The clinical trial ended one year earlier than planned because the results were so clear:
The lifestyle intervention group reduced their risk of developing diabetes by 58 percent.
This powerful reduction in risk of diabetes was found in all subgroups, including men and women, the ethnic groups that made up 45 percent of participants, women with a history of gestational diabetes, and people age 60 and older.
In fact, lifestyle changes worked particularly well for participants aged 60 and older—who as a group have nearly 20 percent prevalence of diabetes—reduced their risk of developing diabetes by 71 percent.
Participants who took metformin reduced their risk of developing diabetes by 31 percent.
Metformin was effective for both men and women, and was more effective in younger, heavier people—those 25 to 40 years old with a BMI of 36 (about 50 to 80 pounds overweight).
Reference
Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002, Vol.346, No. 6.