Isolated increases in in-office pressure account for a significant proportion of nurse-derived blood pressure-target organ relations.
OBJECTIVE
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 (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 (≥15 mmHg) showing the most marked increases in LVMI (P<0.0005) and PWV (P<0.0001) as compared to the lowest quartile (<-5 mmHg). 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.


CONCLUSIONS
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.
Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Muzi J
MJ
Maseko
Angela J
AJ
Woodiwiss
Olebogeng H I
OH
Majane
Carlos D
CD
Libhaber
Richard
R
Brooksbank
Gavin R
GR
Norton
D000328:Adult; D001794:Blood Pressure; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009740:Nursing Staff; D057184:Practice Patterns, Nurses'