Systolic and mean arterial blood pressure should be the routine measures of blood pressure in healthy patients, with an optimal interval for rescreening of three years, UK-led research has found.
The cohort study took annual blood pressure measurements from 15,055 healthy Japanese adults, with a mean age of 49 years, who were not taking hypertensive medication.
The reasoned that a true increase of a participant's blood pressure level consists of the average change of the whole group over time, the signal, and the short-term within-person variance around the average change, the noise.
Researchers calculated the ratio of signal to noise, arguing that to be a good monitoring test, the signal needs to be large relative to noise and when the ratio was 1:1 the screening interval was appropriate.
After three years the signal of SBP and MAP equalled the noise of blood pressure measurement in patients with SBP less than 130mmHg and 2 years for those with SBP of 130mmHg or more.
Study leader Dr Osamu Takahashi, a research fellow at the University of Oxford, concluded: ‘Our findings support that SBP or MAP appears to be better long-term monitoring measures than DBP and PP. The optimal measurement interval should be at least three years for healthy adults not taking antihypertensive medications.'