[The role of hyperhomocysteinemia on atherosclerosis in patients with chronic renal failure]

Abstract

Objective: To determine whether atherosclerosis may be accelerated by hyperhomocysteinemia in patients with chronic renal failure (CRF).

Methods: One hundred and ninety-seven CRF patients and 53 healthy volunteers were included in this study. Plasma total homocysteine (tHcy) levels were measured by using fluorescence polarization immunoassay. Intima-media thickness (IMT) and prevalence atherosclerotic plaques of the extracranial common carotid artery were determined by high-resolution B-mode ultrasonography. The changes in brachial artery diameter during reactive hyperemia (D(h)) and after administration of sublingual nitroglycerin (D(n)) were analyzed during ultrasonic examination.

Results: The prevalence of hyperhomocysteinemia was 84.4% in the CRF patients. The mean level of tHcy (23.56 +/- 11.91) micro mol/L was significantly higher in the CRF patients than that in the healthy controls (7.97 +/- 2.65) micro mol/L (P < 0.01). The prevalence of atherosclerotic plaques and the mean IMT value of carotid artery were significantly increased in CRF patients compared with that in age-matched controls. Furthermore, arterial dilating function sush as D(h) and D(n) was significantly decreased in CRF patients [(D(h)) (4.05 +/- 3.81)% and (D(n)) (4.94 +/- 4.28)%] compared with that in controls [(D(h)) (8.81 +/- 6.15)% and (D(n)) (11.72 +/- 7.64)%] (P < 0.01). The levels of plasma tHcy were coherent with intensity of atherosclerosis in the CRF patients. Multiple stepwise regression analysis showed that in CRF patients, independent risk factors associated with value of IMT were level of tHcy, age, and duration of dialysis (RR = 0.484, P < 0.001), while those associated with D(h) arterial dilatation were plasma tHcy level, age, duration of dialysis and total cholesterol (RR = 0.263, P < 0.001) and those associated with D(n) were age and tHcy level (RR = 0.211, P < 0.001).

Conclusion: The results indicate that atherosclerosis and dysfunction of arterial vasodilation in CRF patients are associated with increase of plasma tHcy. Hyperhomocysteinemia may be an independent risk factor for atherosclerosis seen in CRF patients.