Familial aggregation of carotid artery intima media thickness : a three-generation study

Objective: to investigate whether familial aggregation of carotid IMT is influenced by the subjects’ age. Methods: Twenty-four grandchildren (14 men and 10 women), one of their parents (13 men and 11 women) and one of their grandparents (6 men and 18 women), were recruited. Each of them had their CC-IMTmean, Bif-IMTmean, ICA-IMTmean and Mean-IMT measured by B-Mode ultrasound. Simple linear regression analysis by the least squares method was used to investigate correlations between carotid IMT in the young generational pairs (grandchildren vs parents) as well as in the old generational pairs (parents vs grandparents). For each generational pairs, the squared correlation coefficient (r2) was used to evaluate the extent of offspring’s carotid IMT variability explained by the carotid IMT of their respective parents. Results: The mean age (±SD) of grandparents, parents and grandchildren was 77.3±6.8, 51.5±7.4 and 23.5±7.0, respectively. The corresponding figures for Mean-IMT was 1.45±0.25 mm, 0.94±0.22 mm and 0.63±0.10 mm, respectively. Mean carotid IMT variables of progenitors’ correlated with carotid IMT of their offspring in the young generational pairs (r2 =0.24, p<0.015 for Mean-IMT; r2 =0.33, p=0.003 for Bif-IMTmean) but not in the old generational pairs. Conclusions: Familial aggregation of carotid IMT is better appreciable in the young generational pairs. This may be due to the higher prevalence of potential confounding environmental factors in the older generational pairs. Funding: Research supported in part by Italian Ministry of Health.