Prediabetes guidelines' aim: Avoiding heart risk
■ Steering clear of early microvascular damage is the goal of a new consensus statement that addresses elevated blood glucose levels.
By Susan J. Landers — Posted Aug. 18, 2008
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Washington -- A finding of prediabetes has triggered alarms recently, primarily because it often is a precursor to type 2 diabetes. Now, the somewhat ambiguous condition has treatment recommendations of its own.
The American College of Endocrinology and the American Assn. of Clinical Endocrinologists released a consensus statement July 23 on the diagnosis and management of prediabetes, a condition estimated to affect about 54 million adults in the United States, according to the Centers for Disease Control and Prevention. This number compares with about 24 million who have diabetes.
A person with prediabetes is five to 15 times more likely to develop type 2 diabetes than is someone without the condition, said the Agency for Healthcare Research and Quality in 2005.
But prediabetes is not just a predictor of trouble ahead; it carries its own risks, according to a panel of 17 experts convened by the two groups and sponsored by several pharmaceutical companies that market drugs to control blood glucose levels.
"This is an area where it is increasingly clear that we can see the beginnings of the characteristic end-organ complications of diabetes that may ultimately lead to blindness, kidney failure or amputation," said Alan J. Garber, MD, PhD, chair of the panel that wrote the guidelines and a professor of medicine, biochemistry and molecular biology and molecular and cellular biology at Baylor College of Medicine in Houston.
The microvascular complications that cause such severe health problems for people with diabetes have their start in this prediabetic stage, Dr. Garber said. These complications also trigger excess cardiovascular risk, he noted, which is a major health issue for diabetics.
People with prediabetes have fasting glucose levels of 100 to 125 mg/dL, or impaired glucose tolerance levels of 140 to 199 mg/dL. Some have both. Diabetes is diagnosed at a fasting level of 126 mg/dL and an impaired tolerance rate of 200 mg/dL.
Since normal glucose rates are defined as fasting levels less than 100 mg/dL and impaired glucose tolerance rates less than 140 mg/dL, a sizeable chasm exists between normal and diabetic. It is this space the groups are targeting.
"We don't mean to create a brand-new illness, but we mean to draw attention to this gap between what is clearly normal and what is disease," said AACE Vice President Daniel Einhorn, MD, clinical professor of medicine at the University of California, San Diego and medical director of the Scripps Whittier Institute for Diabetes in La Jolla, Calif.
Lifestyle changes and beyond
Diabetes is not the only disease for which lower numbers are best. Hypertension kicked off that trend a few years ago with a new category of prehypertension. Ideal LDL scores also have been on a downward trajectory.
So when it comes to advice, the new statement falls in line with the recommendations for those other harbingers of disease -- make lifestyle changes. Even modest losses of 7% to 10% of body weight can result in decreased fat mass, blood pressure, glucose, low-density lipoprotein and triglyceride levels.
A program of moderately intense physical activity for 30 to 60 minutes each day at least five days a week is also recommended, as is a low-fat diet with adequate dietary fiber.
But the statement goes beyond these steps. "We all agree that lifestyle is the first way to go, but we have to recognize that in those at the highest risk, lifestyle might not be enough," said Yehuda Handelsman, MD, medical director of the Metabolic Institute of America, in Tarzana, Calif., a diabetes research and education facility. He also served on the panel that drafted the statement.
While acknowledging that no medications have been approved by the Food and Drug Administration for the treatment of prediabetes, the panel recommends that metformin and acarbose be considered for patients at particularly high risk, such as those with worsening glycemia or cardiovascular disease.
Their statement also recommends that physicians check fasting plasma glucose, hemoglobin A1c levels and lipids every six months.
ACE inhibitors and angiotensin receptor blockers should be considered first-line treatments. Thiazides and beta-blockers, which have adverse effects on glycemia, should be used with caution, according to the statement.
Aspirin also is recommended for those with no excess risk of gastrointestinal complications or hemorrhagic conditions.
Although bariatric surgery is effective at reducing the risk for diabetes in patients who are morbidly obese, the panel did not recommend surgery for those with prediabetes.
The move to treat patients at risk for diabetes earlier has the potential to lower substantially the costs associated with the disease, the panel said. The explosion of obesity and diabetes in the nation is reflected in an enormous burden on the health care system, with an annual estimated cost of $174 billion, Dr. Garber said.
With costs high and expected to grow in coming years, something had to be done, Dr. Garber said. "In light of that, we decided to try to formulate a systematic attempt to deal with it."