DIFFERENT EFFECTS OF AGING ON ELASTIC AND MUSCULAR ARTERIAL BIFURCATIONS IN MEN

In a previous study we have shown that the wall of the elastic carotid artery bifurcation (CAB) stiffens inhomogeneously with increasing age , the carotid artery bulb being most affected. In the present study th e effect of ageing on the elastic properties of the wall and the strai n the wall is exposed to along the muscular femoral artery bifurcation (FAB) was investigated using the CAB for comparison. The study was pe rformed with 10 young (aged 20-30 years) and 10 old (50-60 years) pres umed healthy volunteers. Distensibility along the bifurcation was dete rmined by measuring noninvasively the maximum relative diameter change s of-the artery during systole (peak Delta d/d . 100%), which is also a measure of strain, at various sites along both bifurcations by means of a vessel wall moving detector system. This system also makes the a ssessment of (end-diastolic) diameter possible. At all levels along th e CAB, the diameter was significantly larger in the old than in the yo ung. In the FAB, the diameter was only significantly larger in the old than in the young in the common and superficial femoral arteries. At all levels in the CAB, peak Delta d/d . 100% was significantly lower i n the old than in the young, the carotid artery bulb being more affect ed than the common carotid artery (CCA), while in the FAB this paramet er was lower in the old than in the young only in the common femoral a rtery (CFA). Peak Delta d/d . 100% was similar in the CCA and in the b ulb in the young, but significantly higher in the CCA than at all leve ls in the bulb in the old. In the FAB, in the young peak Delta d/d . 1 00% was significantly higher in the CFA than at both levels in the dee p and superficial femoral arteries, while in the old no significant di fferences in peak Delta d/d . 100% along the FAB could be detected. Th ese findings indicate that the loss of wall elasticity with increasing age is different in the muscular and elastic arterial bifurcations in vestigated. The homogeneous distribution of wall elasticity in the ela stic CAB at a younger age becomes inhomogeneous at an older age, while the opposite is observed in the muscular FAB. The changes in strain t he different parts of the bifurcations are exposed to with increasing age are different in the CAB and the FAB. Differences in distensibilit y along bifurcations will make them deform inhomogeneously during the cardiac cycle.