Age-related changes in total arterial capacitance from birth to maturity in a normotensive population.
We evaluated the effect of body growth and aging on the ratio of echocardiographic (Teichholz) stroke volume to pulse pressure (SV/PP ratio) in 373 normal-weight, normotensive children to adolescents (1 day to 17 years old; 166 girls, 87 nonwhite) and 393 normal adults (17 to 85 years old; 164 women, 112 nonwhite). Stroke volume increased with age in children (r = .64, P < .0001) and was stable in adults; pulse pressure decreased slightly with age in children (r = -.10, P = .06) and increased in adults (r = .29, P < .0001). As a consequence, SV/PP ratio increased with age in children (r = .51, P < .0001) and decreased in adults (r = -.18, P = .0004). To control for changes in body size that influence the size of the arterial tree, we used ANCOVA to adjust SV/PP for body size. Body size-adjusted SV/PP ratio was no longer related to age in children, whereas the negative relation with aging in adults remained statistically significant (r = -.19, P < .0002). Heart rate was negatively related to SV/PP ratio in both children and adolescents and adults, but this relation did not influence the relation with age. In multivariate analysis, high SV/PP ratio was predicted by greater height (P < .002) and weight (P < .04) and nonwhite race (P < .001) in children and adolescents and by younger age (P < .0001), greater weight (P < .0001), and low heart rate (P < .001) in adults. Sex did not enter the regression models. Thus, (1) SV/PP ratio is a measure of increasing capacity of the arterial tree during growth, whereas it depends on arterial compliance during adulthood through old age; (2) arterial compliance decreases progressively with aging; (3) the apparent difference between males and females might be due to their different body sizes.
de Simone
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Division of Cardiology, New York Hospital-Cornell Medical Center, New York 10021, USA. mjograd@mail.med.cornell.edu
Roman
M J
MJ
Daniels
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Mureddu
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Kimball
T R
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Greco
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Devereux
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D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001158:Arteries / Q000502:physiology*; D001794:Blood Pressure; D001824:Body Constitution; D002648:Child; D002675:Child, Preschool; D003187:Compliance; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D013318:Stroke Volume