Umeta M, West C E, Haidar J, Deurenberg P, Hautvast J G
Ethiopian Health and Nutrition Research Institute, Addis Ababa.
Lancet. 2000 Jun 10;355(9220):2021-6. doi: 10.1016/S0140-6736(00)02348-5.
Stunting is highly prevalent in Ethiopia and many other developing countries but the reason for it is poorly understood. Zinc is essential for growth but diets in such countries often do not contain zinc in sufficient quantity or of sufficient bioavailability. Thus zinc deficiency may play a major role in stunting. The aim of the study was to investigate whether the low rate of linear growth of apparently healthy breastfed infants in a rural village in Ethiopia could be improved by zinc supplementation.
A randomised, double-blind, placebo-controlled trial was done on apparently healthy breastfed infants aged 6-12 months. 100 non-stunted (length-for-age, Z score < -2) were matched for age and sex with 100 randomly selected stunted (> -2) infants. Infants, both stunted and non stunted, were matched by sex, age (within 2 months) and recumbent length (within 3 cm) for random assignment, to receive a zinc supplement (10 mg zinc per day, as zinc sulphate) or placebo, 6 days a week for 6 months. Anthropometric measurements were taken monthly, data on illness and appetite were collected daily, and samples of serum and hair were taken at the end of the intervention for the analysis of zinc.
The length of stunted infants increased significantly more (p<0.001) when supplemented with zinc (7.0 cm [SE 1.1]) than with placebo (2.8 cm [0.9]); and the effect was greater (p<0.01) than in non-stunted infants (6.6 [0.9] vs 5.0 [0.8] cm for the zinc and placebo groups respectively, p<0.01). Zinc supplementation also increased the weight of stunted children (1.73 [0.39] vs 0.95 [0.39] kg for the corresponding placebo group, p<0.001) and of non-stunted children (1.19 [0.39] vs 1.02 [0.32] kg for the corresponding placebo group, p<0.05). Zinc supplementation resulted in a markedly lower incidence of anorexia and morbidity from cough, diarrhoea, fever, and vomiting in the stunted children. The total number of these conditions per child was 1.56 and 1.11 in the stunted and non-stunted zinc supplemented children versus 3.38 and 1.64 in the stunted and non-stunted placebo-treated children, respectively. At the end of the intervention period, the concentrations of zinc in serum and hair of stunted infants, who had not been supplemented with zinc, were lower than the respective concentrations of zinc in serum and hair of their non-stunted counterparts.
Combating zinc deficiency can increase the growth rate of stunted children to that of non-stunted infants in rural Ethiopia. This would appear to be due, at least in part, to reduction in morbidity from infection and increased appetite.
发育迟缓在埃塞俄比亚和许多其他发展中国家极为普遍，但人们对其原因知之甚少。锌对生长至关重要，但这些国家的饮食中往往锌含量不足或生物利用率不够。因此，锌缺乏可能在发育迟缓中起主要作用。本研究的目的是调查在埃塞俄比亚一个乡村，对看似健康的母乳喂养婴儿补充锌是否能提高其线性生长率。
对6至12个月大的看似健康的母乳喂养婴儿进行了一项随机、双盲、安慰剂对照试验。100名发育正常（年龄别身长Z评分＜-2）的婴儿按年龄和性别与100名随机挑选的发育迟缓（Z评分＞-2）婴儿匹配。发育迟缓和发育正常的婴儿按性别、年龄（相差2个月内）和卧位身长（相差3厘米内）匹配后随机分组，接受锌补充剂（每天10毫克锌，以硫酸锌形式）或安慰剂，每周6天，共6个月。每月进行人体测量，每天收集疾病和食欲数据，干预结束时采集血清和头发样本用于锌分析。
补充锌的发育迟缓婴儿身长增加显著更多（p＜0.001）（7.0厘米[标准误1.1]），高于补充安慰剂的婴儿（2.8厘米[0.9]）；且该效果比发育正常婴儿更显著（p＜0.01）（锌补充组和安慰剂组分别为6.6[0.9]厘米和5.0[0.8]厘米，p＜0.01）。补充锌还增加了发育迟缓儿童的体重（相应安慰剂组为1.73[0.39]千克和0.95[0.39]千克，p＜0.001）以及发育正常儿童的体重（相应安慰剂组为1.19[0.39]千克和1.02[0.32]千克，p＜0.05）。补充锌使发育迟缓儿童厌食及咳嗽、腹泻、发热和呕吐的发病率显著降低。发育迟缓及发育正常的锌补充儿童中，这些病症的儿童总数分别为1.56和1.11，而发育迟缓及发育正常的安慰剂治疗儿童中分别为3.38和1.64。在干预期结束时，未补充锌的发育迟缓婴儿血清和头发中的锌浓度低于其发育正常对应婴儿血清和头发中的锌浓度。
在埃塞俄比亚农村，对抗锌缺乏可使发育迟缓儿童的生长速度提高到发育正常婴儿的水平。这似乎至少部分归因于感染发病率降低和食欲增加。
