Blood pressure variability assessed by office, home, and ambulatory measurements: comparison, agreement, and determinants.

The present study compared the blood pressure variability (BPV) among office (OBP), home (HBP), and ambulatory blood pressure (ABP) measurements and assessed their determinants, as well as their agreement in identifying individuals with high BPV. Individuals attending a hypertension clinic had OBP measurements (2-3 visits) and underwent HBP monitoring (3-7 days, duplicate morning and evening measurements) and ABP monitoring (24 h, 20-min intervals). BPV was quantified using the standard deviation (SD), coefficient of variation (CV), and variability independent of the mean (VIM) using all BP readings obtained by each method. A total of 626 participants were analyzed (age 52.8 ± 12.0 years, 57.7% males, 33.1% treated). Systolic BPV was usually higher than diastolic BPV, and out-of-office BPV was higher than office BPV, with ambulatory BPV giving the highest values. BPV was higher in women than men, yet it was not different between untreated and treated individuals. Associations among BPV indices assessed using different measurement methods were weak (r 0.1-0.3) but were stronger between out-of-office BPV indices. The agreement between methods in detecting individuals with high BPV was low (30-40%) but was higher between out-of-office BPV indices. Older age was an independent determinant of increased OBP variability. Older age, female sex, smoking, and overweight/obesity were determinants of increased out-of-office BPV. These data suggest that BPV differs with different BP measurement methods, reflecting different pathophysiological phenomena, whereas the selection of the BPV index is less important. Office and out-of-office BP measurements appear to be complementary methods in assessing BPV.