More adults have prediabetes, with patients (and often physicians) unsure who's at risk

Confusion over who to test may be an important obstacle.

By — Posted Dec. 8, 2008

Print  |   Email  |   Respond  |   Reprints  |   Like Facebook  |   Share Twitter  |   Tweet Linkedin

There's a vast difference between the number of people the public health community places on the road to type 2 diabetes and the number of individuals who say they are aware of their perilous journey.

As many as a fourth of U.S. adults, or 54 million people, have prediabetes, according to the Centers for Disease Control and Prevention. However, just 4% of those who responded to a large CDC survey said they had been told they have this newly defined condition, which presents with impaired fasting glucose or impaired glucose tolerance or both. The findings are in the Nov. 7 Morbidity and Mortality Weekly Report.

Taking a "glass is half full" stance, the CDC and several physicians view this startling gap as an educational opportunity. After all, they note, the progression to type 2 diabetes isn't inevitable. Actions can be taken to keep the disease at bay.

Without increasing physical activity and shedding extra pounds, though, the millions of people with prediabetes are five to 15 times more likely to develop type 2 diabetes than are people with normal glucose values, according to the CDC. The agency estimates that unless steps are taken, approximately one out of every three people born in 2000 will develop diabetes in his or her lifetime.

"I want to emphasize that there is a lot that can be done to reduce the risk of developing diabetes," said Deborah Rolka, a statistician for the CDC's Division of Diabetes Translation who authored the MMWR article.

For example, the federal Diabetes Prevention Program found that making lifestyle changes could dramatically reduce the risk of developing type 2 diabetes. "We know that it takes about 30 minutes of walking five days a week, and it can reduce the risk of going on to diabetes by about 60%," said William Herman, MD, MPH, director of the Michigan Diabetes Research and Training Center at the University of Michigan Health System.

The AMA also provides advice to physicians who are helping patients lower their risk for the disease.

Among the possible reasons for the low risk awareness is that people are not being tested, Rolka suggested. She noted that prediabetes is a relatively new term, and its significance has been recognized only recently.

The CDC defines the condition as an impaired fasting glucose of 100 mg/dL to 125 mg/dL, an impaired glucose tolerance of 140 mg/dL to 199 mg/dL, or both.

"It's very much in the patient's best interest and in national health care's best interest for people to know if they are on this path," said Matt Petersen, director of the American Diabetes Assn.'s Information Resources. "There is a very significant potential public health impact here if you can improve that 4% [knowledge rate] to more than 50%."

Bridging the knowledge gap

Just how this gap emerged is likely due to the fast pace of the emerging science surrounding prediabetes, said several physicians. The group of patients to test is a moving target, and conflicting screening recommendations are making it difficult for physicians to zero in on the right patients.

The American Diabetes Assn. takes an aggressive approach and recommends including all patients with a body mass index equal to or greater than 25 kg/m and who have various risk factors. The ADA also recommends screening everyone older than age 45. However, the U.S. Preventive Services Task Force recommends screening patients whose blood pressure is greater than 135/80 mmHg.

"It's likely that more patients would be screened if the recommendations were made clearer," said Todd Brown, MD, an assistant professor in the Division of Endocrinology and Metabolism at Johns Hopkins School of Medicine in Baltimore.

Dr. Brown generally screens patients who are older, overweight or have a family history of the disease. He tends to first do an IFG test and follow with an IGT test if necessary.

But then another problem looms. Patients need to fast before taking an IFG, but since most people schedule appointments for acute care, it's not likely they have been fasting. That, however, could change if a trend toward screening patients using A1c measures catches on, said Dr. Brown.

The fact that the criteria for prediabetes changed a few years ago and now target people with lower fasting glucose levels means many more people are considered at higher risk for type 2 diabetes than had been previously, said Dr. Herman. But some physicians may not even be aware that the cut point for prediabetes has dropped to a fasting glucose level of 100 to 125 mg/dL. "So there are two issues. There are a lot more people than there were under the old criteria, and awareness is lagging behind."

In an effort to ease the decision-making process, a study was recently released on a new assessment tool designed to help determine which patients to screen. The Tool to Assess Likelihood of Fasting Glucose Impairment, or TAG-IT, was developed by Richelle Koopman, MD, an assistant professor of family medicine at the University of Missouri, and colleagues from the Medical University of South Carolina in Charleston.

