Measurement of Central Aortic Blood Pressure in Youth: Role of Obesity and Sex

BACKGROUND The relationship between pediatric severe obesity (SO) and central aortic blood pressure (BP) has yet to be established. METHODS We conducted a cross-sectional study of 348 youth (48.5% male, age 12.7 +/- 0.1 years) with a wide range of body mass index (BMI) values: normal weight (NW; >= 5th and <85th BMI percentiles), overweight/obesity (OW/OB; 85th to <120% of the 95th BMI percentile), and SO (>= 120% of the 95th BMI percentile). Measures of central aortic BP were obtained via applanation tonometry with SphygmoCor MM3 software. RESULTS After adjustment for covariates, no significant sex differences were observed for radial-aortic systolic blood pressure (SBP) (P = 0.39), carotid-aortic SBP (P = 0.99), radial-aortic diastolic blood pressure (DBP) (P = 0.44), and carotid-aortic DBP (P = 0.53). Compared to youth with NW, youth with SO exhibited higher radial-aortic SBP (SO vs. NW: 102 +/- 1 mm Hg vs. 90 +/- 1 mm Hg, P < 0.001), carotid-aortic SBP (SO vs. NW: 121 +/- 1 mm Hg vs. 109 +/- 1 mm Hg, P < 0.001), and carotid-aortic DBP (SO vs. NW: 60 +/- 1 mm Hg vs. 56 +/- 1 mm Hg, P = 0.04). Compared to youth with OW/OB, youth with SO had higher radial-aortic SBP (OW/OB: 97 +/- 1 mm Hg, P = 0.002) and carotid-aortic SBP (OW/OB: 114 +/- 1 mm Hg, P = 0.007). After adjusting for either total-body percent fat mass or visceral adipose tissue, BMI was still a significant predictor of both radial-aortic and carotid-aortic SBP and DBP (P<0.001, all). CONCLUSIONS In a cohort of youth with a wide range of adiposity levels, central aortic BP was elevated among individuals with SO and associated with BMI but not body fatness.