Objective: To quantitatively assess the concentration and distribution of body iron(BI) in children aged 6 to 17 years in Beijing.
Methods: A total of 1392 children aged 6 to 17 years in Beijing were randomly selected for questionnaire survey and physical examination in 2016-2017. Fasting venous blood was collected, serum ferritin(SF) and serum soluble transferrin receptor(sTfR) were measured by immunoturbidimetric assay. BI were calculated, and the concentration and distribution of BI in children aged 6 to 17 years was assessed.
Results: The average BI level of children aged 6 to 17 in Beijing was(5.49±2.94) mg/kg. The average BI level of boys was higher than that of girls, and the average BI level of children with abdominal obesity was higher than that of children without abdominal obesity, and the differences were statistically significant(P<0.05). The concentration of BI in children aged 6 to 17 years in Beijing was 4-7.99 mg/kg, accounting for the highest proportion(57.3%). The concentration of BI<0 mg/kg accounted for the lowest proportion(4.3%). There were significant differences in the distribution of BI concentration in different gender, age and abdominal obesity(P<0.05). The anemia rate of children aged 6 to 17 in Beijing was 2.7%(95%CI 1.9-3.6), the low ferritin rate(SF<25 μg/L) was 22.5%(95%CI 20.0-24.8), and the iron deficiency rate(SF<15 μg/L) was 7.8%(95%CI 6.4-9.3), the negative iron stores(BI<0 mg/kg) rate was 4.3%(95%CI 3.2-5.3). The anemia rate, low ferritin rate, iron deficiency rate and negative iron stores rate were higher in girls than boys, and higher in children aged 12 to 17 years than in children aged 6 to 11 years, and the differences were statistically significant(P<0.01).
Conclusion: Iron deficiency was still present in children aged 6 to 17 in Beijing from 2016 to 2017. The proportion of low BI level in girls and children aged 12 to 17 is higher, respectively.
Keywords: body iron; children aged 6 to 17; serum ferritin; serum soluble transferrin receptor.