Diabetes and Vascular Disease

The incidence of diabetes is on the rise; most of this increase is accounted for by type 2 diabetes and is secondary to the growing prevalence of obesity. Most of the late complications of both type 1 and type 2 diabetes are secondary to microvascular and macrovascular complications. Microvascular complications include retinopathy, neuropathy, and nephropathy. Nephropathy is strongly linked to the complications of macrovascular disease, which include cardiovascular, cerebrovascular, and peripheral vascular disease. Hence, once microalbuminuria (an early marker of nephropathy) is present, the patient is at a greater risk of cardiovascular disease and other microvascular complications, including retinopathy. A number of cellular mechanisms are altered secondary to hyperglycemia, and recently, a common pathway linking these mechanisms has been proposed, ultimately leading to oxidative damage and thus end-organ or tissue damage. Due to the increased risk of vascular complications, many diabetic patients undergo surgical procedures, including revascularization and bypass. Recent studies have highlighted the importance of strict glycemic control during the perioperative and postoperative period, even in the nondiabetic patient. The results of these studies have shown a decrease in morbidity, mortality, and hospital stay with strict glycemic control. Glycemic control has been directly linked to decreased microvascular complications. Macrovascular disease, however, has not been clearly linked to glucose levels alone, and although it certainly plays a role, other components of the metabolic syndrome, including blood pressure and lipid status, are equally important.