Fig. 1

Circadian measurements of arterial blood pressure at the level of the upper arm (90217A Spacelabs Healthcare). Measurements every 15 minutes from 06 h - 22 h; every 30 minutes from 22 h - 06 h. Number of measurements performed: 91; successful measurements: 67 (86%); number of day-time (07-20 h) measurements: 42; number of night-time (patient supine, 20-07 h) measurements: 25. Horizontal bars indicate upper and lower limits of normal values: 135 and 85 mm Hg (day-time); 120 and 70 mm Hg (night-time), respectively systolic and diastolic