Effects of Hemodialysis on Brachial Artery Endothelial Function

OBJECTIVES: The purposes of this study were to determine brachial artery endothelial function in patients at varying times during hemodialysis and to evaluate the influence and time-dependent effects of hemodialysis on the vascular endothelium. METHODS: The brachial artery systolic and diastolic dimensions and diameter after reactive hyperemia in patients undergoing hemodialysis (dialysis group), uremic patients who had not yet undergone hemodialysis (predialysis group), and healthy volunteers (control group) were measured by high-frequency sonography. The distensibility coefficient, degree of brachial artery stiffness, and flow-mediated dilatation were calculated. RESULTS: The distensibility coefficient and flow-mediated dilatation of the brachial artery were significantly decreased, whereas the degree of stiffness was significantly increased, in the dialysis and predialysis groups compared with the control group (P < .01). There were no significant differences in these parameters between the dialysis group at 12 months and the predialysis group (P> .05). The distensibility coefficient and flow-mediated dilatation at 36 months were significantly lower (P < .01), whereas the degree of stiffness was significantly higher, than that at 12 months after starting hemodialysis (P < .01) but not between 36 and 60 months after hemodialysis (P > .05). CONCLUSIONS: Hemodialysis could aggravate endothelial dysfunction in uremic patients and this effect is associated with the duration of hemodialysis.