Pulse pressure amplification during exercise is significantly reduced with age and hypercholesterolemia
Sharman, JE and McEniery, CM and Dhakam, ZR and Coombes, JS and Wilkinson, IB and Cockcroft, JR, Pulse pressure amplification during exercise is significantly reduced with age and hypercholesterolemia, Journal of Hypertension, 25, (6) pp. 1249-1254. ISSN 0263-6352 (2007) [Refereed Article]
OBJECTIVES: Exercise brachial blood pressure (BP) is predictive of cardiovascular events. As a result of the amplification of pulse pressure, central BP (a stronger cardiovascular risk factor) differs significantly from peripheral measures. Pulse pressure amplification is reduced with increasing age and hypercholesterolemia at rest, but the effect of exercise on central pressure in these populations is unknown. This study aimed to assess the central and peripheral BP response to exercise with aging and hypercholesterolemia. METHODS: Twenty healthy younger (aged 29 ± 5 years; mean ± SD), 20 healthy older (aged 57 ± 5 years) and 12 matched older (aged 59 ± 7 years) men with hypercholesterolemia exercised (bicycle ergometer) at 60% of their predicted maximal heart rate. Central BP and augmentation index (AIx), a marker of systemic arterial stiffness, were obtained non-invasively using pulse wave analysis. Pulse pressure amplification was defined as the ratio of peripheral to central pulse pressure. RESULTS: The resting haemodynamics of the older men were not significantly different from those with hypercholesterolemia. During exercise, amplification was significantly lower (P < 0.001), and the augmentation index significantly higher (P < 0.001) in the hypercholesterolemic individuals. Younger men had significantly increased amplification (P < 0.01) and reduced AIx (P < 0.001) at rest and during exercise compared with older men. In multiple regression analysis, exercise pulse pressure amplification was independently predicted by age (â = -0.48; P < 0.001) and total cholesterol (â = -0.28; P = 0.03). CONCLUSION: With increasing age, exercise pulse pressure amplification is significantly attenuated because of increased wave reflection. These effects are exacerbated by hypercholesterolemia and may contribute to cardiovascular risk by mechanisms associated with central hypertension.