Effect of strict glycemic control in patients with diabetes mellitus on frequency of macrovascular events.

Despite a better understanding of cardiovascular risk factors and attempts at optimal management, diabetes-related macrovascular events remain a significant cause of morbidity and mortality in the United States and worldwide. The trials to date have validated strict glycemic control as a method to achieve sustained reductions in the rate of nephropathy, neuropathy, and retinopathy due to diabetes. For these microvascular complications, the closer hemoglobin A1c is to normal levels, the better the outcome. Although reducing hemoglobin A1c levels to 7% has been shown to reduce macrovascular events, demonstrating an additional reduction in macrovascular events with tighter glycemic control has been more difficult to achieve. A careful review of recent trials, however, has demonstrated that treatment early in the disease course and the ability to safely maintain lower hemoglobin A1c levels might be critical factors in further reducing macrovascular events. In conclusion, with the introduction of novel antidiabetic agents, future trials using these drugs might be able to definitively establish the safety and efficacy of reducing cardiovascular events with stringent glycemic control; however, the current evidence is inconsistent.