Background: children with familiar hypercholesterolemia (FH) and diabetes mellitus type 1 (DM1) are considered to be high risk groups for the early manifestation of atherosclerosis. Endothelial dysfunction (ED) should be assessed in the preclinical stage, before clinical symptoms of vascular complications occur. Besides ultrasonographic methods there are many biochemical markers of ED whose varying sensitivity and specifity make diagnosis of ED in children difficult.

Methods: high selective CRP (hsCRP), oxidized LDL (oxLDL), malondialdehyde (MDA) and asymmetric dimethylarginine (ADMA) were assessed in three groups of children. FH group (n = 29, mean age 13.9 years, on a low-fat diet 17, statins 6, resins 6), DM1 group (n = 22, mean age 14.5 years, average duration 4.8 years) and a group of healthy controls (n = 17, mean age 15.3 years). Flow mediated dilation (FMD) and Deceleration index (DI) were measured simultaneously. Biochemical markers were then correlated with the ultrasonographic markers of ED.

Results: ADMA levels in the FH group were 0.97umol/l (SE 0.03), DM1 group 0.85 umol/l (SE 0.05) and in healthy controls 0.70umol/l (SE 0.04). Statistically significant differences were found between the FH group and healthy controls (p < 0.00001), and between DM1 group and healthy controls (p < 0.01). Differences in Hcy, hsCRP, OxLDL and MDA in these groups were not statistically significant. Interestingly both ultrasonographic methods used in this study did not show any significant difference between the study and control groups.

Conclusion: ADMA appears to be a more sensitive marker for the detection of ED than currently used ultrasonographic methods in children. Unlike other tested biochemical markers of ED, ADMA could be an important factor determining the treatment strategy. Nevertheless the combination of biochemical and ultrasonographic markers should continue to play an essential role in the treatment strategy in high risk children.