4. Subjects must meet the criteria for impaired glucose tolerance (FPG concentration <126 mg/dl and a two hour plasma glucose value during the oral glucose tolerance test [OGTT] ≥140 but <200 mg/dl) or type 2 diabetes mellitus (FPG concentration ≥ 126 mg/dl or a two hour plasma glucose value during the OGTT ≥200 mg/dl) (62). Subjects with a FPG greater than 260 mg/dl will be excluded from the study.