Changes in Arterial Stiffness and Wave Reflection With Advancing Age in Healthy Men and Women

With advancing age, arterial stiffness and wave reflections increase and elevate systolic and pulse pressures. An elevated central pulse pressure is generally ascribed to increased wave reflection and portends an unfavorable prognosis. Using arterial tonometry, we evaluated central (carotid-femoral) and peripheral (carotid-brachial) pulse wave velocity, amplitudes of forward and reflected pressure waves, and augmentation index in 188 men and 333 women in the Framingham Heart Study offspring cohort who were free of clinical cardiovascular disease, hypertension, diabetes, smoking within the past 12 months, dyslipidemia, and obesity. In multivariable linear regression models, advancing age was the predominant correlate of higher carotid-femoral pulse wave velocity; other correlates were higher mean arterial pressure, heart rate, and triglycerides and walk test before tonometry (model R2=0.512, P<0.001). A similar model was obtained for carotid-brachial pulse wave velocity (model R2=0.227, P<0.001), although the increase with advancing age was smaller. Owing to different relations of age to central and peripheral stiffness measures, carotid-femoral pulse wave velocity was lower than carotid-brachial pulse wave velocity before age 50 years but exceeded it thereafter, leading to reversal of the normal central-to-peripheral arterial stiffness gradient. In this healthy cohort with a minimal burden of cardiovascular disease risk factors, an age-related increase in aortic stiffness, as compared with peripheral arterial stiffness, was associated with increasing forward wave amplitude and pulse pressure and reversal of the arterial stiffness gradient. This phenomenon may facilitate forward transmission of potentially deleterious pressure pulsations into the periphery.