Background 24-hour ambulatory blood pressure monitoring (ABPM) is commonly used in evaluation of hypertension. One of the parameters describing circadian blood pressure profile is blood pressure variability expressed as a SD (standard deviation) of a given time period. This parameter is interesting because of its assumed influence on development of hypertension complications. Another method for describing the diurnal blood pressure curve is dippers/nondippers classification. Lack of nocturnal blood pressure fall increases the risk of hypertensive end-organ damage.
Material and methods 3 groups (13 patients in every group) with essential mild-to-moderate hypertension. Each of the groups was treated with monotherapy based on a long-acting hypertensive drug given once daily: trandolapril, felodipine ER or rilmenidine. After one month of morning administration (MA) it was changed into evening routine (EA). In every patient office blood pressur (OBP) and ABPM was taken 3 times: before enrolling, after one month of MA and after one month of EA.
Results In each of examined groups, in MA and EA routine, there was significant lowering of blood pressure both in ABPM and OBP. Independent of drug used or the time of administration there were no differences in SD for different time periods in ABPM. There were no differences in requency of non-dippers among hypertensives before and after treatment (for both administration routines).
Conclusion We have shown that although 24-hour average blood pressure can be effectively reduced by antihypertensive treatment, the effect on blood pressure variability and dippers or non-dippers status is less pronounced.