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What are the signs of prediabetes? How can you help your patients?


Approximately 25% of Canadian adults have prediabetes (meaning almost one in four adults who come in to your pharmacy!), and approximately half of these individuals will develop diabetes.

By Shelley Diamond, BScPhm

Illustration by Martin Bregman

The Canadian Diabetes Association’s 2013 Clinical Practice Guidelines use the term ‘prediabetes’ for individuals with impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or a glycated hemoglobin (A1C) of 6.0 to 6.4%. Approximately 25% of Canadian adults have prediabetes (meaning almost one in four adults who come in to your pharmacy!), and approximately half of these individuals will develop diabetes.

A specific diagnosis of prediabetes is made based on any one of the following:

Category of prediabetes Test and result
IFG FPG (fasting plasma glucose) of 6.1-6.9 mmoL/L
IGT 2-hour plasma glucose 7.8-11.0 mmol/L following a 75 g oral glucose tolerance test
Prediabetes A1C 6.1-6.4%

If someone has both IFG and an A1C of 6.1-6.4%, it is predictive of 100% progression to type 2 diabetes within five years.

Can prediabetes be reversed?

For some patients, ‘yes’! Several trials have examined the impact of lifestyle intervention with/without medications on the prevention of diabetes in people with prediabetes. These studies have shown that the incidence of diabetes can be reduced by 25-72%, however most people continued to have prediabetes. However, 20-50% did not progress to diabetes, and also reverted to normal glucose levels. Those who tended to reach normal glycemic status were younger with better beta-cell function, and/or weight loss and intensive lifestyle intervention.

How can you support your patients?

First help identify those at risk for diabetes and/or prediabetes and recommend screening at least every three years. If you are using A1C point-of-care testing, and you find patients with an A1C at or above 6.1%, refer them to their physician. A repeat A1C is required to confirm the diagnosis of prediabetes.

Provide education on lifestyle interventions. Regular physical activity (at least 150 minutes/week) and moderate weight loss (5-10%) in overweight patients can prevent diabetes in about one in seven patients with prediabetes when maintained for three years. Three large studies of lifestyle intervention have shown that there is sustained reduction for seven, 10 or 20 years.

Consider flagging patients using lifestyle management strategies for followup at three to six months if their blood glucose values have not returned to normal, to discuss initiation of metformin. Metformin has been shown to prevent diabetes in about one in 14 patients over three years. It also has the strongest evidence for its prevention of diabetes, and has long-term safety data, making it the drug of choice. The starting dose is 500mg daily, but this can be increased as high as 850mg twice daily if in six months, the A1C is still ≥6%. Another option is acarbose for those unable to take metformin.

Many people with prediabetes also have obesity, hypertension and dyslipidemia, with increased risk for cardiovascular events. Therefore it’s important to treat these risk factors as well as others (e.g. smoking). The goals are the same for people with prediabetes as for anyone without diabetes.

People with prediabetes ‘fall through the cracks’ in terms of receiving education and support. Since the same principles apply, much of the education you provide to your patients with diabetes also applies to those with prediabetes. In fact, helping people with prediabetes revert to normoglycemia with early and more aggressive glucose lowering, especially in those at highest risk, may mean being able to avoid micro- and macro-vascular disease. The exact strategy (lifestyle modification vs medication) is less important than the early initiation. Consider making a difference for your patients now!