Isolated increases in in-office pressure account for a significant proportion of nurse-derived blood pressure-target organ relations

Aims:We determined the extent to which relationships between nurse-derived blood pressures (BPs) and cardiovascular damage may be attributed to isolated increases in in-office SBP independent of ambulatory BP.Methods:In 750 participants from a community sample, nurse-derived office BP, ambulatory BP, carotid-femoral pulse wave velocity (PWV; applanation tonometry and SphygmoCor software; n=662), and left ventricular mass indexed to height(2.7) (LVMI; echocardiography; n=463) were determined.Results:Nurse-derived office BP was associated with organ changes independent of 24-h BP (LVMI; partial r=0.15, P<0.005, PWV; partial r=0.21, P<0.0001) and day BP. However, in both unadjusted (P<0.0001 for both) and multivariate adjusted models (including adjustments for 24-h BP; LVMI; partial r=0.14, P<0.01, PWV; partial r=0.21, P<0.0001), nurse office-day SBP (an index of isolated increases in in-office BP) was associated with target organ changes independent of ambulatory BP and additional confounders, with the highest quartile (15mmHg) showing the most marked increases in LVMI (P<0.0005) and PWV (P<0.0001) as compared to the lowest quartile (<-5mmHg). These relationships were reproduced in those with normotensive day BP values and the quantitative effect of nurse office-day BP on target organ changes was at least equivalent to that of ambulatory BP.Conclusion:Nurse-elicited isolated increases in in-office BP account for a significant proportion of the relationship between nurse-derived BP and target organ changes independent of ambulatory BP. Therefore, high quality nurse-derived BP measurements do not approximate the impact of BP effects per se on cardiovascular damage.