to utilize glucose (blood sugar) efficiently. Glucose, the main sugar into which foods are digested, can be used by our cells only in the presence of the hormone insulin. With Type 2 diabetes, the cells become resistant to the effects of insulin, and thus blood levels of glucose rise. (With Type 1, which is usually diagnosed in young people, the body virtually stops producing insulin.) The incidence of Type 2 diabetes is on the rise, largely because the U.S. population is aging and getting heavier.
The new guidelines
• If you are 45 or over, you should be tested every three years.
• You should be tested earlier and more frequently if you
— are obese (more than 20% above healthy body weight). The obesity rate has risen dramatically during the past two decades and now includes one-third of Americans.
— have a parent or sibling with diabetes.
— are black, Hispanic, or Native American, or belong to another high-risk ethnic group.
— gave birth to a baby weighing more than nine pounds, or developed gestational diabetes during pregnancy.
— have high blood pressure (140/90 or higher).
— have an HDL ("good") cholesterol level of 35 or below and/or a blood triglyceride level of 250 or higher.
• The ADA recommends the fasting plasma glucose test (no food for eight hours before) because it is simplest, cheapest (about $10), and most likely to be utilized on a regular basis. The same vial of blood drawn for the test can also be used to measure cholesterol and for other standard blood work, if needed.
• A result of 126 mg/dl (milligrams of glucose in one-tenth liter of blood) or more, confirmed on a second day, means you have diabetes. The former guidelines set the cutoff at 140. Researchers now believe that serious problems linked to diabetes begin with test results in the mid-120s.
| BLOOD SUGAR (mg/dl) |
|
DIAGNOSIS |
| Less than 110 | Normal | |
| 110-125 | Impaired fasting glucose | |
| 126 and above (twice) | Diabetes |
• If you are diagnosed with diabetes in its early stages, you'll be advised to lose weight if you're overweight, exercise more, improve your diet (choose the same low-fat, semi-vegetarian diet that is known to lower the risk of heart disease and cancer), and quit smoking if you smoke. The goal of early detection is to avoid diabetes medications, or at least postpone or minimize their use, not merely to start drug therapy earlier.
• If your result is between 110 and 125, you fall into a new category called "impaired fasting glucose," a danger zone or borderline area. This means that you should take the same steps as outlined above, since blood sugar levels tend to rise with age. Here is where it may truly be possible to prevent diabetes.
Last words: Unfortunately, there's no clear evidence that earlier treatment with drugs will reduce the long-term complications of Type 2 diabetes (though it does for Type 1). In any case, if screening for diabetes serves as an additional incentive for people to make life-style changes (such as losing weight and exercising), that can only be beneficial.
UC Berkeley Wellness Letter, October 1997