Lack of adequate blood pressure control in the morning and evening periods in medicated hypertensive patients considered to be controlled in the office.

Background and Aim: In hypertensive patients tight blood pressure (BP) control during the critical morning and evening periods may be relevant for preventing cardiovascular events, which most frequently occur at these times of the day.
Methods: In a prospective study we evaluated 24h ambulatory BP (ABP) values (24h, daytime, nighttime, morning period between 6-10 am and evening period between 6-10 pm), in 103 hypertensive patients (HTs), aged between 18-79 years, considered to be controlled in the office in the previous two months (office BP < 140/90 mmHg, 2 x 3 readings, before taking medication), who were being treated with antihypertensive drugs taken once daily in the morning. Based on ABP data, HTs were considered to have good BP control if daytime BP values were < 135/85 mmHg, < 133.1/85.4 mmHg during the morning period, and < 138.1/89.3 mmHg during the evening period. Otherwise control of ABP was considered poor. These limits correspond to the upper 95% confidence limits of BP calculated for each period in a normotensive control population of 210 subjects age-matched to the HTs.
Results: Of the 103 HTs, 39 were under monotherapy and the remaining 64 on combination regimens (34 with two drugs, 29 with three and one with four). Based on ABP data of the 103 HTs, poor ABP control was observed in 36 (35%) in the morning period, in 24 (23%) in the evening period and in 29 (28%) for daytime BP values. ABP values during both the morning and evening periods correlated significantly with daytime values (r = 0.72 and r = 0.89 respectively, p < 0.01) but not with office values.
Conclusions: A significant proportion of treated HTs who are considered to be controlled in the office present abnormally high ABP levels, particularly in the critical early morning period, but also during the evening and throughout the daytime period.