Domellöf Magnus, Lönnerdal Bo, Dewey Kathryn G, Cohen Roberta J, Rivera L Landa, Hernell Olle
Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden.
Pediatrics. 2002 Sep;110(3):545-52. doi: 10.1542/peds.110.3.545.
It is commonly assumed that there is no difference in iron status between male and female infants, despite a lack of studies addressing this question.
To study sex differences in different measures of iron status in infants.
At 4 months of age, 263 term, breastfed infants (121 Swedish and 142 Honduran) were randomized to receive iron supplements or placebo until 9 months of age. Blood samples at 4, 6, and 9 months of age were analyzed for hemoglobin (Hb), mean cell volume (MCV), zinc protoporphyrin (ZPP), plasma ferritin, and transferrin receptors (TfR).
At 4, 6, and 9 months, boys had significantly lower Hb, MCV, and ferritin and higher ZPP and TfR than girls. At 9 months, boys had a 10-fold higher risk of being classified as having iron deficiency anemia. The differences at 9 months in MCV (71.6 vs 75.1 fL) and ZPP (59 vs 49 micro mol/mol heme) remained significant after controlling for iron supplementation, site, growth variables, and other possible confounders. For ferritin, there was a remaining sex difference at 9 months among Swedish (29 vs 53 micro g/L) but not Honduran infants. For Hb and TfR, sex differences at 9 months were larger in unsupplemented infants, especially in those with a birth weight of <3500 g.
There are substantial sex differences in Hb and other indicators of iron status during infancy. Some of these may be genetically determined, whereas others seem to reflect an increased incidence of true iron deficiency in boys.
尽管缺乏针对这一问题的研究，但人们普遍认为男婴和女婴的铁营养状况没有差异。
研究婴儿铁营养状况不同指标中的性别差异。
263名足月、母乳喂养的4月龄婴儿（121名瑞典婴儿和142名洪都拉斯婴儿）被随机分为两组，一组接受铁补充剂，另一组接受安慰剂，直至9月龄。对4、6和9月龄时采集的血样进行血红蛋白（Hb）、平均红细胞体积（MCV）、锌原卟啉（ZPP）、血浆铁蛋白和转铁蛋白受体（TfR）分析。
在4、6和9月龄时，男孩的Hb、MCV和铁蛋白水平显著低于女孩，而ZPP和TfR水平则高于女孩。在9月龄时，男孩被归类为缺铁性贫血的风险高出10倍。在控制了铁补充剂、研究地点、生长变量和其他可能的混杂因素后，9月龄时MCV（71.6对75.1 fL）和ZPP（59对49微摩尔/摩尔血红素）的差异仍然显著。对于铁蛋白，9月龄时瑞典婴儿（29对53微克/升）存在性别差异，而洪都拉斯婴儿则不存在。对于Hb和TfR，未补充铁剂的婴儿在9月龄时的性别差异更大，尤其是出生体重<3500 g的婴儿。
婴儿期Hb和其他铁营养状况指标存在显著的性别差异。其中一些可能由基因决定，而另一些似乎反映出男孩真正缺铁的发生率增加。
