Q: Can people with prediabetes take the drug metformin to prevent or at least delay the onset of full-blown diabetes?
A: Yes, but it is recommended only if intensive lifestyle changes haven’t helped, according to 2016 guidelines from the American Diabetes Association (ADA).
People with prediabetes (sometimes called impaired glucose tolerance) have fasting blood glucose levels between 100 and 125 (normal is below 100, while above 125 is considered diabetes). It’s estimated that more than one-third of American adults have prediabetes.
Metformin is usually the initial drug used to treat type 2 diabetes. The FDA has not approved it for prediabetes, so such use is considered “off label.”
The ADA cited research showing that an intensive diet-and-physical-activity counseling program that promotes weight loss is most effective for the prevention of diabetes in people with prediabetes. The important Diabetes Prevention Program study from 2002, for instance, found that such a program reduced the rate of progression of prediabetes to diabetes by 60 percent over three years; metformin was only half as effective overall. But among participants under 60 who were very obese, the drug was as effective as the counseling program.
It is much better to prevent diabetes by improving your diet and exercise habits than by taking a drug, presumably for the rest of your life. Such lifestyle changes and resulting weight loss will have a host of other health benefits as well. But for obese people who have repeatedly failed with the lifestyle program, medication may be an option.
Also see Stopping Diabetes Before It Starts for more about theDiabetes Prevention Program.