Impact of Aging on Central Pressure Wave Reflection During Exercise

Abstract

PURPOSE: Age is associated with increases in arterial stiffness and pulse wave velocity, which cause profound changes in arterial pressure waves, including increases in augmented pressure (AG), augmentation index (AIx) and wasted left ventricular energy. We examined the impact of aging on the central blood pressure (BP) waveform and wave reflection responses during light and moderate upright bicycle exercise. METHODS: Sixteen older (48 ± 2 yr) and 14 younger (24 ± 1 yr) men were recruited for this study. Central blood pressure and wave reflection characteristics were measured non-invasively using applanation tonometry at rest and during cycling exercise (45-65% of age predicted maximal heart rate). RESULTS: Older men had increased central pressures and AIx (26 ± 2 vs. 12 ± 2 %) and lower pulse pressure amplification (PPA; 1.29 ± 0.03 vs. 1.50 ± 0.04) than their younger counterparts at rest (P < 0.05). Central pressures and AIx (10 ± 3 vs. −8 ± 3 %) continued to be greater, while PPA (1.61 ± 0.04 vs. 1.85 ± 0.03) was lower in the older group compared to the younger group during moderate intensity exercise (P < 0.05). However, the relative changes from baseline for central pressures, AIx (−15 ± 2 vs. −19 ± 3), and PPA (0.32 ± 0.03 vs. 0.35 ± 0.04) were similar for both groups (P > 0.05). CONCLUSIONS: The findings of the present study suggest that older men have a greater central BP and AIx and lower PPA during light and moderate levels of exercise. However, the magnitude of the central hemodynamic responses (i.e. change from baseline) during exercise do not differ between older and younger men.