Association between blood pressure levels and mortality in patients with type 2 diabetes: A retrospective cohort analysis

INTRODUCTION: The optimal blood pressure (BP) targets for patients with type 2 diabetes (T2D) remain debated among international guidelines. This retrospective cohort analysis evaluated the associations of specific systolic and diastolic BP (SBP and DBP) categories with long-term mortality in patients with T2D. MATERIALS AND METHODS: We analyzed 2,198 adults with T2D from the National Health and Nutrition Examination Survey (NHANES) 1999-2018. Participants were stratified by baseline SBP (<130, 130-140, ≥140 mmHg) and DBP (<80, 80-89, ≥90 mmHg). Multivariable Cox proportional hazards models were constructed to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, cardiovascular, cerebrovascular, and diabetes-related mortality, adjusting for comprehensive baseline covariates. RESULTS: Over a median follow-up of 97.0 months, an SBP ≥140 mmHg was significantly associated with elevated risks for all-cause (HR = 1.66, 95% CI: 1.28-2.16), cardiovascular (HR = 1.53, 95% CI: 1.10-2.13), cerebrovascular (HR = 3.98, 95% CI: 1.71-9.27), and diabetes-related mortality (HR = 1.84, 95% CI: 1.06-3.16) compared to an SBP <130 mmHg. Conversely, a DBP of 80-89 mmHg was associated with significantly lower all-cause (HR = 0.67, 95% CI: 0.46-0.98) and cardiovascular mortality (HR = 0.57, 95% CI: 0.35-0.93) than a DBP <80 mmHg, indicating a distinct J-curve phenomenon. CONCLUSIONS: In this observational study, baseline SBP <140 mmHg and DBP 80-89 mmHg were associated with favorable survival outcomes in patients with T2D. These findings suggest that individualized blood pressure management warrants further investigation, taking into account the limitations of observational data and single baseline measurements.