Total serum homocysteine, folate and vitamin B12 in a Greek school age population

Background & aims: Moderate hyperhomocysteinemia is an independent risk factor for cardiovascular disease (CVD) even among children. The purpose of this study is to investigate for the first time the distribution and determinants of total serum homocysteine (tHcy) levels in healthy Greek children. Methods: tHcy, folate, B12 were measured in 524 children (275 boys and 249 girls) aged 6-15 years old from different socioeconomic status in Northern Greece. Results: The geometric mean tHcy level for boys and girls was 7.8 (3.4-24.2) and 7.5 (3.9-29.0) μmol/L, respectively. Eighty one (15.4%) children had homocysteine levels above the upper reference limits (>10 μmol/L). The geometric mean serum tHcy level was significantly (P < 0.001) increasing with age; 6.4 (3.4-11.2) μmol/L was found in the age group of 6-9 yr (group1), 7.2(4.1-22.1) μmol/L in the one of 10-12 yr (group 2) and 8.5 (3.9-29.0) μmol/L in the one of 13-15 yr (group 3). Serum folate levels were found to be statistically significant (P < 0.001) between age group 1 and age group 3 [11.8 (4.66-20.00) vs. 7.5 (0.99-20.00) ng/mL) and between age group 2 and 3 [10.0 (1.82-20.0) vs. 7.5 (0.99-20.00) ng/mL]. Vitamin B12 levels were significantly (P < 0.001) different in the three age groups [1048 (117-2000), 805 (296-2000), 700 (214-2000) pg/mL] respectively. Age, BMI, waist circumference (WC), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were positively correlated with tHcy, whereas serum folate and vitamin B12 were negatively correlated. No association was found between tHcy levels and parental education status. In multiple linear regression analysis only age (Beta: 0.248, 95%, CI: (0.159-0.361), P < 0.05) and folate (Beta: 0.347, 95%, CI: [(-0.206)-(-0.118)], P < 0.05) were found significantly and independently associated with tHcy. Conclusions: tHcy levels were increasing with age and boys were found to have slightly higher levels than girls. Age and folate levels were the most significantly and independently determinants associated with tHcy. Children with tHcy levels above the upper reference limits (>10 μmol/L) were found to be correlated with BMI, WC, SBP, serum folate and vitamin B12 levels. These children should be encouraged to include high folate food items in their diet and where necessary folate supplements should be recommended. In addition, more prospective studies are necessary in order to evaluate the relationship of tHcy and CVD risk factors in children of our region.