Abstract
BACKGROUND: To estimate the association of degree of prematurity with arterial stiffness in young adults using augmentation index corrected for a heart rate of 75 beats per minute (AIx@75) and pulse wave velocity (PWV). METHODS: This was a secondary cross-sectional analysis from a prospective cohort study of young adults born preterm with extremely low or very low birth weight (<1,500 g) and term-born peers with normal birth weight. Gestational age at birth was the exposure. Arterial stiffness outcome assessment was performed using radial artery tonometry (Sphygmocor) and a pressure wave transducer with an electrocardiogram (Colin). We used directed acyclic graph-informed multivariable linear regression to estimate the association of gestational age at birth on the continuous and binary scales with AIx@75 and PWV. RESULTS: Of the 113 participants, 110 had AIx data and 97 had PWV data for analysis. AIx@75 was 5.07% higher in the preterm group. In adjusted analysis, each one-week higher gestational age at birth was associated with lower AIx@75 among the entire cohort (-0.38% per week, 95% confidence interval -0.74, -0.02). There was no statistically significant difference in PWV between the preterm and term groups. CONCLUSIONS: There was a higher AIx in young adults with increasing severity of prematurity amongst the entire cohort, but no difference in PWV. More studies are needed that directly assess the severity of prematurity with arterial wall stiffness and alterations in arterial wall structure to determine if they are associated with a higher risk of hypertension and cardiovascular disease long term in the premature population.