P-483: Reduction in aortic compliance in adolescents with suboptimal intrauterine growth

Objective: To study the impact of birth weight (BW) on indirect measurements of aortic compliance: office and ambulatory pulse pressure (PP) and augmentation index (AI). Subjects and Methods: Three hundred and sixteen subjects (185 girls), age from 10 to 18 years, and BW ranging from 2 to 4.8 kg were included. Ambulatory BP was assessed (Spacelabs 90217) during a 24-hour period. In a subgroup of seventy-one subjects (BW 3.5 kg, n= 34) the AI was measured by tonometry (ORourke method). The radial artery pressure waveform data were processed by the SphygmoCor radial/aortic transform software module to produce the estimated aortic pressure waveform. The extent of wave reflection was estimated by the AI defined two ways: as the amount and as the ratio of the amplitude of pressure wave above its systolic shoulder to the pulse pressure. Results: Children in the lowest BW had the highest office and ambulatory PP. In a multiple regression model current weight (p