Differences in glycemic control between the treatment arms in cardiovascular outcome trials of type 2 diabetes medications do not explain cardiovascular benefits

Hyperglycemia is an undisputed epidemiological risk factor for microvascular complications in both type 1 and type 2 diabetes, integral in their causal pathways. Importantly, interventions that reduce the hyperglycemic burden in patients with either type of diabetes reduce the risk of microvascular complications (e.g., retinopathy, nephropathy, neuropathy). Hence, for microvascular risk, hyperglycemia is a proven risk factor and a proven treatment target, as reflected by treatment recommendations and guidelines across most scientific societies world-wide. However, although reducing the hyperglycemic burden to reduce microvascular risk remains a cornerstone of care for patients with type 2 diabetes, this therapeutic imperative does not apply to cardiovascular risk mitigation. This latter aspect is important in the context of interpreting therapeutic impact of treating hyperglycemia on risk for macrovascular complications in patients with type 2 diabetes. This letter, in response to a previous paper, discuss how modest differential glucose control contribute little if anything to the results observed of contemporary cardiovascular outcome trials in type 2 diabetes.