Relationship of Homocystine and Related Cofactors Levels to Cardiac Changes in children with Chronic Renal Failure

ABSTRACT
Background: Patients with chronic renal failure (CRF) exhibit an abnormally high incidence of cardiovascular diseases usually due to cardiomyopathy and ischemic heart disease. A high frequency of hyperhomocysteinemia has been demonstrated in children with chronic renal failure. Reasons are: Decreased renal clearance, accumulation of toxic metabolites, inhibition of homocysteine (HCy) metabolism and a decrease in serum level of vitamin B12 and folic acid which are necessary for HCy metabolism. Hyperhomocysteinemia is recognized as an independent risk factor for cardiovascular disease, especially atherosclerosis in adult patients with CRF. However, there is little information about the relationship between plasma homocysteine levels and cardiac diseases in children with CRF. Objectives: The aim of this study was to determine relation between plasma homocysteine, folic acid, vitamin B12 levels and cardiac changes in children with CRF, both conservative and hemodialyzed groups. Methods: Fifty children were studied in this work and were divided into two groups. Group I comprised 40 patients: twenty patients suffering from end stage renal disease (ESRD) on regular hemodialysis (HD) and 20 patients with CRF under conservative treatment. Group II comprised 10 control healthy children being age-and sex-matched with patients. The two groups were subjected to full history taking, clinical examination, routine investigations for CRF (blood urea, serum creatinine, serum calcium and phosphorus level, CBC). In addition the following markers were estimated once in the conservative group and before and after dialysis. In HD group: serum homocysteine, folic acid and vitamin B12 levels by high performance liquid chromatography. Cardiac measurements by echocardiography were done for all groups. Results: Serum (HCy) level was significantly elevated in HD and conservative group than in the control group. There was a significant increase in its level in HD compared with the conservative group. There was insignificant variation in HCy level before and after dialysis. Serum vit. B12 and folic acid were significantly lower in HD than in conservative groups. There was a significant decrease of their levels after dialysis than before. There was a significant negative correlation between HCy and folic acid and vit. B12 levels, while a highly significant positive correlation between HCy, blood urea and serum creatinine was found. Also there was a highly significant negative correlation between HCy and glomerular filtration rate (GFR), and a significant positive correlation between HCy and systolic and diastolic blood pressure. There is no significant correlation between HCy and left ventricular mass index (LVMI). However, interventricular septum diastolic thickness (IVSDT), left ventricular posterior wall diastolic and systolic thickness (LVPWDT), (LVPWST), left ventricular end diastolic thickness (LVEDD) and relative wall thickness (RWT) were significantly higher in dialyzed than in the conservative group. Conclusions: These data showed that serum homocysteine was significantly elevated in children with CRF which was more serious in the HD group due to lower level of vit. B12 and folic acid which were dialysed vitamins. Hyperhomo-cysteimia, may be one of risk factors hypertension, and left ventricular hypertrophy in children with CRF.