Association between Hyperhomocysteinemia and Ultrasonographic Atherosclerotic Indices of Carotid Arteries in Chronic Hemodialysis Patients

Abstract

Background: Atherosclerotic cardiovascular events are a major cause of morbidity and the main cause of mortality in hemodialysis patients. Hyperhomocysteinemia – which is a consistent finding in uremic patients – is considered an independent risk factor for cardiovascular disease (CVD). However, the relationship between plasma homocysteine (Hcy) concentrations and atherosclerotic CVD has not been extensively investigated. Patients and Methods: 37 patients undergoing chronic hemodialysis and 30 healthy individuals (control group), sex- and age-matched, were included in this study. Both healthy controls and hemodialysis patients underwent echo-Doppler carotid artery examination. The right and left carotid arteries were assessed separately. Our observation included measurements of the ultrasound images of the intimal wall thickness, the lumen diameter and the atherosclerotic plaques. We determined plasma Hcy, vitamin B₁₂ and folic acid levels and serum cholesterol, triglycerides, HDL, ApoA-I, ApoB-100, Lp(a), CRP, albumin and creatinine levels in blood samples from both studied groups. We also determined the urea reduction ratio in the patient groups. The epidemiological as well as the biochemical data were correlated with the findings of the carotid artery examination. Results: Plasma Hcy levels were significantly increased in hemodialysis patients compared to controls (33 ± 12.3 vs. 12.27 ± 7.47 µmol/l, p < 0.001). Intimal wall thickness, lumen diameter and number of atherosclerotic plaques of both carotid arteries were significantly higher (p < 0.01 or p < 0.001) in patients compared to controls. There was a significant positive correlation between plasma Hcy levels and the number of the atherosclerotic plaques (r = 0.41, p < 0.01 in the right and r = 0.49, p < 0.001 in the left carotid artery). Lumen diameter was significantly (p < 0.01) associated with age, MAP and CRP levels. Significant correlations (p = 0.05–0.01) were also found between the number of the plaques and age as well as the duration of hemodialysis, while folic acid levels were inversely correlated with the number of the plaques. Conclusions: Both hyperhomocysteinemia and atherosclerotic indices of the carotid arteries are more prevalent in hemodialysis patients compared to healthy controls. Elevated plasma Hcy levels were associated with the carotid artery atherosclerotic indices in chronic hemodialysis patients.