Reproducibility Of Ambulatory Blood Pressure Monitoring In The Very Elderly Hypertensives

Objective: Ambulatory blood pressure monitoring (ABPM) are widely used for diagnosis and treatment of hypertension currently. It has been demonstrated that 24-hour mean blood pressure, ambulatory pulse pressure, blood pressure variability and other parameters of ABPM are not only correlated to target-organ damage,but also are risk markers of cardiovascular events in the hypertensive patients. Howerver, the value of science lie with the reproducibility, so does the ABPM. Studies showd that the reproducibility of ABPM was better than those of office blood pressure and home blood pressure. In recent years, the studies on the reproducibility of ABPM turn to special populations, such as pregnancy, renal transplant recipients, hemodialysis, elct. The characteristics of elder hypertensive patients include excessive variability, high systolic blood pressure, widely pulse pressure, and so on. Data on the reproducibility of serial measurements of ambulatory blood pressure in the very elderly hypertensive patients are lacking compared common hypertensives. The purpose of this study is to examine the reproducibility of parameters of ambulatory blood pressure measurements in the very elderly hypertensive patients with age≥80 years old.Methods: Fifty essential hypertensive patients with 140 mmHg≤systolic blood pressure(SBP) < 180mmHg,and 90 mmHg≤diastolic blood pressure (DBP)<110mmHg by office mercury sphygmomanometer,whose aged≥80 years old, were inclueded from the Department of Geriatrics of this hospital. 48-houres ABPM was then recorded consecutively at the second morning after admission. Antihypertensive therapy was not adjusted within 15 days before admission. Mean values of blood pressure over 24-hour mean systolic blood pressure(24HMSBP), 24-hour mean diastolic blood pressure(24HMDBP), daytime mean systolic blood pressure(DMSBP), daytime mean diastolic blood pressure(DMDBP), nighttime mean systolic blood pressures(NMSBP), nighttime mean diastolic blood pressure(NMDBP), 24-hour ambulatory pulse pressure (24HAPP), daytime ambulatory pulse pressure(DAPP), nighttime ambulatory pulse pressure(NAPP), systolic blood pressure load (SBPL), diastolic blood pressure load (DBPL), 24-hour heart rate (24HHR), maximum systolic blood pressure (MaxSBP), minimum diastolic blood pressure(MinDBP), as well as nighttime systolic blood pressure reduction rates (NSBPRR ) , nighttime diastolic blood pressure reduction rates (NDBPRR), 24-hour systolic blood pressure variability (24HSBPV), 24-hour diastolic blood pressure variability (24HDBPV), daytime systolic blood pressure variability(DSBPV), daytime diastolic blood pressure variability (DDBPV), nighttime systolic blood pressure variability (NSBPV) as well as nighttime diastolic blood pressure variability (NDBPV) of the first day and the second day were compared and the reproducibility of blood pressure measurements were investigated based on paired-samples t-test. P<0.05 was defined statistically significant differences.Results: All the included patients finished 48-hour ambulatory blood pressure measurement and the relative indices were calculated. The results were as follows: 24HMSBP(133.0±12.0 mmHg vs 131.7±12.2mmHg, P=0.25), 24HMDBP(70.7±6.8 mmHg vs 70.0±7.0 mmHg P=0.22), DMSBP(133.9±12.4 mmHg vs 133.2±12.8 mmHg P=0.61), DMDBP (71.7±6.6 mmHg vs 71.2±7.4 mmHg P=0.39), NMSBP(129.5±14.6 mmHg vs 125.7±15.2 mmHg P=0.06), NMDBP(66.5±10.0 mmHg vs 65.7±8.4 mmHg P>0.50), 24HAPP(62.2±9.2mmHg vs 61.6±11.0mmHg P=0.54), NAPP(63.0±11.4 mmHg vs 60.0±12.3 mmHg P=0.06), DAPP(62.2±9.5 mmHg vs 62.1±11.2 mmHg P=0.94), MaxSBP(171.9±16.0 mmHg vs 175.7±20.2 mmHg P=0.11), MinDBP(47.4±6.5 mmHg vs 46.4±5.8 mmHg P=0.29), SBPL(37.2±23.4% vs 35.3±21.9%, P=0.40), DBPL(7.2±10.1% vs 6.4±8.1% P=0.50), NSBPRR (3.1±8.7% vs 5.4±9.2% P=0.12), NDBPRR (7.3±10.1% vs 7.4±9.8% P=0.95), 24HDBPV(0.16±0.04, 0.17±0.05 P=0.12), NSBPV(0.12±0.05, 0.12±0.04 P=0.98), NDBPV (0.15±0.06, 0.15±0.07 P=0.84), 24HHR (68.0±8.2bpm vs 67.1±7.8bpm P=0.13). The results of above parameters are not significantly differenct, besides 24HSBPV(0.12±0.03 vs 0.15±0.04 P=0.01), DSBPV(0.13±0.03 vs 0.15±0.04 P=0.04), DDBPV(0.15±0.04, 0.17±0.05 P=0.02), which are different significantly between the first and second day.Conclusion: The reproducibility of ambulatory blood pressure recordings on two groups after admission by the ambulatory blood pressure monitoring in the very elderly hypertensive patients is very well in generally speaking. The blood pressure fluctuates in daytime, the main reason of which may be the serious atherosclerosis and daytime activity. There is diurnal rhythm after antihypertensive therapy. These findings suggest that ambulatory blood pressure monitoring is a reliable tool to monitor blood pressure changes, except for the indices of blood pressure variability.