All Americans older than age 45 - a third of the population - should have their blood sugar screened to find unsuspected cases of diabetes, top experts said Monday in an unprecedented attempt to get the devastating disorder diagnosed early.
The panel convened by the American Diabetes Association also lowered the blood sugar threshold for diabetes on the preferred diagnostic test, which means 2 million more people would be considered diabetic.
The redefinition is the first revision of diabetes diagnosis and terminology in 18 years. It is expected to make a profound difference in the way the disease is detected and treated worldwide.
The old blood sugar threshold, 140 milligrams of glucose per deciliter of blood, missed many people with early signs of diabetic damage to tiny blood vessels, according to recent research. The new level, 126 milligrams, will pick up millions more cases at a stage when that damage might be prevented or delayed by many years.
Federal health officials, who endorsed the change, said at a Boston meeting of the Diabetes Association that it could raise the number of Americans diagnosed with diabetes from 8 million to 10 million, with vast implications for their health status, lifestyle and medical care.
The goal is to identify diabetes much earlier than it usually is, then take steps to lower elevated blood sugar through diet and exercise, and, when those fail, with pills and insulin shots. That in turn should prevent or delay the serious complications of diabetes - progressive blindness, kidney disease, nerve damage, heart disease and stroke.
“We feel passionately that people need to take diabetes more seriously,” said Dr. James Gavin III, chairman of the Diabetes Association panel, which made the change after a two-year study. “Just because diabetes doesn’t hurt doesn’t mean it isn’t hurting you.”
Dr. Richard S. Beaser of the Joslin Diabetes Center, which has endorsed the change, noted that diabetes goes undiagnosed for seven to 10 years after it begins, according to one widely accepted study.
“Oftentimes diabetics will present for the first time with a heart attack, which is tragic,” Beaser said. “If we can get a seven- to 10-year jump on preventing complications, it will make an enormous difference.”
The World Health Organization will shortly adopt the new definition - minus the screening recommendation, which will be left up to individual nations - said Dr. K. George Alberti of the University of Newcastle in England, who directs the WHO’s human diabetes and metabolic research center. Alberti noted that diabetes already affects 150 million people around the world, and the incidence is doubling every three or four years in China and India due to better diagnosis and more affluent lifestyles.
The new guidelines urge doctors to abandon a widely used diagnostic test called the oral glucose tolerance test in favor of a simpler and less expensive fasting plasma glucose test. The glucose tolerance test, which costs around $125, requires patients to drink a sugar-rich liquid and abstain from exercise or any food or beverage intake for two hours. A blood sample is then taken.
The fasting plasma glucose tests costs $5 to $10 and requires only that a patient’s blood be sampled after an overnight eight-hour fast.
Because it is simpler and cheaper, federal health officials expect that the fasting test will be administered more often. That, plus the lowered test threshold for making a diabetes diagnosis, could move two million Americans with diabetes from the “undiagnosed” to the “diagnosed” column.
An estimated 16 million Americans have diabetes, but about half do not know it. The total number of diabetics is not expected to change, only the proportion of those who are diagnosed - as a result of wider use of the preferred test. About 15.3 million Americans have type 2 diabetes, which typically begins in adulthood. Another 700,000 have type 1 diabetes, which usually begins in childhood.
The recommendation that 89 million adults over age 45 be tested for diabetes represents the first time the Diabetes Association or federal health authorities have made such an across-the-board recommendation. Younger individuals should also be screened if they are at risk for diabetes because a close relative had the disease, they are more than 20 percent over their ideal weight, or they belong to an ethnic group with a higher risk - African-American, Hispanic, Native American or AsianAmerican.
Others considered at high risk include women who have delivered a baby weighing more than nine pounds or those who developed gestational diabetes; individuals with blood pressure over 140/90; those with low levels of HDL cholesterol or high levels of triglycerides; and those who have had blood glucose levels close to the new threshold.
The Diabetes Association panel dropped a prior recommendation that all pregnant women be tested for diabetes; white women under age 25 with normal weight and no family history no longer need testing.
The panel urged doctors to abandon the terms “insulin-dependent diabetes mellitus” and non-insulin-dependent diabetes mellitus” for type 1 and type 2 diabetes, since these reflect types of treatment rather than underlying causes.
MEMO: This sidebar appeared with the story: DIABETES GUIDELINES Among the new guidelines: Every adult should have a diabetes test every three years starting at age 45. Those who get a high reading should have the test repeated on another day. Those at higher than usual risk may need to be tested earlier or more often. These people include American Indians, blacks, Asians, Hispanics and anyone who is overweight or has high blood pressure, high cholesterol or a strong family history of the disease. The cutoff for declaring someone diabetic should be lowered from the current 140 milligrams of glucose per deciliter of blood plasma to 126. Doctors should abandon the categories of insulin-dependent and non-insulin-dependent diabetes. Insulin-dependent, which once was called juvenile diabetes, should be termed type 1. Non-insulin-dependent, traditionally known as adult-onset diabetes, should be called type 2. Contrary to earlier recommendations, pregnant women do not need to be tested routinely if they are white, under age 25 and of normal size and have no close family members with the disease.