CSP #465 is a prospective, 2-arm, randomized controlled trial to determine whether glycemic control, achieved through intensification of treatment, is effective in preventing clinical macrovascular complications in patients with type 2 DM who are no longer responsive to oral agents alone. The study consists of a two-year accrual period and five years of follow-up (7 years total) of 1700 patients across 20 centers. We have powered the study to detect a 25% reduction in the primary event rate. Additional study goals are to determine whether the expenditures, discomfort, and adverse effects associated with intensive intervention are justified in terms of their clinical benefits, considering both macrovascular and microvascular complications.