We compared a convenient, cuffless, wrist-type ambulatory blood pressure monitoring (ABPM) device (BPro) and a standard arm-type ABPM monitor under ambulatory conditions.
Fifty normotensive and prehypertensive volunteers who had no interarm differences in BP were enrolled. The wrist and arm monitors were attached to the left wrist and the right arm, respectively, and provided readouts at 15 and 30-min intervals, respectively. Ambulatory BP levels and the extent of agreement by intraclass correlation were evaluated. In 15 of the 50 participants, we also examined values at different arm positions: heart level, above the head, and hanging at the sides.
The awake mean systolic blood pressure (SBP) values (122±13 vs. 127±11 mmHg, P<0.01) were significantly lower with the wrist monitor than the arm monitor, and the mean sleep diastolic blood pressure (DBP) (71±8 vs. 64±8 mmHg, P<0.01) was significantly higher with the wrist monitor than the arm monitor. The intraclass correlation values between the monitors were 0.54 for 24 h SBP and 0.52 for awake SBP, considered to indicate a moderate agreement. The BP values in the arm-raised position were significantly higher for the wrist monitor than for the arm monitor (SBP: 129±14 vs. 108±14 mmHg, P<0.01; DBP: 83±13 vs. 64±11 mmHg, P<0.01). However, the SBP and DBP values in the other arm positions were similar between the monitors.
The wrist monitor showed fair agreement with the arm monitor in the ambulatory condition, and was stable irrespective of arm positions.