Plasma homocysteine concentrations in a Belgian school-age population

Background: Total plasma homocysteine (tHcy) is an independent risk factor for cardiovascular disease in adults. Data for children and adolescents are lacking. Objective: The aim of this study was to provide a reference range for tHcy and to explore the relation between tHcy and nutritional indexes in a Belgi an pediatric population. Design: tHcy, folate, and vitamin B-12 were measured in 647 healthy childre n (353 girls and 294 boys) aged 5-19 y. Results: The tHcy distribution was, as in adults, skewed to the right [geom etric mean (-1 SD, +1 SD): 7.41 mu mol/L (5.51, 9.96)]. Concentrations were lowest in younger children and increased with age. After the tHcy distribu tion was examined according to age, 3 age ranges were distinguished: 5-9 y [6.21 mu mol/L (5.14, 7.50)], 10-14 y [7.09 mu mol/L (5.69, 8.84)], and 15- 19 y [8.84 mu mol/L (6.36, 12.29)]. We observed no significant differences in tHcy values between girls and boys in children aged <15 y; in postpubert al children, however, concentrations were higher in boys than in girls. In the 3 age groups, folate was inversely correlated with tHcy; the negative r elation between tHcy and vitamin B-12 was less strong. Familial cardiovascu lar disease was more frequent in children who had hyperhomocysteinemia. Conclusions: These observations suggest that in children, as in adults, gen etic, nutritional, and endocrine factors are determinants of the metabolism of homocysteine. The significance of tHcy values in childhood and young ad ulthood in terms of predicting cardiovascular risk in adulthood should be i nvestigated.