Conventional and 24-h ambulatory blood pressure as independent predictors of elastic arterial properties

OBJECTIVE: No population study investigated whether 24-h ambulatory blood pressure (ABP) predicts distensibility of the elastic common carotid (DCar) and the muscular femoral (DFem) arteries over and beyond conventionally measured blood pressure (CBP). METHODS: At baseline, we measured CBP and 24-h ABP in 1063 randomly recruited participants (mean age, 44.3 years). CBP was the average of five consecutive readings obtained by trained observers at the participants' homes. We measured arterial distensibility by a wall-tracking ultrasound system, 21 months after CBP and ABP (5-95th percentile interval range, 13-33 months). RESULTS: Compared with men, women (49.2%) had higher (P<0.03) DCar (24.7 vs. 23.3 x 10(-3)/kPa) and higher DFem (10.6 vs. 9.2 x 10(-3)/kPa). In multivariate-adjusted models, including both CBP and ABP and stratified by sex, DCar was negatively related to systolic, diastolic, and mean arterial CBP in both sexes, and to diastolic ABP in women. DFem was inversely correlated with diastolic ABP in both sexes and with systolic and mean arterial ABP in men. Moreover, DFem was also negatively correlated with systolic and mean arterial CBP in men. In most instances, pulse pressure on CBP or ABP measurement did not predict DCar or DFem. No evidence of influential collinearity between CBP and ABP was observed. CONCLUSION: Depending on vascular territory, there is competition between highly standardized CBP and ABP in predicting DCar and DFem. These findings show that CBP under standardized conditions, and subject to rigorous quality control, is equally predictive of the elastic properties of large arteries as ABP.