Abnormal Central Pulsatile Hemodynamics in Adolescents With Obesity: Higher Aortic Forward Pressure Wave Amplitude Is Independently Associated With Greater Left Ventricular Mass.
We hypothesized that increased aortic forward pressure wave amplitude (Pf), which is determined by characteristic impedance (Zc) in the proximal aorta, is the primary hemodynamic determinant of obesity-associated higher left ventricular (LV) mass in adolescents. Aortic pulsatile hemodynamics were measured noninvasively in 60 healthy adolescents (age 14-19 years; 42% male; 50% black) by sequential recordings of pulse waveforms via tonometry, brachial blood pressure, and pulsed Doppler and diameter of the LV outflow tract using 2-dimensional echocardiography. Adolescents who were overweight/obese (n=23; age 16.0±0.3 years; body mass index ≥85th percentile) had higher LV mass index, brachial and carotid systolic blood pressure and pulse pressure, normalized Zc and Pf compared with adolescents with healthy weight (n=37; 16.7±0.3 years; body mass index <85th percentile, all P<0.01). In contrast, there was no difference in mean or diastolic blood pressure, carotid-femoral pulse wave velocity, carotid augmentation index, or aortic backward wave amplitude (all P>0.05). Stepwise multiple linear regression analysis that included age, sex, race, normalized Zc, and brachial systolic blood pressure revealed that body mass index (B±SE; 0.49±0.20, P=0.02, R2=0.26), aortic Pf (0.22±0.07; P<0.02, R2change=0.11), and cardiac output (2.82±1.02, P<0.01; R2change=0.08) were significant correlates of LV mass index (total R2=0.44, P<0.01). These findings suggest that higher aortic Pf is a major hemodynamic determinant of increased LV mass in adolescents with elevated adiposity. Improper matching between aortic diameter and pulsatile flow during early systole potentially contributes to the early development of LV hypertrophy in childhood obesity.
From the Department of Health and Human Physiology (G.L.P.), Abboud Cardiovascular Research Center (G.L.P.), Center for Hypertension Research (G.L.P.), and Fraternal Order of Eagles Research Center (G.L.P.), University of Iowa, Iowa City; and Divisions of Pediatric Cardiology (A.D.P., G.K.K.) and Department of Pediatrics, Georgia Prevention Institute, Medical College of Georgia (M.P., K.D.-W.-A-S., G.K.K.), Augusta University. gary-pierce@uiowa.edu.
Gary L
GL
Pierce
From the Department of Health and Human Physiology (G.L.P.), Abboud Cardiovascular Research Center (G.L.P.), Center for Hypertension Research (G.L.P.), and Fraternal Order of Eagles Research Center (G.L.P.), University of Iowa, Iowa City; and Divisions of Pediatric Cardiology (A.D.P., G.K.K.) and Department of Pediatrics, Georgia Prevention Institute, Medical College of Georgia (M.P., K.D.-W.-A-S., G.K.K.), Augusta University.
Mohanasundari
M
Pajaniappan
From the Department of Health and Human Physiology (G.L.P.), Abboud Cardiovascular Research Center (G.L.P.), Center for Hypertension Research (G.L.P.), and Fraternal Order of Eagles Research Center (G.L.P.), University of Iowa, Iowa City; and Divisions of Pediatric Cardiology (A.D.P., G.K.K.) and Department of Pediatrics, Georgia Prevention Institute, Medical College of Georgia (M.P., K.D.-W.-A-S., G.K.K.), Augusta University.
Amy
A
DiPietro
From the Department of Health and Human Physiology (G.L.P.), Abboud Cardiovascular Research Center (G.L.P.), Center for Hypertension Research (G.L.P.), and Fraternal Order of Eagles Research Center (G.L.P.), University of Iowa, Iowa City; and Divisions of Pediatric Cardiology (A.D.P., G.K.K.) and Department of Pediatrics, Georgia Prevention Institute, Medical College of Georgia (M.P., K.D.-W.-A-S., G.K.K.), Augusta University.
Kathryn
K
Darracott-Woei-A-Sack
From the Department of Health and Human Physiology (G.L.P.), Abboud Cardiovascular Research Center (G.L.P.), Center for Hypertension Research (G.L.P.), and Fraternal Order of Eagles Research Center (G.L.P.), University of Iowa, Iowa City; and Divisions of Pediatric Cardiology (A.D.P., G.K.K.) and Department of Pediatrics, Georgia Prevention Institute, Medical College of Georgia (M.P., K.D.-W.-A-S., G.K.K.), Augusta University.
Gaston K
GK
Kapuku
D000293:Adolescent; D062186:Arterial Pressure / Q000502:physiology*; D001823:Body Composition; D015992:Body Mass Index; D015331:Cohort Studies; D004452:Echocardiography / Q000379:methods; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D063766:Pediatric Obesity / Q000150:complications* / Q000175:diagnosis; D011673:Pulsatile Flow / Q000502:physiology*; D063177:Pulse Wave Analysis; D012016:Reference Values; D018570:Risk Assessment; D059289:Vascular Stiffness / Q000502:physiology; D055815:Young Adult
adiposity; adolescents; cardiac output; pediatrics; pulse wave velocity