Analysis of the diurnal variations in ambulatory blood pressure and their cardiovascular consequences

Objective: to study the relationships between evolution of changes in blood pressure (BP) over the 24 hour cycle and their cardiac and vascular conseq uences in mild to moderate hypertensive (HT) subjects (WHO criteria). Material and methods: 151 patients presenting with mild to moderate essenti al HT (Age 49 +/- 12 yrs, 63 M 44W) - ambulatory measurement of BP over 24 hours (Spacelabs 90207) automatic determination of the diurnal cycle by Fou rier analysis (5 harmonics) and calculation of the slope of BP variation (m mHg/hr) at the point of transition from day to night (nocturnal dip slope ( NDS)), and at the change from night to day (morning rise slope (MRS). Patie nts with inversion of the day-night cycle were excluded, day-night being ar bitrarily defined as 7 to 22h and 22 to 7h. Echography of left ventricular mass index (LVMI) / Penn convention, formula of Devereux, and carotido-femoral distensibility by pulse wave velocity (P WV, Complier Colson France). Results: ambulatory measures of BP and HR and of cardiovascular parameters were as follows. [GRAPHICS] The slope of nocturnal fall (NDS) and morning rise in SEP (MRS) is signific antly correlated with LVMI (NDP r=-0.02, p=0.049, MPP r=0.21, p=0.029) and with PWV (MPP: r=0.32, p=0.005). No relationship was found with the DBP val ues. By multivariate analysis taking into account age, sex, 24h SEP, MPP sl ope Velocity was the only variable which was significantly related with the model of PWV and LVMI (p<0.001). Conclusion: Dipper and non-dipper studies have been performed to examine th e consequences of day night variations in BP. The evolution of diurnal chan ges in BP seems to have an effect on the Vessels and heart and may be a sim ple analysis toot for assessing prognosis and therapeutic effects.