Lowering hemoglobin A1c level to less than 6.0% in people with type 2 diabetes may reduce major adverse cardiovascular events: a Bayesian’s narrative

Abstract

Whether lowering the hemoglobin A1c to <6.0% in patients with type 2 diabetes can reduce the risk of cardiovascular disease (CVD) remains under debate. The ACCORDION and the VADT studies both found reductions in the primary CVD composite associated with intensive glycemic control, though the difference is not statistically significant. However, the lack of significance is often overinterpreted as non-effective: a p-value >.05 only implies that the study “failed to reject” the null hypothesis (i.e. lowering the A1c level to <6.0% results in no CVD benefit), which is different from concluding the null hypothesis being true. In this study, we used Bayesian analysis to reanalyze results from the ACCORDION and VADT-15 trials. Our results suggest achieving an A1c goal of <6.0% as compared to moderate control could result in a moderate risk reduction in MACE.