3B.02

Abstract

Objective: Some studies suggested that ambulatory blood pressure (ABP) variability may provide useful information beyond that of average ABP levels. This study investigated the relationship between central ABP variability and target-organ damage in young individuals in whom the central-peripheral blood pressure discrepancy might be considerable. Design and method: Apparently healthy adolescents and young adults referred for elevated blood pressure and healthy volunteers (age 12–26 years) were subjected to: (i) 24-hour monitoring of central ABP using a noninvasive brachial cuff-based oscillometric device (Mobil-O-Graph 24 h PWA); (ii) 24-hour pulse wave velocity (PWV) monitoring (Mobil-O-Graph 24 h PWA); (iii) echocardiographic determination of left ventricular mass index (LVMI); (iv) measurement (ultrasonography) of the common carotid intima-media thickness (IMT). The standard deviation (SD) of ABP (24-hour weighted/awake/asleep), as well as the respective coefficients of variation (CV) were used for assessing variability. Results: The study included 68 individuals (mean age 18.7 ± 4.7 years, 52 males, body mass index [BMI] 24.5 ± 4.7 kg/m2, 24 volunteers, 15 with hypertension [24-hour peripheral ABP >=95th percentile for adolescents or >=130/80 mmHg for adults]). LVMI was correlated with 24-hour/awake/asleep central systolic ABP (r=0.50/0.49/0.40, all p < 0.01), as well as with 24-hour weighted/awake/asleep SD of central systolic ABP (r = 0.40/0.37/0.30, all p < 0.05), whereas no association was observed for the respective CV. IMT was correlated with 24-hour/awake/asleep central pulse pressure (PP) (r = 0.37/0.33/0.27, all p < 0.05), 24-hour weighted/awake/asleep SD of central PP (r = 0.43/0.40/0.36, all p < 0.01) and the respective CV (r = 0.28/0.26/0.25, all p < 0.05). Regarding 24-hour PWV, there was a significant association with 24-hour/awake/asleep central systolic ABP (r = 0.94/0.88/0.84, all p < 0.001) and 24-hour weighted/awake/asleep SD of central PP (r = 0.48/0.51/0.25, all p < 0.05), but not with the respective CV. In multivariate regression analyses (independent variables: age, gender, BMI, central ABP and SD/CV of ABP values), LVMI and 24-hour PWV were determined by BMI, age, and 24-hour central systolic ABP, and IMT by male gender and 24-hour weighted SD of central PP. Conclusions: In young individuals, 24-hour central ABP variability appears to be associated only with early carotid damage when accounting for ABP levels, whereas LVMI and PWV are mainly determined by average ABP levels.