Influences of cardiovascular disease on the relationship between baseline systolic blood pressure and adverse outcomes in diabetes: insights from large population-based study

Abstract Objective To evaluate the influences of cardiovascular disease (CVD) on the relationship between baseline systolic blood pressure (SBP) and adverse outcomes in diabetes. Methods This is an observational study of 16431 community-dwelling adults with diabetes and 7.8% had CVD. The relationship between SBP (either as a categorical or continuous variable) with major adverse cardiovascular event (MACE) and all-cause death were evaluated by baseline CVD status using multivariable-adjusted Cox proportional hazard models and restricted cubic spline. Results After a median follow-up of 3.4 years, 2145 (13.1%) MACE and 1025 (6.2%) all-cause death occurred. In the overall participants there was a linear relationship between SBP and MACE (P-nonlinear=0.55) and a U-shaped relationship between SBP and all-cause death (P-nonlinear=0.002). In participants free of CVD, in reference to SBP < 120 mmHg group, the risks for MACE increased as SBP category (120-129, 130-139, and ≥ 140 mmHg) advanced (P-trend < 0.001) and there was a linear relationship (P-nonlinear=0.75; Figure 1A); while the risks for all-cause death were lower in SBP of 120-139 mmHg and 140-159 mmHg groups while higher in SBP ≥ 160 mmHg group, and there was a U-shaped relationship (P-nonlinear<0.001; Figure 1B). Notably, in participants with existing CVD the relationship between SBP with MACE and all-cause death did not show any specific pattern. Conclusion The relationship between baseline SBP with MACE and all-cause death varied substantially by baseline CVD status. Future studies to investigate the threshold of initiating BP-lowering treatment and the appropriate BP target in diabetes may consider applying a CVD-based stratification strategy.