The influence of baseline diastolic blood pressure on the effects of intensive blood pressure lowering on cardiovascular outcomes and all-cause mortality in type 2 diabetes mellitus
Research Design and Methods: The Action to Control Cardiovascular Risk in Diabetes Blood Pressure trial (ACCORD BP),a 2X2 factorial randomized controlled trial, examined effects of SBP (<120 vs. <140 mmHg) and glycemic (HbA1C < 6% vs. 7.0–7.9% (<42 vs 53-63 mmol/mol)) control on cardiovascular events in T2DM (N=4731). We examined whether effects of SBP control on cardiovascular composite was modified by baseline DBP and glycemic control.
Results: Intensive SBP lowering decreased the risk of the cardiovascular composite (HR 0.76, 95% CI 0.59 to 0.98) in the standard glycemic arm but not in the intensive glycemic arm (HR=1.06, 95% CI 0.81 to 1.40). Spline regression models relating the effects of the intervention on the cardiovascular composite across the range of baseline DBP did not show evidence of effect modification by low baseline DBP for the cardiovascular composite in the standard or intensive glycemic arms. The relation between the effect of the intensive SBP intervention and baseline DBP was similar between glycemic arms for the cardiovascular composite (3-way interaction p-value = 0.83).
Conclusions: in persons with T2DM, intensive SBP lowering decreased the risk of cardiovascular composite endpoint irrespective of baseline DBP in the setting of standard glycemic control. Hence, low baseline DBP should not be an impediment to intensive SBP lowering in T2DM patients treated with guidelines recommended standard glycemic control.