Blood Pressure Levels and Outcomes in Type 2 Diabetes: Dose-Response Meta-Analysis of 5.87 Million Cohort Participants.

Abstract

The dose-response relationships between systolic and diastolic blood pressure (SBP and DBP) levels and risks of all-cause mortality, cardiovascular and renal outcomes in type 2 diabetes remain poorly characterized, particularly at lower blood pressure (BP) levels. This study aimed to examine risk patterns of major clinical outcomes across a wide range of BP levels in participants with type 2 diabetes. We systematically searched PubMed, Embase, and Web of Science from inception to November 30, 2024, for cohort studies assessing associations of BP levels with all-cause mortality, cardiovascular, and renal outcomes. One-stage mixed-effects dose-response meta-analysis was conducted to assess the curvilinear associations. A total of 89 cohorts from 113 articles of 5,875,364 participants with type 2 diabetes were identified. A J-shaped association was observed for SBP with all-cause mortality. J-shaped associations were also observed for SBP with cardiovascular events and for DBP with all-cause mortality, with flattened risks at lower BP levels. After excluding studies with participants who had baseline cardiovascular diseases or cancer, a significantly lower risk of cardiovascular events was observed at lower SBP levels, as well as a flattened risk of all-cause mortality. Positive linear or monotonic trends were observed for renal events, estimated glomerular filtration rate decline, and development or progression of albuminuria. In type 2 diabetes, BP is linearly or monotonically associated with most cardiovascular and renal outcomes. Low SBP does not appear to be associated with an elevated risk of all-cause mortality compared with higher BP targets, suggesting that previously reported associations are likely due to reverse causation and unmeasured confounding.