ANALYSIS OF 24-H BLOOD-PRESSURE PROFILE BY FOURIER-SERIES DURING LACIDIPINE THERAPY

In the present study, we examined the circadian profile of blood press ure (BP) in 10 patients with moderate essential hypertension before an d after 6 months of lacidipine therapy. Ambulatory BP was measured at 30-min intervals using SpaceLabs 90207. To account for the unequal tim e intervals between successive readings, BP means and variances were w eighted for the time span between successive readings, and weighted li near-regression analysis was applied. The 24-h BP values were carried out using Fourier analysis, comparing the values from the baseline wit h those after 24 weeks of lacidipine. After 24 weeks,BP values showed a significant decrease compared with baseline values (all p < 0.01). T he daily BP curves obtained from Fourier analysis with four harmonics showed that the significant circadian rhythm in nine patients was not altered by lacidipine treatment. The night/day differences were statis tically significant at 24 weeks vs. 0 week (all p < 0.01). The overall amplitude and acrophase of the BP curve were statistically significan t at 24 weeks (all p < 0.01). After 24 weeks of lacidipine therapy, ac cording to the nocturnal BP fall, we found three intermediate dippers, six dippers, and one non-dipper. By use of the two-step Fourier analy sis method, which provides a formal and statistical method to evaluate the presence of a significant diurnal BP rhythm and parametrization o f the 24-h BP recordings, we showed that lacidipine long-term therapy is effective in lowering BP and preserving the diurnal BP rhythm.