Variation of ambulatory blood pressure in healthy middle-aged men

The majority of the reference data on ambulatory blood pressure (ABP) monitoring is based on fixed, predefined times for waking hours and sleep. Our aim was to determine the level of ABP according to diary entries when awake, at work, at home and during sleep in a sample of normotensive, middle-aged men. The dipping-status was also determined. All measurements were taken with a non-invasive auscultatory device on a normal working day. A total of 62 clinically healthy, normotensive men without a history of elevated BP were included. The mean resting BP of the group was 122/73 mm Hg. The 24-h systolic BP (SBP) was 114.4 +/- 8.6 mm Hg (95% CI 112.3, 116.6), while the diastolic BP (DBP) was 80.4 +/- 7.2 mm Hg (95% CI 78.5, 82.2). SBP when awake was 120.5 +/- 9.4 mm Hg (95% CI 118.1, 122.9) and diastolic pressure 84.4 +/- 7.7 mm Hg (95% CI 82.5, 86.4). The corresponding values for systolic and diastolic pressures during sleep were 101.2 +/- 8.5 mm Hg (95% CI 99.1, 103.4) and 71.7 +/- 7.7 mm Hg (95% CI 69.7, 73.6). The difference between day and night was 19.2 +/- 7.0 mm Hg for systolic and 12.7 +/- 6.0 mm Hg for diastolic pressure. The number of men whose systolic and diastolic pressure dropped less than 10% while asleep (non-dippers) was eight (13%) and 15 (24%), respectively. If the mean +/- 2 standard deviation interval is considered, the range of normality averaged 102-139/69-100 mm Hg when awake, 84-118/56-87 mm Hg when asleep and 97-132/66-95 over 24 h. The awake-sleep pressure difference did not correlate with the 24-h average.