Linear Growth Deficit Continues to Accumulate beyond the First 1000 Days in Low- and Middle-Income Countries: Global Evidence from 51 National Surveys
Linear Growth Deficit Continues to Accumulate beyond the First 1000 Days in Low- and Middle-Income Countries: Global Evidence from 51 National Surveys
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DOI：
10.3945/jn.114.191981
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发表时间：
2014-09-01
影响因子：
4.2
通讯作者：
Frongillo, Edward A.
中科院分区：
文献类型：
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作者：
Leroy, Jef L.;Ruel, Marie;Frongillo, Edward A.
生长迟缓通常用年龄-身高z分数（HAZs）来评估，该分数被用于比较人口中不同年龄和性别组成的儿童。由于计算HAZ的标准差（分母）随着年龄的增长而增加，因此HAZ对评估身高随时间（跨年龄）变化的有用性是不确定的。我们假设，随着人口年龄的增长，人口水平的身高变化应该使用绝对身高年龄差（HADs）而不是HADs来评估。我们使用了来自低收入和中等收入国家的51项全国性调查的数据，并绘制了按年龄划分的平均HADs和HADs图表。我们还使用这两种方法计算了HADs和HADs的年变化以及从出生到60个月每年累积的总身高不足的百分比。平均HAZ开始于-0.4 z分数，并在24个月后急剧下降，之后稳定并且没有进一步恶化。平均HAD开始于-0.8 cm，最明显的动摇发生在6至18个月之间，与HAZ相似。然而，与HAZ形成鲜明对比的是，从18个月到60个月，HAD曲线的线性增长赤字持续增加，没有迹象表明趋于平稳。在全球范围内，发现60月龄时累积的绝对身高缺陷（HAD）的70%是由于最初“1000天”（怀孕至24月龄）的蹒跚，但30%是由于2岁至5岁期间身高缺陷的持续增加。由于年龄相关的SD变化，HAZ的使用掩盖了这些变化。因此，HAD，而不是HAZ，应该用来描述和比较儿童年龄的身高变化，因为在儿童成长过程中发现任何与预期身高变化相比的缺陷是很重要的，只有HAD在所有年龄段都能准确地做到这一点。我们的研究结果支持了目前全球关注前1000天的规划势头。需要通过使用准确反映年龄变化的指数和指标来更好地理解线性生长停滞的动态和时间，并确定经济有效的方法来防止生长停滞及其在整个生命周期中的后果。
Growth faltering is usually assessed using height-for-age Z-scores (HAZs), which have been used for comparisons of children of different age and sex composition across populations. Because the SD (denominator) for calculating HAZ increases with age, the usefulness of HAZs to assess changes in height over time (across ages) is uncertain. We posited that population-level changes in height as populations age should be assessed using absolute height-for-age differences (HADs) and not HAZs. We used data from 51 nationwide surveys from low- and middle-income countries and graphed mean HAZs and HADs by age. We also calculated annual changes in HAZs and HADs and percentage of total height deficit accumulated annually from birth to age 60 mo using both approaches. Mean HAZ started at -0.4 Z-scores and dropped dramatically up to 24 mo, after which it stabilized and-had no additional deterioration. Mean HAD started at -0.8 cm, with the most pronounced faltering occurring between 6 and 18 mo, similar to HAZ. However, in sharp contrast to HAZ, HAD curves had continued increases in the deficit of linear growth from 18 to 60 mo, with no indication of a leveling off. Globally, 70% of the absolute deficit accumulated in height (HAD) at 60 mo was found to be due to faltering during the first "1000 days" (conception to 24 mo), but 30% was due to continued increases in deficit from age 2 to 5 y. The use of HAZ masks these changes because of age-related changes in SD. Therefore, HAD, rather than HAZ, should be used to describe and compare changes in height as children age because detecting any deficit compared with expected changes in height as children grow is important and only HAD does this accurately at all ages. Our findings support the current global programmatic momentum to focus on the first 1000 d. Research is needed to better understand the dynamics and timing of linear growth faltering using indices and indicators that accurately reflect changes over ages and to identify cost-effective ways to prevent growth faltering and its consequences throughout the lifecycle.