Effects ofAgeandAerobic Capacit on Arterial Stiffness inHealthy Adults

Background. Ithasbeenwell established that arterial stiffness, manifest as an increase inarterial pulse wave velocity or latesystolic amplification ofthecarotid artery pressurepulse, increases withage. However, thepopulations studied inpriorinvestigations were notrigorously screened toexclude clinical hypertension, occult coronarydisease, ordiabetes. Furthermore, itisunknownwhether exercise capacity orchronic physical endurance training affects theage-associated increase inarterial stiffness. Methods andResults. Carotid arterial pressurepulse augmentation index(AGI), usingapplanation tonometry, andaortic pulse wavevelocity (APWV)weremeasured in146maleandfemale volunteers 21 to96yearsoldfromtheBaltimore Longitudinal Study ofAging, whowererigorously screened toexclude clinical andoccult cardiovascular disease. Aerobic capacity was determined inallindividuals by measurement ofmaximal oxygenconsumption (Vo2m.) during treadmill exercise. Inthis healthy, largely sedentary cohort, thearterial stiffness indexes AGIandAPWV increased approximately fivefold and twofold, respectively, acrosstheagespaninboth men andwomen, despite onlya 14%increase insystolic blood pressure(SBP). Theseage-associated increases inAGIandAPWV wereofa similar magnitude to those inprior studies ofless rigorously screened populations. BothAGIandAPWV varied inversely with Vo2.,,,, andthis relationship, atleast forAGI, wasindependent ofage.Inendurance trained maleathletes, 54to75yearsold(V02,_=44+-3 mL.kg`*min'),thearterial stiffness indexes were significantly reduced relative totheir sedentary agepeers(AGI, 36%lower, APWV,26%lower) despite similar blood pressures. Conclusions. Eveninnormotensive, rigorously screened volunteers inwhomSBPincreased an averageof only14% between ages20and90years., majorage-associated increases ofarterial stiffness occur.Higher physical conditioning status, indexed byVo2.,wasassociated withreduced arterial stiffness, bothwithin this predominantly sedentary population andinendurance trained older men relative totheir less active agepeers. These findings suggest that interventions toimprove aerobic capacity may mitigate thestiffening ofthearterial tree thataccompanies normative aging. (Ciclation. 1993;88[part 11:1456-1462.)