A recently discussed cardiovascular risk factor, asymmetric
dimethylarginine (ADMA), is known to act as an endogenous
inhibitor of endothelial nitric oxide synthase. The aim of this
study was to establish 1) the relationship between ADMA and
ultrasonographically or biochemically determined endothelial
dysfunction in children, and 2) the effect of folate
supplementation on these parameters. The study cohort included
32 children with familial hypercholesterolemia (FH), 30 with
diabetes mellitus type 1 (DM1) and 30 age-matched healthy
children as the control group. Furthermore, twenty-eight
randomly selected FH and DM1 children were re-examined after
3-months supplementation with folic acid. Baseline levels of
ADMA and oxidized low density lipoproteins (oxLDL) were
significantly higher in FH group than in DM1 and healthy children.
Children in DM1 group had significantly lower concentration of
homocysteine, but ADMA levels were normal. Folic acid
supplementation significantly lowered homocysteine and hsCRP
levels in both FH and DM1 group; however, ADMA and oxLDL
concentrations remained unaltered. In conclusion, ADMA and
oxLDL appear to be associated with endothelial dysfunction in
children with FH. Administration of folic acid did not influence
these markers in both FH and DM1 children.