The study is in the November/December Annals of Family Medicine.

TAG-IT uses six readily obtainable identifiers: age, sex, body mass index, family history of diabetes, heart rate (beats per minute) and hypertension.

The tool makes it easier to assess the combination of risk factors each patient presents, said Dr. Koopman. "Should a 22-year-old college athlete with a BMI of 26 kg/m and a family history of diabetes be tested? Should a 35-year-old sedentary woman be tested even though her BMI is 23 kg/m?"

The researchers found that TAG-IT represented an improvement over lists of risk factors and over BMI alone in identifying patients with IFG.

"Anything we can do to help identify people is going to be helpful to primary care physicians. And that is my perspective as a primary care physician," said Dr. Koopman.

Back to top


Screening for prediabetes

Researchers who developed the new Tool to Assess Likelihood of Fasting Glucose Impairment, or TAG-IT, said it represents an improvement over previous screening factors. TAG-IT assigns scores for categories within six patient characteristics to predict those who might have prediabetes. If high sensitivity is desired, a score of 5 or higher could trigger a screening. If high specificity is the goal, to eliminate false-positive results, then a score of 8 or 9 might be used.

Characteristics Score
20-27 0
28-35 1
36-44 2
45-64 4
Male 3
Female 0
Body mass index
Less than 25 0
25 to 29.9 2
30 or greater 3
Family history
of diabetes
No 0
Yes 1
Heart rate (bpm)
Less than 60 0
60-69 0
70-79 1
80-89 2
90-99 2
Greater than 100 4
No 0
Yes 1

Source: Annals of Family Medicine, November/December (link)

Back to top

Asked but not told about prediabetes

The Centers for Disease Control and Prevention included a question on prediabetes for the first time in its 2006 National Health Interview Survey. The survey is given annually to a representative sample of households. In 2006, 24,275 adults 18 and older were queried face to face.

Participants were asked: "Other than during pregnancy, have you ever been told by a doctor or health professional that you have diabetes or sugar diabetes?" If they did not respond "yes," they were asked whether they had ever been told by a doctor or health care professional that they had prediabetes, impaired fasting glucose, borderline diabetes or high blood sugar.

Prediabetes was defined as a "yes" answer to any of those questions, and 984 participants gave this response. However, since the CDC has said that a fourth of the U.S. population has prediabetes, the number should have been about 6,000.

On the bright side, among those who knew their condition, nearly 70% said they had taken action to reduce their risk of progressing to diabetes. There was no word on how successful they were in their efforts. More details about the survey and diabetes appeared in the Nov. 7 Morbidity and Mortality Weekly Report.

Back to top

External links

"Self-Reported Prediabetes and Risk-Reduction Activities -- United States, 2006, Morbidity and Mortality Weekly Report, Nov. 7 (link)

"Tool to Assess Likelihood of Fasting Glucose ImpairmenT (TAG-IT)," abstract, Annals of Family Medicine, November/December (link)

Back to top



Read story

Confronting bias against obese patients

Medical educators are starting to raise awareness about how weight-related stigma can impair patient-physician communication and the treatment of obesity. Read story

Read story


American Medical News is ceasing publication after 55 years of serving physicians by keeping them informed of their rapidly changing profession. Read story

Read story

Policing medical practice employees after work

Doctors can try to regulate staff actions outside the office, but they must watch what they try to stamp out and how they do it. Read story

Read story

Diabetes prevention: Set on a course for lifestyle change

The YMCA's evidence-based program is helping prediabetic patients eat right, get active and lose weight. Read story

Read story

Medicaid's muddled preventive care picture

The health system reform law promises no-cost coverage of a lengthy list of screenings and other prevention services, but some beneficiaries still might miss out. Read story

Read story

How to get tax breaks for your medical practice

Federal, state and local governments offer doctors incentives because practices are recognized as economic engines. But physicians must know how and where to find them. Read story

Read story

Advance pay ACOs: A down payment on Medicare's future

Accountable care organizations that pay doctors up-front bring practice improvements, but it's unclear yet if program actuaries will see a return on investment. Read story

Read story

Physician liability: Your team, your legal risk

When health care team members drop the ball, it's often doctors who end up in court. How can physicians improve such care and avoid risks? Read story

  • Stay informed
  • Twitter
  • Facebook
  • RSS
  • LinkedIn