Endothelium-dependent vasodilatation and distensibility of large arteries in chronic haemodialysis patients.

BACKGROUND

Cardiovascular mortality is increased in chronic haemodialysis (HD) patients and is not completely explained by common cardiovascular risk factors. Hyperhomocysteinaemia and chronic HD per se may play a role, because these factors may adversely affect endothelial function and distensibility of conduit arteries, which are important determinants of the risk of atherosclerosis, thrombosis and cardiac hypertrophy.

METHODS

A vessel wall movement detector system was used to investigate endothelium-dependent, flow-mediated and endothelium-independent, glyceryl trinitrate-induced vasodilatation in the brachial artery and compliance and distensibility coefficients (CC and DC) in the common carotid artery in 28 chronic HD patients and 28 control subjects.

RESULTS

Endothelium-dependent, but not endothelium-independent, vasodilatation was markedly reduced in the HD group (3.7 +/- 1.1 vs. 9.7 +/- 1.2%; P = 0.001). The DC was reduced only in a subgroup of patients aged < 50 years: 16.9 +/- 1.5 vs. 22.4 +/- 2.0 10(-3)/kPa (P = 0.032) and was not related to endothelium-dependent vasodilatation. CC did not differ between the groups. Plasma total homocysteine was elevated in the HD patients, but was neither related to endothelium-dependent vasodilatation, nor to DC.

CONCLUSION

Chronic renal failure and (or) chronic haemodialysis are associated with impaired endothelium-dependent vasodilatation, which may reflect an increased susceptibility for the development of atherosclerosis and thrombosis.