The results of a randomized three-year clinical trial of 3,234 adults (USA), named the Diabetes Prevention Program (DPP), supports the premise that lifestyle changes can prevent or delay the onset of type 2 diabetes among high-risk adults, including people with IGT and other risk factors. Lifestyle interventions include diet and appropriate physical activity such as walking for 2 ½ hours each week. The Diabetes Prevention Program showed a reduction in the incidence of diabetes by 58% with a systematic and intensive lifestyle intervention (150 minutes/week), which demonstrates that in a three-year period an effect is seen of one case of diabetes prevented for every seven persons treated.5-7
As medications have also been shown to prevent diabetes in some population groups, the second of the three random groups in the DPP studied the effect of metformin (Glucophage), a biguanide class of oral anti-diabetic drugs, in the prevention/delay of type 2 diabetes. People treated with metformin showed a reduction in their risk of developing diabetes by 31% over three years. This protocol was most effective among younger, heavier people (those 25-40 years of age at 50 to 80 pounds overweight) and less effective among older people and people who were not as overweight.5-7 In a similar study, the STOP-NIDDM Trial, treatment of people with IGT with the drug acarbose (Precose) reduced the risk of developing diabetes by 25% over three years.5,8,9
In addition to preventing progression from IGT to diabetes, both lifestyle changes and medication have also been shown to increase the probability of reverting from IGT to normal glucose tolerance.5-9 Bariatric surgery may be part of a comprehensive approach to diabetic prevention and/or management. Risks, costs and benefits for various patient populations are currently under study.54 However, there are currently no known methods to prevent type 1 diabetes.