Low Systolic Blood Pressure and Vascular Mortality Among Over One Million Korean Adults
Background—The association between low systolic blood pressure (SBP) and vascular disease is unclear, especially in non-clinical populations.
Methods and Results—We studied 1,235,246 individuals who participated in routine medical examinations between 1992 and 1995. The hazard ratios (HRs) were adjusted for potential confounders. During 22.7 million person-years of follow-up, 34,816 individuals died from atherosclerotic vascular diseases. An increase in SBP was directly related to an increase in vascular mortality down to around 100 mmHg. The group with the lowest SBP (<90 mmHg) had a higher HR for mortality from atherosclerotic vascular disease (HR=1.53, 95% CI=1.15-2.03) when compared to those with an SBP of 90-99 mmHg. The HR associated with the lowest SBP was 2.54 (95% CI=1.51-4.29) for ischemic heart disease and 1.21(95% CI=0.79-1.85) for stroke. Regarding stroke subtype, mortality from hemorrhagic stroke (HR per 10 mmHg increase=0.53, 0.29-0.96), rather than mortality from ischemic stroke (HR per 10 mmHg increase =1.00, 0.51-1.97), was inversely associated with SBP when SBP fell below 100 mmHg. Even when excluding the first 5 years of follow-up, the HRs associated with the lowest SBP did not decrease. The inverse association between SBP and vascular mortality in the range below 100 mmHg tended to be apparent in people aged 60-95 years, compared with individuals aged 30-59 years.
Conclusions—J-curve associations exist between SBP and vascular mortality, which reach a nadir at around 100 mmHg. SBP of less than 90 mmHg may portend death from vascular disease, particularly from ischemic heart disease.
- Received December 5, 2015.
- Revision received March 19, 2016.
- Accepted April 19, 2016.