This study also aims to assess the efficacy and safety of glibenclamide plus rosiglitazone versus glibenclamide plus placebo therapy in Korean patients with type 2 diabetes. In addition, a previous study has shown that in Korean patients, early-phase insulin secretory defect may be the initial abnormality in the development of type 2 diabetes mellitus. This study aims to show that rosiglitazone treatment in Korean patients, regardless of their early phase insulin secretory ability, is just as efficacious and safe.