Prevention of Type 2 diabetes: fact or fiction?

The growing prevalence of Type 2 diabetes with its high morbidity and excess mortality is imposing a heavy burden on healthcare systems. Because of the magnitude of the problem, obviating diabetes has been a long-standing dream. In the last decade, a number of intervention strategies have been shown to be effective for the prevention of diabetes in high-risk populations with prediabetes. Seven studies have now confirmed that lifestyle modifications, including weight-reducing diets and exercise programs, are very effective in precluding or delaying Type 2 diabetes in high-risk populations with impaired glucose tolerance (IGT). Two major trials are the Diabetes Prevention Study (n = 522) from Finland and the Diabetes Prevention Program (n = 3234) from the US. Both studies have shown that intensive lifestyle intervention could reduce the progression of IGT to diabetes by 58%. Furthermore, four currently-available drugs have been established as being effective in preventing diabetes in subjects with prediabetes. The Diabetes Prevention Program revealed that metformin 850 mg b.i.d. reduced the risk of diabetes by 31%. The STOP-NIDDM (Study To Prevent Non-Insulin-Dependent Diabetes Mellitus) trial (n = 1429) showed that acarbose 100 mg t.i.d. with meals decreased the incidence of diabetes by 36% when the diagnosis was based on 2 oral glucose tolerance tests. The XENDOS (Xenical in the Prevention of Diabetes in Obese Subjects) study examined the use of orlistat, an antiobesity drug, as an adjunct to an intensive lifestyle modification program in obese non-diabetic subjects. Orlistat treatment resulted in a 37% decline in the development of diabetes. More recently, the DREAM (Diabetes Reduction Assessment with Ramipril and Rosiglitazone Medication) study (n = 5269) demonstrated that rosiglitazone at 8 mg once/day in subjects with prediabetes (IGT and/or impaired fasting glucose) was effective in reducing the risk of diabetes by 60%. It can be concluded that Type 2 diabetes can be prevented or delayed through lifestyle modifications and/or pharmacologic interventions. This is a fact.