Patients with Metabolic Syndrome have an increased risk of developing Diabetes compared to those with impaired glucose tolerance alone. Treatment with acarbose has been shown to reduce the risk of developing Diabetes from 18.7% to 13.5% in patients with Metabolic Syndrome. This provides a relative risk reduction of 27% per year. The number needed to treat to prevent diabetes over 3.3 years was 5.8 in those patients with Metabolic Syndrome. In patients without Metabolic Syndrome, the intervention was less successful with a number needed to treat of 16.5.