Abstract
Introduction:
Elevated blood pressure (BP) is recognized as the leading risk factor for cardiovascular disease (CVD). Low BP values are also markers of concurrent CVD. Our objective was to determine the association between systolic BP (SBP) and diastolic BP (DBP) with CVD mortality, comparing different BP ranges in a contemporaneous population.
Methods:
The National Health and Nutrition Examination Survey is a nationally representative survey of the US population. Our sample included data from 53,561 adult participants of the 1999-2018 cycles, with measured BP and mortality data available through 2019 linked from the National Death Index. BP was measured three times with a standardized sphygmomanometer and averaged. CVD mortality was defined through ICD-10 codes as diseases of the heart or cerebrovascular disease. We used age adjusted Poisson regression models to estimate incidence densities ratios (IDRs) for CVD mortality. All analyses accounted for the complex survey design.
Results:
The population was comprised of 51% women with a mean age of 46 years. After an average follow-up of 9.9 years, 7,825 (10.5%) died of any cause and 2,451 (3.1%) died of CVD. Compared with SBP 110 - < 120mmHg, CVD mortality did not differ at SBP 100-<100mmHg or 120-<130 mmHg, but was significantly higher by: 56% with SBP <100mmHg (IDR: 1.56, 95% CI: 1.15, 2.10), 21% with SBP 130 – < 140mmHg (IDR: 1.21, 95% CI: 1.04, 1.42), 36% with SBP 140 – < 160mmHg (IDR: 1.36, 95% CI: 1.14, 1.64), and 77% with SBP ≥160mmHg (IDR: 1.77, 95% CI: 1.47, 2.14). Compared with DBP 70 - < 80mmHg, CVD mortality was significantly higher by 64% with DBP < 50mmHg (IDR: 1.64, 95% CI: 1.38, 1.94), 46% with DBP 50 - < 60mmHg (IDR: 1.46, 95% CI: 1.26, 1.670), 24% with DBP 60 – < 70 mmHg (IDR: 1.24, 95% CI: 1.09, 1.41), 36% with DBP 80 – < 90mmHg (IDR: 1.36, 95% CI: 1.15, 1.61), 54% with DBP 90 – < 100mmHg (IDR: 1.54, 95% CI: 1.20, 1.97), and 182% with DBP ≥100mmHg (IDR: 2.82, 95% CI: 1.90, 4.19).
Conclusion:
Among US adults, we found a J shaped association between both SBP and DBP with CVD mortality. Lowest risk of CVD mortality was found at SBP 110 - < 120mmHg, with higher risk at levels below 100mmHg or at or above 130mmHg. For DBP, lowest risk of CVD mortality was found at DBP 70 - < 80mmHg, with higher risk at levels below 70mmHg or at or above 80mmHg.