Approximately 84 million American adults — more than 1 out of 3 — have prediabetes, with an increased risk of developing Type 2 diabetes, heart disease, and stroke, and 90 percent don’t realize they are at risk.

Prediabetes, which is not a disease itself, is characterized by high blood sugar, almost to the point of being diagnosed as diabetes. People with prediabetes have a greater risk of vascular problems, kidney disease, and nerve and retinal damage.

The problem with prediabetes is that there are no clear symptoms, but some of the risk factors include being overweight, age (45 years or older), parents or siblings with Type 2 diabetes, physical inactivity (exercise less than three times a week), gestational diabetes and polycystic ovary syndrome.

The detection and treatment of prediabetes can delay the onset of diabetes and presents an important diabetes prevention strategy. Prediabetes is diagnosed by labs, specifically an elevated fasting glucose of 100-125 mg/dL or hemoglobin A1c (HbA1c) of 5.7-6.4 percent.

Diabetes is diagnosed based on labs above those thresholds, fasting glucose greater than or equal to 126 mg/dL or HbA1c of greater than or equal to 6.5 percent. Once detected, prediabetes should be acknowledged with a treatment plan to prevent or slow the transition to diabetes.

It is unclear, however, whether primary care physicians (PCPs) diagnose prediabetes and adjust the treatment plan in light of HbA1c results. In a previous study, there were no significant differences in receiving treatments based on HbA1c level.

Of patients with an HbA1c level between 5.7 percent and 5.9 percent, 22.6 percent received treatment for prediabetes, compared with 23.5 percent of patients with an HbA1c level between 6 and 6.4 percent.

A study in the Journal of the American Board of Family Medicine does not explain why physicians did not record a prediabetes diagnosis and offer patients effective interventions to delay the onset of diabetes. Potential explanations include lack of awareness of the potential effect of interventions in reducing diabetes risk, lack of access to providers of dietary and exercise advice, and therapeutic inertia.

In a recent study to better understand why so many with prediabetes go undiagnosed, Eva Tseng and a research team created a survey to test awareness of expert prediabetes guidelines and beliefs regarding prediabetes management.

At an annual retreat and medical update held for mid-Atlantic region PCPs, Tseng and Johns Hopkins researchers invited all 156 PCPs who attended the meeting to participate in the on-site survey. To evaluate attitudes and beliefs regarding prediabetes, the survey asked providers to rate, on a five-point scale (strongly agree to strongly disagree), whether they believe it is important to identify prediabetes and whether they believe that lifestyle modification and metformin can reduce the risk of progression to diabetes.

A similar scale was used to evaluate what providers perceive as patient barriers to lifestyle modification and the use of metformin.

The vast majority of the 140 doctors who responded could not identify all 11 risk factors that qualify patients for prediabetes screening. The survey also revealed that nearly one-third of the PCPs were unfamiliar with the American Diabetes Association's (ADA) guidelines for prediabetes.

Six percent of PCPs correctly identified all of the risk factors that should prompt prediabetes screening. Only 17 percent of PCPs correctly identified the laboratory parameters for diagnosing prediabetes based on both fasting glucose and HbA1c.

Nearly 90 percent of PCPs reported close follow-up (within 6 months) of patients with prediabetes. Few PCPs (11 percent) selected referral to a behavioral weight loss program as the recommended initial management approach to prediabetes.

PCPs agreed that patient-related factors are important barriers to lifestyle change and metformin use. Provider characteristics were generally not associated with knowledge, management, attitudes and beliefs about prediabetes.

According to the study researchers, addressing gaps in knowledge and using behavioral weight loss programs in prediabetes are two essential areas where PCPs could take a lead in curbing the diabetes epidemic.