The effect of HbA1c variability on the efficacy of intensive blood pressure control in patients with type 2 diabetes

AimsThe efficacy of intensive blood pressure (BP) control remains controversial, and the variability of HbA1c was a risk factor for macrovascular events in patients with type 2 diabetes. We investigated whether the HbA1c variability modifies the efficacy of intensive BP control. MethodsData from the Action to Control Cardiovascular Risk in Diabetes Blood Pressure (ACCORD-BP) trial was utilized. K-means clustering was used to cluster patients into three groups based on the HbA1c variability score and baseline HbA1c values. Cox proportional hazard models and generalized linear models were used to measure the subgroup differences in intensive BP control treatment effects. The primary outcome was a composite of nonfatal myocardial infarction (MI), stroke, or death from cardiovascular causes. ResultsIn patients with low HbA1c variability rather than medium or high HbA1c variability, intensive BP control reduced the risk of the primary outcome on a relative scale (HR 0.60, 95%CI 0.40-0.90, p interaction was 0.03), non-fatal MI (HR 0.61, 95% CI 0.37-1.00, p interaction was 0.04) and stroke (HR 0.19, 95%CI 0.05-0.64, p interaction was 0.02) or absolute scale. Regardless of the variability group, intensive BP control did not reduce the risk of cardiovascular or all-cause mortality (p interaction >0.05) both on relative and absolute risk scales. ConclusionHbA1c variability had effect on the efficacy of intensive BP control and intensive BP control brought a significant macrovascular benefit in patients with type 2 diabetes and low HbA1c variability.