One in three Americans has prediabetes, which greatly increases the risk of developing diabetes. So you may be at risk yourself.

It’s easy for your doctor to screen you in the office with a blood glucose test. But what if your doctor doesn’t know what to look for to see if you need testing?

Background: More than 90% of people with prediabetes don’t know that they have the condition that sets them up for progression to full-blown diabetes and heart disease. If prediabetes is identified and treated properly, primarily through lifestyle changes but also in some cases medication, diabetes can often be prevented entirely…or delayed for many years. Since there are often no symptoms of prediabetes, however, it’s important that primary care providers know how to spot the condition.

Study: Researchers from Johns Hopkins conducted a survey of 140 primary care providers (including physicians, nurse practitioners and physician assistants) who work for practices affiliated with a single large academic medical center. Although the study was limited to just those connected to just one medical center, the practices were both urban and suburban, and the population treated by these primary care providers was racially and economically diverse, representing a cross section of the American population.

The survey was designed to assess the primary care providers’ knowledge of the risk factors that should prompt screening for prediabetes, laboratory criteria for diagnosis and appropriate therapy for people who get a diagnosis. The risk factors apply to anyone who is overweight or obese—age (45 and up), high blood pressure, abnormal cholesterol levels, heart disease, a family history of diabetes, being sedentary, a history of gestational diabetes, smoking and ethnicity/race (African-American, Asian, Hispanic). If an overweight or obese person has any of those risk factors, he or she should be screened.

Results: Only 6% of survey respondents were able to correctly identify all these risk factors that should prompt screening. While most of the respondents knew that family history of diabetes and high blood pressure were warning signs, few realized that being of Asian or Hispanic race was a factor. The ignorance extended to diagnosis—only 17% of respondents were able to correctly identify the laboratory value cut-off limits for diagnosing prediabetes.

Surprising finding: Almost all (99%) of those who responded to the survey knew that weight-loss counseling programs work and reduce risk of developing full-blown diabetes. But…just 12% of respondents actually refer their patients to such programs as a first step in their treatment plans.

Bottom line: Your primary care provider may have knowledge gaps when it comes to prediabetes, so be proactive. The American Diabetes Association has an online diabetes-risk self-test. To learn more about screening and prevention, see Bottom Line’s article, “Beat Prediabetes with These Simple Steps.”