Vasculopathy in Turner Syndrome: Arterial Dilatation and Intimal Thickening without Endothelial Dysfunction
JE Ostberg1, AE Donald2, C Storry2, C McCarthy1, JP Halcox2 & GS Conway1
Dissection or rupture of the aorta accounts for death in 2-8% of women with Turner Syndrome (TS), and dilatation of the aortic root, has been reported as a predisposing factor. We compared measures of arterial structure, stiffness and endothelial function to investigate whether women with TS have a fundamental arterial wall defect which extends beyond the arch of the aorta. Local Ethics Committee approval was obtained.
Age-matched women with TS (n=93), 46,XX gonadal dysgenesis(GD) (to control for oestrogen-deficiency in TS) (n=11), and normal controls (n=25) underwent vascular physiology assessments: internal carotid and brachial artery diameters, internal carotid intima-media thickness(IMT), pulse wave velocity(PWV) and augmentation index(AIx), flow-mediated dilatation(FMD). Women with TS also had echocardiography to assess aortic root diameter(ARD).
TS women had greater absolute dimensions of carotid (5.71 vs 5.22 vs 5.27 mm,p<0.001) and brachial (3.29 vs 2.97 vs 3.06mm,p<0.01) arteries than 46,XXGD and normal controls respectively. Height adjustment strengthened this relationship. Within the TS cohort, ARD, carotid and brachial diameters were intercorrelated (p</=0.05 for all). Carotid diameter was independently associated with height (r=0.393,p<0.001), waist (r=0.184,p<0.05) and IMT (r=0.217,p<0.05) but not bicuspid aortic valve.
IMT was similar in the TS and 46,XX GD groups and greater than in normal control women (0.61 vs 0.60 vs 0.55mm for the three groups respectively, p<0.001). IMT associations in TS were oestrogen-deficient years (r=0.249,p<0.01) and, independently, age (r=0.273,p<0.001), blood pressure (r=0.335,p<0.001) and carotid artery diameter (r=0.192,p<0.05).
Absolute but not height-adjusted AIx was greater in TS than the other groups, but there was no difference in PWV or FMD.
Women with TS appear to have widespread arterial dilatation, even when height-adjusted, and intima media thickening. The latter is associated with oestrogen deficiency, reflected by the similarity with 46,XXGD women. Arterial stiffness and endothelial function do not appear to be important components of the vasculopathy in TS.