Differences Between Brachial And Aortic Blood Pressure In Adolescence and their implications for diagnosis of hypertension

Objectives Blood pressure is the leading global cause of mortality, and its prevalence is increasing in children and adolescents. Aortic blood pressure (BP) is lower than brachial BP in adults. We aimed to assess the extent of this difference and its impact on the diagnosis of hypertension among adolescents. Methods We used data from 3850 participants from a UK cohort of births in the early 1990s in the Southwest of England, who attended their ∼17 year follow-up and had valid measures of brachial and aortic BP at that clinic (mean(SD) age 17.8(0.4)y, 66% female). Data are presented as mean differences [95% prediction intervals] for both sexes. Results Aortic systolic BP was lower than brachial systolic BP (male, -22.3[-31.2, - 13.3]mmHg; female, -17.8[-25.5, -10.0]mmHg). Differences between aortic and brachial diastolic BP were minimal. Based on brachial BP measurements, 101 males (6%) and 22 females (1%) were classified as hypertensive. In contrast, only nine males (<1%) and 14 females (<1%) met the criteria for hypertension based on aortic BP, and the predictive value of brachial BP for aortic hypertension was poor (positive predictive value = 13.8%). Participants with aortic hypertension had a higher left ventricular mass index than those with brachial hypertension. Conclusions Brachial BP substantially overestimates aortic BP in adolescents due to marked aortic-to-brachial pulse pressure amplification. The use of brachial BP measurement may result in an overdiagnosis of hypertension during screening in adolescence.