Are changes in conduit artery function associated with intima-medial thickness in young subjects?

BACKGROUND: Impaired brachial artery endothelial function, assessed by flow-mediated dilation (FMD), provides a strong prognostic index of cardiovascular events in asymptomatic adults and those with cardiovascular disease. However, the relationship between FMD and carotid intima-medial thickness (cIMT) in young people is unknown. We hypothesized that impaired FMD, and decreased FMD over time, would predict cIMT. DESIGN AND METHODS: FMD and cIMT were assessed using high-resolution Doppler ultrasound in 53 children (18 boys) aged 10.3 ± 0.3 years. FMD was assessed at baseline and 4-month and 30-month follow up. cIMT was assessed at 30-months. RESULTS: There was no significant relationship between FMD measured at baseline (10.7 ± 4.3) and cIMT at 30 months. FMD was depressed at 4 months (7.2 ± 3.5, p < 0.05) and 30 months (8.2 ± 3.3, p = 0.51). However, there was no correlation between changes in FMD and cIMT. CONCLUSION: Changes in arterial function occurred in young subjects across a 30-month time frame; however, these changes were unrelated to individual differences in cIMT in this cohort. These data contrast with findings in adults and indicate that longer periods of functional impairment may be necessary before atherosclerotic wall thickening becomes apparent in young people, suggesting there is a 'window of opportunity' for preventative intervention strategies.