Impact of prehypertension on carotid artery intima–media thickening: Actual or masked?

Abstract

BackgroundRecent studies have reported that prehypertension is associated with increased values of common carotid artery intima–media thickness (CCA-IMT). The aim of this study was to assess the impact of daytime ambulatory blood pressure (BP) levels on the association of prehypertension with CCA intima–media thickening in prehypertensive subjects. MethodsA total of 807 subjects with office systolic BP<140 and diastolic BP<90mmHg, underwent 24h ambulatory BP (ABP) monitoring and carotid artery ultrasonographic measurements. The study population was divided into 3 groups according to office and daytime ABP levels: (1) normotensives: subjects with office BP<120/80mmHg and daytime ambulatory BP values within the normal range, (2) actual prehypertensives: individuals with office SBP (120–139mmHg) and/or DBP (80–89mmHg) and daytime ambulatory BP values within the normal range and (3) prehypertensives with masked hypertension (MH): patients with office SBP (120–139mmHg) and/or DBP (80–89mmHg) and elevated daytime ambulatory BP values. ResultsPrehypertensive patients with MH had higher (p<0.01) CCA-IMT values (0.712mm; 95%CI: 0.698–0.725) than actual prehypertensives (0.649mm; 95%CI: 0.641–0.656) and normotensives (0.655mm; 95%CI: 0.641–0.670) even after adjustment for baseline characteristics. Normotensives and actual prehypertensives did not differ significantly regarding CCA-IMT values (p>0.05). After adjusting for potential confounders, (including demographic characteristics, vascular risk factors, and office BP) prehypertension with MH was independently (p<0.01) associated with a 0.06mm increment in CCA-IMT (95%CI: 0.03–0.09). ConclusionsPatients with office BP levels in the prehypertensive range, who also have elevated daytime ABP levels, had higher CCA-IMT values than patients with prehypertension with normal daytime ABP values and normotensive individuals.