Pressure response to successive clinic readings predicts an elevated blood pressure at 2.6 years' follow-up: The Israeli CORDIS study

Background: Many persons exhibit an elevation in blood pressure (BP) when examined in a medical setting. We examined whether individuals exhibiting an exaggerated pressure response (high responders) to BP determination would have an elevated baseline BP on followup, independent of the initial BP level. Methods and results: A total of 1217 employed men not on hypertensive medication, aged 20-64 years were examined over 2-4 years (mean 2.6 years) following the baseline measurements at entry. Pressure response was assessed at entry and defined as the difference between the first and fourth values in successive readings. Such a response was apparent for systolic BP (S (SBP) but was negligible for diastolic BP (DBP) and the former was negatively related to the baseline BP value. High responders were defined as persons showing a pressure response greater than the average for the respective subgroup with an initially similar baseline BP value. Logistic regression results indicated that those with high SBP responsivity had a 2.7 times greater chance of having an elevated SBP (≤ 140 mm Hg) on follow-up (95% Cl 1.8-4.1, P < 0.001), independently of initial SBP, age, or body mass index. Other significant predictors were the initial baseline SBP value and age. In those with an initial SBP of 130-139 mm Hg, the baseline SBP was not predictive of future readings whereas high responders had a four times higher risk of having an elevated SBP on follow-up (OR = 4.0, 95% Cl 2.0-8.0, P(0.001). Conclusions: These findings suggest that SBP hyper-responsivity to BP determination at the clinic independently predicts elevated SBP 2.6 years later. Further studies are warranted to determine the predictive value over a longer follow-up period.