Body Mass Index, Intensive Blood Pressure Management, and Cardiovascular Events in the SPRINT Trial

Background It is unclear whether intensive blood pressure management is well-tolerated and affects risk uniformly across the body mass index (BMI) spectrum. Methods The randomized, controlled Systolic Blood Pressure Intervention Trial (SPRINT) included 9361 individuals ≥50 years of age at high cardiovascular risk, without diabetes mellitus, with systolic blood pressure between 130 and 180 mmHg. Participants were randomized to intensive vs standard antihypertensive treatment and evaluated for the primary composite efficacy endpoint of acute coronary syndromes, stroke, heart failure, or cardiovascular death. The primary safety endpoint was serious adverse events. We used restricted cubic splines to determine the relationship between BMI, response to intensive blood pressure lowering, and clinical outcomes in SPRINT. Results Body mass index could be calculated for 9284 (99.2%) individuals. Mean BMI was similar between the 2 treatment groups (intensive group 29.9±5.8 kg/m2 vs standard group 29.8± 5.7 kg/m2; P = 0.39). Median follow-up was 3.3 years (range 0-4.8 years). Body mass index had a significant, J-shaped association with risk of all-cause mortality, stroke, and serious adverse events (P < .05 for all), but these were no longer significant after accounting for key clinical factors (P > .05 for all). Intensive blood pressure lowering reduced the primary efficacy endpoint and increased the primary safety endpoint compared with standard targets, consistently across the BMI spectrum (Pinteraction > .05). Conclusion The overall efficacy and safety of intensive blood pressure lowering did not appear to be modified by baseline BMI among high-risk older adults.