Endothelial dysfunction marker von Willebrand factor antigen in haemodialysis patients: Associations with pre-dialysis blood pressure and acute phase response

Abstract

Background. Increased plasma soluble von Willebrand factor antigen (vWF: Ag) level, a marker of vascular endothelial cell dysfunction, is a strong predictor of atherosclerotic cardiovascular disease (CVD) in the general population. We studied cross-sectional associations between vWF: Ag level, prevalence of CVD, and related factors including pre-dialysis arterial blood pressure (BP) and some markers of inflammation in maintenance haemodialysis (HD) patients. Methods and results. Plasma vWF: Ag level measured by an enzyme-linked immunosorbent assay (ELISA) was higher in 110 HD patients than in 20 controls. On bivariate regression analysis, vWF: Ag level was directly associated with the presence of CVD, age, fibrinogen and the use of enoxaparin (vs unfractionated heparin) during HD procedures, and inversely with albumin and pre-dialysis BP. The patients with prevalent CVD were older, had higher vWF: Ag, white blood cell and platelet counts, fibrinogen and triglycerides, lower albumin levels, and were less frequently on combination antihypertensive therapy. Multi-variable analyses identified low pre-dialysis BP, hypoalbuminaemia and hyperfibrinogenaemia (in descending order of significance) as independent predictors of high vWF: Ag level. There were no associations between vWF: Ag levels and gender, ABO blood type, smoking, body mass index, renal failure cause, duration of HD therapy, Kt/V, normalized protein catabolic rate, dialysate buffers, dialysers, viral hepatitis, erythropoietin treatment, specific antihypertensive drugs, haemoglobin, white blood cell and platelet counts, liver enzymes, phosphorous, total cholesterol, and triglycerides. Conclusion. Elevated plasma levels of endothelial dysfunction marker vWF: Ag in maintenance HD patients are associated with established cardiovascular mortality risk factors such as low pre-dialysis blood pressure and the activated acute phase response.