Halterman J S, Kaczorowski J M, Aligne C A, Auinger P, Szilagyi P G
Department of Pediatrics, University of Rochester School of Medicine and Dentistry, NY, USA.
Pediatrics. 2001 Jun;107(6):1381-6. doi: 10.1542/peds.107.6.1381.
Iron deficiency anemia in infants can cause developmental problems. However, the relationship between iron status and cognitive achievement in older children is less clear.
To investigate the relationship between iron deficiency and cognitive test scores among a nationally representative sample of school-aged children and adolescents.
The National Health and Nutrition Examination Survey III 1988-1994 provides cross-sectional data for children 6 to 16 years old and contains measures of iron status including transferrin saturation, free erythrocyte protoporphyrin, and serum ferritin. Children were considered iron-deficient if any 2 of these values were abnormal for age and gender, and standard hemoglobin values were used to detect anemia. Scores from standardized tests were compared for children with normal iron status, iron deficiency without anemia, and iron deficiency with anemia. Logistic regression was used to estimate the association of iron status and below average test scores, controlling for confounding factors.
Among the 5398 children in the sample, 3% were iron-deficient. The prevalence of iron deficiency was highest among adolescent girls (8.7%). Average math scores were lower for children with iron deficiency with and without anemia, compared with children with normal iron status (86.4 and 87.4 vs 93.7). By logistic regression, children with iron deficiency had greater than twice the risk of scoring below average in math than did children with normal iron status (odds ratio: 2.3; 95% confidence interval: 1.1-4.4). This elevated risk was present even for iron-deficient children without anemia (odds ratio: 2.4; 95% confidence interval: 1.1-5.2).
We demonstrated lower standardized math scores among iron-deficient school-aged children and adolescents, including those with iron deficiency without anemia. Screening for iron deficiency without anemia may be warranted for children at risk.
婴儿缺铁性贫血会导致发育问题。然而，年龄较大儿童的铁状态与认知成绩之间的关系尚不清楚。
在全国具有代表性的学龄儿童和青少年样本中，调查缺铁与认知测试分数之间的关系。
1988 - 1994年的第三次全国健康和营养检查调查提供了6至16岁儿童的横断面数据，并包含铁状态的测量指标，包括转铁蛋白饱和度、游离红细胞原卟啉和血清铁蛋白。如果这些值中的任何两项在年龄和性别方面异常，则认为儿童缺铁，并使用标准血红蛋白值检测贫血。比较了铁状态正常、缺铁但无贫血以及缺铁伴贫血儿童的标准化测试分数。采用逻辑回归来估计铁状态与低于平均测试分数之间的关联，并控制混杂因素。
样本中的5398名儿童中，3%缺铁。缺铁患病率在青春期女孩中最高（8.7%）。与铁状态正常的儿童相比，缺铁伴贫血和缺铁但无贫血的儿童平均数学分数较低（分别为86.4和87.4，而铁状态正常的儿童为93.7）。通过逻辑回归分析，缺铁儿童数学得分低于平均水平的风险是铁状态正常儿童的两倍多（优势比：2.3；95%置信区间：1.1 - 4.4）。即使是缺铁但无贫血的儿童也存在这种风险升高的情况（优势比：2.4；95%置信区间：1.1 - 5.2）。
我们证明了缺铁的学龄儿童和青少年，包括那些缺铁但无贫血的儿童，其标准化数学分数较低。对于有风险的儿童，可能有必要筛查缺铁但无贫血的情况。
