For years, the jargon-filled names given to this condition — impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) — may have made the task of taking it seriously more difficult. But in 2002, the American Diabetes Association (ADA), along with the U.S. Department of Health and Human Services, inaugurated the term “prediabetes” to convey the likely result of not making diet or lifestyle changes in response to this diagnosis. In 2003, the threshold for prediabetes was lowered from a fasting glucose level of 110 mg/dl to one of 100 mg/dl.
Then, in 2008, the American Diabetes Association (ADA) began recommending the drug metformin for some cases of prediabetes — specifically, for people under age 60 with a very high risk of developing diabetes, for people who are very obese (with a body-mass index, or BMI, of 35 or higher), and for women with a history of gestational diabetes. The ADA also said that health-care professionals could consider metformin for anyone with prediabetes or an HbA1c level (a measure of long-term blood glucose control) between 5.7% and 6.4%.
But according to a recent study, metformin is still rarely prescribed for prediabetes. The study, published in April in the journal Annals of Internal Medicine, found that only 3.7% of people with prediabetes were prescribed metformin over a three-year period, based on data from a large national sample of adults ages 19 to 58. According to a Medscape article on the study, 7.8% of people with prediabetes with a BMI of 35 or higher or a history of gestational diabetes were prescribed metformin — still a very low rate for the highest-risk groups, in which evidence for the benefits of metformin is strongest. It appears that most doctors simply aren’t following the ADA’s guidelines or aren’t aware of them, as they relate to prediabetes.
As we noted here at Diabetes Flashpoints in a 2011 post, both metformin and lifestyle intervention programs have been found to be effective at slowing the progression of prediabetes to Type 2 diabetes — with lifestyle intervention found to be more effective but more expensive. While there is debate about when and whether it’s best to prescribe metformin or a lifestyle program for prediabetes, it’s unlikely that more than a handful of the participants in the recent study were participating in lifestyle programs, instead of or in addition to taking metformin.
What’s your view — why do you think more doctors don’t prescribe metformin for prediabetes? Do the ADA’s recommendations reflect a willingness to prescribe drugs without first giving lifestyle interventions a chance? Given the choice, would you rather take a drug or participate in a lifestyle program for prediabetes? Do you think people who are prescribed a drug, like metformin, are more or less likely to make lifestyle changes that could help their prediabetes? Leave a comment below!