Measurement of Aortic Intimal-Medial Thickness in Adolescents and Young Adults

Atherosclerosis begins in childhood in the distal abdominal aorta and later involves the carotid arteries. Noninvasive screening to detect these lesions may allow early intervention. Ultrasound images of the distal 10 mm of the aorta were obtained after an 8-h fast and were analyzed by an automated program to determine the mean far wall intimal-medial thickness (IMT). The results were compared with the mean carotid IMT obtained concurrently. The mean age of the 313 males and 322 females imaged was 20.4 years (SD 5.6) and 61 participants had a second study to assess reproducibility. The mean aortic IMT was 0.63 mm (SD 0.14) for males and 0.61 mm (SD 0.13) for females while the mean carotid IMT was 0.50 (SD 0.04) mm and 0.49 (SD 0.04) mm, respectively. Images were analyzed in 95% of participants. Intra-subject reproducibility for the mean aortic IMT had a coefficient of variation of 18% with a mean absolute difference of 0.12 mm (SD 0.10). For carotid IMT, the results were 3% and 0.02 mm (SD 0.01), respectively. Aortic IMT can be measured in normal adolescents and young adults with low rates of missing data and reasonable reproducibility. Aortic IMT increased with age at a greater rate than carotid IMT. (E-mail: pat-davis@uiowa.edu)