Relationship between hyperhomocysteinemia and atherosclerosis in chronic hemodialysis patients.

BACKGROUND: Hyperhomocysteinemia is an independent risk factor of coronary artery heart disease (CAHD) and atherosclerosis in a normal population. However, it is still controversial in end-stage kidney disease patients who underwent long-term dialysis. Carotid intima-media thickness (IMT) is the standard non-invasive measurement of atherosclerosis. The aims of the present study were to determine the homocysteine (Hcy) level, and to evaluate its role as a risk factor of atherosclerosis in hemodialysis (HD) patients. MATERIAL AND METHOD: Clinical data and blood chemistries were assayed in 62 HD patients. Atherosclerosis was defined by clinical presentations of CAHD, cerebrovascular or peripheral vascular diseases, or carotid plaque by ultrasound. IMT was also measured by ultrasound RESULTS: Plasma Hcy level in HD patients was significantly higher in HD patients than normal controls (28.3 +/- 8.3 vs 9.7 +/- 2.9 micromol/l, p < 0.001). Older age (p < 0.001), male sex (p = 0.05), longer duration of HD (p = 0.05), and higher plasma Hcy level (p = 0.01) correlated with atherosclerosis by univariate analysis, but plasma Hcy did not show significant correlation by multivariable analysis. There was also correlation between IMT and atherosclerosis in HD patients (p < 0.001) but no correlation was observed between plasma Hcy level and lMT. CONCLUSION: Hyperhomocysteinemia is not an independent factor in the genesis of atherosclerosis in HD patients. Advanced age plays a major role of hyperhomocysteinemia and IMT is a useful marker of atherosclerosis in these patients.

Circulating N-terminal pro-brain natriuretic peptide and cardiac troponin T in chronic dialysis patients.

In the general population, plasma concentrations of cardiac troponin T (cTnT) and N-terminal pro-brain natriuretic peptides (NT-proBNP) are useful as markers of cardiac ischemia and heart failure respectively. Whether these cardiac markers have similar diagnostic potential in chronic dialysis patients are not known. The authors studied the diagnostic value of cTnT and NT-proBNP correlated with the clinical status of 63 chronic renal failure (CRF) patients with chronic dialysis (30 males and 33 females), aged 26 to 77 years (mean +/- SD, 55.9 +/- 12.6 years). Plasma cTnT and NT-proBNP were determined by using Elecsys 2010 (Roche, Switzerland). The authors found that 23.8 per cent of the chronic dialysis patients had cTnT concentrations more than the cut-off (> or = 0.1 ng/ml) and 100 per cent of these patients had NT-proBNP concentrations over the cut-off (> 334 pg/ml). The authors could not demonstrate the statistical difference between males and females for NT-proBNP concentrations as reported in the general population. But cTnT concentrations in females were significantly less than males. The authors also found a weak correlation between the two markers, when the circulating cTnT was correlated with NT-proBNP. These results suggested that plasma cTnT in chronic dialysis patients should be a prognostic marker for cardiac ischemia by using the same cut-off as the normal population. However, plasma NT-proBNP concentrations could not be used as a heart failure marker in this group of patients and needed another cut-off value for specific use in chronic dialysis patients. Moreover, the combination of cTnT and NT-proBNP concentrations in these patients may be another choice for detection of both cardiac ischemia and heart failure in the same situation. These combination markers should improve mortality in chronic dialysis patients.