Acute effect of haemodialysis on arterial stiffness: membrane bioincompatibility?
BACKGROUND
Repetitive endothelial damage from dialysis membrane incompatibility is a probable cause of accelerated atherosclerosis in haemodialysis patients. Consequently pulse wave velocity (PWV), a measure of arterial stiffness, was utilized as a surrogate marker of vascular dysfunction during dialysis with two commonly used synthetic dialysers.


METHODS
PWV was monitored before, during and after haemodialysis using both polysulphone and polyamide membranes. PWV, an arterial stiffness measure, was calculated from the carotid to the femoral (C-F) and also to the radial (C-R) artery. In a further group, PWV was monitored while polysulphone and polyamide membranes were perfused with blood without dialysate.


RESULTS
Mean aortic (C-F) PWV was lower during dialysis with the polyamide membrane, being 14 and 16% less following 75 and 135 min of dialysis (P<0.05) in 24 patients. Because intradialytic intravascular volume changes alter PWV, a subgroup analysis in 11 patients where dialysis fluid removal during both periods was minimal (<1 kg) was performed, and a persistent and significant increase in aortic PWV was detected with the polysulphone kidney being maximal (40%) at 75 min (P<0.01). This increase was negatively correlated with pre-dialysis PWV (P<0.01). In contrast, the polyamide dialyser did not change PWV. An increase in C-R PWV was also noted with the polysulphone membrane (P<0.05). In the nine patients where membranes were perfused with blood without dialysate, aortic PWV was again significantly increased by the polysulphone (P<0.01), but not the polyamide dialyser.


CONCLUSIONS
Haemodialysis with polysulphone but not polyamide membranes acutely alters aortic 'stiffness', an effect postulated to be due to membrane bioincompatibility. However, factors including age, time on dialysis and underlying vascular disease, were also found to impact on these acute dialysis-induced changes to vascular function. Since these acute changes disappear post-dialysis, their long-term consequences are uncertain.
Mourad
Adnan
A
Department of Nephrology, John Hunter Hospital, Locked Bag 1, Hunter Region Mail Centre, NSW 2310, Australia.
Carney
Shane
S
Gillies
Alastair
A
Jones
Bernard
B
Nanra
Ranjit
R
Trevillian
Paul
P
D000328:Adult; D000368:Aged; D001166:Arteriovenous Shunt, Surgical; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D005263:Femoral Artery; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D009757:Nylons; D018384:Oxidative Stress / Q000502:physiology; D011108:Polymers; D017534:Radial Artery; D006435:Renal Dialysis / Q000009:adverse effects; D013450:Sulfones
D001672:Biocompatible Materials; D008567:Membranes, Artificial; D009757:Nylons; D011108:Polymers; D013450:Sulfones; C017662:polysulfone P 1700