Summary
Elevated total homocysteine (tHcy) concentrations are an inde- pendent risk factor
for thromboembolic events in adults. In children with moderate hyperhomocysteinemia
data are sparse. Therefore, between 1995 and 2002 we consecutively recruited 163 white
pediatric patients with a first symptomatic thromboembolic event and 255 healthy controls
(mean age: 6.4 years in patients vs. 6.6 years in controls, range: 3 months to 18
years) and measured fasting tHcy levels. Median tHcy levels in patients were significantly
higher (6.6 µmol/l, range 2.9-20.4 µmol/l) than in controls (5.7 µmol/l, 2.0-14.0
µmol/l, p<0.0001). 48 of the 163 patients with thromboembolism (29.5%) versus 26 of
the 255 controls (10.2%) had tHcy levels above the age- specific normal 90th percentile
(OR 2.9, 95%CI: 1.7-4.8). The odds ratio for children in the highest quintile compared
to chil- dren with levels in the lowest quintile was 4.3 (1.6-8.1; highest quintile:
median tHcy level 9.6 µmol, range 8.0-20.4), showing a significantly increased risk
for thromboembolic disease with even mild hyperhomocysteinemia. We conclude that hyperho-
mocysteinemia above the age-specific cut-off values is a risk fac- tor for thromboembolic
events in children. Therefore, screen- ing for elevated fasting tHcy levels of patients
with thromboem- bolism is recommended to stratify the risk of thromboembo- lism.
Keywords
Homocysteine - hyperhomocysteinemia - thromboembolism - children