This is a randomized, parallel group clinical trial in insulin-treated patients with diabetes mellitus who have been scheduled for elective vascular surgery. We will randomize 46 participants diabetes mellitus: insulin-treated with HbA1c 7.5% or treated with oral agents with an elevated HbA1c who are scheduled for vascular surgery and in whom a 6 week pre-operative delay poses no substantial medical risks, as determined by the staff surgeon. We will exclude individuals with markedly elevated HbA1c or blood pressure; those with recently manifest cardiovascular disease, and those unable to attend regularly scheduled follow-up visits during the pre-operative period.