Addis Ababa University, College of Natural and Computational Sciences, Center for Food Science and Nutrition, Addis Ababa, Ethiopia.
International Food Policy Research Institute, Development Strategy and Governance Division, Addis Ababa, Ethiopia.
JAMA Pediatr. 2020 Oct 1;174(10):977-984. doi: 10.1001/jamapediatrics.2020.2386.
Irrespective of their genetic makeup, children living in an ideal home environment that supports healthy growth have similar growth potential. However, whether this potential is true for children residing at higher altitudes remains unknown.
To investigate whether altitude is associated with increased risk of linear growth faltering and evaluate the implications associated with the use of the 2006 World Health Organization growth standards, which have not been validated for populations residing 1500 m above sea level.
DESIGN, SETTINGS, AND PARTICIPANTS: Analysis of 133 nationally representative demographic and health cross-sectional surveys administered in 59 low- and middle-income countries using local polynomial and multivariate regression was conducted. A total of 964 299 height records from 96 552 clusters at altitudes ranging from -372 to 5951 m above sea level were included. Demographic and Health Surveys were conducted between 1992 and 2018.
Residence at higher altitudes, above and below 1500 m above sea level, and in ideal home environments (eg, access to safe water, sanitation, and health care).
The primary outcome was child linear growth deficits expressed in length-for-age/height-for-age z scores (HAZ). Associations between altitude and height among all children and those residing in ideal home environments were assessed. Child growth trajectories above and below 1500 m above sea level were compared and the altitude-mediated height deficits were estimated using multivariable linear regression.
In 2010, a total of 842 million people in the global population (approximately 12%) lived 1500 m above sea level or higher, with 67% in Asia and Africa. Eleven percent of the sample was children who resided 1500 m above sea level or higher. These children were born at shorter length and remained on a lower growth trajectory than children residing in areas less than 1500 m above sea level. The negative association between altitude and HAZ was approximately linear through most part of the altitude distribution, indicating no clear threshold for an abrupt decrease in HAZ. A 1000-m above sea level increase in altitude was associated with a 0.163-unit (95% CI, -0.205 to -0.120 units) decrease in HAZ after adjusting for common risk factors using multivariable linear regressions. The HAZ distribution of children residing in ideal home environments was similar to the 2006 World Health Organization HAZ distribution, but only up to 500 m above sea level.
The findings of this study suggest that residing at a higher altitude may be associated with child growth slowing even for children living in ideal home environments. Interventions addressing altitude-mediated growth restrictions during pregnancy and early childhood should be identified and implemented.
无论其遗传构成如何，生活在支持健康成长的理想家庭环境中的儿童都具有相似的生长潜力。然而，居住在更高海拔地区的儿童是否具有这种潜力尚不清楚。
研究海拔是否与线性生长迟缓的风险增加有关，并评估使用 2006 年世界卫生组织生长标准的影响，该标准尚未在海拔 1500 米以上的人群中得到验证。
设计、地点和参与者：使用局部多项式和多变量回归分析了来自 59 个中低收入国家的 133 项具有全国代表性的人口和健康横断面调查的数据。共纳入了来自海拔-372 至 5951 米的 964299 个身高记录，来自 96552 个聚类。这些调查是在 1992 年至 2018 年期间进行的。
居住在高海拔地区（海拔 1500 米以上）和理想家庭环境（如获得安全用水、卫生设施和医疗保健）中。
主要结局是儿童线性生长不足，表现为年龄/身高年龄 z 分数（HAZ）。评估了海拔与所有儿童和居住在理想家庭环境中的儿童身高之间的关系。比较了海拔高于和低于 1500 米的儿童生长轨迹，并使用多变量线性回归估计了海拔介导的身高不足。
2010 年，全球人口中约有 12%（约 8.42 亿人）生活在海拔 1500 米或以上的地区，其中 67%在亚洲和非洲。样本中有 11%是居住在海拔 1500 米或以上地区的儿童。这些儿童出生时的身长较短，并且其生长轨迹低于海拔 1500 米以下地区的儿童。海拔与 HAZ 之间的负相关关系在大部分海拔分布中呈近似线性，表明 HAZ 没有明显的下降阈值。使用多变量线性回归调整常见风险因素后，海拔每升高 1000 米，HAZ 就会下降 0.163 个单位（95%CI，-0.205 至-0.120 个单位）。居住在理想家庭环境中的儿童的 HAZ 分布与 2006 年世界卫生组织的 HAZ 分布相似，但仅在海拔 500 米以下。
这项研究的结果表明，即使对于生活在理想家庭环境中的儿童，居住在高海拔地区也可能与儿童生长缓慢有关。应确定并实施解决怀孕期间和儿童早期由海拔引起的生长受限的干预措施。
