Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine, Fajara, The Gambia; Centre on Climate Change and Planetary Health, London School of Hygiene & Tropical Medicine, London, UK.
Institute of Social and Preventive Medicine and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland.
Lancet Planet Health. 2024 Oct;8(10):e734-e743. doi: 10.1016/S2542-5196(24)00208-0.
The intersecting crises of climate change, food insecurity, and undernutrition disproportionately affect children. Understanding the effect of heat on growth from conception to 2 years of age is important because of mortality and morbidity implications in the near term and over the life course.
In this secondary analysis, we used longitudinal pregnancy cohort data from the Early Nutrition and Immunity Development (ENID) randomised controlled trial in West Kiang, The Gambia, which occurred between Jan 20, 2010, and Feb 10, 2015. The ENID trial assessed micronutrient supplementation in the first 1000 days of life starting from 20 weeks' gestation, during which anthropometric measurements were collected prospectively. We used multivariable linear regression to assess the effect of heat stress (defined by Universal Thermal Climate Index [UTCI]) on intrauterine growth restriction based on length-for-gestational age Z score (LGAZ), weight-for-gestational age Z score (WGAZ), and head circumference-for-gestational age Z score (HCGAZ) at birth, and assessed for effect modification of supplement intervention on the relationship between heat stress and infant anthropometry. We used multivariable, multilevel linear regression to evaluate the effect of heat stress on infant growth postnatally based on weight-for-height Z score (WHZ), weight-for-age Z score (WAZ), and height-for-age Z score (HAZ) from 0 to 2 years of age.
Complete data were available for 668 livebirth outcomes (329 [49%] female infants and 339 [51%] male infants). With each 1°C increase in mean daily maximum UTCI exposure, in the first trimester, we observed a reduction in WGAZ (-0·04 [95% CI -0·09 to 0·00]), whereas in the third trimester, we observed an increase in HCGAZ (0·06 [95% CI 0·00 to 0·12]), although 95% CIs included 0. Maternal protein-energy supplementation in the third trimester was associated with reduced WGAZ (-0·16 [-0·30 to -0·02]) with each 1°C increase in mean daily maximum UTCI exposure, while no effect of heat stress on WGAZ was found with either standard care (iron and folate) or multiple micronutrient supplementation. For the postnatal analysis, complete anthropometric data at 2 years were available for 645 infants (316 [49%] female infants and 329 [51%] male infants). Postnatally, heat stress effect varied by infant age, with infants aged 6-18 months being the most affected. In infants aged 12 months exposed to a mean daily UTCI of 30°C (preceding 90-day period) versus 25°C UTCI, we observed reductions in mean WHZ (-0·43 [95% CI -0·57 to -0·29]) and mean WAZ (-0·35 [95% CI -0·45 to -0·26]). We observed a marginal increase in HAZ with increasing heat stress exposure at age 6 months, but no effect at older ages.
Our results suggest that heat stress impacts prenatal and postnatal growth up to 2 years of age but sensitivity might vary by age. In the context of a rapidly warming planet, these findings could have short-term and long-term health effects for the individual, and immediate and future implications for public child health.
Wellcome Trust.
气候变化、粮食不安全和营养不足等交叉危机对儿童的影响尤为严重。了解从受孕到 2 岁期间热量对生长的影响很重要，因为这会对近期和整个生命周期的死亡率和发病率产生影响。
在这项二次分析中，我们使用了来自冈比亚西部 ENID 随机对照试验的纵向妊娠队列数据，该试验于 2010 年 1 月 20 日至 2015 年 2 月 10 日进行。ENID 试验评估了从 20 周妊娠开始的生命最初 1000 天中的微量营养素补充，在此期间前瞻性地收集了人体测量学数据。我们使用多变量线性回归来评估热应激（由通用热气候指数 [UTCI] 定义）对宫内生长受限的影响，根据胎龄的长度 Z 评分（LGAZ）、体重 Z 评分（WGAZ）和头围 Z 评分（HCGAZ）出生时，评估补充干预对热应激与婴儿人体测量学之间关系的影响修饰作用。我们使用多变量、多层次线性回归来评估热应激对出生后婴儿生长的影响，根据 0 至 2 岁时的体重-身高 Z 评分（WHZ）、体重-年龄 Z 评分（WAZ）和身高-年龄 Z 评分（HAZ）进行评估。
共有 668 例活产结局（329 名[49%]女婴和 339 名[51%]男婴）的数据完整。与每日最大平均日 UTCI 暴露增加 1°C 相比，在妊娠早期，我们观察到 WGAZ 降低（-0.04 [95%CI-0.09 至 0.00]），而在妊娠晚期，我们观察到 HCGAZ 增加（0.06 [95%CI 0.00 至 0.12]），尽管 95%CI 包括 0。在妊娠晚期，母亲的蛋白质-能量补充与每日最大平均 UTCI 暴露每增加 1°C 时 WGAZ 减少（-0.16 [-0.30 至 -0.02]）有关，而标准护理（铁和叶酸）或多种微量营养素补充对 WGAZ 没有热应激的影响。对于产后分析，645 名婴儿（316 名[49%]女婴和 329 名[51%]男婴）在 2 岁时具有完整的人体测量数据。产后，热应激的影响因婴儿年龄而异，6-18 个月的婴儿受影响最大。在暴露于 30°C （前 90 天）的平均每日 UTCI 而不是 25°C UTCI 的 12 个月大的婴儿中，我们观察到平均 WHZ（-0.43 [95%CI-0.57 至 -0.29]）和平均 WAZ（-0.35 [95%CI-0.45 至 -0.26]）降低。我们观察到 6 个月时随着热应激暴露的增加，HAZ 略有增加，但在年龄较大时没有影响。
我们的结果表明，热应激会影响产前和产后 2 岁以下的生长，但敏感性可能因年龄而异。在地球迅速变暖的背景下，这些发现可能会对个人的短期和长期健康产生影响，并对公共儿童健康产生即时和未来的影响。
威康信托基金会。
