Analysis of 24-hour ambulatory blood pressure in prehypertensive subjects

AIM: To explore the characteristics of ambulatory blood pressure monitoring(ABPM) in prehypertensive subjects.METHODS: According to resting blood pressure levels,392 subjects were divided into three groups: normotensive group(n=82),prehypertensive group(n=183) and essential hypertensive group(n=127).A 24-h ABPM was performed in all patients.RESULTS: The 24-h BP variation coefficient of SBP(24-h SSD) in normotensive,prehypertensive and hypertensive subjects were,respectively,(14.0±2.1)%,(17.2±3.2)% and(20.5±4.6)%.The 24-h BP variation coefficient of DBP(24-h DSD) was(10.4±1.9)%,(13.1±1.9)% and(16.3±2.1)%,and the proportion of non-dipper blood pressure was 7%,25% and 39%.SBP load(SBP-L) was(35±20)% and DBP load was(33±20)%(P0.05,P0.01).The rate of decrease of SBP at night(SBPF) was 13% and the rate of decrease of DBP at night(DBPF) was 11%,lower than that of the normotensive group but higher than that of the hypertensive group(P0.01).CONCLUSION: The circadian pattern of BP significantly changed in the prehypertensive group.BP level,BP variability rate,BP load rate,and the proportion of non-dipper BP all increased,whereas SBPF and DBPF decreased.