The Influence of baseline glycemic status on the effects of intensive blood pressure lowering: Results from the STEP randomized trial

Abstract

Background: Intensive systolic blood pressure (SBP) lowering showed cardiovascular benefits in the Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) trial. We investigated whether baseline glycemic status influences the effects of intensive SBP lowering on cardiovascular outcomes.

Methods: In this post hoc analysis of the STEP trial, participants were randomly assigned to receive intensive (110 to <130 mmHg) or standard SBP treatment (130 to <150 mmHg) and categorized by baseline glycemic status into three subgroups: normoglycemia, prediabetes, and diabetes. The primary outcome was a composite of stroke, acute coronary syndrome, acute decompensated heart failure, coronary revascularization, atrial fibrillation, or death from cardiovascular causes. A competing risk proportional hazards regression model was used in the analysis.

Results: Of the 8,318 participants, 3,275, 2,769, and 2,274 had normoglycemia, prediabetes, and diabetes, respectively. Over a median follow-up of 3.33 years, intensive SBP lowering significantly reduced the risk of the primary outcome (adjusted hazard ratio 0.73, 95% confidence interval [CI] 0.59-0.91). The adjusted hazard ratios for the primary outcome in the normoglycemia, prediabetes, and diabetes subgroups were 0.72 (95% CI 0.49-1.04), 0.69 (95% CI 0.46-1.02), and 0.80 (95% CI 0.56-1.15), respectively. The intensive SBP lowering strategy resulted in similar effects among participants in the three subgroups (all interaction P >0.05). The sensitivity analyses showed consistent results with the main analysis.

Conclusion: The effects of intensive SBP lowering on cardiovascular outcomes were consistent among participants with normoglycemia, prediabetes, and diabetes.

Keywords: Blood pressure; Diabetes; Hypertension; Intensive SBP lowering.