Metformin is prescribed not only for people with diabetes, but also for people with prediabetes. For them it’s used as a way of preventing, not treating, the disease. Previously, it’s been shown that metformin can delay the onset of Type 2 diabetes for 3 to 10 years. This new research, however, reveals that the delay goes on for 15 years. According to study author David M. Nathan, MD, “That’s a pretty powerful effect.”
That wasn’t all the good news. The study began with 3,234 people over 25 who were considered at risk for Type 2 diabetes. They were participants in what is known as the Diabetes Prevention Program (DPP) and were randomly assigned to one of three groups — one group that received intensive lifestyle modification, one that received metformin, and one that received a placebo (inactive treatment). The follow-up lasted 15 years, and at the end the incidence of diabetes development was 17 percent lower among the metformin group than the placebo group. And it didn’t matter how the presence of diabetes was determined. According to Dr. Nathan, “Whichever method you use, you get this persistent durable benefit with metformin. To me, that’s the most important message.”
Another impressive finding was that the benefits of metformin were particularly strong among those with higher blood sugar at the study’s onset and among women with a history of gestational diabetes, a temporary form of the disease that occurs during pregnancy. Dr. Nathan added, however, “That doesn’t mean that others with prediabetes criteria don’t benefit, but that some subgroups have even more benefit.”
One of the strengths of metformin is that it’s been around so long. Although it’s been used in the United States only since the 1990s, its discovery dates to the 1920s. This means we have plenty of experience with it and a lot of time to evaluate its safety and effectiveness. It also means that the drug is available in a generic form, which makes it quite inexpensive. As Dr. Nathan explained, “….it may be just what the drug companies hate — a drug that costs 10 cents a pill.”
A freelance writer and editor based in the Chicago area, Gustaitis has a degree in journalism from Columbia University.