Homocystein and carotid atherosclerosis in chronic renal failure

Since total homocysteine (Hcy) is markedly elevated in patients with chronic renal failure (CRF), it has been presented as potential factor contributing to the high risk of cardiovascular disease (CVD) in CRF. The aim of the study was to examine the significance of elevated Hcy and other cardiovascular risk factors for carotid atherosclerosis in patients with CRF.

Fifty six patients 16-M, 40-F, average age 58+/-14.55, creatinine clearance 39.19+/-10.11 ml/min were examined. In addition, 20 control healthy subjects were examined. The association of Hcy levels and classic risk factors for atherosclerosis with common carotid intima-media thickness (IMT) was examined. B-mode ultrasound measurement of carotid IMT was performed in 56 hypertensive pts with CRF (glomerular filtration rate>20 ml/min and <90 ml/min), 44 hypertensive pts with normal renal function and 20 healthy volunteers. The mean duration of hypertension was 145.12 years.

IMT in all examined hypertensive pts was increased above normal clinical value and significantly higher then in healthy controls (0.75+/-0.006/0.60+/-0.1, p<0.001). The carotid IMT was similar between hypertensive pts with CRF and hypertensive pts with normal renal function (0.74+/-0.1/0.76 +/-0.1, p>0.05). Significant predictors for IMT were age (r=0.358, p<0.04), duration of hypertension (r=0.395, p=0.023), diabetes duration (r=0.343, p<0.02), as well as duration of CRF (r=0.324, p<0.006). There was a negative correlation between IMT and glomerular filtration rate assessed by creatinine clearance (r=-0.303, p<0.003). Renal function, described by creatinine clearance was the strongest determinant for Hcy levels (r=-0.332, p<0.008). Increased IMT was estimated in pts with CRF compared to healthy controls (0.74+/-0.10 vs 0.59+/-0.10, p<0.001). We found association between Hcy and carotid IMT ( r=0.344, p<0.015). No consistent association was found between IMT and other specific for CRF cardiovascular risk factors.

The study suggests that patients with mild renal failure have increased IMT of the common carotid artery and that elevated plasma Hcy level in CRF is associated with carotid intima- media thickening.