Association of age with timing and amplitude of reflected pressure waves during exercise in men

Abstract

Background Increased elastic conduit artery stiffness with aging is associated with early wave reflection and increased wasted left ventricular pressure energy (LVE W). The effects of aging on central hemodynamics during exercise have not been well characterized. This study sought to investigate changes in central hemodynamics during cycle exercise in young, middle-aged, and older men.MethodsCentral blood pressure and wave reflection characteristics were measured noninvasively using radial artery applanation tonometry at rest and during cycling exercise (45, 55, and 65% of predicted maximum heart rate (HRmax)) in 14 young (24 1 years), 16 middle-aged (49±2 years) and 13 older (73±2 years) men.ResultsRepeated measures analysis of variance revealed significant group-by-time interactions for heart rate, central diastolic blood pressure (DBP), central pulse pressure (PP), PP amplification (PPA), central aortic pressure augmentation (AP), aortic augmentation index (AIX), and LVEW. Magnitude of change from baseline was significantly different in the older group compared to young and middle-aged groups in response to exercise at 65% of predicted HRmax for AP (3±1mmHg vs. 7±1, P<0.001 and 3±1mmHg, P<0.001) and LVEW (724±215 dynes s/cm2 min vs. 494±199, P<0.001 and 315±192, P<0.001).ConclusionsThis study suggests that changes in the timing and amplitude of reflected pressure waves during exercise alter the hemodynamic response to exercise with aging. In response to exercise, AP and LVEW increased in older subjects while young and middle-aged subjects exhibited a decline in AP and no change in LVEW. © 2011 American Journal of Hypertension, Ltd.