Researchers looked at data for 13,792 people from the National Health and Nutrition Examination Survey, which enrolled participants in 1971-76 and followed them up for two decades. They studied DBP, SBP and long-term survival data specifically.
To assess the underlying distribution of untreated blood pressure in American adults by age, Taylor and team also looked at data for 6,672 adults from the first National Health Examination Survey carried out between 1959 and 1962.
They found that in people aged over 50, those with SBPs above 140, independent of DBP, were significantly more likely to die prematurely. In those aged 50 or less, DBPs above 100 were linked to significant increases in premature death. The authors' analysis offers alternative cut-off points for the definition of "normal."