Of the 1,704 overweight patients in the study, 342 were randomized to intensive therapy with metformin.
Patients in whom glycemic goals were not met with intensive monotherapy received combination therapy. In sulfonylurea-treated patients either metformin or insulin was added and in metformin-treated patients a sulfonylurea was added; if the glycemic goal was still not met, insulin was substituted for the sulfonylurea.
The aggregate endpoints for metformin-treated patients were:
any diabetes-related clinical endpoint (sudden death, death from hyperglycemia or hypoglycemia, fatal or nonfatal MI, angina, heart failure, stroke, renal failure, amputation of at least one digit, vitreous hemorrhage, retinopathy requiring photocoagulation, blindness in an eye, or cataract extraction) diabetes-related mortality (death from MI, stroke, PVD, renal disease, hyperglycemia or hypoglycemia, or sudden death)
all-cause mortality.
To determine the effect of intensive treatment on vascular disease, secondary outcomes analysis included:
MI (both fatal and nonfatal and sudden death)
stroke (both fatal and nonfatal) amputation of at least one digit or death from PVD microvascular complications (retinopathy necessitating photocoagulation, vitreous hemorrhage, fatal and nonfatal renal failure).
Intensive metformin therapy significantly reduced any diabetes-related endpoint by 32% (P=0.0023); diabetes-related mortality by 42% (P=0.017); all-cause mortality by 36% (P=0.011); and MI by 39% (P=0.01).

UK Prospective Diabetes Study (UKPDS) Group. Lancet. 1998;352:854-865.
American Diabetes Association. Diabetes Care. 1999;22(suppl 1):S27-S31.