Aortic Augmentation Index Is Inversely Associated With Cardiorespiratory Fitness in Men Without Known Coronary Heart Disease

• Published in: American journal of hypertension Vol. 19; no. 10; pp. 1019 - 1024
• Main Authors: Binder, Josepha, Bailey, Kent R., Seward, James B., Squires, Ray W., Kunihiro, Takamu, Hensrud, Donald D., Kullo, Iftikhar J.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2006; Oxford University Press; Elsevier Science
• Subjects: Adult; Aged; Aged, 80 and over; Aorta - physiology; Aorta - physiopathology; Aortic augmentation index fitness; Arterial hypertension. Arterial hypotension; arterial stiffness; Biological and medical sciences; Blood and lymphatic vessels; Blood Pressure - physiology; Cardiology. Vascular system; cardiorespiratory fitness; Cardiovascular Physiological Phenomena; Cardiovascular system; Coronary Disease - physiopathology; Coronary heart disease; Heart; Humans; Investigative techniques of hemodynamics; Investigative techniques, diagnostic techniques (general aspects); Linear Models; Male; Medical sciences; Middle Aged; Multivariate Analysis; Oxygen Consumption - physiology; Physical Fitness - physiology; Respiratory Physiological Phenomena; wave reflection; arterial stiffness; cardiorespiratory fitness; wave reflection; Aortic augmentation index fitness; Human; Hypertension; Aorta; Cardiovascular disease; Stiffness; Coronary heart disease; Fitness
• ISSN: 0895-7061; 1879-1905; 1941-7225
• DOI: 10.1016/j.amjhyper.2006.02.012

We investigated whether the aortic augmentation index (AIx), a measure of arterial wave reflection and stiffness, is associated with cardiorespiratory fitness in men without known coronary heart disease (CHD). Asymptomatic men ( n = 201, mean age 51 ± 9.2 years) referred for a screening exercise electrocardiogram (ECG) underwent applanation tonometry to obtain radial artery pulse waveforms, and an ascending aortic pressure waveform was derived by a transfer function. The AIx is the difference between the first and second systolic peak of the ascending aortic pressure waveform, expressed as a percentage of the pulse pressure. Cardiorespiratory fitness was assessed by maximal oxygen consumption (VO 2 max mL/min/kg) during a symptom-limited graded exercise test. Multivariable regression analyses were used to identify significant independent determinants of AIx and of VO 2 max. Diabetes was present in 2.5% of subjects, 34.8% had history of smoking, and 29% were hypertensive. Mean (± SD) AIx was 19.9% ± 9.0% and mean VO 2 max was 33.9 ± 6.4 mL/min/kg. In a multivariable linear regression model, AIx was positively associated with age, hypertension, and history of smoking and inversely with heart rate, height, and body mass index (BMI). The VO 2 max was significantly inversely related to AIx after adjustment for age, heart rate, height, and BMI ( r = −0.22, P = .002), after further adjustment for CHD risk factors (total cholesterol, HDL-cholesterol, history of smoking, diabetes, hypertension) ( P = .006), and after additional adjustment for behavioral factors (physical activity score, alcohol intake, and percent body fat) ( P = .022). These findings indicate that AIx, a measure of arterial wave reflection and stiffness, is inversely associated with cardiorespiratory fitness in men without CHD.