Background and purpose: Genetic and environment factors have been linked to the cause of atherosclerosis. Carotid and femoral intima media thickness (IMT) is a marker of early atherosclerosis that is correlated with traditional risk factors and is predictive of subsequent myocardial infarction and stroke. Furthermore, possible differences in the pathophysiology of common carotid artery IMT and femoral IMT might allow the exploration of differential gene regulation in specific vascular beds.

Methods: The current data included 63 probands (mean age 44.83 ± 7.41) and 77 relatives (mean age 45.35 ± 8.14). from 63 families. B-mode carotid and femoral ultrasonography was used to definite mean IMT of commom carotid (CCA) and common femoral artery (CFA). Variance component methods were used to estimate heritability from the normalized deviates.

Results: Variances explained by all final covariates (includes sex, age, blood pressure, smoking, total cholesterol, HDL cholesterol, triglicerides, diabetus status, body mass index) for mean CCA and mean CFA IMT were 0.393 and 0.394, respectively. Multivariable –adjusted heritability were 0.232 for mean CCA and 0.141 for mean CFA IMT (all P <0.005).

Conclusion: These data suggest that genetic factors independent of traditional cardiovascular risk factors more influence to CCA IMT than to CFA IMT. Although we found that acquired risk factors contribute progressively to IMT. Future studies of genetic linkage and gene candidate association are warranted to identify specific genetic variants predisposing early symptoms of atherosclerosis in specific vascular beds.