Impaired endothelium-dependent vasodilatation in renal failure in humans

Background. The main causes of death in patients with chronic renal failure (CRF) are cardiovascular complications. The aim of the present study was to compare endothelium-dependent vasodilatation (EDV) in patients with chronic renal failure with a control population controlling for hypertension, diabetes mellitus and hypercholesterolaemia. Methods. Fifty-six patients with moderate CRF (mean creatinine clearance 29.4 ml/min/1.73 m(2)) underwent evaluation of EDV and endothelium-independent vasodilatation (EIDV) by means of forearm blood flow (FBF) measurements with venous occlusion plethysmography during local intra-arterial infusions of methacholine (Mch, 2 and 4 mug/min evaluating EDV) and sodium nitroprusside (SNP, 5 and 10 mug/min evaluating EIDV). Fifty-six control subjects without renal impairment underwent the same investigation. Results. Infusion of Mch increased FBF significantly less in patients with renal failure than in controls (198 vs 374%, P < 0.001), whereas no significant difference was seen regarding the vasodilatation induced by SNP (278 vs 269%). The differences in EDV between the groups were still significant after controlling for hypertension, blood glucose, and serum cholesterol in multiple regression analysis (P < 0.001). EDV was related to serum creatinine (r = -0.37, P < 0.01), creatinine clearance (r = 0.45, P < 0.005) and to serum triglyceride levels (r = -0.29, P < 0.005) in the CRF group. Conclusions. Patients with moderate CRF have an impaired EDV even after correction fur traditional cardiovascular risk factors and this impairment is related to the degree of renal failure.