Cardiovascular risk factors and non-invasive assessment of subclinical atherosclerosis in youth.

Unlabelled: Our understanding of the natural history of atherosclerosis in childhood and its response to cardiovascular (CV) risk factor reduction have been hampered by the lack of a reliable, non-invasive measure of atherosclerosis. Carotid intima media thickness (IMT), a surrogate marker of atherosclerosis in adults, is increased in youth heterozygous for familial hypercholesterolemia (FH) and declines with lipid lowering pharmacotherapy. The age at which vascular changes can be reliably identified using IMT and the influence of CV risk factors beyond FH on IMT remains unclear.

Objective: To examine the influence of demographic, family history, anthropometric characteristics and traditional CV risk factors on IMT in children 5-16 years of age (mean age 11 year).

Methods: In a cross-sectional study, we assessed IMT in 148 children (51 with elevated low density lipoprotein (LDL)-cholesterol, 44 with overweight and 53 controls). Measures included: family history of premature coronary heart disease (CHD), physical activity, pubertal stage, smoking history, fasting glucose, insulin, lipid profile, apolipoproteins A1 and B, anthropometry, blood pressure and IMT.

Results: The groups were similar for age and family history of premature CHD. Compared to controls, average maximum IMT (0.403+/-0.04 vs 0.387+/-0.029) and average mean IMT were elevated in the hyperlipidemia group (p<0.05), but not in the overweight group (max IMT 0.393+/-0.034; p vs control=0.17). Using multiple regression modelling, age, family history of premature CHD and apoliprotein A1 and B predicted 17% of the variability in IMT. No measure of adiposity predicted IMT.

Conclusion: Age is an important predictor of IMT in youth. Among traditional CV risk factors, dyslipidemia and family history of premature CHD are independent predictors of IMT.