Emond A M, Hawkins N, Pennock C, Golding J
Institute of Child Health, Royal Hospital for Sick Children, St Michael's Hill, Bristol.
Arch Dis Child. 1996 Jan;74(1):36-9. doi: 10.1136/adc.74.1.36.
To identify the optimum age to screen for iron deficiency, the normal distribution of haemoglobin and ferritin in a representative population sample was investigated.
Normal values for haemoglobin and ferritin were measured from heel prick capillary samples obtained from a representative cohort of 1175 infants at 8 months old who were randomly selected from children taking part in the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC).
Haemoglobin was normally distributed: mean (SD) 117 (11) milligrams, 95% confidence interval (CI) 116 to 118, and range 72-153 milligrams. Ferritin was log normally distributed: geometric mean 38.5 micrograms/l, 95% CI 37.0 to 39.9, range 7.1-224 micrograms/l. The 5th centile for haemoglobin was 97 milligrams and for ferritin 16.9 micrograms/l. No correlation was found between haemoglobin and ferritin. Multiple regression analysis showed ferritin concentrations to be positively related to birth weight (p < 0.0001) and the sex of the child (girls with higher concentrations) (p < 0.0001) but negatively with the child's weight at 8 months (p < 0.0001). Haemoglobin concentrations were positively related to the child's weight at 8 months (p = 0.04). Neither haemoglobin nor ferritin concentrations were related to social class as measured by maternal education level.
These data define the normal range for haemoglobin and ferritin in capillary samples in the UK population, and suggest that anaemia is common in infancy. Using current recommendations, 23% of infants would be identified as anaemic. For British infants at 8 months of age, a more representative 'cut off' for anaemia would be haemoglobin concentration < 97 milligrams and for iron deficiency ferritin < 16 micrograms/l.
为确定筛查缺铁的最佳年龄，对具有代表性的人群样本中血红蛋白和铁蛋白的正态分布进行了研究。
从参与雅芳孕期与儿童纵向研究（ALSPAC）的儿童中随机选取1175名8月龄婴儿组成代表性队列，采集足跟毛细血管样本，测定血红蛋白和铁蛋白的正常值。
血红蛋白呈正态分布：均值（标准差）为117（11）毫克，95%置信区间（CI）为116至118，范围为72 - 153毫克。铁蛋白呈对数正态分布：几何均值为38.5微克/升，95%CI为37.0至39.9，范围为7.1 - 224微克/升。血红蛋白的第5百分位数为97毫克，铁蛋白为16.9微克/升。未发现血红蛋白与铁蛋白之间存在相关性。多元回归分析显示，铁蛋白浓度与出生体重呈正相关（p < 0.0001），与儿童性别有关（女孩浓度较高）（p < 0.0001），但与8月龄时儿童体重呈负相关（p < 0.0001）。血红蛋白浓度与8月龄时儿童体重呈正相关（p = 0.04）。血红蛋白和铁蛋白浓度均与以母亲教育水平衡量的社会阶层无关。
这些数据确定了英国人群毛细血管样本中血红蛋白和铁蛋白的正常范围，并表明贫血在婴儿期很常见。按照当前建议，23%的婴儿会被判定为贫血。对于8月龄的英国婴儿，更具代表性的贫血“临界值”为血红蛋白浓度<97毫克，缺铁为铁蛋白<16微克/升。
