24 H Ambulatory Blood Pressure Variability and Carotid Artery Damage: Baseline Data from the Elsa Study.
Aim of our study was to evaluate the relationship of carotid intima-media thickness (IMT) with clinic (C) and 24 h ambulatory blood pressure (ABP) and with 24 h BP variability (V), from baseline data of the European Lacidipine Study on Atherosclerosis (ELSA). Design and Methods: In 1663 hypertensive patients in washout from treatment (56.2± 7.6 years; 54.4% males) several measures of maximum IMT were obtained from up to 12 different carotid sites by intensively trained and repeatedly certified sonographers. CBP was the average of 3 sitting measurements. From ABP recordings (Spacelabs 90207 or Takeda TM2021) we obtained: 1) 24 h, day and night average SBP and DBP, 2) day-night SBP and DBP differences of means ( -Δ), 3) 24h, day and night SBP and DBP standard deviations (SD, measure of BPV).Similar calculations were done for PP and HR. The influence of ABP and C variables on IMT was investigated by univariate and multiple regression analyses. Results: In the univariate analysis IMT was not related to C or 24h DBP, but was significantly related to C SBP (r from 0.16 to 0.21; p<0.001 for all), to C PP (r from 0.18 to 0.23; p<0.001) and even more to 24h SBP (r from 0.17 to 0.23; p<0.001) and to 24h PP (r from 0.24 to 0.32; p<0.001). In the multiple regression analysis, after accounting for age and average 24 h SBP or PP (p<0.001), IMT was positively associated with SBP and PP 24h SD (p<0.001) and negatively with SBP and PP day-night Δ and with 24h HR SD (p<0.05). Conclusions: This is the first demonstration from one of the largest available databases that the vascular adverse consequences of hypertension 1)are related more closely to 24h PP and SBP means than to C values, and 2)are related not only to mean BP levels but also to the degree of PP and SBP fluctuations over 24h.