Famine Exposure During the First 1000 Days and Intellectual Disability

描述（由申请人提供）：我们的目标是促进对生命最初1000天（从怀孕到2岁）营养作用的理解，这是大脑发育的关键和脆弱阶段，对智力和其他残疾以及学校教育的影响。我们建议对1959-61年中国饥荒的长期影响进行研究，这是人类历史上最大的饥荒，死亡人数高达3000万至5000万人。这场饥荒提供了一个准实验环境，用于测试长期和严重饥荒对长期营养不良和贫困背景下认知发展的影响，这是人类历史上大多数饥荒以及发达国家和发展中国家贫困人口的共同背景。我们建议使用中国第二次全国残疾调查（CSNSD）的数据，这是中国最新的全国残疾调查。我们将采用一种新颖的方法来测量中国县级饥荒的强度，采用稳健的差中差估计器将家庭影响与其他潜在的混杂因素隔离开来。我们将研究在饥荒之前（1956-58）、期间（1959-61）和之后（1962-1964）出生的出生队列，并探讨影响如何随暴露于饥荒的时间、性别和城市/农村出身而变化。共有174,988名男性和173,688名女性将被纳入我们的研究。我们的一般假设是，在生命的前1000天（而不是之后的1000天）暴露在饥荒中会导致a)智力残疾、视觉、语言、听力、精神和身体残疾的风险更高，上学的机会更少；B)男性的影响大于女性，因为男性的生理脆弱性更大；C)由于农村地区的饥荒更严重，对农村居民的影响比城市居民更大。我们的研究团队在中国饥荒和队列研究、残疾研究以及CSNSD数据的设计和使用方面提供广泛的专业知识。我们希望我们的发现能够丰富有关营养和认知发展的文献，并可能支持在贫穷国家和发达国家（如美国）的高风险人群中改善孕期和幼儿期营养的重要性。

DESCRIPTION (provided by applicant): Our goal is to advance understanding of the role of nutrition during the first 1000 days of life (conception to age 2y), a critical and vulnerable phas in brain development, on intellectual and other disabilities, as well as on schooling. We propose a study of the long term effects of the 1959-61 Chinese famine, the largest in human history with up to 30-50 million deaths. The famine provides a quasi-experimental setting for testing effects of exposure to prolonged and severe famine on cognitive development in the context of chronic undernutrition and poverty, the context common to most famines in human history and to poor populations in both developed and developing countries. We propose to use the data from the China Second National Survey on Disability (CSNSD), the most up-to-date national survey on disability in China. We will apply a robust difference-in- difference estimator to isolate the famie impact from other potential confounding factors using a novel approach to measuring the intensity of the Chinese famine at county level. We will study birth cohorts born before (1956-58), during (1959-61) and after the famine (1962-1964) and explore how impact varies by timing of exposure to the famine, sex and urban/rural origin. A total of 174,988 men and 173,688 women will be included in our study. Our general hypothesis is that exposure to the famine during the first 1000 days of life, but not later, leads to a) higher risk of intellectual disabiliy and visual, speech, hearing, psychiatric, and physical disabilities, and less schooling; b) larger impact among men than women due to the greater biological vulnerability of men; c) larger impact among rural than urban residents due to the greater severity of the famine in rural areas. Our research team provides extensive expertise in Chinese famine and cohort research, disability research, and design and use of the CSNSD data. We expect our findings to enrich the literature regarding nutrition and cognitive development and possibly to support the importance of improving nutrition in pregnancy and early childhood among high risk population in both poor countries as well as developed countries such as the US.