Arterial stiffness and functional properties in chronic kidney disease patients on different dialysis modalities: an exploratory study.
BACKGROUND
Abnormalities of vascular function and accumulation of oxidative stress have been associated with chronic kidney disease (CKD). Dialysis modalities, peritoneal dialysis (PD) and haemodialysis (HD) may differentially impact on vascular function and oxidative stress.


METHODS
Patients undergoing living donor transplantation were studied for vascular stiffness using pulse wave velocity measurements, and inferior epigastric arteries were harvested to examine in vitro stiffness and functional properties and evidence of oxidative stress. Forty-one patients were studied representing PD (n = 12), HD (n = 14) and non-dialysed recipients (n = 15).


RESULTS
We demonstrated differences in stiffness from in vivo and in vitro measurements such that non-dialysis < HD < PD groups. The stiffness measurements did not correlate with duration of CKD nor dialysis duration, but did so with phosphate levels (r = 0.356, P = 0.02). From the in vitro isometric force experiments, HD arteries demonstrated decreased contractility and endothelium-dependent relaxation compared with PD and non-dialysis vessels. Level of oxidative stress (as indicated by the 8-isoprostane level) was 30% higher in HD arteries than in PD arteries. Protein expression of inducible nitric oxide synthase, NADPH subunits and xanthine oxidase was upregulated in HD arteries, while superoxide dismutase was downregulated. The compromised vascular function in HD arteries was improved by pharmacological means that eliminated oxidative stress.


CONCLUSIONS
We report associations between vasomotor function and oxidative stress in the vasculature of patients receiving different dialysis therapies. Oxidative stress, which may be differentially augmented during PD and HD, may play an important role in the vascular dysfunction in dialysis populations.
Chung
Ada W Y
AW
Department of Cardiovascular Science, Child and Family Research Institute, University of British Columbia, Vancouver, Canada. achung0129@hotmail.com
Yang
H H Clarice
HH
Kim
Jong Moo
JM
Sigrist
Mhairi K
MK
Brin
Genevieve
G
Chum
Elliott
E
Gourlay
William A
WA
Levin
Adeera
A
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D002908:Chronic Disease; D004548:Elasticity / Q000502:physiology*; D019074:Epigastric Arteries / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000503:physiopathology* / Q000601:surgery / Q000628:therapy*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D010530:Peritoneal Dialysis / Q000379:methods*; D006435:Renal Dialysis / Q000379:methods*; D014661:Vasoconstriction / Q000502:physiology; D014666:Vasomotor System / Q000502:physiology