Lacidipine and Blood Pressure Variability in Diabetic Hypertensive Patients

Abstract

The aim of our study was to assess the effects of lacidipine, a long-acting calcium antagonist, on 24-hour average blood pressure, blood pressure variability, and baroreflex sensitivity. In 10 mildly to moderately hypertensive patients with type II diabetes mellitus (aged 18 to 65 years), 24-hour ambulatory blood pressure was continuously monitored noninvasively (Portapres device) after a 3-week pretreatment with placebo and a subsequent 4-week once daily lacidipine (4 mg) or placebo treatment (double-blind crossover design). Systolic blood pressure, diastolic blood pressure, and heart rate means were computed each hour for 24 hours (day and night) at the end of each treatment period. Similar assessments were also made for blood pressure and heart rate variability (standard deviation and variation coefficient) and for 24-hour baroreflex sensitivity, which was quantified (1) in the time domain by the slope of the spontaneous sequences characterized by progressive increases or reductions of systolic blood pressure and RR interval and (2) in the frequency domain by the squared ratio of RR interval and systolic blood pressure spectral power approximately 0.1 and 0.3 Hz over the 24 hours. Compared with placebo, lacidipine reduced the 24-hour, daytime, and nighttime systolic and diastolic blood pressure (P<0.05) with no significant change in heart rate. It also reduced 24-hour, daytime, and nighttime standard deviation (-19.6%, -14.4%, and -24.0%, respectively; P<0.05) and their variation coefficient. The 24-hour average slope of all sequences (7.7+/-1.7 ms/mm Hg) seen during placebo was significantly increased by lacidipine (8.7+/-1.8 ms/mm Hg, P<0.01), with a significant increase being obtained also for the 24-hour average alpha coefficient at 0.1 Hz (from 5.7+/-1.5 to 6.4+/-1.3 ms/mm Hg, P<0.01). Thus, in diabetic hypertensive patients, lacidipine reduced not only 24-hour blood pressure means but also blood pressure variability. This reduction was accompanied by an improvement of baroreflex sensitivity. Computer analysis of beat-to-beat 24-hour noninvasive blood pressure monitoring may offer valuable information about the effects of antihypertensive drugs on hemodynamic and autonomic parameters in daily life.