学龄前儿童血红蛋白浓度与智力发育水平的相关性研究

目的 探讨学龄前儿童血红蛋白(Hb)浓度与智力发育水平之间的相关性.方法 研究对象为河北、江苏、浙江3省21个市县1993-1996年出生的7331名儿童.平均54月龄时测量Hb浓度;平均68月龄时使用中国-韦氏幼儿智力量表进行智力测试.分析Hb浓度与全量表智商、语言智商和操作智商得分之间的关系.结果 贫血组与非贫血组儿童的语言智商得分分别为91.6±18.0、92.3±17.5(P=0.144),操作智商得分分别为102.2±15.6、103.1±15.0(P=0.055),全量表智商得分分别为96.4±17.1、97.3±16.4(P=0.079).调整儿童性别、智力测量时月龄、地区、产次以及母亲智商、文化程度、职业等因素之后,贫血组儿童发生低语言智商、操作智商、全量表智商得分的风险是非贫血儿童的1.3倍(OR=1.3,95%CI:1.1～1.6)、1.3倍(OR=1.3,95%CI:1.1～1.5)和1.4倍(OR=1.4,95%CI:1.2～1.6).按照每20个百分位间隔将lib浓度分成5组分析,Hb浓度偏低组(Hb＜110 g/l)、中等浓度组(117 g/L≤Hb＜122 g/L)、偏高组(Hb≥130 g/L)儿童的语言智商得分分别为90.6±18.1、94.0±17.6、91.0±16.4;操作智商得分分别为102.2±15.7、104.6±14.8、100.5±14.9,全量表智商得分分别为95.9±17.3、99.0±16.4、95.2±15.6;Hb浓度偏低或偏高组儿童的智力得分均低于Hb水平中等组,差异有统计学意义(P＜0.001).调整混杂因素后,Hb浓度偏低组儿童发生语言智商、操作智商、全量表智商得分较低的风险是Hb浓度中等浓度组儿童的1.4倍(OR=1.4,95%CI:1.1～1.7)、1.4倍(OR=1.4,95%CI:1.1～1.8)和1.5倍(OR=1.5,95%CI:1.2～1.8).未见Hb浓度偏高组儿童发生低智商得分的风险高于Hb水平中等组.结论 儿童低Hb浓度可能对智力发育有不利影响.

Correlation on hemoglobin concentration and the development of cognition among pre-school children

Objective Our purpose was to evaluate the association between hemoglobin concentration (Hb) and cognitive ability of children at 4-6 years of age in 21 counties/cities in China.Methods A total number of 7331 children born during 1993-1996 were randomly selected from 21 counties or cities in Hebei,Jiangsu and Zbejiang provinces,Hb concentration of children were measured followed by three tests including full-scale,verbal and performance intelligence quotient (IQ) test performed by Chinese-Wechsler Intelligence Scale for Children,one year later.Results There were a 0.7 point difference in mean verbal scale IQ(P=0.144) and a 0.9 point difference in both mean performance and full-scale IQ (P=0.055 and 0.079,respectively) between anemia and non-anemia groups.Compared with children with non-anemia,children with anemia were 1.3-fold more likely to score poorly in verbal IQ and operational IQ (95%CI:1.1-1.6,1.1-1.5,respectively) and 1 A-fold more likely to have had poor scores in full-scale IQ(95%CI:1.2-1.6) after controlled for children's gender,age at intelligence test,region,parity and mother's IQ,education level,occupation.Participants were divided into 5 sub-groups according to Hb concentration of every 20 percentile.Verbal IQ scores of the lowest(Hb＜110 g/L),moderate (117 g/L≤Hb＜122 g/L) and the highest Hb concentration groups (Hb≥130 g/L) were 90.6±18.1,94.0±17.6 and 91.0±16.4,respectively.Performance IQ scores were 102.2±15.7,104.6±14.8 and 100.5±14.9,respectively.Full-scale IQ scores were 95.94±17.3,99.0±16.4 and 95.2±15.6,respectively.Children with both low and high hemoglobin levels did poorly in all intelligence tests than children with moderate Hb concentration (P＜0.001).After controlling for confounding factors,children with the lowest concentration were 1.4-fold more likely to have had poor verbal and performance scores than children with moderate Hb concentration (95% CI:1.1-1.7,1.1-1.8,respectively) and 1.5-fold (95% CI:1.2-1.8) more likely to have had poor full-scale scores than those with moderate Hb concentration.The association between high Hb concentration and low IQ scores disappeared in the multivariate model.Conclusion Low Hb concentration might have adversely affected children' s cognitive development.