Hyperhomocysteinemia, enzyme polymorphism and thiobarbituric Acid reactive system in children with high coronary risk family history.

OBJECTIVE

To investigate both the frequency and the genetic background of hyperhomocysteinemia and the frequency of increased plasma thiobarbituric acid reactive system (TBARS) levels in children and adolescents whose parents had premature coronary heart disease (CHD).

METHODS

The study was performed on children and adolescents aged 4-18 years (105 offspring of parents with CHD before age 45 and 74 referents from families without any evidence of premature atherosclerosis). Fasting serum total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), and total triglyceride (TG) levels were measured by enzymatic methods. Low density lipoprotein cholesterol (LDL-C) level was calculated by the Friedewald formula. Plasma total homocysteine (THCy) level was measured by fluorescence polarisation immunoassay. Plasma TBARS level was determined by fluorimetric method. 5,10-methylenetetrahydrofolate reductase (MTHFR) enzyme polymorphism was analyzed by polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Hyperhomocysteinemia was found in 32 cases and in 4 controls. Increased plasma THCy level was found in 10 children and adolescents from 12 cases homozygous for the C677T polymorphism of the MTHFR gene. No similar high frequency was observed in heterozygous subjects. Elevated fasting plasma TBARS levels were found in 38 cases and in 8 controls. The frequency differences were significant (p < 0.01). Allele frequency of the MTHFR polymorphism among cases and controls was similar. Significant correlation (r = 0.53, p < 0.02) was detected between plasma THCy and TBARS levels. One child had high serum TC level, 5 had low serum HDL-C level and all other children had normal serum TC, LDL-C, HDL-C and TG levels from children with hyperhomocysteinemia and/or high plasma TBARS levels. A significant correlation (r = 0.64, p < 0.01) was observed between plasma THCy levels of parents and children in the case group.

CONCLUSIONS

The measurement of plasma THCy and TBARS levels may contribute to the detection of the risk of children and adolescents with high CHD risk family history.