Diabetes mellitus is a risk factor for coronary heart disease, ischemic stroke, and peripheral arterial occlusion (macrovascular disease), as well as chronic kidney disease, neuropathy, and retinopathy (microvascular disease). Antihyperglycemic treatments reduce the risk of microvascular conditions, but their effect on macrovascular events is uncertain (1, 2). Years ago, the University Group Diabetes Program suggested that sulfonylureas and phenformin might increase the risk of major adverse cardiovascular events (3). After similar concerns were raised about two PPAR-γ agonists (4, 5), the FDA convened an Advisory Committee in 2008 to discuss how to evaluate the cardiovascular safety of diabetes drugs (6-8).