From the database of 348 patients with essential hypertension, we analyzed the seven day mean blood pressure from seven day/ 24 hour ambulatory monitoring and we studied the relationship between age and circadian blood pressure variation.Design and Method:
Three hundred and forty-eight patients in the age from 20 to 82 years, were ambulatory monitored for seven-day/24 hour. Medical instruments (A&D, Japan) were used for ambulatory blood pressure monitoring (oscillation method, 30-minute interval between measurements). We calculated mean values of seven day/24 hour monitoring for systolic and diastolic blood pressure (M) and mean value of amplitude ( of the curve (double amplitude corresponds to the night-day difference) were evaluated double amplitude (2A).Results:
Mean values of seven day/24hour systolic and diastolic blood pressure of M (±SD) for the whole group were: SBP was 125 ± 8mmHg, DBP was 76 ± 6 mmHg, HR was 71 ± 6 bpm; of 2A: SBP – 21 ± 7, DBP – 15 ± 5 mmHg, HR – 15 ± 6 bpm. The linear relationship between M of SBP and age (r = 0.34, p< 0.001) and DBP and age (r = 0.39, p<0.001) was found (difference between age 20 and 77 years: SBP – 16 mmHg, DBP-12 mmHg). 2A of SBP and DBP was increasing with age up to 35 years, then the curve remained relatively flat up to 55 years (maximum at 45 years) and then decreased again (difference between 45 and 77 years: SBP was 13mmHg, DBPwas12 mmHg). Heart rate values of M and 2A were age-independent.Conclusions:
Seven day /24 hour blood pressure monitoring showed that mean values of seven day/24 hour blood pressure of SBP were increasing with age up to 75 years, night-day difference of SBP and DBP reached the maximum value at 45 years and then decreased.