Undiagnosed diabetes, IFG rates are still a problem

Improvements needed in diagnosing diabetes to reduce rate of undiagnosed disease.

Issue: July 2006

As several high-profile studies have shown, the prevalence of diagnosed diabetes has increased significantly over the last decade. But according to a new study from the National Institutes of Health, the prevalence of undiagnosed diabetes and impaired fasting glucose have remained relatively stable during this same period.

Catherine Cowie, PhD, director of the diabetes epidemiology program at the National Institute of Diabetes and Digestive and Kidney Diseases, led the recent study examining the prevalence of diagnosed and undiagnosed diabetes and impaired fasting glucose. Cowie and her colleagues used data from the National Health and Nutrition Examination Surveys to determine the current prevalence rates and compare these rates with those of a decade earlier.

In the most recent NHANES study, conducted between 1999 and 2002, the rate of diagnosed diabetes was 6.5%. The rate of undiagnosed diabetes was 2.8% and the rate of impaired fasting glucose was 26%.

The researchers compared this data with results from an earlier NHANES study conducted between 1988 and 1994. At that time, the rate of diagnosed diabetes was 5.1%, the rate of undiagnosed diabetes was 2.7% and the rate of impaired fasting glucose was 24.7%.

Cowie said she was surprised that the rate of undiagnosed diabetes did not change significantly between the two studies.

“We knew there would be an increase in diabetes diagnoses but we hoped to find a decrease in the rate of undiagnosed diabetes,” she told Endocrine Today. “We expected, given the abundance of public health messages about diabetes in recent years, there would be a decrease in undiagnosed diabetes. Unfortunately, we did not see this counterbalance.”

Improved screening needed

Cowie said she encourages improvements and increases in screening patients for diabetes. “We have to get the message out to both health care providers and patients,” she said. “Health care providers should be conducting diabetes screening in any patients who are overweight or obese, sedentary, older, members of an at-risk minority group, and those who have a family history of diabetes.”

Cowie added that early diagnosis of diabetes is of the utmost importance to reduce the risk of long-term complications. “The complications of diabetes are the real problem,” she said. “So, the sooner the patient is diagnosed and treated, the better they will be.”

The study also found that diabetes disproportionately affects blacks and Mexican-Americans. Cowie said more information is needed about why these populations are at a higher risk. She reiterated the hypothesis that there may be genetic factors, as well as obesity, that play a role in the increased risk of diabetes in some minority populations.

The study results showed that older patients are also at an increased risk for diabetes. The rate of diabetes among people over the age of 65 was 22%. In comparison, it was 12.1% for people under the age of 60. – by Jay Lewis

For more information:

Cowie CC, Rust KF, Byrd-Holt DD, et al. Prevalence of diabetes and impaired fasting glucose in adults in the U.S. population: National Health and Nutrition Examination Survey 1999-2002. Diabetes Care. 2006;29:1263-1268.