Systolic Blood Pressure, Cardiovascular Mortality, and All-Cause Mortality in Normoglycemia, Prediabetes, and Diabetes

BACKGROUND: The optimal blood pressure (BP) level for diabetic patients remains controversial, while studies provided limited evidence on BP management for individuals with normoglycemia or prediabetes. We aimed to investigate the associations between systolic blood pressure (SBP) and all-cause and cardiovascular (CVD) mortality among US adults with different glycemic profiles. METHODS: We used data from the 1999–2014 National Health and Nutrition Examination Survey (NHANES, n=40,046) with comprehensive baseline examination and follow-up assessment. Restricted cubic spline analysis was performed to examine dose–response relationship between SBP and mortality risk. Cox regression models were used to estimate hazard ratios of all-cause mortality and CVD mortality for SBP categories. RESULTS: U-shaped associations between SBP and all-cause mortality were observed regardless of glucose status. The relationship between SBP and CVD mortality was found to be U-shaped only in normoglycemic participants. The lowest mortality risk of optimal SBP (mmHg) by group was 115–120 (normoglycemia), 120–130 (prediabetes), and 125–135 (diabetes). When compared with the reference group, SBP < 100 mmHg was significantly associated with 49% (HR=1.49, 95% CI: 1.13–1.96), 57% (1.57, 1.07–2.3), and 59% (1.59, 1.12–2.25) higher all-cause mortality risk in people with normoglycemia, prediabetes, and diabetes, respectively. The multivariable-adjusted HRs of all-cause mortality for SBP ≥150 mmHg were 1.51 (1.25–1.82), 1.56 (1.27–1.93), and 1.33 (1.08–1.64), respectively. As for CVD mortality, the multivariable-adjusted HRs were 2.85 (1.29–6.33) for SBP <100 mmHg and 2.71 (1.56–4.69) for SBP ≥150 mmHg in normoglycemia; HR was 1.66 (1.05–2.63) for SBP ≥150 mmHg in diabetic patients. CONCLUSION: U-shaped relationships between SBP and all-cause mortality were observed regardless of diabetes status. The optimal SBP range was gradually higher with worsening glucose status.