Pre-diabetes. The term can make a patient exam room quiet and has the potential for emotional responses. Some patients may show disbelief, others anger, or sadness. The term is one wrought with concern and a harbinger for the future. Unfortunately, the term has grown increasingly common in primary care.

I will be the first to admit, I am not partial to the term. I like to believe in patients and empower them to improve their lives. The term implies a certain unstoppable progression to diabetes, as if it were inevitable. Instead, I have chosen to believe in patients and use “impaired fasting glucose” or “glucose intolerance” instead.

As more patients come back to the office for spring and summer visits after a long, cold winter where it is much easier to sit on the couch than it is to exercise, I see more and more fasting glucoses creeping up into the low 100s.

The definition of glucose intolerance is a fasting blood sugar between 100 and 125 mg/dL or a hemoglobin A1C between 5.7 and 6.4%. Unfortunately, it is estimated that one in three adults may have impaired fasting glucose (McGraw and Lee, 2016). Up to 86 million Americans are afflicted with the disease, but of this, only about 11% are aware.

This also assesses the importance of screenings and regular visits to the family medicine office for routine physicals. Many Americans have no idea that they are at risk for diabetes. A high incidence is found in Native Americans, Hispanics, African Americans, and the obese.

Of those who are diagnosed with impaired fasting glucose this year, about 15 to 30% of these patients will develop diabetes in the next five years. Not only is it important to monitor routine lab work to assess progression of elevations in sugars, one should motivate patients to avoid developing diabetes.

The risk factors for impaired fasting glucose are somewhat obvious. A BMI > 30, sedentary lifestyle, poor diet, obesity, metabolic syndrome, glucocorticoid use, anti-psychotic medications, and previous history of gestational diabetes. General prevention includes eating a diet rich in whole grains, proteins, fruits, vegetables and avoiding refined carbohydrates.

Screening for impaired fasting glucose involves a fasting glucose level. Patients with BMI > 25, age >35, obesity, family history of diabetes, sedentary lifestyle, hypertension, family history of cardiac disease, PCOS, or evidence of acanthosis nigricans should be screened.

The United States Preventive Task Force makes a Grade B recommendation to screen adults over 40 with a fasting sugar for patients who are categorized as overweight or obese as part of a cardiac disease screening. With the rise of obesity, many patients need screening much sooner than this, or run the risk of having diabetes for years without knowing.

Many Americans’ employers are starting to do more wellness checks for sugar. In my experience, I have at least one to two patients per week who may come in with labs from a screening company, indicating that their glucose or hemoglobin A1C was elevated.

It is excellent that employers are doing these, but the clinician should assure the patient was fasting adequately for 12 hours prior to determining a sugar to be abnormal.

By definition, many patients with impaired fasting glucose do not have any symptoms at the time of diagnosis. Comorbid hypertension, obesity, or a lack of physical activity in the patient history can make the clinician suspect the possibility. Depending on sugar level, some patients may complain of polyuria, polydipsia, blurry vision, or weight loss.

Once the diagnosis is made via lab draw, other endocrine disease should be considered, such as acromegaly, hemochromatosis, hyperthyroidism, Cushing syndrome. Drug induced hyperglycemia can come from prednisone, beta blockers, protease inhibitors, and atypical antipsychotics.

Once a diagnosis is made, the treatment is mostly behavioral. Physical activity is paramount as well as weight loss. Patients should be counseled to get at least 150 minutes of exercise per week at a moderate level or 90 minutes at a vigorous level. Resistance exercise via weight lifting is helpful as well.

Along with exercise, many patients need dietary counseling. Patients should be counseled on a lower calorie, lower carbohydrate diet. Diets higher in fiber and protein can help slow progression of disease. A diet rich in whole grains, nuts, seeds, fruits and vegetables is reasonable.

Patients should be counseled to avoid soda and other beverages with added sugars, which are quickly used up by the body and offer almost no nutritional value. A visit with a medical nutritionist or dietician, if covered by insurance, can help promote healthy habits.

For patients with higher A1Cs, a reasonable suggestion is the use of metformin. Metformin has been shown to reduce the incidence of progression to type 2 diabetes, is well tolerated, and is cheap. Some patients, in whom lifestyle changes are not beneficial, may benefit from the drug.

In my practice, if a patient has an abnormal glucose level on their routine lab work, I bring them in for an appointment. I have a discussion with them about lifestyle, exercise regimens and diet. My goal as a provider is always to empower positive changes in patients. Once the counseling and lifestyle are discussed, I ask the patient to repeat lab work in 4 to 6 months, hoping to see a reduction in their sugar.

Impaired fasting glucose, as defined as a blood sugar of between 100 and 125 or hemoglobin A1C of 5.7 to 6.4, is a growing problem in the United States. Many patients unfortunately progress to type 2 diabetes, but not all. Diet, exercise, and sometimes the use of metformin is the mainstay of therapy.


McGraw, K. and Lee, J. (2016). Glucose Intolerance. The 5 Minute Clinical Consult.

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